Abstract: The leading edge structure of diffuser has an important effect on its performance and flow field. To extend the stable operating range of centrifugal compressors, a series of numerical simulations was performed in a highly loaded centrifugal compressor to investigate the flow mechanisms of slotted diffuser, and discuss its influences on the stage performance and stall margin. The results indicate that the stall margin of centrifugal compressor was enhanced by 13.5% without performance deterioration. It is because that the leakage flow passing through the slotted portion suppresses the flow separations in the diffuser passages effectively. As the result of this, it enhances the stall margin without stage performance deterioration.

摘要： 扩压器前缘几何结构直接决定着扩压器的性能和内部流场特性，为进一步拓宽离心压气机的稳定工作范围，以高负荷离心压气机为研究对象，利用经过校核的数值模拟方法开展扩压器叶片前缘开槽流动机理研究，详细讨论了扩压器开槽对压气机性能及内部流动影响的机理。研究结果表明，扩压器叶片前缘开槽能够在保证离心压气机性能基本不变的前提下，使其失速裕度提高13.5%，与原型扩压器相比，扩压器叶片前缘开槽所诱导的间隙泄漏流能有效抑制扩压器通道内的流动分离，从而提高了离心压气机的稳定裕度。

关键词: 离心压气机;扩压器开槽;数值模拟;失速裕度;流动分离