A Quasi-Steady Approach of Wake Effects on Leading Edge Transfer Rates

Abstract

Mass transfer experiments are described for a circular cylinder with a steady incident wake flow. Measurements of the velocity, turbulence intensity, intermittency, and integral length scale within the wake are presented together with measurements of the stagnation mass transfer as a function of the cylinder’s position in the wake. Comparison of the results indicates that although the increase in mass transfer occurring along the wake centerline depends on the turbulence intensity, length scale, and possibly other factors, the functional relation with respect to the cylinder’s lateral position in the wake depends on the intermittency and not turbulence level. In addition, a simple quasi-steady theory is developed to account for the unsteady effects caused by the passing of wakes in the incident flow on the stagnation transfer rate at the leading edge of a gas turbine airfoil.