Aeronautics and astronautics – Aircraft sustentation – Sustaining airfoils
Reexamination Certificate
2007-04-25
2010-12-14
Collins, Timothy D (Department: 3644)
Aeronautics and astronautics
Aircraft sustentation
Sustaining airfoils
C244S133000, C244S130000, C244S200100
Reexamination Certificate
active
07850126
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.
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Crouch Jeffrey D.
Ng Lian L.
Sutanto Mary I.
Benedik Justin
Collins Timothy D
Perkins Coie LLP
The Boeing Company
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