According to one embodiment, a method of dispersing nanoparticles into a destination material includes providing a plurality of nanoparticles suspended in a carrier, adding a solvent to the plurality of nanoparticles suspended in a carrier, removing at least some of the carrier to yield the plurality of nanoparticles suspended in the solvent, mixing the nanoparticles suspended in the solvent with a destination material, and removing at least some of the solvent from the mixture of nanoparticles suspended in the solvent and the destination material.

Multilayer riblet applique and methods of producing the same are described herein. One disclosed example method includes applying a first high elongation polymer material to a web tool, where the web tool is to be provided from a first roll, and heating, via a first heating process, the first high elongation polymer material. The disclosed example method also includes applying a second high elongation polymer material to the first high elongation polymer material, and heating, via a second heating process, the second high elongation polymer material. The disclosed example method also includes applying, via a laminating roller, a support layer to the second high elongation polymer material.

Airfoil and hydrofoils systems with structures having a surface texture defined by fractal geometries are described. Raised portions or fractal bumps can be included on the surfaces, forming a surface texture. The surface textures can be defined by two-dimensional fractal shapes, partial two-dimensional fractal shapes, non-contiguous fractal shapes, three-dimensional fractal objects, and partial three-dimensional fractal objects. The surfaces can include indents having fractal geometries. The indents can have varying depths and can be bordered by other indents, or bumps, or smooth portions of the airfoil or hydrofoil structure. The fractal surface textures can reduce vortices inherent from airfoil and hydrofoil structures. The roughness and distribution of the fractal surface textures reduce the vortices, improving laminar flow characteristics and at the same time reducing drag. The systems are passive and do not require applied power.

An air inlet for a flight vehicle engine includes at least one fin, at least partially upstream of a throat of the engine. The fin protrudes into a flow channel, extending beyond a boundary layer into the main airstream in the inlet. The fin causes mixing in the flow, bringing high-momentum flow into areas of the flow channel containing low-momentum flow by aggregating the boundary layer and causing it to lift from the surface. The fin may have a width and/or height that varies along its length in the flow direction, which may allow it to shape the flow around it in predictable ways, without resulting in excessive drag.

This relates to the field of aerohydrodynamics and can be used on wings and control surfaces of aircraft, controlled spoilers of sports cars, all-movable masts and sails of sailing yachts and sailboards, as well as on blades and vanes of various bladed machines. An aerohydrodynamic surface includes an array of vortex generators and a main part. The main part comprises two sides mating with each other to form a leading and a trailing edges. The array of vortex generators includes elevations with crescent-shaped working edges located near the leading edge. The elevations and the working edges are configured to generate counter-rotating vortex structures. An array of vortex generators and a method of mounting the same onto the aerohydrodynamic surface are also described. The invention makes it possible to improve the properties of the aerohydrodynamic surfaces at high angles of attack.

In one embodiment, a method for reducing drag includes forming a smooth surface on a first portion of a physical object. The method also includes forming periodic riblets on a second portion of the physical object. The second portion of the physical object is adjacent to the first portion of the physical object. Each riblet of the periodic riblets of the second portion of the physical object is depressed below a plane of the smooth surface of the first portion of the physical object. The method further includes generating a flow over the periodic riblets of the second portion of the physical object and over the smooth surface of the first portion of the physical object. A length of each riblet of the periodic riblets runs parallel to a direction of the flow.

An aerodynamic device for enhancing lift and reducing drag on a body, comprising a plurality of raised members, each having a symmetric profile and including a central portion having an elongated profile, and first and second outer portions having elongated profiles and arranged substantially parallel to and on opposing sides of the central portion, wherein the plurality of raised members are situated adjacent one another to form a continuous structure on or defining at least a portion of a surface of the body and oriented such that the raised members are substantially aligned with a direction of localized flow on the body. An aerodynamic device for enhancing lift and reducing drag of a flying disc, wherein the plurality of raised members are situated adjacent one another to form a continuous structure and the raised members are oriented in a substantially circumferential direction on the surface of the flying disc.

A novel passive control technique for laminar flow over air transportation vehicles and space reentry vehicles flying at high supersonic and hypersonic speeds is disclosed. The control of laminar flow can be achieved by applying an array of surface roughness elements in the region before the laminar-turbulent transition. For example, an array of two-dimensional rings, stripes, or closely packed three-dimensional isolated roughness elements may be used to stabilize the instability waves and delay transition. The roughness elements may have a height between 40% and 60% of the local boundary-layer thickness. The exact location, height, and spacing of surface roughness elements may be determined by a numerical simulation strategy based on the most unstable second mode, e.g. using known e.sup.N transition prediction method, experimental measurement, or any other suitable technique.

A body adapted for relative movement with respect to a fluid, said movement creating a flow of fluid with respect to the body in a relative flow direction, said body having at least one surface with a surface profile exposed to the fluid and comprising at least one smooth step facing in relative flow direction towards the flow, said step having a height between 4% and 30% of the local boundary layer thickness (.sub.99) of the fluid contacting the body in the vicinity of the step.

Method and device for producing riblets by applying the riblets by laser interference patterning by a carbon dioxide laser.