Time-Domain Analysis of Steady Ship-Wave Problem Using Higher-Order BEM

A 3-D time-domain numerical wave tank using a higher-order BEM (Boundary Element Method) is newly developed in the framework of linear potential theory, and ship waves generated by the standard Wigley model advancing at constant forward speed in otherwise calm water and the resultant steady wave resistance are computed as verification of the computer code developed. A rectangular computational domain moving with the same forward speed as the ship is introduced, in which an artificial damping beach is installed at an outer portion of the free surface except the downstream side to satisfy the radiation condition. The velocity potential on the ship hull and the normal velocity on the free surface are obtained directly by solving the boundary integral equation, with the Rankine source used as the kernel function. For numerical stability and accuracy, an iterative time-marching scheme is employed for updating both kinematic and dynamic free surface boundary conditions. Thus, the boundary integral equation is solved at each time step. After convergence studies, the problem for computing the steady waves generated by the Wigley hull is considered as an initial-value problem, increasing the ship’s speed from a state of rest up to a specified constant value. Computed results of the wave pattern, wave profile along the hull, pressure distribution on the hull, and wave resistance are illustrated and compared with experimental measurements, showing satisfactory agreement.