Oscillating air jets for implementing blade variable twist, enhancing engine and blade efficiency, and reducing drag, vibration, download and ir signature
Number of patents in Portfolio can not be more than 2000
United States of America Patent
Stats
-
Apr 8, 2003
Issued Date -
N/A
app pub date -
Nov 24, 1998
filing date -
Jun 5, 1997
priority date (Note) -
In Force
status (Latency Note)
Importance
Abstract
A porous surface on an aircraft structure driven with oscillating positive and negative pressures is used as an active control device for attenuating negative aerodynamic interactions. The porous surfaces can be driven with positive and negative pressures either continuously or when predetermined flight conditions are present. The porous surfaces can be used on rotor blades to reduce BVI noise in descent flight conditions. The porous surfaces can be configured on rotor blades for affecting blade variable twist in accordance with various flight conditions, and can further be incorporated for reducing rotor hub vibrations as well. Porous surfaces placed on aerodynamic surfaces below the rotor blades of a tiltrotor aircraft can attenuate or eliminate download and fountain flow conditions. When placed on the trailing edges of a tip jet-exhaust driven rotor blade, the porous surfaces of the present invention can supplement the tip jet momentum of the exhaust to thereby reduce an amount of exhaust needed to drive the rotor blade.
First Claim
Other Claims data not available
Family
International Classification(s)
Cited Art Landscape
Patent Citation Ranking
- 38 Citation Count
- B64C Class
- 95.51 % this patent is cited more than
- 22 Age