Numerical Simulation Of Passive Scalar In Turbulence Diffusion Combustion

Numerical simulation of turbulent combustion is a very important method of studying combustion. Modeling turbulent combustion is a formidable task, since there is a strong interaction between turbulent mixing and chemical reaction, which results in the difficulties to express the averaged reaction rates in terms of the averaged values of scalars. How to describe the interaction accurately is a key part of turbulent combustion.At present the popular turbulent diffusion combustion models include Probability Density Function (PDF), Conditional Moment Closure (CMC) and so on. In these models there is a basic parameter- passive scalar, so we can make use of the scalar as a key parameter to describe turbulent combustion. It is mixture fraction in turbulent diffusion combustion.Most present studies of scalar are developed from k-εequation method ,which is based on the assumption of Boussinesq .So the numerical simulation of the scalar is derived from isotropy, it cannot express the anisotropy of turbulence. This study is used with second-order closure -- Reynold Stress Model to simulate the scalar in turbulent diffusion combustion to predict accurately.The Simplified-PDF model is used to describe turbulent combustion process. The Simplified-PDF model can reasonably simulate the complicated chemical reactions of turbulent diffusion combustion.Numerical simulation of turbulent bluff-body jets used with above models is presented in the paper. The simulated results are compared with experiments results given by Sandia laboratory, and the good agreement shows that second-order-moment model can well model the limited and detail chemical kinetics and enhance the combustion model precision.