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Extinction Simulation of a Diffusion Flame Established in Microgravity presented by Guillaume Legros (1) ( legros@lcd.ensma.fr ) in collaboration with A. 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) 4 th International Conference on Computational Heat and Mass Transfer Cachan, May, 19 th, 2005
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Plausible Spacecraft Fire Scenario: INTRODUCTION EXPERIMENT SIMULATION COMPARISON CONCLUSIONS condensed fuel oxidizer blowing velocity: V ox
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Plausible Spacecraft Fire Scenario: INTRODUCTION condensed fuel oxidizer blowing velocity: V ox extinction ! INTRODUCTION EXPERIMENT SIMULATION COMPARISON CONCLUSIONS
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Investigating extinction: O 2 level oxidizer balance gaz V OX condensed fuel nature INTRODUCTION need of valuable numerical simulations INTRODUCTION EXPERIMENT SIMULATION COMPARISON CONCLUSIONS
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Investigating extinction: O 2 level oxidizer balance gaz V OX condensed fuel nature INTRODUCTION need of valuable numerical simulations INTRODUCTION EXPERIMENT SIMULATION COMPARISON CONCLUSIONS
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Investigating extinction: O 2 level oxidizer balance gaz V OX condensed fuel nature INTRODUCTION need of valuable numerical simulations INTRODUCTION EXPERIMENT SIMULATION COMPARISON CONCLUSIONS
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Investigating extinction: O 2 level oxidizer balance gaz V OX condensed fuel nature INTRODUCTION need of valuable numerical simulations INTRODUCTION EXPERIMENT SIMULATION COMPARISON CONCLUSIONS
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Investigating extinction: O 2 level oxidizer balance gaz V OX condensed fuel nature INTRODUCTION need of valuable numerical simulations for steady-state phenomena INTRODUCTION EXPERIMENT SIMULATION COMPARISON CONCLUSIONS
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Experimental Environment: Parabolic flights microgravity duration = 22 s a parabola every 2 minutes EXPERIMENTAL PROCEDURE easy ignition + fast transition to steady-state INTRODUCTION EXPERIMENT Environment Measurement SIMULATION COMPARISON CONCLUSIONS
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EXPERIMENTAL PROCEDURE easy ignition + fast transition to steady-state INTRODUCTION EXPERIMENT Environment Measurement SIMULATION COMPARISON CONCLUSIONS
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Experimental Environment: Parabolic flights microgravity duration = 22 s a parabola every 2 minutes EXPERIMENTAL PROCEDURE easy ignition + fast transition to steady-state INTRODUCTION EXPERIMENT Environment Measurement SIMULATION COMPARISON CONCLUSIONS
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Experimental Environment: Parabolic flights microgravity duration = 22 s a parabola every 2 minutes EXPERIMENTAL PROCEDURE easy ignition + fast transition to steady-state INTRODUCTION EXPERIMENT Environment Measurement SIMULATION COMPARISON CONCLUSIONS
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Experimental Environment: Parabolic flights microgravity duration = 22 s a parabola every 2 minutes EXPERIMENTAL PROCEDURE easy ignition + fast transition to steady-state INTRODUCTION EXPERIMENT Environment Measurement SIMULATION COMPARISON CONCLUSIONS
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Experimental Environment: EXPERIMENTAL PROCEDURE easy ignition + fast transition to steady-state oxidizer blowing velocity: V ox ethylene injection velocity: V F 1 cm INTRODUCTION EXPERIMENT Environment Measurement SIMULATION COMPARISON CONCLUSIONS
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Experimental Measurement: EXPERIMENTAL PROCEDURE INTRODUCTION EXPERIMENT Environment Measurement SIMULATION COMPARISON CONCLUSIONS
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Experimental Measurement: CH * chemiluminescence I flame (λ=431 nm) α I CH* [1] [1] Berg et al. (2000) EXPERIMENTAL PROCEDURE INTRODUCTION EXPERIMENT Environment Measurement SIMULATION COMPARISON CONCLUSIONS
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Experimental Measurement: CH * chemiluminescence I CH* α volumetric combustion rate [2] [2] McManus et al. (1995) EXPERIMENTAL PROCEDURE INTRODUCTION EXPERIMENT Environment Measurement SIMULATION COMPARISON CONCLUSIONS
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Experimental Measurement: Map by CH* chemiluminescence EXPERIMENTAL PROCEDURE oxidizer blowing velocity: V ox ethylene injection velocity: V F 1 cm INTRODUCTION EXPERIMENT Environment Measurement SIMULATION COMPARISON CONCLUSIONS
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Experimental Measurement: Map by CH* chemiluminescence EXPERIMENTAL PROCEDURE oxidizer blowing velocity: V ox 1 cm α map of volumetric combustion rate INTRODUCTION EXPERIMENT Environment Measurement SIMULATION COMPARISON CONCLUSIONS
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Validating numerical extinction: O 2 level = 35% oxidizer balance gaz = N 2 fuel = C 2 H 4 V ox = parameter comparison based on volumetric combustion rate NUMERICAL PROCEDURE INTRODUCTION EXPERIMENT SIMULATION Goal Tool Domain COMPARISON CONCLUSIONS
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Validating numerical extinction: O 2 level = 35% oxidizer balance gaz = N 2 fuel = C 2 H 4 V ox = parameter comparison based on volumetric combustion rate NUMERICAL PROCEDURE INTRODUCTION EXPERIMENT SIMULATION Goal Tool Domain COMPARISON CONCLUSIONS
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Validating numerical extinction: O 2 level = 35% oxidizer balance gaz = N 2 fuel = C 2 H 4 V ox = parameter comparison based on volumetric combustion rate NUMERICAL PROCEDURE INTRODUCTION EXPERIMENT SIMULATION Goal Tool Domain COMPARISON CONCLUSIONS
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Validating numerical extinction: O 2 level = 35% oxidizer balance gaz = N 2 fuel = C 2 H 4 V ox = parameter comparison based on volumetric combustion rate NUMERICAL PROCEDURE INTRODUCTION EXPERIMENT SIMULATION Goal Tool Domain COMPARISON CONCLUSIONS
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Validating numerical extinction: O 2 level = 35% oxidizer balance gaz = N 2 fuel = C 2 H 4 V ox = parameter comparison based on the map of volumetric combustion rate NUMERICAL PROCEDURE INTRODUCTION EXPERIMENT SIMULATION Goal Tool Domain COMPARISON CONCLUSIONS
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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 ( H 2 O + CO 2 ) NUMERICAL PROCEDURE INTRODUCTION EXPERIMENT SIMULATION Goal Tool Domain COMPARISON CONCLUSIONS
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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 ( H 2 O + CO 2 ) NUMERICAL PROCEDURE INTRODUCTION EXPERIMENT SIMULATION Goal Tool Domain COMPARISON CONCLUSIONS
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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 ( H 2 O + CO 2 ) NUMERICAL PROCEDURE INTRODUCTION EXPERIMENT SIMULATION Goal Tool Domain COMPARISON CONCLUSIONS
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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 ( H 2 O + CO 2 ) NUMERICAL PROCEDURE INTRODUCTION EXPERIMENT SIMULATION Goal Tool Domain COMPARISON CONCLUSIONS
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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 ( H 2 O + CO 2 ) NUMERICAL PROCEDURE INTRODUCTION EXPERIMENT SIMULATION Goal Tool Domain COMPARISON CONCLUSIONS
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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 ( H 2 O + CO 2 ) NUMERICAL PROCEDURE INTRODUCTION EXPERIMENT SIMULATION Goal Tool Domain COMPARISON CONCLUSIONS
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Methodology: choice of the iso-contour value? Sum of volumetric combustion rate threshold Max 10 % of Max Iso-contour value COMPARISON INTRODUCTION EXPERIMENT SIMULATION COMPARISON Methodology Stand-off distance Flame length Soot role CONCLUSIONS
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Stand-off Distance: iso-contours V OX VFVF COMPARISON INTRODUCTION EXPERIMENT SIMULATION COMPARISON Methodology Stand-off distance Flame length Soot role CONCLUSIONS
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Flame Length: COMPARISON INTRODUCTION EXPERIMENT SIMULATION COMPARISON Methodology Stand-off distance Flame length Soot role CONCLUSIONS
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Flame length: INTRODUCTION CURSUS ENSEIGNEMENT Cadre Expériences RECHERCHE Cadre Expériences CONCLUSIONS
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Discrepancy Evolution: COMPARISON INTRODUCTION EXPERIMENT SIMULATION COMPARISON Methodology Stand-off distance Flame length Soot role CONCLUSIONS
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Discrepancy Evolution: V OX =150 mm.s -1 V OX =250 mm.s -1 characteristic residence time V OX COMPARISON INTRODUCTION EXPERIMENT SIMULATION COMPARISON Methodology Stand-off distance Flame length Soot role CONCLUSIONS
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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
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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
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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 dimensionnelle de la couche-limite réactive: Résultats: fraction volumique de suie mesurée et rapportée à expérimental théorie
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Techniques expérimentales Echéance:caractérisation des conditions ( T suie, f suie ) dans la zone de quenching Incandescence Induite par Laser Emission/Absorption Modulée étalonnage z y x z y x
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Enjeu: appréhender la dynamique de l’interaction flamme non- prémélangée / particules Techniques expérimentales t ouverture caméra flash laser Résultats: Echéance:couplage de techniques pour cerner le couplage aérodynamique des flammes / formation des suies LIF LII intensité induite
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APPENDIX X=0,1X=0,5X=0,98X=1,1 V ox =100 mm.s -1
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Computational Domain: NUMERICAL PROCEDURE INTRODUCTION EXPERIMENT SIMULATION Goal Tool Domain COMPARISON CONCLUSIONS
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z = 0: u = 0 T = T w w = 0,95 y = 0: grad u = 0 T = T a = 1 x = 0: u = V ox T = T a = 1 y = y max : grad u = 0 T = T a = 1 z = z max : grad u = 0 T = T a = 1 x = x max : grad u = 0 T = T a = 1 g = 0
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