The burning of single drops of fuel in oxidizing atmospheres

The burning of single, isolated drops of fuel in a quiescent oxidizing atmosphere has been investigated theoretically and experimentally. Two theories are presented. The first, called the diffusion theory, rests on the assumption that the rate of burning is determined by the rate at which the reactants are delivered by diffusion to the flame front surrounding the liquid drop. The second, or thermal theory is based on the assumption that chemical reaction rates govern the rate of burning of the droplet. The effects on droplet burning rate of changes in the composition, temperature, and pressure of the surrounding oxidizing atmosphere have been investigated experimentally. A preliminary study has also been made of the effect of forced convection on droplet burning. It is found that the thermal theory of droplet burning does not adequately explain the observed variations in droplet burning rate as the composition and temperature of the surrounding atmosphere are varied. On the other hand, substantial agreement is found between the results of the diffusion theory and experimental data.