Date of Award

12-9-2009

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Department of Aeronautics and Astronautics

First Advisor

Richard D. Branam, PhD

Abstract

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.

AFIT Designator

AFIT-DS-ENY-09-D02

DTIC Accession Number

ADA508041

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