DES模型在压气机亚音转子中的应用探讨

APPLICATION OF DETACHED EDDY SIMULATION IN SUBSONIC COMPRESSOR ROTOR

本文运用分离涡模拟(DES)方法研究了不同工况下压气机亚音转子的流动情况,分析了其时均与瞬时流场中顶部间隙泄漏流动和根部角区的流动分离。通过与S-A模型计算结果的对比表明,DES模型在模拟顶部泄漏流动及二次泄漏、泄漏流在转子下游与尾迹的干涉时能够捕捉到更强的旋涡结构,在模拟转子根部角区的分离时也能获得更为丰富的流动现象.对不同工况的DES计算表明负荷的上升会使泄漏涡形成的位置向上游移动,从而导致并加剧二次流动,并对叶栅下游泄漏涡与尾迹的干涉产生影响。对设计工况下瞬时流场的分析表明,泄漏涡在叶栅下游体现出周期性的强弱变化,近叶根分离区也体现出明显的非定常性。

The flowfield in a subsonic compressor rotor at different operation conditions was investigated using DES （Detached Eddy Simulation）. The tip leakage flow and flow separation near hub in both time-averaged flowfleld and instantaneous flowfleld were analyzed. Comparison of DES model and S-A model indicates that DES model can capture more intensive vortex structure when simulating tip leakage flow and double leakage, as well as the interaction between the leakage fluid and wake downstream of the rotor passage. Furthermore, DES model can predict more complicated flow at the separate region near hub. DES simulation of the rotor flowfleld at different operation conditions shows the influence of loading on tip leakage flow. The origin point of leakage vortex moves upstream when the loading increases. Double leakage can be seen at design point and higher loading, while it＇s not seen at lower loading. Instantaneous flowflelds show the unsteadiness of tip leakage vortex. Alternating regions of higher and lower loss is found along the time-averaged leakage vortex trajectory. Obvious unsteadiness is also shown in the separate region near hub.