Characteristics of micro-explosive dispersion of gel fuel particles ignited in a high-temperature air medium

• Micro-explosive dispersion of gel fuel particles occurs when they are ignited in high-temperature air. • Gel fuels with fine particles and without them feature different ignition mechanisms. • Average velocities of child droplets and size of the burnout area are 2 m/s and 8.0 cm 3 , respectively. • The heat generation rate of 10 mg gel fuel is about 190 W (vs. about 25 W for liquid fuel in original state) • Flame temperature during gel fuel combustion was for the first time established with two-color pyrometry. The characteristics of processes developing during the ignition and combustion of single gel fuel particles with a mass of 10 mg in a high-temperature motionless air medium were investigated by means of a hardware and software system. The system featured a high-speed video camera, LED spotlights and a laptop with commercial and custom software. A group of fuel compositions was derived from oil-filled cryogels alone and with the addition of fine solid combustible components. Polyvinyl alcohol with 10 wt% in an aqueous solution was used as an organic polymer thickener. When exposed to rapid heating, fuel compositions (oil + aqueous solution of PVA + emulsifier; oil + coal dust + aqueous solution of PVA + emulsifier) were characterized by the micro-explosive dispersion of particles. The velocities of fine fragments after the micro-explosive dispersion of a fuel melt droplet were established when the air temperature was varied in the range of 700–1000 °C. The gas–vapor mixture temperature in the region of the fuel gas-phase combustion was determined using the original two-color pyrometry technique.