Theory of suspended carbon nanotube thinfilm as a thermal-acoustic source

Solution for acoustic field of thermo-acoustic emission from arbitrary source

“…As to the current hot topic -nanothermophones, [19][20][21][22] the formulas for their acoustic fields, either near field or far field, can also be derived from the Eq. (11) just by taking the nanofilm as the sample and the gas as the backing material, as expressed in Eq.…”

“…[2][3][4][5][6][7][8][9][10][11][12][13] However, theoretical investigation of TA emission seriously lags behind the experimental one due to comparatively fewer efforts. Currently, alomast all the formulas for calculating TA emission so far are one-dimensional, 1,[14][15][16][17]19,22 taking advantage of the plane-wave solution based on the pressure-temperature coupled equations in a fluid given by F. A. McDonald and G. C. Wetsel, Jr., 18 and the problems of near-and far-field TA emission need to be dealt with seperately. The multi-dimensional TA emission problems, e.g.…”

Gap separation effect on thermoacoustic wave generation by heated suspended CNT nano-thinfilm

“…Another magnificent feature of a thermoacoustic device is that it is able to introduce a wideband response effectively for a wide range of frequency and thus the design of a sound speaker can be tremendously simplified [4]. The sound pressure generated by a thermoacoustic device greatly depends on the heat capacity per unit area (HCPUA) of the conductor [5,6]. In the last many decades, materials with a small HCPUA were unavailable and, as a result, the development of thermoacoustic device remained stagnant for a long time.…”

“…Xiao et al [5] improved the piston model proposed by Arnold and Crandall [1] to explain their experiment result and it was first claimed that the conductor HCPUA was the key factor to upgrade practical applications of any thermoacoustic devices. However, this model is only suitable for predicting far-field thermoacoustic responses [6]. Using Green's function, Vesterinen et al [13] investigated thermoacoustic efficiency and the effect of a heatabsorbing substrate on the emitted sound pressure.…”

“…However, the influence of thermal loss and conductor HCPUA was not included in their analysis [13]. Recently, Lim et al [6] and Tong et al [22] reported accurate analytical solutions for thermoacoustic radiation from a suspended (CNT) thinfilm and a gas-filled encapsulated thermoacoustic transducer, respectively. Their analytical solutions were compared with published experimental measurements and excellent agreements were achieved.…”