Patent ID: 6186445
Filing Date: 2001-02-13
Classification: B64C,F15D,Y02T

Abstract:
A method for mitigating the effect of the necklace vortex on an obstacle projecting above a floor plane, the obstacle having a windward side facing the direction of a flowfield and a thickness defining at least one free space region beyond the thickness, the method comprising:providing a winged device comprising a lifting structure, the lifting structure having a bottom surface and a spanwise width terminating in at least one tip and being configured to induce a positive lift in a flowfield contacting the lifting structure; anddisposing the winged device a distance in front of the windward side of the obstacle relative to the flowfield to define a placement distance with the bottom surface above the floor plane and the spanwise width of the lifting structure aligned along the thickness of the obstacle so that the at least one tip is directed toward the at least one free end, wherein when the flowfield flows towards the obstacle, the flowfield contacts the lifting structure which directs the flowfield toward the at least one tip, the spanwise width and the placement distance being sufficiently large that the winged device spreads the flowfield away from the center of the obstacle to the at least one free space region to thereby mitigate the effect of the necklace vortex.