Abstract:In order to analyse the unsteady flow characteristics in a double-blade pump,the computational domain composed of impeller,volute casing and the stretch of the inlet of impeller, and the RNG k-ε turbulence model were used to simulate the flow fields under the design condition. The static pressure and relative velocity distributions at different time were compared, and the time-domain spectrums, frequency spectrums and instant lift were investigated. The results indicate that the static pressure and relative velocity distributions of the same passage at different time and those of different passages at the same time are different, that are concerning with the relative locations between the passages and the tongue. There have pressure fluctuations in the double-blade pump evidently, and near the tongue area the pressure fluctuations are of the most violent ones. Along with the distance from the tongue increasing the pressure fluctuation strength becomes weaken gradually, and the dominant frequency is equal to the blade passing frequency. The simulation can offer certain theoretical basis to understand the flow rules in the double-blade pump, raise efficiency and decrease hydraulic loss.
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