Experimental study on the ignition delay characteristics of pyrolysis gas from kerosene with hydrogen peroxide addition

The ignition issue of the hypersonic aircraft remains a challenging task due to the extremely short residual time of milliseconds. To study the potential candidate of hydrogen peroxide for ignition enhancement, the ignition delay times of pyrolysis gas with the addition of 0–5000 ppm hydrogen peroxide were experimentally measured and quantitatively analyzed at temperatures of 833.8–962.1 K, equivalence ratios of 0.5–1.5, pressures of 31.9–48.8 bar, and the dilution of 45 vol% Ar. A novel injection system based on a Laval nozzle was designed to well atomize and evaporate the liquid hydrogen peroxide. The experimental results showed that the enhancing effect of hydrogen peroxide was proceeded by three stages, in which the decreasing efficiency gradually weakened with the increase of additive fraction. The ignition delay times of pyrolysis gas dramatically shortened by 66.1 % with 1000 ppm of hydrogen peroxide. Only a decrement of 19.1 % was obtained as the additive fraction increased from 1000 to 4000 ppm. The decline at 4000–5000 ppm even reduced to 2.0 %. It is suggested to add no more than 1000 ppm of hydrogen peroxide from the perspective of the highest acceleration efficiency on the ignition delay times of pyrolysis gas. •Additive effects of H2O2 on ignition properties of pyrolysis gas were revealed.•A novel setup for atomization and evaporation of H2O2 was designed.•Enhancing effects were operated by three stages with additive fractions.•1000 ppm H2O2 showed the greatest ignition acceleration efficiency.