A Study on Predictions of Fully Nonlinear Motion Aircushion Type Floating Structures Using 2D MPS Method
A Study on Predictions of Fully Nonlinear Motion Aircushion Type Floating Structures Using 2D MPS Method
复制标题
基于二维MPS方法的全非线性运动气垫式漂浮结构预测研究
作者：
M. Masuda;T. Ikoma;K. Masuda;H. Maeda
超大型浮式结构物（VLFS）作为一种新的海洋空间利用方式被提出并进行了大量的研究。VLFS由于海浪而弹性变形，因为结构的刚度相对降低。为了减少水弹性运动，作者研究了气垫式浮动结构。安装有空气室的气垫式漂浮结构可以同时减小波浪漂移力和水弹性运动。迄今为止，气垫式浮体在波浪中运动的理论计算大多是基于线性势理论。结果证明了气垫的实用性。然而，完全非线性的现象，如甲板潮湿，砰击和空气泄漏不能使用现有的计算的基础上的线性理论进行研究。本文首先编制了一个能充分考虑非线性影响的二维MPS方法的计算机程序，然后用MPS中的粒子来表示气垫内的空气层。此外，还发展了将系泊力直接引入质点运动方程的数值方法。计算了气垫式浮体在波浪中的运动响应。结果证实了该数值计算方法的有效性。Copyright © 2008 by ASME
Very large floating structures (VLFSs) have been proposed for new ocean space utilization and many researches have been carried out. VLFSs are elastically deformed due to ocean waves because the rigidity of the structure decreases relatively. The authors examine the aircushion type floating structure in order to reduce hydroelastic motion. An aircushion type floating structure to which air-chambers are installed can reduce the wave drifting force and hydroelastic motion at the same time. Most theoretical calculations of motion of aircushion type floating structures in water waves have been done based on a linear potential theory so far. As a result, the utility of the aircushion has been proved. However fully nonlinear phenomena such as deck wetness, slamming and air-leakage cannot be investigated by using existing calculations based on the linear theory. In this study, a computer program code of the two-dimensional MPS method that can consider fully nonlinear influence is developed and then the air layer inside an aircushion is expressed with particles of the MPS. Moreover, the numerical technique for introducing directly the mooring force into the motion equation of the particle is developed. Motion response of aircushion type floating structures in a billow is computed. As a result, the usefulness of this numerical calculation method is confirmed.Copyright © 2008 by ASME