Date of Award

3-23-2018

Document Type

Thesis

Degree Name

Master of Science in Aeronautical Engineering

Department

Department of Aeronautics and Astronautics

First Advisor

Marc D. Polanka, PhD.

Abstract

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.

AFIT Designator

AFIT-ENY-MS-18-M-297

DTIC Accession Number

AD1056634

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