CFD Analysis of Turbulent Combustion Processes by a Stochastic Approach

Abstract

General overview of the stochastic approach for turbulent non-uniform combustion is described. The stochastic approach combined with a CFD calculation with the conventional turbulence model is discussed. At each point in a turbulent flow field, the variation of some scalar-variables are statistically described by the joint probability density function (joint-PDF), and the velocity is expressed using a conventional turbulence model. The transport equation of this joint-PDF is calculated by a finite-difference method in convection and turbulent diffusion and by the stochastic model in molecular mixing. In addition, simulation results using this stochastic approach are presented for the mixing process in a high-speed jet and the combustion process in a natural gas HCCI engine.