Abstract: The study was to investigate the method of stability enhancement to control effectively endwall stall in an axial flow compressor. The coupled design took advantage of slot-type casing treatment and tip injection, and the effects on compressor performance of slot length, location and angle were parametrically studied. The flow mechanism of stability improvement and the effect on compressor efficiency were analyzed for the ‘coupled casing treatment’ in the unsteady simulation. The results show that compressor stability margin is improved by 18% with a penalty of 0.21% on compressor efficiency at the design point, and the compressor efficiency is improved slightly at the operating conditions of lower mass flow rates. The slot length is the key to the compressor performance, and the maximum length should not exceed 50% of the axial chord length of the blade tip. The influence of the slot position and slot angle are limited. There are two types of flow circulation in the ‘coupled casing treatment’, i.e. the inner circulation in slots and the circulation from slots to injectors. The two circulations can depress effectively the tip leakage vortex and lower the blade tip loading, which mainly accounts for the stability enhancement. The interaction between the ‘coupled casing treatment’ and compressor is self-adaptive, which reduces its negative effect on the compressor efficiency at the design point and ensures the positive effect on the blade tip blockage. The coupling design of slots and injector has the potential to greatly increase the stall margin of compressor without penalty on compressor efficiency.

摘要： 为了探索可有效控制轴流压气机端壁失速的扩稳方法，将缝式处理机匣与叶顶喷气进行耦合设计，参数化研究了缝的长度、位置和角度对压气机性能的影响，结合非定常数值模拟阐释了“耦合型处理机匣”的扩稳机理以及影响压气机效率的作用机制。研究结果表明，在“耦合型处理机匣”作用下，压气机失速裕度提高18%，压气机效率在小流量工况略有提高，在设计工况降低0.21%。缝长度是影响压气机性能的关键，其最大长度不应超过叶顶轴向弦长的50%，缝的位置和角度的影响程度有限。“耦合型处理机匣”内存在缝内循环和由缝到喷嘴间的循环两种主要流动形式，这两种循环在有效控制叶顶泄漏涡的同时降低了叶顶负荷，是提高压气机失速裕度的主要原因。“耦合型处理机匣”与压气机间的作用具有自适应性，这种自适应性降低了其对压气机工作点效率的负面影响，同时保证了对叶顶堵塞的控制效果。缝与喷嘴的耦合设计具有不降低压气机效率的同时，大幅度提高压气机失速裕度的潜力。

关键词: 轴流压气机;端壁失速;处理机匣;耦合;自适应