SEARCH · Search NASA

Results for “Redirect”

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.

SourceResearch connectionFrom yearThrough year

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

At least 145 records · Page 8

All sources NASA NTRS DOE OSTI

NASA NTRS1979

New energy conversion techniques in space, applicable to propulsion

The powering of aircraft with laser energy from a solar power satellite may be a promising new approach to the critical problem of the rising cost of fuel for aircraft transportation systems. The result is a nearly fuelless, pollution-free flight transportation system which is cost-competitive with the fuel-conservative airplane of the future. The major components of this flight system include a laser power satellite, relay satellites, laser-powered turbofans and a conventional airframe. The relay satellites are orbiting optical systems which intercept the beam from a power satellite and refocus and redirect the beam to its next target.

Hertzberg, A.↗

NASA NTRS1980

New mounting improves solar-cell efficiency

Method boosts output by about 20 percent by trapping and redirecting solar radiation without increasing module depth. Mounted solar-cell array is covered with internally reflecting plate. Plate is attached to each cell by transparent adhesive, and space between cells is covered with layer of diffusely reflecting material. Solar energy falling on space between cells is diffused and reflected internally by plate until it is reflected onto solar cell.

Shepard, N. F., Jr.↗

NASA NTRS1980

Changes in erythropoietin levels during space flight or space flight simulation

Two hundred and seventy samples from 24 subjects involved in 3 bedrest studies and from 3 subjects involved in Spacelab Mission Development Test 3 were assayed for erythropoietin (Ep), in an in vitro fetal mouse liver cell assay, and for ferritin using a commercially available immunoradiometric assay kit. No trends or significant changes in serum Ep were observed. Serum ferritin concentrations tended to increases slightly during the 'missions', reflecting a redirection of iron from the suppressed erythron into iron stores.

Dunn, C. D. R.↗

NASA NTRS1981

Hoop/column antenna technology development summary

The Langley Research program for development of hoop/column antenna technology was redirected and includes the fabrication and test of models such as the 4 gore segment of a 50 meter antenna and the 15 meter diameter fully deployable antenna. Significant results were obtained in the point design that includes a quad aperture reflector system for multiple beam applications.

Campbell, T. G.↗

NASA NTRS1981

Solar Brayton engine/alternator set

Work on the Mod O solar Brayton engine/alternator set is redirected to utilize solarized components of the automotive advanced gas turbine (AGT). The new configuration is referred to as the Mod I. Commercialization of solar Brayton engines thus should be enhanced not only by relating the design to an engine expected to reach the high quantity, low cost production rates associated with the automotive market, but also by the potential the AGT components provide for growth of efficiency and power rating. This growth would be achieved through use of ceramics in later versions making operation possible at temperatures up to 2500 F. The longer program duration and higher cost of the Mod I is considered.

Six, L.↗

NASA NTRS1982

Reflective-Shield Radiative Cooler

Tests show radiative cooler consisting of several thin reflective shields with a slight angle between them redirects flow of heat very effectively. Shield can be used for deflecting virtually any level of thermal radiation can be deflected by technique; but it may be useful in construction reflecting baffles in front of ovens or furnaces.

Petrick, W.↗

NASA NTRS1981

Determination of wind tunnel constraint effects by a unified pressure signature method. Part 2: Application to jet-in-crossflow

The development of an improved jet-in-crossflow model for estimating wind tunnel blockage and angle-of-attack interference is described. Experiments showed that the simpler existing models fall seriously short of representing far-field flows properly. A new, vortex-source-doublet (VSD) model was therefore developed which employs curved trajectories and experimentally-based singularity strengths. The new model is consistent with existing and new experimental data and it predicts tunnel wall (i.e. far-field) pressures properly. It is implemented as a preprocessor to the wall-pressure-signature-based tunnel interference predictor. The supporting experiments and theoretical studies revealed some new results. Comparative flow field measurements with 1-inch "free-air" and 3-inch impinging jets showed that vortex penetration into the flow, in diameters, was almost unaltered until 'hard' impingement occurred. In modeling impinging cases, a 'plume redirection' term was introduced which is apparently absent in previous models. The effects of this term were found to be very significant.

Hackett, J. E.↗

NASA NTRS1982

High frequency sound emission from moving point multipole sources embedded in arbitrary transversely sheared mean flows

Formulas are derived for the high frequency sound emission from moving point multipole sources embedded in an arbitrary unidirectional transversely sheared mean flow. The results are used to study the sound generated by non-axisymmetric turbulent jets. The effect of the asymmetry in both the mean flow and the source distribution is accounted for by a 'circumferential directivity factor', which is easily calculated from the solution of a second order ordinary differential equation in the general case and from an explicit formula when the mean flow is symmetric but the source location is not. This factor is used to assess the potential of employing asymmetric velocity profiles that redirect the sound upward to reduce the noise radiation below the flight path of a jet aircraft.

Goldstein, M. E.↗

NASA NTRS1982

Sky input horn for a far-infrared interferometer

A unique design has been developed whereby a compound parabolic concentrator (CPC) and a compound elliptical concentrator (CEC) are joined at their throats. The CPC serves as the field-defining optics, in that it accepts up to a certain maximum acceptance angle and then concentrates this accepted energy at its throat. Energy incident from angles greater than the acceptance angle is rejected. The CEC takes the energy concentrated at the CPC throat and then redirects this energy into a finite-sized pupil a given distance away. The considered design will be used as the sky input horn for a cryogenic far-infrared polarizing interferometer to be flown on NASA's Cosmic Background Explorer satellite. The interferometer will operate at 2 K and measure the 3-K cosmic background radiation of the universe in the 100-micrometer-1-cm spectral range.

Miller, M. S.↗

NASA NTRS1982

Double layer formation during current sheet disruptions in a reconnection experiment

When the current density in the center of a neutral sheet is increased to a critical value spontaneous current disruptions are observed. The release of stored magnetic field energy results in a large inductive voltage pulse which drops off inside the plasma in the form of a potential double layer. Particles are energized, microinstabilities are generated, the plasma is thinned, and the current flow is redirected. These laboratory observations qualitatively support recent models of magnetic substorms and solar flares.

Stenzel, R. L.↗

NASA NTRS1982

FSAs future role

The latest thinking about how the Flat-Plate Solar Array Project (FSA), will redirect activities away from recent product-oriented technology development efforts and toward longer-term research on technical problems that could limit future large-scale use of photovoltaics is addressed. With the emphasis on research, the Project is now organizing a series of workshops addressing the key basic technological questions by specific topic. Intervals between Project Integration Meetings are being extended because there are fewer contracts within ESA and because work under those contracts has been attenuated.

Callaghan, W. T.↗

NASA NTRS1983

A Study of Production of Miscibility Gap Alloys with Controlled Structures

Composite materials were directionally solidified using a new technique to align the constituents longitudinally along the length of the specimen. In some instances a tin coating was applied and diffused into the sample to form a high transition temperature superconducting phase. The superconducting properties were measured and compared with the properties obtained for powder composites and re-directionally solidified powder compacts. The samples which were compacted and redirectionally solidified showed the highest transition temperature and wildest transition range. This indicates that both steps, powder compaction and resolidification, determine the final superconducting properties of the material.

Parr, R. A.↗

NASA NTRS1983

A compact inflow control device for simulating flight fan noise

Inflow control device (ICD's) of various shapes and sizes have been used to simulate inflight fan tone noise during ground static tests. A small, simple inexpensive ICD design was optimized from previous design and fabrication techniques. This compact two-fan-diameter ICD exhibits satisfactory acoustic performance characteristics without causing noise attenuation or redirection. In addition, it generates no important new noise sources. Design and construction details of the compact ICD are discussed and acoustic performance test results are presented.

Homyak, L.↗

NASA NTRS1983

A compact inflow control device for simulating flight fan noise

Homyak, L.↗

NASA NTRS1982

Low-cost solar array progress and plans

It is pointed out that significant redirection has occurred in the U.S. Department of Energy (DOE) Photovoltaics Program, and thus in the Flat-Plate Solar Array Project (FSA), since the 3rd European Communities Conference. The Silicon Materials Task has now the objective to sponsor theoretical and experimental research on silicon material refinement technology suitable for photovoltaic flat-plate solar arrays. With respect to the hydrochlorination reaction, a process proof of concept was completed through definition of reaction kinetics, catalyst, and reaction characteristics. In connection with the dichlorosilane chemical vapor desposition process, a preliminary design was completed of an experimental process system development unit with a capacity of 100 to 200 MT/yr of Si.Attention is also given to the silicon-sheet formation research area, environmental isolation research, the cell and module formation task, the engineering sciences area, and the module performance and failure analysis area.

Callaghan, W. T.↗

NASA NTRS1983

ISEE-3 - A late entry in the great comet chase

The ISEE-3 spacecraft, currently in a figure-8 traverse of the geomagnetic tail between 80-220 earth radii, is being redirected to a flyby of the Giacobini-Zinner comet in 1985. The satellite carries experiments for the solar wind plasma, magnetic field data, plasma wave and composition, radio waves, and energetic protons, and can gather data on the solar wind-comet interaction. A double lunar swingby will be employed to establish the intercept trajectory, yielding a total velocity change of 100 m/sec, with a reserve of 100 m/sec for midcourse corrections. The comet will be encountered at a distance of 3000 km in September 1985, followed by passage through the Halley's comet tail 5000 km from the nucleus in March 1986.

Farquhar, R.↗

NASA NTRS1984

Radiative cooler

A method and radiative cooling device for use in passively cooling spaces is described. It is applicable to any level of thermal radiation in vacuum and to high-intensity thermal radiation in non-vacuum environments. The device includes an enclosure nested in a multiplicity of thin, low-emittance, highly-reflective shields. The shields are suspended in a casing in mutual angular relation and having V-shaped spaces defined therebetween for redirecting, by reflection, toward the large openings of the V-shaped spaces, thermal radiation entering the sides of the shields, and emitted to the spaces, whereby successively reduced quantities of thermal radiation are reflected by the surfaces along substantially parallel paths extended through the V-shaped spaces to a common heat sink such as the cold thermal background of space.

Petrick, S. W.↗

NASA NTRS1982

Calculation of rotor/airframe interference for realistic configurations

The results of a fully coupled calculation of the flow around representative helicopter configurations are presented. The effect of fuselage components on the rotor flowfield and the overall wake structure is detailed and the aerodynamic interference between the different parts of the aircraft is discussed. In particular, the flowfield developed by the rotor head is followed and the effect of a rotor head cap and pylon modifications in redirecting the rotor head flow are illustrated. Good correlation between measured and calculated fuselage airloads in low-speed flight is achieved and correspondence with observed flowfield behavior is demonstrated.

Clark, D. R.↗