叶片弯曲程度对离心压气机性能的影响

采用离心压气机计算机辅助集成设计系统设计直叶片、正弯叶片和反弯叶片3种离心压气机叶轮.对具有不同弯曲程度的叶轮内部流场进行三维粘性计算,给出了不同弯曲程度的计算结果,比较了进口中间叶高处具有1.5 mm正弯和反弯叶形叶片压力面和吸力面上的熵分布.计算结果表明,进口正弯叶轮绝热效率略高于进口反弯叶轮的绝热效率;出口正弯和出口反弯叶轮绝热效率基本相同;叶形弯曲对小型离心压气机叶轮效率影响很小.

Centrifugal Compressor Impeller Performance-Comparison of Differently Bowed Blades

Three kinds of centrifugal compressor impellers having straight-line element, positive and negative bowed blades were designed applying computer-aided integrated design system. Flow fields of serial impellers with different bowed blades were calculated by solving three-dimensional Navier-Stokes equations. The results of calculation are given. Entropy distribution on the blade pressure and suction surface having 1.5 mm curving degree at the middle span about positive and negative bowed blades were compared. Calculation results illustrated that the impeller adiabatic efficiencies of inlet positive bowed blades are higher than those of inlet negative bowed blades. The impeller adiabatic efficiencies of outlet positive bowed blades are nearly the same as those of outlet negative bowed blades. Different degrees of curvature in small centrifugal compressors have little effect on the impeller adiabatic efficiency.