PhD Proposal - December 2008

NUMERICAL INVESTIGATIONS OF GASEOUS SPHERICAL DIFFUSION FLAMES Advisory Committee: Assistant Professor Peter B. Sunderland , Advisor and Chair Associate Professor Gregory J. Jackson Associate Professor André W. Marshall Associate Professor Arnaud Trouvé Professor James G. Quintiere , Dean’s representative By Vivien Lecoustre, PhD student Dissertation Proposal

Acknowledgments ,[object Object],[object Object]

Propose of the study ,[object Object],[object Object],[object Object]

Presentation Outline ,[object Object],[object Object],[object Object],[object Object]

Why 1-D Spherical diffusion flame? ,[object Object],[object Object],[object Object],[object Object]

Characteristics of Spherical Diffusion Flame ,[object Object],[object Object],[object Object],Reduced Damköhler number Adiabatic: Radiative loss: At Steady State: (Matalon et al. )

Modeling Spherical Diffusion Flames (1/2) ,[object Object],[object Object],[object Object]

Modeling Spherical Diffusion Flames (2/2) ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

[object Object],[object Object],[object Object],[object Object],Presentation Outline

Soot: Generalities ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],Important Pathways to first ring: C 3 H 3 + C 3 H 3 -> Benzene + H+H C 3 H 3 + C 2 H 2 -> C 5 H 5 C 5 H 5 + CH 3 -> Benzene + H+H Growth of PAH by HACA mechanism: A i + H -> A i- + H 2 A i- + C 2 H 2 -> A i C 2 H 2 A i C 2 H 2 + C 2 H 2 -> A i+1

Soot: Background ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Objectives ,[object Object],[object Object],[object Object],[object Object],[object Object]

Experimental ,[object Object],[object Object],[object Object],18% C 2 H 4  28% O 2 O 2  13% C 2 H 4 Inverted convection Normal convection

blue=min orange=max For all flames, HRR is 71 W .Sooting limit occurs at 2 s. Sooting limit flames Flame Ambient X C2H4,0 X O2,0 Z st t res , s T ad , K T f 2s K 1 Oxidizer 1 0.22 0.065 2.72 2390 1545 2 Oxidizer 0.6 0.21 0.102 1.63 2326 1492 3 Oxidizer 0.31 0.21 0.18 0.91 2226 1479 4 Oxidizer 0.25 0.23 0.225 0.665 2238 1498 5 Oxidizer 0.18 0.28 0.333 0.351 2306 1592 6 Oxidizer 0.17 0.29 0.353 0.33 2308 1593 7 Oxidizer 0.11 0.5 0.586 0.11 2381 1795 8 Oxidizer 0.11 0.8 0.685 0.044 2528 2057 9 Oxidizer 0.15 1 0.661 0.024 2740 2262 10 Fuel 1 0.13 0.041 0.059 1847 1581 11 Fuel 0.8 0.13 0.051 0.072 1835 1549 12 Fuel 0.6 0.13 0.066 0.086 1814 1515 13 Fuel 0.21 0.25 0.277 0.119 2274 1689 14 Fuel 0.19 0.3 0.336 0.122 2370 1736 15 Fuel 0.15 0.5 0.509 0.148 2539 1802 16 Fuel 0.12 0.8 0.666 0.279 2578 1729 17 Fuel 0.13 1 0.692 0.249 2670 1814

Method ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Temporal evolution ,[object Object],[object Object],[object Object]

Structure of sooting limit flames ,[object Object],[object Object],[object Object]

Results : T 0.6 vs. t res at 2 seconds ,[object Object],[object Object]

Results : T 0.6 vs. Z st ,[object Object],[object Object]

Time scale and scalar dissipation rate ,[object Object],[object Object],[object Object],[object Object]

Mixture fraction ,[object Object],[object Object],[object Object]

Flame structure (Flame 10) ,[object Object],[object Object],[object Object],[object Object],[object Object]

Critical local C/O ratio ,[object Object],[object Object],[object Object],[object Object]

T where C/O = 0.51 ,[object Object],[object Object],[object Object]

Conclusions ,[object Object],[object Object],[object Object],[object Object]

Micro-Flames: Background ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Experimental results ,[object Object],[object Object],[object Object],[object Object],H 2 /Air: H 2 /O 2 :

Objectives and method ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

H 2 /Air flame, r b = 3.175 mm Moderate flow rate: r b = 3.175 mm T flame = 2300 K r flame = 22 cm HRR = 1275 W χ flame = 5.2 10 -6 s -1 ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

H 2 /Air flame, r b = 75 μ m and 1 μ m Low flow rate: r b = 75 μ m T flame = 1290 K r flame = 200 μ m HRR = 0.41 W χ flame = 0.98 s -1 ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],r b = 1 μ m T flame = 1290 K r flame = 180 μ m HRR = 0.40 W χ flame = 1.18 s -1 75 μ m burner 1 μ m burner

Effects of mass flow rate and burner size (1/2) ,[object Object],[object Object],[object Object],[object Object]

Effects of mass flow rate and burner size (2/2) ,[object Object],[object Object],[object Object],[object Object],[object Object]

Summary ,[object Object],[object Object],[object Object],[object Object],[object Object]

Soot (1/3) New kinetic model: ABF ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],C 4 H 3 +C 2 H 2 -> Phenyl C 4 H 5 +C 2 H 2 -> Benzene + H C 3 H 3 + C 3 H 3 -> Benzene C 3 H 3 + C 2 H 2 -> C 5 H 5 C 5 H 5 + CH 3 -> Benzene + H + H C 5 H 5 +C 5 H 5 -> naphthalene + H + H

Soot (2/3): Preliminary results with ABF model. ,[object Object],[object Object],[object Object],[object Object]

Soot (3/3) Effects of the early presence of soot? ,[object Object],[object Object],[object Object],[object Object],[object Object]

Management : Soot project ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Management: H 2 /Air flames ,[object Object],[object Object],[object Object]

PhD Proposal - December 2008

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PhD Proposal - December 2008