基于流激振荡现象的流体动能收集技术研究

Research on Fluid Kinetic Energy Harvesting Technology Based on Flow-Induced Oscillation

针对偏远地区及特殊场景下的低功耗无线传感节点电源维护不易的问题,该文对一种基于流激振荡现象的流体动能收集技术进行了研究,结合压电技术可实现流体动能转换至电能的过程。通过对流激振荡现象进行数值模拟及实验研究,分析了空腔结构中的流场及声场分布特性,探究了流体速度对声振荡频率及幅值的影响规律。利用COMSOL软件对声电转换过程进行仿真,实现了完整的流体动能-电能的转换过程。研究结果表明,在一定的速度条件下存在频率稳定的声振荡区间,可驱动压电换能装置输出频率稳定的电压,当气体流速为30.5 m/s时(相当于高压输气管道的流速范围),声场压力振幅可达6.12 kPa,对应的输出开路电压为2.62 V。当外接15 kΩ电阻时,最高输出功率可达0.29 mW。

In order to address the problem that it is difficult to maintain the power supply of low-power wireless sensor nodes in remote areas and special scenarios,this work investigates a fluid kinetic energy harvesting technology based on flow-induced oscillation phenomenon,which can realize the conversion process from fluid kinetic energy to electric energy by combining with piezoelectric technology.Through numerical simulation and experimental research on the phenomenon of flow-induced oscillation,the flow field and sound field distribution characteristics in the cavity structure are analyzed,and the influence of fluid velocity on the frequency and amplitude of acoustic oscillation is explored.The acoustic-electric conversion process is simulated by COMSOL software,and the complete conversion process of fluid kinetic energy to electric energy is realized.The research results show that there exists an acoustic oscillation range with stable frequency under certain speed conditions,which can drive the piezoelectric transducer to output a voltage with stable frequency.When the gas flow rate is 30.5 m/s(equivalent to the flow rate range of high-pressure gas transmission pipeline),the amplitude of the sound field pressure can reach 6.12 kPa,corresponding to an output open circuit voltage of 2.62 V.When an external 15 kΩresistor is connected,the maximum output power is up to 0.29 mW.