NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Mixing of Supersonic StreamsThe Strutjet approach to Rocket Based Combined Cycle (RBCC) propulsion depends upon fuel-rich flows from the rocket nozzles and turbine exhaust products mixing with the ingested air for successful operation in the ramjet and scramjet modes. It is desirable to delay this mixing process in the air-augmented mode of operation present during low speed flight. A model of the Strutjet device has been built and is undergoing test to investigate the mixing of the streams as a function of distance from the Strutjet exit plane during simulated low speed flight conditions. Cold flow testing of a 1/6 scale Strutjet model is underway and nearing completion. Planar Laser Induced Fluorescence (PLIF) diagnostic methods are being employed to observe the mixing of the turbine exhaust gas with the gases from both the primary rockets and the ingested air simulating low speed, air augmented operation of the RBCC. The ratio of the pressure in the turbine exhaust duct to that in the rocket nozzle wall at the point of their intersection is the independent variable in these experiments. Tests were accomplished at values of 1.0, 1.5 and 2.0 for this parameter. Qualitative results illustrate the development of the mixing zone from the exit plane of the model to a distance of about 19 equivalent rocket nozzle exit diameters downstream. These data show the mixing to be confined in the vertical plane for all cases, The lateral expansion is more pronounced at a pressure ratio of 1.0 and suggests that mixing with the ingested flow would be likely beginning at a distance of 7 nozzle exit diameters downstream of the nozzle exit plane.
Document ID
19990114847
Acquisition Source
Marshall Space Flight Center
Document Type
Conference Paper
Authors
Hawk, C. W.
(Alabama Univ. Huntsville, AL United States)
Landrum, D. B.
(Alabama Univ. Huntsville, AL United States)
Muller, S.
(Alabama Univ. Huntsville, AL United States)
Turner, M.
(Alabama Univ. Huntsville, AL United States)
Parkinson, D.
(Alabama Univ. Huntsville, AL United States)
Date Acquired
August 19, 2013
Publication Date
December 1, 1998
Publication Information
Publication: JANNAF Airbreathing Propulsion Subcommittee and 35th Combustion Subcommittee Meeting
Volume: 1
Subject Category
Fluid Mechanics And Heat Transfer
Funding Number(s)
CONTRACT_GRANT: NCC8-123
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

Available Downloads

There are no available downloads for this record.
No Preview Available