离心压气机是涡轮增压器的核心部件，对于高压比离心压气机来讲，一般采用有叶扩压器。与无叶扩压器相比，在相同直径比时，有叶扩压器具有更大的扩压能力和更高的效率。但是，受扩压器叶片攻角的影响，压气机非设计工况效率比无叶扩压器要低，而且压气机稳定工作范围变窄。本研究针对有叶扩压器离心压气机流动稳定性的提升，通过蜗壳非对称性对有叶扩压器内部流动的影响研究，改变蜗壳喉口处对应扩压器叶片分布形式以及叶片的安装角，设计了一种非对称有叶扩压器结构，并分析了有叶扩压器内部流动特性的变化，最终通过了台架试验验证。验证结果表明：采用非对称有叶扩压器结构能够有效拓宽离心压气机的稳定工作范围，在高压比区域，较对称叶片式扩压器离心压气机流量范围提升10%左右。

Centrifugal compressor is the core component of turbocharger, which usually uses vane diffuser for the high pressure ratio. Compared with vaneless diffuser compressor, the vane diffuser with the same diameter ratio has larger diffused pressure stability and higher efficiency. However, the efficiency of vane diffuser is lower than vaneless diffuser at offdesign points because of the influence of vane attack angle and the stable work flow range becomes narrow. For the stability improvement of centrifugal compressor, an asymmetric distribution vane diffuser was put forward by studying the effects of volute asymmetric structure on diffuser internal flow and changing the vane distribution form and setting angle of diffuser at the throat of volute. The variation of internal flow for vane diffuser was further analyzed and verified by bench test. The results show that the asymmetric vane diffuser can expand the flow range by around 10% at the high pressure zone of compressor.