On the relation between the conditional moment closure and unsteady flamelets

We consider the relation between the conditional moment closure (CMC) and the unsteady flamelet model (FM). The CMC equations were originally constructed as global equations, while FM was derived asymptotically for a thin reaction zone. The recent tendency is to use FM-type equations as global equations. We investigate the possible consequences and suggest a new version of FM: coordinate-invariant FM (CIFM). Unlike FM, CIFM complies with conditional properties of the exact transport equations which are used effectively in CMC. We analyse the assumptions needed to obtain another global version of FM: representative interactive flamelets (RIF), from original FM and demonstrate that, in homogeneous turbulence, one of these assumptions is equivalent to the main CMC hypothesis.

[1]  C. Gibson.  Fine Structure of Scalar Fields Mixed by Turbulence. II. Spectral Theory , 1968 .

[2]  C. Gibson.  Fine Structure of Scalar Fields Mixed by Turbulence. I. Zero‐Gradient Points and Minimal Gradient Surfaces , 1968 .

[3]  R. W. Bilger,et al.  Turbulent flows with nonpremixed reactants , 1980 .

[4]  Influence of turbulence on the formation of high nonequilibrium concentrations of atoms and free radicals in diffusion flames , 1982 .

[5]  N. Peters.  Local Quenching Due to Flame Stretch and Non-Premixed Turbulent Combustion , 1983 .

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

[7]  S. Pope.  PDF methods for turbulent reactive flows , 1985 .

[8]  Stephen B. Pope,et al.  The importance of time-dependent flame structures in stretched laminar flamelet models for turbulent jet diffusion flames , 1989 .

[9]  V. R. Kuznetsov,et al.  Turbulence and combustion , 1990 .

[10]  A. Klimenko,et al.  Multicomponent diffusion of various admixtures in turbulent flow , 1990 .

[11]  Fabian Mauß,et al.  A lagrangian simulation of flamelet extinction and re-ignition in turbulent jet diffusion flames , 1991 .

[12]  Robert W. Bilger,et al.  Conditional moment closure for turbulent reacting flow , 1993 .

[13]  James J. Riley,et al.  INVESTIGATION OF CLOSURE MODELS FOR NONPREMIXED TURBULENT REACTING FLOWS , 1994 .

[14]  Heinz Pitsch,et al.  Numerical Investigation of Soot Formation and Oxidation Under Diesel Engine Conditions , 1995 .

[15]  A. Klimenko,et al.  Note on the conditional moment closure in turbulent shear flows , 1995 .

[16]  Heinz Pitsch,et al.  Three-Dimensional Modeling of NOx and Soot Formation in DI-Diesel Engines Using Detailed Chemistry Based on the Interactive Flamelet Approach , 1996 .

[17]  N. Peters,et al.  Unsteady flamelet modeling of turbulent hydrogen-air diffusion flames , 1998 .

[18]  A. Klimenko,et al.  Conditional moment closure for turbulent combustion , 1999 .

[19]  H. Pitsch,et al.  Large-eddy simulation of a turbulent piloted methane/air diffusion flame (Sandia flame D) , 2000 .