梯形摆式波能转换装置水动力性能研究

HYDRODYNAMIC PERFORMANCE OF TRAPEZOIDAL PENDULUM WAVE ENERGY CONVERTER

基于势流理论,采用频域方法对固定梯形摆式波能转换装置的水动力性能进行研究。由于摆式波能转换装置固有周期较长,在固有周期附近辐射阻尼系数较小,故波能转换效率并不高。在线性理论下研究波能转换装置的水动力性能时通常忽略非线性阻尼的作用,当波浪周期等于装置的固有周期且负载阻尼系数等于辐射阻尼系数时可获最大的输出功率。类似于船舶横摇,对摆式波能转换装置而言有必要考虑非线性阻尼的影响,分析非线性阻尼对最佳负载阻尼系数的影响及负载阻尼系数对摇幅及波能转换效率的影响。

Based on the potential theory, hydrodynamic performance of trapezoidal pendulum wave energy converter was studied by applying the frequency domain method. It is shown that the natural period for a fixed pendulum wave energy converter is relatively long. And the wave energy conversion efficiency is smaller because the radiation damping near the natural period is very small. In linear theory, the nonlinear drag damping is often neglected during studying wave energy converters, the maximum wave energy conversion efficiency is achieved when the natural period of the converter is equal to the wave period and the power take-off damping is equal to radiation damping. As a ship rolling motion, for trapezoidal pendulum wave energy converter, the nonlinear drag damping must be taken into account, so the effect of the nonlinear drag damping on the optimum power take-off damping has to be analyzed. The influence of power take-off damping on the motion amplitude and conversion efficiency are also analyzed.