Vortex control for rotor blade devices

US7467921B2 · kind B2 · utility

Assignee

• The United States of America as represented by the Administrator of the National Aeronautics and Space Administration · US

Inventor

• David Greenblatt · Newport News, US

Key dates

• Filing date: Sep 22, 2005
• Grant date: Dec 23, 2008
• Expiry date: Jun 14, 2027

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B64C27/463
• WIPO field: Transport
• WIPO sector: Mechanical engineering

Abstract

To control vortices originating at the tips of a rotor's blades rotating through the air at a revolution frequency f, separation control device(s) are actuated to periodically introduce perturbations into the airflow moving over the blades. The periodic introduction of perturbations is controlled in accordance with a periodic modulating frequency of introduction f0 while the frequency of the perturbations so-introduced is designated as fe. Vortex control is achieved when the periodic modulating frequency of introduction f0 satisfies the relationshipnf≦f0≦fewhere n is the number of blades.