Solitary wave-current forces on a horizontal cylinder by a fourth-order-accurate finite volume compact solver

This study utilizes a fourth-order-accurate finite volume compact solver to simulate the interaction between solitary waves, uniform currents, and a horizontal cylinder near the free surface. The interactions of a horizontal cylinder with solitary waves only, solitary waves-following currents, solitary waves-opposing currents are investigated. The study delves into the characteristics of fluid-induced forces on the cylinder, dynamic pressure surrounding the cylinder as the wave crest passes its center, pressure distribution over time as wave travels across the cylinder, and vorticity behaviors under the three typical conditions. The effects of wave height and current velocity are concerned. The employed numerical solver is an in-house code that solves the Navier-Stokes equations using a finite volume method on a collocated grid. The free surface is represented by a volume of fluid method, and the cylinder is captured by a ghost cell immersed boundary method. The solver's accuracy is confirmed against the experimental data of flow velocities in a solitary wave and current interaction. The results reveal a clear correlation between the vertical forces on the cylinder and the current velocity in cases of wave-following current interactions, but it is unclear in cases of wave-opposing current interactions due to the complex vortex behaviors involved.