| 摘要 |
<p>The present invention is a method for controlling sonic under expanded jets issued from aircraft gas turbine engine nozzle, more specifically the present invention discloses a perforation more particularly a plurality of perforated tab more particularly straight, circular, elliptical and square perforated tab and a slanted perforated with perforation angle 10°, 20° and 30° tab to provide enhanced mixing and further provides jet noise reduction by weakening shock cells. Perforated tab sheds vortices of non uniform size not only from the edges but also from the perforation. The vortices shed from the perforation are dictated by type of perforation or geometry of perforation. The present invention helps to reduce potential core length by shear layer interaction and entraining more mass of air from the ambient atmosphere into the jet core thus reducing noise from aircraft gas turbine engines. Moreover, the slanted perforated tabs are at angles to intersect at any point in the potential core of the jet. The intersection point within the potential core length provides rapid mixing process with the ambient air. Further, the geometry of the perforation has greater influence on controlling high speed jet.</p> |
