Jet Vectoring Through Periodic Excitation
The Invention Jet Vectoring through Periodic Excitation enables the control of the direction of a jet without any moving parts. This method has many advantages, the main ones being the enhanced ability to quickly and effectively control the jet in several axis and the potential weight reduction compared to a mechanical thrust vectoring system. Periodic Excitation enables the change of aerodynamic forces and moments with exceptional bandwidth, without generating prohibitive inertial loads on the jet’s airframe.The Need Jet Vectoring though Periodic Excitation makes use of Active Flow Control methods in order to control the movement of fluid stream or solid body. A short, wide-angle diffuser is attached at the jet exit and periodic excitation is introduced at the juncture between the jet exit and the diffuser inlet. The introduction of periodic excitation at the location of the boundary layer separation enhances the mixing of the high momentum fluid away from the surface and the low momentum fluid near the surface.
Periodic excitation is more efficient than steady suction and is two orders of magnitude more efficient at controlling separation than steady blowing. Vectoring is achieved by applying the excitation over a fraction of the circumference of the circular jet, enhancing its spreading rate on the excited side and its tendency to reattach to that side. The turbulent jet responds quickly (10-20 msec) to step changes in the level of the excitation input. The method also allows for jet rotation. Potential Applications Jet vectoring can be a substantial advancement in the fields of aerospace, transportation and chemical industries. This can be applied to various applications, such as miniature air-vehicles, rectangular jets, and more. Control of turbulent jets is extremely important for aerospace and mechanical applications.
References Pack, L.G. and Seifert, A., “Periodic Excitation for Jet Vectoring and Enhanced Spreading”, (AIAA paper 99-0672), J. Aircraft, vol. 38, no. 3, pp. 486-495. (2001)
Avihar, E., Shemesh, N., Pack, L.G. and Seifert, A., “Rotation of a Rectangular Jet by Periodic Excitation”, J. Aircraft, 40 (1): pp. 217-219 Jan-Feb 2003.
Patent Granted US, IL, EP Tech Transfer Officer Mr. Larry Loev Office: +972-3-6406544 Fax: +972-3-6406675 Mail: [email protected]
Inventor(s): Avraham Seifert
Type of Offer: Licensing
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