Extinction Simulation of a Diffusion FlameEstablished in Microgravity

presented by Guillaume Legros(1)

( legros@lcd.ensma.fr )

in collaboration withA. Fuentes(1), B. Rollin(1), P. Joulain(1),

J.P. Vantelon(1), and J.L. Torero(2)

(1) Laboratoire de Combustion et de Détonique (UPR 9028 du CNRS) – Poitiers (France)(2) School of Engineering and Electronics, The University of Edinburgh – Edinburgh (United

Kingdom)

4th International Conference on Computational Heat and Mass Transfer Cachan, May, 19th, 2005

Plausible Spacecraft Fire Scenario:

INTRODUCTION

INTRODUCTION

EXPERIMENT

SIMULATION

COMPARISON

CONCLUSIONS

condensed fuel

oxidizer blowingvelocity: Vox

Plausible Spacecraft Fire Scenario:

INTRODUCTION

condensed fuel

oxidizer blowingvelocity: Vox

extinction !

INTRODUCTION

EXPERIMENT

SIMULATION

COMPARISON

CONCLUSIONS

Investigating extinction:

O2 level

oxidizer balance gaz

VOX

condensed fuel nature

INTRODUCTION

need of valuable numerical simulations

INTRODUCTION

EXPERIMENT

SIMULATION

COMPARISON

CONCLUSIONS

Investigating extinction:

O2 level

oxidizer balance gaz

VOX

condensed fuel nature

INTRODUCTION

need of valuable numerical simulations

INTRODUCTION

EXPERIMENT

SIMULATION

COMPARISON

CONCLUSIONS

Investigating extinction:

O2 level

oxidizer balance gaz

VOX

condensed fuel nature

INTRODUCTION

need of valuable numerical simulations

INTRODUCTION

EXPERIMENT

SIMULATION

COMPARISON

CONCLUSIONS

Investigating extinction:

O2 level

oxidizer balance gaz

VOX

condensed fuel nature

INTRODUCTION

need of valuable numerical simulations

INTRODUCTION

EXPERIMENT

SIMULATION

COMPARISON

CONCLUSIONS

Investigating extinction:

O2 level

oxidizer balance gaz

VOX

condensed fuel nature

INTRODUCTION

need of valuable numerical simulationsfor steady-state phenomena

INTRODUCTION

EXPERIMENT

SIMULATION

COMPARISON

CONCLUSIONS

Experimental Environment:

Parabolic flights

microgravity duration = 22 s

a parabola every 2 minutes

EXPERIMENTAL PROCEDURE

easy ignition

+ fast transition to steady-state

INTRODUCTION

EXPERIMENTEnvironmentMeasurement

SIMULATION

COMPARISON

CONCLUSIONS

EXPERIMENTAL PROCEDURE

easy ignition

+ fast transition to steady-state

INTRODUCTION

EXPERIMENTEnvironmentMeasurement

SIMULATION

COMPARISON

CONCLUSIONS

Experimental Environment:

Parabolic flights

microgravity duration = 22 s

a parabola every 2 minutes

EXPERIMENTAL PROCEDURE

easy ignition

+ fast transition to steady-state

INTRODUCTION

EXPERIMENTEnvironmentMeasurement

SIMULATION

COMPARISON

CONCLUSIONS

Experimental Environment:

Parabolic flights

microgravity duration = 22 s

a parabola every 2 minutes

EXPERIMENTAL PROCEDURE

easy ignition

+ fast transition to steady-state

INTRODUCTION

EXPERIMENTEnvironmentMeasurement

SIMULATION

COMPARISON

CONCLUSIONS

Experimental Environment:

Parabolic flights

microgravity duration = 22 s

a parabola every 2 minutes

EXPERIMENTAL PROCEDURE

easy ignition

+ fast transition to steady-state

INTRODUCTION

EXPERIMENTEnvironmentMeasurement

SIMULATION

COMPARISON

CONCLUSIONS

Experimental Environment:

EXPERIMENTAL PROCEDURE

easy ignition

+ fast transition to steady-state

oxidizer blowingvelocity: Vox

ethylene injectionvelocity: VF

1 cm

INTRODUCTION

EXPERIMENTEnvironmentMeasurement

SIMULATION

COMPARISON

CONCLUSIONS

Experimental Measurement:

EXPERIMENTAL PROCEDURE

INTRODUCTION

EXPERIMENTEnvironmentMeasurement

SIMULATION

COMPARISON

CONCLUSIONS

Experimental Measurement:

CH* chemiluminescence

Iflame(λ=431 nm) α ICH* [1]

[1] Berg et al. (2000)

EXPERIMENTAL PROCEDURE

INTRODUCTION

EXPERIMENTEnvironmentMeasurement

SIMULATION

COMPARISON

CONCLUSIONS

Experimental Measurement:

CH* chemiluminescence

ICH* α volumetric combustion rate [2]

[2] McManus et al. (1995)

EXPERIMENTAL PROCEDURE

INTRODUCTION

EXPERIMENTEnvironmentMeasurement

SIMULATION

COMPARISON

CONCLUSIONS

Experimental Measurement:Map by CH* chemiluminescence

EXPERIMENTAL PROCEDURE

oxidizer blowingvelocity: Vox

ethylene injectionvelocity: VF

1 cm

INTRODUCTION

EXPERIMENTEnvironmentMeasurement

SIMULATION

COMPARISON

CONCLUSIONS

Experimental Measurement:Map by CH* chemiluminescence

EXPERIMENTAL PROCEDURE

oxidizer blowingvelocity: Vox

1 cm

α map of volumetric combustion rate

INTRODUCTION

EXPERIMENTEnvironmentMeasurement

SIMULATION

COMPARISON

CONCLUSIONS

Validating numerical extinction:

O2 level = 35%

oxidizer balance gaz = N2

fuel = C2H4

Vox = parameter

comparison based on volumetric combustion rate

NUMERICAL PROCEDURE

INTRODUCTION

EXPERIMENT

SIMULATIONGoalToolDomain

COMPARISON

CONCLUSIONS

Validating numerical extinction:

O2 level = 35%

oxidizer balance gaz = N2

fuel = C2H4

Vox = parameter

comparison based on volumetric combustion rate

NUMERICAL PROCEDURE

INTRODUCTION

EXPERIMENT

SIMULATIONGoalToolDomain

COMPARISON

CONCLUSIONS

Validating numerical extinction:

O2 level = 35%

oxidizer balance gaz = N2

fuel = C2H4

Vox = parameter

comparison based on volumetric combustion rate

NUMERICAL PROCEDURE

INTRODUCTION

EXPERIMENT

SIMULATIONGoalToolDomain

COMPARISON

CONCLUSIONS

Validating numerical extinction:

O2 level = 35%

oxidizer balance gaz = N2

fuel = C2H4

Vox = parameter

comparison based on volumetric combustion rate

NUMERICAL PROCEDURE

INTRODUCTION

EXPERIMENT

SIMULATIONGoalToolDomain

COMPARISON

CONCLUSIONS

Validating numerical extinction:

O2 level = 35%

oxidizer balance gaz = N2

fuel = C2H4

Vox = parameter

comparison based on the mapof volumetric combustion rate

NUMERICAL PROCEDURE

INTRODUCTION

EXPERIMENT

SIMULATIONGoalToolDomain

COMPARISON

CONCLUSIONS

Numerical Tool:Variant of Fire Dynamics Simulator (FDS):

transient 3D Navier-Stokes equations (low Mach number approximation)

allowing large density and temperature changes Direct Numerical Simulation mixture fraction / finite kinetics – no soot model Radiative Transfer Equation (non-scattering approximation)

RTE

Finite Volume Method Wideband model ( H2O + CO2 )

NUMERICAL PROCEDURE

INTRODUCTION

EXPERIMENT

SIMULATIONGoalToolDomain

COMPARISON

CONCLUSIONS

Numerical Tool:Variant of Fire Dynamics Simulator (FDS):

transient 3D Navier-Stokes equations (low Mach number approximation)

allowing large density and temperature changes Direct Numerical Simulation mixture fraction / finite kinetics – no soot model Radiative Transfer Equation (non-scattering approximation)

RTE

Finite Volume Method Wideband model ( H2O + CO2 )

NUMERICAL PROCEDURE

INTRODUCTION

EXPERIMENT

SIMULATIONGoalToolDomain

COMPARISON

CONCLUSIONS

Numerical Tool:Variant of Fire Dynamics Simulator (FDS):

transient 3D Navier-Stokes equations (low Mach number approximation)

allowing large density and temperature changes Direct Numerical Simulation mixture fraction / finite kinetics – no soot model Radiative Transfer Equation (non-scattering approximation)

RTE

Finite Volume Method Wideband model ( H2O + CO2 )

NUMERICAL PROCEDURE

INTRODUCTION

EXPERIMENT

SIMULATIONGoalToolDomain

COMPARISON

CONCLUSIONS

Numerical Tool:Variant of Fire Dynamics Simulator (FDS):

transient 3D Navier-Stokes equations (low Mach number approximation)

allowing large density and temperature changes Direct Numerical Simulation mixture fraction / finite kinetics – no soot model Radiative Transfer Equation (non-scattering approximation)

RTE

Finite Volume Method Wideband model ( H2O + CO2 )

NUMERICAL PROCEDURE

INTRODUCTION

EXPERIMENT

SIMULATIONGoalToolDomain

COMPARISON

CONCLUSIONS

Numerical Tool:Variant of Fire Dynamics Simulator (FDS):

transient 3D Navier-Stokes equations (low Mach number approximation)

allowing large density and temperature changes Direct Numerical Simulation mixture fraction / finite kinetics – no soot model Radiative Transfer Equation (non-scattering approximation)

RTE

Finite Volume Method Wideband model ( H2O + CO2 )

NUMERICAL PROCEDURE

INTRODUCTION

EXPERIMENT

SIMULATIONGoalToolDomain

COMPARISON

CONCLUSIONS

Numerical Tool:Variant of Fire Dynamics Simulator (FDS):

transient 3D Navier-Stokes equations (low Mach number approximation)

allowing large density and temperature changes Direct Numerical Simulation mixture fraction / finite kinetics – no soot model Radiative Transfer Equation (non-scattering approximation)

RTE

Finite Volume Method Wideband model ( H2O + CO2 )

NUMERICAL PROCEDURE

INTRODUCTION

EXPERIMENT

SIMULATIONGoalToolDomain

COMPARISON

CONCLUSIONS

Methodology:choice of the iso-contour value?

Sum of volumetric

combustion rate

threshold

Max

10 % of Max

Iso-contour value

COMPARISON

INTRODUCTION

EXPERIMENT

SIMULATION

COMPARISONMethodologyStand-off distanceFlame lengthSoot role

CONCLUSIONS

Stand-off Distance:iso-contours

VOX

VF

COMPARISON

INTRODUCTION

EXPERIMENT

SIMULATION

COMPARISONMethodologyStand-off distanceFlame lengthSoot role

CONCLUSIONS

Flame Length:

COMPARISON

INTRODUCTION

EXPERIMENT

SIMULATION

COMPARISONMethodologyStand-off distanceFlame lengthSoot role

CONCLUSIONS

Flame length:

INTRODUCTION

INTRODUCTION

CURSUS

ENSEIGNEMENTCadreExpériences

RECHERCHECadreExpériences

CONCLUSIONS

Discrepancy Evolution:

COMPARISON

INTRODUCTION

EXPERIMENT

SIMULATION

COMPARISONMethodologyStand-off distanceFlame lengthSoot role

CONCLUSIONS

Discrepancy Evolution:

VOX=150 mm.s-1 VOX=250 mm.s-1

(b)

(a)

characteristic residence time

VOX

COMPARISON

INTRODUCTION

EXPERIMENT

SIMULATION

COMPARISONMethodologyStand-off distanceFlame lengthSoot role

CONCLUSIONS

This study achieved :

coupling of radiative transfer and finite kinetics, leading to flame extinction simulation, thus better flame shape predictions

highlight the soot keyrole in the extinction at the flame trailing edge

This study needs to achieve :

incorporation of a soot model

CONCLUSIONS

INTRODUCTION

EXPERIMENT

SIMULATION

COMPARISON

CONCLUSIONS

This study achieved :

coupling of radiative transfer and finite kinetics, leading to flame extinction simulation, thus better flame shape predictions

highlight the soot keyrole in the extinction at the flame trailing edge

This study needs to achieve :

incorporation of a soot model

CONCLUSIONS

INTRODUCTION

EXPERIMENT

SIMULATION

COMPARISON

CONCLUSIONS

Enjeu: utilisation de l’échelle des temps de résidence pour l’étude de l’extinction de la réaction par les pertes radiatives

Techniques expérimentales

Analyse dimensionnellede la couche-limite réactive:

Foxsox

sf VV~,

,

ττ

Résultats:

fraction volumique de suie mesurée et rapportée à FoxVV

expérimental

théorie

Techniques expérimentalesEchéance: caractérisation des conditions ( Tsuie , fsuie ) dans la zone de quenching Incandescence Induite par Laser Emission/Absorptio

n Modulée

étalonnage

z y

x

z y

x

Enjeu: appréhender la dynamique de l’interaction flamme non- prémélangée / particules

Techniques expérimentales

touverture caméra

flash laser

Résultats:

Echéance:couplage de techniques pour cerner le couplage aérodynamique des flammes / formation des suies

LIF

LII

intensité induite

APPENDIX

X=0,1 X=0,5 X=0,98 X=1,1

Vox =100 mm.s-1

flxX =

Computational Domain:

NUMERICAL PROCEDURE

INTRODUCTION

EXPERIMENT

SIMULATIONGoalToolDomain

COMPARISON

CONCLUSIONS

oijkI

z = 0:u = 0T = Tw

εw = 0,95

y = 0:grad u = 0T = Ta

ε = 1

x = 0:u = Vox

T = Ta

ε = 1

y = ymax:grad u = 0T = Ta

ε = 1

z = zmax:grad u = 0T = Ta

ε = 1

x = xmax:grad u = 0T = Ta

ε = 1

g = 0