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:
Apr. 14, 2009
Filed:
Mar. 02, 2005
Marco Rose, Freiberg, DE;
Fredi Holste, Berlin, DE;
Frank Arnold, Berlin, DE;
Alastair D Moore, Derby, GB;
Marco Rose, Freiberg, DE;
Fredi Holste, Berlin, DE;
Frank Arnold, Berlin, DE;
Alastair D Moore, Derby, GB;
Roll-Royce Deutschland Ltd & Co KG, Blankenfelde-Mahlow, DE;
Abstract
A device for simulating sound produced by certain equipment, for example a rotor-stator arrangement of a turbomachine, or for generation of opposing sound fields for active sound control, including active sound reduction and active sound amplification, comprises flow obstacles () provided in a flow duct () flown by a fluid at which vortices () are shed at a certain frequency depending on the shape and size of the flow obstacles and the velocity of flow. The quantity and spatial arrangement of the flow obstacles is selected such that a periodically spatially and temporally changing pressure field for the excitation of a sound field () of a certain modal content is produced by the entirety of the vortices shed. This sound field reacts synchronizingly on the vortex shedding. The resonant circuit so formed, whose vortex shedding frequency is in the range of the resonant frequency of the sound field to be excited, is the sound source.