Method and apparatus for mitigating junction flows

A method for mitigating the effect of the necklace vortex on an obstacle projecting above a floor plane, the obstacle having a windward side and a thickness defining at least one free space region beyond the thickness, the method comprising:

• providing a winged device comprising at least one tip and a lifting structure, the lifting structure configured to induce a positive lift in a flowfield contacting the structure and including a bottom surface;
• and
• disposing the winged device adjacent the windward side of the obstacle and with the bottom surface above the floor plane so that when the flowfield flows towards the obstacle, the flowfield contacts the lifting structure which directs the flowfield away from the center of the obstacle and toward the at least one tip and the at least one free space region, in which the lifting structure has a trailing edge disposed facing the obstacle with at least part of the trailing edge touching the floor plane.

An apparatus for mitigating the effect of the necklace vortex on a foundational member of a bridge or pier, the foundational member having a thickness defining at least one free space region beyond the thickness, the apparatus comprising:

• a winged device comprising at least one tip and a lifting structure, the lifting structure configured to induce a positive lift in a flowfield contacting the structure and having a spanwise width and a bottom surface, wherein the winged device is adapted so that when it is disposed adjacent the windward side of the foundational member with its bottom surface above the floor plane, a flowfield upon contacting the winged device is directed away from the center of the foundational member, downwardly toward the floor plane, and along the spanwise width toward the at least one tip which induces velocity in the flowfield and directs the flowfield away from the center of the foundational member to mitigate the effect of the necklace vortex.

An apparatus for mitigating the effect of the necklace vortex on an obstacle, the obstacle having a thickness defining at least one free space region beyond the thickness, the apparatus comprising:

• 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, wherein when the winged device is disposed adjacent the windward side of the obstacle with its bottom surface above the floor plane, a flowfield upon contacting the winged device is directed away from the center of the obstacle, downwardly toward the floor plane, and toward the at least one tip which induces velocity in the flowfield,
• wherein the spanwise width of the winged device is so dimensioned relative to the thickness of the obstacle that the flowfield is directed outward along the spanwise width and away from the center of the obstacle to the at least one free space region to thereby mitigate the effect of the necklace vortex.