Method and apparatus for delaying the separation of flow from a solid surface
OwnerIsrael Wygnanskiinventor
Life of this patent
Estimating the term…
Abstract
An active perturbation-producing element on the solid surface is driven to induce oscillations in the boundary layer of the fluid stream about an axis substantially perpendicular to the solid surface, to enhance the mixing of the boundary layer in the fluid stream. The method is particularly applicable for increasing the lift of a wing, but may also be used for increasing the divergence angle of a diffuser.
Claims20
An active method of delaying the separation of the flow from a solid surface to higher angles of divergence or incidence characterized in that a perturbation-producing element on the solid surface is driven by an active drive at a predetermined frequency dependent on the air stream velocity but independent of the fluctuations existing locally in the flow, to induce travelling oscillations in the boundary layer of the fluid stream substantially perpendicular to the solid surface to enhance mixing of the boundary layer with the fluid stream outside the boundary layer.
Apparatus including a solid surface disposed within a fluid stream, characterized in that said apparatus includes a perturbation-producing element in the vicinity of the leading edge of said solid surface, and active drive means for driving said perturbation-producing element at a predetermined frequency, dependent on the air stream velocity but independent of the fluctuations existing locally in the flow, to induce travelling oscillations of the boundary layer of the fluid stream substantially perpendicular to said solid surface to enhance mixing of the boundary layer of the fluid stream, and thereby to delay the separation of said boundary layer from the solid surface.
Dependencies are inferred from the claim text.