Aliev Ali E, Mayo Nathanael K, Baughman Ray H, Avirovik Dragan, Priya Shashank, Zarnetske Michael R, Blottman John B
Alan G. MacDiarmid NanoTech Institute, University of Texas at Dallas, Richardson, TX, 75083, USA.
Nanotechnology. 2014 Oct 10;25(40):405704. doi: 10.1088/0957-4484/25/40/405704. Epub 2014 Sep 12.
Carbon nanotube (CNT) aerogel sheets produce smooth-spectra sound over a wide frequency range (1-10(5) Hz) by means of thermoacoustic (TA) sound generation. Protective encapsulation of CNT sheets in inert gases between rigid vibrating plates provides resonant features for the TA sound projector and attractive performance at needed low frequencies. Energy conversion efficiencies in air of 2% and 10% underwater, which can be enhanced by further increasing the modulation temperature. Using a developed method for accurate temperature measurements for the thin aerogel CNT sheets, heat dissipation processes, failure mechanisms, and associated power densities are investigated for encapsulated multilayered CNT TA heaters and related to the thermal diffusivity distance when sheet layers are separated. Resulting thermal management methods for high applied power are discussed and deployed to construct efficient and tunable underwater sound projector for operation at relatively low frequencies, 10 Hz-10 kHz. The optimal design of these TA projectors for high-power SONAR arrays is discussed.
碳纳米管（CNT）气凝胶片通过热声（TA）发声在很宽的频率范围（1 - 10⁵赫兹）内产生平滑频谱的声音。将CNT片材在刚性振动板之间的惰性气体中进行保护性封装，为TA声音投影仪提供了共振特性，并在所需的低频下具有吸引人的性能。在空气中的能量转换效率为2%，在水下为10%，通过进一步提高调制温度可以提高该效率。使用一种为薄气凝胶CNT片材开发的精确温度测量方法，对封装的多层CNT TA加热器的散热过程、失效机制和相关功率密度进行了研究，并将其与片层分离时的热扩散距离相关联。讨论并应用了适用于高应用功率的热管理方法，以构建在相对低频（10赫兹 - 10千赫）下运行的高效且可调谐的水下声音投影仪。讨论了这些用于高功率声纳阵列的TA投影仪的优化设计。
