The Response Of Longitudial Motions And Loads Of Ship In Wave

When sailing on wave, the ship will encounter strong wave loads. Therefore, it is important to make a research of the wave loads which affect the ship considerably in terms of security and initial design. In marine hydrodynamics field, potential flow theories are widely used to predict the ship motions and wave loads. Among various potential theories, strip theory is the most popular one in that it can provide the predicted ship motions and wave loads with enough engineering accuracy that is very useful for design.In this paper, the main work is to calculate the motions and the wave loads a ship encounters when it sails against the wave. During the course of calculating the loads and hydrodynamics, I use the two-dimension linear potential flow theories. Meanwhile I also adopt the three-parameter Lewis section method to calculate the ship's hydrodynamics coefficients. Since the outline of the ship is of three dimensions, the data that I've gathered from the two-dimension theory must be processed according to the strip theory. Thus, I employ the new strip theory. According to the wave theory, the wave loads and the ship's motions have close relation and interaction with each other. Apart from the longitudinal motion in wave and the wave loads, I still calculate the wave-induced moment, slamming load, and at the same time predict the probability of the slam and the extreme value of the slam pressure.I've written the computer programs about calculating the hydrodynamics coefficients, the breadth of the longitudinal motion, wave induced moment, slamming pressure, slamming probability and predict the extreme value of the slamming pressure. The results are quite satisfying when I compare the data in this article with those in literature.