Active Flow Control for Wing Performance Enhancement

This technology is an enhanced performance version of an airplane fluidic fence using active flow controls in the wing surface. The invention is applicable to wings of all shapes including helicopter rotors, propellers, wind turbines, fans and compressor blades.

Background:
To alleviate problems at high lift conditions, some designers have added chord-wise fences on highly swept wings. They can be seen, for example, in the MiG 15. These fences serve to interrupt the span-wise flow and alleviate the tip separation problem as well as help to redirect the flow in the fore-aft direction, which increases lift. However at cruise they are unneeded and thus produce only drag, both from the point of view of added surface area (skin friction) and from the added vorticity generated at the intersection of the boundary layers of the wing and the fence, which represents an energy loss.

Applications:

• Straight-winged airplanes
• Swept back wings
• Modern airplane wings

Advantages:

• Reduces the span-wise velocity component
• Enables the airplane designer to increase the sweep back of the wings to 45 degrees and beyond
• Avoids wing tip stall
• Could increase substantially if no major drag penalty with the increase of sweep back the critical Mach number of the airplane