ABSTRACT
This chapter uses reacting flows as an illustration for mass transfer and specifically consider diffusion flames. It aims to introduce microscales for turbulent flames, to construct models for fuel consumption, and to correlate experimental data. The chapter begins with forced flames and, subsequently proceed to buoyancy-driven flames. The dimensional arguments on laminar diffusion flames are extended to buoyancy-driven turbulent diffusion flames and pool fires by the recent developments on turbulent natural convection. The proposed models for laminar and turbulent flames and fires exclude any effect of radiation. Because of different intrinsic nature of radiation and conduction (or any diffusion), the Schvab-Zeldovich transformation used in the study no longer applies to radiation-affected flames. On intuitive grounds, the emission effect of radiation has been incorporated into the heat of combustion and the latent heat of evaporation by fractional lowering of these properties.
