Elevated freestream turbulence effects on heat transfer for a gas turbine vane

Abstract

High freestream turbulence levels have been shown to greatly augment the heat transfer along a gas turbine airfoil, particularly for the first stage nozzle guide vane. For this study, augmentations in convective heat transfer have been measured for a first stage turbine vane in the stagnation region, along the mid-span, and along the platform resulting from an approach freestream turbulence level of 19.5%. In addition to quantifying surface heat transfer, boundary layer measurements have been made to better understand high freestream turbulence effects. Although there are a number of correlations that have been developed for scaling freestream turbulence augmentations to heat transfer, the results of this study indicate that these correlations are not successful in predicting heat transfer for various regions along a turbine vane.