基于双色法的碳烟火焰三维温度场计算层析成像测量

3D Temperature Field Measurement of Soot Flame Based on Computed Tomography Imaging with Two-Color Method

建立了一种基于多角度火焰光学投影信号获取的三维层析重建成像算法,用于测量不规则形态火焰的三维结构。通过搭建可旋转的射流燃烧装置建立不规则轮廓非预混稳定乙烯碳烟火焰,采用单一像增强相机(ICCD)从28个不同角度依次进行火焰自发光的全波段、550 nm和650 nm窄波段投影图像采集,结合自编制的三维重建程序与修正双色法,实现了碳烟火焰三维温度场测量。结果表明,三维重构算法能够再现火焰结构与温度场三维空间分布特性,温度测量值符合层流乙烯扩散碳烟火焰温度范围,采用任意不同角度投影图像数据的数目高于15个时,重构效果最好。

A three-dimensional(3D)tomographic reconstruction algorithm based on multi-angle optical projection signal acquisition images of flame was established,which can be used to measure the 3D structure of irregular flames.A rotatable co-flow jet burner was designed to generate the stable irregular-profile non-premixed ethylene soot flame,and an intensified charge-coupled device(ICCD)camera was used to sequentially capture the full band,550 nm,and 650 nm narrow band 2D projected images of the natural luminescence signals of stable flame with 28 different angles.Combined with the developed 3D reconstruction program and the modified two-color method,the 3D temperature measurement of stable soot flame was achieved.The results show that the reconstruction method can reproduce the 3D spatial flame profile and temperature field distribution characteristics.The measured temperature value agreed well with the temperature range of laminar non-premixed ethylene soot flame.Moreover,to achieve a better reconstruction result,the number of projected images from different angles should not be less than 15 by this method.