Session: 08-02-02 Ship & Floating Systems

Paper Number: 104833

104833 - Effect of Wind Speed Profile on Wind Loads of Liquefied Natural Gas Fpsos 

Marine accidents involving ships and offshore installations, caused by a loss of stability, have been increasing over the last decade. One of the main reasons for these accidents is a sudden wind attacks. In this regard, the wind loads acting on the offshore structures need to be estimated accurately for safety assessments of the motion and maneuverability of the ship. Therefore, this study aims to develop a computational model for the inlet boundary condition and to numerically estimate the wind load acting on offshore structures. In particular, wind loads acting on the Liquefied Natural Gas FPSOs at the wind speed profile boundary condition were compared with the numerical results obtained under uniform wind speed. The wind loads were estimated at intervals of 15° over the range of 0° to 180°, and i.e., a total of 13 cases. Furthermore, a numerical mesh model was developed based on the results of the mesh dependency test. The numerical analysis was performed using the RANS-based commercial solver STAR-CCM+ (ver. 17.02) with the k-omega turbulent model in the steady state. The wind loads for 6DOF motions were changed dramatically, as compared with the values under uniform wind speed. It was confirmed that the developed inlet boundary condition describing the wind speed gradient with respect to height features higher accuracy than the boundary condition of uniform wind speed. The insights obtained in this study can be useful for the development of a numerical computation method for offshore installations.

Presenting Author: Sang-Eui Lee Changwon National University

Presenting Author Biography: Dr. Sang Eui Lee is an assistant professor at Changwon National University since September 2018. He was a postdoctoral research fellow in the Southampton Marine and Maritime Institute at the University of Southampton from September 2017 to August 2018 & in The Korea Ship and Offshore Research Institute (KOSORI) at Pusan National University (PNU) in Korea from March 2015 to August 2018. His research career had been started in March 2004 as a master's student at PNU. After two years, a variety of experimental tests in hydrodynamics such as maneuverability of underwater vehicles, motion analysis of very large container carriers, the effect of anti-roll tanks on ship motion, and ship motion analysis under irregular waves had been experienced. Dr. Lee received two best paper awards from both Korea Institute of Navigation and Port Research and KTTC, an affiliated organization of The Society of Naval Architects of Korea.

Authors:

Byung-Hyuk Lee Korea Shipbuilding & Offshore Engineering Co.
Sang-Eui Lee Changwon National University