无叶片风力机异型表面捕能装置涡激振动响应机理及优化研究

For the problem of capturing wind energy from vortex-induced vibration and the demand of distributed wind power generation, this project will propose a non-blade wind turbine based on vortex-induced vibration, and the response mechanism and optimization of vortex-induced vibration will be carried out for trapping energy device with different surface shape. By analyzing the model and algorithm of predicting standard cylinder vortex-induced vibration response, the modified wake oscillator model and decoupling algorithm applied to trapping energy device is presented according to the structure characteristics of its special-shaped surface，and the vibration response mechanism of trapping device is discussed. The tail-vortex mode and wake flow field of trapping device with different surface shapes are discussed by combined with the three-dimension analysis model and visualization technology, and the factors that affect the increase of frequency locking range and the mutual interference mechanism between these factors are studied. The fluid-solid coupling multi-objective optimization model of trapping device is built. Combined with the collaborative optimization algorithm, the influence of structure and its shape parameters, Reynolds number, damping ratio on its response form and the frequency locking range is discussed in order to improve the capturing energy efficiency of trapping device. The multi-cases dynamic response topology optimization model of attached damping layer material on the substrate of trapping device is built, and the influence of layout types of damping layer on modal parameters of trapping device is discussed, and the natural frequency of trapping device varies with the different wind field. Finally, the models and algorithms presented in research will be modified and improved according to the experiment test results. The results obtained will provide theoretical guidance for the structural design of non-blade wind turbine.

针对从涡激振动中捕获风能的问题以及分布式风力发电的需要，本项目提出一种基于涡激振动的无叶片风力机，并对其具有异型表面形状的捕能装置开展涡激振动响应机理及优化研究。通过分析预测标准圆柱体涡激振动响应的模型及算法，根据捕能装置异型表面的结构特征，寻求预测其涡激振动响应的改进型尾迹振子模型及解耦算法，并对其振动响应机理进行研究；结合三维分析模型和可视化技术，探讨不同表面形状捕能装置的尾涡模式和尾迹流场,研究影响锁频范围增大的因素及相互干扰机理；研究并建立捕能装置流固耦合多目标形状优化模型，结合协同优化算法，探讨结构及形状参数、雷诺数、阻尼比等对其响应形式和增大锁频范围的影响，以提高其捕能效率；建立捕能装置基体敷设阻尼层的多工况动力响应拓扑优化模型，探讨敷设形式对其模态参数的影响，使捕能装置的固有频率随风场差异而变化；最后对所建模型及算法进行实验验证。所得结果将为无叶片风力机的设计提供理论指导。

为满足分布式风能发电的需要，本项目提出了一种基于风致涡激振动的无叶片风力机并对其涡激振动机理开展研究。将无叶片风力机捕能系统简化一个质量—弹簧—阻尼振动系统，推导了捕能系统的固有频率及其捕能效率计算式，基于控制变量法探讨了系统阻尼比、质量比和固有频率对捕能柱涡激横向摆动特性的影响，降低质量比有利于提高捕获效率和增大锁频区间；得到了单、双圆锥柱体的尾涡形态与振动轨迹及与间距比、斜列角相关的尾涡形态的变化规律，随剪切率的增大，圆锥柱体的振动轨迹由斜“8”字形变为“X”字形和“1”字形；研究了有限长捕能柱自由端效应对时均阻力系数、升力系数和St数的影响；提出了采用添加配重块方式来扩宽无叶片风力机锁频区间的方法及相应的装置，推导了配重块沿捕能柱上下移动时捕能系统的固有频率计算式，得到了配重块质量占比与扩宽锁频区间之间为二次函数关系；将桅杆结构引入到捕能柱系统，推导了与捕能系统几何形状相关的无量纲结构系数计算式，桅杆结构的引入有利于提高风能的捕获效率，但对于给定的捕能柱结构存在一个最佳的桅杆长径比；建立了无叶片风力机气动噪声的仿真模型，捕能柱涡激摆动产生的噪声为低频噪声，且噪声大小与其摆动角度和频率有关，当来流风速处于锁频风速区间时所产生的噪声最大；建立了基于EFG法各向异性材料薄板结构拓扑优化模型及其求解的GPU加速并行算法，以及薄板结构模态分析和动力响应分析的GPU加速并行算法，得到了材料性能与铺设角度对各向异性薄板结构拓扑优化结果的影响规律，以及复合材料的不同铺层层数、铺层顺序与角度对捕能柱壳体静刚度的影响，在风速一定时，阐明了捕能柱异型（双曲线形、抛物线形、圆锥形）表面综合刚度的差异性；研制了3种不同类型的无叶片风力机的发电机装置，以及对应的监测与控制装置、实验测试装置与自动润滑装置。上述研究成果对于提高无叶片风力机的捕能效率、捕能柱壳体结构的轻量化和工程应用具有重要的理论参考价值和指导作用。