波流环境中垂荡板水动力特性及其对浮式平台运动性能影响研究

The motion performance of floating offshore platforms, especially the heave motion performance, has been the research hotspot in offshore engineering around the world. As one of the effective devices in heave motion optimization, heave damping plates have been applied in improving the heave performance of SPAR and some new concepts of floating platforms. Research on the hydrodynamics of heave damping plates and their effects on motion responses of floating platforms in currents and waves is proposed and the main contents include: hydrodynamic characteristics of and the flow field around a heave damping plate in current conditions, interaction mechanisms between heave damping plates and free surfaces and waves; motion prediction of the platform with heave damping plates in wave and current conditions. CFD simulations, towing tests, forced oscillation tests and PIV measurements will be conducted to investigate the effects of current, oscillation amplitude and inclination angle of heave damping plates on the added mass, damping and current drag coefficients, to investigate the effects of immersion depth, oscillation amplitude and incident wave parameters on the hydrodynamics of heave damping plates near the free surfaces, to develop and validate the numerical model for predicting the motion responses of platform with heave damping plates. The present research will be helpful for not only enriching the knowledge of hydrodynamics of heave damping plates in waves and currents, but also providing theoretical basis and analysis method for engineering applications.

浮式海洋平台的运动性能特别是垂荡运动性能是国内外海洋工程领域的前沿研究热点。垂荡板作为平台垂荡运动性能优化的有效装置之一，已广泛应用于SPAR平台和一些新型浮式平台。本课题将针对垂荡板在波流环境中的水动力特性及其对浮式平台运动性能的影响开展深入研究，内容包括：水平流中垂荡板的水动力性能和周围流场形态，垂荡板与自由液面和波浪相互作用机理，波流联合作用下平台和垂荡板系统的运动响应预报。课题采用CFD数值模拟、水池拖曳和强迫振荡试验、PIV精细流场测量等研究手段，揭示水平流中垂荡板的附加质量、阻尼系数和流阻力系数随水平流速、垂荡振幅和垂荡板倾角的变化规律，阐明垂荡板浸没深度、振幅、入射波参数等对近自由液面的垂荡板的水动力特性影响规律，建立并通过试验验证垂荡板和平台系统运动响应精确预报数值模型。研究成果将显著提升关于波流环境中垂荡板水动力性能的认知，为垂荡板在浮式平台的应用提供理论基础和分析方法。

浮式海洋平台的运动性能特别是垂荡运动性能是国内外海洋工程领域的前沿研究热点。垂荡板作为平台垂荡运动性能优化的有效装置之一，已广泛应用于SPAR平台和一些新型浮式平台。垂荡板的水动力特性对深海平台的运动性能抑制具有重要影响。本课题以此为背景，针对平板结构和垂荡板在复杂环境中的流体动力特性和复杂尾流特性开展研究，内容包括：低雷诺数下圆盘尾流形态直接数值模拟、倾斜圆盘绕流数值模拟、高雷诺数下圆盘绕流大涡模拟、低雷诺数下振荡平板周围流场形态研究、垂荡板模型强迫振荡试验研究等5个主要部分。研究采用数值模拟和模型实验相结合的方法。数值模拟基于开源CFD程序OpenFOAM开展。研究深入探讨了低雷诺数下圆盘尾流的多种流动形态及其随着雷诺数的变化规律，发现了倾斜圆盘尾流的5种流动形态并对其临界雷诺数和倾角边界进行准确界定，揭示了高雷诺数下圆盘尾流的流动特性，首次发现振荡圆盘在低雷诺数下的5种不同的流动形态，基于实验的垂荡板模型强迫振荡实验获得了不同形状垂荡板的水动力参数。项目共发表论文13篇，其中，SCI论文11篇，两篇论文发表在Journal of Fluid Mechanics。研究工作对于揭示垂荡板的水动力特性具有重要意义，对垂荡板的设计和性能优化提供了理论基础。