Infrared Emission from High-Temperature H_2O(v_2): A Diagnostic for Concentration and Temperature

摘要

A shock tube system was used to produce known concentrations of water at combustion temperatures so that the infrared radiance from a portion of the H_20(v_2) band could be measured as a function of temperature and wavelength. The resulting data set was used to determine the efficacy of a spectral emission diagnostic for H_20 temperature and column density at the exit plane of a supersonic combustor. Temporally and spectrally resolved, optically thin infrared emission, at 13 wavelengths between 6.5 and 9.5/μm, was observed from shock- heated H_20/N_2, H_2/O_2/N_2, and H_2/O_2/Ar mixtures, at pressures of 1 and 5 atm and temperatures between 1400 and 3000 K. Least-squares analysis of the temperature-dependent intensities for each wavelength channel gave parameters that accurately describe the radiance as a function of wavelength and temperature over the entire temperature range of the measurements.