船艏底部砰击压力概率预报方法研究

在Ochi概率统计方法的基础上探索一种适合于非常规船型船艏底部砰击压力的概率预报方法。该方法在时域中计算船舶在波浪中的运动响应,基于Msc.Dytran计算砰击压力系数,在此基础上采用蒙特卡罗法对砰击压力的概率特性进行预报。分析了砰击时的船波相对速度和波面倾角对压力系数的影响。研究结果表明,船舶在静水和波浪中的砰击压力特性有很大差异,在波峰与波谷处发生砰击时产生的砰击压力大于在波面其它位置产生的压力值,相对速度对砰击压力系数的影响在波面不同位置呈现出不同的特点。

Research on Probabilistic Prediction Method of Ship Bottom Slamming

Based on the probabilistic method proposed by Ochi,this paper develops a method which could predict slamming pressure directly for the vehicle whose lines plan is unconventional.In this method the ship’s motion response is calculated in time domain when it sails in the wave,and the slamming coefficient is calculated through the software Msc.dytran.Then the characteristic of slamming pressure is predicted with Monte Carlo method based on the above results.The effect of relative velocity between the ship and the wave at the time of slamming and wave slope angle on the slamming coefficient is analyzed particularly.Research result shows that there is a great difference in characteristic of slamming pressure between the impact in still water and that in wave.The slamming which occurs at the peak and the trough of a wave will generate higher pressure.The effect of relative velocity between the ship and the wave on the slamming coefficient varies with different waves.