Abstract
An experimental study has been performed under microgravity conditions to obtain the detailed information needed for the deep understanding of the combustion phenomena of a fuel droplet which autoignites in supercritical gaseous environments. In the present study, the primary attention was focused on the ignition delay. 1-Octadecanol was selected as the test fuels. The mixtures of oxygen and carbon dioxide and oxygen and nitrogen were used as the ambient gas. The ambient pressure was extended up to pressures around 2 times the critical pressure of the fuels tested. The ignition delay was found to have a minimum around the ambient pressure equal to the critical pressure of the fuel, and a maximum in 1.5 times the critical pressure. Higher oxygen concentration of the ambient gas caused shorter ignition delay at ambient pressures equal to or above 1.5 times the critical pressure.
