Tech Exchange

Lightning Strike Protection for Composite Aircraft

NASA’s work in advanced aeronautics includes growing interest in environmentally responsive aircraft, one component of which involves use of composites to significantly reduce weight and, hence, fuel consumption. The new Boeing 787 aircraft is one recent example, and there has been a strong move toward composites in new general aviation and business jet aircraft. One disadvantage of this new direction is that the aircraft are far more vulnerable to lightning strikes. The energy deposited in a typical lightning strike involves tens of KV and 10,000-200,000 amperes, occurring in a fraction of a second. Without some type of shielding, or conductive path, the electrically insulated carbon fiber/ epoxy composites can be damaged, particularly at the entry and exit points for the strike. The aircraft instrumentation can also be damaged in such an event and extra shielding is often necessary for composite aircraft.What are the Challenges? Improved means are needed to identify when a plane is in fact struck by lightning, and both onboard and ground-based NDE methods are needed to assess the level of damage that occurred. Perhaps more importantly, means to eliminate or mitigate damage must be engineered in a cost-effective manner, ideally as a single “outer” shield that will protect the aircraft from both structural damage as well as shield instruments without additional internal hardware requirements.What is NASA Doing? Lightning damage detection/diagnosis technologies do not exist today for our modern fleet of aircraft, so one element of NASA’s program is to explore how this can be best accomplished both during flight and after the fact. Onboard current sensors will be used to measure the intensity and location of the lightning current during a strike. Simulations of lightning-arc events in the laboratory (see photo) with various test panels will provide baseline data for model development. The voltage/current measurements from such tests will be correlated against statistical data sets to estimate the level of damage expected on the composite and eventually to evaluate the safety risks associated with continuing the flight profile after a lightning strike has occurred. Since the aircraft fuselage and wing structure can be very complex, it will be important to develop physics-based models of the lightning strike event. This code would allow designers to consider different material solutions for test and evaluation and eventually should allow good correlation between the model and observed lightning strike effects in the field.What Applications Does NASA Envision? NASA intends this information and model to be made available to composite aircraft developers as a tool in their design efforts. Similar issues are faced in the wind turbine industry where the blades can be composites. There may also be applications in the electric power industry related to arc events in very high-voltage environments. What are NASA’s Needs? NASA is interested in collaborating with industry or university groups in several areas. On-board sensors for measurement of lightning strike intensity, location, and current flow during the event.Conductive paint technology or other “coating” concepts for composites to facilitate current flow, hence mitigate or eliminate structural damage, and/or remove any need for additional internal shielding of electronics.Physics-based models of complex composite structures/actual aircraft that can be adapted to include model lightning strike events to quantify electrical, mechanical, and thermal parameters to indicate damage. More Information For more information, contact Mr. George Szatkowski at 757-864-6194 or email nasa@techbriefs.com.

Posted in: NASA Tech Needs

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Moisture Release Technologies

A company seeks technologies enabling a woven or nonwoven substrate to contain liquid/fluid that can be released by applying pressure (to yield a moist/wet substrate). They are interested in solutions that will enable water or other liquids/ fluids to be contained within a substrate and then released under moderate pressure (for example, by squeezing the substrate in your hand). The technology solution must be able to incorporate sufficient liquid content in the substrate so that when pressure is applied, approximately 75% of that substrate unit becomes moist. Respond to this TechNeed at: www.techbriefs.com/tn/200906c.htmlEmail: nasatech@yet2.com Phone: 781-972-0600

Posted in: NASA Tech Needs, Tech Needs

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Binder Solutions for the Manufacture of Molds and, Cores in Metal Castings

Binders used for molding are typically self-setting, so that after mixing two or more binder components into sand, there is a short delay before the mixture starts to set hard. Binders used for core-making are typically gas-cured. A company seeks an environmentally acceptable binder system that could be based on inorganic, “clean” organic, or hybrid derivatives, and offers an immediate advantage over current systems in terms of health, safety, and environmental issues. Respond to this TechNeed at: www.techbriefs.com/tn/200906d.htmlEmail: nasatech@yet2.com Phone: 781-972-0600

Posted in: NASA Tech Needs, Tech Needs

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Gaseous Helium (GHe) Conservation and Recovery

John C. Stennis Space Center provides rocket engine propulsion testing for the NASA space programs. Since the development of the Space Shuttle, every Space Shuttle Main Engine (SSME) has gone through acceptance testing before going to Kennedy Space Center for integration into the Space Shuttle. The SSME is a large cryogenic rocket engine that used Liquid Oxygen (LO2) and Liquid Hydrogen (LH2) as propellants. Due to the extremely cold cryogenic conditions of this environment, an inert gas, helium, is used as a purge for the engine since it can be used without freezing in the cryogenic environment. As NASA moves to the development of the new ARES launch system, the main engines as well as the upper stage engine will use cryogenic propellants, and will require gaseous helium during the development testing of each of these engines. The main engine for the ARES will be similar in size to the SSME. Technology Needs Due to the size of the SSME and the test facilities required to test the engine, extremely large quantities of helium are used during testing each year. This requirement makes Stennis one of the world’s largest users of gaseous helium, which is a non-renewable natural resource. Cost of helium is increasing as the supply diminishes. The cost and shortage of helium are beginning to impact testing of the rocket engines for the space propulsion systems. Innovative solutions are needed for efficient, cost-effective, in-situ methods to recapture helium used during the engine purging and testing processes, to re-clean the captured helium, to re-pressurize it, and then to reintroduce it for reuse. Research into technologies in these areas, demonstration of the technology capability, and conceptual design for the technology installation at Stennis are desired to assist in the helium reuse. Technology Challenges Helium used in rocket engine purge must meet very specific cleanliness standards. One of the challenges will be to develop an in-situ, on-site helium re-utilization system capable of recycling the helium to cleanliness standards requirements. The technologies developed to recapture and clean the helium must be cost-effective and able to perform the recycling process in an in-situ rocket engine test area environment. Such technologies will be required to comply with all safety and quality standards required in this environment. More Information For additional information, contact John Lansaw at Stennis Space Center, 228-688-1962, or visit nasa@techbriefs.com.

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Single-Motion Extension Mechanism for Poles

Originally developed and marketed as an extension pole for painting, light bulb changing, and similar operations, the single-motion extension principle in this technology is adaptable to any rod or pole that must be extended and retracted to a compact length. It applies to extendable antennae; tent poles; emergency equipment such as stretchers, cots, or IV poles; tools; robotic arms; or surgical instruments that must extend and retract once in the body. The internal mechanism uses a metal tape similar to that in a retractable tape measure that pushes on the extending tube. The mechanism may be hand-operated or motorized, but either way, a single motion extends the pole. The internal, contained mechanism of the extension pole provides a singlemotion extension to about three times the collapsed length of the assembly. The assembly can be fabricated in a variety of materials in a variety of tensile and compression strengths in multiple segments. The assembly can scale up to greater lengths or be miniaturized to suit the application. Get the complete report on this technology at: www.techbriefs.com/tow/200905a.html Email: nasatech@yet2.com Phone: 781-972-0600

Posted in: Techs for License

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Modular Electronic Air Sterilization Technology for Airborne Bacteria, Molds, and Viruses

This technology sterilizes air, eliminating odors, preventing infections, and extending the shelf life of food. The scalable system results in 100% removal of microorganisms with one passthrough of air. The technology has optimized UV exposure with a specialized lamp construction and array formation. The system can be modularized according to the required volume flows, and can react to changes via its proprietary microchip technology. It can be used in conjunction with HEPA filters to remove all unwanted bodies within an air stream. The underlying technology deals with the variation in atmospheric conditions. The system is made up of a series of highly developed tubular modules that include a unique internal intelligent microchip that understands changes in the humidity and temperature of the atmosphere and adapts the optimized UV exposure and flow in the unit (or series of units) to apply the minimum power required to achieve full sterilization. Get the complete report on this technology at: www.techbriefs.com/tow/200905b.html Email: nasatech@yet2.com Phone: 781-972-0600

Posted in: Techs for License

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3D and/or Flock Printing Technology

A company seeks a printing capability and/or technology that creates a physical 3D texture that is tactile and soft (but not rubbery) in nature onto a flat or curved plastic surface made of polyethylene, polypropylene, or polyester material. This 3D printing enhances the product experience for the consumer by providing a more tactile surface that can increase grip, provide a pleasant texture/feeling, and/or present a less plain/sterile surface. Materials should be FDA food-safe, as well as safe when in contact with skin. Respond to this TechNeed at: www.techbriefs.com/tn/200905c.html Email: nasatech@yet2.com Phone: 781-972-0600

Posted in: NASA Tech Needs

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