Rapid ignition of fuel mixtures is crucial for efficient operation of airbreathing engines. This study investigates the ignition delay times of ethylene-air, ethylene-oxygen, and Propulsion grade Kerosene-air mixtures under various conditions relevant to airbreathing propulsion systems. Experiments were conducted using a shock tube to measure ignition delay times over a wide range of temperatures (800–1700 K) and equivalence ratios (0.5–1.5). The effects of temperature, pressure, and fuel type on ignition delay were examined. Results demonstrate that ignition delay decreases monotonically with increasing temperature and pressure for all fuel mixtures. A comparison between ethylene and Propulsion Grade Kerosene revealed that the latter exhibits sufficiently short ignition delay times for practical applications in airbreathing engines. Additionally, kinetic modeling was performed using various reaction mechanisms to validate the experimental results, ensuring consistency and reliability of the findings across the range of tested parameters.
Kesavan et al. (Mon,) studied this question.