Combustion of free fuel droplets in a freely falling chamber

Unsteady Effects in Droplet Evaporation and Combustion

“…When the flame is in the NS region, the QS theory will not give correctly its position even in first approximation. The analysis presented here explains the fact (experimentally confirmed) that in many cases the QS analysis gives valid results regarding burning rates but not regarding flame position (Nuruzzaman and Beer, 1971;Krier and Wronkiewic, 1972;Rush and Krier, 1973;Isoda and Kumagai, 1958;Kumagai, Sakai, Okajima, 1971). An earlier attempt to solve this contradiction has been made by Chervinsky (1969), however, the mathematical approximations he uses do not appear to be justified, and his theory does not lead to useful results for the JVS-droplet lifetime.…”

“…In Figure 5 a comparison is given of the experimental results of Kumagai et al (1971) Regarding this point, it should be mentioned that if the flame would have been located clearly in the outer region, the theory here presented should not be applicable to this experiment, because the heat of reaction would be so large as to make the temperature of the flame considerably larger than the temperature at infinity, thus invalidating the assumption 6 = 1 + Ve 0* that allows to linearize the equations in the outer region.…”

Comprehensive study of initial diameter effects and other observations on convection-free droplet combustion in the standard atmosphere for n-heptane, n-octane, and n-decane

“…Though the burning rate is predicted to be constant and independent of time and droplet size, experiments show that the burning rate decreases as the initial droplet diameter increases and that it depends on time [3,13,14,[16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31] . This trend has not been fully explained, owing in part to the inability to model all of the important processes in droplet burning (i.e., unsteady transport, variable properties, soot formation, radiation, complex combustion chemistry).…”

Numerical Modeling of Steady Burning Characteristics of Spherical Ethanol Particles in a Spray Environment

“…Combustion of any liquid fuel as particles or droplets occurs in several practical systems including internal combustion engines and liquid fuel fed industrial furnaces. Experiments for the burning of liquid fuel particles have been carried out in the past by several researchers [2][3][4][5][6][7][8]. Suspended droplets, free droplets, and liquid fuel fed through porous spheres have been studied.…”