Professorial Lecture Feb 2009 Final Version Notes2 Lecture...Overview of CFD Introduction CFD &...

2/18/2009

1

ADVANCES IN THE DEVELOPMENT ADVANCES IN THE DEVELOPMENT OF INDIGENOUS COMPUTATIONAL OF INDIGENOUS COMPUTATIONAL

FLUID DYNAMICS (CFD) SOFTWARE FLUID DYNAMICS (CFD) SOFTWARE IN MALAYSIAIN MALAYSIA

Mohd Zamri Y soffMohd Zamri YusoffCentre for Advanced Computational Engineering

College of EngineeringUniversiti Tenaga Nasional

UNITEN Generates Professionals

Contents

CFD & Fluid Governing Equations

Introduction

Improved Numerical Formulations

VRSIM CFD Software

FLOWSIM CFD Software

High Speed Transient Flows

Two Phase Condensing Flows

Conclusions


2/18/2009

2

Contents


IntroductionIntroduction


VRSIM CFD Software




Conclusions


IntroductionConcept of Simulation of Reality

Real World Phenomena

PREDICTION OF REAL WORD

PHENOMENA

Fundamental Laws of Nature EmpiricalPhenomena

Further Simplifications Direct Numerical Solution

with Computer

Mathematical Models

Empirical Models

of Nature + Assumptions

Empirical Observation


Analytical Solutions Numerical

Solutions

with Computer

2/18/2009

3

Introduction

Real World Phenomena

All the mathematical sciences are founded on relations between

physical laws and laws of numbers, so that the aim of exact science is to Phenomenareduce the problems of nature to the

determination of quantities by operations with numbers

James Clerk Maxwell (1856)


IntroductionFluid Flow Simulations

Fluid Flow Phenomena

PREDICTION OF FLUID

FLOW PHENOMENA

Conservation Laws of Nature EmpiricalPhenomena

Further Simplifications Direct Numerical Solution

with Computer

Navier-Stokes Equation

Turbulence & Other Models

of Nature+ Assumptions

Empirical Observation


Analytical Solutions CFD

Solutions

with Computer

2/18/2009

4

What is CFD ?Formal Definition : CFD is the Analysis of Systems Involving

Fluid Flow, Heat Transfer and Associated Phenomena Such as Chemical Reactions By Means of Computer-Based Simulation

(Verstegg & Malalasekera, 1995)( gg , )

Layman Definition : It is the attempt to predict, quantitatively if possible, what will happen if, for example:• a kettle is placed on the hot-plate of an electric cooker;• a wind-turbine is placed on a hill-top; • an ignited explosive forces a bullet from a gun;• a swimmer dives into water; or


• a parachutist falls gradually to the ground(Brian Spalding, 2007 on his 80th Birthday Lecture)

Why Use CFD ?

Analysis and Design : Simulation-based design instead of experiment-based

Substantial reduction of lead times and cost of new designAbility to do ‘What-If’ scenario analysis

Ability to study systems where controlled experiments are difficult or impossible to perform

Full scale system e.g ship hull, aircrafty g p ,Ability to study system under hazardous conditionsVery large system e.g weather prediction

Knowledge and exploration of flow physics


2/18/2009

5

CFD Analysis Process

Geometry MESH Par Track

AnimationsCBA

Fluid Props

Model/App

Bound Cond

PRE-Processor SOLVER

Finite Diff

Finite Vol

Finite Elem

POST-Processor

Contours

Line Plot

Vel Vectors


Where is CFD Used ?

AerospaceAppliancesAutomotiveBiomedicalChemicalProcessingHydraulicsM iMarineOil & GasPower GenerationSports


2/18/2009

6

Where is CFD Used ?

AerospaceAppliancesAutomotiveBiomedicalChemicalProcessingHydraulicsM iMarineOil & GasPower GenerationSports


Commercial CFD Software

FLUENT, STARCD, CFX, FLUENT, STARCD, CFX, CFDCFD ACE FLOW3DACE FLOW3DCFDCFD--ACE, FLOW3D, ACE, FLOW3D,

PHOENICS PHOENICS , AVL, , AVL, FLOVENTFLOVENT

$$$$$$$$$$$$$$$$$$$$$$$$


2/18/2009

7

Why Indigenous CFD Software?

CFD code needs to be customized for accurate prediction of model-dependent fluid flow problem beca se of the comple it of the fl id flo sbecause of the complexity of the fluid flows

The cost of acquiring a commercial CFD software is very expensive which excludes Semi and Medium Scale Enterprises from acquiring the technology

The complexity requires user of a CFD software to have good understanding of the mathematical,have good understanding of the mathematical, physical principles of CFD and limitations of computational methods


Development of Indigenous CFD Software in UNITEN

The ultimate aim is to produce a low cost CFD software that can be used by local industry including y y gthe Semi and Medium Scale Enterprises (SME)

Two-Phase

NEWRK(2D Euler)

FLOWSIM Software

Suite

Compressible Flow2D & 3DStructured & Unstructured

VRSIMIncompressible Flow3D


FlowsVRSIM

Software3DStructured Cartesian

Improved Numerical Schemes

Transient High Speed Flow

2/18/2009

8

Contents

Overview of CFD

Introduction



VRSIM CFD Software




Conclusions


CFD & Fluid Governing EquationsSome Quotes From the Holy Qur’an : -

"It is He who gives life and death, and when He ordains a thing, He says only 'Be' and it is"

(Al-Mukmin:68)

"He gave everything its form, then gave it guidance" (Taha:50) … His creation obeys His rules, or "laws of nature", which enables them to fit into the order of

thi


things

“We have created all things in due measure" (Al-Qamar:49)

2/18/2009

9


“We are to admit no more causes of natural things than such as are both true and sufficient to explain

their appearances … To this purpose the philosophers say that Nature does nothing in vain,

and more is in vain when less will serve, for Nature is l d ith i li it d ff t t th f


pleased with simplicity, and affect not the pomp of superfluous causes”

Isaac Newton (Rule 1, Book II of Principia, 1687)

CFD & Fluid Governing EquationsLaw of conservation of mass

Law of conservation of x, y and z momentum ~ Newton’s 2nd Law

Law of


conservation of Energy ~ First Law of Thermodynamics

2/18/2009

10

CFD & Fluid Governing EquationsLaw of conservation of mass

Law of

( ) 0Vt

=•∇+∂∂ ρρ

conservation of x, y and z momentum ~ Newton’s 2nd Law

Law of


conservation of Energy ~ First Law of Thermodynamics

Contents


Introduction


VRSIM CFD Software

FLOWSIM CFD SoftwareFLOWSIM CFD Software



Conclusions


2/18/2009

11


CFD Software Developed in UNITENThe Aim is to Develop a Compressible 3D NavierStokes Solver for Arbitrarily Complex GeometryStokes Solver for Arbitrarily Complex Geometry Over Wide Flow Regime6 Software Modules for 2D and 3D FlowsGUI for FLOWSIM


FLOWSIM Software Modules

FLOWSIM-PRE : Geometry, Mesh Generator and Pre-Processor for SQUAD2D

FLOWSIM POST Post Processor for SQUAD2DFLOWSIM-POST : Post-Processor for SQUAD2D

FLOWSIM-SQUAD2D : Viscous 2D Navier Stokes Solver on Structured Quadrilateral Grid

FLOWSIM-TRIA2D : Viscous 2D Navier Stokes Solver on Unstructured Triangular Grid

FLOWSIM HEXA3D Visco s 3D Na ier Stokes Sol erFLOWSIM-HEXA3D : Viscous 3D Navier Stokes Solver on Unstructured Hexahedral Grid

FLOWSIM-TETRA3D : Viscous 3D Navier Stokes Solveron Unstructured Tetrahedral Grid


2/18/2009

12

FLOWSIM : Numerical Formulation

Time-Marching Method

Density Based

Fully Coupled Solver

Finite-Volume Method

Cell-Vertex Storage

2nd Order Central Spatial Discretization

4th Order Runge Kutta Temporal Discretization4th Order Runge-Kutta Temporal Discretization

Blend of 4th and 2nd Order Artificial Viscosity

Shock Capturing By Pressure Switch

Convergence Acceleration Schemes


FLOWSIM : Applications

SQUAD2D - Sajben’s Diffuser (weak shock)

Top WallTop Wall

UNITEN Generates ProfessionalsBottom WallBottom Wall

2/18/2009

13


SQUAD2D - Sajben’s Diffuser (strong shock)

Top WallTop Wall

UNITEN Generates ProfessionalsBottom WallBottom Wall


TRIA2D – Transonic Flow in RAE Airfoil

TRIA2DTRIA2D

WIND (NASA)WIND (NASA)ShockwaveShockwave


2/18/2009

14


HEXA3D – Laminar and Turbulent Flow Past a Cylinder



HEXA3D – Tubulent Flow Past a Cylinder – Hypersonic Flow and Von Karman Vortex Street Formation


Hypersonic Flow Showing Bow ShockHypersonic Flow Showing Bow Shock

High Re FlowHigh Re Flow–– Formation of Von Karman Formation of Von Karman Vortex StreetVortex Street

2/18/2009

15


HEXA3D – Transonic Flows in Blade Cascade and Nozzle



HEXA3D – DFVLR Transonic Compressor Rotor


2/18/2009

16


HEXA3D – DFVLR Transonic Compressor Rotor


FLOWSIM : ApplicationsTETRA3D – Transonic Flow Over DLRFR Aircraft


2/18/2009

17


TETRA3D – Transonic Flow Over DLRFR Aircraft

TETRA3DTETRA3D


CFD++ (CFD++ (MetacompMetacomp Technology)Technology)


TETRA3D – Supersonic Flow of F18 Aircraft

Tetrahedral MeshTetrahedral Mesh


Surface Pressure ContoursSurface Pressure Contours

2/18/2009

18

Contents


Introduction


VRSIM CFD Software


VRSIM CFD Software



Conclusions


VRSIM CFD Software

VRSIM – Virtual Room SIMulatorFull-Fledged CFD software – Geometry Creation, Mesh Generator, Pre-Processor, Solver & Post ProcessorDeveloped in Collaboration with OYL R&D CentreThe First Complete CFD Software in MalaysiaSpecifically for Indoor Air-Flow SimulationAllow Non-Expert to Use CFD for Simulating and Visualizing Thermal Properties in Enclosed RoomDesigned with Minimal User Inputs


2/18/2009

19

VRSIM : Numerical Formulation

Cartesian Hexahedral Mesh

Solve Steady Flow Incompressible Reynolds Averaged Na ier Stokes Eq ation (RANS)Navier Stokes Equation (RANS)

Segregated Solution Method (SSM)

Pressure Velocity Coupling by Semi-Implicit Pressure-Linked Equations (SIMPLE) Method

Upwind Differencing for Convective Terms

Matrix Solution by Bi-Conjugate Gradient Stabilized (Bi-CGSTAB) Method


VRSIM : Automated Mesh Generator

GeometryGeometry YZYZ--MeshMesh

XZXZ--MeshMesh XYXY--MeshMesh


2/18/2009

20

VRSIM : Graphical User Interface


VRSIM : Applications

Air Flow in a Typical Waiting Room


2/18/2009

21

VRSIM : Applications

Heat Stack Problem Due to Outdoor Units


Contents


Introduction


VRSIM CFD Software





Conclusions


2/18/2009

22


Discretization : -Normalized Variable Formulation (NVF)– GAMMA Diff iDifferencingHigh Order NVF Scheme which satisfy Total Variation Diminishing (TVD) Criterion

Computational EfficiencyArtificial Compressibility TechniqueFull Approximation Storage Multi-gridAgglomeration Technique for Unstructured GridAdaptive Mesh Refinement


Applications

Transonic Flow in Binnie & Green Nozzle


2/18/2009

23

Applications

Transonic Flow in Binnie & Green Nozzle


Applications

RAE2822 Airfoil


2/18/2009

24

Applications

Supersonic Flow Past a Blunt Body


Triple Points

Applications

Supersonic Flow Past a Blunt Body


Triple Points

2/18/2009

25

Contents


Introduction


VRSIM CFD Software




Conclusions




Experimental Facility in UNITEN Shock Tunnel Lab


2/18/2009

26


Experimental Facility in UNITEN Shock Tunnel Lab



1D Sod’s Problem

su

re

(P

a)

5.0E+05

6.0E+05

7.0E+05

8.0E+05

9.0E+05

1.0E+06

ExactCFD

P4= 1000 kPaP1= 100 kPa

N=356

y(

kg

/m

3)

6

7

8

9

10

11

12

ExactCFD

P4 = 1000 kPaP1 = 100 kPa

N = 356

ac

h

0.5

0.6

0.7

0.8

0.9

1

ExactCFD


Distance (m)

Pr

es

s

0 0.25 0.5 0.75 1

1.0E+05

2.0E+05

3.0E+05

4.0E+05

5.0E+05

Distance (m)

De

ns

it

y

0 0.25 0.5 0.75 1

1

2

3

4

5

Distance (m)

Ma

0 0.25 0.5 0.75 1

0

0.1

0.2

0.3

0.4 P4= 1000 PaP1= 100 kPa

N=356

2/18/2009

27


1D Sod’s Problem



Transient High Speed Viscous Flow in Real Shock TubeFlow Direction

Dead Flow Region

Reattachment Point

Shear Layer

(P

a)

5.0E+05

6.0E+05

7.0E+05

0.02

0.025

0.03

se

c]


Time (sec)

Pr

es

su

re

(

0 0.01 0.02 0.03

2.0E+05

3.0E+05

4.0E+05EXPCFD-Angle 5

NX=456NY=21Dia=14 mm

0

0.005

0.01

0.015

Ti

me

[s

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5

Distance [m]X

Y

Z

2/18/2009

28


Transient High Speed Viscous Flow in Real Shock Tube

Temperature Transient



Transient High Speed Viscous Flow in Real Shock TubeComparisons with Experiment and 1D Theoretical Solution

5.5750

Sh

oc

kS

tr

en

gt

hP

2/

P1

3.5

4

4.5

5

TheoreticalCFDMeasured S

ho

ck

sp

ee

d[

m/

s]

600

625

650

675

700

725

TheoreticalCFDMeasured

ck

Ma

ch

1.9

1.95

2

2.05

2.1

2.15


Pressure Ratio P4/P1

S

10 15 20 25 30 35 40 45 50 55

3

Pressure Ratio P4/P110 15 20 25 30 35 40 45 50 55

575

600

Pressure Ratio

Sh

oc

10 15 20 25 30 35 40 45 50 55

1.65

1.7

1.75

1.8

1.85TheoreticalCFDMeasured

2/18/2009

29


Transient High Speed Viscous Flow in Shock TunnelVelocity Transient



Transient High Speed Viscous Flow in Shock TunnelVelocity Transient


2/18/2009

30

Contents


Introduction


VRSIM CFD Software




Conclusions


Two Phase Condensing Flow


Extension to Include the Effect of Two-Phase Condensing Flows of SteamApplication to Cascade of LP Turbine BladeApplication to Cascade of LP Turbine Blade

DRY WET


2/18/2009

31


Application to Cascade of LP Turbine Blade

Contours of Contours of Constant Wetness Constant Wetness FractionFraction


Condensation Starts HereCondensation Starts Here


Application to Cascade of LP Turbine Blade

DRYDRY WETWET


Shock WaveShock Wave CondensationCondensation

2/18/2009

32


Application to Cascade of LP Turbine Blade –Predicted Blade Efficiency Comparisons with Experiment

Inlet Conditions Efficiency%

Bladeprofile

FlowCondition

PressureRatio

WetnessLoss

BoundaryLayer Loss

MixingLoss

Shock Loss%profile Condition

PoBar

To-Ts(Po)K

Ratio Loss%

Layer Loss%

Loss% % Prediction

%Experiment

%Supersonic

Dry1.72 - 2.08 - 2.80 0.32 - 96.88 95.00

SupersonicWet

1.72 -7.6 2.08 5.3 2.84 0.44 - 91.42 90.00

SubsonicDry

1.72 - 1.75 - 4.53 0.22 - 95.25 95.00Nozzle-1

Blade

SubsonicWet

1.72 -8.7 1.75 5.5 4.63 0.48 - 89.39 87.00

SupersonicDry

1.27 - 3.10 - 1.31 1.75 0.709 96.23 94.26

SupersonicWet

1.30 -6.67 3.07 6.32 0.74 2.46 0.670 89.82 89.73

Supersonic 1.29 - 2.33 - 1.55 0.96 0.474 97.02 96.23


SupersonicDry

1.29 2.33 1.55 0.96 0.474 97.02 96.23

SupersonicWet

1.30 -6.86 2.31 5.39 1.02 1.87 0.367 91.35 91.48

SonicDry

1.29 - 1.83 - 2.25 1.34 0.131 96.28 96.07

SonicWet

1.31 -6.63 1.83 5.05 2.81 1.26 0.080 90.80 91.08

SubsonicDry

1.29 - 1.48 - 2.37 0.37 - 97.27 97.61

Nozzle-2Blade

SubsonicWet

1.33 -5.29 1.48 1.21 2.19 0.45 - 96.14 96.15

Contents


Introduction


VRSIM CFD Software




Conclusions


Conclusions

2/18/2009

33

Conclusions

CFD has become an indispensible design and analysis tool in industryDevelopment of an indigenous CFD technology andDevelopment of an indigenous CFD technology and expertise is very strategic for the progress of Malaysian industryA significant progress has been achieved towards developing an indigenous CFD software in MalaysiaThe CFD software has been applied to various test ppcases across wide flow regimesThe results shows very good agreement with experimental and other numerical predictions


Moving Forward

Development of general unstructured mesh generator for 3D complex geometryExtension of Normalized Variable Formulation toExtension of Normalized Variable Formulation to general 3D flowsDevelopment of 3D solver based on Lattice Boltzmann Method (LBM)Development of solver for fluid-structure interaction simulation – Collocated Finite Volume MethodDevelopment of solver based on Boundary Element Method (BEM)Development of Mesh-less MethodUtilization of Grid Computing in CFD simulation


2/18/2009

34


Date post:	19-May-2018
Category:	Documents
Upload:	phamthu
View:	217 times
Download:	2 times

Professorial Lecture Feb 2009 Final Version Notes2 Lecture...Overview of CFD Introduction CFD &...

Documents