提高Spalart-Allmaras湍流模型对分离模拟能力的研究

Investigation on improving the capability of predicting separation of Spalart-Allmaras turbulence model

为了提高Spalart-Allmaras湍流模型对分离的模拟能力,提出了两种改进方法.第一种是根据模型特点而提出的提高对雷诺正应力的模拟精度,第二种是基于湍流特性的理论分析而提出的对模型生成与耗散的关系进行修正.研究结果表明:第一种方法,由于没有明显提高对雷诺正应力的模拟精度,从而并没有提高模型对分离流动的模拟能力;第二种方法,由于改进了模型对强非平衡湍流的模拟能力,从而明显地提高了模型对分离流动的模拟精度.

Two methods were applied to improve the capability of predicting separation of Spalart-Allmaras turbulence model. One was to improve the capability of predicting Reynolds normal stress based on the property of Spalart-Allmaras turbulence model, the other one was to calibrate the production coefficient based on the non-equilibrium of turbulence in sepa- ration region. The results show that= the first one contributes little to improving the capability of prediction separation of Spalart-Allmaras turbulence model, because the capability of predicting Reynolds normal stresses is not improved considerably; while the second one improves obviously the capability of prediction separation of Spalart-Allmaras turbulence model, because the capability of S-A model in capturing the non-equilibrium turbulence is improved notably.