Abstract: The present invention provides an apparatus and system for controlling turbulence generated by medium passing about a bluff body disposed on a generally planar flow surface. An aft fairing, of a predetermined shape, is disposed on the flow surface in close proximity to the outbound section of the bluff body and a curved vortex fence, of a predetermined shape, is disposed on the flow surface near the front section of the bluff body with a predetermined gap between the vortex fence and the bluff body. In practice, the flow surface is propelled in a forward direction to develop medium flow from the front side of the bluff body to the outboard side of the bluff body. As the medium flows about the bluff body, the curved vortex fence re-directs the flow surface boundary layer in such a manner as to stabilize and strengthen the horse-shoe vortex by trapping it within the gap. The aft fairing stabilizes the downstream-directed legs of the horse-shoe vortex art of the bluff body.

Abstract: An airplane has a plurality of airfoils with leading edges. A partition and a nose cap are located at a forward surface of the airfoil, creating upper and lower cavities. The nose cap may be positioned in an extended position or a retracted position. The nose cap is retracted when the airplane reaches supersonic speed. At supersonic speed, a shock wave forms on the leading edge of the airfoil. A compression zone forms between the shock wave and the leading edge, diverting the heat and pressure of the shock wave away from the airfoil. Downstream from the compressed zone, pressure wakes form along the airfoil and cool the airfoil. At subsonic speed, the nose cap is extended to achieve optimal airfoil efficiency. Forward or rearward gaps may be opened between the nose cap and the main body portion of the airfoil to allow airflow from the lower cavity below the partition to the upper cavity above the partition to selectively increase or decrease lift on the airfoil.