Special Coverage

Distributed Propulsion Concepts and Superparamagnetic Energy Harvesting Hummingbird Engine
Aerofoam
Wet Active Chevron Nozzle for Controllable Jet Noise Reduction
Magnetic Relief Valve
Locking Mechanism for a Flexible Composite Hinge
Active Aircraft Pylon Noise Control System
Unmanned Aerial Systems Traffic Management
Method of Bonding Dissimilar Materials
Sonar Inspection Robot System
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Wet Active Chevron Nozzle for Controllable Jet Noise Reduction

The noise-reduction system makes use of injectors placed on the inside trailing edge of a jet engine nozzle.NASA’s Langley Research Center researchers have developed a novel noise reduction system for jet engines. Aircraft jet engine noise is a major issue for airports, the communities near airports, and, of course, for the jet engine designers. Even with the use of recent high-bypass-ratio jet engine designs, noise continues to be a major concern. The present innovation represents a significant advancement to the concept of using mechanically fixed chevrons on the trailing edge of jet engine nozzles to reduce noise. While the effect of chevrons on noise reduction is well known, commercial implementation has been limited. Unfortunately, the turbulence created with the chevrons, while useful for reducing noise upon takeoff, serves to reduce efficiency during cruising. The present innovation is a simple noise reduction system with effects similar to that of chevrons, yet it is active and controllable to maximize noise reduction while maintaining efficiency.

Posted in: Briefs, Aeronautics, Aerospace

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Improvements to the Functional Beamforming Formula

The purpose of this work is to improve the signal-to-noise ratio of acoustic measurements made in a wind tunnel with a microphone phased array. The functional beamforming method is improved to compensate for effects of acoustic propagation through turbulence, and to correct for inaccurate steering vectors. This increases the accuracy with which acoustic measurements can be made in a non-acoustic or acoustic wind tunnel.

Posted in: Briefs, Aeronautics, Aerospace

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Aerofoam

This foam composite insulation can be optimized for different material properties.Aerofoam is a unique foam composite insulation with improved thermal and acoustic insulation properties. The novelty of this invention comes from combining a polymer foam with a unique inorganic filler in a way that maximizes thermal performance while maintaining mechanical performance, chemical resistance, fire resistance, and acoustic insulation capabilities. The development of new manufacturing processes has also allowed for the development of these unique composite materials.

Posted in: Briefs, Materials

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Composite Pressure Vessel Including Crack Arresting Barrier

NASA’s Marshall Space Flight Center innovators have developed several new designs and methods of fabrication for composite and composite-overwrapped tank vessels that help significantly improve their structural integrity against impact, abrasion, harsh environments, and fire. Several embodiments of this technology portfolio also enable production of composite tanks capable of transporting liquefied natural gas or other cryogenic liquids. These innovations are applicable to important aerospace needs, including propulsion systems, as well as new and growing fields such as natural gas transportation.

Posted in: Briefs, Materials

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Process for Preparing Aerogels from Polyamides

This technology can be used in construction, garments, appliances, and camping gear.Sometimes referred to as “solid smoke,” aerogels are the world’s lightest solid materials, composed of approximately 85% air by volume. Polyamide aerogels open up a whole new world of applications due to their unique properties: translucent like silica aerogels, thermoplastic, ultra-low density, superior mechanical properties, low-temperature operating range, and highly flexible (as compared to NASA Glenn’s polyimide aerogels). Polyamide aerogels are further novel because of their tunable glass transition temperatures, meaning that crystallinity — and hence strength — can be controlled via operating temperature. Addressing the key drawbacks of aerogel technology (hydroscopicity, fragility, cost), NASA Glenn’s suite of organic aerogels is cost-competitive with both existing silica aerogels and, with scale-up, high-end foamed polymer insulation. Finally, Glenn’s materials are truly multi-functional — they can be structural members while providing superior thermal properties and extremely low dielectric (near that of air).

Posted in: Briefs, Materials

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Advanced Multilayer Environmental Barrier Coatings

Innovators at NASA’s Glenn Research Center have created exciting new developments in thermal barrier coatings, both in the chemical compositions of the coatings and in the process by which they are applied. NASA’s researchers have developed a revolutionary bond coat system that improves the performance of silicon-carbide/silicon- carbide ceramic matrix composites (SiC/SiC CMCs). This groundbreaking system enables higher-temperature operating conditions, protects against erosion and corrosion, and reduces mechanical loading. NASA’s scientists have also designed a means of creating multilayer thermal and environmental barriers with a remarkable new deposition technique to improve the coverage and quality of the coatings.

Posted in: Briefs, Coatings & Adhesives, Materials

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Magnetic Relief Valve

A side view of the relief valve sections (left), and a view inside the relief valve (right). A magnetically retained pressure-relief valve enables quick-open on/off operation when overpressure is reached.Inventors at NASA’s Kennedy Space Center have developed a magnetically retained, fast-response pressure relief valve that is designed to fully open at precise cracking pressures, and that operates in a fully open/fully closed manner. The use of a magnetically controlled relief valve, as opposed to a spring-based relief valve, enables quick-open on/off relief operation when overpressure is reached. This is due to the rapid decay of the magnetic field as the fluid medium pushes the valve poppet to an open position. Spring-based relief valves require increasing pressure and force to continually compress the spring and open the relief valve. This requirement greatly complicates the design of a system relief mechanism. A magnetic relief valve reduces these design complexities by eliminating the spring.

Posted in: Briefs, Mechanical Components, Mechanics, Fluid Handling

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