本文主要研究单级离心压气机的改型设计，并采用数值方法对楔形扩压器前掠展开了详细研究。在保持原有压气机叶轮外径不增加、流量和设计转速不变的条件下，将压比由4.0提高到4.5。在设计离心叶轮时，首先需要确定叶轮后弯角，为了真实评估叶轮后弯角对离心压气机效率和稳定性的影响，详细设计了后弯角为20°，25°，30°和35°的三维叶轮以及相匹配的楔形扩压器，最终选择35°后弯角叶轮。其次，后弯角为35°叶轮的设计点压比相对于设计目标偏低，将hub处弯角减小到30°达到增加设计点压比。最后，考虑到楔形扩压器各截面载荷的不同，研究了楔形扩压器前掠对性能影响。%This paper mainly described the aerodynamic redesign of a single stage compressor with the pressure ratio improved from 4.0 to 4.5, while the impeller tip diameter, the speed and mass flow are unchanged. At the same time, it investigated the forward-swept wedge diffuser numerically. When design centrifugal impeller, the backward angle of impeller needed to be determined. For truly evaluating the influence of impeller backward angle on efficiency and stability of centrifugal compressor, the 20° , 25° , 30° and 35° backward angle impellers and the corresponding wedged diffusers were designed in detail. Finally, the 35° backward angle impeller was selected for the consideration of stall margin and efficiency. But the pressure ratio couldn’t reach the design target. The problem was solved through the reduction of the backward angle to 30° at the hub. Finally, the influence of forward-swept wedge diffuser on performance was researched, taking the consideration of the spanwise load variation of the wedge diffuser.
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