基于涡致振动的内置压电悬臂梁柔性圆管能量收集结构的数值模拟

Numerical Simulation of Energy Harvesting Structure of Flexible Circular Tube with Built-in Piezoelectric Cantilever Beam Based on Vortex Induced Vibration

为了分析基于涡致振动的内置双晶压电悬臂梁柔性圆管压电能量收集结构的运动机理和性能,对其进行了流固耦合和压电耦合数值模拟。对一端固定一端自由的柔性圆管进行了流固耦合数值模拟,在流速为1.1 m/s,柔性圆管直径D为0.03 m,高度为0.11 m时,该结构的涡致振动能够处于稳定的锁频状态。对折合速度为1.3~4.0,中心距为3 D^6D的前置等径刚性圆柱阻流体的柔性圆管进行了流固耦合和压电耦合的数值模拟。研究结果表明,柔性圆管的振幅响应和压电悬臂梁的开路输出电压均随折合速度的增大而增大,在仿真参数范围内,结构的振幅响应和输出电压时程曲线均为稳定的周期函数。当折合流速为4.0,中心距为5 D时,结构产生的振幅最大,为2.38×10-3 m,电压为6.75 V。证明了根据不同流速,可以通过调节圆管的结构参数以使涡致振动产生锁频现象,从而得到最大振幅和输出电压,进而可将其用于电能收集,为下一步能量收集结构的实验制备提供了理论参考。

To understand the mechanism and performance of a flexible circular tube piezoelectric energy harvesting structure with built-in bimorph piezoelectric cantilever beam based on vortex-induced vibration,a fluid-structure coupling and piezoelectric coupling numerical simulation were conducted.First,the fluid-structure coupling numerical simulation of the flexible circular tube with one fixed end and another free end was performed.Results show that at the velocity 1.1 m/s,the diameter of the flexible circular tube was 0.03 m and the height was 0.11 m,the vortex-induced vibration of the structure could be in a stable resonance state.Second,the simulation was done in the reduced velocity of 1.3~4.0 and the center distance of 3 D^6D.Results show that the response amplitude of flexible circular tube and the open circuit output voltage of piezoelectric cantilever beam increased with the velocity decrease,and both the time-history curve of response amplitude and output voltage were in stable periodic functions within the range of simulation parameters.Third,at the velocity of 4.0 and the center distance of 5D,the amplitude generated by the structure reached the peak value of 2.38×10-3 m,and the voltage was 6.75 V.Therefore,the structure parameters of the circular tube could be adjusted to control resonance in vortex-induced vibration to obtain the maximum amplitude and output voltage.provide a theoretical reference for the experimental setup of energy harvesting structure in the future.