Heat transfer research on gas turbine airfoils at NASA GRC

The turbine gas path is a very complex flow field due to a variety of flow and heat transfer phenomena encountered in turbine passages. This manuscript provides an overview of the current work in this field at the NASA Glenn Research Center (GRC). Based on the authorʹs preference, however, more emphasis is on the computational work. There is much more experimental work in progress at GRC than that reported here. Specifically, the external flow and heat transfer characteristics are described over smooth and rough turbine blades for a range of parameter values. For smooth blades, the effect of film-cooling holes as well as internal cooling channels with ribs and bleed holes is considered. Studies on the blade tip region, susceptible to burnout and oxidation due to high thermal loading, are also described. Wherever possible, predictions of heat transfer coefficient on the real blade surface, obtained using in-house-developed codes, are compared with the available experimental data. Suggestions for further work are outlined.