Numerical Investigation of Hydroelasticity Effects on Floating Structures
Changqing Jiang, University of Duisburg-Essen
Ould el Moctar, University of Duisburg-Essen
Yan Qi, University of Duisburg-Essen
Hydroelasticity effects of an offshore floating structure concern the combined motions and deformations of the floating body responding to environmental excitations. The review of research on hydroelasticity of very large floating structure (VLFS) shows that understanding of the physical phenomenon has been increased but discussions of practical implications of hydroelasticity to offshore structure design are rare.
Conventionally, floating structures are designed based on rigid-quasi-static analysis, meaning that the hydrodynamic loads are estimated under rigid assumption and then applied to the elastic structure regardless of the structural inertia. In this research, the hydroelastic behavior of a standard floating module designed in the scope of Space@Sea project was numerically investigated, and the role of hydroelasticity in practical assessment of large floating structure performance was demonstrated. The fluid dynamics relies on a Computational Fluid Dynamics (CFD) code, and the structural responses is computed by a coupled Computational Structural Dynamics (CSD) solver. The CFD-CSD solver is coupled using an implicit two-way coupling approach, computing the nonlinear 6-DoF rigid body motion separately from linear elastic structural deformations.
Firstly, the numerical model was validated against available benchmark, and then the standard floating module in waves was assessed in terms of structural integrity and motions. Maximum stress and bending moment obtained by the coupled CFD-CSD approach and traditional rigid-quasi-static approach are compared, and the implication of the hydroelasticity in the floating module was discussed. Based on the hydroelastic criterion, validity range of rigid-quasi-static analysis and the importance of dynamic response are determined.
Keywords – Hydroelasticity, Floating Structure, CFD, CSD
Changqing Jiang is a research assistant within the Institute of Ship Technology, Ocean Engineering and Transport Systems (ISMT) at University of Duisburg-Essen. His research mainly focuses on the wave-structure interaction, hydroelastic response of moored offshore structures.
He received a B.Eng. in Naval Architecture and Ocean Engineering from Zhejiang Ocean University, and an M.Eng. in Marine Technology from Tokyo University of Marine Science and Technology.