The Effect Of Blade Thickness On Axial Flow Pump Performance

The impeller is the core component of the Axial Pump Sets,mechanical energy is transferred to water by it in the system, it is the part that make the energy of the water increased, the performance of the Axial Pump Sets is determined by it. The pump in many of the water transfer and drainage-irrigation pump station that are being builded are vane pumps. So the study of the influence in pump performance by impeller structure parameters that has the instructing significance.Numerical modeling and mesh generation could be realized by geometric modeling software ICEM, Turbo-Grid. Based on the RANS equation and RNG k ?εturbulence model,with the numerical model which is created by ICEM and Turbo-Grid, three-dimensional incompressible flow fields numerical analysis could be simulated by commercial 3D software CFX. Interior characteristics and external characteristic of different scheme (different thickness of the blade, different angle of the blade, and different shape of the hub) could be carried out.Through analyzing the calculation result with CFX-Post, we could see: (1) When the impeller blade become thiner ,the lift and shaft power of the axial pump increase at the same discharge. Maximum efficiency point move to the larger discharge point and become larger at the same time; (2) When the impeller blade become thinner, the blade expelling coefficient become smaller, area of passage become larger, the velocity become smaller at the same discharge. According to velocity triangle at the entry, flow angle become smaller, equivalent to incidence angle become larger for airfoil, the lift and shaft power of the axial pump become larger, (3) At the same discharge, when the impeller blade become thinner, the pressure of the pressure surface of the axial pump become larger, which bring on the lift become larger. The pressure of blade suction surface, which cause that the cavitation of the blade improve. (4) When the hub change to cylinder from spherical surface, because the flow sections become larger, however, blade expelling coefficient become smaller, its mechanism and effect is similar to the effects of the thinner of the blades, that is the lift and shaft power of the axial pump increase at the same discharge, maximum efficiency point move to the larger discharge point, and it become larger.