Measurements of the Flow in Backshroud/CasingClearance of Precessing Centrifugal Impeller

[摘要] Detailed flow measurements have been made to clarify the unsteady flow in the backshroud/casing clearance of a precessing centrifugal impeller. The unsteady pressure was integratedto obtain the fluid force moment on the precessing impeller shroud for various precessingfrequencies. It was shown that the fluid force moment can become rotordynamicallydestabilizing for small forward precessing motion as originally found by Ohashi et al. Theeffects of leakage flow in the backshroud/casing clearance and a gap between impeller sideplate and casing at the impeller outlet are clearly shown, and the discussions are also madebased on the unsteady velocity and pressure measurements.

[学科分类] 力学，机械学