互相关函数法在声学测温技术中的应用研究

该文介绍了利用声学方法测量烟气温度的基本原理，并对声波飞渡时间的测量进行了计算机模拟分析和实验研究。利用信号处理技术中的互相关函数分析方法，计算声波发射端和接收端两路信号之间的时间延迟。采用计算机模型进行的研究表明，当接收端背景噪声和接收的信号水平相当时，在不作降噪处理的情况下，也能得到比较满意的分析结果。由于稳定周期信号作为测温声源在技术处理上有难度，该文设计了500—2000Hz范围内的扫频声波作为声源，对声波飞渡时间的测量进行了实验研究，结果表明该种声源和信号处理方法可以满足声学测温的技术要求。

THE RESEARCH OF ACOUSTIC MEASURING OF GAS TEMPERATURE EMPLOYING CROSS-CORRELATION ALGORITHM

In this paper basic theory of acoustic measurement of gas temperature is introduced. The metrical method of flight time of acoustic wave is analyzed by means of computer simulations as well as experiments. Cross-correlation function is found to be useful algorithm for detecting time delays between two signals. The pair of sound signals are acquired from the sound transmitter and receiver separately. Computer simulation shows that it is possible to operate with background noise almost at the same level to received signal without any additional denoise processing. There are some difficulties in processing employing steady periodic signals. A sweep-frequency from 500 to 2000Hz sound source is designed and applied in the experiments. The results show that the sound source and the signal processing method could satisfy the technical requirement of acoustic pyrometer.