PASSIVE DRAG MODIFICATION SYSTEM

摘要

The present invention is directed to a micro-array surface that provides for drag reduction. An aerodynamic or hydrodynamic wall surface that is configured to modify a fluid boundary layer on the surface is provided. The wall surface has a plurality of cavities defined therein the surface. In various examples, the interaction of the cavities with a flow of fluid relative to the wall surface is configured to form a plurality of stable, embedded cavity vortices such that a partial slip condition is produced over the wall surface.

主权项

1. An aerodynamic or hydrodynamic wall surface configured to reduce frictional drag between the wall surface and a fluid flowing relative to the wall surface, comprising:
a plurality of roughness elements disposed on and extending therefrom the wall surface, wherein each roughness element has a front, upstream surface and an opposing rear, downstream surface, wherein the plurality of roughness elements are positioned substantially transverse to the flow of fluid across the wall surface, wherein the plurality of roughness elements are positioned to define at least one embedded cavity therebetween successive roughness elements, wherein the flow of fluid relative to the wall surface forms at least one cavity vortex rotating therein each embedded cavity, wherein at a predetermined fluid flow rate relative to the wall surface, at least a portion of the at least one cavity vortex rotates outside of the cavity, and wherein the at least one cavity vortex reduces friction between the fluid and the wall surface.