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Entrainment characteristics of unsteady subsonic jetsThe effectiveness of jet unsteadiness in enhancing flow entrainment was assessed. It was conducted that entrainment depends on the type and amount of jet unsteadiness. Apparently, the mere introduction of jet unsteadiness by small sinusoidal flow angle variations is insufficient to enhance entrainment but, it should be noted that the results were obtained at measuring stations which are all many nozzle widths downstream of the jet nozzle. Thus, no fully conclusive statement can be made at this time about the entrainment close to the nozzle. The high entrainment of the fluidically oscillated jet was caused by the high-frequency content of this square wave type of oscillation but more detailed measurements are clearly needed, in particular for the fluidically oscillated and the pulsed jets. Practical ejector application requires the proper trade-off between entrainment and primary nozzle thrust efficiency.
Document ID
19800001885
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Platzer, M. F.
(Naval Postgraduate School Monterey, CA, United States)
Simmons, J. M.
(Queensland Univ. Brisbane, Australia)
Bremhorst, K.
(Queensland Univ. Brisbane, Australia)
Date Acquired
August 10, 2013
Publication Date
September 1, 1979
Publication Information
Publication: NASA. Ames Res. Center Workshop on Thrust Augmenting Ejectors
Subject Category
Aerodynamics
Accession Number
80N10124
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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