Overview for Research on Rotating Stall of Pump

The discoveries about the rotating stall of the pumps were summarized according to previous researches.It contains the methods,results and suppression of rotating stall using CFD or PIV and combing with experimental methods.Most of the researches focus on the flow structures and pressure fluctuation and propagation when the rotating stall occurs.There are alternate reverse flow and jet flow because of the alternate high pressure region and low pressure region in the diffuser passage.It also appears high speed leakage in the clearance between the impeller and diffuser.Under stall condition it will be found that pressure fluctuation and propagation and part of the dramatic change pressure is about 0.7 percent of the impeller rotating speed as the same direction of the impeller rotating.In addition,most of the researches have found that the rotating stall occurs when there is a change in the slop of the performance curve.Finally,it suggests two possible ways to suppress the rotating stall in the pumps.