Centrifugal compressors are widely used in various industries, including aircraft propulsion, automotive transportation, and process applications. Compared to axial machines, centrifugal compressors are more compact and achieve higher pressure rise per stage. A centrifugal compressor stage consists of an impeller and a vaned or vaneless diffuser. While diffuser vanes offer aerodynamic benefits, the relative motion between the rotating impeller blades and the stationary diffuser vanes leads to impeller-diffuser interaction which can potentially cause vibration.
This study aims to understand the aerodynamic mechanism responsible for impeller-diffuser interaction. Numerical study is first carried out and validated against experimental data; then numerical results are analyzed to identify aerodynamic mechanisms which lead to unsteady aerodynamic loads on impeller blades and diffuser vanes.