在标准大气工况下针对压比为4.8的离心压气机展开研究，通过ANSYS CFX计算对比了光滑壁面（SW）、无叶循环机匣处理(Vaneless RCT)和负预旋叶片循环机匣(Vaned RCT)离心压气机的流场及流动特性。研究发现，循环机匣处理（RCT）减小了低叶高区域的入射角，通过循环流与主流的掺混扩宽了叶顶区域的流量承载能力，降低叶顶载荷抑制了激波与叶尖泄漏涡、通道涡的相互作用。相对于SW，RCT提高了5%-7%的流量范围。Vaned RCT增强了对叶尖泄漏涡及通道涡堵塞区的抽吸作用，缓解了强逆压梯度造成的吸力面流道堵塞。在Vaneless的基础上，Vaned RCT增强了4.3%的最大压比，提高了2%的流量范围。然而，循环流的流动分离与掺混产生了额外熵产。

A centrifugal compressor with a pressure ratio of 4.8 was investigated under standard atmospheric conditions. Comparative analyses of flow field characteristics were performed using ANSYS CFX for three configurations: smooth wall (SW), vaneless recirculation casing treatment (Vaneless RCT), and negative pre-swirl vaned recirculation casing treatment (Vaned RCT). The investigations revealed that the recirculation casing treatment (RCT) effectively reduced the incidence angle in the lower span region. The flow capacity in the tip region was broadened through momentum exchange between recirculating flow and mainstream, while tip loading reduction suppressed interactions among shock waves, tip leakage vortex, and passage vortex. Compared with the SW, the RCT configurations demonstrated 5%-7% improvement in operating flow range. The Vaned RCT exhibited enhanced suction effects on the blockage zone induced by tip leakage vortex and passage vortex, effectively mitigating flow passage blockage on the suction surface caused by strong adverse pressure gradients. Compared with the Vaneless RCT, the Vaned RCT achieved 4.3% enhancement in maximum pressure ratio and 2% extension of stable flow range. However, flow separation and mixing losses associated with recirculation flow generated additional entropy production.

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