Optical Diagnostics of Temperature and Structural Parameters of an Axisymmetric Flame

Abstract

In this paper a method for restoring the parameters of multicomponent media for optical diagnostics of jet using the example of a hydrogen-air flame study is considered. Hilbert visualization and numerical modeling of phase perturbations induced by the studied medium in the probing light field are used. The study of the burning jet was carried out using the methods of Hilbert op-tics and Abel transformation in the model of axial symmetry of the torch. A software package has been developed that implements a direct solution to the problem: calculation of the spatial optical phase structure of the flame and its corresponding hilbertograms based on the temperature and molar concentrations of the combustion products of the mixture. The reliability of the obtained results is confirmed by comparing the Hilbert structures obtained in the experiment and the reconstructed optical density field of the phase using the Abel transform. The results of the comparison are used as a quality criterion for modeling the phase structure and temperature field in the study of the combustion process. The developed method can be used to solve the in-verse problem of restoring the temperature field from the Hilbert image of the phase structure of a hydrogen-air flame in the approximation of axial symmetry. The research is motivated by the scientific and practical significance of the problem, which consists in finding methods for controlling the structural and thermodynamic parameters of reacting jets and flames.