激励参数对合成射流控制压气机流动分离的影响

Effects of Actuation Parameters on Flow Separation Control in Compressor with Synthetic Jets

关键词:  合成射流  激励参数  高负荷压气机叶栅  流动分离  气动性能

Key words:  Synthetic jets  Actuation parameters  Highly loaded compressor cascade  Flow separation  Aerodynamic performance

摘要:

对吸力面施加合成射流激励的高负荷压气机静叶栅展开数值模拟，系统地研究不同激励参数对单缝合成射流改善叶栅气动性能的影响，并探索分段式合成射流控制流动分离的有效性。研究结果表明，单缝合成射流对栅内流动的作用效果主要取决于两个因素:射流切向动量注入带来的气动性能改善与射流输运过程的附加流动损失。单缝合成射流具有较为宽广的有效频率范围，当激励频率等于主流流过叶型的频率且射流满足有效激励动量要求时，对叶栅气动性能的改善效果最佳，总压损失降低约14.26%。分段式合成射流能够较好地适应不同叶高处分离起始点沿轴向变化对最佳流动控制位置的要求，在不增加有效射流面积的前提下可较单缝射流更为有效地控制流动分离，此时的损失降低幅度高达15.84%，从另外一个角度证实了激励位置对于非定常激励的重要性。

Abstract:

A highly loaded compressor stator cascade with synthetic jet actuators mounted on the blade suction side is numerically investigated. The effects of actuation parameters on the performance of cascade with single-slit synthetic jet are systematically studied，and the effectiveness of segment synthetic jet on separation control is validated. Simulation results indicate that the single-slit synthetic jet has a two-way effect on the flow field: the performance improvements by the tangential momentum injection and the additional flow losses associated with the jet. Within a broad frequency range，as the jet momentum reaching its effective level，a better control effect can be obtained under the frequency of the main flow passing through the airfoil. A reductions of 14.26% for the total pressure loss coefficient can be gained under the best condition. Moreover，the segment synthetic jet can adapt to the requirements for the optimal actuated position of flow separation at different blade height，which varies along the axial direction. Compared with the single-slit synthetic jet，the flow separation can be effectively suppressed without enlarging the jet area，corresponding to a remarkable loss reductions of up to 15.84%. Additionally，the importance of forcing position is highlighted for the unsteady actuation.