Accession Number : ADA289459

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

Descriptive Note : Final rept.,

Corporate Author : AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING

Personal Author(s) : Lenertz, Joseph L.

PDF Url : ADA289459

Report Date : DEC 1994

Pagination or Media Count : 108

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=5.2x10(exp 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.

Descriptors :   *HEAT TRANSFER, *NOZZLES, *THROATS(EQUIPMENT), CONTROL, MEASUREMENT, RATIOS, AIR, PERFORMANCE(ENGINEERING), THIN FILMS, THESES, COOLING, REGIONS, REDUCTION, LOW VELOCITY, WALLS, FLOW, SIDES, HEAT FLUX, ROCKET ENGINES, SHOCK TUBES, SINTERING, HEAT TRANSFER COEFFICIENTS, RESISTANCE THERMOMETERS, SECONDARY INJECTION.

Subject Categories : Rocket Engines
      Physical Chemistry
      Thermodynamics

Distribution Statement : APPROVED FOR PUBLIC RELEASE