低反力度跨声速转子的叶顶喷气扩稳数值研究

为进一步提高低反力度压气机的稳定工作范围，以某三级低反力度高负荷压气机首级跨声速转子为研究对象，借助三维数值模拟方法，进行了叶顶喷气扩稳研究，分析讨论了叶顶喷气提升低反力度压气机转子稳定性的机理，并探讨了不同喷气轴向位置对扩稳效果及气动性能的影响。结果表明：叶顶喷气通过削弱叶顶泄漏涡和通道激波的相互作用，抑制了转子近失速工况下泄漏涡的破碎，消除了叶顶通道的大面积堵塞，拓宽了转子的稳定工作边界；随着喷嘴的位置从叶顶前缘处沿轴向上游移动，转子的失速裕度提升量呈现出先增大后减小的趋势，综合扩稳效果和对压气机总性能参数的影响，最佳喷气轴向位置为叶顶前缘上游转子5%叶顶轴向弦长处；叶顶喷气改变了转子气动参数的径向分布，降低了转子上15%叶高范围内的负荷，同时也使得其它叶高区域的负荷提升。

Numerical Investigation of Stability Enhancement with Tip Air Injection in a Low-Reaction Transonic Rotor

In order to further improve the stable working range of the low-reaction compressor, the effect of tip air injection on extending stall margin was numerically studied in the first-stage transonic rotor of a three-stage low-reaction high-load compressor. Stability-enhancing mechanism and the impact of axial positions of injectors on stability enhancement and aerodynamic performance of the rotor were discussed. The results show that tip air injection suppresses the breaking of the leakage vortex under the near-stall condition of the rotor by weakening the interaction between the tip leakage vortex and the passage shock wave and eliminating the large-area blockage of the blade tip passage, which result in widening the rotor"s stable operating margin. As the injector moves axially upstream from the leading edge of the blade tip, the amount of increase in stability enhancement presents a trend of increasing first and then decreasing. Considering the effect of stall margin improvement and the overall rotor performance parameters, the optimal injection axial position is 5% of the rotor axial chord length upstream of the leading edge of the blade tip. Tip air injection changes the radial distribution of the rotor aerodynamic parameters and reduces the compression work of the outer 15% span.