Development of synchrotron X-ray computed tomography for quantitative measurements of gas-phase temperature in reacting flows

Laboratory X-ray computed tomography systems have recently been used to measure the 3D temperature field in reacting flows. The present work extends this technique to micro-scale resolution by employing a synchrotron source. Of particular focus is hereby the quantification of the accuracy and uncertainties of the measurements and the examination of conditions required to retrieve the gas temperature from X-ray absorption measurements. The specific advantages and constraints of using a synchrotron source are discussed and the experimental procedure is detailed. Cold-flow calibration experiments as well as measurements on a flat-flame are reported. The merit of this measurement technique for micro-scale applications with optically inaccessible media is then illustrated in the context of a porous media burner. The 3D temperature field extracted from X-ray computed tomography measurements is examined to identify interstitial combustion modes and flame/wall coupling within the porous matrix.