半潜平台内孤立波载荷实验及其理论模型研究  

The experiments of internal solitary wave loads and their theoretical model for a semi-submersible platform

作　　者：黄文昊[1] 尤云祥[1] 石强 王竟宇[1] 胡天群[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]大连船舶重工集团设计研究所有限公司,大连116021

出　　处：《水动力学研究与进展（A辑）》2013年第6期644-657,共14页Chinese Journal of Hydrodynamics

基　　金：国家高技术研究发展计划(863项目;2010AA09Z305);高等学校博士点基金项目(20110073130003)~~

摘　　要：该文在大型重力式密度分层水槽中,对内孤立波作用下半潜平台的载荷特性开展了系列实验。基于两层流体内孤立波KdV、eKdV和MCC理论,建立了半潜平台内孤立波载荷的理论预报模型,给出了该理论预报模型中三类内孤立波理论的适用性条件。研究表明,半潜平台的内孤立波水平力包括立柱与横撑部分的拖曳力、惯性力以及沉箱部分的Froude-Krylov力三个部分,其中前两个力可由Morison公式进行计算,第三个力可以通过内孤立波诱导动压力在沉箱迎流和背流面进行积分计算。半潜平台的垂向力主要为垂向Froude-Krylov力,可以通过内孤立波诱导动压力在横撑和沉箱上下表面进行积分计算。系列实验结果表明,在Morison公式中的拖曳力系数与内孤立波诱导速度场的雷诺数之间为指数函数关系,惯性力系数与KC数之间为幂函数关系,而且基于所建立理论预报模型所获半潜平台水平力、垂向力及其力矩的计算结果均与系列实验结果吻合良好。Series experiments are conducted to investigate loads characteristics of internal solitary waves with a semi-submersible platform in a large-scale gravity type density stratified tank. Based on KdV, eKdV and MCC theories for internal solitary waves in a two-layer fluid, a theoretical model is established for predicting the internal solitary wave loads on a semi-submersible platform, and the applicability conditions for these internal solitary wave theories are presented in order to apply such a loads model. It is shown that the horizontal loads on the semi-submersible platform due to the internal solitary wave consist of three parts： drag and inertial forces on the vertical column and cross-brace, which can be determined by the Morison formula, as well as Froude-Krylov force on the caisson which can be obtained by integrating the dynamic pressure induced by the internal solitary wave along with the forward and backward surfaces of the caisson respectively. While the vertical load is mainly the vertical Froude-Krylov force which can be calculated by integrating the dynamic pressure along with the upper and lower surfaces of the cross-brace and caisson. Series experimental results show that the drag coefficient in the Morison formula follows some exponential function relationships with the Reynolds, while the inertial force coefficient follows power function relationships with KC numbers. Moreover, the numerical results based on the theoretical predicting model have good agreement with experimental ones. The investigation provides a practical theoretical model on the basis of the series experiment results for predicting internal solitary wave loads on semi-submersible platforms.

关 键 词：两层流体 半潜平台 内孤立波 Morison公式 Froude-Krylov力 

分 类 号：O352[理学—流体力学]