Abstract: Systems and methods for secondary suctioning for an aerodynamic body are presented. A primary surface is configured along a leading edge of an aerodynamic body, and at least one secondary suction device comprising an elongated shape is configured at least a first distance from the primary surface. A non-suction surface is configured between the primary surface and the at least one secondary suction device.

Abstract: Systems and methods for secondary suctioning for an aerodynamic body are presented. A primary surface is configured along a leading edge of an aerodynamic body, and at least one secondary suction device comprising an elongated shape is configured at least a first distance from the primary surface. A non-suction surface is configured between the primary surface and the at least one secondary suction device.

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.

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.

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.

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.

Abstract: A method and apparatus using localized heating to encourage laminar flow along an airfoil exterior surface. The airfoil includes a leading edge (24), a controlled surface (18), and an uncontrolled surface (20). The present invention localized heating system (38) includes a heat source (40) located within the airfoil and connected to the leading edge (24), and a heat sink (42) positioned aft of the heat source (40) and arranged to transfer heat from the airfoil controlled surface (18) to the uncontrolled surface (20). The heat sink (42) preferably expels heat along uncontrolled surface adjacent to turbulent air flow. In one preferred embodiment as applied to a generally circular aircraft engine nacelle (12), the heat source (40) is an electro-thermal heat source (44) having a high resistance wire embedded in a composite material leading edge structure (50), and the heat sink (42) is a heat pipe (52) having a wicking material (58) and a vaporizing agent (60).