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采用三个线性和七个非线性涡粘性湍流模式,对二维非对称喷管中的不可压缩分离流进行了研究。通过将数值计算结果和实验结果进行比较,对有关的湍流模式进行了评估和分析。计算结果表明,非线性模式的模化系数与平均流动应变不变量以及旋转不变量有关,反映了湍流的各向异性,比线性模式优越得多。另外,所有线性/非线性涡粘性湍流模式不能够捕捉流动的非定常分离过程。
Three linear and seven nonlinear eddy-viscosity turbulence models are used to investigate the incompressible separation flow in a two-dimensional asymmetric nozzle. By comparing the numerical results with the experimental results, the relevant turbulence models were evaluated and analyzed. The calculation results show that the modal coefficient of nonlinear model is related to the average invariance of flow strain and the invariant of rotation, which reflects the anisotropy of turbulence and is much superior to the linear model. In addition, all linear / nonlinear eddy turbulent models can not capture the unsteady flow separation.