ABSTRACT

Both potential and wake interactions are usually the primary mechanisms related to the unsteadiness in turbomachines. However, it is usually difficult to distinguish their effects on flow evolution. This paper develops a direct and visual method to investigate the effects of wake and potential interactions on features of the flow velocity in a two-stage centrifugal refrigeration compressor. The centrifugal compressor consists of six cascades of blades/vanes, i.e. inlet guide vanes in the first stage, impeller blades and vaned diffusers in both stages and return channel in the second stage. The detailed features of flow velocity, such as time-averaged flow velocity, instantaneous flow velocity and power density spectrum of the flow velocity, downstream each cascade of blades/vanes are studied in detail to investigate the potential and wake interactions on the flow evolution in the centrifugal compressor.

摘要

潜在相互作用和尾流相互作用通常都是与涡轮机不稳定有关的主要机制。但是，通常很难区分它们对流动演化的影响。本文开发了一种直观的直观方法，以研究尾流和潜在相互作用对两级离心式制冷压缩机中流速特征的影响。离心压缩机由六级叶片/叶片组成，即第一级的进口导向叶片，两级的叶轮叶片和叶片式扩散器以及第二级的回流通道。流速的详细特征，例如时间平均流速，瞬时流速和流速的功率密度谱，