Study On Liquid Sloshing In Flexible Tank And Its Interaction With Ship Motions

With the development of the trade and increasing need of resource, as well as thedevelopment of the ship building industry, sloshing problem is becoming a focus point toresearchers and ship designers. It is more obvious in liquid cargo ship, such as LNG andLPG. Suffer from the wave load, a series of ship motion may take place, such as heaving androlling, and the liquid tank will also move which leads to liquid sloshing. Due to the liquidsloshing, the tank will deform and ship motion will also be influenced that both flow field inthe tank and flow field out of the ship will change. It is necessary for ship researchers anddesigners to simulate this series of problem and exactly forecast the ship motion and thestructure reaction. Although the liquid sloshing, ship motion and FSI problem have beenpreliminarily studied in20thcentury, but today, with the improvement of the theory andcomputer skill, it is possible to study the three problems as a whole. Because of the complexFSI problem and the interconnection of inner flow field and outer flow field, as well as thelarge amount of calculation, only preliminary try and exploration are carried out. The jobincludes:1) Read large number of paper which concern the elastic sloshing, interconnection of rigidsloshing and ship motion and interaction of elastic baffle and sloshing. Comprehensivesummarize on research of sloshing was carried out;2) Established a mathematical model which includes the basic equations of fluid motion andstructure motion and boundary conditions. The numerical method of FSI problem was alsoproposed.3) Based on FSI theory, rigid sloshing and elastic sloshing were respectively simulated andthe results were compared with that of literatures and theory. The correctness of that solvingFSI problem with ANSYS was verified.4) ANSYS was used to simulate the motion of rigid body in the wave. The results werecompared with that of literatures and theory, which verified the correctness and feasibility ofusing ANSYS to simulate the motion of rigid body in out fluid flow.5) Interaction of elastic sloshing with ship motion was simulated by ANSYS. The influenceof elasticity of tank on the heaving and rolling of ship and pressure of tank were analysed.The pressure of tank was transformed into the frequency domain. The stress and strain ofliquid tank in elastic sloshing were also preliminarily analysed.