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:
May. 01, 2007
Filed:
Nov. 16, 2001
Hiroshi Kobayashi, Tokyo, JP;
Hiroshi Kobayashi, Tokyo, JP;
National Aerospace Laboratory of Japan, Chofu-shi, JP;
Abstract
A spaceconstituted by a sound absorption panel sectionand active sound absorption control system sectionbetween the inner and outer walls of a nacelle forming an engine intake/exhaust duct is utilized as an acoustic resonance field and as a sound absorption field by sticking a porous sound absorption materialonto the inside wall surface of the space. The panel sectiondefines a sound absorption space by means of surface platemade of a perforated plate and wire mesh materials plate, panel construction side plateand back sheet platehaving porous sound absorption material stuck thereon; and a movement-controlled reflective plate, that is capable of movement/rotation control with respect to said perforated plate, is provided within this sound absorption space. Movement of the reflective plateis controlled utilizing the adaptive feed forward control method by means of the output from an active sound absorption control system section