Entrainment characteristics of unsteady subsonic jets. [for V/STOL aircraft]
MetadataShow full item record
The 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.
SEE ParentDocumentRecord|Ntt=19800001868 "NASA. Ames Res. Center Workshop on Thrust Augmenting Ejectors"; p. p 311-324
RightsThis publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.
Showing items related by title, author, creator and subject.
McClellan, Thomas Robert (Monterey, California. Naval Postgraduate School, 1982);An experimental investigation has been conducted to evaluate the entrainment characteristics of a thrust augmenting ejector, with a small, oscillating airfoil inserted in the potential core of the primary jet. Velocity ...
Andreou, Loukas. (Monterey, California: Naval Postgraduate School, 1999);A turbo-ramjet engine configuration has possible applications in missiles or Uninhabited Aerial Vehicle's (UAV's). In order to study possible configurations, a Sophia J450 turbojet engine was used, with varying shroud ...
Platzer, Maximilian F.; Simmons, John M. (The United States of America as represented by the Secretary of the Navy, Washington, DC (US), 1983);To achieve rapid mixing between a jet flow and its surrounding medium a vane is mounted in the jet downstream of the jet nozzle exit. The vane is oscillated in either pitch or plunge by an appropriate excitation mechanism ...