多种修正的SA模型对二维分离流动的预测性能

Performance of SA Model With Various Modifications in Predicting Two-Dimensional Separated Flow

采用6种不同SA模型及其与QCR2000和QCR2013方法的混合模型对低速驼峰流动进行数值模拟,并与实验及LES模拟结果对比,以分析各湍流模型对二维分离流动的预测性能。结果表明:各种SA模型普遍存在过大预测分离、速度亏损恢复较慢、雷诺切应力峰值过小等问题。各种模型给出的分离区形态基本一致,原始SA模型对分离大小的预测与实验结果符合得最好。线性涡黏模型采用QCR修正后对分离区长度的预测变差,但是对雷诺切应力模拟的准确程度有所提高。

In this paper,six different SA models and their combinations with the QCR2000 and QCR2013 methods are used for simulating the low-speed hump flow.Referring to the experiment and LES data,the performance of these turbulence models in predicting two-dimensional separated flow is evaluated.It is found that all SA models over predict the separation size thus the recovery of axial velocity loss is delayed.Also,the peak value of Reynolds shear stress is largely underestimated.Although the separation structure given by tested models basically keeps the same,the original SA model fits the best with the experiment in terms of separation size among them.After applying QCR corrections to the linear eddy viscosity models,the length of separation region gets even larger while the Reynolds shear stress is simulated more accurately.