ABSTRACT
The broad definition encompasses a wide variety of processes—for example, a pan of oil burning in air, an aluminum sheet burning in a supersonic air stream, a lighted candle, a forest fire, and a fuel droplet burning in oxygen in a rocket engine. In a restricted sense, a diffusion flame may be defined as a nonpremixed, quasisteady, nearly isobaric flame in which most of the reaction occurs in a narrow zone that can be approximated as a surface. Carbon combustion is an interesting illustration of gas-solid reactions and also is relevant to the practical subject of the combustion of coal, since later stages of coal combustion, following devolatilization, mainly involve carbon burning. A variety of phenomena are exhibited by the burning of a spherical fuel particle in an infinite oxidizing atmosphere. A number of theoretical studies of the quasisteady, spherically symmetrical burning of monopropellant droplets have been published.
