On recontamination and directionalbias problems in Monte Carlo simulation of PDF turbulence models
Abstract
Turbulent combustion can not be simulated adequately by conventional moment closure turbulence models. The difficulty lies in the fact that the reaction rate is in general an exponential function of the temperature, and the higher order correlations in the conventional moment closure models of the chemical source term can not be neglected, making the applications of such models impractical. The probability density function (pdf) method offers an attractive alternative: in a pdf model, the chemical source terms are closed and do not require additional models. A grid dependent Monte Carlo scheme was studied, since it is a logical alternative, wherein the number of computer operations increases only linearly with the increase of number of independent variables, as compared to the exponential increase in a conventional finite difference scheme. A new algorithm was devised that satisfies a restriction in the case of pure diffusion or uniform flow problems. Although for nonuniform flows absolute conservation seems impossible, the present scheme has reduced the error considerably.
 Publication:

Center for Modeling of Turbulence and Transition (CMOTT). Research Briefs: 1990
 Pub Date:
 October 1991
 Bibcode:
 1991cmtt.rept...66H
 Keywords:

 Algorithms;
 Computational Grids;
 Monte Carlo Method;
 Probability Density Functions;
 Reaction Kinetics;
 Turbulence Models;
 Combustion;
 Computers;
 Difference Equations;
 Diffusion;
 Exponential Functions;
 Finite Difference Theory;
 Nonuniform Flow;
 Turbulence;
 Uniform Flow;
 Fluid Mechanics and Heat Transfer