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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 415 records · Page 23
All sourcesNASA NTRSDOE OSTI
NASA NTRS1976

Visual space perception on a computer graphics night visual attachment

A series of experiments was conducted to compare five psychophysical methods of measuring how people perceive visual space in simulators. Psychologists have used such methods traditionally to measure visual space perception in the real world. Of the five tasks - objective-size judgments, angular-size judgments, shape judgments, slant judgments, and distance judgments - only the angular-size judgment task proved to be of potential use as a measure of simulator realism. In this experiment pilots estimated the relative angular size of triangles placed at various distances along a simulated runway. Estimates made when the display was collimated were closer to real-world performance than estimates made with an uncollimated display.

Palmer, E.↗
NASA NTRS1977

Longitudinal and lateral-directional static aerodynamic characteristics of an unpowered escape system extraction rocket model with attached launch tubes

An escape system extraction rocket proposed for use on the Rotor Systems Research Aircraft was tested at Mach numbers of 0.1 and 0.3 through an angle of attack range from -2 deg to 102 deg and an angle of sideslip range from 0 deg to 15 deg in the Langley 7- by 10-foot high speed tunnel. The data are presented without analysis.

Huffman, J. K.↗
NASA NTRS1979

Quick-connect threaded attachment joint

Joint is self-aligning and tightens with only sixty-five degrees of rotation for quick connects and disconnects. Made of injection-molded plastics or cast or machined aluminum, joint can carry wires, tubes, liquids, or gases. When two parts of joint are brought together, their shapes align them. Small projections on male section and slots on female section further aid alignment; slight rotation of male form engages projections in slots. At this point, threads engage and male section is rotated until joint is fully engaged.

Lucy, M. H.↗
NASA NTRS1970

Helmet latching and attaching ring

A neck ring releasably secured to a pressurized garment carries an open-ended ring normally in the engagement position fitted into an annular groove and adapted to fit into a complementary annular groove formed in a helmet. Camming means formed on the inner surface at the end of the helmet engages the open-ended ring to retract the same and allow for one motion donning even when the garment is pressurized. A projection on the end of the split ring is engageable to physically retract the split ring.

Chase, E. W.↗
NASA NTRS1979

Attaching strain transducers to fragile materials

A-shaped clamp prevents damage to thin, brittle specimens and supports displacement transducer away from heated zone. Also it defines reference points for strain measurement on specimen surface thus preventing specimen cracking due to unequal thermal expansion between clamp and holder.

Duggan, M. F.↗
NASA NTRS1979

Design fabrication and test of graphite/polyimide composite joints and attachments for advanced aerospace vehicles

Graphite/polyimide (Gr/PI) bolted and bonded joints were investigated. Possible failure modes and the design loads for the four generic joint types are discussed. Preliminary sizing of a type 1 joint, bonded and bolted configuration is described, including assumptions regarding material properties and sizing methodology. A general purpose finite element computer code is described that was formulated to analyze single and double lap joints, with and without tapered adherends, and with user-controlled variable element size arrangements. An initial order of Celion 6000/PMR-15 prepreg was received and characterized.

Source record↗
NASA NTRS1979

High resolution threshold photoelectron spectroscopy by electron attachment

A system is provided for determining the stable energy levels of a species ion, of an atomic, molecular, or radical type, by application of ionizing energy of a predetermined level, such as through photoionization. The system adds a trapping gas to the gaseous species to provide a technique for detection of the energy levels. The electrons emitted from ionized species are captured by the trapping gas, only if the electrons have substantially zero kinetic energy. If the electrons have nearly zero energy, they are absorbed by the trapping gas to produce negative ions of the trapping gas that can be detected by a mass spectrometer. The applied energies (i.e. light frequencies) at which large quantities of trapping gas ions are detected, are the stable energy levels of the positive ion of the species. SF6 and CFCl3 have the narrowest acceptance bands, so that when they are used as the trapping gas, they bind electrons only when the electrons have very close to zero kinetic energy.

Chutjian, A.↗
NASA NTRS1980

Investigations regarding the drag characteristics of flow-disturbing bodies which are arranged in line and attached to the wall

The flow characteristics of rectangular bodies mounted on the base area of a rectangular closed wind tunnel are investigated. As many as four bodies are mounted in line with equal distances between successive bodies. The Mach number of the flowing air is in the range from 0.1 to 0.5. Total and individual drag values could be charged within a wide range by a suitable selection of the distance between successive bodies.

Balkowski, M.↗
NASA NTRS1980

Instruments and attachments for electronystagmography

A portable set of instruments and devices was developed which makes it possible to record spontaneous nystagmus with open and closed eyes. Rotational, caloric, position, and pressure nystagmus under any conditions may also be recorded.

Mironenko, Y. T.↗
NASA NTRS1980

Structural attachments for large space structures

The feasibility of fabricating beams in space and using them as components of a large, crew assembled structure, was investigated. Two projects were undertaken: (1) design and development of a ground version of an automated beam builder capable of producing triangular cross section aluminum beams; and (2) design and fabrication of lap joints to connect the beams orthogonally and centroidal end caps to connect beams end to end at any desired angle. The first project produced a beam building machine which fabricates aluminum beams suitable for neutral buoyancy evaluation. The second project produced concepts for the lap joint and end cap. However, neither of these joint concepts was suitable for use by a pressure suited crew member in a zero gravity environment. It is concluded that before the beams can be evaluated the joint designs need to be completed and sufficient joints produced to allow assembly of a complex structure.

Pruett, E. C.↗
NASA NTRS1981

A molecular model for ice nucleation and growth, attachment 1

The quantum mechanical technique is used to study ionic, configurational, and impurity defects in the ice surface. In addition to static calculations of the energetics of the water monomer-ice surface interactions, molecular dynamics studies were initiated. The calculations of the monomer-ice surface interaction, molecular dynamics studies were initiated. The calculations of monomer-ice surface interactions indicate that many adsorption sites exist on the ice surfaces and that the barriers between bonding sites are relatively low. Bonding on the prism face of ice is preferentially above lattice sites.

Plummer, P. L. M.↗
NASA NTRS1981

A molecular model for ice nucleation and growth, attachment 2

The central field empirical pair potential model is applied to studying the effects of kinks, ledges, and vacancies on the absorption of water molecules from the vapor. Molecular dynamics simulations indicate that cluster and/or surface modes play a primary role in the absorption process, the flexibility of the hydrogen bond serves to decrease the energy required for structural interconversion, and the rapid distribution of added energy in a hydrogen bonded system lead to aggregate stability which greatly exceeds that predicted by static energy calculations.

Hale, B. N.↗