Single shot CARS thermometry of hydrogen-contaning multicomponent gaseous mixtures at high pressure and high temperature

摘要

We demonstrate the feasibility of the proposed new approach to CARS thermometry of hydrogen-containing mixtures with simultaneous measurement of the intensities of a hydrogen spectrum Q-branch lines and their linewidths in a single laser shot by means of a spectrograph combined with an interferometer, that have orthogonal directions of dispersions. This provides correct temperature evaluation that takes into account the linewidths, measured directly. The experiments were carried out in a H_(2):N_(2) velence 1:10 mixture in a heated cell at a temperature of 1050 K. The values of gas mixture temperature, that were defined in a pressure range of 2 - 9 MPa from DBB CARS spectra taking into account linewidth corrections, coincide with a thermocouple measurements within approx 2 percent. Without these corrections the discrepancies increase up to 5 percent. The proposed approach can be applied to CARS thermometry in the course of investigations of H_(2) and hydrocarbon combustion without the necessity to measure species concentrations, and does not require the knowledge of the line-broadening coefficients.