The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 30, 1985
Filed:
Feb. 14, 1985
Brian Barry, Duffield, GB;
Christopher Freeman, Farnsfield, GB;
Rolls-Royce Limited, London, GB;
Abstract
In order to combat flutter in rotor blades rotating within a duct bounded by a duct wall, the duct wall incorporates cavities tuned for resonance to a known flutter frequency. The cavities, which may comprise tubes immediately underlying a facing sheet of the duct wall, are arrayed around the circumference of the duct wall and communicate with the duct through openings in the duct wall near the tips of the blades. Flutter energy from the blades is transferred directly to the cavities by pressure waves and produces resonance in the cavities so that the flutter is damped aerodynamically. The invention is applicable to fans in turbofan engines.