Abstract: In order to study mixed flow pump performance in pump hydraulic pressure system, the relevance between pump performance parameters and physical quantities during the system working process is analyzed. The formulas of mixed flow pump design flow rate, head and other parameters are derived successfully based on submerge equipment kinematic equations, and mixed flow pump design parameters are calculated to meet weapon launching requirements. Open discharge structure of pump exit is optimized based on the CFD method, and double arcs in the axial plane are designed to reduce the hydraulic loss. Numerical results show that area of passage in discharge structure with double arcs changes uniformly without vortex region, so the efficiency of pump device is improved because of the good pressure conversion capability. The slope of flow rate-head curve is increased by optimization of the blade wrap angle and blade outlet angle. The head of optimal case is higher in the full flow rate range, which could meet the equipment acceleration requirements at different operating conditions. Blade outlet flow pattern is optimized based on the non-linear circulation distribution, and the hydraulic efficiency is increased. The maximum efficiency of the optimal pump reaches 83.24%, which meets the design requirements.

Key words: mixed-flow pump;impeller;open discharge structure;numerical simulation;optimization design