Time Domain Simulation of Steady ShipWave Problem by a Higher-Order Boundary Element Method

摘要

A 3-D time-domain numerical wave tank using a higher-order boundaryelement method is newly developed in the framework of linear potentialtheory, and ship waves generated by the standard Wigley modeladvancing at constant forward speed in otherwise calm water and theresultant steady wave resistance are computed as verification of the computercode developed. A rectangular computational domain moving withthe same forward speed as the ship is introduced, in which an artificialdamping beach is installed at an outer portion of the free surface exceptthe downstream side for satisfying the radiation condition. The velocitypotential on the ship hull and the normal velocity on the free surfaceare obtained directly by solving the boundary integral equation, with theRankine source used as the kernel function. For numerical stability andaccuracy, an iterative time-marching scheme is employed for updatingboth kinematic and dynamic free surface boundary conditions. Thus theboundary integral equation is solved at each time stepping. After validatingthe convergence with respect to time step and mesh size, the problemfor computing the steady waves generated by the Wigley hull is consideredas an initial-value problem, increasing the ship’s speed from a stateof rest up to a specified constant value. Computed results of the wave patternand wave resistance are illustrated and compared with experimentalmeasurements, showing satisfactory agreement.