离心压气机无叶扩压器内部流动的实验测量和数值分析

对离心压气机无叶扩压器内部的流动进行地测量，实验在6种不同转速下进行，获得了径向速度、周向速度和静压恢复系数的分布规律，用SIMPLEC算法结合k-ε湍流模型对该无叶扩压器内部流动进行了数值模拟，计算结果与实验值基本吻合，结果表明：气流速度沿扩奢器宽度方向的分布是盘侧高一增侧，速度分布逐渐达到均匀，当提高转速时，气流速度沿扩压器宽度方向的变化较小，压力恢复系数在无叶扩压器前段增长较快，在后段增长缓和。

Experimental Measurementsand Numerical Simulations of the Internal Flow Field in Vaneless Diffuser of a CentrifugalCompressor

The internal flow field in vaneless diffuser of a centrifugalcompressor was measured at six rotational speeds in order to obtain the distribution patterns of radial velocity,circumferential velocity and static pressure recovery coefficient. SIMPLEC algorithm coupling with k-ε turbulence model was adopted to simulate the flow field. The computed results are in good agreement with the experimental data. In the diffuser′s width direction,there are a higher velocity near the hub and a lower velocity near the shroud. However,moving away from the impeller,the velocity distributions gradually reach uniform. While the rotational speed increases,the velocity presents less variations in the hub-to-shroud direction. In front of the diffuser the pressure recovery coefficient rapidly rises with increasing R values,while in rear it rises slightly. These conclusions are useful for engineering design and application.