Insert for shear layers and vortical structures comprises densely packed flexible smooth hair-like structures of textiles or synthetic fibers of specified diameter length and structural density.

摘要

The hair-like structures (2a,2b) have diameter (d) between (1-100) . v/utau , in which (v) denotes the kinetic viscosity of the fluid and (utau ) the wall friction velocity. The hair length L(a) amounts to Ldelta of 10% to 200% in which (delta ) is the thickness of the boundary layer in the turbulent after flow (b), in the mixing layers and jets this being several times the dimensions of the vortices forming without this arrangement. The hair structural density (s/d) lies between 1 and 10 with structural interval (s) and diameter (d). The hairs come in rectangular section with height to width side ratio of 3 to 1, the hairs for use in fluid or gaseous flows e.g. in flowed carbody parts, specifically in tubes. Hairs can be fitted in tube expansions or diffusers with supercritical expansion angle.