Effects of Blowing Ratio on Heat Transfer to the Throat Region of a Porous-Walled Nozzle

Author

Joseph L. Lenertz

Date of Award

12-1994

Document Type

Thesis

Degree Name

Master of Science in Astronautical Engineering

Department

Department of Aeronautics and Astronautics

First Advisor

Jerry Bowman, PhD

Abstract

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.

AFIT Designator

AFIT-GA-ENY-94D-7

DTIC Accession Number

ADA289459

Recommended Citation

Lenertz, Joseph L., "Effects of Blowing Ratio on Heat Transfer to the Throat Region of a Porous-Walled Nozzle" (1994). Theses and Dissertations. 6330.
https://scholar.afit.edu/etd/6330