On the influence of chemical kinetics on the combustion of fuels

Abstract

The influence of chemical kinetics on the combustion of fuel droplets is studied by means of a theoretical model of the process which considers spherical symmetry and quasi-stationary conditions. Chemical kinetics is approximated by means of an overall reaction rate of the nth order. Results are expressed as a function of the product of the pressure to the n/2th order times the droplet radius. It is shown that there exists a minimum value of such product under which an individual droplet cannot sustain a flame. An experimental investigation was also carried out, by burning in air at variable pressure fuel droplets suspended of thin quarts fibres. The laws of variation of both flame and droplet diameter as functions of time were obtained as well as the minimum values of the droplet diameters for combustion as a function of pressure. It is shown that all experimental results are in excellent qualitative agreement with those predicted by theory.