Three-dimensional tomographic reconstruction of the luminosity distribution of a combustion flame

This paper presents the design, implementation, and evaluation of a 3-D imaging system for the reconstruction of the luminosity distribution of a combustion flame. Three identical red-green-blue charge-coupled device cameras together with appropriate optical transmission units are used to capture concurrently six equiangular 2-D images of a flame. A new tomographic approach that combines the logical filtered back-projection and the algebraic reconstruction technique is proposed to reconstruct flame sections from the images. A direct comparison between the proposed approach and other tomographic algorithms is performed through computer simulation for different test templates and number of projections. Experimental tests were undertaken using both gas- and coal-fired flames in order to evaluate the effectiveness of the system. This research has led to the establishment of an effective tool for the reconstruction of the luminosity distribution of flame sections and, ultimately, the quantitative characterization of the interstructures of a combustion flame.