湍流-化学双时间尺度PDF湍流燃烧模型及其检验

The numerical simulation of high-precision aero-engine combustion chamber repaires an accurate de-scription of the strong nonlinear interaction between turbulence and detailed chemical reaction mechanism.The large eddy simulation method(LES)using the probability density function turbulence combustion model(PDF)is expected to achieve this aim.So the impact of chemical reactions needs to be considered in the existing PDF mo-lecular mixing model.In this paper,based on the previous research,the mixing time scale in the molecular mix-ing model was modified to form three kinds of turbulence-chemistry two-time-scale PDF model.The methane jet Flame D and Flame E of Sandia laboratory were simulated using the Aero Engine Combustor Simulation Code(AECSC)based on the LES-PDF method.The transient results show that the instantaneous flow state of the jet flame can be predicted by all the three models.The scalar statistical prediction results were compared with the experimental data.The results show that the calculation results of the PDF model with arithmetic mean modifica-tion are the closest to the experimental data.The two-time-scale PDF model needs further examination.