Design of a Novel Experimental Facility for Testing of Tidal Arrays

Abstract

Abstract:In order to obtain the maximum amount of energy from tidal stream extraction devices, deployment in large arrays should be studied. The area of seabed with favorable conditions is fairly limited; therefore layout spacing has to be optimized. In this paper a feasibility study for a novel experimental facility, suitable for the testing of an array of tidal devices, is presented. To avoid space and scale limitations of towing tanks, testing is proposed to be performed in large lakes or calm seas using a self-propelled vessel, which will carry an array of devices with variable spacing, creating relevant speed differences and measuring their performance and loading. Using hydrodynamic scaling laws, an appropriate size for test turbines and the range of vessel speed was determined to fulfill experimental requirements. Computational fluid dynamic simulations, using the actuator disc method, have suggested a suitable turbine array configuration to resemble real application conditions. A simplified model of the vessel was analyzed using the finite elements method to determine the main scantlings. The hull resistance calculated by empirical formulae was found to be negligible compared to the resistance of the tested turbine. It was confirmed that turbine size and speed determined by scaling laws are also reasonable from a propulsion point of view.

Finite Element Analysis of Tidal Turbine Blade Subjected to Impact Loads from Sea Animals

“…These configurations of turbines have shown to affect significantly the hydrodynamic characteristics, development and interaction of the wake field of tidal current turbines within the array [12][13][14]. Pintar and Kolios [15] presented an experimental facility, accounting for a vessel with its own propulsion, carrying arrays of horizontal axis tidal turbines. The interaction of the turbines was investigated using computational fluid dynamics (CFD), considering different configurations of the turbines, while a numerical model was also developed simulating the structural response of the testing facility.…”

Developing a coupled turbine thrust methodology for floating tidal stream concepts: Verification under prescribed motion

“…High-fidelity numerical methods, such as CFD, have been used extensively in mature industries, like wind energy, to assess the behaviour and performance of horizontal axis turbines. The development of tidal stream turbines has benefited greatly from the knowledge gained in the wind industry, however; it is important to recognise that tidal turbines can be subject to free-surface effects (such as ventilation), possible cavitation and bi-directional flow and that the established methods must be adapted to provide an accurate prediction of tidal stream turbine behaviour [35]. Moreover, existing methods rarely take into account the arbitrary motion of a freely moving turbine which, in the case of a floating tidal stream device, could result in a turbine velocity comparable to the free-stream velocity of the fluid.…”

Fluid-Structure Interaction of Wind Turbine Blade Using Four Different Materials: Numerical Investigation

“…Evaluation of Von-Mises stress and deformation are also done. The developed FSI model can also be used for vertical axis wind turbine [23] and tidal turbine [24]. The paper is formulated as follows.…”