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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 325 records · Page 18
All sourcesNASA NTRSDOE OSTI
NASA NTRS1980

Methodology for urban rail and construction technology research and development planning

A series of transit system visits, organized by the American Public Transit Association (APTA), was conducted in which the system operators identified the most pressing development needs. These varied by property and were reformulated into a series of potential projects. To assist in the evaluation, a data base useful for estimating the present capital and operating costs of various transit system elements was generated from published data. An evaluation model was developed which considered the rate of deployment of the research and development project, potential benefits, development time and cost. An outline of an evaluation methodology that considered benefits other than capital and operating cost savings was also presented. During the course of the study, five candidate projects were selected for detailed investigation; (1) air comfort systems; (2) solid state auxiliary power conditioners; (3) door systems; (4) escalators; and (5) fare collection systems. Application of the evaluation model to these five examples showed the usefulness of modeling deployment rates and indicated a need to increase the scope of the model to quantitatively consider reliability impacts.

Rubenstein, L. D.↗
NASA NTRS1981

STS-2 second space shuttle mission: Shuttle to carry scientific payload on second flight

The STS-2 flight seeks to (1) fly the vehicle with a heavier payload than the first flight; (2) test Columbia's ability to hold steady attitude for Earth-viewing payloads; (3) measure the range of payload environment during launch and entry; (4) further test the payload bay doors and space radiators; and (5) operate the Canadian-built remote manipulator arm. The seven experiments which comprise the OSTA-1 payload are described as well as experiments designed to assess shuttle orbiter performance during launch, boost, orbit, atmospheric entry and landing. The menu for the seven-day flight and crew biographies, are included with mission profiles and overviews of ground support operations.

Source record↗
NASA NTRS1980

Optimum subsonic, high-angle-of-attack nacelles

Many proposed advanced aircraft - but especially tilt-nacelle, subsonic-cruise, V/STOL aircraft - require nacelles that operate over a wide range of aerodynamic conditions. The optimum design of such nacelles and their inlets is described, including how the inlet low-speed design conditions are selected, the conditions for which the various regions of the inlet are designed, and appropriate criteria of merit. For low-speed operation the optimum internal surface velocity distributions and skin friction distributions are described for three categories of inlets: those without boundary-layer control (BLC), those with BLC, and those with blow-in door slots and retractable slats. Experimental results are presented that show the performance of the various types of inlets. At cruise speed the effect of factors that reduce the nacelle external surface area and the local skin friction is illustrated. These factors are cruise Mach number, inlet throat size, fan-face Mach number, and nacelle contour. The interrelation of these cruise-speed factors with the design requirements for good low-speed performance is discussed. Finally an inlet design without BLC and an optimized inlet design with slots and slats are compared to illustrate the possible reductions in nacelle size.

Luidens, R. W.↗
NASA NTRS1980

Goddard's new 39,000 cubic foot low frequency acoustic test facility

The Goddard Space Flight Center's 39,000 cu ft acoustic chamber for testing both shuttle-launched payloads and payloads launched by expendable vehicles is described. Chamber requirements and design problems are reviewed, and safety systems are discussed. It is shown that: (1) the maximum overall sound-pressure level obtained with two 10-kW transducers is 150 dB; (2) at least seven modes between 25 and 40 Hz have been identified in the preliminary evaluation of the chamber; (3) two discernible dips, localized to individual doors, occur in the LF spectrum, at 30-33 and 42-44 Hz; and (4) the reverberation times measured for 60-dB decay range from 7 sec at 40 Hz to a maximum of 19 sec at 125 Hz, with an average of 13.4 sec at 1000 Hz.

Kirchman, E.↗
NASA NTRS1981

Space Shuttle utilization characteristics with special emphasis on payload design, economy of operation and effective space exploitation

The reusable manned Space Shuttle has made new and innovative payload planning a reality and opened the door to a variety of payload concepts formerly unavailable in routine space operations. In order to define the payload characteristics and program strategies, current Shuttle-oriented programs are presented: NASA's Space Telescope, the Long Duration Exposure Facility, the West German Shuttle Pallet Satellite, and the Goddard Space Flight Center's Multimission Modular Spacecraft. Commonality of spacecraft design and adaptation for specific mission roles minimizes payload program development and STS integration costs. Commonality of airborne support equipment assures the possibility of multiple program space operations with the Shuttle. On-orbit maintenance and repair was suggested for the module and system levels. Program savings from 13 to over 50% were found obtainable by the Shuttle over expendable launch systems, and savings from 17 to 45% were achievable by introducing reuse into the Shuttle-oriented programs.

Turner, D. N.↗
NASA NTRS1953

Investigation of Aerodynamic and Icing Characteristics of a Flush Alternate Inlet Induction System Air Scoop

An investigation has been made in the NACA Lewis icing research tunnel to determine the aerodynamic and icing characteristics of a full-scale induction-system air-scoop assembly incorporating a flush alternate inlet. The flush inlet was located immediately downstream of the offset ram inlet and included a 180 deg reversal and a 90 deg elbow in the ducting between inlet and carburetor top deck. The model also had a preheat-air inlet. The investigation was made over a range of mass-air- flow ratios of 0 to 0.8, angles of attack of 0 and 4 deg airspeeds of 150 to 270 miles per hour, air temperatures of 0 and 25 F various liquid-water contents, and droplet sizes. The ram inlet gave good pressure recovery in both clear air and icing but rapid blockage of the top-deck screen occurred during icing. The flush alternate inlet had poor pressure recovery in both clear air and icing. The greatest decreases in the alternate-inlet pressure recovery were obtained at icing conditions of low air temperature and high liquid-water content. No serious screen icing was observed with the alternate inlet. Pressure and temperature distributions on the carburetor top deck were determined using the preheat-air supply with the preheat- and alternate-inlet doors in various positions. No screen icing occurred when the preheat-air system was operated in combination with alternate-inlet air flow.

Lewis, James P.↗
NASA NTRS1981

Development and fabrication of a solar cell junction processing system

Modifications to the ground plane, to insure a good electrical return path during the pulse discharge, were made using a ring of beryllium copper finger stock attached to the underside of the aluminum ground plate. Experiments on annealing of wafers with ion implantation damage continued. The entire surface of 100 mm diameter wafers were annealed by one pulse for the standard implant (10 keV, phosphorus, 2x10 to the 15th power ions/sq cm). While samples are being fabricated into solar cells for electrical characterization, work is continuing on improvement of the electron beam uniformity and the optimization of the diode parameters. The engineering design was completed and the manufacturing detail drawings were released for fabrication. Assembly of the subcomponents for the exit and entrance locks is almost complete. These components include the cassettes, the indexing mechanisms, main doors, and wafer carrier transfer modules. The 'Y' track and three phase transition track sections are under final assembly and test.

Giesling, R.↗
NASA NTRS1981

The spectroscopy of comets: Introductory remarks

Emphasis in cometary spectroscopy is on production rates, becuase they open the door to more fundamental clues about the origin and the history of the solar system, through the understanding of comet chemistry. In order to establish production rates quantitatively, suggestion are provided, in particular: to study the lifetimes of all hypothetical parents, against all processes of decay, namely photodissociations, photoionizations and ion-molecule reactions; and to study the velocity of all molecular fragments resulting from all the decay processes, through the balance sheet of the energy distribution before and after each decay process.

Delsemme, A. H.↗
NASA NTRS1982

Baggie: A unique solution to an orbiter icing problem

The orbiter icing problem, located in two lower surface mold line cavities, was solved. These two cavities are open during Shuttle ground operations and ascent, and are then closed after orbit insertion. If not protected, these cavities may be coated with ice, which may be detrimental to the adjacent thermal protection system (TPS) tiles if the ice breaks up during ascent, and may hinder the closing of the cavity doors if the ice does not break up. The problem of ice in these cavities was solved by the use of a passive mechanism called baggie, which is purge curtain used to enclose the cavity and is used in conjunction with gaseous nitrogen as the local purge gas. The baggie, the final solution, is unique in its simplicity, but its design and development were not. The final baggie design and its development testing are discussed. Also discussed are the baggie concepts and other solutions not used.

Walkover, L. J.↗
NASA NTRS1982

QCSEE Over-the-Wing Engine Acoustic Data

The over the wing (OTW) Quiet, Clean, Short Haul Experimental Engine (QCSEE) was tested at the NASA Lewis Engine Noise Test Facility. A boilerplate (nonflight weight), high throat Mach number, acoustically treated inlet and a D shaped OTW exhaust nozzle with variable position side doors were used in the tests along with wing and flap segments to simulate an installation on a short haul transport aircraft. All of the acoustic test data from 10 configurations are documented in tabular form. Some selected narrowband and 1/3 octave band plots of sound pressure level are presented.

Bloomer, H. E.↗
NASA NTRS1980

Space Shuttle/Orbiter EVA and EVA provisions

EVA objectives, procedures, and equipment for the Shuttle are reviewed. The EVA will occur as a planned excursion, to complete a mission objective, or on a contingency basis as support for the mission or to effect repairs to the Orbiter or its payload. Configurations for the placement of the airlock for EVA with and without Spacelab payloads are discussed, along with the various EVA tasks which could be expected as necessary for mission completion. Handholds have been placed in strategic positions on the RMS and along the payload doors, and a safety tether has been incorporated with line extension out to 25 ft. Off-the-shelf tools such as needlenose pliers, forceps, diagonal cutters, etc. are carried as standard equipment for the repair of malfunctioning equipment and doorlatches. Finally, attention is given to EVA lighting, communication, life-support, and work station restraint systems.

Goodman, J. R.↗
NASA NTRS1980

Space Telescope - Design for orbital maintenance

Maintenance and repair of the Shuttle launched Space Telescope (ST) are examined, noting that except for the basic structure, mirrors, cables, and several noncritical items, the entire ST is replaceable or reparable on-orbit. EVA tasks have been designed to avoid contamination, and to provide a reduction in Orbital Replacement Units, a minimal number of doors and openings, and minimized structural weight associated with free-volume. All removable components have been provided with tool-compatible fittings and releases, and standardization of parts has been compromised with considerations of interface with crew handling. Replacement and repair equipment will be carried as an added parcel on Shuttle flights and are not part of the standard Shuttle components. The necessity of designing for crew-aid at ST workstations is suggested to provide sound data for the design of other space-based equipment.

Fisher, H. T.↗
NASA NTRS1982

Small payloads for the Shuttle

The Goddard Space Flight Center, Special Payloads Division (sounding rockets) experience in applying rocket mechanical experience and technology to the Shuttle is presented. While the mechanical design loads are similar, new considerations for thermal extremes, material control and attachment structures must be included. These additional requirements have been successfully introduced in the free flyer class of payloads, Shuttle Pointed Automonous Research Tool for Astronomy (SPARTAN), and a motorized door for the Get Away Special (GAS) payloads.

Nygaard, M. A.↗
NASA NTRS1983

Pull Test Verifies Gap Loading

Thin plastic strip pulled away from gap by force gage to measure pressure applied on gap filler. Force necessary to initiate movement of thin plastic strip is measure of gap tightness. Procedure determines interface pressures or loads where conventional load-measuring equipment cannot be used. Used to check refrigerator-door seals.

Hagen, G. R.↗
NASA NTRS1984

Membrane Switches Check Seal Pressure

Array of flexible membrane switches used to indicate closure of seal. Switch membrane responds to pressure exerted by rigid surface on compliant sealing medium and provides switch contacts monitored electronically. Membrane switches connected in series and placed under seal. When all switches are closed lamp or LED lights up, indicating requisite seal pressure has been realized at all switch positions. Principle used to ensure integrity of seals on refrigerator and oven doors, weatherstripping, hatches, spacecraft, airplanes, and submarines.

Hodgetts, P. J.↗
NASA NTRS1984

Airflow Assists Solar Receiver

Heat loss by convection reduced. Simplified solar receiver concept involves inwardly directed flow of cooling air and "air door" to reduce loss by convection. Receiver is constructed from inexpensive materials.

Revere, W. R.↗
NASA NTRS1982

Durability of commercial aircraft and helicopter composite structures

The development of advanced composite technology during the past decade is discussed. Both secondary and primary components fabricated with boron, graphite, and Kevlar composites are evaluated. Included are spoilers, rudders, and fairings on commercial transports, boron/epoxy reinforced wing structure on C-130 military transports, and doors, fairings, tail rotors, vertical fins, and horizontal stabilizers on commercial helicopters. The development of composite structures resulted in advances in design and manufacturing technology for secondary and primary composite structures for commercial transports. Design concepts and inspection and maintenance results for the components in service are reported. The flight, outdoor ground, and controlled laboratory environmental effects on composites were also determined. Effects of moisture absorption, ultraviolet radiation, aircraft fuels and fluids, and sustained tensile stress are included. Critical parameters affecting the long term durability of composite materials are identified.

Dexter, H. B.↗
NASA NTRS1982

Durability of aircraft composite materials

Confidence in the long term durability of advanced composites is developed through a series of flight service programs. Service experience is obtained by installing secondary and primary composite components on commercial and military transport aircraft and helicopters. Included are spoilers, rudders, elevators, ailerons, fairings and wing boxes on transport aircraft and doors, fairings, tail rotors, vertical fins, and horizontal stabilizers on helicopters. Materials included in the evaluation are boron/epoxy, Kevlar/epoxy, graphite/epoxy and boron/aluminum. Inspection, maintenance, and repair results for the components in service are reported. The effects of long term exposure to laboratory, flight, and outdoor environmental conditions are reported for various composite materials. Included are effects of moisture absorption, ultraviolet radiation, and aircraft fuels and fluids.

H. Benson Dextern↗