Waterjet Axial Flow Pump Hydraulic Design And Performance Simulation

Pump stage (including a row of rotor and a row of stator) is the core component of waterjet axial flow pump, and its performance plays a key role in the overall performance of the pump. The reasonable blade angle of rotor, the tip clearance of rotor and the axial gap between rotor and stator, not only improve the hydraulic performance of waterjet axial flow pump, but also optimize the internal flow field of the pump, and improve the anti-cavitation performance of the pump.This thesis intends to design a model of waterjet axial flow pump stage by combining design software with the traditional design theory. The initial assessment of waterjet axial flow pump model is given, what provides a reference for the design of waterjet axial flow pump.Secondly, the geometric models of pump stage with different the blade angles, tip clearances and axial gaps are numerically simulated by the numerical simulation software. The conclusions of performance analysis are as follows:By changing the blade angle it can be found:the head of pump stage can be enhanced when the blade inlet angle increases 2 degrees and outlet angle increases 6 degrees, meanwhile, the efficiency of pump stage increases and flow field is better at large flow condition, but it decreases quickly at small flow condition. It is not conducive to improve the performance. Therefore, the blade inlet angle and outlet angle should be adjusted according to the performance and flow field requirementsBy changing the tip clearance it can be found:with the increase of the tip clearance, the corner separation is weakened, but the tip leakage loss increases so that the hydraulic performance of pump stage decreases, due to the corner separation of blades are more serious when the relative tip clearance is 0.1%, so the optimal relative tip clearance of pump stage is 0.3%.By changing the axial gap it can be found:the axial gap have little impact on the efficiency and head in the large flow condition, but the efficiency and head can be affected complicatly by axial gap in the small flow condition. When the axial gap is between 10-15 mm, hydraulic performance and flow field of pump stage are better, load distribution of stator is relatively uniform, so the best axial gap is between 10-15 mm.