基于磁性液体的调谐液体阻尼方法及其在风电塔架减振中的应用研究

Due to its flexibility and tall scale, wind turbines would be influenced by violent vibrations like wind and earthquakes, which not only will reduce the efficiency, but also cause fatigue damage on tower materials and lead to major accidents. Tuned liquid dampers are often used to damp vibrations in tall and flexible structures, but the sloshing frequency of the dampers is not adjustable which will reduce its vibration damping effect. In this project, a new frequency tunable liquid damping method with magnetic liquid is proposed, and to be used for the vibration control of wind power tower. The viscosity and magnetization characteristics of magnetic liquid at high and low temperature are studied; the multi-physics finite element model is built and a damper model for damping energy dissipation is established; the influence of the damping property of the magnetic fluid damper affected by magnetic fluids, the external magnetic field, the physical parameters and the geometric parameters of the shell are investigated; the vibration law of wind power towers under wind load and seismic load is explored, and the damping effect of tuned liquid dampers using magnetic liquid for the wind power towers is studied; the design rules of the tuned magnetic fluid damper, laying the foundation for the theoretical modeling and engineering application in this field, are explored under the working condition. The purpose of this project is to study on the damping method and its application of magnetic liquid tuning liquid based on multi-physics coupling model, energy dissipation analysis and experimental data. The work of this project shows important academic value and has widespread application prospect under the background to develop a large scale deployment of clean energy and wind power towers in China.

风电塔架作为高耸柔性结构，风和地震等引起风电塔架的强烈振动，不仅影响其发电效率，甚至引起塔架疲劳损伤引发事故。目前调谐液体阻尼器是高耸结构中常用的阻尼方式，但存在着调谐液体阻尼器频率不可调降低减振效果等问题。本项目提出以磁性液体为介质的调谐液体阻尼方法并用于风电塔架的振动控制。主要内容包括：研究高低温下磁性液体的磁化特性和粘度特性；建立包含磁场-流场-力场的多场耦合有限元模型和阻尼器的阻尼耗能模型，探究阻尼器各参数对磁性液体阻尼器阻尼性能的影响规律；探究风荷载和地震荷载作用下的风电塔架振动规律，调谐磁性液体阻尼器对风电塔架的阻尼效果；探索风电塔架工作环境下调谐磁性液体阻尼器的设计规则，为理论建模和工程应用奠定基础。本项目从多场耦合建模、能量耗散分析、实验研究等角度，研究磁性液体调谐液体阻尼方法及其应用，在我国大力发展清洁能源、风电塔架大规模部署的背景下，具有重要的学术价值和应用前景。

针对传统被动式调谐式阻尼器固有频率不可调的问题，结合磁性液体的磁-粘特性，本项目提出一种半主动调谐式磁性液体滚球阻尼器，实现了电流调节固有频率的功能。本项目主要研究内容包括（1）探究磁性液体磁化强度的温度特性，引入磁化强度的温度敏感度来表征磁化强度随温度的变化率，实验研究了磁性液体磁化强度的温度敏感度，定量分析了温度敏感度与激励磁场之间的关系； （2）设计两种不同结构的阻尼器，分别建立阻尼器外施电流与固有频率关系的数学模型，开展自由衰减、简谐激励和随机荷载振动实验验证调谐式磁性液体阻尼器的调谐减振能力，对比分析磁性液体种类对阻尼器减振性能的影响；（3）以调谐式磁性液体滚球阻尼器为研究对象，构建了包含粘性耗能和摩擦耗能的能量耗散模型，分析剪切力-位移滞回曲线，并计算阻尼器的能量耗散百分比，并与被动式调谐液体阻尼器进行对比，凸显磁性液体作为磁调控材料在阻尼器应用中的调谐优势；（4）构建风荷载和地震荷载作用下阻尼器的传递函数，推导阻尼器的最优调谐比和最佳阻尼比，确立阻尼器的最优尺寸参数；（5）比较不同控制算法在时变激励下阻尼器的频率跟随情况，确立自调谐控制算法，提高阻尼器在时变激励下的调谐减振性能。综合上述结果，本项目推动了对磁性液体磁学特性的研究和工程应用的发展，具有重要的理论和应用价值。.在本项目的资助下共发表SCI和EI收录论文6篇，中文核心收录3篇，获得发明专利1项，实用新型专利2项，培养博士研究生2名，硕士研究生5名。参加了8次学术会议和学术交流。