Wind turbines, though designed to harvest wind energy, are also subjected to complex aerodynamic loads during operation. Studying the fluid-structure coupling, especially dynamic instabilities, remains one of the most important structural engineering issues for the wind energy industry. With an exponential growth in wind energy production, it is critical to continue improving the safety and availability of wind turbines, while avoiding unnecessary conservatism in their design.
Passive vibration control techniques, such as Tuned Mass Dampers (TMDs), are extensively utilised for controlling wind-induced vibration (and the resulting cyclic stresses) in tall structures. Distributed TMDs are a promising candidate for the suppression of multi-modal and multi-directional wind excitation within the tight space constraints of the wind turbine structure. This PhD project will develop theoretical and computational models of wind turbines with distributed TMDs as the means for passive vibration control. Methods for the efficient prediction of wind turbine tower aeroelastic excitations will be developed.
The project will perform the fundamental task of quantifying second-order aerodynamic effects that are currently ignored in design codes, while also developing a predictive modelling technique that is computationally efficient. Aerodynamic loads resulting from blade rotation, crosswinds, and, vortex shedding, are not considered in most dynamic models of wind turbines. In this PhD project, these complex aerodynamic loads will be quantified (experimentally and numerically) and coupled with lumped-parameter and finite-element models of the turbine.
The research outcomes will provide wind engineers with practical tools to optimise the design parameters of passive vibration controllers, which will ultimately increase the availability of wind turbines over a wide range of weather conditions and maximise energy output and the lifetime of wind turbines. The knowledge advancements made in this project will also be applicable to other slender structures subjected to wind loading.