结合吸收光谱与互相关法的燃气速度测量方法研究  

Research on Measurement Method of Gas Velocity Combined Absorption Spectroscopy Technique and Cross-Correlation

作　　者：刘佩进[1] 王志新[1] 杨斌[2] 魏祥庚[1] 

机构地区：[1]西北工业大学燃烧热结构与内流场重点实验室,陕西西安710072 [2]上海理工大学颗粒与两相流测量研究所/上海市动力工程多相流动与传热重点实验室,上海200093

出　　处：《光谱学与光谱分析》2017年第2期532-536,共5页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(51206136);上海高校青年教师培养资助计划项目(ZZslg15002)资助

摘　　要：针对可调谐半导体激光器吸收光谱(TDLAS)基于多普勒效应测速方法在燃气流速测量中频移量小、误差较大的问题,提出了结合固定波长吸收光谱法与互相关法的燃气速度测量方法。考虑碳氢燃料燃烧产物特点,选取H2O分子7 185.597cm^(-1)吸收谱线,通过布置上下游两束固定波长吸收光谱测点,分析两信号的互相关特性来计算得到燃气速度。利用平面火焰炉实验系统对该方法测量燃气速度开展实验研究,获得了变工况下燃气速度随时间的变化情况。在相同工况下开展数值计算,将测量结果与数值模拟计算结果进行对比,相对偏差不超过8%。同时将该方法初步应用于煤油燃料火箭基组合循环发动机(RBCC)的高速羽流速度测量,获得了上下游探测器脉动信号,通过互相关分析计算得到了羽流速度,验证了该方法的可行性。实验结果表明,该燃气速度测量方法具有测量范围宽、测量精度高,环境干扰小等优点。提出的方法为发动机燃气速度测量提供一种简单可靠的测量方法。For the small frequency shift and large error of tunable diode laser absorption spectroscopy（TDLAS）velocity method based on Doppler Effect in measuring the gas velocity,velocity measurement method combined fixed wavelength absorption spectroscopy and cross correlation is proposed in this paper.Considering the characteristics of the hydrocarbon fuel combustion products,7 158.597cm- 1 absorption line of H2 O molecular was selected.Through arranging two beams of fixed wavelength absorption measurement point of upstream and downstream,the gas velocity can be calculated by analyzing the cross-correlation properties of the two signals.The flat flame burner experiment system was used in the experimental research of the velocity measurement.The change of gas velocity with time under variable working condition was obtained.Under the same condition,numerical calculation is carried out.And the measurement results are compared with the results of the numerical simulation with relative deviation less than 8%.Then the method is preliminarily applied to measure the high speed plume of the kerosene-fueled Rocket Based Combined Cycle（RBCC）engine,and the upstream and downstream fluctuant signals of detectors were obtained.The velocity of the plume was calculated with cross correlation analysis which verifies the feasibility of this method.The experimental results show that the gas velocity measurement method has a wide measuring range with high measuring accuracy and little environment interference.The method proposed in this paper provides a simple and reliable method for the measurement of engine gas velocity.

关 键 词：吸收光谱 TDLAS 互相关法 速度测量 燃烧诊断 

分 类 号：O433[机械工程—光学工程]