Optimization of a tuned liquid column damper subject to an arbitrary stochastic wind

Abstract

The current Brazilian energy scenario is undergoing impactful changes. There is a clear need to adjust the current energy sector that presents an imbalance due to the almost exclusively dependency on hydroelectric power. This brings the need of diversifying the Brazilian energy matrix, including other energy sources that are both efficient and renewable. Amongst the available options, the wind energy stands out. Remarkable progress in wind turbine technology has been made over the past years, allowing the design of higher and slender structures for increasing efficiency in energy production. Parameter optimization for tuned liquid column dampers (TLCD), a class of passive structural control, has been previously proposed in the literature for reducing vibration in wind turbines and several other applications. However, most of the available work considers the wind excitation as either a deterministic harmonic load or random load with white noise spectra, which might not be representative of the actual wind load. This paper proposes an optimization approach for the TLCD parameters subjected to an arbitrary wind spectrum, given that its power spectral density is know. Finally, a numerical example is given in which a simplified wind turbine model is loaded by different stochastic wind profiles. Satisfactory reduction in the response vibration levels is found, and it is shown that different wind profiles can significantly affect the optimization results, i.e. the best TLCD parameters are dependent on the wind model.