EXPERIMENTS ON POROUS-WALL COOLING AND FLOW-SEPARATION CONTROL IN A SUPERSONIC NOZZLE

Technical Report · Mon Dec 01 04:00:00 EST 1958

OSTI ID:4296026

Green, L Jr; Nall, K L

Control of flow separation by fluid injection at one diverging boundary of a two-dimensional, transparentwalled de Laval nozzle was investigated by spark scblieren photography of dry-nitrogen flows expanded from two stagnation temperatures (600 and 990 deg F) and four stagnation pressure levels (250, 300, 350, and 400 psig).. Injection conditions at the permeable boundary were varied by the use of three grades of porous stainless steel with nominal mean pore diameters of 10, 20, and 30 microns. In addition to the case of no pressurized injection, nitrogen was forced through the steel by coolant reservoir pressures of 25, 50, and 100 psig. Pressure distribution measurements were made along the nonpermeable diverging boundnry. It was found that flow separation at expansion ratios approaching the optimum value for maximum thrust coefficient could be inducted at the porous wall by a local injection mass velocity of the order of a few percent of the local mainstream mass velocity. Separation at the solid boundary was not noticeably influenced by injection at the opposite wall, and the asyrnmetrical separation thus effected jet deflections of up to 10 deg at the lower stagnation-pressure levels. Variation of the wall heat-transfer condition by using increased stagnation temperatures (for comparison with previous cold- flow experiments) did not significantly influence separation behavior. Temperature measurements at the reservoir-face of the porous section, together with use of the Rubesin analysis for estimation of strearn-face Stanton numbers under injection conditions, permitted heat-transfer calculations which demonstrated the bigh effectiveness of the transpiration technique in controlling nozzle-wall temperatures. 207 references. (auth)

• Research Organization: Aerojet-General Corp., Azusa, Calif.
• NSA Number: NSA-13-005689
• OSTI ID: 4296026
• Report Number(s): WADC-TN-58-348; AGC-1490
• Country of Publication: United States
• Language: English

Related Subjects

BIBLIOGRAPHY
CONFIGURATION
COOLING
DISTRIBUTION
EXPANSION
FLUID FLOW
GAS FLOW
HEAT TRANSFER
JETS
MASS
MEASURED VALUES
NITROGEN
NOZZLES
NUMERICALS
PERFORMANCE
PHOTOGRAPHY
PHYSICS AND MATHEMATICS
POROSITY
PRESSURE
SEPARATION PROCESSES
STAINLESS STEELS
SURFACES
TEMPERATURE
VELOCITY