Hydrodynamic performance and optimization of a pneumatic type spar buoy wave energy converter

In order to optimize the geometry of the spar buoy wave energy converter and improve its capture performance, numerical calculation and experimental research were carried out. The spar buoy oscillating water column wave energy technology can be regard as one of the pneumatic types oscillating single floating body. According to the study of the hydrodynamic characteristic and capture performance of the floater and the water column in the central pipe, the spar buoy mainly utilizes its heave motion to absorb wave energy. By comparing the numerical calculation results of the hydrodynamic performance and Capture Width Ratio (CWR) of five spar buoy models with different floater shapes, it is found that the flat-bottomed spar buoy has the best capture performance. The influence of the model's total mass on its capture performance was studied. The results show that an appropriate increase in the total mass increases the optimal response period and helps to improve the capture performance. The maximum CWR can reach 0.984. The research results show that the tail tube length has a minimal effect on the wave energy conversion characteristic, but the water column in the tube is greatly affected by its length.