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Characterization of Three-Stream Jet Flow FieldsFlow-field measurements were conducted on single-, dual- and three-stream jets using two-component and stereo Particle Image Velocimetry (PIV). The flow-field measurements complimented previous acoustic measurements. The exhaust system consisted of externally-plugged, externally-mixed, convergent nozzles. The study used bypass-to-core area ratios equal to 1.0 and 2.5 and tertiary-to-core area ratios equal to 0.6 and 1.0. Axisymmetric and offset tertiary nozzles were investigated for heated and unheated high-subsonic conditions. Centerline velocity decay rates for the single-, dual- and three-stream axisymmetric jets compared well when axial distance was normalized by an equivalent diameter based on the nozzle system total exit area. The tertiary stream had a greater impact on the mean axial velocity for the small bypass-to-core area ratio nozzles than for large bypass-to-core area ratio nozzles. Normalized turbulence intensities were similar for the single-, dual-, and three-stream unheated jets due to the small difference (10 percent) in the core and bypass velocities for the dual-stream jets and the low tertiary velocity (50 percent of the core stream) for the three-stream jets. For heated jet conditions where the bypass velocity was 65 percent of the core velocity, additional regions of high turbulence intensity occurred near the plug tip which were not present for the unheated jets. Offsetting the tertiary stream moved the peak turbulence intensity levels upstream relative to those for all axisymmetric jets investigated.
Document ID
Acquisition Source
Glenn Research Center
Document Type
Technical Memorandum (TM)
Henderson, Brenda S.
(NASA Glenn Research Center Cleveland, OH United States)
Wernet, Mark P.
(NASA Glenn Research Center Cleveland, OH United States)
Date Acquired
August 2, 2016
Publication Date
July 1, 2016
Subject Category
Fluid Mechanics And Thermodynamics
Report/Patent Number
Meeting Information
Meeting: SciTech 2016
Location: San Diego, CA
Country: United States
Start Date: January 4, 2016
End Date: January 8, 2016
Sponsors: American Inst. of Aeronautics and Astronautics
Funding Number(s)
WBS: WBS 110076.
Distribution Limits
Work of the US Gov. Public Use Permitted.
Three-Stream Jets
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