带压燃烧场2D温度分布的激光吸收光谱测量初步研究

Preliminary Study on 2D Temperature Distribution in Pressure Combustion Field by Using Tunable Diode Laser Absorption Spectroscopy

关键词:  带压燃烧场  可调谐半导体激光吸收光谱  计算机断层扫描  二维温度分布  时间分辨

Key words:  Pressure combustion field  Tunable diode laser absorption spectroscopy  Computed tomography  Two-dimensional temperature distribution  Time-resolved

摘要:

以实现冲压发动机等场合的高压燃烧流场诊断为目标，采用可调谐半导体激光吸收光谱（TDLAS）技术对带压燃烧流场的温度诊断进行初步研究。使用一种光谱耦合的CT重构方法，以误差平方和与零均值归一化互相关作为评价指标分析CT-TDLAS的重构精度。搭建带压燃烧腔温度分布测量的实验系统，使用压力传感器和CCD相机记录带压点火燃烧过程变化；使用调谐范围为1335~1375nm宽波段输出的半导体激光，对燃烧腔内带压点火燃烧过程进行了时间分辨的二维温度分布重建。实验结果表明：CT-TDLAS具有较高的重构精度；燃烧过程的压力变化趋势、火焰变化趋势及时间分辨二维温度分布变化趋势，三者保持一致；在带压条件下，CT-TDLAS可以实现高分辨率的时间分辨温度测量，反应定量的温度分布变化信息，为带压及进一步的高温高压燃烧流场的诊断提供帮助。

Abstract:

Aiming to achieve the combustion diagnosis of high pressure combustion field such as scramjet， Tunable Diode Laser Absorption Spectroscopy （TDLAS） was used to develop preliminary research on the temperature diagnosis of combustion with pressure condition. A Computed Tomography （CT） algorithm according to spectrum coupling was used to reconstruct two-dimensional temperature distribution. Using the sum of squared differences and the zero mean normalization cross correlation as the evaluation indicators which were able to analysis the reconstruction accuracy of CT-TDLAS. A pressure combustion chamber temperature distribution measurement experimental system was set up. With pressure sensor and CCD camera， the changing of the pressure and flame which contented combustion ignition process under pressure condition were recorded. Using wide-band tunable diode laser which can achieve 1335~1375nm output to reconstruct time-resolved two-dimensional temperature distribution. The experimental results show that CT-TDLAS has high reconstruction accuracy， the changing tendencies of pressure， flame and time-resolved two-dimensional temperature distribution result are similar， CT-TDLAS can achieve high-resolution time-resolved 2D temperature measurement and provide quantitative temperature distribution information to the research of combustion with pressure condition， which can give help to diagnosis of pressure combustion as well as further high temperature and high pressure combustion flow field.