Date of Award
Master of Science in Astronautical Engineering
Department of Aeronautics and Astronautics
Jerry Bowman, PhD
This experiment analyzed the effects of blowing ratio on heat transfer to the throat region of a porous-walled nozzle, using the AFIT low speed shock tube. Heat flux data were taken from both sides of a two-dimensional Mach 2.0 Re-m=5.2x107 nozzle using thin film resistance thermometers. One side was transpiration-cooled by secondary air injection through a sintered wall, while the other side served as a control. Control results were validated using empirical relations, and cooled side results showed up to a 14% reduction in heat transfer coefficient at blowing ratios of only 0.51%. The linear nature of cooling effectiveness at these low blowing ratios allowed a modification of nozzle heat transfer equations to include a blowing ratio parameter. Disturbance of primary flow was also minimized, causing no measurable reduction of nozzle performance.
DTIC Accession Number
Lenertz, Joseph L., "Effects of Blowing Ratio on Heat Transfer to the Throat Region of a Porous-Walled Nozzle" (1994). Theses and Dissertations. 6330.