Numerical 3D Simulation of the NPSH Characteristics of Centrifugal Pumps with Local and Integral Analysis of Void Structures

3D numerical simulations with mass transfer cavitation model are performed in a centrifugal pump (  =26 min -1 ).Simulation results are compared to measurements of  characteristics and optical measurements of void structures.Transient single bubble cavitation is observed in the experiments with hydraulically smooth blades, whereas in the simulations, the cavitation region appears as stationary sheet cavitation for the entire operation range.Local cavitation structures in the impeller are spatially integrated for measurements and simulation results.The resulting cavitation intensity provides additional information on the extent of cavitation zones at  levels well above  % , where the head is yet unaffected by cavitation.The  % curve as well as cavitation intensity are well predicted, although local void structures show a mismatch to measurements.