Quantitative imaging of radiation intensity (QIRI) is a method of investigating temporally and spatially resolved radiation from species and particulates in turbulent flames and characterizing flame radiation statistics. The current study reports quantitative images of radiation intensity from a representative turbulent ethylene flame that matches the Reynolds number (15,200) of a non-sooting flame from the International Workshop on Measurement and Computation of Turbulent Non-premixed Flames. A calibrated high-speed infrared camera with four band-pass filters was used to acquire images of radiation intensity in wavelengths corresponding to carbon dioxide, water vapor, and soot. The luminous flame measurements show thin radiating structures corresponding to soot layers and higher mean and fluctuating radiation intensities compared to quantitative images of radiation intensity from a non-sooting flame. For centerline locations downstream of initial soot radiation detection, the temporal correlation of radiation from soot approaches zero more rapidly than radiation from carbon dioxide. The normalized probability density functions indicate that for centerline positions downstream of the initial soot radiation detection the PDF of soot radiation is skewed towards higher intensities while the PDF of carbon dioxide radiation is skewed towards lower intensities. The results of this work can be utilized for validation of models of soot formation, oxidation, and emission.
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