小型振动压电发电机气流致振发电技术

The object of study is a small vibratiing piezoelectric generator . For problems of self-power for complex electronic application system and uncontinuous power supply on piezoelectric generation, So the piezoelectric generating method will be put forward to collect the vibration from the environmental flow. Research on power generation technology will be developed in external airflow-induced vibration into electrical energy by small composite piezoelectric system. Theories of computational fluid dynamics（CFD） , computational aeroacoustics （CAA）and multi-physical coupling （MPC）are synthesized. A combination method of numerical simulation and experimental modal analysis is used. According to the principle of airflow-induced sound wave, acoustic-induced vibration, a self-modulating mechanism of intraductal turbulence mechanical control will be seeked and finded. The coupling effect of dynamic airflow-sound wave - solid will be revealed in cavity of body. Using technologies of the mechanical frequency pumping, wide-bandwidth transducers，it is make a study of small multi-resonant piezoelectric transducer technology and optimization method of power management circuit. It is put up the integrated structure of miniature passive vibration and piezoelectric transducer and the compositive interface circuit of Synchronous acquisition and electric energy storage. They have Low noise, and a good electromagnetic compatibility. To meet self-power supply demand of micro power circuit for the complex system, it can continuous power supply. The miniature turbulence control structure vibrating and multi-resonant piezoelectric transduceing are the innovation in its driving and vibration-piezoelectric energy harvesting. This research will be promoted the use of airflow utilizated and controlled technology in piezoelectric power generation technology.

以小型振动压电发电机为研究对象。针对复杂电子应用系统自供电和压电系统不连续供电问题，提出从环境气流中收集振动的压电发电方法,开展利用小型复合压电系统将外部气流诱发结构振动转化成电能的发电技术研究。综合运用计算流体动力学、计算气动声学和多物理场耦合理论，使用数值模拟和实验模态分析相结合的方法，根据气流致声、声致振动原理，探索机械自调制内湍流控制机理，揭示腔内动态气声固耦合效应；采用机械频率泵浦和宽带换能方法，研究小型化多谐压电换能技术与能量管理电路优化方法；设计小型无源振动与压电换能一体化结构以及同步采集与储能集成接口电路，噪声小，电磁兼容性好，可产生连续电能以满足复杂系统微功耗电路自供电需求。内湍流控制结构振动和小型多谐压电换能是其驱动和振动能量收集方面的创新，可为开发利用环境气流的可再生清洁能源提供新途径，对促进气流控制技术在压电发电中的应用具有重要的理论价值和指导作用。

以小型振动电源为研究对象，采用仿真和实验结合方法，开展小型振动压电发电机气流致声激励机理研究。.通过分析确定了短的等截面环隙进气道，具有进气口流态转捩快、流场趋于均匀快、整流作用明显、气流速度均匀对称恢复能力强等特点。提出了气流致声、涡激振的激振方法，建立了基于N-S方程和SST k-湍流模型的气流致声激振仿真模型。将仿真得到的腔底压力与实验测得的声压曲线进行比较，验证仿真模型的合理性。结果表明，腔底压力呈周期稳定变化，能形成持续稳定的振源，证明了该气流致声激励机构的可行性。.设计了气流致声压振动电发电机实验样机的压电换能装置。建立了气流致声压电发电机等效模型，给出了最大机械能输出功率表达式；分析了压电振子的工作方式，确定了压电振子的激励方式、振动模式、固定方式以及其最佳工作振型。.提出了适用于气流致声压电发电机的脉冲激励式压电换能同步采集方法。仿真分析了同步电荷采集（SCE）电路、基于电感的并联同步开关电荷采集（P-SSHI）电路、基于电感的串联同步开关电荷采集（S-SSHI）电路等负载电阻对换能器输出电压和负载接收功率的影响，通过对比得出结果：外接SCE电路，可以提高压电换能器输出电压，负载接收功率恒定；外接S-SSHI电路，适用于低匹配负载情况；外接P-SSHI电路适合高匹配负载情况。.对小型气流致声振动压电发电机原理样机性能进行了测试，研究了实验样机的激振力特性以及发电性能。数据表明，激振力幅值随着入流速度的增大而增大，且呈线性关系，频率放大明显，最高输出功率达到 mW .研究成果可为开发利用环境气流的可再生清洁能源提供新途径，对促进气流控制技术在压电发电中的应用具有重要的理论价值和指导作用。