A simultaneous measurement technique for soot temperature and volume fraction of sooting flames considering self-absorption through hyperspectral imaging

Abstract

Due to the complex optical properties of sooting flames, the accuracy of flame emission-based measurement techniques depends on an appropriate self-absorption correction strategy. Thus, this paper presents a novel iterative procedure to retrieve the soot temperature and volume fraction of sooting flames along with a self-absorption correction strategy through hyperspectral imaging. Numerical simulations were carried out on suppositional flames to investigate the performance of the proposed technique. Relative errors obtained from the simulations are below 1.5%, indicating a better accuracy can be achieved by the proposed reconstruction technique. A hybrid camera hyperspectral video imaging technique is designed and implemented with the concept of compressed sensing. A significant improvement in flame spectrum acquisition has been observed. Experiments were carried out under ethylene-air diffusion flames to validate the technique. The reconstructed flame soot temperature and volume fraction distributions demonstrated that the proposed hyperspectral video imaging technique improves the soot temperature and volume fraction reconstruction accuracy.