Method and apparatus for influencing a laminar turbulent boundary layer transition on bodies in flow

Patent 4989810 Issued on February 5, 1991. Estimated Expiration Date:

November 17, 2008. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Abstract Claims Description Full Text

Patent References

3161385

3362663

3467348

Low drag surface construction
Patent #: 4693201
Issued on: 09/15/1987
Inventor: Williams , et al.

Ultrasonic drag reduction and lift increase
Patent #: 4741498
Issued on: 05/03/1988
Inventor: Gerhardt

Surface, exhibiting reduced flow resistance, of a body over which turbulent flow takes place
Patent #: 4753401
Issued on: 06/28/1988
Inventor: Bechert

System for boundary layer control through pulsed heating of a strip heater
Patent #: 4786020
Issued on: 11/22/1988
Inventor: Franke , et al.

Control of laminar flow in fluids by means of acoustic energy
Patent #: 4802642
Issued on: 02/07/1989
Inventor: Mangiarotty

Laminar flow control airfoil
Patent #: 4813631
Issued on: 03/21/1989
Inventor: Gratzer

Vertical take-off and landing aircraft Patent #: 4848701
Issued on: 07/18/1989
Inventor: Belloso

Inventors

Assignee

Deutsche Forschungs- und Versuchsanstalt fur Luft- Und Raumfahrt e.V.

Application

No. 272627 filed on 11/17/1988

US Classes:

244/208And suction

Examiners

Primary: Jordan, Charles T.
Assistant: Wendtland, Richard W.

Attorney, Agent or Firm

Thomas & Kerr

Foreign Patent References

0264144 EP. 04/12/1988
210498 DE. 10/12/1983
228939 DE. 11/12/1983
3316392 DE. 11/12/1984
320481 DE. 12/12/1984
3738366 DE. 05/12/1989
2188397 GB. 09/12/1987

International Classes

F15D 001/12
H04R 009/06

Foreign Application Priority Data

1987-11-12 DE

Abstract

A method and an apparatus for influencing a laminar-turbulent boundary layer transition on bodies in flow is indicated. The disturbances are in this case introduced into the boundary layer in an unsteady manner. The disturbances are induced by blowing-out and sucking-off and/or by oscillations of the surface and/or by sound pressure.

Other References

DFVLR-AIAA-83-1673 Problems Associated with Artificial Boundry Layer Tranion, by H. U. Meier, H. P. Kreplin
Control of Laminar-Instability Waves Using a New Technique, by H. W. Liepmann, G. L. Brown and D. M. Nosenchuck
AIAA-89-1005 Boundary Layer Transition Controlled by Flush Mounted Electro Acoustic Generators, by H. U. Meier, DNW & Zhou Ming de Na