Megafires: Earth -scale Challange

8/16/2019 Megafires: Earth -scale Challange

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@pintofscience #pint16

Megafires: an Earth-Scale Challenge

Guillermo ReinDepartment of

Mechanical Engineering

1. What is fire?2. Types of fire?3. Largest fires on Earth?

TOC


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What is Engineering?

“engineering underpins every aspect of our lives”Lord Browne, Royal Academy of Engineering.

“Scientists seek to understand what is,

engineers seek to create what never was”Theodore von Kármán (1881 – 1963), aerospace pioneer.

Engineers make a better world by shapingtechnology. And science is their powerhouse.


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Wild-Urban Interface (WUI)

Built Environment Natural Environment

What is Fire Safety Engineering?We make the world safer from fire: protect people,it property and the environment .


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We help design safer high-rise buildings

Travelling Fires (accelerated video): Development of bending forces anddeformation in beams as the fire spread along a floor of a multi-storey building



What is fire?Accidental Combustion: reaction between fuel and

oxidizer releasing chemical energy in the form ofheat (exothermic).

“the greatest single discovery in human history”

Isaac Asimov (1942-1992)



Fire Science 70,000 years ago

JH Matternes



Fort McMurray, Alberta, Canada


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Fort McMurray, Alberta, Canada


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Large because of its fire power?

Safety threat?

Suppression costs?

Burnt area?

I argue that it should be total fuel consumed

Megafire refers to a large wildfire


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But Fort McMurray is still burning


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15% carbon emissions ≈ EU footprint

Largest fires on Earth are smouldering peatlands

“Smoke Blankets Indonesia” NASA Goddard

Equivalent to 13-40% of man-made global carbon emissions

(and not account for by IPCC yet)


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@pintofscience #pint16NASA TOMS satellite

The 1997 smouldering peat fires in Borneo releasedbetween 0.8 and 2.6 billion tons of carbon into theatmosphere. That is equivalent to 13 to 40 % of all

emissions from burning fossil fuels


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@pintofscience #pint16 National Geographic 2008 / AP Photo/MODIS

2008 - The Evans Road fire, North Carolinaburned for 7 months

Worst drought on record 16,500 ha (twice average) 1 m deep into the soil Stopped by flooding


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3D fires: lateral and in-depth spread

320

0 3

t S S dt mt m ld t

t gsmoulderin ρ π == ∫ )(


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Sign at sports facility,Singapore. Russia, 2010

Haze – Long-term widespreadepisodes of poor air quality


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Fire and Natural Fuels

10 years 1,000 years 1,000,000 years 300,000,000 years

Peat: Decayed vegetation matter,forming layers up to 30 m deep


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Previous to combustion of a solid fuel: pyrolysis

Then, two possible oxidation paths:

a) If oxidation of pyrolysate (gas-phase) → flaming

b) If oxidation of char (solid- phase) → smouldering

gasesotherOHCOO(gas)Pyrolyzate 222 ++→+

Ash(solid)Char(gas)Pyrolyzate (solid)Fuel ++→

AshgasesotherOHCO(gas)O(solid)Char 222 +++→+

Types of fire? Types of combustio n


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Smoldering combustion is theslow, low temperature,flameless burning of porousfuels.

It is especially common in:Natural fuels: biomass, peat, duff,litter, wood, coal.

Synthetic fuels: cellulose,polyurethane foam.


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video speeded up 600 times: 1 s video = 10 min experiment

Smouldering spread30x30 cm tray setup with 5 cm layer of peat

Top view, Visual camera Top view, Infrared camera


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Earth Scale: Positive feedback in climate change


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1. Scientific understanding is poorflaming ≠ smouldering

2. NON-EXISTENT MITIGATION TECHNOLOGIES catastrophic dimensions

3. TOPIC FRAGMENTED AMONG DISCIPLINES combustion ∩ geoscience ∩ ecology

HAZE: Europe’s chance to pioneer technologies against smouldering

TOP CHALLENGES We turn these challengesinto grand opportunities.

Provide the fundamental science and thetechnology to tackle smouldering megafires.

Knowledge-based pathways to prevention,detection, monitoring and suppression.

Accurate riskmaps

Warning systemsbased on gas and spectral signatures

U d IR i l f d


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Grupo de Dr Zarco-Tejada, CSIC

Unmanned IR airplane foundsurface heating on four areas


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Take home messages

Accidental combustion: reaction between fuel andoxidizer releasing chemical energy in the form of heat.

Fire Engineers make the world safer from fire: protectpeople, it property and the environment.

Smouldering combustion burns the char of organic fuelsand leads to the largest fires on Earth.

Research Opportunity: Average 15% carbonemissions = Footprint of EU = Footprint ofWorldwide fleet of cars (and not account for inglobal budgets).


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AdvanceKnowledge

FosterInnovation

DevelopNew Talent

Sponsors:

State of the art

Scale

lab

field scalekm

cm

m

CERIB


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The Burning Mountain, Australia, Feb 2014

after 2001 WTC collapse


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after 2001 WTC collapse…

“the longest-burning structural fire in

history” (New Scientist, Dec. 2001)


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Five days after collapseOne month after collapse

Photographs from the Office for Technology, New York State, 2001

Five months after collapseLongest-burning building fire: 5 months

O Revealer


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O-Revealer

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Schematic of smouldering fire spread over a minefield in peatland(a) before reaching the mines, and (b) after spreading over the mines.

O Revealer: Landmine clearance by fire


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@pintofscience #pint16 35

SB-33 antipersonnel plastic mine

O-Revealer: Landmine clearance by fire

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Megafires: Earth -scale Challange

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