Date of Award
Doctor of Philosophy (PhD)
Department of Aeronautics and Astronautics
Richard D. Branam, PhD
This study quantified the effects of discrete wall-based film cooling in a rocket with curved walls. Simulations and experiments showed decreasing with wall radius of curvature, holding jet diameter constant, improves net heat flux reduction (NHFR) and adiabatic effectiveness (η) for 90˚ compound injected cylindrical jets, though η is reduced at the highest curvature. NHFR and η improved further with a high favorable stream-wise pressure gradient (K=2.1x10-5) at all tested blowing ratios, but were affected little by a high density ratio (DR=1.76) using carbon dioxide as the coolant. Experiments were run at a Reynolds number of 31K and a free-stream turbulence intensity of 26% with varying wall and jet radii. Simulations showed the Rannie transpiration model may be used to predict the cooling performance of a wall with full coverage film cooling using a correction formula based on the hole coverage area. Three improvements were made to the method of simultaneous acquisition of adiabatic wall temperature and heat flux coefficient: solving for the needed variables via a multi- point non-linear least squares curve fit instead of a two-point direct solution; correctly applying the free-stream fluid temperature boundary condition to account for drifting temperature instead of assuming it to be constant; and showing a repeatable way to reduce uncertainty in the test start time.
DTIC Accession Number
McCall, Jonathan F., "Discrete Film Cooling in a Rocket with Curved Walls" (2009). Theses and Dissertations. 2026.