MU_CAMATT2.20.pdf

User’s guide

November 2011 Tunnels Study Centre

www.cetu.developpement-durable.gouv.fr

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CAMATT 2.20User’s guide

November 2011

Software

WARNINGThis software has been developed through research conducted or commissioned by CETU and targets experienced professionals. While every possible precaution has been taken during their development and validation, they may contain errors. Under no circumstances may CETU be deemed liable for any direct or indirect damage that may be caused by using this software. Any users who detect errors or inaccuracies when deploying the software are invited to notify CETU.

Tunnels Study Centre25, avenue François MitterrandCase n°169674 BRON - FRANCETél.: 33 (0)4 72 14 34 00 – Fax: 33 (0)4 72 14 34 30cetu@developpement-durable.gouv.frwww.cetu.developpement-durable.gouv.fr

CONTENTS

1 GETTING STARTED WITH CAMATT 2.20__________________________________5

1.1 Presentation of the application 5

1.2 Installing, launching and uninstalling the application 51.2.1 Windows 51.2.2 Linux 6

1.3 General working scheme 7

2 USING CAMATT 2.20__________________________________________________8

2.1 Presentation of the main interface 8

2.2 Menus 92.2.1 “File” menu 9

New 9Open 9Close 10Close all 10Save 10Save as 11Save all 11Duplicate 11Print preview 12Print 13Preferences 13Recent documents 13Quit 14

2.2.2 “Edit” menu 15Undo 15Redo 15Delete 15Selection mode 15Select all 16Previous 16Next 16Zoom in 16Zoom out 16Zoom box 17View all 17Move 17Grid 17Group devices 17Ungroup devices 17

2.2.3 “Network” menu 18Tunnel 18Ramp 22Jet fan array 24Injector 25Blowing vent 26Extraction damper 27Massive extraction 28Local head loss 29Aeraulic transparency 30Traffic interruption 31Fire 32

2.2.4 “Parameters” menu 34Tunnel / Ramps 34

“Tunnel sections” tab 35“Ramps” tab 36“Local head losses” tab 37

Devices 38“Distributed ventilation” tab 40“Jet fans” tab 40“Injectors” tab 40

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“Blowing vents” tab 41“Extraction dampers” tab 41“Massive extraction” tab 41“Aeraulic Transparencies” tab 42“Traffic Interruptions” tab 42The button 42The and buttons 43

Pressure at portals 44Fire 46Pollution 47Traffic 48Environment 49Data summary 50

2.2.5 “Simulation” menu 51Fire mode 51Pollution mode 51

2.2.6 “Results” menu 53Plot results 53

Curves f(x) and f(t) 54Contour lines f(x,t) 56Viewing out-of-service jet fans 57

Show traffic 58Export results 59Export traffic results 61

2.2.7 “Libraries” menu 62Wall materials 62Pollutants 63

2.2.8 “?” menu 66Help… 66About… 66

2.3 Toolbar 67

2.4 Drawing sheet 692.4.1 Drawing area 692.4.2 Banner 70

Ramp angle 70Slopes of tunnel sections 70Tunnel orientation 70Devices 71

2.4.3 Legend 712.4.4 Scale 71

3 SOLVED EQUATIONS________________________________________________72

3.1 Conservation of mass 72

3.2 Conservation of the momentum 723.2.1 Linear source terms (or sinks) 74

Buoyancy forces 74Drag (air friction) forces on tunnel walls 74Vehicle forces on the air 74

3.2.2 Local source terms (or sinks) 76Driving forces communicated to the air by a jet fan array 76Driving forces communicated to the air by an injector 76Forces due to air drag in turbulence zones 76

3.3 Conservation of enthalpy 773.3.1 Amount of heat emitted by the seat of the fire 773.3.2 Convective heat transfers with walls 783.3.3 Radiant heat transfers with walls 783.3.4 Transfers of heat during air blowing 78

Distributed blowing vents 79Local blowing vents 79Injectors 79Aeraulic transparencies 79Air entering via the portals 80

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3.3.5 Transfers of heat during air extraction 80Distributed extraction dampers 81Local extraction dampers 81Massive extractions 81Aeraulic transparencies 81Air exiting via the portals 82

3.4 Heating of walls 82

3.5 Thermodynamic equations 833.5.1 Equation of state 833.5.2 Specific enthalpy 83

3.6 Transport of a passive scalar 843.6.1 Gaseous pollutants 84

Emissions of gaseous pollutants from the seat of a fire 85Emissions of gaseous pollutants by road traffic 85Distributed blowing vents 85Distributed extraction dampers 86Local blowing vents 86Local extraction dampers 86Injectors 86Massive extractions 86Aeraulic transparencies 87Air entering via the portals 87Air exiting via the portals 87

3.6.2 Air opacity 88Emissions of soot from the seat of a fire 89Emissions of particulates from road traffic 89Distributed blowing vents 89Distributed extraction dampers 89Local blowing vents 90Local extraction dampers 90Injectors 90Massive extractions 90Aeraulic transparencies 91Air entering via the portals 91Air exiting via the portals 91

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1 GETTING STARTED WITH CAMATT 2.20

1.1 Presentation of the applicationAnnex 1 of the French inter-ministerial circular No. 2000-63 of 25 August 2000 relating to safety in the French road tunnel network requires a safety dossier for all tunnels exceeding 300 m in length. In particular, this dossier includes a specific hazard investigation, describing the accidents, of any origin whatsoever, that are likely to occur during operational phases, together with their type and the magnitude of their possible impact. In 2003, in order to assess the impacts of an in-tunnel fire and, more specifically, to describe the changes that take place in ambient tunnel conditions, mainly in the first 30 minutes following an outbreak of fire, the CETU developed CAMATT1 to model road tunnel airflow in the presence of fire.

In addition to this specific use for hazards studies, CAMATT is also used to size road tunnel ventilation systems.

Eight years of use of CAMATT revealed the need to develop a new release, the 2.20, aimed at correcting the various listed bugs, improving the numerical convergence of calculations and integrating a new graphical user interface, together with new functionalities such as:

an option for modelling fires, traffic or equipment in a ramp

an option for viewing traffic distribution within a tunnel and any related ramps at any given moment in time

a module for making calculations under stationary operating conditions used to model the distribution of pollutants in a tunnel and any related ramps during normal operating conditions

the portability of the solver and the graphics interface to Linux

1.2 Installing, launching and uninstalling the application

1.2.1 Windows

Description of the installation

As default, CAMATT 2.20 is installed in the C:\Program Files\CAMATT 2.20 folder. After the installation, the CAMATT 2.20 file tree looks like this:

The aide folder contains on-line software support in the form of a PDF file.

The bin folder contains the executable version of the software together with the libraries required for its correct operation (bin\lib folder).

The jre folder contains the virtual JAVA machine used to self-start the JAVA programme (with no additional installation).

For each machine user, a folder named .camatt is created in their folder C:\Documents and Settings\loginUtilisateur the first time the application is launched.

This folder contains the following directories:

1 Acronym for CAlcul Mono-dimensionnel Anisotherme Transitoire en Tunnel (one-dimensional anisothermal transient calculation in tunnels)

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bddThis folder contains the bdd.xml file grouping all the pollutant and material characteristics. This file is updated via the application’s graphical interface.

ExportThis folder is automatically used to save all the *.csv files that can be exported from the application’s graphics interface (data summary, aeraulics calculation result or traffic distribution for the selected scenario at any given time).

PreferencesThis folder contains the .xml file preferences that group all the application preferences defined by the user using the “Preferences” command in the “File” menu, i.e.:▪ export folder for the data and results summary▪ pollutant definition units (ppm or mg/m3)▪ drawing sheet and curve parameters

▫ colour and thickness of the lines symbolising tunnels or ramps▫ show or hide the scale▫ show or hide the grid▫ show or hide the key▫ show or hide out-of-service jet fans on the curves

▪ the list of buttons on the toolbar

Launch

To launch CAMATT 2.20, double-click the icon generated automatically on the desktop during the installation process.

The application can also be accessed via the Start/Programs/CAMATT 2.20 menu or by double-clicking on a *.cmf scenario file generated by the application.

Illustration:

When using CAMATT 2.20 for the first time, it is recommended to select the work folder to which will be exported the files that can be generated by CAMATT 2.20. To do this, use the “Preferences” command in the “File” menu.

Uninstall

To uninstall CAMATT 2.20, click Uninstall CAMATT 2.20 in the Start/Programs/CAMATT 2.20 menu. You also need to delete the .camatt folder located in the directory C:\Documents and Settings\loginUtilisateur for each user.

1.2.2 Linux

Description of the installation

When the camatt-2.20-EN-linux.tar.gz package (or camatt-2.20-FR-linux.tar.gz for the French version) is uncompressed in a folder of the user choice, the CAMATT-2.20 directory is created. The file tree in this folder is as follow:

The aide folder contains on-line software support in the form of a PDF file.

The bin folder contains the executable version of the software together with the libraries required for its correct operation (bin\lib folder).

The jre folder contains the virtual JAVA machine used to self-start the JAVA programme (with no additional installation).

For each machine user, a .camatt folder is created in their $HOME folder the first time the application is launched.

This folder contains the following directories:

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bddThis folder contains the bdd.xml file that groups all the pollutant and material characteristics. This file is updated via the application’s graphics interface.

ExportThis folder is automatically used to save all the csv files that can be exported from the application’s graphics interface (data summary, aeraulics calculation result or traffic distribution for the selected scenario at any given time).

PreferencesThis folder contains the .xml file preferences that group all the application preferences defined by the user using the “Preferences” command in the “File” menu, i.e.:▪ export folder for the data and results summary▪ pollutant definition units (ppm or mg/m3)▪ drawing sheet and curve parameters

▫ colour and thickness of the lines symbolising the tunnel or ramps▫ show or hide the scale▫ show or hide the grid▫ show or hide the key▫ show or hide out-of-service jet fans on the curves

▪ the list of buttons on the toolbar

Launch

To launch CAMATT 2.20, double-click the camatt-2.20.sh script located at the root level in the CAMATT 2.20 directory in the install folder.

The application can also be launched by typing the following command line in the install directory: ./camatt-2.20.sh

Uninstall

To uninstall CAMATT 2.20, you need to delete the folder CAMATT 2.20 and also the .camatt folder located in your $HOME directory.

1.3 General working schemeCAMATT 2.20 simulations are performed based on scenarios saved in XML files with a *.cmf extension.

A scenario corresponds to a tunnel with its ramps, if any, and its equipment modelled in a drawing sheet and linked to a set of time, environment and traffic parameters that make it possible to run the simulation.

Before being able to run a simulation though, it is vital to enter all the scenario elements such as the characteristics of the tunnel and any related ramps, the equipment and their related controls, the traffic, the fire and its evolution, etc. Until these elements have been entered, the commands in the “Results” menu used to launch the simulations remain shaded.

Once a simulation has been run, the results are recorded when saving the scenario to a binary file with a *.res extension given the same name as the scenario.

Simulation results can be accessed via the commands in the “Results” menu that remains shaded until the simulation has been completed. They can be viewed using the curves describing airflow (velocity, flow rate, total pressure or static pressure), changes in ambient conditions (air temperature and pollutant concentrations) and wall temperatures in the tunnel or any related ramps. They can also be exported to a *.csv file that will be saved in the selected folder using the “Preferences” command in the “File” menu.

WARNING

*.cmf files generated under CAMATT 1.13 to describe a scenario are not compatible with CAMATT 2.20.

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2 USING CAMATT 2.20

2.1 Presentation of the main interfaceThe main interface of the CAMATT 2.20 release comprises:

a menu bar

a toolbar

a drawing sheet

Illustration:

These three elements are described in sections 2.2, 2.3 and 2.4 of this User Guide.

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Drawing sheet

MenusToolbar

2.2 Menus

2.2.1 “File” menu

The “File” menu in the menu bar is mainly used to handle scenarios (create, open, close, save, print and duplicate) and to access application preferences.

Illustration:

New

This command is used to open a new blank drawing sheet.

This new drawing sheet is named “Scenarioi” where i is the number of new drawing sheets created by the user. Note that the blank drawing sheet “Scenario1” is generated automatically on opening CAMATT.

This command can also be accessed via the keyboard shortcut Ctrl+N.

The user can create as many new drawing sheets as they wish and switch between them by simply clicking on the corresponding tab.

Illustration:

Open

This command is used to open an existing scenario using a dialog in which the user selects the *.cmf file to be opened, then clicks .

This command can also be accessed via the keyboard shortcut Ctrl+O.

The user can also select several files to be opened using the Ctrl or Shift keys. Each scenario is then loaded in a tab.

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Illustration:

Illustration:

Close

This command is used to close the selected scenario.

If the user has made changes, a message is displayed asking them whether they want to save the changes made to the current scenario.

Any scenarios that have been changed but not saved are identified by a star (*) next to the scenario’s name.

The user can also close a scenario by clicking the cross on the left side of the tab.

Illustration:

Illustration:

Close all

This command is used to close all the open scenarios.

If the user has made changes to one or more scenarios, a message is displayed for each modified scenario, asking them whether they want to save the changes.

Save

This command is used to save the selected scenario as a *.cmf file.

This command can also be accessed via the keyboard shortcut Ctrl+S.

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If the scenario has already been saved, the previous file version is overwritten.

If the user is saving the scenario for the first time, they are invited to select the file name and the folder via a dialog.

There are no restrictions on the file name or location of a folder (hard disk or network).

Illustration:

Save as

This command is used to save the selected scenario as a *.cmf file using a dialog in which the user can select the file name and folder.

There are no restrictions on the file name or location of the folder (hard disk or network).

Save all

This command is used to save each open scenario as a *.cmf file.

Scenarios are automatically given the file name “Name of the scenario.cmf”. Also, if the folder already contains a file of the type “Name of the scenario .cmf", the previous file version is overwritten.

If the user is saving one or more scenarios for the first time, they are invited to select a file name and folder for each scenario via a dialog.

There are no restrictions on the file name or location of the folder (hard disk or network).

Duplicate

This command is used to duplicate the selected scenario in full.

CAMATT then automatically generates a new scenario by copying the modelled tunnel into a new drawing sheet (new tab) that contains all the parameters for the selected scenario.

While this duplicate has exactly the same parameters as the originating scenario, these two scenarios are completely separate. Changing a parameter on one of the scenarios has no effect on the parameters of the other scenario.

This new scenario is automatically named “Scenarioi” where i is the number of new scenarios created by the user; i is always strictly greater than 1 as the “Scenario1” scenario is generated automatically on opening CAMATT.

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Illustration:

Print preview

This command launches a graphics interface used to show the diagram as it will be printed when the user starts the print.

This interface is also used to change the layout of the document to be printed and to start the print using the and buttons respectively.

Illustration:

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Print

This command is used to print the part of the selected drawing sheet that can be seen on the display using a dialog in which the user can enter the printing parameters:

choice of printer

properties of the selected printer

number of copies

Illustration:

Preferences

This command is used to open the application preferences dialog that lets the user change the following items:

export directories for the results and data summary

pollutant definition unit (ppm or mg/m3)

drawing sheet and curve parameters▪ colour and thickness of the lines symbolising the tunnel or ramps▪ show or hide the scale▪ show or hide the grid▪ show or hide the key▪ show or hide out-of-service jet fans on the curves

show buttons on the toolbar

Illustration:

Recent documents

This command is used for quick access to the last five documents opened by the user and opens a scenario directly (selected from the list of most recently opened documents) without using the “Open” command in the “File” menu.

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Illustration:

Quit

This command is used to close and quit the application.

If the user changes one or more scenarios before closing and quitting the application, a dialog is displayed asking them whether they wish to save the changes made to the scenarios.

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2.2.2 “Edit” menu

The “Edit” menu in the menu bar is used to access the various commands specific to the drawing sheet.

This menu is also used to group and ungroup equipment of the same type.

Illustration:

Undo

This command is used to cancel the last action performed on the drawing sheet. For example, it lets the user cancel the insertion of an element, or delete or move an element. This command does not, however, have any effect on the zoom.

This command can also be accessed via the keyboard shortcut Ctrl+Z.

Redo

This command is used to repeat the last action cancelled on the drawing sheet, except where this involved an action on the zoom.

This command can also be accessed via the keyboard shortcut Ctrl+Y.

Delete

This command is used to delete one or more elements previously selected by the user.

This command can also be accessed via the keyboard shortcut Del.

Selection mode

Switching to the application’s select mode selects one or more elements in the drawing sheet in order to delete or move them. If several equipment of the same type are selected, they can be grouped in order to define a single control for them all.

When the application is in select mode, the toolbar button is shown on a white background and a tick appears in front of the corresponding menu.

Illustration:

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The chosen element is selected by clicking on it; the element can be moved by left-clicking the selected element and then dragging it.

When a tunnel section (or ramp) is selected, it is highlighted by the display of a green square at each edge. When one of these edges also corresponds to one of the ends of the tunnel, a red rather than a green square is displayed.

Illustration:

When a piece of equipment is selected, it is highlighted by the display of four yellow squares outlining it.

Illustration:

When a group of equipment is selected, it is highlighted by the display of four green squares outlining each piece of selected equipment. Selecting one element in a group results in the automatic selection of all the other elements in this group.

Illustration:

Several elements can be selected simultaneously by pressing the Ctrl key when selecting each equipment using the mouse, or by selecting an area in the window by left-clicking the mouse while dragging it.

Select all

This command is used to simultaneously select all the elements in the diagram.

This command can also be accessed via the keyboard shortcut Ctrl+A.

Illustration:

Previous

This command is used to cancel the last action performed on the zoom and to go back to the image’s previous display.

Next

This command can only be accessed if the “Previous” command has been used, otherwise it remains shaded.

It is therefore used to cancel the last action performed on the zoom with the “Previous” command and to go back to the image’s previous display.

Zoom in

This command is used to zoom in on the drawing sheet.

Zoom out

This command is used to zoom out on the drawing sheet.

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Zoom box

This command is used to zoom in or out of an area on the selected drawing sheet that the user has selected within a rectangle using the mouse.

View all

This command is used to automatically adjust the zoom to give an overall view of the modelled tunnel.

Move

Switching to the application’s pan mode lets the user move the whole diagram around the drawing sheet using the mouse, i.e. in order to centre it.

When the application is in pan mode, the toolbar button is shown on a white background, a tick appears in front of the corresponding menu and the mouse pointer is shown as a hand.

Illustration:

Grid

This command is used to display or delete the drawing sheet grid. This grid helps to place elements on the drawing sheet.

The grid is automatically displayed on the drawing sheet area. However, the user can mask it if they wish using the “Preferences” command in the “File” menu.

When the grid is displayed, the toolbar button is shown on a white background and a tick appears in front of the corresponding menu.

Illustration:

Group devices

This command is used to group several devices of the same type that were previously selected by the user so as to enter their control characteristics in one single, simultaneous action; a single device can only belong to one group.

The devices to be grouped are selected by pressing the Ctrl key when selecting each piece of equipment with the mouse, or by using the mouse to select an area in the window by left-clicking the mouse and dragging it.

If the user selects a device already belonging to a group, all devices in that group will be selected, each one being outlined by four green squares.

Ungroup devices

This command is used to ungroup devices of the same type that were previously grouped earlier by the user.

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2.2.3 “Network” menu

The “Network” menu in the menu bar is used to model the tunnel with, where applicable, its ramps, ventilation equipment and closure systems.

Illustration:

On opening a new drawing sheet, all the commands are shaded except for those used to model a tunnel.

Modelling a tunnel on the drawing sheet activates all other commands and deactivates that used to model a tunnel as only one tunnel can be modelled on the drawing sheet at any given time.

Tunnel

This command is used to insert a tunnel comprising one or more sections in the drawing sheet.

Each tunnel section is delineated by two nodes:

one “upstream” node corresponding to the first node created on the drawing sheet

one “downstream” node corresponding to the second node created on the drawing sheet

Note that, even after having inserted a tunnel on the drawing sheet, you can still change the length of the tunnel or add a tunnel section by acting directly on the drawing sheet rather than using the “Tunnel” command, which has been deactivated.

► To insert a tunnel on the drawing sheet

1) Select the “Tunnel” command.

Illustration:

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2) First, left-click on the drawing sheet with the mouse.

A left-click of the mouse creates the upstream node for the first tunnel section.

Illustration:

3) Move the mouse without clicking.

The length of the inserted tunnel section is displayed for information.

Illustration:

4) Click on the drawing sheet a second time using a right or left-click of the mouse.

A left-click creates the downstream node for the section maintaining the “draw tunnel section” mode active. The user can therefore create as many sections as they wish by repeating operation 3 with a left-click of the mouse.

The right-click is used to create the downstream node of the section by deactivating the “draw tunnel section” mode. This action is used to create the downstream node for the last tunnel

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left click

section.

Illustration of a right-click (tunnel with a single section):

Illustration with a left-click, followed by a right-click (tunnel with two sections):

Right-clicking on the mouse also automatically generates a local head loss and imposed pressure condition at each end of the tunnel.

► To change the length of a tunnel section via the drawing sheet

1) Switch to the select mode using the “Select mode” command in the “Edit” menu where necessary, then left-click the mouse to select the tunnel section that needs to have its length changed.

2) Point the mouse on the upstream or downstream node of the end of the selected tunnel section and then left-click the mouse.

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right click

left click

right click

Illustration:

3) Left-click and drag the mouse.

The new length of the tunnel section is displayed for information.

Illustration:

4) Release the mouse’s left button to place the node in its new position.

► To add a tunnel section via the drawing sheet

1) Switch to the select mode using the “Select mode” command in the “Edit” menu where necessary, then left-click the mouse to select the tunnel end section to which the new tunnel section is to be added.

2) Point the mouse on the tunnel end’s upstream or downstream node depending on which end section has been selected, then press the Ctrl key and left-click the mouse.

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left click

withleft

click

Illustration with the most downstream end section selected:

3) Left-click and drag the mouse while holding down the Ctrl key.

The length of the newly inserted tunnel section is displayed for information.

Illustration:

4) Release the mouse’s left button to position the upstream or downstream node of the newly inserted tunnel section depending on which end section has been selected.

Releasing the left button deactivates the “tunnel line” mode and automatically relocates the head loss and the imposed pressure condition to the new tunnel portal.

Ramp

This command is used to insert a ramp with a single section.

Ramps can only be inserted at the junction between two tunnel sections. It is therefore impossible to place a ramp at the end of tunnel.

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leftclik

+Ctrl

withleft

click+

Ctrl

It is also impossible to place two concurrent ramps at the same junction between two tunnel sections.

► To insert a ramp on the drawing sheet

1) Switch to the select mode using the “Select mode” command in the “Edit” menu where necessary, then select one of the two sections between which the ramp is to be inserted.

2) Select the “Ramp”command.

Illustration:

3) Point the mouse on the node corresponding to the junction between the tunnel and the ramp and left-click on the mouse.

Illustration:

4) Drag the mouse while holding the left button in a direction other than that of the tunnel.

The length of the inserted ramp is displayed for information.

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left click

Illustration:

5) Release the mouse’s left button to position the ramp’s upstream node2.

Releasing the left button deactivates the “ramp line” mode and automatically generates a head loss and an imposed pressure condition at the end of the ramp.

Jet fan array

This command is used to insert a jet fan array in tunnel or a ramp.

A jet fan is a fan attached to a tunnel wall or ceiling that is used to add a local momentum source term in the longitudinal direction without adding a mass source term. A jet fan array consists in a group of several jet fans installed at the same location.

► To insert a jet fan array into a drawing sheet

1) Select the “Jet fan array” command.

Illustration:

When this command is activated, the button in the toolbar is shown on a white background and the symbol appears in front of the corresponding command.

2 CAMATT 2.20 automatically generates an entrance ramp

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Illustration:

2) Point the mouse at the place where the jet fan array is to be inserted and left-click on the mouse.

The array is then added to the drawing sheet and the jet fan characteristics can be entered via the “Parameters” menu.

Illustration:

To add other jet fan arrays, just repeat this operation as many times as necessary using the mouse’s left button.

3) Once all the jet fan arrays have been added, select the “jet fan array” command to deactivate it. The toolbar button no longer appears on a white background and the symbol is no longer visible in front of the corresponding command.

This command is also deactivated automatically if another command is activated.

Once all the jet fan arrays have been added, the “Group devices” command in the “Edit” menu can be used to regroup several jet fan arrays so as to define their joint control characteristics.

Injector

This command is used to insert an injector in a tunnel or a ramp.

An injector is a fan that is located either in a ventilation plant or in a duct, and used to deliver a directional jet of outside air into a tunnel. It can therefore be used to make local additions of both a momentum source term in the longitudinal direction and a mass source term.

► To insert an injector on the drawing sheet

1) Select the “Injector” command.

When this command is activated, the button in the toolbar is shown on a white background and a tick appears in front of the corresponding command.

Illustration:

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left click

2) Point the mouse at the place where the injector is to be inserted and left-click on the mouse.

The injector is then added to the drawing sheet and its characteristics can be entered via the “Parameters” menu.

Illustration:

To add other injectors, just repeat this operation as many times as necessary using the mouse’s left button.

3) Once all the injectors have been added, select the “Injectors” command to deactivate it. The toolbar button no longer appears on a white background and the symbol is no longer visible in front of the corresponding command.


Once all the injectors have been added, the “Group devices” command in the “Edit” menu can be used to regroup several injectors so as to define their joint control characteristics.

Blowing vent

This command is used to insert a blowing vent in a tunnel or a ramp.

A blowing vent is used to blow external air into a tunnel at ambient temperature, perpendicular to the airflow in the tunnel. It can therefore be used to make local additions of a mass source term without adding a momentum source term.

► To insert a blowing vent in the drawing sheet

1) Select the “Blowing vent” command.


Illustration:

2) Point the mouse at the place where the blowing vent is to be inserted and left-click on the mouse.


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left click

Illustration:

To add other blowing vents, just repeat this operation as many times as necessary using the mouse’s left button.

3) Once all the blowing vents have been added, select the “Blowing vents” command to deactivate it. The toolbar button no longer appears on a white background and the symbol is no longer visible in front of the corresponding command.


Once all the blowing vents have been added, the “Group devices” command in the “Edit” menu can be used to regroup several blowing vents so as to define their joint control characteristics.

Extraction damper

This command is used to insert an extraction damper in a tunnel or a ramp.

An extraction damper is used to extract air from the tunnel locally as required perpendicular to the airflow in the tunnel. It therefore makes it possible to extract mass source terms locally without adding a momentum source term.

NOTE

In contrast to massive extraction, the mass flow rate extracted by an extraction damper does not depend on the temperature of the extracted air. It is therefore constant and equal to ρoQv,

where ρo is the density of ambient air and Qv is the flow rate of the extraction device located upstream of the extraction damper. This assumes, therefore, that the extraction fans are located in an area sufficiently far away from the fire not to be affected by the temperature.

► To insert an extraction damper into the drawing sheet

1) Select the “Extraction damper” command.

When this command is activated, the button in the toolbar is shown on a white background and the symbol appears in front of the corresponding menu.

Illustration:

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left click

2) Point the mouse at the place where the extraction damper is to be inserted and left-click on the mouse.

The extraction damper is then added to the drawing sheet and its characteristics can be entered via the “Parameters” menu.

Illustration:

To add other extraction dampers, just repeat this operation as many times as necessary using the mouse’s left button.

3) Once all the extraction dampers have been added, select the “Extraction damper” command to deactivate it. The toolbar button no longer appears on a white background and the symbol is no longer visible in front of the corresponding command.


Once all the extraction dampers have been added, the “Group devices” command in the “Edit” menu can be used to regroup several extraction dampers so as to define their joint control characteristics.

Massive extraction

This command is used to insert a massive extraction in a tunnel or a ramp.

As with an extraction damper, a massive extraction is used to extract air from the tunnel locally, perpendicular to the airflow in the tunnel. It therefore makes it possible to extract mass source terms locally without adding a momentum source term.

NOTE

In contrast to an extraction damper, the mass flow rate extracted by a massive extraction depends on the temperature of the extracted air. This equals ρQv, where ρ is the density of air in the tunnel opposite the massive extraction and Qv is the massive extraction flow rate. This therefore assumes that the extraction fans are located in the immediate vicinity of the extraction point.

► To insert a massive extraction into the drawing sheet

1) Select the “Massive extraction” command.


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left click

Illustration:

2) Point the mouse on the tunnel at the place where the massive extraction is to be inserted and left-click on the mouse.

The massive extraction is then added to the drawing sheet and its characteristics can be entered via the “Parameters” menu.

Illustration:

To add other massive extractions, just repeat this operation as many times as necessary using the mouse’s left button.

3) Once all the massive extractions have been added, select the “Massive extraction” command to deactivate it. The toolbar button no longer appears on white background and the symbol is no longer visible in front of the corresponding command.


Once all the massive extractions have been added, the “Group devices” command in the “Edit” menu can be used to regroup several massive extractions so as to define their joint control characteristics.

Local head loss

This command is used to insert a local head loss in a tunnel or ramp, generally caused by a sudden change in the cross-section area.

► To insert a head loss in the drawing sheet

1) Select the “Local head loss” command.


Illustration:

29

left click

2) Point the mouse at the place where the local head loss is to be inserted and left-click on the mouse.

The local head loss is then added to the drawing sheet and its characteristics can be entered via the “Parameters” menu.

Illustration:

To add other local head losses, just repeat this operation as many times as necessary using the mouse’s left button.

3) Once all the local head losses have been added, select the “Local head loss” command to deactivate it. The toolbar button no longer appears on a white background and the symbol is no longer visible in front of the corresponding command.


Aeraulic transparency

This command is used to insert an aeraulic transparency in a tunnel or ramp.

An aeraulic transparency is a large ceiling opening that connects with the outside. Depending on the sign of the pressure difference on either side of the aeraulic transparency, air is either extracted from or blown into the tunnel. This exchange is always perpendicular to the airflow in the tunnel. Therefore, depending on the sign of the pressure difference on either side, an aeraulic transparency is used to locally subtract or add a mass source term without adding a momentum source term.

NOTE

An aeraulic transparency is modelled as a local head loss with a coefficient of 1.5 corresponding to a narrowing and then a sudden widening, scaled to the cross-section of the aeraulic transparency, followed by pressurizing to ambient pressure. When air is extracted from the tunnel, its temperature is that of the air in the tunnel opposite the aeraulic transparency; when air is blown into the tunnel, its temperature is that of ambient air.

► To insert an aeraulic transparency in the drawing sheet

1) Select the “Aeraulic transparency” command.

When this command is activated, the button of the toolbar is shown on a white background and the symbol appears in front of the corresponding command.

30

left click

Illustration:

2) Point the mouse at the place where the aeraulic transparency is to be inserted and left-click on the mouse.

The aeraulic transparency is then added in the drawing sheet and its characteristics can be entered via the menu “Parameters".

Illustration:

To add other aeraulic transparencies, just repeat this operation as many times as necessary using the mouse’s left button.

3) Once all the aeraulic transparencies have been added, select the “Aeraulic transparency” command to deactivate it. The toolbar button no longer appears on a white background and the

symbol is no longer visible in front of the corresponding command.


Once all the aeraulic transparencies have been added, the “Group devices” command in the “Edit” menu can be used to regroup several aeraulic transparencies so as to define their joint control characteristics.

Traffic interruption

This command is used to insert a traffic interruption in a tunnel or ramp.

A traffic interruption is a barrier, traffic light or any other system used to stop vehicles located upstream (in relation to the direction of traffic).

► To insert a traffic interruption in the drawing sheet

1) Select the “traffic interruption” command.


Illustration:

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Leftclick

2) Point the mouse at the place where the traffic interruption is to be inserted and left-click on the mouse.

The traffic interruption is then added to the drawing sheet and its control characteristics can be entered via the “Parameters” menu.

Illustration:

To add other traffic interruptions, just repeat this operation as many times as necessary using the mouse’s left button.

3) Once all the traffic interruptions have been added, select the “traffic interruption” command to deactivate it. The toolbar button no longer appears on a white background and the symbol is no longer visible in front of the corresponding command.


Once all the traffic interruptions have been added, the “Group devices” command in the “Edit” menu can be used to regroup several aeraulic transparencies so as to define their joint control characteristics.

Fire

This command is used to insert a fire in a tunnel or ramp.

Only one single fire can be modelled.

► To insert a fire in the drawing sheet

1) Select the “Fire” command.


Illustration:

2) Point the mouse at the place where fire is to be inserted and left-click on the mouse.

The fire is then added to the drawing sheet and its characteristics can be entered via the “Parameters” menu.

32

left click

Illustration:

3) Once the fire has been added, the command is automatically deactivated as only one single fire can be modelled at a time. The toolbar button is shaded and the symbol is no longer visible in front of the corresponding command.

33

left click

2.2.4 “Parameters” menu

The “Parameters” menu in the menu bar is used to enter all the data for the model, thereby parametering:

tunnel sections and any ramps

equipment and their controls

pressure conditions at interfaces with the outside

fire

pollutant concentrations in ambient air

traffic

tunnel environment

This menu is also used to export a *.txt file summarizing the data for the model entered by the user.

Illustration:

On opening a new drawing sheet, all the commands are shaded except for that used to define the tunnel environment.

Modelling a tunnel and any related ramps and equipment using the “Network” menu activates all the commands, with the exception of the “Fire” and “Data summary” commands.

The “Fire” command is only activated if a fire has been modelled in the drawing sheet using the “Fire” command in the “Network” menu.

The “Data summary” command is only activated when all the elements modelled in the drawing sheet using the “Network” menus (tunnel, ramps, equipment and fire) have been fully parametered using the “Tunnel / Ramps", “Devices” commands and, where applicable, the “Fire” command in the “Parameters” menu.

Illustration of a tunnel modelled with no fire on the drawing sheet:

Tunnel / Ramps

This command uses a dialog to enter the characteristics for the tunnel sections, ramps and local head losses that are automatically generated at the ends of a tunnel and at any related ramps for the selected scenario.

The dialog contains two or three tabs depending on whether there is a ramp.

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The first tab, entitled “Tunnel sections", is used to enter the characteristics of each tunnel section modelled in the drawing sheet.

The second tab, entitled “Ramps", is only displayed if a ramp has already been modelled in the drawing sheet. It is used to enter the characteristics of each ramp modelled in the drawing sheet.

The last tab, entitled “Local head losses", is used to enter local head loss coefficients at the ends of the tunnel and any ramps, where applicable.

Illustration of the “Tunnel sections” tab:

Illustration of the “Ramps” tab:

Illustration of the “Local head losses” tab:

The user moves around the tables either by pointing and then left-clicking the mouse on the fields to be selected, or by using the following keyboard keys:

select the cell content in the next column: Tab

select the cell content in the previous column: Maj + Tab

select the cell content in the next line: ↓

select the cell content in the previous line: ↑

NOTE

To be taken into account, the value entered in a field must be confirmed either by clicking outside the selected field, or by pressing the Enter key.

The following tables describe the fields to be filled in for each of the 3 tabs, their default value and their area of validity:

► “Tunnel sections” tab

Field Description Unit Default value Area of validity

Label Alphanumeric code used to name the tunnel section - Tunnel sect. No i (I) Character string

Length Length of the tunnel section mLength indicated when creating the section in the drawing sheet (II)

Positive real number

Cross-section area Cross-section through the tunnel section m2 0 (III) Real number belonging

to ]0;1000[

Perimeter Perimeter of the tunnel section or ramp m 0 (III) Positive real number

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Slope (- if downhill)

Value of the tunnel section slope in the upstream - downstream direction.

Negative if the tunnel section is descending and positive if it is rising

% 0 Real number

Friction coefficient Friction coefficient of the tunnel section walls - 0.025 Real number belonging

to ]0;1]

Material 1

First type of material used for the tunnel section walls. This is chosen from the list of wall materials defined in the “libraries” menu

- Concrete -

Material 2

Second type of material used for the tunnel section walls. This is chosen from the list of wall materials defined in the “libraries” menu

- Concrete -

Proportion ofmaterial 1

Proportion of material 1 in relation to material 2 in a part of the tunnel section

% 100 Real number belonging to ]0;100]

(I) i corresponds to the tunnel section creation ranking. If a ramp is inserted between tunnel sections i and i+1, tunnel sections ranked higher than i+1 are automatically incremented by 1.

(II) The length of the tunnel section is automatically updated by the application according to the position of the end nodes on the drawing sheet. Conversely, if the user modifies the length of the tunnel section in this field, the tunnel section modelled in the drawing sheet will be automatically updated.

(III) The default value does not belong in the area of validity; it must therefore be replaced by a valid value.

► “Ramps” tab


Label Alphanumeric code used to name the ramp - Ramp No. j (I) Character string

Length Length of the ramp mLength indicated when creating the ramp in the drawing sheet (II)


Cross-section area Cross-section of the ramp m2 0 (III) Real number belonging to ]0;1000[

Perimeter Perimeter of the ramp section m 0 (III) Positive real number

Slope (- if downhill)

Value of the ramp slope in the upstream - downstream direction. Negative if the ramp is descending and positive if it is rising

% 0 Real number

Friction coefficient Friction coefficient of the ramp walls - 0,025 Real number belonging to ]0;1]

Angle Angle of the ramp with the tunnel (IV) °Angle indicated when creating the ramp in the drawing sheet (V)

Real number belonging to ]0;90[

Orientation Entrance or exit ramp - Entrance Entrance and Exit

Traffic direction Direction of traffic flow in the tunnel associated with the ramp - Upstr. - Downst.

"Upstr. - Downst. “ and"Downst. Upstr. “

Material 1

First type of material used for the ramp wall. This is chosen from the list of wall materials defined in the “libraries” menu

- Concrete -

Material 2

Second type of material used for the ramp wall. This is chosen from the list of wall materials defined in the “libraries” menu

- Concrete -

Proportion ofmaterial 1

Proportion of material 1 in relation to material 2 in a section of the ramp % 100 Real number belonging

to ]0;100]

(I) If a ramp is inserted between tunnel sections i and i+1, j is equal to i+1; tunnel sections ranked higher than i+1 are automatically incremented by 1.(II) The length of the ramp is automatically updated by the application according to the position of the end nodes in the drawing sheet. Conversely, if

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the user modifies the length of the ramp in this field, the ramp modelled in the drawing sheet will be automatically updated.(III) The default value does not belong in the area of validity; it must therefore be replaced by a valid value.(IV) The angle has to be entered by taking account of the direction of traffic in the tunnel associated with the ramp and of the type of ramp entered via

the “Direction” and “Orientation” fields respectively.

If the direction of traffic in the tunnel associated with the ramp is “Upstream - Downstream", the angle to be entered is: for an entrance ramp, the angle between the tunnel section located upstream of the junction in the direction of traffic and the ramp for an exit ramp, the angle between the tunnel section located downstream of the junction in the direction of traffic and the ramp

If the direction of traffic in the tunnel associated with the ramp is “Downstream - Upstream", the angle to be entered is: for an entrance ramp, the angle between the tunnel section located downstream of the junction in the direction of traffic and the ramp for an exit ramp, the angle between the tunnel section located upstream of the junction in the direction of traffic and the ramp

The following table gives all the possible options:

"Traffic direction” field "Orientation” field Angle

Upstr. - Downst. Entrance

Upstr. - Downst. Exit

Downst. Upstr. Entrance

Downst. Upstr. Exit

(V) The default value does not necessarily belong to the area of validity; it must therefore be replaced by a valid value.

Once the dialog has been confirmed, the angle of the ramp is automatically updated in the drawing sheet according to the elements entered in the “Angle", “Orientation” and “Traffic direction” fields.

NOTE

In the CAMATT 2.20 release, the function used to take account of head losses at the junction has not been activated as it may cause digital divergence problems with certain flow regimes. Also, the value entered in the “Angle” field has no effect on the calculations. Conversely, this value has to belong to the area of validity ]0;90[.

► “Local head losses” tab


Label Alphanumeric code used to name the local head loss -

Portal loss No. i orLocal loss No. j (I) Character string

Local cross-section area

Cross-section through the tunnel section or ramp at the level of the local head loss

m2

Cross-section through the tunnel section or ramp at the level of the local head loss (II)

Non-modifiable

Reference cross-section area

Cross-section used to calculate the head loss (III) m2

Cross-section through the tunnel section or ramp at the level of the local head loss

Real number belonging to ]0;1000[

Upst. - Downst.Head loss coeff.

Coefficient representing the head loss for an airflow in the upstream - downstream direction

- 0 or 0.5 or 1 (IV) Positive real number

Downst. - Upst.Head loss coeff.

Coefficient representing the head loss for an airflow in the Downstream - Upstream direction

- 0 or 0.5 or 1 (IV) Positive real number

Dist. from upstream Position of the local head loss (V)

Calculated based on the position of the jet fan array in the drawing sheet (VI) or positioned 0.10 m from a portal

Non modifiable orReal number belonging to ]0;l tunnel[ or ]0;l ramp[

(I) Portal loss No.i describes the head loss located at the level of the tunnel portal. Portal loss No.1 describes the head loss located at the level of the tunnel portal corresponding to the tunnel’s upstream node.Portal loss No.2 describes the head loss located at the level of the tunnel portal corresponding to the tunnel’s downstream node.Portal loss No.i with i>2 describes the head loss located at the level of the ramp portal that always corresponds to a downstream node as the upstream node is the one located at the level of the junction with the tunnel. For each ramp, i takes the value n+2 where n corresponds to the creation ranking of the ramp in the drawing sheet.

Local loss No.k describes a local head loss. If a local head loss is inserted in a tunnel or ramp, k is equal to i max + 1. It is then incremented by 1 with each new insertion of a local head loss.

(II) The interior zone is displayed for information on an orange background and corresponds to the value entered in the “Cross-section area” fields of the “Tunnel sections” and “Ramps” tabs for the “Tunnels / Ramps” command.

(III) The “reference section” noted Sref appears in the expansion equation for the following head loss:

P= 12 Q2

Sref2

37

avecP : head loss : air density : head loss coefficient Q : flow rate

(IV) The head loss coefficient automatically equals 0 except for the head losses located at the portals of a tunnel or ramp.

For the head loss located at the level of the tunnel portal corresponding to the tunnel’s upstream node, the head loss coefficient in the upstream - downstream direction equals 0.5 and that in the Downstream - Upstream direction equals 1.

For the head loss located at the level of the tunnel portal corresponding to the tunnel’s downstream node, the head loss coefficient in the upstream - downstream direction equals 1 and that in the Downstream - Upstream direction equals 0.5.

For the head loss located at the level of the ramp portal that always corresponds to a downstream node, the head loss coefficient in the upstream - downstream direction equals 1 and that in the Downstream - Upstream direction equals 0.5.

(V) For a head loss located in the tunnel, the upstream distance corresponds to its position in relation to the tunnel’s upstream node.

For a head loss located in a ramp, the upstream distance corresponds to its position in relation to the portal of the ramp for an entrance ramp and in relation to its junction with the tunnel for an exit ramp.

(VI) Once the dialog has been confirmed, the position of the local head loss is automatically updated on the drawing sheet.

Devices

This command uses a dialog to enter the characteristics of all the equipment modelled in the drawing sheet for the selected scenario, i.e.:

jet fan arrays

injectors

blowing vents

extraction dampers

massive extractions

aeraulic transparencies

traffic interruptions

It is also used to enter, for each tunnel section and ramp in the drawing sheet, the characteristics of the distributed blown or extracted flow rate.

The dialog may therefore contain 1 to 8 tabs depending on the type of equipment modelled in the drawing sheet.

The first tab, entitled “Distributed ventilation", is used to enter the characteristics of the distributed blown or extracted flow rate for each tunnel section and ramp.

The other tabs, entitled “Jet fans", “Injectors", “Blowing vents", “Extraction dampers", “Massive extractions", “Aeraulic transparencies” and “Traffic interruptions” only appear in this order if the related equipment is modelled in the drawing sheet. They are used to enter the characteristics for each equipment.

Illustration of the “Distributed ventilation” tab:

Illustration of the “Jet fans” tab:

Illustration of the “Injectors” tab:

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Illustration of the “Blowing vents” tab:

Illustration of the “Extraction dampers” tab:

Illustration of the “Massive extractions” tab:

Illustration of the “Aeraulic transparencies” tab:

Illustration of the “Traffic interruptions” tab:

All the tabs in the dialog have the same structure; they contain:

fields used to characterise equipment and its location

for equipment blowing air into a tunnel or ramp, a button used to characterise pollutant concentrations in the blown air

a button used for individual equipment control

where applicable, a button that replaces the button used to simultaneously control several equipment of the same type that were previously grouped using the “Group” command in the “Edit” menu






NOTE

To be taken into account, the value entered in a field must be validated either by clicking outside the selected field, or by pressing the Enter key.

The following tables describe the fields characterising the equipment to be filled in for each of the 8 tabs, their default value and their area of validity:

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► “Distributed ventilation” tab


Label Name of the tunnel section or ramp - Tunnel section No. i orRamp No. j Non modifiable (I)

Distributed blowing flow rate

Value of the distributed blowing flow rate in the tunnel section

m3.s-1.m-1 0 Positive real number

Distributed extraction flow rate

Value of the distributed extraction flow rate

m3.s-1.m-1 0 Positive real number

(I) The description(s) automatically correspond to those entered in the “Label” fields of the “Tunnel sections” or “Ramps” tab of the “Tunnels / Ramps” command in the “Parameters” menu.

► “Jet fans” tab


Label Name of the jet fan array - Array No. i Character string

Number of jet fans Number of jet fans making up the array - 1 Positive whole number

Unit free-field thrustThrust of a jet fan in the array. All the jet fans in the array are assumed to be identical.

N 0 Real number

Jet velocity Speed at which air is ejected from a jet fan outlet m.s-1 30 Positive real number

EfficiencyOverall efficiency of the jet fan array, in particular, factoring in the effects of the wall

- 0,85 Real number belonging to ]0;1]

Max working temperature

Temperature above which the jet fan array is assumed to be destroyed °C 200 Positive real number

Reference densityAir density corresponding to the conditions under which the array’s jet fan performance was measured

kg.m-3 105 Positive real number

Tunnel cross-sect. area

Cross-section through the tunnel section or ramp at the level of the jet fan array

m2

Cross-section through the tunnel section or ramp at the level of the jet fan array (I)

Non modifiable

Cross-sect. areaat jet fans

Cross-section through the tunnel section or ramp opposite the jet fan array

m2 0 (II) Positive real number

Dist. from upstream Position of the jet fan array (III) mCalculated based on the position of the jet fan array on the drawing sheet (IV)


(I) The interior zone is displayed for information on an orange background and corresponds to the value entered in the fields “Cross-section area” in the “Tunnel sections” and “Ramps” tabs of the “Ramps” command.

(II) The default value does not belong in the area of validity; it must therefore be replaced by a valid value.(III) For a jet fan array located in a tunnel, the upstream distance corresponds to its position in relation to the tunnel’s upstream node.

For a jet fan array located in a ramp, the upstream distance corresponds to its position in relation to the ramp portal for an entrance ramp and in relation to its junction with the tunnel for an exit ramp.

(IV) Once the dialog has been confirmed, the position of the jet fan array is automatically updated on the drawing sheet.

NOTE

To simulate a jet fan array operating in the reverse direction, i.e. in the Downstream - Upstream direction, just enter a negative thrust in the “Unit free-field thrust” field.

Simulation of the control of a reversible jet fan array will require the creation of an array with positive thrust jet fans next to an array with an identical set of jet fans, but with negative thrust. These two arrays are controlled by reducing the operating rate of one array while simultaneously increasing the operating rate of the other array.

► “Injectors” tab


Label Name of the injector - Injector No. i Character string

Injection flow rate Blowing flow rate injected into a tunnel or ramp by the injector m3.s-1 0 Positive real number

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Jet velocity Speed at which air is ejected from the injector outlet m.s-1 0 (I) Positive real number

Angle with tunnel axis

Angle between the tunnel and air jet axes at the injector outlet(II) ° 15 Real number belonging

to ]0;180]

EfficiencyInjector efficiency, in particular, factoring in the effects of the wall and the shape of the blowing device

- 05 Real number belonging to ]0;1]

Tunnel cross-sect. area

Cross-section through the tunnel section or ramp at the level of the injector

m2Cross-section through the tunnel section or ramp at the level of the injector (III)

Non modifiable

Cross-sect. areaat injector

Cross-section through the tunnel section or ramp opposite the injector m2 0 (I) Positive real number

Dist.from upstream (IV)

Distance between the upstream node of the tunnel end or of the ramp and the injector

mCalculated based on the position of the injector in the drawing sheet (V)


(I) The default value does not belong in the area of validity, it must therefore be replaced by a valid value.(II) An angle of between 0° and 90° corresponds to a downstream thrust, and an angle of between 90° and 180° corresponds to an upstream thrust.(III) The interior zone is displayed for information on an orange background and corresponds to the value entered in the “Cross-section area” field in

the “Tunnel sections” and “Ramps” tabs of the “Tunnels / Ramps” command. (IV) For an injector located in a tunnel, the upstream distance corresponds to its position in relation to tunnel’s upstream node.

For an injector located in a ramp, the upstream distance corresponds to its position in relation to the ramp portal for an entrance ramp and in relation to its junction with the tunnel for an exit ramp.

(V) Once the dialog has been confirmed, the position of the injector is automatically updated on the drawing sheet.

► “Blowing vents” tab


Label Name of the blowing vent - Blowing vent No. i Character string

Blown flow rate Blown flow rate in a tunnel or ramp via the blowing vent m3.s-1 0 Positive real number

Distance from upstream (I)

Distance between the upstream node of the tunnel end or of the ramp and the blowing vent

m

Calculated based on the position of the blowing vent in the drawing sheet (II)


(I) For a blowing vent located in the tunnel, the upstream distance corresponds to its position in relation to tunnel’s upstream node.

For a blowing vent located in a ramp, the upstream distance corresponds to its position in relation to the ramp portal for an entrance ramp and in relation to its junction with the tunnel for an exit ramp.

(II) Once the dialog has been confirmed, the position of the blowing vent is automatically updated in the drawing sheet.

► “Extraction dampers” tab


Label Name of the extraction damper - Extraction damper No. i Character string

Extracted flow rate Flow rate extracted from a tunnel or ramp by the extraction damper m3.s-1 0 Real number


Distance between the upstream node tunnel end or of the ramp and the extraction damper

m

Calculated based on the position of the extraction damper on the drawing sheet (II)


(I) For an extraction damper located in a tunnel, the upstream distance corresponds to its position in relation to tunnel’s upstream node.

For an extraction damper located in a ramp, the upstream distance corresponds to its position in relation to the ramp portal for an entrance ramp and in relation to its junction with the tunnel for an exit ramp.

(II) Once the dialog has been confirmed, the position of the extraction damper is automatically updated on the drawing sheet.

► “Massive extraction” tab


Label Name of the massive extraction - Massive extraction No. i Character string

Extracted flow rate Flow rate extracted from a tunnel or ramp by massive extraction m3.s-1 0 Positive real number


Distance between the upstream node tunnel end or of the ramp and the massive extraction

m

Calculated based on the position of the massive extraction on the drawing sheet (II)


41

(I) For a massive extraction located in a tunnel, the upstream distance corresponds to its position in relation to tunnel’s upstream node.

For a massive extraction located in a ramp, the upstream distance corresponds to its position in relation to the ramp portal for an entrance ramp and in relation to its junction with the tunnel for an exit ramp.

(II) Once the dialog has been confirmed, the location of the massive extraction is automatically updated on the drawing sheet.

► “Aeraulic Transparencies” tab


Label Name of the aeraulic transparency - Aeraulic transp. No.i Character string

Transparencycross-area

Section of the aeraulic transparency m2 0 Positive real number

Outside pressure

Relative pressure taken on the external side of the aeraulic transparency in relation to the absolute reference pressure

Pa 0 Real number

Distancefrom upstream (I)

Distance between the upstream node tunnel end or of the ramp and the aeraulic transparency

m

Calculated based on the position of the aeraulic transparency on the drawing sheet (II)


(I) For an aeraulic transparency located in a tunnel, the upstream distance corresponds to its position in relation to tunnel’s upstream node.

For an aeraulic transparency located in a ramp, the upstream distance corresponds to its position in relation to the ramp portal for an entrance ramp and in relation to its junction with the tunnel for an exit ramp.

(II) Once the dialog has been confirmed, the position of the aeraulic transparency is automatically updated on the drawing sheet.

► “Traffic Interruptions” tab


Label Name of the traffic interruption - Traffic interruption No. i Character string

Distancefrom upstream (I)

Distance between the upstream node tunnel end or of the ramp and the traffic interruption

m

Calculated based on the position of the traffic interruption on the drawing sheet (II)


(I) For a traffic interruption located in a tunnel, the upstream distance corresponds to its position in relation to tunnel’s upstream node.

For a traffic interruption located in a ramp, the upstream distance corresponds to its position in relation to the ramp portal for an entrance ramp and in relation to its junction with the tunnel for an exit ramp.

(II) Once the dialog has been confirmed, the position of the traffic interruption is automatically updated on the drawing sheet.

► The button

For air blowing equipment in a tunnel or ramp such as distributed or local blowing vents and injectors, or equipment that is likely to blow air, such as aeraulic transparencies, clicking on the button in the “Pollution” column lets the user open a dialog named “Pollution parameters for: label of the device” and enter the blown air pollutant concentrations for the selected equipment.

Illustration:

The list of pollutants is that defined in the pollutants library that can be accessed via the “Pollutants” command in the “Libraries” menu that automatically contains three gaseous pollutants, carbon monoxide (CO), benzene and nitrogen oxides (NOx), and particulates.

The pollutant concentrations for equipment blown air are automatically zero.Pollutant concentrations can be expressed in mg.m-3 or ppm for gaseous pollutants, and in mg.m-3 or m-1

for opacity, according to the units selected in the application preferences using the “Preferences” command in the “File” menu.

42

NOTE

Pollutant concentrations for equipment blown air in a tunnel or ramp can be entered in two different ways that should not be confused:

either by using the button in the “Devices” dialog

or by using the “Pollution ” command in the “Parameters” menu

The button is used to modify pollutant concentrations for equipment blown air for each separate equipment modelled in the drawing sheet.

The “Pollution” command in the “Parameters” menu is used to modify pollutant concentrations for equipment blown air for all the equipment modelled in the drawing sheet.

► The and buttons

Clicking on the button in the “Control” column opens a dialog entitled “Device control: description of the selected equipment” and is used to enter the control characteristics for the selected equipment.

If several equipment of the same type have been previously grouped using the “Group” command in the “Edit” menu, the button replaces the button. Clicking this button then opens a dialog entitled “Device control: label of the device group” and lets the user enter the joint control characteristics of all the equipment in the selected group.

Illustration of the dialog displayed by clicking on the button:

Illustration of the dialog displayed by clicking on the button:

While the dialoges are identical for a given piece of equipment, whether this is controlled individually or jointly with other equipment of the same type, they differ significantly depending on the type of equipment and, therefore, on the corresponding tab.

For the “Distributed ventilation", “Jet fans", “Injectors", “Blowing vents", “Extraction dampers” and “Massive extractions” tabs:

The dialog is used to specify the operating conditions for an equipment or a group of equipment according to time in relation to full power operation using a coefficient to be entered in the “Multiplying coeff.” fields. This automatically equals 1. All these equipment are therefore operating at full power right from the start of the simulation.

For the “Aeraulic transparencies” tab

The dialog is used to specify the position of the aeraulic transparency, open or closed, according to time. Aeraulic transparencies are automatically closed at the start of the simulation.

43

Illustration:

For the “Traffic interruptions” tab

The dialog is used to specify at which time the traffic is to be interrupted by the closure system, i.e. a barrier or traffic light.

Illustration:

NOTE

No more than one single event may be entered for traffic interruptions. Once the traffic interruption has been activated, it is final.

Traffic interruptions have to be activated after the start of the fire; otherwise, they will have no effect.

All these dialogs contain:

a button for adding an event in equipment control.

Illustration:

a button for modifying the selected event with the mouse in equipment control

a button for deleting the selected event with the mouse in equipment control.

Pressure at portals

This command is used to enter the pressure conditions and pollutant concentrations imposed at the portals of a tunnel and any related ramps; these represent the model’s limit conditions.

44

Illustration:

Once the dialog has been confirmed, the portal pressure conditions are automatically updated in the drawing sheet.






Clicking on the button in the “Pollution” column opens the dialog entitled “Pollution parameters for: label of the imposed pressure condition” and lets the user enter the pollutant concentrations for the air likely to enter the tunnel via the selected portal.

Illustration:

The list of pollutants is that defined in the pollutants library and can be accessed via the “Pollutants” command in the “Libraries” menu that automatically contains three gaseous pollutants, carbon monoxide (CO), benzene and nitrogen oxides (NOx), and particulates.

Pollutant concentrations for air entering the tunnel via a portal are automatically zero.

Pollutant concentrations can be expressed in mg.m-3 or ppm for gaseous pollutants, and in mg.m-3 or m-1

for opacity, depending on the units selected in the application preferences using the “Preferences” command in the “File” menu.

45

NOTE

Pollutant concentrations in air that are likely to enter a tunnel or ramp via a portal can be entered in two different ways that should not be confused:

either using the button of the “Devices” dialog

or using the “Pollution” command in the “Parameters” menu

The button is used to modify, for each individual portal, the pollutant concentrations for air likely to enter the tunnel via a given portal.

The “Pollution” command in the “Parameters” menu is used to modify, for all the portals, the pollutant concentrations for air likely to enter the tunnel via these portals.

Fire

This command is used to define the fire to be studied in “Fire mode” via a dialog for the selected scenario.

This command is only activated if a fire is modelled in the drawing sheet.

The parameters to be entered are:

start time of the fire

location of the fire in relation to the upstream node of the ramp or tunnel end

type of fire

The fire always starts at t = 00 h 00 min 00 s; its position is calculated automatically based on its location in the drawing sheet.

The CAMATT 2.20 release automatically contains the fire load curves for the 12 reference fires defined in leaflet 4 of the guide to road tunnel safety dossiers relating to Specific Hazards Studies, in addition to opacity flows and emission rates for the related pollutants. The mouse can be used to select one of these reference fires by checking the element located in the “Choose” column.

Illustration:

The pollutant automatically taken into account for each of these reference fires is carbon monoxide (CO); however, another pollutant may be taken into account by changing the value of the pollutant emission rate.

The dialog also contains:

a button for adding a fire by defining the fire heat release rate curve, its opacity flux and pollutant emission rate via a dialog.

46

Illustration:

This dialog contains:▪ a field for entering the type of fire.▪ a button for adding an event to the fire evolution and defining the fire heat release

rate curve, its opacity flux and pollutant emission rate at a given moment in time.

Illustration:

The event time needs to be defined in relation to the fire start time; this is a relative rather than an absolute time.The heat release rate figure to be recorded is the fire’s total heat release rate, a third of which is assumed to be dissipated via radiation through the walls directly opposite the fire. Therefore, only two thirds of the recorded heat release rate is used in the calculations.

▪ a button for modifying the selected event using the mouse.▪ a button for deleting the selected event using the mouse.

a button for changing the fire selected and highlighted in blue with the mouse via a dialog identical to that described above that lets the user add a fire.

a button used to delete the fire selected and highlighted in blue with the mouse.

NOTE

All the fires listed in the “Fire” dialog make up a library in the same way as those found for wall materials or pollutants in the “Libraries” menu.

As with the two others, this library is:

common to all the scenarios

saved in the bdd.xml file of the .camatt/bdd folder found in the user profile folder in Windows or in the $HOME folder in Linux, and therefore specific to each user.

All changes or additions to this library will therefore apply to all the scenarios, whether they are new, existing or duplicated, but will only be valid for the user responsible for said change or addition.

Pollution

Pollutant concentrations for the air around portals and the air injected into the tunnel or its ramps are always zero.

As described earlier in pages 46 and 47 of this User's Guide, clicking on the button lets the user modify this value individually for each portal or each equipment injecting air into the tunnel or its ramps, if any.

The “Pollution” command is used to overwrite all these values and to assign to all the equipment modelled

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in the drawing sheet and to all the portals of the tunnel and its ramps, if any, the same pollutant concentrations for equipment blown air or for air likely to enter the tunnel via one of its portals.

Illustration:

The list of pollutants is that defined in the pollutants library that can be accessed using the “Pollutants” command in the “Libraries” menu that automatically contains three gaseous pollutants, carbon monoxide (CO), benzene and nitrogen oxides (NOx), and particulates.

Pollutant concentrations in ambient air are automatically zero.

Pollutant concentrations can be expressed in mg.m-3 or in ppm for gaseous pollutants, and in mg.m-3 or m-1 pour opacity, depending on the units selected in the application preferences via the “Preferences” command in the “File” menu.

To assign the same concentration for a given pollutant to all the portals and all the equipment modelled in the drawing sheet, just enter the new value to be taken account of for the selected pollutant and click on the relevant button found in the “Apply to all” column, then quit the dialog by clicking on the

button.

NOTE

The “Pollution” command in the “Parameters” menu only acts on air blowing equipment already modelled in the drawing sheet; it has no effect on any equipment that is modelled in the drawing sheet at a later date. For such equipment, the pollutant concentrations for injected air remain the default value, i.e. zero.

Traffic

This command is used to characterise road traffic for the selected scenario.

The following table describes the fields to be filled in, their default value and their area of validity:


Proportion of HGVs Proportion of HGVs in the traffic - 0 Real number belonging to [0;100]

Sigma_CX for cars Frontal surface for cars m2 0,9 Positive real number

Sigma_CX for HGVs Frontal surface for HGVs m2 4,5 Positive real number

Distance between stopped vehicles

Front bumper - front bumper distance for stopped vehicles m 10 Positive real number

Pollutant emissions

Vehicle pollutant emissions for each tunnel section and ramp, for each pollutant listed in the pollutants library

kg.s-1.m-1 0 Positive real number

Nominal speed Traffic speed in each traffic direction km.h-1 70 Positive real number

Nominal flux Vehicle flux in each traffic direction(I) veh.h-1 0 Positive real number

Number of lanes per direction

Number of lanes in each traffic direction for each tunnel section and ramp (II)

- 1 Positive whole number

(I) Where there are one or more ramps, the only fluxes to be recorded are those for vehicles entering each end of the marked tunnel in relation to the direction of traffic, the vehicles entering via the entrance ramps, and leaving via the exit ramps. The traffic flux in the other tunnel sections is automatically calculated by the application by conservation of the traffic at tunnel - ramp junctions.

(II) For two-way traffic, the number of driving lanes is supposed to be the same in each traffic direction.

48

Illustration:

Environment

This command is used to characterise the tunnel environment, together with heat transfers with tunnel walls and ramps, if any, for the selected scenario.

The following table describes the fields to be filled in in order to characterise the tunnel environment, together with their default value and area of validity:


Average altitude Average tunnel altitude m 0 Positive real number

Ambient air temperature

Mean temperature of ambient air inside the tunnel (I) m2 0.9 Real number

(I) This temperature applies to ambient air inside the tunnel or ramp, as well as outside and to a depth of 16 cm in the walls .

Ambient air density is calculated automatically based on the values entered for these two fields according to the following equation:

avec

o : density of ambient airPo : absolute pressure at sea level, i.e. 101 325 PaT o : temperature of ambient air inside the tunnelzalt : average tunnel altitude

The following table describes the fields to be filled in in order to characterise heat transfers with tunnel walls and any ramps, together with their default value and area of validity:


Min value of radiant heat transfer cœff.

Coefficient for the minimum radiant heat transfer between smoke and tunnel walls and any ramps

W.m-2.K-1 0 Positive real number

Max value of radiant heat transfer cœff.

Coefficient for the maximum radiant heat transfer between smoke and tunnel walls and any ramps

W.m-2.K-1 100 Positive real number

49

o=3,485 .10−3 .Po

To

.10−

273.zalt

18400.T o


Wall emissivity Wall emissivity used to calculate the radiant heat transfer coefficient - 0.9 Positive real number

View factor

View factor for the tunnel and ramps characterising their shape and used to calculate the radiant heat transfer coefficient

- 1 Real number belonging to the interval ]0;1]

Data summary

This command is used to export all the data for the selected scenario into a *.csv file.

This file takes the name “nomScenario_Recap.csv” and is saved in the “Export” folder specified in the application preferences via the “Preferences” command in the “File” menu.

A message is displayed to notify the user that the export has been completed.

Illustration:

The file generated can be opened using a text editor such as Excel or Open Office.

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2.2.5 “Simulation” menu

The “Simulation” menu in the menu bar is used to launch the calculation for the selected scenario in either smoke extraction mode or normal extraction mode.

Illustration:

On opening a new drawing sheet, all the commands are shaded.

They remain shaded and inaccessible until the user has correctly entered all the model data required for the calculations.

Fire mode

This command is used to launch the calculation for the selected scenario in “Fire mode” using a dialog to specify:

the simulation’s ending time

the simulation’s time step

The simulation’s starting time set at 00 h 00 min 00 s cannot be changed, which means that the simulation ending time also corresponds to the duration of the simulation. This is automatically set at 30 minutes.

The simulation’s time step is used to define the calculation’s results sampling. This corresponds to the time step between 2 results curves f(t) at successive fixed x. They must not be confused with the calculation’s time step, which is set at 1 s in the code, and that may not be changed by the user.

Illustration:

Clicking on the button executes the calculation in “Fire mode".

NOTE

Before executing calculations in “Fire mode", the application automatically checks for the presence of any co-located model elements. If they are found, the calculation is not executed and the user is alerted to the presence of co-located elements. The user then has to move the relevant model element(s) to ensure there are no longer any co-located elements.

Pollution mode

This command is used to launch the calculation in “Pollution mode” for the selected scenario.

The calculation is made under steady state regime.

A message is displayed to notify the user that the calculation has been completed.

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Illustration:

NOTE

As described for the “Fire mode” command, the application automatically checks for the presence of any co-located model elements before executing the calculation.

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2.2.6 “Results” menu

The “Results” menu in the menu bar is used to view the results of the calculation executed in either “Fire mode” or “Pollution mode", and of the export in a *.csv file.

If the latest calculation was executed in “Fire mode", then this menu is also used to view traffic distribution according to time in the tunnel and its ramps, if any, and to export the data for a given time to a *.csv file.

Illustration:

On opening a new drawing sheet, all the commands are shaded.

They remain shaded and inaccessible until the user has executed a calculation in either “Pollution mode” or “Fire mode".

Executing a calculation activates some or all of the commands in this menu depending on whether the calculation was executed in “Fire mode” or “Pollution mode”:

Illustration of a calculation in “Fire mode” with a modelled fire:

Illustration of a calculation in “Fire mode” with no modelled fire or in “Pollution mode”:

Plot results

This command is used to view plot results for the latest calculation executed in either “Fire mode” or “Pollution mode", via a dialog.

The mouse is used to click in the dialog to select:

the part of the tunnel for which the user wishes to view the results: tunnel or ramp

the physical quantities to be displayed from among all the available physical quantities

In “Fire mode", the available quantities are:▪ air temperature▪ wall temperature▪ air opacity▪ pollutant concentration▪ air velocity▪ longitudinal flow rate ▪ total pressure▪ static pressure

In “Pollution mode", the available quantities are:▪ pollutant concentration for all the pollutants listed in the pollutants library, accessible and

modifiable using the “Pollutants” command in the “Libraries” menu▪ air velocity▪ longitudinal flow rate

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the type of view for the physical quantities selected for display

In “Fire mode", a physical quantity can be viewed as:▪ either a spatial curve, f(x), for a given time▪ or a time curve, f(t), for a given abscissa▪ or contour lines in the plane (x,t) i.e. f(x,t)

In “Pollution mode", as the calculation is made in steady state regime, a physical quantity can only be viewed as a spatial curve, f(x).

according to the type of display selected:▪ either, the times for which the user wishes to view the spatial curve f(x) for one or more of the

selected physical quantities▪ i.e. the abscissas for which the user wishes to view the time curve, f(t) for one or more of the

selected physical quantities

Illustration in “Fire mode”: Illustration in “Pollution mode”:

To select several physical quantities or several times or abscissas, just click on them using the mouse while pressing the Ctrl or Maj key.

The actions described in the first three points above can be performed in any order. On the other hand, the action described in the last point can only be performed after having selected the type of display for the selected physical quantities.

NOTE

The contour lines f(x,t) are only available for:

air temperature

air opacity

pollutant concentration

air velocity

► Curves f(x) and f(t)

Each physical quantity is viewed in a window whose name indicates the type of display, the name of the scenario and the part of the tunnel under study.

The name of the physical quantity is displayed as the title of the f(x) or f(t) curve.

If the user has chosen to view the evolution of a given quantity in terms of f(t) for several abscissa or f(x) at several moments in time, all the curves are displayed on the same graph.

54

Illustration:

A right-click on the chart drawing sheet used to view the evolution of a physical quantity lets the user:

access and modify chart properties

save the chart in *.png format

print the charts

access zoom and automatic scaling functionalities

Illustration:

Chart properties can be used, in particular, to change the chart’s title and scales.

Illustration:

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right click

► Contour lines f(x,t)

Each physical quantity is displayed in a window w whose name indicates the type de display, the name of the scenario and the part of the tunnel under study.

The name of the physical quantity being viewed is displayed as the title of the contour line curve f(x,t).

Illustration:

As with the f(x) and f(t) curves, a right-click on the chart’s drawing sheet lets the user:

access and modify chart properties

save the chart in *.png format

print the charts

access automatic scaling and zoom functionalities

Illustration:

The chart’s colour scale is displayed on the right of the curve. It can be modified by double-clicking on the colour scale that starts an editor.

Illustration:

56

clicdroit

right click

dou ble-click

Illustration:

This is used to match the chosen colours to the selected values (represented by the horizontal arrows). Colours are interpolated between two arrows.

To add new values, just left-click in the desired area of the colour bar.

To delete an arrow, just select it and click on the Suppr key.

The arrows can also be moved using the mouse.

To select the colour linked to a value (or accurately specify the value corresponding to the arrow), just double-click on the desired arrow.

An editor lets the user specify the value corresponding to the colour in the “Value” field together with the corresponding colour. This can be selected from a list of basic colours, in TSL format (Hue, Saturation, Brightness) or RVB (Red, Green, Blue).

Illustration:

► Viewing out-of-service jet fans

The evolution curves f(x) and f(t) can be used to display jet fan arrays qui that have been disabled due to an excessive temperature rise in a tunnel or ramp.

You can do this simply by indicating it in the application preferences accessible via the “Preferences” command in the “File” menu by checking the “Display out-of-service jet fans” box.

57

Illustration:

The location of each heat-disabled jet fan array is marked on the f(x) evolution curves by an annotation that gives the name of the disabled jet fan array and the time of its disablement.

Only jet fan arrays that were disabled at the selected time are notified on the f(x) evolution curve.

Illustration:

On the f(t) evolution curves, each time when a jet fan array was disabled by the heat is marked by an annotation that gives the name of the array disabled at this time.

Illustration:

Show traffic

This command is used to view the traffic distribution in each traffic direction, according to time, in the tunnel and any related ramps for the selected scenario.

The traffic distribution display window contains:

a button used to read traffic distribution according to time

58

a button used to stop reading traffic distribution according to time

a button used to view traffic distribution 1 s before the start of the fire

a button used to view traffic distribution at the end of the simulation

Traffic distribution is viewed on a diagram representing the modelled tunnel along with any related ramps, and on which are marked:

in green, zones where vehicles are moving normally

in red, zones where vehicles are stopped

in grey, zones free of vehicles

Illustration:

NOTE

The total number of stopped vehicles is given between brackets in the key.

Export results

This command is used to export, via a dialog, the results of the last calculation executed in “Fire mode” or “Pollution mode” as a *.csv file.

Use the mouse to select the following elements in the dialog:

the part of the tunnel for which the user wishes to export the results: tunnel or ramp

the physical quantity(ies) to be exported from among all the physical quantities available

In “Fire mode", the quantities available are:▪ air temperature▪ wall temperature▪ air opacity▪ pollutant concentration▪ air velocity▪ longitudinal flow rate ▪ total pressure▪ static pressure

In “Pollution mode", the quantities available are:▪ pollutant concentration for all the pollutants listed in the pollutants library, that can be

accessed and modified using the “Pollutants” command in the “Libraries” menu ▪ air velocity▪ longitudinal flow rate

59

the type of values to be exported

In “Fire mode", you can export:▪ either, an table, f(x), listing the value of the physical quantity(ies) selected according to the

abscissa of a given time▪ or, a table, f(t), listing the value of the physical quantity(ies) selected according to the abscissa

of a given time▪ or, a double-entry table, f(x,t), listing the value of the physical quantity(ies) selected according

to the abscissa of a given time

In “Pollution mode", as the calculation is made in steady state regime, it is only possible to export a table, f(x), listing the value of the physical quantity(ies) selected according to the abscissa of a given time.

according to the type of selected value to be exported:▪ either the time(s) for which the user wishes to export an f(x) table for the physical quantity(ies)

selected▪ or the abscissa(es) for which the user wishes to export an f(t) table for the physical

quantity(ies) selected

Illustration in “Fire mode”: Illustration in “Pollution mode”:

To select several physical quantities or several times or abscissae, just select them with the mouse while pressing the Ctrl or Maj key.

The actions described in the first three points above can be performed in any order. On the other hand, the action described in the last point can only be performed after having selected the type of values to be exported.

NOTE

The option of exporting a double-entry table f(x,t) is only available for:

air temperature

air opacity

pollutant concentration

air velocity

Once all the elements have been selected, clicking on the button starts the export and generates a *.csv file containing all the requested elements.


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Illustration:

The file generated is given the name “nomScenario_typeSimu_typeExport.csv” where:

nomScenario is the name of the selected scenario

typeSimu is the type of simulation performed▪ Fire mode▪ Pollution mode

typeExport is the type of export▪ T - according to time▪ X - according to abscissa▪ XT - according to time and abscissa

The generated file can be opened using a text editor such as Excel or Open Office.

Export traffic results

This command is used to export to a *.csv file, via a dialog, the distribution of vehicles in the tunnel and any related ramps at a given moment in time.

Illustration:

This file is given the name “nomScenario_ResultatsTrafic.csv” and is saved in the “Export” folder specified in application preferences using the “Preferences” command in the “File” menu.


Illustration:

The generated file can be opened using a text editor such as Excel or Open Office.

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2.2.7 “Libraries” menu

The “Libraries” element in the menu bar is used to access libraries for wall materials and pollutants.

Illustration:

Wall materials

This command uses a dialog to list and parameter the materials that can be used for tunnel walls and any related ramps. This wall materials library is common to all the scenarios.

Wall materials are chosen from the drop-down list accessed via the “Material type1” and “Material type 2” fields found in the “Tunnel sections” and “Ramps” tabs in the “Tunnel / Ramps” window in the “Parameters” menu.

The wall materials library automatically contains the concrete and fire protection generally used in tunnels to improve the structure’s fire resistance. It also contains the values generally selected for the physical properties required to evaluate heat transfers with walls, i.e. their density, thermal conductivity3 and their specific heat capacity4.

Illustration:

The dialog also contains:

a button for adding a material via a dialog used to define its name, density, thermal conductivity and specific heat capacity.

Illustration:

a button used to modify the material selected and highlighted in blue with the mouse, using a dialog identical to that described above used to add a wall material.

a button used to delete the material selected and highlighted in blue with the mouse.

A message is displayed asking the user whether they wish to delete the material from the wall materials library.

3 Reflects the conductive heat transfer generated by the molecular vibration of the material.4 Represents the amount of energy required to raise the temperature of 1 kilogram of the material by one degree Kelvin.

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Illustration:

NOTE

As with the fires library that can be accessed using the “Fire” command in the “Parameters” menu and with the pollutants library, this library is:

common to all scenarios

saved in the bdd.xml file in the .camatt/bdd folder found in the user profile folder in Windows, or in the $HOME folder in Linux, and is therefore specific to each user

All modifications or additions to this library will therefore apply to all scenarios, whether new, existing or duplicated, but will only be valid for the user that made the modification or addition.

Pollutants

This command uses a dialog to list and parameter the pollutants to be studied for simulations in “Pollution mode". This pollutants library is common to all scenarios.

The list of pollutants defined in this library forms the list of accessible pollutants:

using the button found in the various dialoges used to modify pollutant concentrations in blown air generated by an equipment or by one of the portals

using the “Pollution” command in the “Parameters” menu, which is used to modify pollutant concentrations in blown air generated by all the equipment modelled in the drawing sheet and by all the portals

The dialog contains:

a section on gaseous pollution that automatically contains three pollutants:▪ carbon monoxide (CO)▪ benzene▪ nitrogen oxides (NOx)

This section also contains the molar masses of these three pollutants based on which the concentration can be expressed either in mg.m-3, or in ppm depending on the unit selected in the application preferences via the “Preferences” command in the “File” menu. You can switch from concentrations in ppm to concentrations in mg.m-3 as follows:

Cmg.m−3 =Mmolaire

VmolaireCppm

avec

Vmolaire = 24,453 l.mol−1 5

a section on particulate pollution that automatically contains the particulates class for which an air opacity of 1 m-1 corresponds to an airborne particulate concentration of 100 mg.m -3, the value suggested in CETU’s “Ventilation pilot dossier”.

5 Molar volume of air, assumed to be an ideal gas at 20°C and 1 atm.

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Illustration:

For each of these two sections, the dialog also contains:

a button for adding a gaseous pollutant or particulates class via a dialog used to defined:▪ for gaseous pollutants, their name and molar mass▪ for the particulates class, their name and the conversion factor to be applied in order to switch

from an air opacity of 1 m-1 to a particulates concentration expressed in mg.m-3

Illustration of the addition of a gaseous pollutant:

Illustration of the addition of a particulates class:

a button for modifying the gaseous pollutant or particulates class selected and highlighted in blue with the mouse via a dialog identical to that described above used to add a gaseous pollutant or particulates class.

a button for deleting the gaseous pollutant or particulates class selected and highlighted in blue with the mouse.

A message is displayed asking the user whether they wish to delete the material from the wall materials library.

Illustration:

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NOTE

As with the fires library that can be accessed using the “Fire” command in the “Parameters” menu and with the wall materials library, this library is:

common to all scenarios

saved in the bdd.xml file in the .camatt/bdd folder found in the user profile folder in Windows, or in the $HOME folder in Linux, and is therefore specific to each user

All modifications or additions to this library will therefore apply to all scenarios, whether new, existing or duplicated, but will only be valid for the user that made the modification or addition.

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2.2.8 “?” menu

The “?” menu in the menu bar is used to access information on the application and on the current User Guide to the CAMATT 2.20 release.

Illustration:

Help…

This command provides online access to the current User Guide to the CAMATT 2.20 release in *.pdf format.

This command can also be accessed by pressing the keyboard’s F1 key..

About…

This command is used to access information on the application version and the Copyright.

Illustration:

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2.3 ToolbarThe toolbar contains icons that provide rapid access to the main application commands.

Illustration:

The list of these icons can be parametered using the “Preferences" command in the “File” menu when selecting which icons to display and which to mask. This list can contain at the most the 38 icons shown below.

Illustration:

The following table describes the commands that can be accessed via the 38 icons automatically contained in the toolbar:

Icon Menu Command

File New

File Open

File Save

File Save as

File Duplicate

File Print preview

File Print

Edit Undo

Edit Redo

Edit Delete

Edit Selection Mode

Edit Zoom in

Edit Zoom out

Edit Zoom box

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Icon Menu Command

Edit View all

Edit Move

Edit Grid

Edit Group devices

Edit Ungroup devices

Network Tunnel

Network Ramp

Network Jet fan array

Network Injector

Network Blowing vent

Network Extraction damper

Network Massive extraction

Network Local head loss

Network Aeraulic transparency

Network Traffic interruption

Network Fire

Parameters Tunnel / Ramps

Parameters Devices

Parameters Pressure at portals

Simulation Fire mode

Simulation Pollution mode

Results Plot results

Results Show traffic

Results Export results

Icons remain shaded so long as the related command is inactive.

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2.4 Drawing sheetThe drawing sheet is used to model the tunnel, any related ramps, its equipment and, where applicable a fire, specific to the selected scenario.

In addition to the drawing area, the drawing sheet also contains:

a banner

a key

a scale

Illustration:

2.4.1 Drawing area

The drawing area is the part of the drawing sheet in which are modelled the tunnels, any related ramps, equipment and, where applicable, fires.

This modelling is performed using the commands in the “Network” and “Edit” menus as follows:

1) Select the “Tunnel” command in the “Network” menu and insert all the tunnel sections modelled in the drawing sheet (see pages 18 to 23)

2) If the tunnel has a ramp, select the “Ramp” command in the “Network” menu and insert all the tunnel ramps in the drawing sheet (see pages 22 to 25)

3) Select the type of equipment to be modelled using the related command in the “Network” menu and insert all equipment of this type in the drawing sheet (see pages 24 to 34)

4) Insert all the other equipment in the drawing sheet following the instructions in points 3)

5) Where applicable, select equipment of the same type that will have joint control by pressing the Ctrl key; group the equipment using the “Group devices” command in the “Edit” menu (see page 17)

6) For a simulation in “Fire mode", select the “Fire” command in the “Network” menu

7) Where applicable, insert the fire in the drawing sheet (see page 32)

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Banner

LegendScale

Drawing area

Once the tunnel and any related ramps, plus its equipment and, where applicable, a fire, have been modelled in the drawing sheet, all the model data can be entered using the commands in the “Parameters” menu.

The tunnel and any related ramps are modelled in plan view; this makes it easy to view the angle between the tunnel and the ramps.

2.4.2 Banner

The banner located at the top of the drawing sheet is used to display or mask certain data in the drawing area using checkboxes:

ramp angles

slopes of tunnel sections

tunnel orientation

devices

Ramp angle

Depending on whether the box is checked or not, this command is used to display or mask the acute angle between all the ramps shown in the drawing area and the tunnel.

Illustration:

Slopes of tunnel sections

Depending on whether the box is checked or not, this command is used to display or mask the slopes for all tunnel sections and ramps shown in the drawing area.

Illustration:

Tunnel orientation

Depending on whether the box is checked or not, this command is used to display or mask the orientation of all tunnel sections and ramps shown in the drawing area that provides a reference for the positioning of equipment or fires.

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Illustration:

Devices

Depending on whether the box is checked or not, this command is used to display or mask a ll the equipment shown in the drawing area that provides a reference for the positioning of equipment or fires.

Illustration:

2.4.3 Legend

When building the model in the drawing area, a legend is displayed at the bottom right of the drawing sheet and is automatically updated according to the elements modelled (tunnel, ramp, equipment and fire).

Illustration:

The legend is automatically displayed in the drawing sheet. However, users can mask the key using the “Preferences” command in the “File” menu if they wish.

2.4.4 Scale

To facilitate the modelling process, a scale is displayed at the bottom of the drawing sheet; five grid squares automatically correspond to 200 m.

This scale is then updated automatically according to the zoom selected using the related commands in the “Edit” menu.

The scale is automatically displayed in the drawing sheet. However, users can mask the scale using the “Preferences” command in the “File” menu if they wish.

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3 SOLVED EQUATIONSThe CAMATT 2.20 release solves the following physical equations governing flow:

the equation expressing the conservation of mass

the equation expressing the conservation of the momentum in the main direction of flow

the equation expressing the conservation of enthalpy

thermodynamic equations

To these equations can be added those that govern the transport of a passive scalar in the flow used to identify a pollutant concentration in the tunnel at any moment in time.

3.1 Conservation of massThe equation expressing the conservation of mass is:

∂ρ∂ t

∂ ρu∂x

=Sm

whereρ : air density [kg.m-3]u : air velocity [m.s-1]S m : mass source (sink) [kg.s-1.m-3]t : time [s]x : curvilinear abscissa along the length of the tunnel [m]

The source term (or sink) of the mass S m represents the mass flow blown into or extracted from the tunnel or its ramps, if any, per unit of volume.

CAMATT is used to factor in linear and local source terms (or sinks) for mass.

CAMATT calculates mass sources based on:

ambient air density

distributed blowing flow rate imposed on a section or ramp

flow rate imposed for blowing vents and injectors

pressure imposed outside aeraulic transparencies and their section when the difference between this pressure and that in the tunnel is positive

CAMATT calculates mass sinks based on:

ambient air density for the distributed extractions and extraction dampers

air density in the tunnel for massive extractions and aeraulic transparencies

distributed extraction flow rate imposed on a section or ramp

flow rate imposed for extraction dampers and massive extractions

pressure imposed outside aeraulic transparencies and their section when the difference between this pressure and that in the tunnel is negative

3.2 Conservation of the momentumCAMATT solves the equation expressing conservation of the momentum in the direction of flow as follows:

∂ ρu∂ t

∂ρu²∂x

=−∂Ps

∂xSmvt

whereρ : air density [kg.m-3]u : air velocity [m.s-1]Ps : static air pressure [Pa]S mvt : source (or sink) for the momentum [kg.m-2.s-2 ]t : time [s]

72

x : curvilinear abscissa along the length of the tunnel [m]

The momentum source term (or sink) Smvt represents the variation over time of the momentum of air per unit of volume due to the action of:

buoyancy forces due to the buoyancy acting on hot smoke

drag (air friction) forces acting on tunnel walls

vehicle forces acting on the air

driving forces communicated to the air by jet fan arrays

driving forces communicated to the air by injectors

forces due to air drag in zones of turbulence created opposite singularities (change of section, obstacles, etc.)

The momentum source term (or sink) S mvt can therefore be described as:

Smvt=∆ Pche∆ Pfrot∆ Ppist∆ Pacc∆ Pinj∆ Psing

where∆Pche : variation over time of the momentum per unit of volume

due to buoyancy forces [kg.m-2.s-2 ]∆Pfrot : variation over time of the momentum per unit of volume due to drag (air friction) on the tunnel walls [kg.m-2.s-2 ]∆Ppist : variation over time of the momentum per unit of volume due to forces exerted by vehicles on air [kg.m-2.s-2 ]∆Pacc : variation over time of the momentum per unit of volume due to driving forces communicated to the air by jet fan arrays [kg.m-2.s-2 ]∆Pinj : variation over time of the momentum per unit of volume due to driving forces communicated to the by injectors [kg.m-2.s-2 ]∆Psing : variation over time of the momentum per unit of volume due to drag (air friction) on zones of air turbulence [kg.m-2.s-2 ]

CAMATT is used to factor in these momentum source terms (or sinks), which can be broken down into two categories:

linear source terms (or sinks) (∆Pche, ∆Pfrot and ∆ppist)

local source terms (or sinks) (∆Pacc, ∆Pinj and ∆psing)

Local momentum source terms (or sinks) physically represent a greater number of local variations in pressure (kg.m-1.s-2) than variations in momentum per unit of volume (kg.m-2.s-2), i.e. variations in pressure per unit of length.

However, a local pressure variation may be equated to a variation in pressure per unit of length by introducing the function:

χεξ = {1ε

si ξ ∈ [− 12ε

; 12ε

]

0

Assuming that a variation in pressure ∆Pp in xp is, not local, but distributed along a length εL where ε ≪ 1 and L the length of a tunnel section or ramp, it can be equated to a variation in pressure per unit of length ∆Pr

where:

∆ Pr=∆ Pp

Lχε

x−xp

L

Tending ε towards 0, the final equation can be written as:

∆ Pr=∆ Pp

Lδ

x−xp

L

whereδ : Dirac’s function6

6 Defined by f ∈ C(ℝ), ∫−∞

∞δx f x=f 0

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3.2.1 Linear source terms (or sinks)

Buoyancy forces

Buoyancy forces induce a variation over time of the momentum of air per unit of volume (∆Pche) that can be expressed as:

∆ Pch=−α ρ−ρog [kg.m-2.s-2]

whereα : slope of the tunnel section or ramp [-]ρ : air density [kg.m-3]ρo : ambient air density [kg.m-3]g : acceleration due to gravity (= 9.81) [m.s-2]

Drag (air friction) forces on tunnel walls

For each tunnel section or ramp, the air friction forces on the walls induce a variation over time of the momentum of air per unit of volume (∆Pfrot) that can be expressed as:

∆ Pfr=−λ Π4S

ρu∣u∣2

[kg.m-2.s-2]

whereλ : Moody friction coefficient [-]ρ : air density [kg.m-3]u : air velocity [m.s-1]S : cross-section through the tunnel section or ramp [m2]Π : perimeter of the cross-section through the tunnel section or ramp [m]

Vehicle forces on the air

For each tunnel section and ramp, the forces exerted by vehicles on air induce a variation over time of the momentum of air per unit of volume (∆Ppist) that can be expressed as:

∆ Ppist=n1−pCx VLΣVLpCx PLΣPL

Sρ u−v ∣u−v∣ [kg.m-2.s-2]

wheren : number of vehicles per linear metre in the tunnel section or ramp [veh.m-1]p : percentage of HGVs in the traffic [-]Cx VL : drag coefficient for passenger vehicles [veh-1]Σ VL : average frontal surface for passenger vehicles [m2]Cx PL : drag coefficient for HGVs [veh-1]Σ PL : average frontal surface for HGVs [m2]ρ : air density [kg.m-3]u : air velocity [m.s-1]v : vehicle speed in the tunnel section or ramp [m.s-1]S : cross-section through the tunnel section or ramp [m2]

CAMATT calculates the number of vehicles per linear metre n for each tunnel section or ramp based on:

hourly throughput of vehicles in the tunnel section or ramp

vehicle speed in the tunnel section or ramp

inter-distance of stopped vehicles

CAMATT distinguishes two situations in order to determine traffic distribution in each tunnel section or ramp:

► Presence of a fire or a single traffic interruption

Where there is a single traffic interruption element or fire in a tunnel section or ramp, CAMATT breaks down this section or ramp into four zones per direction of traffic.

74

Illustration for a fire:

wherexi : position of the fire [m]L : length of the tunnel section or ramp [m]

Vehicles are circulating normally in zones 1 and 4, and are stopped in zone 2. Zone 3 is free of vehicles.

The boundary between zones 1 and 2 varies over time as the traffic jam cause by a fire or traffic interruption element extends at a speed C that is calculated using the equation:

C= Q1000

Io

n−Qv

[km.h-1]

whereQ : hourly throughput of vehicles in the tunnel section or ramp [veh.h-1]v : vehicle speed in the tunnel section or ramp [km.h-1]n : number of lanes in the tunnel section or ramp [-]Io : inter-distance between stopped vehicles [m]

The boundary between zones 3 and 4 also varies over time as the presence of a fire or traffic interruption element prevents vehicles from overtaking and creates a vehicle-free zone, zone 3, which extends at the speed v of vehicles in the tunnel section or ramp.

When one of these boundaries reaches the end of a section, it diffuses into the adjacent section(s) with a new speed C* or v* recalculated based on the traffic data specific to each section.

► Presence of a fire and a traffic interruption or of several traffic interruptions

Where there is a fire and one or two traffic interruption(s) in a tunnel section or ramp, CAMATT breaks down this section or ramp into seven zones per direction of traffic. At each new traffic interruption, three additional zones are added.

Illustration:

wherexi : location of the fire [m]xb : location of the traffic interruption [m]L : length of the tunnel section or ramp [m]

Clearly, zones A, B and C can only exist if the traffic interruption is activated sufficiently early. For example, in the illustration above, the condition to be complied with is:

xi−xbCt b− ti

60

whereti : start of the fire [min]tb : time of activation of the traffic interruption [min]C : speed of the tailback in the tunnel section or ramp [km.h-1]

The boundaries between zones A and B on the one hand, and zones D and E on the other hand, vary over time as the traffic jam caused by a fire or traffic interruption element extends at a speed C.

The boundaries between zones C and D on the one hand, and zones F and G on the other hand, also vary over time as a fire or traffic interruption element prevents the vehicles from overtaking and creates vehicle-free zones, zones C and F, that extend at the speed v of vehicles in the tunnel section or ramp.

75

firexi

L

zone 1 zone 2 zone 3 zone 4

speed of tailback C

firexi

L

zone C zone E zone F zone G

speed of tailback Cspeed of tailback C

trafficinterru ption

xb

zone A zone B zone D

When one of the boundaries between zones A and B or between zones F and G reaches the end of a section, it diffuses into the adjacent section(s) with a new speed C* or v* recalculated based on the traffic data specific to each section.

3.2.2 Local source terms (or sinks)

Driving forces communicated to the air by a jet fan array

The driving forces of air communicated by a jet fan array induce a variation over time of the momentum of air per unit of volume (∆P acc) that can be expressed as:

∆ P acc=na kaF rρρ r

1− uua

1Sa L

δ x−xa

L [kg.m-2.s-2]

wherena : number of jet fans making up the array [-]ka : efficiency coefficient of a jet fan [-]Fr : free-field thrust of a jet fan at the reference temperature [kg.m.s-2]ρ : air density opposite the jet fan array [kg.m-3]ρ r : reference density linked to Fo [kg.m-3]u : air velocity opposite the jet fan array [m.s-1]ua : jet fan blowing speed [m.s-1]Sa : tunnel section or ramp opposite the jet fan array [m2]L : length of the tunnel section or ramp [m]δ : Dirac’s functionxa : abscissa of the jet fan array [m]

Driving forces communicated to the air by an injector

The driving forces of air communicated by an injector induce a variation over time of the momentum of air per unit of volume (P inj) that can be expressed as:

∆ P inj=kinj ρo Qv injvinj cosα inj−u 1Sinj L

δ x−xinj

L [kg.m-2.s-2]

wherekinj : efficiency coefficient of the injector [-]ρo : ambient air density [kg.m-3]Qv inj : injector flow rate [m.s-3]vinj : injector blowing speed [m.s-1]αinj : angle of the injector jet in relation to the tunnel axis [rad]u : air velocity directly opposite the injector [m.s-1]Sinj : tunnel section or ramp directly opposite the injector [m2]L : length of the tunnel section or ramp [m]δ : Dirac’s functionxinj : abscissa of the injector [m]

Forces due to air drag in turbulence zones

Each change of section (portal, jet fan niche, modification of transverse profile) and each obstacle found in the tunnel or ramp (traffic sign) cause airflow turbulences. Each of these singularities induces a variation over time of the momentum of air per unit of volume (∆P sing), which can be expressed as:

∆ Psing=−ρs

2ξs

Qvs2

Sref2

1L

δ x−xs

L [kg.m-2.s-2]

whereρs : air density directly opposite the singularity [kg.m-3]ξs : head loss coefficient of the singularity [-]Qvs : flow rate directly opposite the singularity [m3.s-1]Sref : reference surface area linked with the singularity [m2]L : length of the tunnel section or ramp [m]δ : Dirac’s function

76

xs : abscissa of the singularity [m]

3.3 Conservation of enthalpyCAMATT solves the equation expressing the conservation of enthalpy as follows:

∂ρh∂ t

∂ρuh∂x

=Senth

whereρ : air density [kg.m-3]h : specific enthalpy of air [J.kg-1]u : air velocity [m.s-1]S enth : enthalpy volume source [W.m-3]t : time [s]x : curvilinear abscissa along the length of the tunnel [m]

The enthalpy source term Senth represents the variation over time of the enthalpy of air per unit of volume due to the:

amount of heat emitted by the seat of the fire

convective heat transfers between air and walls

radiant heat transfers between smoke and walls

transfers of heat during the blowing or extraction of air

The enthalpy source term Senth can therefore be described as:

S enth=∆ Hinc∆ Hcon∆Hray∆ Hins∆ Hext

where∆Hinc : amount of heat emitted by the seat of the fire per unit of volume [W.m-3 ]∆Hcon : variation of enthalpy over time per unit of volume due to convective transfers between air and walls [W.m-3 ]∆Hray : variation of enthalpy over time per unit of volume due to radiant transfers between smoke and walls [W.m-3 ]∆Hins : variation of enthalpy over time per unit of volume due to air blowing [W.m-3 ]∆Hext : variation of enthalpy over time per unit of volume due to air extraction [W.m-3 ]

3.3.1 Amount of heat emitted by the seat of the fire

The amount of heat emitted by the seat of the fire corresponds to a local rather than a linear enthalpy source term. However, as described for the momentum source terms (or sinks) (see section 3.2), a local source term can be equated to a linear source term using Dirac’s function. Therefore, the amount of heat emitted by the seat of a fire per unit of volume can be written as:

∆ Hinc=23

Q̇ t

SLδ

x−x j

L [W.m-3]

whereQ̇t : total amount of heat emitted by the seat of the fire [W]S : tunnel section or ramp [m2]L : length of the tunnel section or ramp [m]δ : Dirac’s functionxj : abscissa of the fire [m]

CAMATT assumes that only two thirds of the total amount of heat emitted by a fire is transferred to the air via convection, the other third being dissipated via direction radiation to the tunnel walls directly opposite the fire.

77

3.3.2 Convective heat transfers with walls

In the presence of a fire, convective transfers between air and walls induce a variation in enthalpy over time per unit of volume that can be expressed as:

∆ Hcon=−ΠS

hcT−Tp [W.m-3]

where

hc=

λ8

Cp ρ u

1,0712,7Pr23−1λ

8

7

whereΠ : perimeter of the tunnel section or ramp [m]S : tunnel section or ramp [m2]hc : convective transfer coefficient [W.m-2.K-1]T : air temperature [K]Tp : wall temperature [K]λ : Moody friction coefficient [-]Cp : specific heat of air at constant pressure (=1000) [J.kg-1.K-1]ρ : air density [kg.m-3]u : air velocity [m.s-1]Pr : Prandtl number for air set at 0.7 [-]

3.3.3 Radiant heat transfers with walls

In the presence of a fire, radiant transfers between smoke, equated with a black body, and walls 8, equated with a grey body with constant emissivity, induce a variation of enthalpy over time per unit of volume that can be expressed as:

∆ Hray=−ΠS

hr T−Tp avec hr=εo FTTpT2Tp

2 [W.m-3]

whereΠ : perimeter of the tunnel section or ramp [m]S : tunnel section or ramp [m2]hr : radiant heat transfer coefficient [W.m-2.K-1]T : air temperature [K]Tp : wall temperature [K]ε : wall emissivity [-]σo : Stefan-Boltzmann constant set at 5.68.10-8 [W.m-2.K-4]F : shape factor [-]

3.3.4 Transfers of heat during air blowing

Air can be blown into a tunnel or ramp by:

distributed blowing vents

local blowing vents

injectors

aeraulic transparencies when the difference between the pressure imposed outside and that in the tunnel is positive

Air can also enter the tunnel or ramp via one of its portals.

The variation of enthalpy over time per unit of volume induced by blown air ∆Hins can therefore be described as:

7 Formula de Petukhov8 in a single-dimension, smoke is assumed to fill the whole tunnel section and any related ramps

78

∆ H ins=∆ H bsr∆ Hbsp∆ Hinj∆ H str∆ H st

where∆Hbsr : variation of enthalpy over time per unit of volume

due to air blown by distributed blowing vents [W.m-3]∆Hbsp : variation of enthalpy over time per unit of volume due to air blown by local blowing vents [W.m-3]∆Hinj : variation of enthalpy over time per unit of volume due to air blown by injectors [W.m-3]∆Hstr : variation of enthalpy over time per unit of volume due to air blown by aeraulic transparencies [W.m-3]∆Hst : variation of enthalpy over time per unit of volume due to air blown by portals [W.m-3]

Distributed blowing vents

Air blown by distributed blowing vents in a tunnel section or ramp induces a variation of enthalpy over time per unit of volume (∆Hbsr) that can be expressed as:

∆ Hbsr=ρo

SQv bsr hbsr [W.m-3]

whereρo : ambient air density [kg.m-3]S : tunnel section or ramp [m2]Qv bsr : blowing vent flow rate per unit of length [m3.s-1.m-1]hbsr : specific enthalpy in the air blown by the distributed blowing vents [J.kg1]

Local blowing vents

As described above (see section 3.2), a local source term can be equated to a linear source term using Dirac’s function. Air blown by local blowing vents induces a variation of enthalpy over time per unit of volume (∆hbs) which can therefore be expressed as:

∆ Hbsp=ρo

SQv bsp

hbsp

Lδ

x−xbsp

L [W.m-3]

whereρo : ambient air density [kg.m-3]S : tunnel section or ramp [m2]Qv bsp : blowing vent flow rate [m3.s-1]hbsp : specific enthalpy in the air blown by the blowing vent [J.kg1]L : length of the tunnel section or ramp [m]δ : Dirac’s functionxbsp : abscissa of the blowing vent [m]

Injectors

As with a local blowing vent, air blown by an injector induces a variation of enthalpy over time per unit of volume (∆Hi) that can be expressed as:

∆ Hinj=ρo

SQv inj

h inj

Lδ

x−xinj

L [W.m-3]

whereρo : ambient air density [kg.m-3]S : tunnel section or ramp [m2]Qv inj : blowing injector flow rate [m3.s-1]hinj : specific enthalpy of injector blown air [J.kg1]L : length of the tunnel section or ramp [m]δ : Dirac’s functionxinj : abscissa of the injector [m]

Aeraulic transparencies

In contrast to local or distributed blowing vents and injectors, an aeraulic transparency only blows air into a tunnel section or ramp if the difference between the pressure imposed outside and that in the tunnel is

79

positive. In this case, air blown by an aeraulic transparency induces a variation of enthalpy over time per unit of volume (Hstr) that can be expressed as:

∆ Hstr=ρo

S 2∣Pt−Pe∣ξtrρo

Str

hstr

Lδ

x−x tr

L [W.m-3]

whereρo : ambient air density [kg.m-3]S : tunnel section or ramp [m2]Pt : tunnel air pressure directly opposite aeraulic transparency [Pa]Pe : imposed air pressure outside the aeraulic transparency [Pa]ξtr : head loss coefficient of the aeraulic transparency set at 1.5 [-]Str : cross-section of the aeraulic transparency [m2]hstr : specific enthalpy of air blown by the aeraulic transparency [J.kg1]L : length of the tunnel section or ramp [m]δ : Dirac’s functionxtr : abscissa of the aeraulic transparency [m]

Air entering via the portals

Air entering a tunnel section or ramp via the portals induces a variation of enthalpy over time per unit of volume (∆Hst) that can be expressed as:

∆ Hst=ρo

SQv st

hst

Lδ

x−xst

L [W.m-3]

whereρo : ambient air density [kg.m-3]S : tunnel section or ramp [m2]Qv st : flow rate entering via a portal [m3.s-1]hst : specific enthalpy of air entering via a portal [J.kg1]L : length of the tunnel section or ramp [m]δ : Dirac’s functionxst : abscissa of the portal [m]

3.3.5 Transfers of heat during air extraction

Air can be extracted from a tunnel or ramp by:

distributed extraction dampers

local extraction dampers

massive extraction

aeraulic transparency, when the difference between the pressure imposed outside and that in the tunnel is negative

Air can also escape from a tunnel or ramp via one of its portals.

The variation of enthalpy over time per unit of volume induced by air extraction ∆hext can therefore be described as:

∆ H ext=∆ H ter∆ H tep∆ Hem∆ Hetr∆ Het

where∆Hter : variation of enthalpy over time per unit of volume

due to air extracted by distributed extraction dampers [W.m-3]∆Htep : variation of enthalpy over time per unit of volume due to air extracted by local extraction dampers [W.m-3]∆Hem : variation of enthalpy over time per unit of volume due to air extracted by massive extractions [W.m-3]∆Hetr : variation of enthalpy over time per unit of volume due to air extracted by aeraulic transparencies [W.m-3]∆Het : variation of enthalpy over time per unit of volume due to air extracted via portals [W.m-3]

80

Distributed extraction dampers

Air extracted by distributed extraction dampers in a tunnel section or ramp induces a variation of enthalpy over time per unit of volume (∆Hter) that can be expressed as:

∆ Hter=−ρo

SQv etr hter [W.m-3]

whereρo : ambient air density [kg.m-3]S : tunnel section or ramp [m2]Qv ter : extraction damper flow rate per unit of length [m3.s-1.m-1]hter : specific enthalpy of air extracted by distributed extraction dampers [J.kg1]

Local extraction dampers

As described above (see section 3.2), a local sink can be equated to a linear sink using Dirac’s function. Air extracted by a local extraction damper induces a variation of enthalpy over time per unit of volume (∆hes) which can be expressed as:

∆ Htep=−ρo

SQv tep

htep

Lδ

x−xtep

L [W.m-3]

whereρo : ambient air density [kg.m-3]S : tunnel section or ramp [m2]Qv tep : extraction damper flow rate [m3.s-1]htep : specific enthalpy of air extracted by an extraction damper [J.kg1]L : length of the tunnel section or ramp [m]δ : Dirac’s functionxtep : abscissa of the extraction damper [m]

Massive extractions

As with an extraction damper, air extracted by massive extraction induces a variation of enthalpy over time per unit of volume (Hem) that can be expressed as:

∆ Hem=−ρem

SQv em

hem

Lδ

x−xem

L [W.m-3]

whereρem : air density directly opposite the massive extraction [kg.m-3]S : tunnel section or ramp [m2]Qv em : massive extraction flow rate [m3.s-1]hem : specific enthalpy of air extracted by massive extraction [J.kg1]L : length of the tunnel section or ramp [m]δ : Dirac’s functionxem : abscissa of massive extraction [m]


In contrast to local or distributed extraction dampers and injectors, an aeraulic transparency only blows air into a tunnel section or ramp if the difference between the pressure imposed outside and that in the tunnel is negative. In this case, air extracted by an aeraulic transparency induces a variation of enthalpy over time per unit of volume (∆Hetr) that can be expressed as:

∆ Hstr=−ρ tr

S 2∣Pt−Pe∣ξtrρ tr

Str

hetr

Lδ

x−x tr

L [W.m-3]

whereρtr : Air density opposite the aeraulic transparency [kg.m-3]S : tunnel section or ramp [m2]Pt : tunnel air pressure directly opposite aeraulic transparency [Pa]Pe : imposed air pressure outside the aeraulic transparency [Pa]ξtr : head loss coefficient of the aeraulic transparency set at 1,5 [-]Str : section of the aeraulic transparency [m2]hetr : specific enthalpy of air extracted by aeraulic transparency [J.kg1]

81

L : length of the tunnel section or ramp [m]δ : Dirac’s functionxtr : abscissa of the aeraulic transparency [m]

Air exiting via the portals

Air exiting from a tunnel section or ramp via a portal induces a variation of enthalpy over time per unit of volume (∆Het) that can be expressed as:

∆ Het=−ρet

SQv et

het

Lδ

x−xet

L [W.m-3]

whereρet : air density at the portal [kg.m-3]S : tunnel section or ramp [m2]Qv et : portal exit flow rate [m3.s-1]het : specific enthalpy of air exiting via the portal [J.kg1]L : length of the tunnel section or ramp [m]δ : Dirac’s functionxet : abscissa of the portal [m]

3.4 Heating of wallsThe heat flows transferred with tunnel walls via convection and radiation (∆Hcon and ∆Hray) factor in the heating of walls due to conductive heat transfers within the structure and their impact on airflow in the tunnel.

This heating of walls is factored in using Fourier’s equation which is also solved by CAMATT:

ρs Cps

∂Ts∂ t

λs

∂2Ts∂ z2

=0

whereρs : density of wall materials [kg.m-3 ]Cps : specific heat of wall materials [J.kg-1.K-1 ]Ts : temperature of the structure at depth z [K]λs : thermal conductivity of wall materials [W.m-1.K-1 ]t : time [s]z : depth [m]

CAMATT is used to factor in walls made of two different materials at the most. It therefore solves Fourier’s equation using equivalent thermo-physical properties that are calculated as follows:

ρs=pmat 1 ρs11−pmat 1ρs2

Cps=pmat 1Cps11−pmat 1Cps2

λs=pmat 1 λs11−pmat 1λs2

wherepmat 1 : proportion of material 1 to material 2 [-]ρs1 : density of wall material 1 [kg.m-3 ]ρs2 : density of wall material 2 [kg.m-3 ]Cps1 : specific heat of wall material 1 [J.kg-1.K-1 ]Cps2 : specific heat of wall material 2 [J.kg-1.K-1 ]λs1 : thermal conductivity of wall material 1 [W.m-1.K-1 ]λs2 : thermal conductivity of wall material 2 [W.m-1.K-1 ]

To solve Fourier’s equation, CAMATT considers that the tunnel section or ramp is an annular section with thickness16 cm comprising 8 concentric rings:

82

Ring thickness

1 07 mm

2 10 mm

3 12 mm

4 15 mm

5 20 mm

6 25 mm

At each ring i, CAMATT links a mean temperature for the structure Tsai calculated using Fourier’s equation.

The limit conditions factored in by CAMATT are given below:

no conductive heat transfer beyond a depth of 16 cm

conservation of heat flows at the interface between the air and the tunnel wall that can be expressed as:

hchrT−Tp=2λs

Tp−Tsa1

ea1

wherehc : convective transfer coefficient [W.m-2.K-1]hr : radiant heat transfer coefficient [W.m-2.K-1]T : air temperature [K]Tp : wall temperature [K]λs : thermal conductivity of the material making up the structure [W.m-1.K-1]Tsa1 : mean temperature of the wall’s first ring [K]ea1 : thickness of the first ring set at 7.10-3 [m]

3.5 Thermodynamic equationsCAMATT solves the following thermodynamic equations:

3.5.1 Equation of state

The air in the tunnel is equated to a perfect incompressible gas. Its density is therefore assumed to depend solely on variations in temperature, and not on variations in pressure, which are deemed too small with respect to atmospheric pressure.

CAMATT therefore solves the perfect gas equation as follows:

ρ T=MPo

R

whereρ : air density [kg.m-3]T : air temperature [K]M : molar mass of air [kg.mol-1]Po : atmospheric pressure set at 101 325 [Pa]R : perfect gas constant set at 8.315 [J.mol-1.K-1]

CAMATT only uses this equation to calculate air density ρ and its temperature T.

3.5.2 Specific enthalpy

The air in the tunnel is equated to a perfect gas. Its specific enthalpy therefore depends solely on its temperature, and not on variations in pressure, which are deemed too small with respect to atmospheric pressure.

In addition, the specific heat of air at constant pressure varies very little with respect to the temperatures that may be encountered in a tunnel following a fire.

83

CAMATT therefore solves the equation linking specific enthalpy to air temperature as follows:

h=Cp T

whereh : specific enthalpy of air [J.kg-1]Cp : specific heat of air at constant pressure set at 1 000 [J.kg-1.K-1]T : air temperature [K]

This equation is used to solve the conservation of enthalpy equation.

3.6 Transport of a passive scalar A passive scalar is a physical quantity that is simply subject to transport phenomena, without effecting flow behaviour. CAMATT is used to factor in two types of passive scalar: gaseous pollutant concentrations and air opacity.

3.6.1 Gaseous pollutants

In “Fire mode", CAMATT solves the equation expressing in-flow gaseous pollutant transport as follows:

∂ cp∂ t

∂ucp ∂x

=S p

wherecp : concentration of gaseous pollutant in air [kg.m-3]u : air velocity [m.s-1]S p : mass source (or sink) of the gaseous pollutant [kg.m-3.s-1]t : time [s]x : curvilinear abscissa along the length of the tunnel [m]

In “Pollution mode", this equation is solved in steady state regime, and therefore becomes:

∂ uc p∂x

=S p

The mass source term (or sink) for a gaseous pollutant S pol represents the variation over time of the mass of the gaseous pollutant per unit of volume that takes account of:

gaseous pollutants emitted by the seat of a fire in “Fire mode"

gaseous pollutants emitted by road traffic in “Pollution mode"

gaseous pollutants blown into a tunnel or ramp by:▪ distributed blowing vents▪ local blowing vents▪ injectors▪ aeraulic transparencies when the difference between the pressure imposed outside and that in the

tunnel is positive

gaseous pollutants extracted from a tunnel or ramp by:▪ distributed extraction dampers▪ local extraction dampers▪ massive extractions▪ aeraulic transparencies when the difference between the pressure imposed outside and that in the

tunnel is negative

gaseous pollutants entering the tunnel or ramp via a portal

gaseous pollutants exiting the tunnel or ramp via a portal

The variation over time of the mass of a gaseous pollutant per unit of volume can therefore be written as:

S p=S p eS p bsrS p terS p bspSp tepSp injSp emSp strS p etrSp stS p et

whereSp e : variation over time of the mass of the pollutant per unit of volume due to emissions in the tunnel [kg.m-3.s-1]Sp bsr : variation over time of the mass of the pollutant per unit of volume

due to air blown by distributed blowing vents [kg.m-3.s-1]

84

Sp ter : variation over time of the mass of the pollutant per unit of volume due to air extracted by distributed extraction dampers [kg.m-3.s-1]Sp bsp : variation over time of the mass of the pollutant per unit of volume

due to air blown by local blowing vents [kg.m-3.s-1]Sp tep : variation over time of the mass of the pollutant per unit of volume due to air extracted by local extraction dampers [kg.m-3.s-1]Sp inj : variation over time of the mass of the pollutant per unit of volume due to air blown by injectors [kg.m-3.s-1]Sp em : variation over time of the mass of the pollutant per unit of volume due to air extracted by massive extraction [kg.m-3.s-1]Sp str : variation over time of the mass of the pollutant per unit of volume due to air blown by aeraulic transparencies [kg.m-3.s-1]Sp etr : variation over time of the mass of the pollutant per unit of volume due to air extracted by aeraulic transparencies [kg.m-3.s-1]Sp st : variation over time of the mass of the pollutant per unit of volume due to air entering via the portals [kg.m-3.s-1]Sp et : variation over time of the mass of the pollutant per unit of volume due to air exiting via the portals [kg.m-3.s-1]

For calculations in “Fire mode", the gaseous pollutant factored in for fires is carbon monoxide (CO); however, it is possible to factor in another pollutant by changing the pollutant emission flow rate value.

Emissions of gaseous pollutants from the seat of a fire

Emissions of CO from the seat of a fire correspond to a local rather than a linear mass source term. However, as specified for the momentum source terms (or sinks) (see section 3.2), a local source term can be equated to a linear source term using Dirac’s function. The CO mass source term for the seat of a fire per unit of volume (Sp e) can therefore be written as:

Sp e=Qm CO

SLδ

x−xj

L [kg.m-3.s-1]

whereQm CO : mass flow of CO emitted by the seat of the fire [kg.s-1]S : tunnel section or ramp [m2]L : length of the tunnel [m]δ : Dirac’s functionxj : abscissa of the fire [m]

Emissions of gaseous pollutants by road traffic

Emissions of gaseous pollutants by road traffic are only factored in for calculations in “Pollution mode” as they are negligible with respect to emissions from the seat of a fire.

The road traffic found in a tunnel section or ramp induces for each gaseous pollutant a variation over time of its mass per unit of volume (Sp e) that can be expressed as:

Sp e=ep

S[kg.m-3.s-1]

whereep : mass flow of the gaseous pollutant per unit of length emitted by road traffic [kg.s-1.m-1]S : tunnel section or ramp [m2]


Air blown by distributed blowing vents in a tunnel section or ramp induces for each gaseous pollutant a variation over time of its mass per unit of volume (Sp bsr) that can be expressed as:

Sp bsr=cop bsr

SQv bsr [kg.m-3.s-1]

wherecop bsr : concentration of the gaseous pollutant in air blown by distributed blowing vents [kg.m-3]S : tunnel section or ramp [m2]Qv bsr : blowing vent flow rate per unit of length [m3.s-1.m-1]

85


Air extracted by distributed extraction dampers in a tunnel section or ramp induces for each gaseous pollutant a variation over time of its mass per unit of volume (Sp ter) that can be expressed as:

Sp ter=−cp

SQv ter [kg.m-3.s-1]

wherecp : concentration of the gaseous pollutant in air extracted by distributed extraction dampers [kg.m-3]S : tunnel section or ramp [m2]Qv ter : extraction damper flow rate per unit of length [m3.s-1.m-1]

Local blowing vents

As described above (see section 3.2), a local source term can be equated to a linear source term using Dirac’s function. Air blown by a local blowing vent induces for each gaseous pollutant a variation over time of its mass per unit of volume (Sp bsp) that can be expressed as:

Sp bsp=cop bsp

SQv bsp

1L

δ x−xbsp

L [kg.m-3.s-1]

wherecop bsp : concentration of the gaseous pollutant in air blown by a blowing vent [kg.m-3]S : tunnel section or ramp [m2]Qv bsp : blowing vent flow rate [m3.s-1]δ : Dirac’s functionxbsp : abscissa of the blowing vent [m]


As described above (see section 3.2), a local sink can be equated to a linear sink using Dirac’s function. Air extracted by an extraction damper induces for each gaseous pollutant a variation over time of its mass per unit of volume (Sp tep) that can be expressed as:

Sp tep=−cp

SQv tep

1L

δ x−x tep

L [kg.m-3.s-1]

wherecp : concentration of the gaseous pollutant in air extracted by extraction damper [kg.m-3]S : tunnel section or ramp [m2]Qv tep : extraction damper flow rate [m3.s-1]δ : Dirac’s functionxtep : abscissa of the extraction damper [m]

Injectors

As with a local blowing vent, air blown by an injector induces for each gaseous pollutant a variation over time of its mass per unit of volume (Sp inj) that can be expressed as:

Sp inj=cop inj

SQv inj

1L

δ x−x inj

L [kg.m-3.s-1]

wherecop inj : concentration of the gaseous pollutant in air blown by the injector [kg.m-3]S : tunnel section or ramp [m2]Qv inj : injector flow rate [m3.s-1]δ : Dirac’s functionxinj : abscissa of the injector [m]

Massive extractions

As with a local extraction damper, air extracted by a massive extraction induces for each gaseous pollutant a variation over time of its mass per unit of volume (Sp em) that can be expressed as:

86

Sp em=−cp

SQv em

1L

δ x−x em

L [kg.m-3.s-1]

wherecp : concentration of the gaseous pollutant in air extracted by massive extraction [kg.m-3]S : tunnel section or ramp [m2]Qv em : massive extraction flow rate [m3.s-1]δ : Dirac’s functionxem : abscissa of the massive extraction [m]


An aeraulic transparency only blows air into a tunnel section or ramp if the difference between the pressure imposed outside and that in the tunnel is positive.

In this case, air blown by the aeraulic transparency induces for each gaseous pollutant a variation over time of its mass per unit of volume (Sp str) that can be expressed as:

Sp str=cop tr

S 2∣Pt−Pe∣ξtr ρo

Str1L

δ x−x tr

L [kg.m-3.s-1]

wherecop tr : concentration of the gaseous pollutant in air blown by the aeraulic transparency [kg.m-3]S : tunnel section or ramp [m2]Pt : tunnel air pressure opposite the aeraulic transparency [Pa]Pe : imposed air pressure outside the aeraulic transparency [Pa]ξtr : head loss coefficient of the aeraulic transparency set at 1.5 [-]L : length of the tunnel section or ramp [m]δ : Dirac’s functionxtr : abscissa of the aeraulic transparency [m]

In other cases, air extracted by the aeraulic transparency induces for each gaseous pollutant a variation over time of its mass per unit of volume (Sp etr) that can be expressed as:

Sp str=−cp

S 2∣Pt−Pe∣ξtr ρ tr

Str1L

δ x−xtr

L [kg.m-3.s-1]

wherecp : concentration of the gaseous pollutant in air extracted by an aeraulic transparency [kg.m-3]


Air entering a tunnel section or ramp via a portal induces for each gaseous pollutant a variation over time of its mass per unit of volume (Sp st) that can be expressed as:

Sp st=cop st

SQv st

1L

δ x−x st

L [kg.m-3.s-1]

wherecop st : concentration of the pollutant in air entering via a portal [kg.m-3]S : tunnel section or ramp [m2]Qv st : flow rate entering via a portal [m3.s-1]L : length of the tunnel section or ramp [m]δ : Dirac’s functionxst : abscissa of the portal [m]


Air exiting from a tunnel section or ramp via a portal induces for each gaseous pollutant a variation over time of its mass per unit of volume (Sp and) that can be expressed as:

Sp et=−cp

SQv et

1L

δ x−xet

L [kg.m-3.s-1]

avec

wherecp : concentration of the gaseous pollutant in air exiting via a portal [kg.m-3]

87

S : tunnel section or ramp [m2]Qv et : flow rate exiting via a portal [m3.s-1]L : length of the tunnel section or ramp [m]δ : Dirac’s functionxet : abscissa of the portal [m]

3.6.2 Air opacity

For soot and particulate matter, the passive scalar selected in CAMATT is air opacity quantified through the extinction coefficient9 that represents the relative loss in luminous flux per unit of length.

In “Fire mode”, CAMATT solves the equation expressing the transport of opacity in the flow as follows:

∂ k ∂ t

∂uk ∂x

=S k

wherek : extinction coefficient for air [m-1]u : air velocity [m.s-1]S p : opacity source (or sink) [m-1.s-1]t : time [s]x : curvilinear abscissa along the length of the tunnel [m]

In “Pollution mode", this equation is solved in steady state regime and therefore becomes:

∂ uk ∂x

=Sk

The opacity source term (or sink) S k represents the variation over time of opacity that factors in:

soot emitted by the seat of a fire in “Fire mode"

particulates emitted by road traffic in “Pollution mode"

particulates blown into the tunnel or ramp by:▪ distributed blowing vents▪ local blowing vents▪ injectors▪ aeraulic transparencies when the difference between the pressure imposed outside and that in the

tunnel is positive

particulates extracted from the tunnel or ramp by:▪ distributed extraction dampers▪ local extraction dampers▪ massive extractions▪ aeraulic transparencies when the difference between the pressure imposed outside and that in the

tunnel is negative

particulates entering the tunnel or ramp via a portal

particulates exiting the tunnel or ramp via a portal

The variation over time of opacity can therefore be written as:

S k=S k eS k bsrS k terSk bspS k tepS k injSk emS k strSk etrS k stS k st

whereSk e : variation over time of opacity due to emissions in the tunnel [m-1.s-1]Sk bsr : variation over time of opacity due to air blown by distributed blowing vents [m-1.s-1]Sk ter : variation over time of opacity due to air extracted by distributed extraction dampers [m-1.s-1]Sk bsp : variation over time of opacity due to air blown by local blowing vents [m-1.s-1]Sk tep : variation over time of opacity due to air extracted by local extraction dampers [m-1.s-1]

9 Also referred to as the optical absoption coefficient

88

Sk inj : variation over time of opacity due to air blown by injectors [m-1.s-1]Sk em : variation over time of opacity due to air extracted by massive extractions [m-1.s-1]Sk str : variation over time of opacity due to air blown by aeraulic transparencies [m-1.s-1]Sk etr : variation over time of opacity due to air extracted by aeraulic transparencies [m-1.s-1]Sk st : variation over time of opacity due to air entering via the portals [m-1.s-1]Sk and : variation over time of opacity due to air exiting via the portals [m-1.s-1]

Emissions of soot from the seat of a fire

Emissions of soot from the seat of a fire correspond to a local rather than a linear mass source term. However, as specified for the momentum source terms (or sinks) (see section 3.2), a local source term can be equated to a linear source term using Dirac’s function. The opacity source term for the seat of a fire (Sk e) can therefore be written as:

Sk e=Φk

SLδ

x−xj

L [m-1.s-1]

whereΦk : opacity flux emitted by the seat of the fire [m3.s-1.m-1 ]S : tunnel section or ramp [m2]L : length of the tunnel [m]δ : Dirac’s functionxj : abscissa of the fire [m]

Emissions of particulates from road traffic

Emissions of particulates from road traffic are only factored in for calculations in “Normal extraction mode” as they are negligible with respect to emissions of soot from the seat of a fire.

The road traffic found in a tunnel section or ramp induces a variation over time of opacity (S k e) that can be expressed as:

Sk e=αek

S[m-1.s-1]

whereα : unit conversion factor [m-1.kg-1.m3]ek : mass flow in particulates per unit of length of road traffic [kg.s-1.m-1]S : tunnel section or ramp [m2]


Air blown by distributed blowing vents in a tunnel section or ramp induces a variation over time of opacity (Sk bsr) that can be expressed as:

Sk bsr=ko bsr

SQv bsr [m-1.s-1]

whereko bsr : extinction coefficient for air blown by distributed blowing vents [m-1]S : tunnel section or ramp [m2]Qv bsr : blowing vent flow rate per unit of length [m3.s-1.m-1]


Air extracted by distributed extraction dampers in a tunnel section or ramp induces a variation over time of opacity (Sk ter) that can be expressed as:

Sk ter=−kS

Qv ter [m-1.s-1]

89

wherek : extinction coefficient of air [m-1]S : tunnel section or ramp [m2]Qv ter : extraction damper flow rate per unit of length [m3.s-1.m-1]

Local blowing vents

As described above (see section 3.2), a local source term can be equated to a linear source term using Dirac’s function. Air blown by a local blowing vent induces a variation over time of opacity (Sk bsp) that can be expressed as:

Sk bsp=ko bsp

SQv bsp

1L

δx−xbsp

L [m-1.s-1]

whereko bsp : extinction coefficient for air blown by a blowing vent [m-1]S : tunnel section or ramp [m2]Qv bsp : blowing vent flow rate [m3.s-1]δ : Dirac’s functionxbsp : abscissa of the blowing vent [m]


As described above (see section 3.2), a local sink can be equated to a linear sink using Dirac’s function. Air extracted by an extraction damper induces a variation over time of opacity (Sk tep) that can be expressed as:

Sk tep=−kS

Qv tep1L

δ x−x tep

L [m-1.s-1]

wherek : extinction coefficient of air [m-1]S : tunnel section or ramp [m2]Qv tep : extraction damper flow rate [m3.s-1]δ : Dirac’s functionxtep : abscissa of the extraction damper [m]

Injectors

As with a local blowing vent, air blown by an injector induces a variation over time of opacity (S k inj) that can be expressed as:

Sk inj=ko inj

SQv inj

1L

δ x−xinj

L [m-1.s-1]

whereko inj : extinction coefficient in injector blown air [m-1]S : tunnel section or ramp [m2]Qv inj : injector flow rate [m3.s-1]δ : Dirac’s functionxinj : abscissa of the injector [m]

Massive extractions

As with local extraction dampers, air extracted via massive extraction induces a variation over time of opacity (Sk em) that can be expressed as:

Sk em=− kS

Qv em1L

δ x−xem

L [m-1.s-1]

wherek : extinction coefficient of air [m-1]S : tunnel section or ramp [m2]Qv em : massive extraction flow rate [m3.s-1]δ : Dirac’s functionxem : abscissa of the massive extraction [m]

90


An aeraulic transparency only blows air into a tunnel section or ramp if the difference between the pressure imposed outside and that in the tunnel is positive.

In this case, air blown by the aeraulic transparency induces a variation over time of opacity (S k str) that can be expressed as:

Sk str=ko tr

S 2∣Pt−Pe∣ξtr ρo

Str1L

δx−xtr

L [m-1.s-1]

whereko tr : extinction coefficient in the aeraulic transparency blown air [m-1]S : tunnel section or ramp [m2]Pt : tunnel air pressure directly opposite an aeraulic transparency [Pa]Pe : imposed air pressure outside an aeraulic transparency [Pa]ξtr : head loss coefficient of the aeraulic transparency set at 1.5 [-]L : length of the tunnel section or ramp [m]δ : Dirac’s functionxtr : abscissa of the aeraulic transparency [m]

In other cases, air extracted via aeraulic transparency induces a variation over time of opacity (Sp etr) that can be expressed as:

Sk str=− kS 2∣Pt−Pe∣

ξtrρ tr

Str1L

δ x−xtr

L [m-1.s-1]

wherek : extinction coefficient of air [m-1]


Air entering a tunnel section or ramp via a portal induces a variation over time of opacity (Sk st) that can be expressed as:

Sk st=ko st

SQv st

1L

δ x−x st

L [m-1.s-1]

whereko tr : extinction coefficient of air entering via a portal [m-1]S : tunnel section or ramp [m2]Qv st : flow rate entering via a portal [m3.s-1]L : length of the tunnel section or ramp [m]δ : Dirac’s functionxst : abscissa of the portal [m]


Air exiting from a tunnel section or ramp via a portal induces a variation over time of opacity (S k and) that can be expressed as:

Sk et=− kS

Qv et1L

δ x−xet

L [m-1.s-1]

wherek : extinction coefficient of air [m-1]S : tunnel section or ramp [m2]Qv et : flow rate exiting via a portal [m3.s-1]L : length of the tunnel section or ramp [m]δ : Dirac’s functionxet : abscissa of the portal [m]

91

92

93

CONTRIBUTORSFrédéric VINCENT, Xavier PONTICQ, Antoine MOS and Jean-François BURKHART participated in the drafting of this document.

www.cetu.developpement-durable.gouv.fr

Tunnels Study Centre

25, avenue François Mitterrand

Case n°1

69674 BRON - FRANCE

Tél. 33 (0)4 72 14 34 00

Fax. 33 (0)4 72 14 34 30

[email protected]

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