摘要
声场中的粒子振速是评价空气声场特性的一个重要参量。在平面波声场中，通过获取激光多普勒测速仪对不同声压级声场中散射粒子产生的光电信号，采用光子自相关法对原始多普勒信号进行处理，粒子的速度量值根据相关函数的时间特征值得出，并与传声器测量声压值计算的粒子振速值进行比较。在原有自相关算法的基础上，利用样条插值法来估计相关周期，减小原有信号频偏与多普勒频率之比并非整数倍的引入的差异。实验结果表明，光子相关法能够获得声场中的粒子振速，与传声器测量值吻合较好，当振速较大时，插值法有利于减小测量偏差。在96-110 dB 的声压量值范围内，光子相关法与传声器测量值之间的振速偏差优于0.7 dB。
The particle vibration velocity is an important parameter to evaluate the characteristics of the sound field. Photoelectric signal of scatter light was obtained laser Doppler velocimetry at different sound pressure level in plane wave sound field. And the Doppler signal was processed by autocorrelation method,the velocity can be calculated based on the time of characteristic values ？？of the correlation function and compared with that of microphone. Furthermore,on the basis of the autocorrelation algorithm,the difference which caused by the ratio of the original signal frequency offset and the Doppler frequency is not an integer multiple was reduced by the interpolation method. The results demonstrate that the photon correlation method is able to obtain particle vibration velocity of the sound field. and results show good agreement with that measured by microphone,interpolation method is conducive to decreasing the deviation when velocity is large relatively.The deviation of the two methods is less than 0. 7dB at the sound pressure level from 96 dB to 110 dB.
出处
《计量学报》
CSCD
北大核心
2014年第4期363-367,共5页
Acta Metrologica Sinica
关键词
计量学
粒子振速
声场
激光多普勒
自相关法
插值法
Metrology
Particle vibration velocity
Laser Doppler
Autocorrelation method
Interpolation method
