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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 595 records · Page 33
All sourcesNASA NTRSDOE OSTI
NASA NTRS1974

Rock elastic properties and near-surface structure at Taurus-Littrow

Linear strain measurements are presented for two lunar basalts, 14310,82 and 71055,15 and one breccia, 15498,23 to 5 kb hydrostatic pressure. Compressional and shear acoustic velocities to 5 kb are also presented for the basalts, 14310,82 and 71055,15. These elastic properties, along with geological, seismological and rock mechanics considerations are consistent with a model of the structure of the Taurus-Littrow valley as follows, a thin surface regolith overlying a fractured mixture of basalt flows and ejecta material which in turn overlies a coherent breccia of highland ejecta debris.

Trice, R.↗
NASA NTRS1975

Ispra Mark-10 water splitting process

A thermochemical water splitting process, the Ispra Mark-10 chemical reaction cycle, was chosen for examining the possibility of using water to produce hydrogen on a large scale for fuel and major industrial chemical uses. The assumed energy source for the process is an HTGR (helium cooled). A process flow diagram, a material balance, and an energy balance were developed for the thermochemical reaction cycle. Principal reactions which constitute the cycle are included.

Source record↗
NASA NTRS1976

Noise generated by quiet engine fans. 3: Fan C

A family of fans designed with low noise features was acoustically evaluated, and noise results are documented for a 1.6-pressure-ratio, 472-m/sec (155-ft/sec) tip speed fan. The fan is described and some aerodynamic operating data are given. Far field noise around the fan was measured over a range of operating conditions for a variety of configurations having different arrangements of sound absorbing material in the flow ducts. Complete results of 1.3 octave band analysis of the data are presented in tabular form. Included also are acoustic power spectra and sideline perceived noise levels. Representative 1/3 octave band data are presented graphically, and sample graphs of continuous narrow band spectra are also provided.

Montegan, F. J.↗
NASA NTRS1977

Friction factor for isothermal and nonisothermal flow through porous media

Measurements were performed to determine the pressure drops for gaseous flow through porous materials of different microstructures, porosities, and thickness under isothermal and nonisothermal conditions at various temperature levels. Results were satisfactorily correlated by a simple equation relating the friction factor to the Reynolds number and porosities.

Koh, J. C.↗
NASA NTRS1978

Computer model for refinery operations with emphasis on jet fuel production. Volume 2: Data and technical bases

The FORTRAN computing program predicts the flow streams and material, energy, and economic balances of a typical petroleum refinery, with particular emphasis on production of aviation turbine fuel of varying end point and hydrogen content specifications. The program has provision for shale oil and coal oil in addition to petroleum crudes. A case study feature permits dependent cases to be run for parametric or optimization studies by input of only the variables which are changed from the base case. The report has sufficient detail for the information of most readers.

Dunbar, D. N.↗
NASA NTRS1978

Computer model for refinery operations with emphasis on jet fuel production. Volume 1: Program description

A FORTRAN computer program is described for predicting the flow streams and material, energy, and economic balances of a typical petroleum refinery, with particular emphasis on production of aviation turbine fuel of varying end point and hydrogen content specifications. The program has provision for shale oil and coal oil in addition to petroleum crudes. A case study feature permits dependent cases to be run for parametric or optimization studies by input of only the variables which are changed from the base case.

Dunbar, D. N.↗
NASA NTRS1978

Computer model for refinery operations with emphasis on jet fuel production. Volume 3: Detailed systems and programming documentation

The FORTRAN computing program predicts flow streams and material, energy, and economic balances of a typical petroleum refinery, with particular emphasis on production of aviation turbine fuels of varying end point and hydrogen content specifications. The program has a provision for shale oil and coal oil in addition to petroleum crudes. A case study feature permits dependent cases to be run for parametric or optimization studies by input of only the variables which are changed from the base case.

Dunbar, D. N.↗
NASA NTRS1978

CTOL Transport Technology, 1978

Technology generated by NASA and specifically associated with advanced conventional takeoff and landing transport aircraft is reported. Topics covered include: aircraft propulsion; structures and materials; and laminar flow control.

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NASA NTRS1980

A feasibility study for advanced technology integration for general aviation

An investigation was conducted to identify candidate technologies and specific developments which offer greatest promise for improving safety, fuel efficiency, performance, and utility of general aviation airplanes. Interviews were conducted with general aviation airframe and systems manufacturers and NASA research centers. The following technologies were evaluated for use in airplane design tradeoff studies conducted during the study: avionics, aerodynamics, configurations, structures, flight controls, and propulsion. Based on industry interviews and design tradeoff studies, several recommendations were made for further high payoff research. The most attractive technologies for use by the general aviation industry appear to be advanced engines, composite materials, natural laminar flow airfoils, and advanced integrated avionics systems. The integration of these technologies in airplane design can yield significant increases in speeds, ranges, and payloads over present aircraft with 40 percent to 50 percent reductions in fuel used.

Kohlman, D. L.↗
NASA NTRS1981

The cooling and condensation of flare coronal plasma

A model is investigated for the decay of flare heated coronal loops in which rapid radiative cooling at the loop base creates strong pressure gradients which, in turn, generate large (supersonic) downward flows. The coronal material cools and 'condenses' onto the flare chromosphere. The features which distinguish this model from previous models of flare cooling are: (1) most of the thermal energy of the coronal plasma may be lost by mass motion rather than by conduction or coronal radiation; (2) flare loops are not isobaric during their decay phase, and large downward velocities are present near the footpoints; (3) the differential emission measure q has a strong temperature dependence.

Antiochos, S. K.↗
NASA NTRS1981

Icing tunnel tests of a glycol-exuding porous leading edge ice protection system on a general aviation airfoil

Tests were conducted in the Icing Research Tunnel at the NASA Lewis Research Center to determine the characteristics of an ice protection system that distributes a glycol solution onto the leading edge of an airfoil through a porous surface material. Minimum fluid flow rates required to achieve anti-icing (no ice formation) were determined for various flight conditions and angles of attack. The ability of the system to remove ice formed on the airfoil before system activation was also investigated.

Kohlman, D. L.↗
NASA NTRS1981

Silicon production process evaluations

Chemical engineering analysis of the HSC process (Hemlock Semiconductor Corporation) for producing silicon from dichlorosilane in a 1,000 MT/yr plant was continued. Progress and status for the chemical engineering analysis of the HSC process are reported for the primary process design engineering activities: base case conditions (85%), reaction chemistry (85%), process flow diagram (60%), material balance (60%), energy balance (30%), property data (30%), equipment design (20%) and major equipment list (10%). Engineering design of the initial distillation column (D-01, stripper column) in the process was initiated. The function of the distillation column is to remove volatile gases (such as hydrogen and nitrogen) which are dissolved in liquid chlorosilanes. Initial specifications and results for the distillation column design are reported including the variation of tray requirements (equilibrium stages) with reflux ratio for the distillation.

Source record↗
NASA NTRS1982

Silicon production process evaluations

Chemical engineering analysis was continued for the HSC process (Hemlock Semiconductor Corporation) in which solar cell silicon is produced in a 1,000 MT/yr plant. Progress and status are reported for the primary engineering activities involved in the preliminary process engineering design of the plant base case conditions (96%), reaction chemistry (96%), process flow diagram (85%), material balance (85%), energy balance (60%), property data (60%), equipment design (40%), major equipment list (30%) and labor requirements (10%). Engineering design of the second distillation column (D-02, TCS column) in the process was completed. The design is based on a 97% recovery of the light key (TCS, trichlorosilane) in the distillate and a 97% recovery of the heavy key (TET, silicon tetrachloride) in the bottoms. At a reflux ratio of 2, the specified recovery of TCS and TET is achieved with 20 trays (equilibrium stages, N=20). Respective feed tray locations are 9, 12 and 15 (NF sub 1 = 9, NF sub 2 = 12,, and NF sub 3 = 15). A total condenser is used for the distillation which is conducted at a pressure of 90 psia.

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NASA NTRS1982

Interim review of the Energy Efficient Engine /E3/ Program

The NASA-sponsored Energy Efficient Engine (E3) Program, which is now in its fourth year, is assessed from the viewpoint of one of its research contractors. Attention is given to the development status of the shroudless fan, segmented combustor and exhaust mixer components which are encompassed by the program. The shroudless fan blades are two-thirds hollow for lightness, and are fabricated by means of plies and cores subjected to hot isostatic pressing diffusion bonding. The combustor's segmented liner is cast from turbine blade materials. Exhaust mixer flow visualization tests are described. Consideration is given to the effects of integrating the technology described with the low and high pressure advanced turbines whose development is also part of the E3 program.

Gardner, W. B.↗
NASA NTRS1983

Observations of neutral hydrogen in radio-loud and interacting galaxies

The results of a survey of H I in radio-loud and interacting galaxies is presented. Four cases of H I absorption and five of emission are reported. The interesting features found for individual galaxies are described, and the systematic properties are discussed. Column densities of absorbing gas generally exceed those expected for a 'Milky Way' H I disk by more than an order of magnitude. The absorbing gas must have a flattened, disklike morphology oriented roughly parallel to the optical disk of the galaxy. Turbulent noncircular gas motions are evidently present, which are shown to be almost certainly induced by galaxy-galaxy interactions. The set of galaxies in which H I absorption has been detected is dominated by morphologically peculiar objects. It is concluded that the detection of H I seen in absorption against a nuclear radio source permits direct determination of the sense of radial flow of extranuclear material, and is direct evidence that potential 'food' for a compact object in the nucleus exists in the galaxy.

Heckman, T. M.↗
NASA NTRS1984

Tensile Fracture of Ductile Materials

For brittle materials, circular voids play an important role relative to fracture, intensifing both tensile and compressive stresses. A maximum intensified tensile stress failure criterion applies quite well to brittle materials. An attempt was made to explore the possibility of extending the approach to the tensile fracture of ductile materials. The three dimensional voids that exist in reality are modelled by circular holes in sheet metal. Mathematical relationships are sought between the shape and size of the hole, after the material is plastically deformed, and the amount of deformation induced. Then, the effect of hole shape, size and orientation on the mechanical properties is considered experimentally. The presence of the voids does not affect the ultimate tensile strength of the ductile materials because plastic flow wipes out the stress intensification caused by them. However, the shape and orientation of the defect is found to play an important role in affecting the strain at fracture.

Pai, D. M.↗
NASA NTRS1985

Shaft Seal Compensates for Cold Flow

Seal components easy to install. Ring seal for rotating or reciprocating shafts spring-loaded to compensate for slow yielding (cold flow) of sealing material. New seal relatively easy to install because components preassembled, then installed in one piece.

Myers, W. N.↗
NASA NTRS1985

Seyfert galaxy narrow-line regions. II - Kinematic models

A class of kinematic models for the narrow-line regions of active galactic nuclei is presented. The models incorporate continuity-constrained radial flow of emitting material in a bounded, spherical geometry. They are designed to represent the narrow-line regions in as simple a manner as is consistent with current knowledge. The systematic comparison of line profiles arising from the models to the spectra in the forbidden O III lambda 5007 emission line which have been described in Paper I of this series is used as a probe of the line-emitting region kinematics: the model parameter areas of interest are identified and tested for consistency with the data. The results indicate heterogeneous kinematic conditions; the most common pattern is outflow of emitting material in a radially decelerating velocity field in the presence of distributed obscuration. However, some observed line profiles can be fitted by several model profiles from very different kinematic conditions, indicating that the information in a spatially unresolved line profile is insufficient to constrain uniquely the geometry and kinematics of the line-emitting region. Although the specific conclusions are model dependent, a predominantly radial pattern of velocities and a distribution of obscuring material are probably essential features of any successful kinematic model of the narrow-line regions.

Vrtilek, J. M.↗