초록 ▼

Turbulence is controlled in boundary layer or wall-bounded fluid flow fields having a turbulent wall region which under natural conditions, has an average system of roll pairs or streaks adjacent the surface, and extending in the direction of flow, by locally introducing into the turbulent wall regi

Turbulence is controlled in boundary layer or wall-bounded fluid flow fields having a turbulent wall region which under natural conditions, has an average system of roll pairs or streaks adjacent the surface, and extending in the direction of flow, by locally introducing into the turbulent wall region, by passive means, a disturbance that enhances or inhibits the roll pairs thereby locally increasing or decreasing the turbulence in the flow field.

대표청구항 ▼

[ What is claimed is:] [1.] Apparatus for decreasing turbulent drag in a turbulent wall region of a fluid flow field adjacent the surface of a wall, wherein said turbulent wall region is characterized by a system of roll pairs or steaks adjacent said surface, said roll pairs or streaks having a diam

[ What is claimed is:] [1.] Apparatus for decreasing turbulent drag in a turbulent wall region of a fluid flow field adjacent the surface of a wall, wherein said turbulent wall region is characterized by a system of roll pairs or steaks adjacent said surface, said roll pairs or streaks having a diameter functionally related to the strength of the flow, said apparatus including a two-dimensional array of protrusions on, or cavities in, said surface for introducing into said wall region a passive disturbance that inhibits the creation of said roll pairs, wherein said protrusions, or cavities, are arranged in successive columns perpendicular to the direction of fluid flow, the protrusions, or cavities, of a succeeding row being staggered relative to the protrusions, or cavities of a preceding row.