Abstract: A thrust augmentation technique wherein a primary gas stream is directionally switched at a high rate to produce flow discontinuities in the interest of increasing efficiency. Apparatus in accordance with the invention includes a fluidic switch, particularly a controlled expansion thrust vector control nozzle, which delivers a pulsating primary gas stream to an eductor or lift surface.

Abstract: Fluidic switches characterized by a first divergent region immediately downstream of a nozzle throat and a second downstream region of reduced divergence which will be contacted by a deflected jet. The switches of the present invention include control ports which are normally open to the ambient atmosphere, the ports being located at or near the free stream separation point, and the transition from the first divergent section to the second section is located at or near the attached stream separation point. The switches of the present invention may assume a circular cross-section and when so doing will be provided with a plurality of ribs on the internal surface for preventing circumferential flow about a deflected jet.