A fully nonlinear wave interaction with an array of submerged cylinders by NURBS numerical wave tank and acceleration potential

A numerical wave tank (NWT) is developed to study fully nonlinear wave interaction with a fixed submerged single cylinder, dual cylinders and cylinder arrays. The high-order boundary element method (BEM) based on non-uniform rational B-spline (NURBS) is used to obtain the boundary values in the Eulerian frame. The material node approach is used to trace the free surface particles in the Lagrangian manner. The fourth-order Runge-Kutta time integration scheme is applied to update the boundary values and positions. Spatial derivatives of boundary values are also computed by NURBS. To evaluate the hydrodynamic pressure on the objects, the time derivative of the velocity potential is calculated by the acceleration potential formulation. Hydrodynamic forces on a single cylinder and dual cylinders are computed and compared with the experimental measurement and former numerical simulations. For arrays of cylinders, free surface elevation is obtained and diffraction problems are solved.