基于多波长激光吸收光谱技术的气体温度二维重建

激光吸收光谱技术在航空航天领域具有广泛的应用前景。文章利用多波长激光吸收光谱技术设计了气体温度二维重建系统,实现了燃烧场气体温度的二维重建,通过增加吸收谱线信息减少了投影个数。重建算法采用了遗传模拟退火结合序列二次规划(SQP)的混合算法,在实现全局寻优的同时提高了运算效率。建立了产物包含水的燃烧模型,利用8条水的近红外吸收谱线,对燃烧场温度进行了二维重建。通过在测量信息中添加不同比例的随机噪声,验证了算法的稳定性,并与双波长吸收法进行了对比。数值仿真实验结果表明,在低噪声环境下,两种方法的重建结果相当;但对于噪声较大的环境而言,多波长吸收法的重建效果更为稳定。

Two-dimensional reconstruction of gas temperature based on multi-wavelength laser absorption spectroscopy

The laser absorption spectroscopy has a broad application prospect in the field of Aeronautics and Astronautics. In this paper, a two-dimensional gas temperature is reconstructed by the multi-wavelengths diode laser absorption spectroscopy. A measurement system for the gas temperature is designed, and the number of projections is reduced by increasing the information of the absorption spectrum. A hybrid algorithm which combines the genetic simulated annealing with the sequential quadratic programming (SQP) is used to solve the problem, which improves the efficiency of the search. A combustion model of the product including water is established, and the temperature of the combustion field is reconstructed by using 8 near-infrared absorption spectrum lines of water. The stability of the algorithm is verified by adding different proportions of random noise in the measurement information, and the results are compared with the two wavelength absorption method. The experimental results show that the reconstructions of the two methods are equivalent in the low-noise environment, but with the increase of the noise, the multi-wavelength absorption method performs more stable.