Investigation On The Performance Of The Oscillating Buoy Wave Power Device

Scientists of many countries have investigated wave energy - a kind of clean, renewable energy, and have produced many kinds of wave-power devices, most of which have been applied in manufacture, for many years.The oscillating buoy wave power device (OD) investigated in this paper consists of a buoy placed in a port and some hydraulic or mechanical devices mounted on the coast. The buoy extracts wave energy and drives a generator through the hydraulic or mechanical devices to generate electricity. The advantages of this device are that it is cheaper and highly efficient; on the other hand, its stability is not good. So this device is attractive to some countries where the density of wave energy is low. For example, it is advisable to adopt this device in China.To investigate the performances of OD, the objectives of this thesis are as follows:(1) Based on the linear potential theory, the three-dimensional hydrodynamic analysis was conducted using the Boundary Element Method to study the performance of the shore-mounted wave-power device with consideration of the effect of the complicated topography nearby the device, and the relationship of the maximum capture width ratio and the optimum damping has been gained; (2) The effects of the topography nearby the device and the main design parameters of the device on its performance were examined through 16 case studies. The computed results show that the harbor-like topography is of great importance to the efficiency of the device, and that every design parameter has a certain effect on the performance, so the parameters of the device might be optimized to improve its performance within a certain interval of wave period. Simultaneously, the curves of the maximum capture width ratio with the topographies or the main design parameters are demonstrated, respectively; (3) According to the seas of the south of China, several optimum results can be gained by parameter optimization, which is useful for designing wave-power stations; (4) The comparison of the performances of the original and improved devices has shown that the conversion efficiency, especially the reliability of the device has much been improved.In conclusion, the OD is a promising kind of wave power device.