Analysis And Optimization Of Cavitation Performance Of An Aviation Fuel Pump

Fuel pump is a main component in the fuel supply system, which has a direct influence on the dynamic performance and mobility of the plane. With the development of aviation technology, the fuel pump develops towards the high speed and high power performance, which will induce cavitaion, followed by many problems such as the rotating stall, noise and efficiency decreases. Hence cavitation becomes one of the major issues for the development of the pump characteristics. So it has a great application value to investigate the cavitation performance of fuel pump. In this paper, numerical simulation and surrogate-based optimization were applied to a RP-3 fuel pump. The main content and conclusions are as follows:The physical properties of RP-3 kerosene were studied with an surrogate fuel, which consists of 45% dodecane, 25% decane, 5% octane, 5% methylcyclohexane and 20% toluene(mole ratio).A revised k-ε turbulence model based on the local swirling correction was applied, which avoids the over-prediction of turbulent eddy-viscosity and increases the accuracy of the numerical simulations.Based on the numerical simulation results, the cavitation performance was studied, and the effects of temperature and rotation speed on the cavitation performance of fuel pump were analyzed. The results showed that, compared to the performance of general centrifugal pump, there was no hump zone on the characteristic curve, and a larger high-efficiency zone can be observed. With the decrease of NPSHa, the cavitation characteristic curve kept steady at first and then increased, followed by a sharp decrease. The temperature had small effect on the cavitation performance of fuel pump and the value of NPSHr almost the same with different flow temperature. While the rotation speed had great influence on the cavitation performance, and the value of NPSHr changed a lot with different rotation speed. The higher the rotation speed, the more significant the cavitation developed.In order to improve the cavitation performance of fuel pump, the global sensitivity analysis that based on the surrogate method was applied in this study, and also, the structure parameters of fuel pump had been optimized. The results showed that the cavitation performance was mainly influenced by outlet angle of inducer and inlet angle of impeller, and the latter played a more important role. With the increase of inlet angle of impeller, the cavitation performance firstly decreases and then increases. Based on the Pareto optimal solutions, the optimized outlet angle of inducer and inlet angle of impeller increased by 4.4° and 3.2° respectively, with the cavitation performance increased by 18%.