A novel mechanism for reducing boundary layer friction and inhibiting the effects of uncontrolled fluid turbulence and turbulent layer separation, thus reducing the body drag, kinetic energy losses and lowering engine and pump fuel consumption is proposed. It steps on the type of turbulence observed in the so-called in fluid dynamics drag crisis. Plurality of device shapes and plurality of devices producing the wanted pure form of even plurality of counter-rotating vortices extending into the flow, i.e. tubes, are presented and discussed in detail, contrasting with the prior art. Configurations of multiple devices for the purposes of drag and fuel reduction, including their simulations and experimental results are put forward. Additional embodiments of the resulting tubes disclose use on aircraft or vessel control surfaces as stall inhibitors, use in wind turbines as dynamic range extenders, as well as use in turbines in efficient cooling mechanisms.

A component stage for a turbomachine includes a component section. The component section includes a flowpath surface at least partially exposed to a core air flowpath defined by the turbomachine, when the component stage is installed in the turbomachine. The component further includes a plurality of sequentially arranged riblets on the flowpath surface, the plurality of sequentially arranged riblets customized for an anticipated location of the flowpath surface within the turbomachine by defining one or both of a non-uniform geometry or a non-uniform spacing.

A structural component for a vehicle has a surface with a riblet structure. The riblet structure includes a plurality of grooves, including a first groove having a first longitudinal section forming a first angle with a main longitudinal direction of the structural component. The first angle is larger than 0 and the main longitudinal direction corresponds to a flow direction of a fluid along the surface of the structural component.

Provided are aerodynamic articles and related methods that use an aerodynamic body with a microstructured surface thereon. The microstructured surface has a plurality of parallel primary ridges defining major capillary channels, and optionally a plurality of parallel secondary ridges having a height less than that of the primary ridges and extending between and generally parallel to the primary ridges. The optional secondary ridges at least partially define two or more minor capillary channels within each major capillary channel. The aerodynamic surface provides reduced drag and is capable providing a high degree of friction against shoe surfaces under oil and water contaminated conditions.

A method of applying a riblet structure coating on the internal surface of a pipe includes coating the internal surface of a pipe with a resin layer and applying a cavity mold having a reverse riblet pattern structure to the coated internal surface of the pipe. A flexible air bag is inserted into the interior of the pipe and charged with air to hold the mold against the coated internal surface of the pipe. The air bag may be charged with air for a sufficient amount of time to allow the coating to cure in the riblet shape of the mold. Afterwards, the air bag and the mold are removed from the pipe to yield a pipe coated with an internal riblet structure.

Part comprising a wall which comprises a first zone (541), a first zone (541) and the second zone (542), a network of riblets being formed on the first zone (541), the second zone (542) and also on the transition zone (54t) so as to reduce the drag of the part when a flow of air flows along said wall; the height, the width and the spacing of the riblets formed on the transition zone (54t) changing along said transition zone (54t) so as to pass from the height, width and spacing of the riblets formed on the first zone at a first end of the transition zone to the height, width and spacing of the riblets formed on the second zone (542) at a second end of the transition zone (54t), the transition zone (54t) comprising a central portion on which the riblets comprise on one hand the height and the width that are respectively equal to the height and width of the riblets on the first zone (541), and on the other hand a spacing equal to the spacing of the riblets of the second zone (542).

A surface-processed structure includes a plurality of blocks that are three-dimensional objects arranged on a target surface. The plurality of blocks are spaced apart from each other and are arranged side by side in a second direction. Each of the plurality of blocks includes a top face including a plurality of fine grooves. The plurality of fine grooves are spaced apart from each other, are arranged side by side in the second direction, and extend from upstream to downstream in a first direction. A width of each of the plurality of fine grooves in the second direction is less than a width of a block clearance in the second direction. Both end portions of the top face in the second direction are located above bottoms of the plurality of fine grooves in a cross section of the block extending along a plane perpendicular to the first direction.

A surface-processed structure includes a blocks arranged side by side in a first direction parallel to a target surface. The blocks are three-dimensional objects arranged on the target surface. Each of the blocks includes an inclined surface extending from upstream to downstream in the first direction with a distance from the target surface gradually increasing. The inclined surfaces of the blocks are arranged side by side on one line extending in the first direction. Each of the blocks includes a fine grooves provided on the inclined surface. The fine grooves are spaced apart from each other, are arranged side by side in a second direction orthogonal to the first direction, and extend from upstream to downstream in the first direction. The fine grooves extend at a constant depth from an upstream end portion to a downstream end portion of the inclined surface in the first direction.

The present invention relates to structured, gas-holding surfaces for improving the friction-reducing properties of gas layers held under a liquid and for the simultaneous suppression of turbulence. The present invention furthermore relates to a device comprising this structured, gas-holding surface and to the use of this structured, gas-holding surface.

A multilayer construction for aerodynamic riblets includes a first layer composed of a material with protuberances, the first layer material exhibiting a first characteristic having long-term durability and a second layer composed of a material, exhibiting a second characteristic with capability for adherence to a surface.