Iteration design of direct and inverse problems and flow analysis of mixed-flow pump impellers

A design method was developed using iteration calculation of direct and inverse problems to design mixed-flow pump impellers. The method covers the shortage of the traditional design method, the meridional flow calculation of which only satisfies the continuity equation of fluid when designing the blade. The method also considers the effect of the blade shape on the calculation of the meridional flow field. The direct problem when designing the impeller was settled using iterative calculation for two kinds of stream surfaces to solve the continuity and motion equations of fluid. The inverse problem of the mixed-flow pump impeller was settled using point-by-point integration method to draw the blade shape, thickening the blade and smoothing the leading edge of the blade by conformal mapping. The impeller was not ultimately determined until the iterative calculation of direct and inverse problems were converged. The three-dimensional flow field of the mixed-flow pump impeller was simulated with the velocity and the pressure distributions inside the impeller obtained by solving Navier-Stokes equation and RNG k-e turbulent model equation using SIMPLEC algorithm. Simulation results show that the blades designed using this method lead to stronger control of flow, steadier internal flow of the impeller, more uniform pressure distribution and better hydraulic performance.