A Comparison of Techniques for Reconstructing Axisymmetric Reacting Flow Fields from Absorption Measurements

Abstract

“Onion peeling“, Abel transformation and Fourier convolution reconstruction techniques have been compared in terms of their ability to accurately reconstruct axisymmetric, non-reacting and reacting flow fields from computer simulated absorption measurements. The effect of the shape of the flow field, the number of measurements and the measurement error on reconstruction accuracy are studied. The reconstruction techniques are shown to yield different results from the same set of absorption data. The reasons for this are discussed. Analysis of the frequency spectrum of the data is shown to be very useful for estimating the number of measurements required for adequate sampling and for determining the cut-off frequency for selectively filtering high frequency noise components from measurements with random error. The effect of measurement error on the reacting flow reconstructions was found to be greatest in the temperature profiles.