乙醇氧化基态 OH 浓度时程吸收光谱诊断

To provide micro-dimensional validation data for kinetic models of ethanol combustion reactions over a wide range of temperatures, pressures and equivalence ratios, OH time histories concentrations of two ethanol diluted mixtures (equivalent ratio of 0.5 and 1.0) were measured using a kinetic shock tube combined with a diagnostic technique of UV absorption spectroscopy in the temperature range of 1200∼1700 K. In order to target various pressures, diagnostic wavelengths in the OH A-X(0,0) transition at 306.6868 nm and 306.47 nm were chosen. The experiments effectively expanded the working conditions of the microscopic verification data of the ethanol kinetic model: low-pressure experiments expanded the temperature boundary; high-pressure experiments data were the first published OH time-history data with good repeatability. Results revealed the temperature-dependence on the evolution of OH concentration during the ethanol oxidation. The selected four representative ethanol kinetic models can only predict the shape of the OH profiles, but failed to predict the concentration value and ignition delay time. While adjusting the reaction rate constant within the experimental uncertainty can effectively improve the model’s prediction of the ignition delay time, it cannot simultaneously guarantee a high-accuracy prediction of the OH peak value. Therefore, the reaction groups are screened by kinetic analysis to give suggestions on the direction of further optimization of the ethanol combustion reaction kinetic model.