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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 883 records · Page 49
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NASA NTRS2007

A Turbine-powered UAV Controls Testbed

The latest version of the NASA Flying Controls Testbed (FLiC) integrates commercial-off-the-shelf components including airframe, autopilot, and a small turbine engine to provide a low cost experimental flight controls testbed capable of sustained speeds up to 200 mph. The series of flight tests leading up to the demonstrated performance of the vehicle in sustained, autopiloted 200 mph flight at NASA Wallops Flight Facility's UAV runway in August 2006 will be described. Earlier versions of the FLiC were based on a modified Army target drone, AN/FQM-117B, developed as part of a collaboration between the Aviation Applied Technology Directorate at Fort Eustis, Virginia and NASA Langley Research Center. The newer turbine powered platform (J-FLiC) builds on the successes using the relatively smaller, slower and less expensive unmanned aerial vehicle developed specifically to test highly experimental flight control approaches with the implementation of C-coded experimental controllers. Tracking video was taken during the test flights at Wallops and will be available for presentation at the conference. Analysis of flight data from both remotely piloted and autopiloted flights will be presented. Candidate experimental controllers for implementation will be discussed. It is anticipated that flight testing will resume in Spring 2007 and those results will be included, if possible.

Motter, Mark A.↗
NASA NTRS2007

Anthropometric Accommodation in Space Suit Design

Design requirements for next generation hardware are in process at NASA. Anthropometry requirements are given in terms of minimum and maximum sizes for critical dimensions that hardware must accommodate. These dimensions drive vehicle design and suit design, and implicitly have an effect on crew selection and participation. At this stage in the process, stakeholders such as cockpit and suit designers were asked to provide lists of dimensions that will be critical for their design. In addition, they were asked to provide technically feasible minimum and maximum ranges for these dimensions. Using an adjusted 1988 Anthropometric Survey of U.S. Army (ANSUR) database to represent a future astronaut population, the accommodation ranges provided by the suit critical dimensions were calculated. This project involved participation from the Anthropometry and Biomechanics facility (ABF) as well as suit designers, with suit designers providing expertise about feasible hardware dimensions and the ABF providing accommodation analysis. The initial analysis provided the suit design team with the accommodation levels associated with the critical dimensions provided early in the study. Additional outcomes will include a comparison of principal components analysis as an alternate method for anthropometric analysis.

Rajulu, Sudhakar↗
NASA NTRS2007

Development of a Pressure Sensitive Paint System for Measuring Global Surface Pressures on Rotorcraft Blades

This paper will describe the results from a proof of concept test to examine the feasibility of using Pressure Sensitive Paint (PSP) to measure global surface pressures on rotorcraft blades in hover. The test was performed using the U.S. Army 2-meter Rotor Test Stand (2MRTS) and 15% scale swept rotor blades. Data were collected from five blades using both the intensity- and lifetime-based approaches. This paper will also outline several modifications and improvements that are underway to develop a system capable of measuring pressure distributions on up to four blades simultaneously at hover and forward flight conditions.

Watkins, A. Neal↗
NASA NTRS2006

Surface Control of Cold Hibernated Elastic Memory Self-Deployable Structure

A new class of simple, reliable, lightweight, low packaging volume and cost, self-deployable structures has been developed for use in space and commercial applications. This technology called 'cold hibernated elastic memory' (CHEM) utilizes shape memory polymers (SMP)in open cellular (foam) structure or sandwich structures made of shape memory polymer foam cores and polymeric composite skins. Some of many potential CHEM space applications require a high precision deployment and surface accuracy during operation. However, a CHEM structure could be slightly distorted by the thermo-mechanical processing as well as by thermal space environment Therefore, the sensor system is desirable to monitor and correct the potential surface imperfection. During these studies, the surface control of CHEM smart structures was demonstrated using a Macro-Fiber Composite (MFC) actuator developed by the NASA LaRC and US Army ARL. The test results indicate that the MFC actuator performed well before and after processing cycles. It reduced some residue compressive strain that in turn corrected very small shape distortion after each processing cycle. The integrated precision strain gages were detecting only a small flat shape imperfection indicating a good recoverability of original shape of the CHEM test structure.

glass transition temperature Tg↗
NASA NTRS2007

Advances in Materials and System Technology for Portable Fuel Cells

This viewgraph presentation describes the materials and systems engineering used for portable fuel cells. The contents include: 1) Portable Power; 2) Technology Solution; 3) Portable Hydrogen Systems; 4) Direct Methanol Fuel Cell; 5) Direct Methanol Fuel Cell System Concept; 6) Overview of DMFC R&D at JPL; 7) 300-Watt Portable Fuel Cell for Army Applications; 8) DMFC units from Smart Fuel Cell Inc, Germany; 9) DMFC Status and Prospects; 10) Challenges; 11) Rapid Screening of Well-Controlled Catalyst Compositions; 12) Screening of Ni-Zr-Pt-Ru alloys; 13) Issues with New Membranes; 14) Membranes With Reduced Methanol Crossover; 15) Stacks; 16) Hybrid DMFC System; 17) Small Compact Systems; 18) Durability; and 19) Stack and System Parameters for Various Applications.

Li-ion batteries↗
NASA NTRS2006

The Road to Mach 10: A History of the X-43A Hypersonic Flight Test Program at NASA Dryden -- Origins to First Flight

The NASA Dryden Flight Research Center, in partnership with the NASA Langley Research Center and industrial contractors, conducted the first flight tests of a supersonic combustion ramjet (scramjet) in 2004. This was a revolutionary airbreathing engine able to operate at speeds above Mach 5, which carries potential for both high-speed atmospheric flight and as a space launcher. For the Dryden engineers, the X-43 program was the culmination of a nearly 60-year history of flight research, going back to the early days of supersonic flight, and to rocket planes such as the X-1, D-558-II Skyrocket, and the X-15. For the propulsion community, it marked a turning point in a quest that had taken nearly as long. The scramjet engine did not arise from the work of a single individual or from a single technological breakthrough. It evolved instead from work under way on ramjets in the early 1950s, and from research programs at the National Advisory Committee for Aeronautics (NACA) Lewis Research Center, at the U.S. Army Aberdeen Proving Ground, and by the U.S. Navy. Studies developed in the course of these disparate projects raised the possibility of supersonic combustion. Many researchers had considered the notion impractical due to the difficulty of stabilizing a flame front in a supersonic airflow. NACA researchers at Lewis attempted to test the idea's feasibility by burning aluminum borohydride in a supersonic wind tunnel. Sustained burning was believed to have been observed at Mach 1.5, Mach 2, and Mach 3 for as long as two seconds.

Peebles, Curtis↗
NASA NTRS2006

Overcoming Present-Day Powerplant Limitations Via Unconventional Engine Configurations

The Army Research Laboratory s Vehicle Technology Directorate is sponsoring the prototype development of three unconventional engine concepts - two intermittent combustion (IC) engines and one turbine engine (via SBIR (Small Business Innovative Research) contracts). The IC concepts are the Nutating Engine and the Bonner Engine, and the turbine concept is the POWER Engine. Each of the three engines offers unique and greatly improved capabilities (which cannot be achieved by present-day powerplants), while offering significant reductions in size and weight. This paper presents brief descriptions of the physical characteristics of the three engines, and discusses their performance potentials, as well as their development status.

Meitner, Peter L.↗
NASA NTRS2007

Modeling Tool Advances Rotorcraft Design

Continuum Dynamics Inc. (CDI), founded in 1979, specializes in advanced engineering services, including fluid dynamic modeling and analysis for aeronautics research. The company has completed a number of SBIR research projects with NASA, including early rotorcraft work done through Langley Research Center, but more recently, out of Ames Research Center. NASA Small Business Innovation Research (SBIR) grants on helicopter wake modeling resulted in the Comprehensive Hierarchical Aeromechanics Rotorcraft Model (CHARM), a tool for studying helicopter and tiltrotor unsteady free wake modeling, including distributed and integrated loads, and performance prediction. Application of the software code in a blade redesign program for Carson Helicopters, of Perkasie, Pennsylvania, increased the payload and cruise speeds of its S-61 helicopter. Follow-on development resulted in a $24 million revenue increase for Sikorsky Aircraft Corporation, of Stratford, Connecticut, as part of the company's rotor design efforts. Now under continuous development for more than 25 years, CHARM models the complete aerodynamics and dynamics of rotorcraft in general flight conditions. CHARM has been used to model a broad spectrum of rotorcraft attributes, including performance, blade loading, blade-vortex interaction noise, air flow fields, and hub loads. The highly accurate software is currently in use by all major rotorcraft manufacturers, NASA, the U.S. Army, and the U.S. Navy.

Source record↗
NASA NTRS2007

Treatment Prevents Corrosion in Steel and Concrete Structures

In the mid-1990s, to protect rebar from corrosion, NASA developed an electromigration technique that sends corrosion-inhibiting ions into rebar to prevent rust, corrosion, and separation from the surrounding concrete. Kennedy Space Center worked with Surtreat Holding LLC, of Pittsburgh, Pennsylvania, a company that had developed a chemical option to fight structural corrosion, combining Surtreat's TPS-II anti-corrosive solution and electromigration. Kennedy's materials scientists reviewed the applicability of the chemical treatment to the electromigration process and determined that it was an effective and environmentally friendly match. Ten years later, NASA is still using this approach to fight concrete corrosion, and it has also developed a new technology that will further advance these efforts-a liquid galvanic coating applied to the outer surface of reinforced concrete to protect the embedded rebar from corrosion. Surtreat licensed this new coating technology and put it to use at the U.S. Army Naha Port, in Okinawa, Japan. The new coating prevents corrosion of steel in concrete in several applications, including highway and bridge infrastructures, piers and docks, concrete balconies and ceilings, parking garages, cooling towers, and pipelines. A natural compliment to the new coating, Surtreat's Total Performance System provides diagnostic testing and site analysis to identify the scope of problems for each project, manufactures and prescribes site-specific solutions, controls material application, and verifies performance through follow-up testing and analysis.

Source record↗
NASA NTRS1991

Optical correlator method and apparatus for particle image velocimetry processing

Young's fringes are produced from a double exposure image of particles in a flowing fluid by passing laser light through the film and projecting the light onto a screen. A video camera receives the image from the screen and controls a spatial light modulator. The spatial modulator has a two dimensional array of cells the transmissiveness of which are controlled in relation to the brightness of the corresponding pixel of the video camera image of the screen. A collimated beam of laser light is passed through the spatial light modulator to produce a diffraction pattern which is focused onto another video camera, with the output of the camera being digitized and provided to a microcomputer. The diffraction pattern formed when the laser light is passed through the spatial light modulator and is focused to a point corresponds to the two dimensional Fourier transform of the Young's fringe pattern projected onto the screen. The data obtained fro This invention was made with U.S. Government support awarded by the Department of the Army (DOD) and NASA grand number(s): DOD #DAAL03-86-K0174 and NASA #NAG3-718. The U.S. Government has certain rights in this invention.

Farrell, Patrick V.↗
NASA NTRS2003

An Overview of Autogyros and The McDonnell XV-1 Convertiplane

This report and its lengthy appendix first reviews early autogyro history. The period from Juan de la Cierva's invention in the early1920s through to the U. S. Army Air Corps' choice, in 1943, of the helicopter instead of the more fully developed autogyro, is examined from a technical point of view. With this historical background in hand, simple aerodynamic technology for rotors, wings, propeller, and fuselages is provided for reference. The McDonnell XV-1 convertiplane development and its program are discussed in detail, with particular emphasis on the wind tunnel and flight testing that was accomplished with two prototype aircraft in the early 1950s. The tip drive rotor system with its ingeniously designed hub was well suited to high speed rotorcraft. The configuration was conceived by Kurt Hohenemser and Fred Dubloff. Many photographs taken of the XV-1 stored at Fort Rucker are included in this report's appendix.

Harris, Franklin D.↗
NASA NTRS2008

Automated Power Assessment for Helicopter Turboshaft Engines

An accurate indication of available power is required for helicopter mission planning purposes. Available power is currently estimated on U.S. Army Blackhawk helicopters by performing a Maximum Power Check (MPC), a manual procedure performed by maintenance pilots on a periodic basis. The MPC establishes Engine Torque Factor (ETF), an indication of available power. It is desirable to replace the current manual MPC procedure with an automated approach that will enable continuous real-time assessment of available power utilizing normal mission data. This report presents an automated power assessment approach which processes data currently collected within helicopter Health and Usage Monitoring System (HUMS) units. The overall approach consists of: 1) a steady-state data filter which identifies and extracts steady-state operating points within HUMS data sets; 2) engine performance curve trend monitoring and updating; and 3) automated ETF calculation. The algorithm is coded in MATLAB (The MathWorks, Inc.) and currently runs on a PC. Results from the application of this technique to HUMS mission data collected from UH-60L aircraft equipped with T700-GE-701C engines are presented and compared to manually calculated ETF values. Potential future enhancements are discussed.

Simon, Donald L.↗
NASA NTRS2008

Study of the Correlation between the Performances of Lunar Vehicle Wheels Predicted by the Nepean Wheeled Vehicle Performance Model and Test Data

This paper describes the results of a study of the correlation between the performances of wheels for lunar vehicles predicted using the Nepean wheeled vehicle performance model (NWVPM), developed under the auspices of Vehicle Systems Development Corporation, Ottawa, Canada, and the corresponding test data presented in Performance evaluation of wheels for lunar vehicles , Technical Report M-70-2, prepared for George C. Marshall Space Flight Center, National Aeronautics and Space Administration (NASA), USA, by the US Army Engineer Waterways Experiment Station (WES). The NWVPM was originally developed for design and performance evaluation of terrestrial off-road wheeled vehicles. The purpose of this study is to assess the potential of the NWVPM for evaluating wheel candidates for the new generation of extra-terrestrial vehicles. Two versions of a wire-mesh wheel and a hoop-spring wheel, which were considered as candidates for lunar roving vehicles for the NASA Apollo program in the late 1960s, together with a pneumatic wheel were examined in this study. The tractive performances of these wheels and of a 464 test vehicle with the pneumatic wheels on air-dry sand were predicted using the NWVPM and compared with the corresponding test data obtained under Earth s gravity and previously documented in the above-named report. While test data on wheel or vehicle performances obtained under Earth s gravity may not necessarily be representative of those on extra-terrestrial bodies, because of the differences in gravity and in environmental conditions, such as atmospheric pressure, it is still a valid approach to use test data obtained under Earth s gravity to evaluate the predictive capability of the NWVPM and its potential applications to predicting wheel or wheeled rover performances on extra-terrestrial bodies. Results of this study show that, using the ratio (P20/W) of the drawbar pull to normal load at 20 per cent slip as a performance indicator, there is a reasonable correlation between the predictions and experimental data. This indicates that the NWVPM has the potential as an engineering tool for evaluating wheel candidates for a future generation of extra-terrestrial vehicles, provided that appropriate input data are available.

Wong, J. Y.↗
NASA NTRS2009

JSC Case Study: Fleet Experience with E-85 Fuel

JSC has used E-85 as part of an overall strategy to comply with Presidential Executive Order 13423 and the Energy Policy Act. As a Federal fleet, we are required to reduce our petroleum consumption by 2 percent per year, and increase the use of alternative fuels in our vehicles. With the opening of our onsite dispenser in October 2004, JSC became the second federal fleet in Texas and the fifth NASA center to add E-85 fueling capability. JSC has a relatively small number of GSA Flex Fuel fleet vehicles at the present time (we don't include personal vehicles, or other contractor's non-GSA fleet), and there were no reasonably available retail E-85 fuel stations within a 15-minute drive or within five miles (one way). So we decided to install a small 1000 gallon onsite tank and dispenser. It was difficult to obtain a supplier due to our low monthly fuel consumption, and our fuel supplier contract has changed three times in less than five years. We experiences a couple of fuel contamination and quality control issues. JSC obtained good information on E-85 from the National Ethanol Vehicle Coalition (NEVC). We also spoke with Defense Energy Support Center, (DESC), Lawrence Berkeley Laboratory, and US Army Fort Leonard Wood. E-85 is a liquid fuel that is dispensed into our Flexible Fuel Vehicles identically to regular gasoline, so it was easy for our vehicle drivers to make the transition.

Hummel, Kirck↗
NASA NTRS1948

Performance of Compressor of XJ-41-V Turbojet Engine II - Static-Pressure Ratios and Limitation of Maximum Flow at Equivalent Compressor Speed of 8000 rpm

At the request of the Air Material Command, Army Air Forces, an investigation was conducted by the NACA Cleveland laboratory to determine the performance characteristics of the compressor of the XJ-41-V turbojet engine. This report is the second in a series presenting the compressor performance and analysis of flow conditions in the compressor. The static-pressure variation in the direction of flow through the compressor and the location and the cause of the maximum flow restriction at an equivalent speed of 8000 rpm are presented. After the initial runs were reported, the leading edges of the impeller blades and the diffuser surfaces were found to have been roughened by steel particles from a minor failure of auxiliary equipment. The leading edges of the impeller blades were refinished and all high spots resulting from scratches in the diffuser and the accessible parts of the vaned collector passages were removed. The initial overall performance and that obtained with the refinished blades are presented.

Dildine, Dean M.↗
NASA NTRS1947

Performance of Compressor of XJ-41-V Turbojet Engine: Compressor Static-Pressure Rise at Equivalent Compressor Speeds of 5000, 7000, 8000, and 9000 rpm - 3

At the request of the Air Materiel Command, Army Air Forces, an investigation is being conducted at the NACA Cleveland laboratory to determine the performance characteristics of the XJ-41-V turbojet-engine compressor. The static-pressure variation in the direction of flow through the compressor was presented in reference 1 for an equivalent speed of 8000 rpm. An analysis of these pressure indicated that the maximum-flow limitation of the compressor was caused by separation, which reduced the effective flow area at the vaned-collector entrance. As a result of this analysis, the flow area at the vaned-collector entrance was increased to obtain larger mass flows. The area increase was obtained by cutting back the entrance edges of the collector vanes, which resulted in an increased vaneless-diffuser radius. Comparative performance of the original and revised compressors at an equivalent speed of 8000 rpm is presented. The static-pressure rise through the compressor, determined from static pressures at the impeller entrance and the vaned-collector exit, is also presented together with the compressor adiabatic efficiency and the mass flow over an equivalent speed range from 5000 to 9000 rpm. These static-pressure data are presented for the purpose of correlating the compressor performance with the turbojet-engine performance.

Creagh, John W. R.↗
NASA NTRS2009

Concept, Simulation, and Instrumentation for Radiometric Inflight Icing Detection

The multi-agency Flight in Icing Remote Sensing Team (FIRST), a consortium of the National Aeronautics and Space Administration (NASA), the Federal Aviation Administration (FAA), the National Center for Atmospheric Research (NCAR), the National Oceanographic and Atmospheric Administration (NOAA), and the Army Corps of Engineers (USACE), has developed technologies for remotely detecting hazardous inflight icing conditions. The USACE Cold Regions Research and Engineering Laboratory (CRREL) assessed the potential of onboard passive microwave radiometers for remotely detecting icing conditions ahead of aircraft. The dual wavelength system differences the brightness temperature of Space and clouds, with greater differences potentially indicating closer and higher magnitude cloud liquid water content (LWC). The Air Force RADiative TRANsfer model (RADTRAN) was enhanced to assess the flight track sensing concept, and a 'flying' RADTRAN was developed to simulate a radiometer system flying through simulated clouds. Neural network techniques were developed to invert brightness temperatures and obtain integrated cloud liquid water. In addition, a dual wavelength Direct-Detection Polarimeter Radiometer (DDPR) system was built for detecting hazardous drizzle drops. This paper reviews technology development to date and addresses initial polarimeter performance.

Ryerson, Charles↗
NASA NTRS1934

Resume of Present Data on Load Distribution on Slots and Flaps, Special Report

This report covers a study of the generally available data on load distribution on slots and flaps. The study was made by the National Advisory Committee for Aeronautics at the request of the Material Division, Army Air Corps to furnish information applicable to design criteria for slots and flaps of various types. The data are presented in three main sections: slots (Handley page type), auxiliary airfoils (fixed), and flaps.

Wenzinger, Carl J.↗