It is expected that a narrower stable operating range and higher aerodynamic efficiency can be simultaneously obtained in a centrifugal compressor with a vane diffuser. How to expand the stable operating range has become an important and critical point in the study of centrifugal compressors. In the paper, the combination treatment of a hub side slotting and low solidity of diffuser vanes of a centrifugal compressor was implemented. Through steady-state and transient computational fluid dynamics (CFD) work, the influence of this newly proposed diffuser treatment method on the stable operating range and efficiency of the compressor was investigated. The results show that the low-solidity vane diffuser with hub side slotting treatment can improve the flow stability of the diffuser channel near the surge state and expand the choke boundary of the compressor. It may also recover some of the efficiency loss due to the switching to the low diffuser solidity. The mechanisms of these effects were analyzed, and the results show that in the case of reduced mass flow, the hub slot sucks in the stagnant fluid in the shroud region from the pressure side of the diffuser and transports it back to the suction side of the diffuser, forcing the fluid there to move upward toward the shroud, thereby improving the flow of the diffuser and avoiding the stall of the diffuser shroud.

期望在带有叶片扩压器的离心压缩机中可以同时获得更窄的稳定工作范围和更高的空气动力效率。如何扩大稳定运行范围已成为离心压缩机研究的一个重要和关键点。论文对离心式压缩机扩压器叶片轮毂侧开槽与低密实度进行了结合处理。通过稳态和瞬态计算流体动力学 (CFD) 工作，研究了这种新提出的扩散器处理方法对压缩机稳定运行范围和效率的影响。结果表明，采用轮毂侧开槽处理的低密实度叶片扩压器可以提高扩压器通道在喘振状态附近的流动稳定性，扩大压气机的阻流边界。由于切换到低扩散器坚固性，它还可以恢复一些效率损失。对这些影响的机理进行了分析，结果表明，在质量流量减少的情况下，轮毂槽从扩压器的压力侧吸入护罩区域内的停滞流体，并将其输送回扩压器的吸入侧。扩散器，迫使那里的流体向上朝向护罩移动，从而改善扩散器的流动并避免扩散器护罩的失速。