OpenFOAM을 이용한 catenary 계류시스템의 준정적 해석 프로그램 개발

Abstract

Generally, global performance analysis in offshore platforms is calculated by potential based numerical tools which neglect hydrodynamic viscous effects. In comparison with potential theory, CFD(Computational Fluid Dynamics) methods can take into account viscous effects by solving the Navier-stokes equation using the finite-volume method. For the FVM(Finite Volume Method) numerical analysis, the Open-source Field Operation and Manipulation(OpenFOAM) C++ libraries are employed. In this study, in order to apply CFD for global performance analysis of a hull-mooring coupled system, we have developed a numerical wave basin to analyze global performance problem of a floating body with catenary mooring system under regular wave condition. Mooring system is modeled using catenary equation and it is solved in quasi-static condition which excludes dynamics of mooring lines such as inertia and drag effects. To demonstrate the capability of a numerical basin, the global performance of a barge with 4 mooring lines was simulated under regular wave conditions. The simulation results were compared to the measurements from the model tests carried out in two dimensional wave basin in KMOU(Korea Maritime and Ocean University) and analysis results from a commercial mooring analysis program, Orcaflex. The comparison includes wave elevation, motion of the barge, tension in mooring lines. The study concludes a good agreement between results from developed CFD-based numerical calculation, model tests, and commercial software.