Sloshing analysis of the independent tank type C due to the LNG ship motions using computational fluid dynamic

Abstract

This paper discuss the sloshing effect of tank containing LNG (Liquid Natural Gas) due to the LNG ship’s motion during operation at sea. Sloshing was numerically simulated in two dimensional transverse tank by using Computational Fluid Dynamic method. The Iso tank in the form of Bilobe which was the type of Independent Self Supporting Tank C was considered to be analyzed based on the motions of LNG ship such as Sway, Heave, and Roll in irregular wave. Three variations of the LNG filling level inside the tank i.e. an empty condition (10% of tank height (h)), a half condition (50% h), and a full condition (90% h) were oscillated for certain period of times in order to obtain the maximum pressure occurred on the inner wall of LNG tank. The simulation results shown the magnitude of the static maximum pressure on Tank wall in full load condition was about 16349.56 Pa and it larger than a half load condition of 6891.16 Pa as well as an empty load condition of 618.37 Pa. The pressure increased due to sloshing about 1.47 % in full condition, 2.35% in a half load condition, and 12.96 % in an empty load condition. The result of the probability occurrence calculation shown that the maximum pressure on wall area of the LNG tank for all LNG filling level conditions within 6%.