圆柱形光声池结构及环境因素对声学本征频率的影响

以典型的圆柱形光声池为研究对象,建立光声池声学仿真有限元模型,并在此基础上,研究了光声池中谐振腔、缓冲腔、进出气孔结构参数以及温度、湿度因素对其声学本征频率的影响规律.研究结果表明:圆柱形光声池的进、出口孔对其声学本征频率影响极不敏感,设计计算中可以忽略不计,谐振腔的长度影响最为敏感,其次为谐振腔的直径.此外缓冲腔的长度与直径对其亦有一定影响,因而在准确计算时需要加以考虑.温度与湿度对光声池声学本征频率的影响均呈现正线性增长规律,温度的影响随着谐振腔长度的增大而减小,湿度的影响随着温度的升高而增大,仅计算光声池的声学本征频率时,湿度的影响在室温环境下且湿度变动较小的条件下可以忽略.

Influence of Cylindrical Photoacoustic Cell Structure and Environmental Factors on Acoustic Eigenfrequency

Taking the typical cylindrical photoacoustic cell as the research object,the accurate finite element model of photoacoustic cell acoustic simulation is established.On this basis,the structure parameters of resonant cavity,buffer cavity,intake and outlet holes,as well as temperature and humidity in the photoacoustic cell are studied.The influence of factors on its acoustic eigenfrequency is discussed.The results show that the inlet and outlet holes of a cylindrical photoacoustic cell are insensitive to its acoustic eigenfrequency,and can be neglected in design calculation.The length of the resonator is the most sensitive,followed by the diameter of the resonator.The simulation results also show that the length and diameter of the buffer chamber have a certain influence on it,so it needs to be taken into account when calculating accurately.The influence of temperature and humidity on the acoustic eigenfrequency of photoacoustic cells shows a positive linear growth law.The sensitivity of temperature effect decreases with the increase of resonator length,and the sensitivity of humidity effect decreases with the increase of temperature.When calculating the acoustic eigenfrequencies of photoacoustic units,the effect of humidity can be neglected under room temperature and low humidity.