Hilbert-Optic Diagnostics of Hydrogen-Oxygen Inverse Diffusion Flame

Abstract

The aim of this work is to adapt the methods of optical Hilbert diagnostics for the visualization and study of inverse diffusion H2/O2 flame. The diagnostic complex is implemented on the basis of the IAB-451 device with modified optical filtering. Visualization of phase perturbations induced by the studied medium in a probing multiwave light field is performed via polychromatic Hilbert and Foucault-Hilbert transformations in combination with registration and RGB-per-pixel processing of the dynamic structure of the images. From solution to the inverse problem of Hilbert optics using a physically justified initial approximation of the problem under consideration, the temperature field of the flame is reconstructed and the value of the H2, H2O, O2 and N2 concentrations may be restored.

Gauss-Newton Method in the Problem of Optimizing the Axisymmetric Phase Function Calculation Based on the Hilbert Diagnostic Data

“…The pixel size in the image corresponded to 1/30 mm when registering the optical signal in the experiments [3,4]. Therefore, the number of samples 𝑁 = 1801 in the interval [−𝑟 0 , 𝑟 0 ].…”

“…The Hilbert diagnostics results of reacting jets were previously presented in [3,4]. The possibility of polychromatic Hilbert visualization of phase optical density fields with temperature profile measurement in selected sections of the medium under study is shown using the example of an axisymmetric hydrogen-air diffusion flame and a candle flame using the Abel transform.…”