Search NASA⌕ Search

SEARCH · Search NASA

Results for “PHOTOGRAPHIC APPARATUS”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 91 records · Page 5
All sourcesNASA NTRSDOE OSTI
NASA NTRS1957

A Study of the "toss Factor" in the Impact Testing of Cermets by the Izod Pendulum Test

The test method presented shows that the "toss energy" contributed by the apparatus for brittle materials is negligible. The total toss energy is considered to consist of two components. (a) recovered stored elastic energy and (b) kinetic energy contributed directly by the apparatus. The results were verified by high-speed motion pictures of the test in operation. From these photographs, velocities of tossed specimens were obtained and toss energy computed. In addition, impact energies of some titanium carbide base cermets and high-temperature alloys, as measured by the low-capacity Izod pendulum test, compare well with impact energies measured by the NACA drop test.

ALLOYS, HEAT-RESISTING↗
NASA NTRS1972

Electrophoresis demonstration on Apollo 16

Free fluid electrophoresis, a process used to separate particulate species according to surface charge, size, or shape was suggested as a promising technique to utilize the near zero gravity condition of space. Fluid electrophoresis on earth is disturbed by gravity-induced thermal convection and sedimentation. An apparatus was developed to demonstrate the principle and possible problems of electrophoresis on Apollo 14 and the separation boundary between red and blue dye was photographed in space. The basic operating elements of the Apollo 14 unit were used for a second flight demonstration on Apollo 16. Polystyrene latex particles of two different sizes were used to simulate the electrophoresis of large biological particles. The particle bands in space were extremely stable compared to ground operation because convection in the fluid was negligible. Electrophoresis of the polystyrene latex particle groups according to size was accomplished although electro-osmosis in the flight apparatus prevented the clear separation of two particle bands.

Snyder, R. S.↗
NASA NTRS1990

Foam formation in low gravity

An apparatus that produced the first polyurethane foam in low gravity has been described. The chemicals were mixed together in an apparatus designed for operation in low gravity. Mixing was by means of stirring the chemicals with an electric motor and propeller in a mixing chamber. The apparatus was flown on Consort 1, the first low-gravity materials payload launched by a commercial rocket launch team. The sounding rocket flight produced over 7 min of low gravity during which a polyurethane spheroidal foam of approximately 2300 cu cm was formed. Photographs of the formation of the foam during the flight show the development of the spheroidal form. This begins as a small sphere and grows to approximately a 17-cm-diam spheroid. The apparatus will be flown again on subsequent low-gravity flights.

Wessling, Francis C.↗
NASA NTRS1985

Fundamental Studies of Droplet Combustion at Reduced Gravity

Reduced gravity is used to carry out scientific investigations of droplet combustion. In earlier work a preliminary conceptual design had been developed for droplet burning experiments for Spacelab. Refinements of the earlier work with special consideration given to possible experiments for Mid-Deck Modules of the Space Shuttle is discussed. A re-evaluation of suitable experiments on droplet combustion is done to ascertain whether influences of reduced buoyancy on time-dependent processes of heat and mass transfer in the gas or in the liquid on extinction processes or on disruptive burning phenomena are best suited for further investigation. Components of the experimental apparatus, which include a droplet dispensing system, a droplet positioning system, a droplet ignition system and provision for recording, primarily photographically, the combustion of the individual droplet in a chamber having a controlled gas atmosphere, are studied to determine optimal approaches to the experimental design. Methods for data reduction and interpretation are being made more specific, particularly in the context of an objective to calculate overall gas-phase chemical-kinetic parameters for the combustion from observations of extinction conditions in different atmospheres.

Williams, F. A.↗
NASA NTRS1982

The dryout region in frictionally heated sliding contacts

Some conditions under which boiling and two-phase flow can occur in or near a wet sliding contact are determined and illustrated. The experimental apparatus consisted of a tool pressed against an instrumented slider plate and motion picture sequences at 4000 frames/sec. The temperature and photographic data demonstrated surface conditions of boiling, drying, trapped gas evolution (solutions), and volatility of fluid mixture components. The theoretical modeling and analysis are in reasonable agreement with experimental data.

Hendricks, R. C.↗
NASA NTRS1982

The dryout region in frictionally heated sliding contacts

Some conditions under which boiling and two-phase flow can occur in or near a wet sliding contact are determined and illustrated. The experimental apparatus consisted of a tool pressed against an instrumented slider plate and motion picture sequences at 4000 frames/sec. The temperature and photographic data demonstated surface conditions of boiling, dry, trapped gas evolution (solutions), and volatility of fluid mixture components. The theoretical modeling and analysi are in reasonable agreement with experimental data. Previously announced in STAR as N82-28574

Hendricks, R. C.↗
NASA NTRS1944

Preknock Vibrations in a Spark-Ignition Engine Cylinder as Revealed by High-Speed Photography

The high-speed photographic investigation of the mechanics of spark-ignition engine knock recorded in three previous reports has been extended with use of the NACA high-speed camera and combustion apparatus with a piezoelectric pressure pickup in the combustion chamber. The motion pictures of knocking combustion were taken at the rate of 40,000 frames per second. Existence of the preknock vibrations in the engine cylinder suggested in Technical Report no.727 has been definitely proved and the vibrations have been analyzed both in the high-speed motion pictures and the pressure traces. Data are also included to show that the preknock vibrations do not progressively build up to cause knock. The effect of tetraethyl lead on the preknock vibrations has been studied and results of the tests are presented. Photographs are presented which in some cases clearly show evidence of autoignition in the end zone a considerable length of time before knock occurs.

Miller, Cearcy D↗
NASA NTRS1937

A Preliminary Study of Flame Propagation in a Spark-ignition Engine

The N.A.C.A. combustion apparatus was altered to operate as a fuel-injection, spark-ignition engine, and a preliminary study was made of the combustion of gasoline-air mixtures at various air-fuel ratios. Air-fuel ratios ranging from 10 to 21.6 were investigated. Records from an optical indicator and films from a high-speed motion-picture camera were the chief sources of data. Schlieren photography was used for an additional study. The results show that the altered combustion apparatus has characteristics similar to those of a conventional spark-ignition engine and should be useful in studying phenomena in spark-ignition engines. The photographs show the flame front to be irregularly shaped rather than uniformly curved. With a theoretically correct mixture the reaction, as indicated by the photographs, is not completed in the flame front but continues for some time after the combustion front has traversed the mixture.

Rothrock, A M↗
NASA NTRS1977

TV fatigue crack monitoring system

An apparatus is disclosed for monitoring the development and growth of fatigue cracks in a test specimen subjected to a pulsating tensile load. A plurality of television cameras photograph a test specimen which is illuminated at the point of maximum tensile stress. The television cameras have a modified vidicon tube which has an increased persistence time thereby eliminating flicker in the displayed images.

Exton, R. J.↗
NASA NTRS1985

Flammability Limits of Gases Under Low Gravity Conditions

The purpose of this combustion science investigation is to determine the effect of zero, fractional, and super gravity on the flammability limits of a premixed methane air flame in a standard 51 mm diameter flammability tube and to determine, if possible, the fluid flow associated with flame passage under zero-g conditions and the density (and hence, temperature) profiles associated with the flame under conditions of incipient extinction. This is accomplished by constructing an appropriate apparatus for placement in NASA's Lewis Research Center Lear Jet facility and flying the prescribed g-trajectories while the experiment is being performed. Data is recorded photographically using the visible light of the flame. The data acquired is: (1) the shape and propagation velocity of the flame under various g-conditions for methane compositions that are inside the flammable limits, and (2) the effect of gravity on the limits. Real time accelerometer readings for the three orthogonal directions are displayed in full view of the cameras and the framing rate of the cameras is used to measure velocities.

Strehlow, R. A.↗
NASA NTRS1988

A facility for precise temperature control applications in microgravity

The general design, main components, and operation of the isothermal dendritic growth apparatus (IDGA) designed for microgravity experimentation are described. The four major subsystems of the IDGA are a temperature controlled thermostatic bath capable of milli-kelvin stability, a photographic data collection system, a crystal growth chamber, and a growth detection system to initiate data collection. Some of the specific experiments that could utilize the capabilities of the IDGA are dendritic growth in alloys, monotectic systems, life science experiments, and technological applications.

Glicksman, M. E.↗
NASA NTRS1979

Burn-test apparatus for fiber composites

Burn-test apparatus made from conductive metal grid and indicator lamp monitors release of conductive carbon fibers from specimen of carbon-reinforced composites exposed to flame. Procedure is more sensitive than photographing or physically trapping and counting fibers.

Dowler, W. L.↗
NASA NTRS1988

Dynamic shear of granular material under variable gravity conditions

This paper describes some experiments with granular materials which recently have been conducted aboard the NASA KC-135 aircraft during variable gravity maneuvers. The main experimental apparatus consisted of a small drum containing granular material which was rotated slowly while the angle assumed by the slip surface with respect to the horizontal was observed and recorded photographically. Conventional wisdom has held that this 'dynamic angle of response' was a material constant, independent of (among other things) gravitational level. The results presented here are quite contrary, suggesting instead an angle that varies with the reciprocal of the square root of gravity. This finding may have important consequences on the understanding of many active processes in Planetary Geology involving granular materials and may provide qualitative confirmation of some of the theoretical predictions of modern models of granular shear flows.

White, B. R.↗
NASA NTRS1987

Photorefractor ocular screening system

A method and apparatus for detecting human eye defects, particularly detection of refractive error is presented. Eye reflex is recorded on color film when the eyes are exposed to a flash of light. The photographs are compared with predetermined standards to detect eye defects. The base structure of the ocular screening system is a folding interconnect structure, comprising hinged sections. Attached to one end of the structure is a head positioning station which comprises vertical support, a head positioning bracket having one end attached to the top of the support, and two head positioning lamps to verify precise head positioning. At the opposite end of the interconnect structure is a camera station with camera, electronic flash unit, and blinking fixation lamp, for photographing the eyes of persons being evaluated.

Richardson, John R.↗
NASA NTRS1988

Test Apparatus For Oversize Ball-Bearing Models

See-through machine enables direct observation and indirect measurements at moderate speeds. Model of ball bearing, six times larger than real bearing, rotated in test machine. Transparency of walls and simulated lubricant reveal flow patterns and allow visible-light and infrared photographs to be made.

Wagner, William R.↗
NASA NTRS1987

Incident meteoroid flux density

Complex photographic and radar meteor observations were carried out. Using the available observational data, the density of incident flux of meteoroids was estimated over a wide mass range of 0.001 to 100 g. To avoid the influence of apparatus selectivity a special technique was applied. The main characteristics of this technique are given and discussed.

Badadjanov, P. B.↗
NASA NTRS1992

Lubricant evaluation of the alpha and beta joints, phase 2

A research study was conducted to evaluate dry film lubrication of long life space components such as the alpha and beta joints of the Space Station. The problem addressed in the report pertains to the longevity of sputtered MoS2 or ion plated lead films in a rolling contact environment. A special technique was devised for the experiments, which incorporated a coated ball cyclically loaded against a flat plate. At fixed intervals the surface of the coating was photographed at 100X magnification. By computer scanning the photographs, the rate of coating loss was determined. Experimental variables include load and surface finish of the plate. A theory was developed to analyze the state of stress between ball and flat. The stress condition in the ball apparatus was related to the state of stress under rolling contact conditions. Based on the experiments life appeared to decrease with increasing load and increasing surface roughness. An ion plated lead film gave better life than a sputtered MoS2 film. However, by keeping the interfacial shear stress at a low level, adequate coating life was achieved for either coating. For the lead film, the critical stress was about 0.19 GPa (28 ksi). The study dealt only with mechanical wear. Before a coating is selected for a critical space application, other factors such as reaction with atomic oxygen must also be considered.

Kannel, J. W.↗