LS-DYNA3D의 유체-구조 연성 해석기법을 이용한 LNG선 탱크의 슬로싱 응답해석

Abstract

Recently, as the demand of LNG(Liquefied Natural Gas) is rapidly increased, the construction of LNG carrier is active and the sloshing problem is also greatly on the rise causing the structural damage in containment system inside cargo tank. Sloshing is a typical field of Fluid-Structure Interaction(FSI) problem, and its numerical analysis approach becomes possible and is actively in progress with an advent and ongoing advances in numerical simulation capabilities and its sophisticated tools.

In this study, numerical analyses for the sloshing of tank model and wet drop test of box model, typical FSI problems, were carried out using ALE Multi-Material Eulerian(AMME) technique of hydrocode LS-DYNA3D. LS-DYNA3D code and analysis technique were also validated through the comparison of simulation results with experimental ones. Through this study, the opportunity could be obtained to establish a more new and effective analysis of FSI problems.

The more accurate solution could be obtained and much less number of finite elements could make an analysis by the application of Grouping algorithm together with AMME technique. It was found that the selection of pressure measuring locations would be very important to get the more close responses to the experimental ones,and that the more exact fluid response behavior, such as breaking wave etc., could be realized.

Through the examination of the correlation between Lagrangian and Eulerian elements in box type model wet drop simulation, it was also confirmed that the simulation results could more coincide with experimental ones, as the element size becomes smaller, the ratio of Lagrangian element size to Eulerian one, the same, air layers, more than four between box model and free surface, and the element of air layer, a regular hexahedron.