|As the International Maritime Organization (IMO) significantly tightens the emission gas regulations for ships, ships using Liquefied Natural Gas (LNG), which is an eco-friendly fuel, are attracting attention. Accordingly, the demand for LNG offloading operations in which Floating Liquefied Natural Gas (FLNG) delivers LNG to an LNG carrier is increasing in the process of LNG production. Meanwhile, for safe operation, dynamic analysis is required in advance, and safety regulations should be established. However, the analysis of the LNG offloading operation is very complex as ships are connected with offloading arms, which consists of several bodies and joints. Furthermore, the hydrodynamic interaction between the floating bodies should be considered at the same time. In this study, the dynamic analysis of LNG offloading operations with FLNG and LNG carrier considering the interaction of two floating bodies was conducted, and the joint forces exerted on the offloading arms were analysed. Firstly, the multibody dynamics-based equations of motion were formulated for the analysis of the offloading arms. Subsequently, the external forces due to the hydrodynamic interaction of two floating bodies were calculated in the time domain and integrated with the multibody dynamics. Finally, the coupled analysis of the ships and the offloading arms were performed according to the various parameters of the offloading arms, such as the number, position, and length. As a result, the dynamic load acting on the joints of the offloading arms were analysed under the various environmental conditions, and the safety regulations for the offloading operation were derived.
Hye-Won Lee, Myung-Il Roh, Seung-Ho Ham, Bo-Woo Nam, "Coupled Analysis of the LNG Offloading Operation Based on Multibody Dynamics", Proceedings of International Symposium on PRADS(Practical Design of Ships and Other Floating Structures) 2022, Dubrovnik, Croatia, 2022.10.09-13