双重时间步方法在非定常流场模拟中的应用

在非定常流动的数值模拟中引入隐式双重时间步方法 ,并对2种经典的非定常流动现象进行计算 ,取得令人满意的结果,证明双重时间步方法具有较好的精度和较快的收敛速度。应用此方法对压气机动静叶非定常流场进行研究,结果表明高损失区集中在边界层附近及尾迹区;上游叶片排尾迹对下游叶片通道流动影响很大,它增加边界层损失,并在通道中与主流发生强烈掺混,最终使得出口流场及损失分布较为均匀。

PREDICTION OF 3-D UNSTEADY FLOW USING IMPLICIT DUAL TIME STEP APPROACH

The application of an implicit dual time step algorithm for the prediction of 3 D unsteady flow is presented. It is proved that the dual time step algorithm is efficient in the simulation of unsteady flow with the prediction of vortex shedding over circular cylinders and shock buffeting over bicircular airfoils. The dual time step procedure is used to simulate the unsteady flow through a one stage compressor, and the result reveals that there are complex unsteady flow structures in the blade passage.