双离心压气机共用单一进气歧管致进口流场畸变的仿真分析

针对V型发动机的共用单一管路对置离心压气机进口流场畸变特性进行了研究,通过台架试验测试了初始压气机性能,完成了仿真模型的标定。在此基础上分析了压气机进口流场的变化特征,分析结果表明:共用单一管路对压气机特性影响明显,造成了两侧压气机堵塞流量的降低,在大流量工况区域效率明显下降,右侧压气机恶化程度要明显高于左侧。原因在于受安装位置空间限制,喉口处畸变扩展与进口周向畸变叠加效应使得右侧压气机在周向和叶高方向的畸变程度均高于左侧压气机。进口的畸变效应会一直持续至压气机叶轮内部,使压气机性能变差。

Simulation Study on the Distortion of Inlet Flow Field Caused by Twin Centrifugal Compressors Sharing a Single Inlet Manifold

In order to improve the aerodynamic performance of twin centrifugal compressors used in a V type turbocharged engine, the distortion of inlet flow field caused by its common inlet manifold were studied. To this end, the initial performance of the twin compressors was tested on a test bed, and the simulation model was calibrated. Then, the distribution characteristics of inlet flow fields of the twin compressors were analyzed. Results indicate that sharing a single inlet manifold has a significant impact on the aerodynamic performance of the twin compressors, resulting in a reduction of blockage flow and a decline in compressor efficiency from the blockage point to the highest efficiency point. Not only that, the performance of the right compressor is more likely to deteriorate than the left compressor. The mechanism that causes this phenomenon is that due to the limitation of installation space, the flow field distortion of the right compressor is higher than the left compressor under the superimposed effect of airflow at the throat and inlet, regardless of the circumferential and blade height direction. Moreover, the distortion of inlet flow field will continue to extend inside the compressor impeller, making the compressor performance worse.