亚音轴流压气机叶尖微喷气扩稳机理探讨

Investigation on Stability Enhancement of Micro Tip Injection for a Subsonic Axial Compressor

为了探索叶顶微喷气对轴流压气机的稳定性影响,本文以西北工业大学某高负荷亚音速轴流压气机的孤立转子为研究对象,采用实验和数值模拟相结合的方法,研究了叶顶微喷气对压气机的扩稳效果和作用机理.研究结果表明,高速喷气降低了转子叶顶载荷,将压气机的流量裕度拓宽了5.6个百分点。相对于原实壁工况,喷气之后在原失稳边界流量上,削弱了由叶尖二次涡所诱导出的流场非定常脉动,而该非定常脉动与突尖形失速先兆的形成密切相关,由此推迟了压气机失稳。且存在临界攻角,随着节流程度增加,当叶顶攻角达到与原实壁工况相对应的失稳攻角后,压气机再度失稳。

In this paper, to explore the effect on subsonic axial compressor stability of micro tip injection, experiment combined with 5 passage unsteady numerical simulation was conducted to study stability enhancement effect and mechanism of micro tip injection for a high load subsonic isolated rotor located at Northwestern Polytechnieal University. Results show that micro tip injection can reduce tip load and the stall margin is extended by 5.6 percentage points. Compared to original condition, when the rotor works at near stall condition of non-injection ones, flow field unsteady fluctuation induced by tip second vortex is weakened evidently with micro tip injection. There is a critical attack angle and when the attack angle reaches critical value which is same as the non-injection ones, the compressor rotor stalls again.