In the present work, a parameter study across a range of intrinsic wave periods, wave heights, current velocities, hub immersion depths, yaw misalignments and tip speed ratios on the dynamic behavior of blade root bending moments has been performed. For evaluating the dynamic loading, a modified unsteady Blade Element Momentum (BEM) model was prepared and coupled with linear and non-linear wave theories. Firstly, a validation study with previous experimental and numerical work was performed. Fifth-order model gave more realistic results taking in consideration the effects of current on wave properties. So, the parameter study calculations were performed using the fifth-order model. The effect of varying wave period, wave height and current velocity with and without the presence of yaw misalignment range on the response of root bending moments has been studied. In addition, the effects of tidal immersion depth variation at different flow conditions have been investigated. Also, the bending moments’ behavior due to the change of tip speed ratio has been studied.
|
