SST-SAS在小分离流动数值模拟中的表现测试

Behavior of SST-SAS for Mild Airfoil Trailing-Edge Separation

作为一种新型RANS/LES混合方法,基于SST湍流模型的尺度自适应模拟方法(SST-SAS)近来得到越来越多的关注。以AS239翼型最大升力点临界状态为数值模拟算例,测试了SST-SAS在小分离流动中的表现并与SST-DES和SST-DDES进行比较。结果显示,在翼型表面边界层处SAS能够克服DES中出现的网格诱导分离,得到了类似DDES延迟RANS的效果,同时在翼型尾迹区明显降低了小分离流动中强烈的灰区效应影响,尾迹涡结构比DDES更加清晰细密。

The Scale-Adaptive Simulation （ SAS ） based on SST turbulence model is more and more popular as a new hybrid RANS/LES method. The flow around AS239 airfoil at the maximum lift condition is simulated by SST-SAS to test its behavior in the mild separation. Compared with results from SST-DES and SST-DDES, SST-SAS on one hand overcomes the Grid Induced Separation （ GIS） near the boundary like the delay of RANS in SST-DDES and on the other hand, it decreases the grey area in the wake and gets clearer vortexes and more accurate velocity profile than those obtainable with SST-DDES.