Date of Award


Document Type


Degree Name

Master of Science


Department of Aeronautics and Astronautics

First Advisor

Marc D. Polanka, PhD.


Over the past several years, AFIT and the Air Force Research Laboratory have collaboratively investigated a novel combustor system that is compact in design and has potential use in an inter-turbine burner system. The ultra-compact combustor (UCC) design wraps the combustion section circumferentially around the axial core flow and exploits the use of high-g combustion. The combustor's volume and weight are reduced by integrating the exit compressor vane and the turbine inlet vane. This creates a new hybrid vane that resides directly below the circumferential combustor. Recently, a computational effort to understand the fundamental aspects of the UCC on a fighter scale model revealed that high temperatures are likely to occur on the hybrid vane. To address this issue, film-cooling is being explored for the UCC in a computational manner. Simulations of normal coolant hole, contoured trench, and hybrid normal and contoured trench configurations were performed for blowing ratios of M=1, 1.5 and 2. Secondary reactions formed due to the oxygen-rich coolant air reacting with unburned fuel as it exited the circumferential cavity. Although secondary reactions occurred, a decrease in unburned radicals was noticed at the exit of the UCC due to enhanced completion of reactions upstream.

AFIT Designator


DTIC Accession Number