半潜平台内孤立波载荷特性数值模拟  

Numerical simulation for the load characteristics of internal solitary waves on the semi-submersible platform

作　　者：王旭[1] 林忠义[2] 尤云祥[1] 

机构地区：[1]上海交通大学海洋工程国家重点实验室,上海200240 [2]嘉兴南洋职业技术学院,浙江嘉兴314003

出　　处：《船舶力学》2015年第10期1173-1185,共13页Journal of Ship Mechanics

基　　金：国家自然科学基金资助(11372184);高等学校博士点基金资助(20110073130003)

摘　　要：以三类内孤立波理论KdV、e KdV和MCC的适用性条件为依据,采用Navier-Stokes方程为流场控制方程,将内孤立波诱导上下层深度平均水平速度作为入口边界条件,建立了两层流体中内孤立波对半潜平台强非线性作用的数值模拟方法。结果表明,数值模拟所得内孤立波波形及其振幅与相应理论和实验结果一致,并且在内孤立波作用下半潜平台水平力、垂向力及其力矩数值模拟结果与实验结果吻合。研究同时表明,半潜平台内孤立波载荷由波浪压差力、粘性压差力和摩擦力构成,其中摩擦力很小,可以忽略;水平力的主要成分为波浪压差力和粘性压差力,粘性压差力与波浪压差力相比较小却不可忽略,流体粘性的影响较小;垂向力中粘性压差力很小,流体粘性影响可以忽略。此外,半潜平台对内孤立波的波形及其诱导流场的影响很小,因此采用Morison和傅汝德—克雷洛夫力公式计算其内孤立波载荷是可行的。According to the applicability conditions for three type of internal solitary waves theories includ- ing KdV, eKdV and MCC, a numerical method based on the Navier-Stokes equation in a two-layer fluid is presented to simulate the strongly nonlinear interaction of internal solitary waves with a semi-submersible platform, where the velocity-inlet boundary is applied by using the depth-averaged velocities in the upper- and lower-layer fluids induced by the internal solitary waves. The results show that the waveforms and am- plitudes of the internal solitary waves based on the present numerical method are in good agreement with the experimental and theoretical results, and the numerical results for the horizontal and vertical forces, as well as torques on the semi-submersible platform due to the internal solitary waves have good agreement with experimental results. It is shown that the horizontal and vertical forces on the semi-submersible plat- form due to the internal solitary waves can be divided into three components which are the wave and vis- cous pressure forces, as well as the frictional force, where the frictional force is small and can be neglected. For the horizontal force, their main components are wave pressure and viscous pressure forces, where the viscous pressure force is small but can not be neglected. For the vertical force, the component of the viscousthe semi-submersible platform due to internal solitary waves can be calculated by the Morison equation and Froude-Krylov force.

关 键 词：两层流体 内孤立波 半潜平台 载荷特性 

分 类 号：P751[交通运输工程—港口、海岸及近海工程]