Numerical Study on Wave-induced Motion of Offshore Structures Using Cartesian-grid based Flow Simulation Method |
Nam Bo Woo,Kim Yonghwan,Yang Kyung Kyu,Hong Sa Young,Sung Hong Gun |
Ocean Plant Research Department MOERI/KIOST,Seoul National University,Seoul National University,Ocean Plant Research Department MOERI/KIOST,Ocean Plant Research Department MOERI/KIOST |
직교 격자계 기반 유동해석기법을 이용한 파랑 중 해양구조물의 운동 해석 |
남보우,김용환,양경규,홍사영,성홍근 |
한국해양과학기술원 해양플랜트연구부,서울대학교 산업조선공학부,서울대학교 산업조선공학부,한국해양과학기술원 해양플랜트연구부,한국해양과학기술원 해양플랜트연구부 |
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© 2012 The Korean Society of Ocean Engineers
Open access / Under a Creative Commons License
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Keywords:
Offshore Structure, Cartesian-grid, Wave-induced Motion, Flow Simulation Method, Wave excitation force, Added mass, Wave damping |
핵심용어:
해양구조물, 직교 격자계, 파랑운동, 유동해석기법, 파랑 기진력, 부가질량, 파랑 감쇠 |
Abstract |
This paper presents a numerical study of the wave loads acting on offshore structures using a Cartesian-grid-based flow simulation method. Finite volume discretization with a volume-of-fluid (VOF) method is adopted to solve two-phase Navier-Stokes equations. Among the many variations of the VOF method, the CICSAM scheme is applied. The body boundary conditions are satisfied using a porosity function, and wave generation is carried out by using transient (wave or damping) zone approaches. In order to validate the present numerical method, three different basic offshore structures, including a sphere, Pinkster barge, and Wigley model, are numerically investigated. First, diffraction and radiation problems are solved using the present numerical method. The wave exciting and drift forces from the diffraction problems are compared with potential-based solutions. The added mass and wave damping forces from the radiation problems are also compared with the potential results. Next, the wave-induced motion responses of the structures are calculated and compared with the existing experimental data. The comparison results are fairly good, showing the validity of the present numerical method. |
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