跨音速透平叶栅尾缘劈缝射流气动性能分析

Analysis of the Aerodynamic Performance of the Jet Flow from the Slot at the Trailing Edge of the Guide Blades of a Transonic Turbine Cascade

基于定常RANS方程,采用Spalart-Allmaras（S-A）湍流模型,数值模拟某跨音速导叶尾缘劈缝射流的定常流动结构,分析尾缘劈缝射流对尾缘激波结构、尾迹流动特性及叶栅气动性能的影响。研究表明：开缝射流显著降低尾缘压力面侧燕尾波强度,并使激波在相邻叶片吸力面入射点向上游移动;当叶栅出口马赫数小于1.35时射流使吸力面燕尾波强度减弱,而达到1.35后射流使该侧激波强度增大;在不同出口马赫数下射流均能降低叶栅动能损失。

Based on the constant RANS equation,the Spalart-Allmaras （S-A） turbulent flow model was adopted to numerically simulate the constant flow configuration of the jet flow from the slot at the trailing edge of the guide blades in a transonic cascade and analyze the influence of the jet flow from the slot at the trailing edge on the shock wave configuration, wake flow characteristics and aerodynamic performance of the cascade. It has been found that the jet flow from the slot can significantly lower the intensity of the dovetail waves at the pressure side at the trailing edge and make the incident point of the shock wave on the suction surface of the neighboring blade shift to the upstream. When the Mach number at the outlet of the cascade is less than 1.35, the jet flow under discussion will make the intensity of the dovetail waves on the suction surface become weakened and after the Mach number at the outlet of the cascade had reached 1.35 ,the jet flow will force the said intensity of the shock wave to increase. The jet flow at various Mach numbers at the outlet will invariably reduce the kinetic energy loss of the cascade.