超高频热声制冷机谐振腔内声场分析

Acoustic field analysis in resonant cavity of ultra-high frequency thermoacoustic refrigerator

基于超高频范围内辐射板活塞振动的近场特性,从理论上分析了超微型热声制冷机谐振腔内声压在辐射板活塞振动近场的分布规律。并且应用有限元声学分析软件ATILA对热声制冷机谐振腔内声场分布进行数值模拟。由理论和仿真可知,在超高频率范围内辐射板活塞振动近场内的声压幅值出现“明区”和“暗区”交替分布声压,呈现活塞振型,有效的抑制了超高频情况下高次谐波的产生,保持了声波的单色性,有利于热声效应的产生。

Based on the near-field characteristics of the vibration of the piston plate in the ultra-high frequency range,the distribution of the sound pressure in the resonant cavity of the radiation plate in the near-field vibration of the ultrasonic miniature thermoacoustic refrigerator was theoretically analyzed. The finite element analysis software ATILA was used to simulate the acoustic field distribution in the cavity. Based on the theory and simulation,it is found that in the ultra-high frequency range,the sound pressure amplitude near the field of radial plate piston vibration appears to be alternately distributed in "bright area" and "dark area",presenting the piston vibration mode.It can effectively suppress the generation of high order harmonics under the condition of ultra-high frequency and maintain the monochromatism of sound wave,which is beneficial to the generation of thermoacoustic effect.