Liquid Sloshing Dynamics In Spacecraft Tanks Based On The SPH Method

With the increasingly complex space mission and strict pointing accuracy requirements, liquid sloshing in fuel tanks has become an unavoidable factor in the design of the control system. Except for the mature and expensive experimental method, the linear theory and equivalent model method can be taken to solve the small amplitude linear liquid sloshing. However, the strong nonlinear influence is an outstanding issue in the field of large amplitude sloshing, which leads to traditional grid method without a good applicability. In this paper, liquid sloshing problem based on SPH method which is a sort of meshless method in ordinary gravity is mainly studied.In this paper, the application prospect and basic thought of SPH method is introduced. Following is the numerical method in the process of programming and the realization with C programming language. Based on the traditional method, we solve several problems including the closure cavity shear flow, the dam break movement and the small amplitude linear sloshing, which proves that the SPH method can deal with the incompressible free surface flow effectively.In addition, the numerical processing in the issue of large amplitude sloshing based on SPH is introduced in detail. Because of the large space and disordered pressure field near the boundary when using traditional SPH, we have found out a method to thicken the boundary, control the boundary particle distance and influence domain so that reasonable pressure field can be solved correctly. Besides, the way to solve sloshing force and moment based on particle system dynamics is given which has been successfully used in the rectangular tank.On this basis, we discuss the initial particle distribution method which practical complex situations will confront, including the Cassini tank with or without baffles and the complex shape cabin below the tank. Finally, the anti-sloshing effect of the baffle and the situation that complex sharp angles in the tank are easily affected by the impact of sloshing liquid are shown based on the simulation result.Some design suggestions are also presented.