Date of Award
Master of Science in Aeronautical Engineering
Department of Aeronautics and Astronautics
Marc D. Polanka, PhD.
Film cooling is still a bustling research topic, especially with burgeoning manufacturing techniques on the horizon that will open the design space. However, despite the number of years that have gone into gas turbine design and research, evaluating cooling performance on components still presents challenges. This task becomes especially difficult and dangerous if trying to do so in realistic engine conditions. Therefore, the majority of film cooling research is performed at conditions far from realistic engine conditions, often using materials that would never hold up to turbine inlet temperature, and scaled to predict results at engine conditions. Previous film cooling investigations at the Air Force Institute of Technology have been conducted on both large and small scale experimental rigs. This thesis sought to investigate the effect that the geometric size differences had an overall effectiveness. To enable a comparison, the small scale rig performed experiments on a 1/9th scaled leading edge model. Slight differences in the coolant delivery method highlighted the importance of internal cooling and caused the results to match poorly. Additionally, this thesis also continued to investigate the relative importance of nondimensional parameters that relate film cooling performance within different temperature regimes. Tests were conducted to understand how temperature, Reynolds number, blowing ratio, and internal cooling configuration impacted the overall effectiveness. Thermal measurements were made through IR thermography on the Inconel 718 semi-cylinder leading edge model to support the research objectives.
DTIC Accession Number
Tewaheftewa, James G., "Investigation of Geometric and Thermal Scaling Effects on Simulated Turbine Vane Leading Edge Model" (2018). Theses and Dissertations. 1786.