反叶片角向缝机匣处理影响轴流压气机性能的机理

采用试验和非定常数值模拟方法研究了反叶片角向缝机匣处理对亚声速轴流压气机性能的影响.试验与数值计算结果均指出反叶片角向缝机匣处理后，转子在降低12%左右最大等熵效率的基础上获得30.1%左右的失速裕度改进量.详细的转子叶顶流场分析表明反叶片角向缝机匣处理改善了叶顶间隙泄漏流动，消除了实体壁机匣时叶顶通道低速泄漏流形成的堵塞，因此转子稳定性得以提高.同时转子叶片与处理缝的相对位置变化会影响处理缝的扩稳能力.处理缝中回流、处理缝形成的喷射流与叶顶通道主流的相互作用都造成较大的流动损失，进而使转子等熵效率降低.反叶片角向缝机匣处理前移约55%叶顶轴向弦长的数值研究结果表明，与反叶片角向缝机匣处理比较，反叶片角向缝机匣处理前移获得的失速裕度改进量降低约10.4%，但等熵效率的恶化程度降低近64%. 

Mechanisms of affecting the performance of axial-flow compressor with athwart blade-angle slots casing treatment

Influences of athwart blade-angle slots casing treatment on the performance of subsonic axial-flow compressor were investigated with the experimental and unsteady numerical simulation methods. The experimental and unsteady numerical calculation results showed that the rotor gained about 30.1% stall margin improvement at the cost of decreasing about 12% peak isentropic efficiency of smooth wall casing with athwart blade-angle slots casing treatment. The detailed analysis of rotor blade tip flow-field indicated that the tip clearance leakage flow was improved with athwart blade-angle slots casing treatment and the blockage created by low energy clearance leakage flow in blade tip was removed in blade tip with smooth wall casing,so the stability of rotor was improved. It was found that the ability to improve rotor stability of slot was affected by the relative position of blade and slot, and moreover, back flow in slot and the interaction of injecting flow brought by slot and blade tip mainstream resulted in serious flow loss, leading to decline of the rotor isentropic efficiency. The numerical calculation results also showed that the stall margin improvement and the level of decreasing isentropic efficiency reduced about 10.4% and 64% respectively by making the athwart blade-angle slots casing treatment move forward about the 55% axial chord of blade tip.