Measurements of emitted radiation from the gases within the reaction zone of a combustor were performed. The combustor was a 30% flat (rectangular) model of an annular combustion chamber of a turbojet-engine. Nonpremixed, turbulent combustion was fueled by kerosene. The equivalence ratios were within the range of 0.15–0.75. The combustor had two quartz windows permitting optical observation of the combustion process. In an earlier work, the infrared emission from the efflux gases, the combustion products, just outside of the combustor exit plane, was investigated using an infrared camera, equipped with an interference bandpass filter. In the present study, infrared images of the combustion inside the chamber were obtained. The location of the high temperature recirculation zones can be identified in the infrared images obtained by the camera. In the visible spectral range, the emission of CH* radicals and C2* molecules from within the combustion chamber was investigated through the quartz window. These species exist within the reaction zones and play an important role in the combustion mechanism. Their excitation is mainly due to the chemical reactions and so they can serve for diagnosis of combustion processes in reaction zones. The emission from the combustor, in the visible range, was recorded with the aid of a fiber-optic based spectrometer. Local measurements of the emissions of the Swan bands of C2* molecules at 471 nm, 513 nm, 560 nm, vibronic band of CH* radicals at 431 nm and continuum emission of carbonaceous products of pyrolysis were recorded along the combustor centerline. The intensity is correlated with location of the combustion zones. The distribution of the emission was observed as being dependent on the global equivalence ratio.

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