基于椭圆正弦攻角运动振动翼的能量采集性能分析

Energy harvesting performance of an oscillatory foil with elliptic sine attack angle

振动翼作为一种有效的潮流能、风能换能装置,可将潮流或风的动能转化为机械动能推动电机发电。该文通过调整机翼的周期性垂向运动与旋转运动实现机翼与来流的有效攻角控制,来流对机翼的流体动升力可推动机械装置往复运动并转换为电机的转动。假定机翼表面的边界层极薄,黏性仅在边界层内部作用,泻出涡仅从机翼的尾缘处泻出,引入势流理论,采用边界元法与泻出涡模型模拟机翼边界层的外部流场。主要分析了机翼以椭圆正弦为有效攻角运动的振动运动的能量采集性能,计算NACA0012机翼在不同运动频率、振动幅值与有效攻角时的能量采集效率,并分析了椭圆正弦K参数对能量采集的影响,研究实现高效率能量采集的机理。

Oscillatory foil is an effective energy harvesting device to extract energy from incoming flow, including current and wind. By adjusting the periodical vertical and rotational motion, the effective attack angle can be controlled;and the fluid loads can be utilized to drive the reciprocating motion of mechanical device. Assuming that the boundary layer is thin and the viscosity only has effects within the layer, the velocity potential is introduced to simulate the outer fluid flow through boundary element method and vortex shedding scheme. The energy harvesting performance of NACA0012 foil in oscillatory motion, where the effective attack angle is elliptic sine function, is analyzed. The energy extraction efficiency at various heave amplitude, the effective attack angle and Strouhal number is calculated, the effects of K parameter on the energy efficiency have been analyzed;the mechanics to achieve high efficiency is investigated.