为了研究不同石墨烯发声器结构对热声效率的影响, 建立了石墨烯发声器的声压解析模型, 对单层石墨烯发声器、多层石墨烯发声器以及镍铬基的泡沫石墨烯发声器的发声效率进行了理论与实验研究。首先, 介绍了石墨烯发声器的工作原理, 建立了石墨烯发声器的周期性温度变化模型和声压解析模型。然后, 实验研究了单层石墨烯发声器、多层石墨烯发声器以及镍铬基的泡沫石墨烯发声器的热声效率。实验结果表明: 在14~25 kHz内, 施加6 V交流电, 测距为6 cm的条件下, 单层、多层和泡沫石墨烯发声器的最高SPL分别为35.19, 20.36和33.42 dB, SPL理论值最高约为37.45 dB。具有较低电阻, 较低比热容, 较高导热率的石墨烯发声器可以获得较高的热声效率和声压。

To study the influence of different graphene sound-generator structures on thermoacoustic efficiency, a sound pressure analytical model was established. Theoretical and experimental studies were conducted on the thermoacoustic efficiency of a monolayer graphene sound-generator, multilayer graphene sound-generator, and nickel/chromium-based graphene foam sound-generator. Firstly, the principle of a graphene sound-generator was introduced. A periodic temperature change model and a sound pressure analytical model of this generator were then established. Finally, the three aforementioned sound-generators were studied using an experimental method. The experimental results show that the maximum SPL values of the monolayer, multilayer, and the graphene foam sound-generator are 35.19, 20.36 and 33.42 dB, respectively, in the frequency range of 14~25 kHz when 6 V AC is applied for a distance of 6 cm. The maximum theoretical SPL is approximately 37.45 dB. Graphene sound-generators with lower resistance, lower specific heat capacity, and higher thermal conductivity can achieve higher thermoacoustic efficiency and sound pressure.