Abstract:
The cost of numerical simulation can be reduced by properly simplifying the physical model of the pumps, but unreasonable simplification may lead to large simulation error. In order to study the effects of pump chamber and wear ring on the simulation error of a miniature super-low specific speed centrifugal pump, numerical simulation had been carried out by Fluent based on the whole flow field model and non-whole flow field model. To verify the accuracy of numerical simulation, the external characteristic experiment had also been carried out on a miniature pump special test rig. The reasons that lead to the simulation error were analyzed by comparing the simulation results with the experiment results. It is observed that the simulation error of the whole flow field model is 11.6% lower than that of the non-whole flow field model. The whole flow field model can simulate the hump phenomenon of head curve, the jet-wake phenomenon at impeller outlet and the asymmetric flow field distribution in volute. The non-whole flow field model cannot simulate the disk friction loss in pump chamber, which leads to a large error in power and efficiency simulation. The non-whole flow field model cannot simulate the leakage from wear ring, which makes the simulation value of the fluxes through impeller lower than the actual value, resulting in a large error in internal flow distribution simulation.