射流对压气机叶栅分离流控制的数值研究

Numerical Investigation on Controlling Separated Cascade Flows by Using Jets

现代先进轴流压气机级负荷不断提高的发展趋势导致流动分离日益严重。借助数值模拟分别对非定常射流和定常射流进行了参数优化研究。结果表明:基于射流的主动流动控制能有效弱化或消除流动分离,不同射流方式存在不同的最优射流参数(射流方向、位置、速度和频率等),这就为利用射流控制轴流压气机分离流动的工程应用奠定了一定的理论基础。

Separated flow is studied on a 2D cascade using steady and unsteady jets. The time-mean jeted flow rates are not more than 1% of the inlet mass flow rate. The results show that, by means of adding jets on the suction surface, the separated flow could be effectively controlled and the time-mean performance of flow filed could be remarkably improved. The optimal jet direction varies with each type of jets. The most effective jet location is at a distance upstream of the time-mean separation point which distinguishes from that of unsteady jet. For a fixed slot width, the effectiveness of injection associates with the balance between injection velocity, or jeted flow rate, and blockage. There is an optimal frequency for the unsteady jet.