中文摘要：

采用三维CFD（计算流体动力学）方法，对两种相反叶尖间隙分布方式的无叶扩压器压气机级进行了详细流场分析，研究了叶尖间隙分布对跨声速离心压气机叶轮及扩压器性能的影响机理．结果表明，非均匀分布弦向间隙分布叶轮有较宽的稳定工作范围；出口轴向间隙小于进口径向间隙的压气机级压比和效率明屈高于出口轴向间隙大于进口径向间隙的压气机级．较小的出口轴向间隙削弱了叶轮通道后半段间隙流动，显著提高了叶轮后部做功能力，获得更高的级压比；并使叶轮后部间隙涡强度及涡在叶轮通道和扩压器通道内耗散损失小，压气机级效率更高．

英文摘要：

Based on three dimensional computational fluid dynamics method, the flow fields of two opposite impeller blade tip clearance distribution compressor stages with vaneless diffuser were analyzed. The law and action mechanism of tip clearance distribution effect on the high charging ratio transonic centrifugal compressor impeller and vaneless diffuser performance were researched. This proves that non-uniform chord direction blade tip clearance distribution impellers have wider operating range. The pressure ratio and efficiency of compressor stage whose outlet axial clearance height is smaller than inlet radial clearance height are higher than that of compressor stage whose outlet axial clearance height is larger than inlet radial clearance height. The smaller outlet axial clearance height weakens the clearance flow in aft half of impeller passage, improves the impeller aft passage power input and obtains higher impeller pressure ratio and compressor stage pressure ratio. The smaller outlet axial clearance height gets higher efficiency since it reduces impeller aft blade tip clearance leakage vortices intensity and makes the vortices breakdown and dissipation loss less in impeller passage and vaneless diffuser passage.