Monte Carlo Calculations of Turbulent Diffusion Flames

Calculations of turbulent diffusion flames are presented and compared with experimental data. In the calculation procedure, the mean continuity and momentum equations are solved by a finite-difference method, and the k-epsilon turbulence model is used to model the Reynolds stresses. The conserved-scalar approach is used so that the local, instantaneous, thermochemical properties of the flame are uniquely related to a single conserved scalar f(x, t)-the mixture fraction. A modelled transport equation for the probability density function (pdf) of f is solved by a Monte Carlo method. The results of calculations are compared with experimental data for three turbulent flows: an inert methane jet; a hydrogen/air diffusion flame; and a hydrogen-argon/air diffusion flame. In general there is good agreement between calculated and measured quantities, including pdf's. Numerical tests of the Monte Carlo method are also reported. These demonstrate the convergence of the method and provide an estimate of the statistical error.