近年来，生态水域尤其是海洋的漂浮垃圾污染已成为备受关注的重大经济政治环境议题。当前世界各国已对江河湖泊的漂浮垃圾收集提出了诸多发明及对策，但在海洋中却缺少相应的可行方案，可见开发一种可靠高效的海洋水面垃圾收集装置已经成为了亟需解决的问题。本文针对实际需求，首先提出了一种新型的漂浮式水面垃圾收集装置（Shallow-sea Floating Surface Litter Collection Device；SFSLCD），为江河湖泊及浅海（水深5-15 m）的水面垃圾收集提供了一种适用广泛、安全可靠的收集方案。然后，分别应用势流理论及莫里森方程计算其受到的波浪惯性力、建立数值模型，对比两种模型水动力特性的异同并分析原因；深入分析辐射效应、拖曳力、系泊系统对整体阻尼的贡献。在最后，利用中国深圳市大鹏湾的沿海条件，验证了SFSLCD在多种海况下的可行性和安全性，以及其良好的运动性能。本文的研究范围主要包括以下几个方面：（1）提出SFSLCD的完整设计，包括基本组成、尺寸及关键参数、工作机制、系泊系统。该自流式装置能够利用水位差使得水域表层水体与水面垃圾自行流入，并将水面垃圾留在内部，从而实现水面垃圾收集。SFSLCD的优化设计吃水深度为2.52 m，质量为46921 kg。 （2）分别应用势流理论与莫里森方程计算SFSLCD受到的波浪惯性力、建立两种数值模型。比较两种模型的水动力特性计算结果并分析出现差异的原因，最终认为“势流理论惯性力+莫里森方程拖曳力”模型的计算结果更为准确可靠。分析研究了辐射效应、拖曳力、系泊系统对整体阻尼的贡献，发现阻尼主要来源于莫里森拖曳力，符合本浮体细长构件多的特征。（3）以深圳市大鹏湾为设计海域，对SFSLCD工作状态及自存状态下的数值模型进行了规则波、随机波、波流耦合工况的动力响应时域模拟，并对模拟结果做全面分析。结果表明，SFSLCD具备良好的运动性能。正常海况下的运动响应适中，满足垃圾收集的工作条件；恶劣海况下的运动响应相对较大，但系泊缆满足强度校核，能够保证SFSLCD的安全性。
In recent years, the pollution of ecological waters, especially the litter floating on the ocean surface, has emerged as a pressing economic, political, and environmental concern of the international society. While many inventions and countermeasures have been proposed for the collection of floating litter in rivers and lakes around the world, there is a lack of feasible solutions for the oceans. This makes the development of a reliable and efficient marine surface litter collection device an urgent problem. In this paper, a new shallow-sea floating surface litter collection device (SFSLCD) is proposed for the collection of surface litter in rivers, lakes, and shallow seas (5-15 m depth). This device provides a widely applicable, safe and reliable solution. Then, the potential flow theory and the Morison equation are applied to calculate the respective inertia forces and to establish numerical models. The differences and similarities in the hydrodynamic characteristics of the two models are compared and analyzed. Furthermore, the contribution of radiation effect, drag force, and mooring system to the overall damping is analyzed in depth. Finally, the safety of SFSLCD in normal and rough sea states is validated in terms of its good seakeeping performance using the coastal condition of Dapeng Bay, Shenzhen, China. The research scope in this study covers the following aspects:(1) The complete design of SFSLCD is presented, including the basic components, dimensions and key parameters, working scheme and mooring system. The self-flowing device uses the difference in water level to allow the surface water to flow in with the surface litter and leave the surface litter inside, thus enabling the collection of surface litter. SFSLCD has an optimized design draft of 2.52 m and a mass of 46,921 kg.(2) The potential flow theory and the Morison equation are applied to calculate the respective inertia force and to establish two numerical models. The results of the two models are comparable and the reasons for the small differences are given. It is concluded that the "potential flow theory inertia force + the Morison equation drag force" model is more accurate and reliable. The contribution of radiation effect, drag force, and mooring to the overall damping of the system is analyzed, and it is revealed that the damping mainly comes from the Morison drag force, which is in line with the characteristics of slender structural members of the device.(3) Using Dapeng Bay in Shenzhen as the design sea area, time domain simulations of the dynamic response of SFSLCD in the working state and self-survival state are carried out for regular waves, random waves, and wave-current coupling conditions, and the simulation results are comprehensively analyzed. The results show that SFSLCD has good seakeeping performance. The kinematic response in normal sea states is moderate, which is the operating condition for litter collection. The kinematic response in rough sea states is relatively large, but the mooring cables meet the strength requirements to ensure the safety of SFSLCD.
