Numerical Simulation of Wave Forces acting on Fixed Offshore Structures Using Hybrid Scheme

J. Ocean Eng. Technol. 2010;24(6):16-22.

Nam Bo-Woo,Hong Sa-Young,Kim Yong-Hwan

Marine Structure & Plant Research Department MOERI/KORDI,Marine Structure & Plant Research Department MOERI/KORDI,Dept. of Naval Architecture and Ocean Engineering Seoul National University

하이브리드 기법을 이용한 고정된 해양구조물에 작용하는 파랑하중에 관한 수치 시뮬레이션

남보우,홍사영,김용환

한국해양연구원 해양시스템안전연구소 해양구조물.플랜트연구부,한국해양연구원 해양시스템안전연구소 해양구조물.플랜트연구부,서울대학교 공과대학 조선해양공학과

Keywords: Hybrid scheme, Wave force, Finite volume method (FVM), Volume-of-fluid (VOF) method

핵심용어: 하이브리드 기법, 파랑력, 유한체적법, VOF법

Abstract

In this paper, the diffraction problems for fixed offshore structures are solved using a hybrid scheme. In this hybrid scheme, potential-based solutions and the Navier-Stokes-based finite volume method (FVM) with a volume-of-fluid (VOF) method are combined. We introduce a buffer zone for efficient wave-making and damping. In this buffer zone, the near field solution from FVM-VOF is gradually changed to Stokes' 2nd order wave solutions. Three different models, including the truncated cylinder, sphere, and wigleyIII model, are numerically investigated in regular waves with a wave steepness of 1/30. The efficiency and accuracy of the hybrid scheme are numerically validated from results using different domain sizes and buffer zones. The wave exciting forces from the FVM-VOF simulations are compared with experiments and potential-based solutions from the higher-order boundary element method (HOBEM). This comparison shows good agreement between the hybrid scheme and potential-based solutions.