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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 1,513 records · Page 84
All sourcesNASA NTRSDOE OSTI
NASA NTRS1973

Evaluation of Electrochemical Nitrogen/hydrogen Gas Separator

An electrochemical nitrogen-hydrogen separator subsystem was investigated for use following catalytic dissociation of ammonia or hydrazine in a storage system being considered for long-duration manned space flight. An experimental cell with concentric tubular Pd-25Ag alloy hydrogen diffusion electrodes and hermetically sealed aqueous caustic electrolyte was developed.It was found that this cell operated satisfactorily at 210 C to 245 C and produced dry nitrogen and dry hydrogen with either or both gases at pressures up to 6.8 atmospheres (100 psia) or higher for storage. The final cell developed was operated satisfactorily for 176 days (4200 hours) with no evidence of deterioration of current-voltage performance. The best experimental performance was obtained at 245 C at currents up to 4 amperes (180 ma/sq cm and 360 ma/sq cm anode and cathode current densities, respectively) with a maximum steady-state cell voltage of 0.125 volt for an anode feed of pure hydrogen.

Clifford, J. E.↗
NASA NTRS1975

An experimental documentation of a hypersonic shock-wave turbulent boundary layer interaction flow: With and without separation

An experiment, thoroughly documenting the flow field resulting from the interaction of a shock wave with a nonadiabatic hypersonic turbulent boundary layer, is described. Detailed mean flow and surface data are presented for two shock strengths resulting in attached and separated flows, respectively. The surface measurements include continuous pressure, shear and heat-flux distributions upstream, in, and downstream of the interaction regions. At closely spaced intervals along the surface, boundary-layer profiles of static and pitot pressure and total temperature were obtained from which velocity, density and static temperature profiles were derived. The data are presented in both graphical and tabular form. These data are of sufficient detail to validate advanced computer codes and their associated turbulence models.

Kussoy, M. I.↗
NASA NTRS1975

Separation of the strain components for use in strainrange partitioning

Two methods are presented for separating the inelastic strain components of a complex hysteresis loop so that strainrange partitioning formulas can be applied to accurately determine cyclic life at elevated temperatures. These methods are required only if lower bounds established by strainrange partitioning concepts have been deemed inadequate in the establishment of expected lifetime. In one method, rapid loading and unloading is applied in the tensile and compressive half to isolate the plastic strain. In the second method, the creep is measured at a discrete number of points along the hysteresis loop by combining load-control tests into the general pattern of strain cycling under arbitrary temperature. Both methods are shown to give good results.

Manson, S. S.↗
NASA NTRS1975

Sample detection and analysis techniques for electrophoretic separation

Methods for detecting and analyzing biological agents suitable for space flight operations were studied primarily by literature searches which were conducted of cell separation techniques. Detection methods discussed include: photometrometric, electric, radiometric, micrometry, ultrasonic, microscopic, and photographic. A bibliography, and a directory of vendors are included along with an index of commercial hardware.

Falb, R. D.↗
NASA NTRS1975

Possible application of laser isotope separation

The laser isotope separation process is described and its special economic features discussed. These features are its low cost electric power operation, capital investment costs, and the costs of process materials.

Delionback, L. M.↗
NASA NTRS1975

A hot-wire surface gage for skin friction and separation detection measurements

A heated-element, skin-friction gage employing a very low thermal conductivity support is described. It is shown that the effective dimension of the gage in the stream direction in only 0.06 mm, including the effects of heat conduction in the supporting material. Because of its small size, the calibration of the gage is independent of the kind of boundary-layer flow (whether laminar or turbulent) and is insensitive to pressure gradients. Construction tolerances can be maintained so that a single universal calibration can be applied. Multiple gages, sufficiently closely spaced so as to interfere with each other, are shown to provide accurate determinations of the locations of the points of boundary-layer separation and reattachment.

Rubesin, M. W.↗
NASA NTRS1975

Results of an external tank separation test in AEDC/VKF tunnel B on 0.010-scale replica of space shuttle vehicle model 52-OT(IA17A), Volume 1

Tests were conducted on scale models of the space shuttle orbiter and external tank (ET) to determine the aerodynamic interactions during a return to launch site abort separation. The orbiter model was built to vehicle 3 configuration lines (139B) and the ET model approximated the vehicle 5 configurations with protuberances and attach hardware. For these investigations the orbiter was mounted on the primary support system and the external tank was mounted on the captive trajectory system. Six-component data were obtained for each vehicle at various orbiter angles of attack and sideslip for a range of relative angular and linear displacements of the ET from the orbiter.

Spangler, R. H.↗
NASA NTRS1975

Application of NASTRAN in nonlinear analysis of a cartridge case neck separation malfunction

The problem of case neck separation malfunction in the field of ammunition structural analysis is investigated. The axi-symmetric solid of revolution RING element was utilized in the manual piecewise linear analysis to obtain the expansion of the wall of the cartridge case and barrel chamber by the pressure of propellant gases and the stresses in the structure. The analysis included the varying material properties along the wall of the case and the chamber. Additional instructions were provided to change the element material ID's without recomputing the entire stiffness matrix.

Yang, J. C. S.↗
NASA NTRS1975

A Three-Dimensional Solution of Flows over Wings with Leading-Edge Vortex Separation. Part 1: Engineering Document

A method of predicting forces, moments, and detailed surface pressures on thin, sharp-edged wings with leading-edge vortex separation in incompressible flow is presented. The method employs an inviscid flow model in which the wing and the rolled-up vortex sheets are represented by piecewise, continuous quadratic doublet sheet distributions. The Kutta condition is imposed on all wing edges. Computed results are compared with experimental data and with the predictions of the leading-edge suction analogy for a selected number of wing planforms over a wide range of angle of attack. These comparisons show the method to be very promising, capable of producing not only force predictions, but also accurate predictions of detailed surface pressure distributions, loads, and moments.

Brune, G. W.↗
NASA NTRS1974

A separable fluid connector system effectiveness evaluation technique

An analytical technique is presented for evaluating the relationship among existing numerous separable fluid connector designs to find that configuration which is best (optimal). The data utilized in this research was acquired from approximately 900 flanges designed for six sub-systems of the S-1B stage of the Saturn 1B Space Vehicle. The method is general enough to be useful in optimizing design and systematizing decision-making in a variety of related technical fields.

Prasthofer, W. P.↗
NASA NTRS1975

A three-dimensional solution of flows over wings with leading-edge vortex separation

The application of a new, general, potential flow computational technique to the solution of the subsonic, three-dimensional flow over wings with leading-edge vortex separation is presented. The present method is capable of predicting forces, moments, and detailed surface pressures on thin, sharp-edged wings of rather arbitrary planform. The wing geometry is arbitrary in the sense that leading and trailing edges may be curved or kinked and the wing may have arbitrary camber and twist. The method employs an inviscid flow model in which the wing, the rolled-up vortex sheets, and the wake are represented by piecewise continuous quadratic doublet sheet distributions. The Kutta condition is imposed along all wing edges. Strengths of the doublet distributions as well as shape and position of the free fortex sheet spirals are computed in iterative fashion starting with an assumed initial sheet geometry. The method is verified by numerous computed results.

Weber, J. A.↗
NASA NTRS1974

Meteoritic and volatile elements in Apollo 16 rocks and in separated phases from 14306

Recent evidence from two sources provides a basis for a reexamination of the relationship between the stratigraphy at the Apollo 16 site and the trace element distribution. Information concerning the surface exposure ages makes it possible to relate many samples to specific local impact events. At least five ancient meteoritic components have been tentatively assigned to individual basin-forming impacts on the basis of trace element analyses of Apollo 17 rocks. Attention is given to a petrographic examination of separates from two soils from Station 11 (North Ray Crater).

Ganapathy, R.↗
NASA NTRS1975

Separation of the strain components for use in Strainrange Partitioning

Two methods are presented for separating the inelastic strain components of a complex hysteresis loop so that Strainrange Partitioning formulas can be applied to accurately determine cyclic life at elevated temperatures. These methods are required only if lower bounds established by Strainrange Partitioning concepts have been deemed inadequate in the establishment of expected lifetime. In one method rapid loading and unloading is applied in the tensile and compressive half to isolate the plastic strain. In the second method the 'creep' is measured at a discrete number of points along the hysteresis loop by combining load-control tests into the general pattern of strain cycling under arbitrary temperature. Both methods are shown to give good results.

Manson, S. S.↗
NASA NTRS1976

Integral fan/water separator

Centrifugal force created by rotating fan wheel separates moisture from gas. Lightweight portable unit can be worn with pressurized suit, where it will remove moisture that accumulates from breathing and perspiration.

Johnson, R. L.↗