A fast hydrodynamic prediction method of horizontal axis tidal turbine with surging motion under wave-current condition

Abstract

To obtain the hydrodynamic load characteristics of the floating horizontal-axis tidal turbine (HATT) with rotation and surging motion under wave-current conditions, a numerical method based on CFD is established to calculate and analyze the power and axial load characteristics of the HATT under different wave heights, surge periods, surge amplitudes and tip speed ratios. The results demonstrates that the power and axial load coefficients of the HATT fluctuate based on the relative wave and surge frequencies, and the fluctuation amplitude increases gradually with the increase of surge amplitude, surge frequency, and tip speed ratio. In this foundation, a fast prediction model of the power and axial load coefficients is proposed, and the correlation coefficients in the model can be obtained by fitting the CFD calculation results based on the least square method. The results show that the calculation results based on the fast prediction method are basically consistent with the CFD calculation results, verifying that the fast prediction method can effectively predict the hydrodynamic loads of the HATT with rotation and surging motion under wave-current conditions. Research findings can provide a fast calculation method of HATT axial load and power coefficients when the HATT and floating platform are coupled.