An Analysis of Fluctuating Flow based on Rotating Stall of a Centrifugal Impeller.

This paper describes the unique rotating pressure patterns which appear around an impeller under the rotating stall condition. The above pressure patterns rotate at higher velocities than the impeller rotation. Discussions are made on the source of these patterns based on the analysis of the experimental data. It becomes obvious that the interference occurs between the impeller channel flow and rotating stall cells, and waves propagating around the impeller are generated. One of the waves propagates at higher velocity than the impeller. In addition to that, it is made clear that various types of rotating stalls occur in the impeller/vaneless diffuser system.