粘性流场中球面碳纳米管薄膜的热声发射

Thermoacoustic emission transducer is a novel device for acoustic emission. Thin-film acoustic transducer is traditionally driven by thin film oscillation due to electro-magnetic force. The principle is that the fluidic particles and the thin film share the same velocity on the solid-liquid interface. In other words, the displacement and velocity fields of fluidic particles are directly driven by thin-film vibration. However, the principle of thermo-acoustic emission is completely different. Thermo-acoustic emission is stimulated by controllable thermal field, which directly leads to the motion of fluidic particles. The fluidic expansion and contraction can be observed on the solid-liquid interface macroscopically. In this paper, a mathematical model for thermo-acoustic emission from carbon nanotube spherical films in viscous fluidic field is established, which improves the mathematical model for gaseous thermo-acoustics and expands the scope of thermo-acoustic application. In this paper，the external acoustic field from spherical carbon nanotube thin film is simultaneously calculated. The acoustic field is excited by sinusoidal harmonic thermal signal when inner sound absorbing medium exists. It is proved that the sound pressure level (SPL) of thermosacoustic emission can be flat in a wide frequency band. In addition, this paper further discusses a variety of factors affecting SPL for thermo-acoustic emission, which has certain reference value for thermo-acoustic emission in engineering.