LAUSR

Abstract The research investigates interdependent physical and chemical processes, occurring when a typical gel fuel is ignited by a hot particle. In the conducted experiments, high-speed video recording made it possible to establish the consistent patterns and characteristics of the ignition of gel fuel, based on an organic polymer thickener, by a disc-shaped steel particle 5 mm in radius and height. The fuel ignition delay times are 0.5–2.5 s when the initial temperature of the steel particle is varied from 1230 to 1500 K. A mathematical model of the investigated process was developed using experimental data obtained. It describes the interdependent processes of conductive heating and melting of gel fuel, melt evaporation, cooldown of the particle and its gradual immersion in the near-surface layer of the fuel, formation of a combustible gas–vapor mixture around the local heating source and its ignition under the conditions of diffusion-convective heat and mass transfer. The numerical simulation results are in good agreement with the experimental data. The developed mathematical model can be used in practice to predict the characteristics of gel fuel ignition by hot particles, when a group of factors in the particle – fuel – air system is varied in wide ranges.