Subgrid scale laminar flamelet model for partially premixed combustion and its application to backdraft simulation

Flame spread after air is suddenly introduced to a vitiated compartment in backdraft is between non-premixed and premixed flame spread under a ventilation-controlled condition. And it is necessary, but difficult to numerically simulate it. In this paper, an attempt of backdraft simulation is introduced. Numerical models including a subgrid scale laminar flamelet model and a partially premixed model are imbedded in FDS3.0 source code for backdraft simulation. Some significant fire characteristics reported in previous backdraft experiments can be seen in the numerical results. It is also indicated that these combined models can be used to predict the partially premixed combustion and fire phenomena under ventilation-controlled conditions.

[1]  Alan R. Kerstein,et al.  Linear-eddy modelling of turbulent transport. Part 3. Mixing and differential molecular diffusion in round jets , 1990, Journal of Fluid Mechanics.

[2]  Wenguo Weng,et al.  Nonlinear analysis of the backdraft phenomenon in room fires , 2004 .

[3]  Ulrich Schumann,et al.  Coherent structure of the convective boundary layer derived from large-eddy simulations , 1989, Journal of Fluid Mechanics.

[4]  Alan R. Kerstein,et al.  A linear-eddy model of turbulent scalar transport and mixing , 1988 .

[5]  Frederick W. Williams,et al.  The development and mitigation of backdraft: a real-scale shipboard study , 1999 .

[6]  Kevin B. McGrattan,et al.  Fire dynamics simulator (ver-sion 3) technical reference guide , 2001 .

[7]  Wang Qing.  A model of backdraft phenomenon in building fires , 2002 .

[8]  Herbert E. Huppert,et al.  Entrainment into two-dimensional and axisymmetric turbulent gravity currents , 1996, Journal of Fluid Mechanics.

[9]  K. Bray,et al.  Partially premixed flamelets in LES of nonpremixed turbulent combustion , 2002 .

[10]  W. Weng,et al.  Study on salt water modeling of gravity currents prior to backdrafts using flow visualization and digital particle image velocimetry , 2002 .

[11]  Weigang Zhang,et al.  Turbulence statistics in a fire room model by large eddy simulation , 2002 .

[12]  D. Lentini.  Assessment of The Stretched Laminar Flamelet Approach For Nonpremixed Turbulent Combustion , 1993 .

[13]  H. Baum,et al.  Large eddy simulations of smoke movement , 1998 .

[14]  Feng Gao,et al.  A large‐eddy simulation scheme for turbulent reacting flows , 1993 .

[15]  J. X. Wen,et al.  The use of a laminar flamelet approach in the large eddy simulation of flame structure at the base of a pool fire , 2001 .

[16]  C. Carter,et al.  Observations on the leading edge in lifted flame stabilization , 1999 .

[17]  Robert J. Kee,et al.  The computation of stretched laminar methane-air diffusion flames using a reduced four-step mechanism , 1987 .

[18]  Wolfgang Polifke,et al.  An Efficient Computational Model for Premixed Turbulent Combustion at High Reynolds Numbers Based on a Turbulent Flame Speed Closure , 1997 .

[19]  Wenguo Weng,et al.  Mitigation of backdraft with water mist: A reduced‐scale experimental study , 2003 .

[20]  Norbert Peters,et al.  Partially premixed turbulent flame propagation in jet flames , 1994 .

[21]  Lizhong Yang,et al.  Experimental study of back-draft in a compartment with openings of different geometries , 2003 .

[22]  N. Peters.  Laminar diffusion flamelet models in non-premixed turbulent combustion , 1984 .

[23]  Sharath S. Girimaji,et al.  ANALYSIS AND MODELING OF SUBGRID SCALAR MIXING USING NUMERICAL DATA , 1995 .

[24]  J. Smagorinsky,et al.  GENERAL CIRCULATION EXPERIMENTS WITH THE PRIMITIVE EQUATIONS , 1963 .

[25]  Andrew W. Cook,et al.  Subgrid-scale modeling for turbulent reacting flows , 1998 .

[26]  W. Weng,et al.  Critical condition of backdraft in compartment fires: a reduced-scale experimental study , 2003 .

[27]  Glenn P. Forney,et al.  Fire Dynamics Simulator (Version 3): Technical Reference Guide (NISTIR 6783) , 2001 .

[28]  Joel H. Ferziger,et al.  Status of Large Eddy Simulation: Results of a Workshop , 1997 .

[29]  Sébastien Candel,et al.  Numerical Study of Unsteady Turbulent Premixed Combustion: Application to Flashback Simulation , 1998 .

[30]  J. Riley,et al.  A subgrid model for equilibrium chemistry in turbulent flows , 1994 .

[31]  K. McGrattan,et al.  Numerical and experimental gravity currents related to backdrafts , 1999 .

[32]  F. Ducros,et al.  Subgrid scale variance and dissipation of a scalar field in large eddy simulations , 2001 .

[33]  N. Peters,et al.  An experimental and numerical study of a laminar triple flame , 1998 .

[34]  Stephen B. Pope,et al.  The statistical theory of turbulent flames , 1979, Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences.

[36]  Andrew W. Cook,et al.  A laminar flamelet approach to subgrid-scale chemistry in turbulent flows , 1997 .

[37]  Fuchen Jia,et al.  The prediction of fire propagation in enclosure fires , 1997 .