Hydrodynamic Research And Structural Optimization Of A Multi-pendulum Wave Energy Converter

Wave energy is the kinetic and potential energy resulting from the motion of ocean waves.As one of the most abundant energy in ocean resources, it has caused broad attentions around theworld. Pendulum wave energy converter becomes more popular than others, for the simple andreliable structure, high capture efficiency, and wide scope of application. The present paperrelates to the multi-pendulum wave energy converter apparatus, together with hydrodynamicresearch and structural optimization.1. On the background of China’s energy structure and vast ocean wave energy, the presentpaper describes the research significance and analyzes the overseas and domestic research statusof pendulum wave energy converter from theoretical analysis, model test and prototype testunder sea conditions.2. Based on the three-dimensional potential flow theory and hydrodynamic research, thehydrodynamic coefficients and equations of motion response of multi-pendulum are therebyconcluded in frequency domain and time domain.3. The software AQWA is used to calculate the frequency domain and time domain ofdouble and three pendulums in the aspect of hydrodynamic. Compared with the single pendulumsystem, the result shows that the interactions of multi-pendulum will cause different resonancepeak from single pendulum. Meanwhile the spacing between the pendulums are changed andcalculated many times so as to get the very parameters for energy converter apparatus. Thosecalculations demonstrate that the highest capture efficiency will be realized just when thespacing between pendulum are just close to the half incident wavelength. In the case of threependulums, the motion response of the middle one is higher than the other two.4. According to some model design criterions, a model of multi-pendulum wave energyconverter is designed and tested in wave tank, so is the single pendulum system. Then theanalysis of numerical results and capture efficiency are compared to prove the validity ofnumerical simulation.5. On the basis of result of numerical simulation, the objective function and the constraintconditions of the multi-pendulum’s structure are built and optimized by genetic algorithm. The structure parameters are finally concluded. The result shows that the ideal parameters can beacquired by the method of GA optimizing the structure.6. Referring to the nearshore sea conditions of Fujian, this paper analyzes comprehensivelythe three install locations which are above the sea, in the sea and under the sea. The best one isfinally selected by the means of AHP.