SPH Simulation And Parametric Analysis On Sloshing Tank

Liquid tanks are indispensable segments of ships and offshore structures. The rolling movement of the hull or structure motivated by wave or other environmental loads can be conducted to the liquid inside the tanks. In partially filled conditions, liquid will flow inside the tank and wave emerges, smoothly or violently, well known as sloshing. It can not only cause damage on the tanks' wall structures, but also lead to instability or even capsizing of the vessels. Thus, sloshing is a major safety concern in transport industry. We use a meshfree numerical method, Smoothed Particle Hydrodynamics (SPH for short), to simulate the sloshing problems in 2D rectangular tanks. The main concern in this dissertation is the phase lag between the water movement and the tank moment. Four nondimensional parameters, which can govern the phase lag, are proposed through dimensional analysis. Then several groups of simulations are carried out to discuss the effect of each parameter.SPH is a newly developed meshfree numerical method, in fully Lagrangian form. The problem domain is discretized into particles, which carry the material properties and do not connect with each other by girds. So SPH is superior to other mesh-dependent methods in solving the strong nonlinear problems, such as large deformation and so on. The principles of SPH and its applications to hydrodynamics are introduced. The dam collapse problem is used as benchmark to verify the reliability in hydrodynamics of SPH by a comparison between simulation and experiment.Until last few years, SPH method has been applied to study sloshing. Its advantage is that the free surface condition is satisfied automatically and does not need any complicated special treatment, thus it can represent sloshing phenomenon very well, which is confirmed by a comparison between simulation and experiment under a certain condition.The innovation of this dissertation is the proposal of four nondimensional parameters, as frequency ratio, depth breadth ratio, rolling amplitude and rolling Reynolds number. These parameters can govern the phase lag between the water movement and tank movement. Several groups of simulations are carried out to discuss the effect of each parameter. The results show that as long as the similarity law based on the four nondimensional parameters is satisfied, the scale effect of sloshing can be ignored. Besides, within the interesting range, the phase lag has some positive correlation with frequency ratio and depth breadth ratio, while the rolling amplitude's effect is insignificant.