A high-order finite difference method with immersed-boundary treatment for fully-nonlinear wave–structure interaction. (May 2023)

• Record Type: Journal Article
• Authors: Xu, Yan; Bingham, Harry B.; Shao, Yanlin
• Is Part Of: Applied ocean research. Volume 134(2023)
• Publication Date: 2023-05
• Subjects: Finite difference method -- Immersed boundary method -- Potential flow -- Wave–body interaction -- Hyperviscosity filter; Ocean engineering -- Periodicals; 620.416205
• DOI: 10.1016/j.apor.2023.103535
• Languages: English
• ISSNs: 0141-1187

Abstract

Abstract: In order to predict nonlinear wave loading on marine structures, a fully nonlinear higher-order finite difference based potential flow solver with all boundary conditions treated by an immersed boundary method has been developed in this paper. The solver adopts high-order finite difference schemes for the spatial derivatives and a 4th order Runge–Kutta method for time stepping. Test cases of forced oscillation of a cylinder in an infinite fluid domain are first studied, which reveal the advantage of the acceleration potential method in terms of wave load computation. Then a wave generation problem using a piston type wave maker is tested. Special attention is paid to the intersection point between the free surface and the body surface, and a scheme which best meets the accuracy and stability requirements is suggested from several proposals. A novel hyperviscosity filter, which works for both uniform and non-uniform grids, is introduced to stabilize the time-domain solution of the wave maker problem. Finally, a forced heaving cylinder on the free surface is considered, and the nonlinear wave loads on the cylinder are analyzed and compared to benchmark results.