关键词: 紊流燃烧;模型;数值分析

Abstract: The k-ε-g turbulent combustion model is widely applied to many combustion systems by using model coefficients* which are different for various investigators. It fact, it is very important for better modelling combustion process to determine model coefficients Cg1, Cg2, CR and mean square fluctuation of fuel concentration g. Calculations and experiments of combustion recirculating flow behind flame-holders are conducted. Predicted profiles of flow parameters are obtained by using different values of model coefficients and expressions of g. Experiments on gas temperature and combustion efficiency are preformed in a simulated afterburner with bluff-body flame-holders. Good agreement of predicted values with experimental data shows that model coefficients are closely related to reaction rate. Among them, the influence of CR is significant. An expression of CR, which accounts for the effect of temperature, is proposed, g obtained from solving g differential equation is more rational than its algebric expression used for given initial value. The coefficients appearing in transport terms are relatedby Cgt=2/σf and cg2=2.0.

Key words: Turbulent combustionj Model;Numerical analysis