中文摘要：

对单级跨音速离心压缩机具有对称和非对称两种形式的圆形截面蜗壳的内部流动进行数值研究，分析蜗壳内部流动以及蜗壳与扩压器相互作用所导致的流动现象和不同工况条件下蜗壳进口周向流动的不均匀性以及两种蜗壳布置形式下各部件的流动损失。计算结果表明：在设计流量下和大流量下，对称蜗壳的蜗舌附近叶片扩压器通道中出现了回流，发生位置都在叶片扩压器叶片凸面；偏心蜗壳仅在大流量时出现回流现象，蜗舌附近区域内部流动情况略好于对称蜗壳。在非设计流量下，静止部件内部损失均大于设计流量，其中在大流量下尤为明显：扩压器内部损失在静止部件总损失中均占到80％以上，蜗壳内部损失小于20％；小流量下叶片扩压器内部损失所占比例小于大流量工况。

英文摘要：

Numerical simulation is carried on to study the internal flow in symmetric and asymmetric volutes, different flow phenomenon caused by the interaction between volute and diffuser are also investigated as well as the circumferential distortion of the flow and loss mechanism in the volute. The results show that under design flow and large flow conditions, there is a recirculation zone in the suction side of the vaned diffuser blade in tongue region of symmetry volute. As to the asymmetric volute, recirculation only appears under large flow condition, and generally the flow condition in asymmetric volute is improved greatly compared with that of symmetric volute. Under off-design conditions, the loss in static components is large than that under design condition, under large-flow condition, the loss in vaned diffuser accounts for more than 80 percent of the loss in static components, and the loss in volute accounts for less than 20 percent, also, the loss in vaned diffuser under small-flow condition is less than that under large-flow condition.