离心压气机混合回流机匣处理的数值研究

Numerical Investigation on Mixed Recirculation Casing Treatment in Centrifugal Compressor

机匣处理是一种较早被研究和成功运用的压气机被动扩稳技术。传统机匣处理研究一般针对叶轮部件,本文针对叶轮和扩压器提出了混合回流式机匣处理,采用数值模拟的方法,研究了混合回流式机匣处理的扩稳效果和扩稳机理。研究结果表明:较为理想的混合回流式机匣处理方案可以提高9.4%的失速裕度,设计点效率下降1.7%。混合回流式机匣处理对叶轮主叶片前缘、扩压器叶片前缘以及扩压器叶片尾缘的气流改善是实现扩稳的主要原因。

The casing treatment is one of passive control techniques to extend the operating stability of centrifugal compressor and has been successfully adopted,commonly in the impeller.In the paper a mixed recirculation casing treatment simultaneously used in the impeller and diffuser is presented,and its effect on the extension of operating range as well as the mechanism is investigated numerically.The results shows that,an appropriate mixed recirculation strategy can increase the stall margin of compressor by 9.39%though at the costs of the efficiency sacrifice of 1.7%under the design condition.The expansion of the compressor＇s operating range is mainly attributed to the flow improvements near the impeller＇s leading edge and the diffuser＇s leading and trailing edges.