Aeronautics and astronautics – Aircraft sustentation – Sustaining airfoils
Reexamination Certificate
2011-06-07
2011-06-07
Dinh, Tien (Department: 3644)
Aeronautics and astronautics
Aircraft sustentation
Sustaining airfoils
C244S200100, C244S130000, C244S133000
Reexamination Certificate
active
07954767
ABSTRACT:
Laminar flow surfaces with selected roughness distributions, and associated methods are disclosed. A representative method for designing an airfoil includes selecting a parameter that includes a flow behavior distribution and/or a surface shape for an airflow surface. Based at least in part on the selected parameter, the method can include (a) selecting a target roughness value and determining a chordwise location forward of which surface roughness is at or below the target roughness value and/or (b) selecting a target chordwise location and determining a roughness value for a region forward of the chordwise location, with the surface roughness at or below the roughness value. In particular embodiments, a percentage of a local chord length of the airfoil over which the roughness is below a target value decreases in a spanwise direction. In another embodiment, the roughness at a particular spanwise location can increase over at least three values, continuously, in a step manner, or otherwise.
REFERENCES:
patent: 4575030 (1986-03-01), Gratzer
patent: 4813631 (1989-03-01), Gratzer
patent: 6027078 (2000-02-01), Crouch et al.
patent: 6834830 (2004-12-01), Fujino
patent: 6969029 (2005-11-01), Crouch et al.
patent: 7093792 (2006-08-01), Fujino
patent: 2008/0061192 (2008-03-01), Sullivan
Crouch, J.D. et al “Variable N-Factor Method for Transition Prediction in Three-Dimensional Boundary Layers”, pp. 211-216, AIAA Journal, vol. 38, No. 2. February.
Crouch, J.D. et al “Receptivity of Three-Dimensional Boundary Layers”, 10 pgs, AIAA 93-0074, 31stAerospace Sciences Meeting & Exhibit, Jan. 1993, Reno, NV.
Radeztsky, Jr. R.H. et al., “Effect of Mircon Sized Roughness on Transition in Swept-Wing Flows”, 14 pgs, AIAA 93-0076, 31stAerospace Sciences Meeting & Exhibit, Jan. 1993, Reno, NV.
Schrauf, G., “Status and perspectives of laminar flow”, pp. 639-644, The Aeronautical Journal, vol. 109, No. 1102, Dec. 2005.
Likhanskii, A.V. et al., “Optimization of Dielectric Barrier Discharge Plasma Actuators Driven by Repetitive Nanosecond Pulses”, AIAA 2007-633, 13 pgs, AIAA Aerospace Meeting and Exhibit, Jan. 2007, Reno, NV.
Crouch Jeffrey D.
Ng Lian L.
Sutanto Mary I.
Benedik Justin
Dinh Tien
The Boeing Company
Tung & Associates
LandOfFree
Laminar flow surfaces with selected roughness distributions,... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Laminar flow surfaces with selected roughness distributions,..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Laminar flow surfaces with selected roughness distributions,... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2675741