Turbulent forced diffusion flames

A microscale, imageis introduced for turbulent diffusion flames, where η and σβ respectively, are the Kolmogorov scale and the flame Schmidt number. In terms of this scale, the turbulent mass transfer integrated over a length l of a liquid fuel is shown to be image, where μ is the dynamic viscosity and B is the transfer number, image, where YO is the mass fraction of oxidizer, YO∞ its ambient value, Q the heat release for a simple global chemical reaction, and vO and MO the oxidant stoichiometric coefficient and molecular weight, respectively, hw = cp(Tw - T∞), cp the specific heat of gas, Tw and T∞ the fuel and ambient temperatures, respectively, and hfg the heat of evaporation. It is shown by the similarity between the mass and momentum transfer, image being the drag coefficient, and that image where the subscript B = 0 for the case without boundary mass transfer. The agreement between the model and the sparse experimental data is reasonable.