S弯扩压器中四种湍流模型的比较

采用Realizableκ-ε,S-A(Spalart-Allmaras),SST(Shear stress transport剪切应力输运),RSM(Reynolds stress equation model雷诺应力模型)四种湍流模型对S弯扩压器内的分离流动进行了模拟,分析了不同湍流模型对计算结果的影响.将不同轴向位置的表面压力系数、分离区的大小、马赫数等三个量的实验值与计算值进行了比较,结果表明:分离区湍流模型对表面压力分布影响较大,未分离区不同湍流模型模拟精度相当;S-A模型对分离区的模拟较保守,RSM模型对分离的模拟精度较高,SST与RSM模拟结果很接近;各湍流模型计算的高速区域均比实验值大.扩压器的平均总压恢复系数受湍流模型影响不大,和实验结果吻合较好. 

Comparison of four turbulence models in diffusing S-duct

Four turbulence models: Realizable κ-ε,S-A(Spalart-Allmaras),SST(Shear stress transport) and RSM(Reynolds stress equation model),were compared by simulating separated flow in a diffusing S-duct.The numerical results show the capability of each turbulence model in dealing with separation.Before separation,the predicted results agree well with experiment for four models,but in separated region,the turbulence model has important effect in simulating separation.SST model is compared to RSM in simulating separation and pressure coefficient,however not as clearly as RSM.S-A model under predict the separation and the separated region is smaller than experiment.Mach number is higher than experimental data for four models.Pressure recoveries are similar for different models,and are within 0.7% agreement with experimental data.