Strength And Sloshing Analysis Of A Liquefied Gas Tanker

The liquefied gas tanker is widely used. However, because of the danger of filling medium, leaking accident of the tankers will cause great property loss and environmental pollution, even threaten to human lives. Therefore, more and more attentions are paid on the safety operation of the tankers. In this thesis, strength calculation and liquid sloshing analysis of the tankers are performed numerically. The main work and conclusions are as follows:(1)A finite element model of a liquefied gas tanker is established with the software of ANSYS. Stress analysis is carried out for the liquefied gas tanker under four different working cases involving four kinds of inertia forces and the strength is check after the stress classification. As the tanker may be in a vaccum condition in the process of filling medium, the buckling analysis is also performed on the tanker and the critical buckling pressure is calculated.(2) Results of stress analysis show that local membrane stress at the rear head is a controlling factor on the rear head strength. For this reason, the effects of the V-shape support of the tanker on the stresses at the head are investigated in this thesis. Specifically, with the optimal design module of ANSYS, the size and location V-shape support are optimized to decrease the stresses at the rear head. Results show that when the rear end of the V-shape support is far away from the head, the stress will be decreased.(3) The thesis simulated the liquid sloshing through the software FLUENT, and at the same time, changes of impact force and pressure was mainly considered. The results show that the initial pressure is much smaller than the maximum pressure and the impact force is larger than the inertia force. At the same time, the factors which influence the biggest impact force produced by liquid sloshing, such as acceleration, filling rate and media types were investigated. Results show that acceleration and filling rate affect both the magnitude and appearing time of the biggest impact, but the medium only affect the magnitude of the biggest impact.