离心叶轮和扩压器相互作用

采用定常和非定常数值模拟技术,研究了某跨声离心压气机级内的复杂流动,分析了叶轮与径向扩压器之间的非定常相互作用.结果表明,扩压器的势干扰使叶轮出口静压发生周期性地变化,引起叶轮后部负荷、叶尖泄漏和损失等也产生周期性地变化,影响范围达30%流向弦长.叶轮出口流场的周向不均匀性及非定常性使扩压器进口参数发生周期性的变化,导致扩压器负荷、总压恢复系数分布呈现出较强的非定常性,影响范围贯穿整个扩压器通道.

Numerical investigation of impeller-diffuser interaction in a centrifugal compressor

Steady and unsteady simulations were conducted on the investigation of complicated flow in a transonic centrifugal compressor with splitter blade. Results from the steady and unsteady simulations were compared and the interactions between impeller and diffuser were studied in detail. The results indicate that the impeller/diffuser interaction can affect a range of 30% impeller chord from impeller trailing edge on impeller performance, while whole chord length on diffuser performance. The potential effects of the diffuser cause an unsteady pressure disturbance for the impeller exit, leading to the unsteadiness of impeller load, tip leakage flow and losses. While the unsteadiness of impeller exit flow cause period varieties of inlet flow conditions for the diffuser and the inlet flow angle was found to be the most significant parameter in setting diffuser performance, resulting in the significant unsteadiness of blade load and total pressure recovery coefficient.