海洋结构物穿越波浪阶段的布放系统动力学问题研究

In the aim of deploying the offshore structures safely and reliably, it is necessary to analyze the dangerous working conditions during their lowering through wave zone in deployment process. In order to study the slamming effect between offshore structures and ocean wave,a three-dimension(3D) numerical wave tank is built by computational fluid dynamics(CFD) code, and the relationships between impact pressure and systematic parameters, including water entry velocity, acceleration, wave amplitude, wave frequency etc., are exhibited. By the theoretical analyses, the integrated dynamic model of deploying system is built and simulations are implemented by multibody dynamics code, and the coupling conditions of vessels and offshore structures are discussed. Moreover, combining with slamming analysis and integrated dynamic model of deployment system, a multibody dynamics-CFD integrated simulation platform is built. The virtual prototype model of the deployment system is established, and the dyanmic responses of the deployment system after slamming are studied on the simulation platform.Concerning on lifting load system and fluid motion of free water surface, the motion states and variations of deploying system with different systematic parameters and working conditions are investigated, and the analysis about dangerous working conditions are carried out. The experimental system of restrained rigid bodies impacting water is established and the accuracy of numerical models is validated. To sum up,this project has great theoretical and practical value, thus would provide a significant reference for studying the deployment system of marine structures and underwater installation.

为保证海洋结构物安全可靠地到达目标工作水域，必须对海洋结构物布放过程中的穿越波浪阶段所遭遇的危险工况进行分析。本申请采用计算流体力学方法构建三维数值波浪水槽，开展海洋结构物与波浪砰击的研究，探明入水相对速度、相对加速度、波幅和频率等参数与砰击载荷的关系与规律；通过理论分析，基于机械多体动力学，构建布放系统穿越波浪阶段的整体动力学模型，探讨船舶与被布放物体耦合作用的条件；在砰击研究和布放系统整体动力学模型基础上，开展机械动力学-计算流体力学耦合建模分析方法研究；建立布放系统虚拟样机模型，在数值求解分析平台上对砰击后布放系统动态响应展开研究；针对吊物系统和自由液面流体运动，探明不同系统参数和工况下的系统运动状态和变化规律，讨论危险工况发生的条件；搭建受约束刚体入水砰击试验系统，验证数值模型的准确性。本项目的研究具有重要理论意义和实际应用价值，将为海洋结构物布放系统和水下安装的研究提供重要参考。

布放作业的顺利进行是海洋结构物在水下正常工作的基础，为保证海洋结构物安全可靠地到达目标工作水域，必须对海洋结构物布放过程中的布放系统动力学问题进行研究。本项目以计算流体力学和多体动力学理论为基础，采用理论分析、仿真分析和试验验证等方法，研究了多种典型结构物的波浪砰击、入水阶段与深海布放中布放系统动态响应等问题。主要研究内容和结果包括：1、采用计算流体力学方法构建了三维数值波浪水槽，探讨了普遍适用的三维造波和消波方法；2、开展了海洋结构物与波浪砰击的研究，探明了入水相对速度、相对加速度、波幅和频率、相对波高(H/d)、相对板宽(B/L)等参数与砰击载荷的关系与规律；3、基于机械多体动力学理论，构建了布放系统穿越波浪阶段的整体动力学模型；4、在砰击研究和布放系统整体动力学模型基础上，将ADAMS和FLUENT进行联合，通过开发数据交互模块，构建了机械动力学-计算流体力学耦合分析软件平台，并对穿越波浪阶段布放系统动态响应展开研究；5、针对吊物系统和自由液面流体运动，探明了结构物水下质量、缆绳刚度等系统参数和多种工况下的系统运动状态，获得了浸没过程中结构物的速度、加速度及布放缆绳的拉力等主要参数的变化规律，讨论了危险工况发生的条件；6、以深海采矿集矿机为例，研究了深海布放中的系统动态响应问题，并对布放过程中的缆绳承受的动态张力及动态放大因子(DAF)的主要影响因素进行了探讨。7、搭建了受约束刚体入水砰击试验系统，验证了数值仿真方法的准确性。本项目的研究具有重要理论意义和实际应用价值，将为海洋结构物布放系统和水下安装的研究提供重要参考。