Experimental reconstruction of the spatial density distribution of a nonreacting flow with a small number of absorption measurements

Abstract

The finite-domain direct inversion method, which was developed for use with sparse data sets, assumes smooth distributions, uses a priori information, and is well suited to the study of fluid mechanical and combustion phenomena. We successfully applied the inversion method, together with shifting functions that improve the reconstruction of distributions with nonzero values at the boundaries of their domain, to a real experimental situation and reconstructed the density distribution of methane in a nonuniform, nonreacting flow of methane and argon from projections measured optically. A point-by-point probe measurement of the methane concentration through the use of a hydrocarbon analyzer was performed to confirm the quality of the reconstruction of the optical measurement data with the inversion method.