组合型机匣处理提高轴流压气机稳定性的机理

用全通道非定常计算方法研究了轴向倾斜缝、自适应机匣处理及两者形成的组合型机匣处理对亚声速轴流式转子稳定工作范围的影响,结果表明:轴向倾斜缝、自适应机匣处理及组合型机匣处理取得的综合裕度改进量分别为12.86%,16.47%及22.72%,其中组合型机匣处理扩稳效果最强,自适应机匣处理次之.通过详细地分析压气机内部流场表明,组合型机匣处理削弱了叶片吸力面气流分离带来的不良影响.从喷气装置流出的高速气流抑制了叶顶间隙泄漏流从相邻叶片叶顶前缘溢出的现象,部分叶片通道受到轴向倾斜缝的作用,泄漏流线被抽吸入缝中,也能抑制前缘溢流的产生.

Mechanism of improvement on axial-flow compressor stability with assembled casing treatment

Influences of the stability of subsonic axial-flow compressor were investigated by full-annulus unsteady numerical method with axial skewed slot casing treatment(CT),self recirculation casing treatment and assembled casing treatment respectively. Assembled casing treatment was composed of axial skewed slot and self recirculation casing treatment. The numerical results show that the ability of assembled casing treatment to improve the rotor steady operating range is the best, followed by self recirculation casing treatment. Compressor could gain 12.86%,16.47% and 22.72% stall margin improvements with three kinds of casing treatment. The fundamental flow mechanism was obtained by detailed analysis of the flow-filed in rotor passage. The analytic results indicate that the bad effect made by flow separation is weakened with assembled casing treatment, and high velocity flow discharged from injecting part can restrain the tip clearance leakage flow spillage from adjacent tip passage at leading edge. The leakage flow is also sucked into axial skewed, preventing the occurrence of leading edge spilling flow.