Effects of Blowing Ratio on Heat Transfer to the Throat Region of a Porous-Walled Nozzle.
AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING
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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 Rem5.2x10exp 7 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.
- Rocket Engines
- Physical Chemistry