Abstract: Fluid loss caused by leaks through the impeller tip clearance was investigated for a centrifugal compressor.Operating conditions and clearance were varied independently during the experiment It was found that the average compressor performance would be reduced by about 10% when the relative clearance was increased from 2 8% to 6 9%.The leak velocity in clearance was measured by hot wire.Moreover,the distribution of velocity at impeller exit was taken and the results show that the reverse flow occurs near hub side in small flow rate.

Key words: Unshrouded centrifugal impeller +;Clearance measurement;Flow rate;Experiment

摘要： 通过实验研究，得出了半开式离心叶轮间隙对效率及压力的影响和不同间隙下叶轮出口径向速度的变化规律。在间隙一定，当流量从大向小变化时，主流区从轮盘侧向轮盖侧移动，有时在轮盘侧观测到明显的倒流现象。用动态热线风速仪对叶轮叶道出口的速度分布进行了集平均测量，得出了不同流量下的速度分布。

关键词: 半开式离心叶轮;间隙测量;流量;实验