Analysing fluid-structure interaction with CFD and FEA on a marine double-wall LNG piping system

Abstract

In this study, the interaction of fluid-structure with Ansys Fluent and Structural was analysed on a double-wall LNG piping system in a marine ship. In terms of simulations, the inner tube of the double-walled tube on the TSR-18008 ship designed by SU Ar-Ge Dizayn ve Mühendislik A.Ş. is considered. Two different simulations were made; the first analysis was a computational fluid dynamics analysis and the results obtained from this were imported into the finite element analysis also known as structural analysis and the structural analysis was undertaken together using these data. The mesh used in the simulations has 2,985,116 elements and 2,135,093 nodes. The inlet velocity of the gas is 6.5 m/s and the temperature value is 108 K as boundary conditions. Seventeen cylindrical support elements are used to ensure the strength of the Liquefied Natural Gas pipe system. Three different pipe materials, which are structural steel, stainless steel, and aluminium alloy, have been considered for the numerical structural analysis. The highest stresses were observed at the elbows and results were given using various contours including stresses, strains, temperatures and streamlines in these elbows.