The Effects of Incident Turbulence and Moving Wakes on Laminar Heat Transfer in Gas Turbines

Abstract

The effect of free-stream turbulence and moving wakes on augmenting heat transfer in accelerating laminar boundary layers is considered. First, the effect of free-stream turbulence is re-examined in terms of a Nusselt number and turbulence parameter, which correctly account for the free-stream acceleration and a correlation for both cylinders in crossflow and airfoils with regions of constant acceleration is obtained. This correlation is then used in a simple quasi-steady model to predict the effect of periodically passing wakes on airfoil laminar heat transfer. A comparison of the predictions with measurements shows good agreement.