中文摘要：

利用三维数值模拟的方法对一跨音速离心压缩机进行了气动设计优化分析，研究了变叶片数和分流叶片结构对叶轮以及级性能的影响。结果表明：在固定叶片数下，不同长度的分流叶片在小流量下性能差距不大，但是在大流量工况下，带有长分流叶片的叶轮性能迅速下降；不应该简单地选择长叶片的截短作为分流叶片，分流叶片的型线优化同样有必要，也应该引起足够的重视；对本文算例，通过对不同叶片数、不同分流叶片形式的研究，最终确定18～20为最佳叶片范围，其整体性能优于原设计。

英文摘要：

The method of numerical simulation is used to optimize the aerodynamic design of a transonic centrifugal compressor, effects of the splitter blade number and lengths of splitter blades on the centrifugal compressor performance have been investigated. The results showed that at a fixed blade number condition, length of splitter blades has no much influence on the performance of centrifugal compressor under low flow rate condition, but under large flow rate condition, the performance decreases with the increasing length of splitter blades. Great attention should be paid to the Profile line optimization of splitter blade. Based on the given centrifugal compressor model, numerical simulation were carried on to obtain the best blade number, analysis showed 18 to 20 is the best blade number range and performance is better than former compressor.