Numerical simulation and experimental investigations of 50IB-32 centrifugal pump′s cavitation
(1.Research Center of Fluid Machinery Engineering and Technology, Jiangsu University, Zhenjiang, Jiangsu 212013, China; 2.National Research Center of Pumps, Zhenjiang, Jiangsu 212013, China)
Abstract:In order to study the internal flow inherence of the impeller when the pump was in cavitation, based on Rayleigh-Plesset cavitation model and RNG k-ε turbulence model, the whole flow passage of 50IB-32 model pump under the design conditions was numerically calculated. The development of cavitation in the flow of the impeller was compared and analyzed in primary cavitation, critical cavitation, and serious cavitation. Static pressure distribution on pressure side and suction side of blade and vapor volume fraction of the blade under different NPSH were obtained by the numerical calculation. The results show that bubbles first appear in the low pressure area of the suction side of blade and then extend from the inlet to the main flow as inlet pressure decreases; bubble distribution on the blade gradually increases. In critical cavitation, bubbles extend inside the flow; in serious cavitation, the flow was filled with bubbles, which disturbs and damages energy exchange in the flow and cause overall performance curve to degrade. The results of the experiment agree with the simulation, which validates the feasibility of numerical calculation.
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