Heat and Mass Transfer in a Boundary Layer in Evaporation and Combustion of Ethanol in a Turbulized Air Stream

Abstract

The influence of the dynamic properties of external flow on mass transfer in a boundary layer was investigated experimentally. The air stream turbulence was changed from 1% to 26% with the aid of lattices. The edges of height up to 15 mm were installed at the beginning of the boundary layer. The influence of viscosity was evaluated from comparison of experimental data for cases with combustion and without it. It is revealed that the extremes of mass transfer parameters exist for certain combination of the main stream turbulence level and the height of the edge. Without combustion it is a maximum of evaporation rate. With combustion - the flame breakdown main stream velocity maxima, and also it is the minimum of burning rate. In both cases the multiple changes of mass transfer intensity are noted. The reasons of their appearance are analyzed.