Development of a Three‐Dimensional Fully Nonlinear Potential Numerical Wave Tank for a Heaving Buoy Wave Energy Converter

Abstract

The hydrodynamic performance of a vertical cylindrical heaving buoy-type floating wave energy converter under large-amplitude wave conditions was calculated. For this study, a three-dimensional fully nonlinear potential-flow numerical wave tank (3D-FN-PNWT) was developed. The 3D-FN-PNWT was based on the boundary element method with Rankine panels. Using the mixed Eulerian–Lagrangian (MEL) method for water particle movement, nonlinear waves were produced in the PNWT. The PNWT can calculate the wave forces acting on the buoy accurately using an acceleration potential approach. The constant panels and least-square gradient reconstruction method were applied to regridding of computational boundaries. An artificial damping zone was employed to satisfy the open-sea conditions at the end free surface boundaries. The diffraction and radiation problems were solved, and their solutions were confirmed by a comparison with previous studies. The interaction of the incident wave, floating body, and power take-off (PTO) behavior was examined in the time domain using the developed 3D-FN-PNWT. From comparison, the difference between the conventional linear analysis and the nonlinear analysis in large-amplitude waves was examined.

Numerical Study on Wave Run-up of a Circular Cylinder with Various Diffraction Parameters and Body Drafts

“…where  denotes a three-dimensional angle, and  denotes the kernel function. The three-dimensional basic Rankine source expression in 3D is , where  denotes the distance between the source and field points (Kim and Koo, 2019).…”

“…The least square technique is employed for reconstructing the gradient for spatial differentiation, and the inverse distance weighting (IDW) method is employed for interpolation of the nodes. Further details can be found in Kim and Koo (2019).…”

“…Bai and Eatock Taylor (2007) In this study, a wave run-up phenomenon that acts on a cylinder having a circular cross section, which is a typical shape for a marine structure column, was studied using a three dimensional NWT. To this end, the three-dimensional fully nonlinear potential NWT technique developed by Kim and Koo (2019)…”

Fully nonlinear dynamics of floating solar platform with twin hull by tubular floaters in ocean waves

“…The Mixed Eulerian-Lagrangian (MEL) approach coupled with a high-order time integration scheme has been employed for time marching the fluid particle on the free surface and updating the fully nonlinear free surface boundary conditions for the next time step. The MEL method has been implemented using the material node approach discussed in (Abbasnia and Guedes Soares, 2020) and the semi-Lagrangian scheme (Kim and Koo, 2019). To solve the equation of body motions, various methodologies have been proposed to calculate the instantaneous hydrodynamic pressure on the exact wet surface.…”

“…To solve the equation of body motions, various methodologies have been proposed to calculate the instantaneous hydrodynamic pressure on the exact wet surface. An acceleration potential formulation (Vinje and Brevig, 1981) based upon the modal decomposition method can obtain the time derivative of the velocity potential field on the instantaneous wet surface implicitly; for instance Coslovich et al (2021); Ganesan and Sen (2019); Kim and Koo (2019). The implicit body boundary condition algorithm was implemented by Abbasnia and Guedes Soares (2017) to calculate the responses of a ship-shaped freely floating body under strong nonlinear incident waves.…”