基于自发辐射断层成像技术的二维预混火焰重建

Reconstruction of Two-Dimensional Premixed Flame Based on Computed Tomography of Chemiluminescence

将燃烧诊断中的自发辐射测量与计算机断层成像技术(CT)相结合,可克服自发辐射测量结果为空间积分的缺点,获得火焰的空间结构.首先对投影重建算法进行优化,并利用仿真实验,研究了优化重建算法对重建质量的影响;然后设计并实现了二维预混火焰,测量了OH*和CH*的自发辐射,并重建了火焰结构;最后将重建图像与二维火焰的真实图像进行对比.结果表明,利用燃烧的先验知识,能够进一步优化重建算法,提高重建质量;采用自发辐射断层成像技术(CTC)能够对火焰进行较好的重建,归一化均方根距离参数d和归一化平均绝对距离参数r均能达到10-1的数量级,可以较准确地描述火焰结构.该研究方法可以很方便地扩展到对三维火焰结构的研究.

The space structure of flames can be obtained by combining spontaneous emission measurement in com- bustion diagnosis with computed tomography （CT）, which can overcome the shortcoming that the spontaneous emis- sion measurements are space integral ones. First, the reconstruction algorithm is optimized in this paper, and the influence of the optimization algorithm on the quality of reconstruction is studied by carrying out phantom experi- ments. Then, a two-dimensional premixed flame is designed and implemented to measure the spontaneous emission of OH＊ and CH＊ for reconstructing the flame structure. Finally, the reconstructed images are compared with the lat- eral accumulative projection of the two-dimensional flame. The results show that the use of prior knowledge can fur- ther optimize the reconstruction algorithm and improve the quality of reconstruction, and that the computed tomogra- phy of chemiluminescence （CTC） can be employed to carry out the good reconstruction of flames and depict the flame structure accurately. This research method can be easily extended to the study of three-dimensional flames.