To harvest acoustic energy from urban railways, a novel and practical acoustic energy harvester is developed. The harvester consists of a piezoelectric circular plate and a Helmholtz resonator. Based on the field test data of urban railways, the resonance frequencies of the piezoelectric circular plate and the Helmholtz resonator are near 800 Hz. The Helmholtz resonator is designed to amplify the sound pressure. Thus, a lumped parameter model is established. The piezoelectric circular plate is used to convert mechanical energy into electrical energy. The simulation results show that the output power of the harvester is approximately 25 μW and the maximum voltage is 0.149 V under the excitation of urban railway noise. The experiment device is also developed. The maximum output power of the harvester is 8.452 μW, and the maximum voltage is 0.082 V. The experimental and the numerical results are in good agreement and demonstrate the effectiveness of the proposed acoustic energy harvester.

中文翻译：

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一种新型城市铁路噪声圆板声能收集器

为采集城轨声能，研制了一种新颖实用的声能采集器。采集器由压电圆板和亥姆霍兹谐振器组成。根据城轨现场试验数据，压电圆板和亥姆霍兹谐振器的谐振频率接近800Hz。亥姆霍兹谐振器旨在放大声压。从而建立了集总参数模型。压电圆板用于将机械能转化为电能。仿真结果表明，在城轨噪声激励下，采集器的输出功率约为25  μ W，最大电压为0.149 V。还研制了实验装置。收割机最大输出功率为8.452 μ W，最大电压为 0.082 V。实验和数值结果吻合良好，证明了所提出的声能采集器的有效性。