Study On Wave Slamming Characteristics Of The Buoy Of Wave Energy Converters

Wave slamming phenomena happen commonly during the operation of all marine engineering structures.It's necessary to take the problem of wave slamming into consideration in the process of strength design of marine structures such as ships.The oscillating-buoy wave energy converter captures wave energy through the buoy and is also impacted by the slamming of waves.The load generated by the wave slamming may cause damage to the wave energy converters.Considering the wave slamming phenomenon is particularly important for the design of the wave energy converter,especially the oscillating buoy.This study provides a reference for the design and further calculation method of wave slamming load of oscillating buoys,which has engineering application value and theoretical significance for reducing the wave slamming load,reducing structural damage and prolonging the working life of oscillating buoys.In this paper,the numerical simulation method based on the CFD software FLUENT is verified.Using the geometric model consistent with the literature,the experimental results of the slamming pressure peak value and velocity attenuation of the cone free entry in the pool in the literature are compared with the results calculated by the numerical method.It is proved that CFD method can give an accurate prediction of the slamming pressure and other information,and verify the effectiveness of water entry slamming numerical model.Then,the slamming characteristics of buoys with different shapes are studied by numerical simulation.The influence of the shapes of buoys and the deadrise angles on the peak acceleration and the peak slamming pressure is discussed.The rise of free surface and the change of physical quantities in the flow field such as pressure and velocity are analyzed.The temporal and spatial distribution characteristics of slamming load are studied.According to the calculation results,the influence rules of different shape parameters of the oscillating buoy in the slamming process are obtained by comparative analysis,and the change rules of flow field are summarized,which can provide a reference for the design of the oscillating buoy.On the basis of numerical simulation,this paper takes the oscillating buoy model with truncated cone shape as the test object,and carries out slamming tests under different wave parameters.By arranging pressure sensors at different heights on the wave side of the oscillating buoy model,the slamming pressure characteristics of bottom slamming,side slapping and overtopping slamming on the oscillating buoy and their variation with wave parameters are studied.Finally,the numerical simulation model of the dynamic response of the oscillating buoy under the wave slamming load is established.By establishing the same three-dimensional oscillating buoy model and selecting the same wave conditions,the structural dynamic response of the oscillating buoy and the physical quantities and shape changes of the flow field are simulated,and the structural response characteristics of the oscillating buoy are analyzed by comparing with the experimental results.