Özet:

The pressure pulsation is one of the key factors affecting instability operation and vibration of large mixed-flow pump units in pumped-storage power station. The unsteady flow field in a mixed-flow pump with different guide vane thicknesses was numerically simulated based on the standard k-ε turbulence model, the SIMPLE algorithm and the sliding mesh technique. By setting pressure measurement points, the pressure pulsation characteristics in the impeller inlet, outlet and the middle of guide vane were discussed and the influence of the guide vanes’ thickness on pressure pulsation was analyzed. The results show that the type of numerical simulation grid, turbulence model can accurately predict the internal flow characteristics of the mixed-flow pump. The dominant frequency of pressure pulsation was approximate to the impeller blade passing frequency. The thickness of the guide vane have less influence on pressure pulsation in the inlet of impeller, and have more influence on pressure pulsation in the middle of guide vane. Compared with the thinning guide vanes, the pressure pulsation amplitude of the thicken guide vane increase 7.8 %. Therefore, appropriately reducing the thickness of guide vane is beneficial to the stability of the internal flow of guide vane.

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