Manufacturing & Prototyping

Triaxial Swirl Injector Element for Liquid-Fueled Engines

The design is amenable to low-cost production.

A triaxial injector is a single bi-propellant injection element located at the center of the injector body. The injector element consists of three nested, hydraulic swirl injectors. A small portion of the total fuel is injected through the central hydraulic injector, all of the oxidizer is injected through the middle concentric hydraulic swirl injector, and the balance of the fuel is injected through an outer concentric injection system. The configuration has been shown to provide good flame stabilization and the desired fuel-rich wall boundary condition.

Posted in: Briefs, Manufacturing & Prototyping, Liquid propellants, Nozzles, Fuel injection, Hydraulic equipment

Coaxial Propellant Injectors With Faceplate Annulus Control

These injectors are simpler and less expensive, relative to prior coaxial injectors.

An improved design concept for coaxial propellant injectors for a rocket engine (or perhaps for a non-rocket combustion chamber) offers advantages of greater robustness, less complexity, fewer parts, lower cost, and less bulk, relative to prior injectors of equivalent functionality. This design concept is particularly well suited to small, tight-tolerance injectors, for which prior designs are not suitable because the practical implementation of those designs entails very high costs and difficulty in adhering to the tolerances.

Posted in: Briefs, Manufacturing & Prototyping, Propellants, Fuel injection, Rocket engines

Adaptable Diffraction Gratings With Wavefront Transformation

Better resolution and aberration control are possible with a dynamic refractive grating.

Diffraction gratings are optical components with regular patterns of grooves, which angularly disperse incoming light by wavelength. Traditional diffraction gratings have static planar, concave, or convex surfaces. However, if they could be made so that they can change the surface curvature at will, then they would be able to focus on particular segments, self-calibrate, or perform fine adjustments.

Posted in: Briefs, TSP, Manufacturing & Prototyping, Calibration, Optics, Smart materials

Particle Distribution on Webs or Cloths

This technology provides the ability to uniformly distribute and attach particulate matter onto fibrous composite sheet or web materials.

This technology provides a methodology and products that are formed from fibrous substrates or film-like surfaces by uniform impregnation with a particulate that is subsequently firmly attached. The extremely uniform distribution of the particulate is accomplished by 1) electrically charging a fibrous matrix with individual exposed surfaces to create a uniform distribution of charged sites; 2) applying particulates to this matrix so that particulates adhere at the charged sites; and 3) the particulates are attached to the individual fibers within the substrate by firm non-transient bonding.

Posted in: Briefs, MDB, Briefs, Manufacturing & Prototyping, Coatings & Adhesives, Materials, Bio-Medical, Medical, Medical equipment and supplies, Fabrics, Fibers, Materials properties

Photochemical Tissue Bonding for Military Medical Applications

A two-wavelength laser and albumen stent easily repair separated vessels.

Joining severed vessels is a recurring problem in trauma and surgery. The basic technology of joining vessels using sutures has been available for centuries, but remains a slow and tedious process. A complete system for micro-anastomosis of vessels was developed that involves a laser in a clinically useful form factor, and a novel albumen stent to support the vessel during the surgery.

Posted in: Briefs, MDB, TSP, Briefs, TSP, Manufacturing & Prototyping, Bio-Medical, Medical, Photonics, Lasers, Cardiovascular system, Medical equipment and supplies, Surgical procedures

Inflatable Tubular Structures Rigidized With Foams

Lightweight booms could be deployed from compact stowage and rigidized in place.

Inflatable tubular structures that have annular cross sections rigidized with foams, and the means of erecting such structures in the field, are undergoing development. Although the development effort has focused on lightweight structural booms to be transported in compact form and deployed in outer space, the principles of design and fabrication are also potentially applicable to terrestrial structures, including components of ultralightweight aircraft, lightweight storage buildings and shelters, lightweight insulation, and sales displays.

Posted in: Briefs, Manufacturing & Prototyping, Product development, Packaging, Foams, Lightweight materials, Parts

Constant-Differential-Pressure Two-Fluid Accumulator

An improved design does not rely on the spring rate of the accumulator tank.

A two-fluid accumulator has been designed, built, and demonstrated to provide an acceptably close approximation to constant differential static pressure between two fluids over the full ranges of (1) accumulator stroke, (2) rates of flow of the fluids, and (3) common static pressure applied to the fluids. Prior differential-pressure two-fluid accumulators are generally not capable of maintaining acceptably close approximations to constant differential pressures.

Posted in: Briefs, Manufacturing & Prototyping, Springs, Containers, Pumps

Venting Closed-Cell Foam Panels

Stresses caused by differential gas pressures are reduced.

A technique for reducing in-flight loss of closed-cell foam insulation has been devised. In the original application, foam is used for thermal insulation on the external tank of the space shuttle. As the space shuttle ascends, aerodynamic effects cause an increase in surface temperature of the foam. This heating increases the internal cell gas pressure and reduces cell wall strength. The difference between the increasing pressure of the gases trapped in the foam cells and the decreasing pressure of the ambient air contribute to stresses that can break off pieces of foam during flight. Perforating the foam with small holes makes it possible for some trapped gases to escape, reducing the stresses sufficiently to keep the foam intact during ascent. This technique reduced in-flight foam loss by more than 95 percent. The vent holes could offer similar benefits in other applications where materials are subjected to thermal and pressure gradients.

Posted in: Briefs, TSP, Manufacturing & Prototyping, Thermodynamics, Foams, Insulation, Spacecraft

Chemical Machining of Microscopic Holes and Grooves in Glass

This technique overcomes disadvantages of conventional macro- and micromachining.

A technique for making precise, microscopic holes and grooves in glass workpieces has been invented. The technique differs from both (1) traditional macroscopic mechanical drilling and milling and (2) conventional micromachining that involves etching through photolithographically patterned masks. The technique can be used, for example, to make holes between 20 µm and 1 mm in diameter.

Posted in: Briefs, Manufacturing & Prototyping, Machining processes, Manufacturing equipment and machinery, Chemicals, Glass, Nozzles

Two Concepts for Deployable Trusses

Thermal-actuation and misalignment-tolerant double-pivot designs are proposed.

Two concepts that could be applied separately or together have been suggested to enhance the utility of deployable truss structures. The concepts were intended originally for application to a truss structure to be folded for compact stowage during transport and subsequently deployed in outer space. The concepts may also be applicable, with some limitations, to deployable truss structures designed to be used on Earth.

Posted in: Briefs, Manufacturing & Prototyping, Aircraft structures, Design processes, Spacecraft

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