关键词: 十氢萘, 着火延迟时间, 激波管, 敏感度分析, 动力学机理

Abstract:

Ignition delay measurements of gas-phase decalin/air mixtures were performed in a shock tube at temperatures of 950-1395 K, pressures of 1.82×10⁵ to 6.56×10⁵ Pa, and equivalence ratios of 0.5, 1.0, and 2.0. The ignition delay time was determined using the reflected shock wave pressure and CH^* emission monitored at the sidewall. The effects of temperature, pressure, and equivalence ratio on the ignition delay time of decalin were investigated systematically. The results show that increasing the temperature or pressure decreases the ignition delay time. Opposite ignition delay dependences on the equivalence ratio were observed for decalin/air at high and low pressures, for the first time. At 15.15×10⁵ Pa, the fuel-rich mixture showed the shortest ignition delay time, and the fuel-lean mixture gave the longest one. However, at 2.02×10⁵ Pa, the fuelrich mixture had the longest ignition delay time. Comparisons of the experimental data with predictions based on the available kinetic mechanism were made; the trends in the experimental data were in good agreement with the predictions under all conditions studied. A sensitivity analysis was performed to obtain insights into the effects of the equivalence ratio on the ignition delay time at low and high pressures. The results show that ignition is mainly controlled by the reaction H+O₂=OH+O at 2.02×10⁵ Pa. However, the reactions involving decalin and its corresponding radicals play important roles at 15.15×10⁵ Pa.

Key words: Decalin, Ignition delay time, Shock tube, Sensitivity analysis, Kinetic mechanism