Dynamic Analysis For Liquid-filled Multi-body System Based On SPH Method

In engineering fields,there are vast kinds of liquid-filled multibody systems.In case that the amplitude of liquid sloshing increases,the influence of liquid sloshing on the rigid body motion can not be ignored.The methods of analyzing the liquid-filled problems include the theoretical analysis approach,experimental analysis approach,traditional numerical method based on grid and the mesh free Smoothed Particle Hydrodynamics method(SPH).The theoretical analysis approach can be taken to solve the small amplitude liquid sloshing in container with regular geometry.Such method has high computational efficiency but limited applicability.The experimental analysis method is more effective in dealing with nonlinear sloshing problem,but the experimental cost is high and there are many uncertain factors that may influence the experimental results.The traditional numerical methods based on grid are relatively mature,but the distortion and reconstruction of the grid may lead to a decrease in the computational efficiency when large deformation occurs.In this paper,the problems of liquid sloshing and liquid-structure interaction are studied based on SPH method.Firstly,the engineering background and research significance of coupling dynamics of liquid-filled multibody system are introduced.Following is the research methods and advances on liquid sloshing and liquid-structure interaction.Besides,the development,the basic process and the study of liquid sloshing based on SPH method are introduced.In addition,the equations of field function and its gradient of SPH method are presented.The fluid dynamics equations are derived by SPH method.Various concepts of SPH method are described,including smoothed kernel function,particle support domain and auxiliary equation.By taking into account the inertial force,the fluid dynamics equations in non-inertial system are derived.Next,several problems including the shock tube,the cavity shear flow and the dam break are solved.The feasibility and the effectiveness of SPH method in dealing with the fluid dynamics are verified.Compared with previous studies,the problems of liquid sloshing in a translational or rotating tank are simulated.The validity and accuracy of SPH method in studying large amplitude sloshing are illustrated.On this basis,the sloshing force and moment between liquid and rigid body are derived,considering the interaction of liquid sloshing and tank motion.The dynamic equations of multibody system are derived by introducing the constraint equations.By solving the coupled fluid dynamics equations and the dynamic equations of multibody system,several problems are simulated,including the tank motion under periodic exciting force or moment and the car movement under brake torque.The feasibility and the effectiveness of SPH method in dealing with liquid-structure interaction problems are verified.