The variation of loads caused by the unsteady nature of tidal streams can have severe impacts on the turbine components. Val et al. (2014)1 studied the reliability of rotors and suggested that the dynamic loadings of tidal flows can generate an offset on one or more blade pitch settings. These changes will represent a loss of power capture and perhaps even premature failure of the components if not detected in time. The aim of this paper is to simulate the effects of a blade offset using 3D CFD and Blade Element Momentum Theory (BEMT) techniques. The results of the BEMT and CFD simulations are thus compared to the experimental data to assess the validity of using both numerical tools. From initial results, it is observed that the BEMT model provides a reasonable prediction at peak values of CP, with a slight reduction in performance coefficient for the offset blade case. However, initial comparative results from CFD show that the latter underestimates power coefficient values. Additional results will show the comparisons including larger values of blade offset cases and the results will also be analysed in terms of torque and thrust. 1D. V. Val, L. Chernin and D. V. Yurchenko, “Reliability analysis of rotor blades of tidal stream turbines,” Reliability Engineering and System Safety, vol. 121 , p. 26–33, 2014.
|Publication status||Published - 01 Sep 2017|
|Event||12th European Wave and Tidal Energy Conference - University College Cork, Cork, Ireland|
Duration: 27 Aug 2017 → 01 Sep 2017
|Conference||12th European Wave and Tidal Energy Conference|
|Period||27/08/2017 → 01/09/2017|