Unsteady Flow Numerical Analysis of New-Type Deep Well Pump Under Multi-Conditions

The interaction between impeller and guide vane of the deep well pump is one of the most important factors which cause the pressure fluctuation in the channels. However, even nowadays some flow events in the deep well pump are still under study and far from fully understood. So the unsteady flow field of a two-stage deep well pump was simulated with FLUENT code based on sliding mesh and the RNG k-ε turbulence model, to investigate the pressure fluctuation by interactions between the impeller and guide vane. The computing domain extends from the inlet of the first stage deep well pump to the outlet of the second stage guide vane. With the Fast Fourier Transform (FFT) analysis, the pressure fluctuation and frequency fluctuation are analyzed under multi-conditions. In this paper, the pressure fluctuation differences between the first stage and secondary are also compared. The numerical results show that the pressure fluctuates at the blade passage frequency, and the maximum amplitude of blade passage frequency occurs in the region from the rotor to the stator when the impeller blade gets close to the guide vane trailing edge, but it decreases rapidly after fluid entering the guide vane. Compared with the steady simulation, the averaged calculated single-stage head of unsteady simulation is more accord with the reality, which is less than the tested head with a relative deviation of 5%.