Modelling the aeroelastic response of slender structures to vortex-induced vibrations: Industry transfer through full-scale experimental campaign at a wind turbine

在本项目中，在风力机上进行了风、力和结构响应的现场测试，并将根据上述建议开发的气动弹性模型转换为自然比例尺。在细长结构的涡激过程中，锁定区发生了气动弹性干扰。在研究中，它被建模为负气动弹性阻尼。这种方法已经被前面的建议所采用，并在一个基本的涡激模式中得到了实现。建模的同时还进行了风洞实验。通过实验验证，可以消除最大振动幅值模拟中的理论缺陷，并且可以比以前更加真实和透明地预测对与设计相关的疲劳过程起决定性作用的应力振荡。在该转让项目中，计划对155米高的SG14风力涡轮机原型进行现场测量，作为与应用合作伙伴西门子Gamesa可再生能源合作的一部分。样机位于丹麦的ästerild风力涡轮机试验场。将测量以下参数：1)使用气象桅杆测量风速分布和风向；2)风力机塔架上的风压，两层之间各有15°角间距，由此可以积分风力；3)沿高度的加速度；4)塔壁的应变，以确定底部和轮毂高度的弯矩。这项研究的目的是将前一个项目中发展的涡激振动气动弹性模型的概念转化为跨临界雷诺数、结构的多个特征振型和真实的湍流入流剖面的现实。因此，可靠地确定结构的模态参数(固有频率、固有振型和阻尼比)是共同决定的，以便能够在使用所开发的气动弹性模型时真实地预测涡激振动。在响应测量的基础上，借助工作模式分析，确定了系统辨识逆问题的解。此外，该项目基础上的显著特点是通过深入调查通过同时测量塔表面压力而获得的风力来补充结构响应的特征。因此，这些研究使我们能够为烟囱、塔楼、桅杆和其他对涡激振动敏感的细长结构的响应计算制定一个行业标准的概念。

In this project, wind, force and structural response measurements are carried out in field tests on a wind turbine and the developed aeroelastic model according to the preceding proposal is transferred to the natural scale. During vortex excitation of slender structures, an aeroelastic interaction occurs in the lock-in region. In research, it is modelled as negative aeroelastic damping. This approach has been taken up by preceding proposal and implemented in a fundamental vortex excitation model. The modelling has been accompanied by wind tunnel experiments. Through experimental verification, theoretical deficits in the modelling of the maximum oscillation amplitude can be eliminated and the stress oscillations that are decisive for the design-relevant fatigue processes can be predicted much more realistically and transparently than was previously possible. In this transfer project, it is planned to carry out field measurements on the prototype of the 155 m high wind turbine SG14 as part of the cooperation with the application partner Siemens Gamesa Renewable Energy. The prototype is located at the Østerild wind turbine test field in Denmark. The following quantities will be measured: 1) wind speed profile and wind direction using a meteorological mast, 2) wind pressures at the tower of the wind turbine with 15° angular spacing at each of the two levels, from which wind forces can be integrated, 3) accelerations along the height and 4) strains of the tower wall to determine bending moments at the base and at hub height. The research aims at transferring the concept of aeroelastic modelling in vortex-induced vibrations developed in the preceding project to the reality of transcritical Reynolds numbers, multiple eigenmodes of the structure and realistic turbulent inflow profiles. The reliable determination of the modal parameters (natural frequencies, natural modes and damping ratios) of the structure is thereby co-decisive in order to be able to realistically predict the vortex-induced vibrations when using the developed aeroelastic model. The solution of the inverse problem of system identification is determined on the basis of the response measurements and with the help of Operational Modal Analysis. Furthermore, the distinguished feature at the base of this project is to complement the characterisation of the structural response by an in-depth investigation of the wind forces obtained from simultaneous pressure measurements on the tower surface. As a result, the investigations enable the development of a concept for an industry standard for the response calculation of chimneys, towers, masts and other slender structures that are sensitive to vortex-induced vibrations.