Electric Pressure Liquid Circulation System Research

The centrifugal pumps are used to supply fuel to the engine of the fuel supplysystem of plane. But they are too heavy that increase the quality of the plane.And their volume is too big that reduce the space of fuel tank. Along with theincrease of the flight time, the failure rate rise greatly because of the agingof the complex power lines and control segment. Therefore, it is necessary todevelop a new type of equipment instead of centrifugal pumps.Ejector pump which is the core part of electroless and negative-pressureliquid circulation system，have some characteristics , such as small, light,simple structure, no electricity, no moving parts, reliable, easy maintenanceand low cost. It is very suitable for fuel-supplying instead of centrifugal pumps.However, the ejector pump structure result in the low work efficiency and thepoor reliability of the fuel supply. Therefore, it is very important to optimizethe structure parameters of ejector pump. Get higher ejector coefficient is theaim of research.Based on their basic structure and the theory, the structure model ofannular-ejector pump is built, the jet mechanism of the annular ejector pumpis studied, the Bernoulli equation of energy conservation of the annular ejectorpump is established. Moreover, the calculation equation on cavitation is derived.According to the existing research results, an orthogonal test , which have fourfactors ,is designed. Each factor has four levels. The four structure factorsare the clearance of ring nozzle, and injection angle, and the diameter and lengthof bronchia pipes. Using CFD theory，two-dimensional mathematical model of ejector pump,which is established, is simulated in Fluent software. Ejectorcoefficient is obtained in the different level of combinations.Throughcalculation and analysis the simulation data, it is concluded that four factorshave different influence on ejector coefficient of the annular ejector pump.And using some kinds of optimization design methods find the best value on thefour factors, such as single-element orthogonal polynomial regression designmethod and so on. By comparing the velocity, pressure and turbulent kineticenergy distributions of optimization before and after, it is concluded that theinternal flow field of annular ejector pump is more stable and the effect ofnegative pressure is more apparent after optimizing. In the end, the fuel supplysystem of MA60 plane was designed by the optimized electroless andnegative-pressure liquid circulation system to realize no electricity supplyin the engine fuel system.