EXPERIMENTAL AND THEORETICAL FLOW FIELD ANALYSIS OF MIXED FLOW PUMPS

摘要

Mixed flow centrifugal pumps often exhibit a pronounced flattening of the head-flow curve at partial flow capacities/When these pumps are applied in systems having a resistance curve that is not very steep, system instability can occur. Thus, there is a strong interest to understand the root causes of the curve slope. In the present paper, the experimental and theoretical work undertaken on a model 20 inch impeller of a mixed flow, single stage pump is described. The flow separations occurring on the suction and discharge sides are clearly seen. The numerical computation is shown to be very powerful and capable of accurate predictions over a reasonable flow range. It is hoped that when the details of the diffuser flow field are also calculated, good predictions of the overall head-flow curve will become possible. This will then lead to the development of design strategies to minimize the potential for instability.