LARGE EDDY SIMULATION OF A TURBULENT NONPREMIXED JET FLAME USING A FINITE-RATE CHEMISTRY MODEL

Large eddy simulation (LES) is conducted of a turbulent piloted nonpremixed methane jet flame. This flame has been studied experimentally at Sandia National Laboratories. The subgrid scale (SGS) closure in LES is based on the scalar filtered mass density function (SFMDF) methodology. The SFMDF is essentially the mass weighted probability density function (PDF) of the SGS scalar quantities. The SFMDF is obtained from an exact transport equation which provides a closed form for the chemical reaction effects. The unclosed terms in this equation are modeled by a set of stochastic differential equations (SDEs). The SDEs are solved by a hybrid finite-difference/Lagrangian Monte Carlo procedure. This flame exhibits little local extinction. In previous work, the instantaneous flame composition was related to the mixture fraction based on the flamelet model at low strain rates. In the present work, this assumption is relaxed, and a direct solver is employed for finite-rate chemistry. The results via this method agree favorably with those obtained experimentally. The end result is an accurate and affordable method for the LES of realistic turbulent flames.

[1]  J. Elgin.  The Fokker-Planck Equation: Methods of Solution and Applications , 1984 .

[2]  Peyman Givi,et al.  Some Current Issues In The Analysis Of Reacting Shear Layers: Computational Challenges , 1992 .

[3]  R. Borghi.  Turbulent combustion modelling , 1988 .

[4]  Stephen B. Pope,et al.  Computations of turbulent combustion: Progress and challenges , 1991 .

[5]  G. D. Byrne,et al.  VODE: a variable-coefficient ODE solver , 1989 .

[6]  Denis Veynante,et al.  Turbulent combustion modeling , 2002, VKI Lecture Series.

[7]  S. Pope,et al.  Velocity filtered density function for large eddy simulation of turbulent flows , 2000 .

[8]  P. Givi.  Model-free simulations of turbulent reactive flows , 1989 .

[9]  E. O'brien,et al.  The probability density function (pdf) approach to reacting turbulent flows , 1980 .

[10]  S. Pope.  Lagrangian PDF Methods for Turbulent Flows , 1994 .

[11]  Stephen B. Pope,et al.  Large eddy simulation of a turbulent nonpremixed piloted methane jet flame (Sandia Flame D) , 2004 .

[12]  K. Vahala.  Handbook of stochastic methods for physics, chemistry and the natural sciences , 1986, IEEE Journal of Quantum Electronics.

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

[14]  S. Karlin,et al.  A second course in stochastic processes , 1981 .

[15]  Á. Aldama.  Filtering Techniques for Turbulent Flow Simulation , 1990 .

[16]  Robert J. Kee,et al.  CHEMKIN-III: A FORTRAN chemical kinetics package for the analysis of gas-phase chemical and plasma kinetics , 1996 .

[17]  J. Ferziger,et al.  Improved turbulence models based on large eddy simulation of homogeneous, incompressible, turbulent flows , 1983 .

[18]  B. Geurts,et al.  Realizability conditions for the turbulent stress tensor in large-eddy simulation , 1994, Journal of Fluid Mechanics.

[19]  Stephen B. Pope,et al.  Filtered mass density function for large-eddy simulation of turbulent reacting flows , 1999, Journal of Fluid Mechanics.

[20]  P. Sagaut.  Large Eddy Simulation for Incompressible Flows , 2001 .

[21]  T. Poinsot,et al.  Theoretical and numerical combustion , 2001 .

[22]  J Mathew,et al.  Filtered density function for large eddy simulation of turbulent reacting flows , 2008 .

[23]  R. S. Barlow,et al.  Raman-Rayleigh-LIF measurements of temperature and species concentrations in the Delft piloted turbulent jet diffusion flame , 2000 .

[24]  R. Barlow,et al.  Effects of turbulence on species mass fractions in methane/air jet flames , 1998 .

[25]  Stephen B. Pope,et al.  PDF calculations of turbulent nonpremixed flames with local extinction , 2000 .

[26]  C. W. Gardiner,et al.  Handbook of stochastic methods - for physics, chemistry and the natural sciences, Second Edition , 1986, Springer series in synergetics.

[27]  Stephen B. Pope,et al.  Computationally efficient implementation of combustion chemistry using in situ adaptive tabulation , 1997 .

[28]  J. Philip Drummond,et al.  Suppression and Enhancement of Mixing in High-Speed Reacting Flow Fields , 1994 .

[29]  Stephen B. Pope,et al.  Velocity-scalar filtered mass density function for large eddy simulation of turbulent reacting flows , 2007 .

[30]  Stephen B. Pope,et al.  Velocity-scalar filtered density function for large eddy simulation of turbulent flows , 2003 .

[31]  Chung King Law,et al.  An augmented reduced mechanism for methane oxidation with comprehensive global parametric validation , 1998 .

[32]  Thomas M. Eidson,et al.  Numerical simulation of the turbulent Rayleigh–Bénard problem using subgrid modelling , 1985, Journal of Fluid Mechanics.