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Assessment on the coastal environment by wash caused by a ship and its application

船舶冲刷海岸环境评价及其应用

基本信息

批准号：
14350520
负责人：
DOI Tasuaki
金额：
$ 7.55万
依托单位：
HIROSHIMA UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2003
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14350520/
关键词：
coastal erosion wash wave breaking level set method 孤立波浅水狭水路水深変化

项目摘要

In the present study, numerical method to investigate wash mechanism by high speed ship in restricted waterway including wave breaking was developed and the assessment was given on the effect of wash by the numerical investigation. Incompressible Navier-Stokes and continuity equations were employed for the numerical simulation. The equations were discritized by finite difference method in curvilinear coordinates system. Interface capturing method was applied for the simulation of ship waves including wave breaking. Modification of level set method was proposed to find the free surface shape clearly. In order to obtain high resolution of wave height, Cubic Interpolated Pseudo particle (CIP) algorithm was adopted. The computations in restricted waterways were performed and good agreement with experiments was obtained. Experiments to find unsteady effect due to water depth change in restricted waterway were also conducted. Through the numerical and experimental study, the significant factors from the viewpoint of wave height in narrow waterway were described. The numerical method is also applied to the analysis of wash characteristics on shore. Through the examination of computed flow field, the wave breaking phenomena, mixing the run-up and run-down wave, generation of vortical flow, were understood and large velocity vectors on shore and negative pressure on the shore, which are expected to affect the beach erosion, were observed. Finally, through the computation for different configuration of waterway, the assessment was given related with the characteristics of ship wave and waterway configuration.

本文建立了高速船舶在受限航道中的冲浪机理的数值研究方法，并通过数值研究对高速船舶在受限航道中的冲浪作用进行了评价。数值模拟采用不可压Navier-Stokes方程和连续性方程。在曲线坐标系中用有限差分法对方程进行了离散。采用界面捕捉法对包含破波在内的船舶波浪进行了数值模拟。提出了对水平集方法的改进，使自由面形状更清晰。为了获得高分辨率的波高，采用了三次插值伪粒子（CIP）算法。在限制性水道中进行了计算，并与实验取得了良好的一致。并进行了水深变化对非定常流影响的试验研究。通过数值计算和试验研究，从波高的角度阐述了狭窄水道中的重要影响因素。本文还将数值方法应用于海岸冲刷特性的分析。通过对计算流场的检验，了解了波浪破碎、上升波和下降波的混合、涡流的产生等现象，并观察到海岸上的大速度矢量和海岸上的负压，这些都将影响海滩的侵蚀。最后，通过对不同航道布置形式的计算，结合船舶兴波特性和航道布置形式，给出了相应的评价。