Numerical Research Of Wake Waves Of Ships Loads On Vertical Walls

With the rapid progress of high-speed vessels, the speeding up of waterway transportation is one of the main tendencies of modern transportation. However, the higher wake wave is a common problem of the domestic high-speed ships. Severe wake waves would threaten the safety of the smaller ships, and cause environmental damages. Researches on the wave-making and wake-wave propagation of high-speed ships are theoretically challenging and have attracted attention of marine engineers.The Vertical-wall building is a structural type which is in common used in the harbor and coastal engineering. The breaking wave has a strong impact pressure on the walls and the mechanism of breaking wave is very complicated. As for the interaction of breaking wave and vertical wall, there is no rigorous theory to calculate the force until now. The traditional method in practical engineering is based on experiential formulas. As the study of the impact of ship waves on the wharf, the scientific research of the ship waves in different hull forms is rare.A combined near/far-field method is used to calculate the wake waves of high-speed displacement vessels in the far-field.The first-order Rankine-source panel method is employed in the near-field calculations. The hull surface and part of free surface are discretized by quadrilateral panels. Under corresponding boundary conditions, the source strengths are solved and then the linear Kelvin wave pattern obtained through the velocity potential determined by the source strengths solved. Raised panels above the free surface combined with collocation-point shifting up-stream are used to satisfy the radiation condition numerically.At a certain distance away from the hull, the ship waves can be regarded as harmonic waves, so the far-field wake waves can be then determined numerically by one-variable function called wave amplitude spectrum. The wave amplitude spectrums could be determined through wave pattern analysis for the corresponding calculated near-field waves, and far-field wake waves are then obtained numerically.Wigley hull and NPL hull are selected as computational examples. The far-field wave patterns in deep water are computed respectively. The wave-making resistance and wake-waves of high-speed displacement ships, mono-hull, catamaran and trimaran in shallow water are computed. The result is then used to calculate the force of ship waves on the wharf.