Hydroelastic analysis of insulation containment of LNG carrier by global–local approach

Abstract

SUMMARYThe insulation containment of liquefied natural gas (LNG) carriers is a large-sized elastic structure made of various metallic and composite materials of complex structural composition to protect the heat invasion and to sustain the hydrodynamic pressure. The goal of the present paper is to present a global-local numerical approach to effectively and accurately compute the local hydroelastic response of a local containment region of interest. The global sloshing flow and hydrodynamic pressure fields of interior LNG are computed by assuming the flexible containment as a rigid container. On the other hand, the local hydroelastic response of the insulation containment is obtained by solving only the local hydroelastic model in which the complex and flexible insulation structure is fully considered and the global analysis results are used as the initial and boundary conditions. The interior incompressible inviscid LNG flow is solved by the first-order Euler finite volume method, whereas the structural dynamic deformation is solved by the explicit finite element method. The LNG flow and the containment deformation are coupled by the Euler-Lagrange coupling scheme.

Multitechnique Concise Robust Control for the Insulation Containment Space Pressure Control of LNG Carrier

“…In the pressure maintenance system of the LNG carrier CCS, the disturbance is mainly from two parts, the pressure change caused by the adjustment of other valves and the volume change of the insulation space caused by the sloshing of liquid tanks [11,30]. e former kind of disturbance can be represented by the step signal, and the latter can be represented by the white noise.…”

Dynamic response of floating substructure of spar-type offshore wind turbine with catenary mooring cables

“…A two-step predictor-corrector method (Cong, 1996;Kim and Kim, 2001) is used for the time integration of the equations of motion. The Euler-Lagrange-type coupling method is employed to deal with the interaction between the rigid body structure motion and the water flow, and it with the lapse of time is numerically implemented in a staggered iterative manner (Sigrist and Abouri, 2006;Cho et al, 2008). The hydrodynamic pressure of water flow acts as the external force and moment for both the floating substructure and mooring cables, and then the rigid body movement of floating substructure relocates the flow-structure interface.…”

“…Sea water is assumed to be potential flow by neglecting the viscosity and compressibility, and the time histories of irregular wave are generated using the Pierson-Moskowitz spectrum (1964). The wave-floating substructure and wave-mooring cable interactions are simulated by the coupled BEM-FEM methods in the staggered iterative approach (Cho et al, 2008). Through the numerical experiments, dynamic responses of cylindrical floating substructure and mooring cables are investigated with respect to the length and connection position of mooring cables and to location of the center of mass of floating substructure.…”