Numerical study of wake and potential interactions in a two-stage centrifugal refrigeration compressor

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.

Keywords

• centrifugal compressor
• unsteady flow
• wake interaction
• potential interaction