Numerical Simulation Of Liquid Sloshing In Transportable Pressure Vessel And Research On The Baffles

Based on establishment of the standard of "liquefied gas tanker" in CSCBPV (China Standardization Committee on Boilers and Pressure Vessels), the research of transportable pressure vessel is carried out and the liquid sloshing in the transportable pressure vessel is simulated by numerical method in this thesis. The numerical method of liquid sloshing with three-dimensional free surface is discussed. The force which the sloshing liquid acts on the rigid wall of the vessel is measured, and the baffles in vessel which prevent liquid sloshing are studied in this thesis. The main research results are as follows:(1) Investigating several factories which produce cargo tanks. The engineers of these factories consider that the provisions of the baffles in cargo tanks aren't reasonable; the volume between two close baffles is small, then the number of baffles is too large; the baffles always fall off. The engineers even disbelieve the baffles capacity of preventing liquid sloshing. By this investigation, the shapes of the baffles and the forms of connection are obtained.(2) Establishing model and method of sloshing simulation. The liquid in the vessel is assumed viscous and incompressible, and the vessel and baffles are assumed rigid. The numerical simulation of three-dimensional liquid sloshing in vertical and horizontal cylindrical tanks is carried out by the software of FLUENT. The sloshing natural frequency is compared and validated with analytic solution, experimental results and numerical results. The liquid sloshing is also simulated when vessel is horizontally decelerated. Then, the mechanical model, the simulation method of the fluid and the turbulence model are selected in reason.(3) Simulation of liquid longitudinal sloshing. The cargo tank is a typical transportable pressure vessel, and liquid sloshing has a serious effect on its safety while driving. The liquid longitudinal sloshing in the cargo tank is simulated successfully at different speed, from steady movement, deceleration, until stillness. The simulation of sloshing in vessel with transverse rigid baffles is carried out, and the force on the baffles and heads is measured and recorded. It contributes to the improvement of baffle form and preventing baffles from falling off.(4) Simulation of liquid horizontal sloshing. The simulation of liquid sloshing is carried out when the tank is turning. The sloshing force on shell arouses overturning moment, and the possibility of tanker overturning increases. The centrifugal acceleration and character of liquid are assumed to be constant, and the overturning moment is related to ratio of filling coefficient.