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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 19 records

Nomograph for prediction of RF-breakdown voltages

Information in nomograph is derived from data obtained from RF-breakdown tests on components of uniform and nonuniform geometry. Nomograph also can be used in design work to predict breakdown margins; if operational minimum pressure is established giving minimum value on nomograph, minimum breakdown voltage consistent with allowed value can be predicted.

Hickernell, F. S.↗

Richardson-Dushman equation nomograph

Nomographic Richardson-Dushman equation solutions for thermionic electron emission devices, giving current density for various work functions and electrode temperatures

Breitwieser, R.↗

Nomographic Solution of the Momentum Equation for VTOL-STOL Aircraft

VTOL-STOL aircraft are characterized in general by the fact that in some portion of their flight envelope the wake is sharply inclined to the free stream. Under such conditions, the usual small-angle assumptions used in determining the induced velocities, and consequently, the power required, are no longer valid. Indeed, the use of small-angle assumptions leads to such anomalous results as infinite induced velocities and required power in the extreme case of hovering. The aforementioned difficulties may be avoided by a more complete examination of the horizontal and vertical momentum imparted to the air by the aircraft at low speeds. The resulting equation is a quartic in the induced velocity, and, as such, is difficult to apply. On the other hand, this quartic can be solved in its most general terms and the resulting solution then can be derived and presented in the form of a chart, or nomograph, from which the required induced velocities my be read directly. This paper presents such a chart.

Heyson, Harry H.↗

A Nomographic Methodology for Use in Performance Trade-Off Studies of Parabolic Dish Solar Power Modules

A simple graphical method was developed to undertake technical design trade-off studies for individual parabolic dish models comprising a two-axis tracking parabolic dish with a cavity receiver and power conversion assembly at the focal point. The results of these technical studies are then used in performing the techno-economic analyses required for determining appropriate subsystem sizing. Selected graphs that characterize the performance of subsystems within the module were arranged in the form of a nomogram that would enable an investigator to carry out several design trade-off studies. Key performance parameters encompassed in the nomogram include receiver losses, intercept factor, engine rating, and engine efficiency. Design and operation parameters such as concentrator size, receiver type (open or windowed aperture), receiver aperture size, operating temperature of the receiver and engine, engine partial load characteristics, concentrator slope error, and the type of reflector surface, are also included in the graphical solution. Cost considerations are not included.

Selcuk, M. K.↗

Helicopter rotor wake geometry and its influence in forward flight. Volume 2: Wake geometry charts

Isometric and projection view plots, inflow ratio nomographs, undistorted axial displacement nomographs, undistorted longitudinal and lateral coordinates, generalized axial distortion nomographs, blade/vortex passage charts, blade/vortex intersection angle nomographs, and fore and aft wake boundary charts are discussed. Example condition, in flow ratio, undistorted axial location, longitudinal and lateral coordinates, axial coordinates distortions, blade/tip vortex intersections, angle of intersection, and fore and aft wake boundaries are also discussed.

Egolf, T. A.↗

Statistical determination of space shuttle component dynamic magnification factors

A method is presented of obtaining vibration design loads for components and brackets. Dynamic Magnification Factors from applicable Saturn/Apollo qualification, reliability, and vibroacoustic tests have been statistically formulated into design nomographs. These design nomographs have been developed for different component and bracket types, mounted on backup structure or rigidly mounted and excited by sinusoidal or random inputs. Typical nomographs are shown.

Lehner, F.↗

AP-8 trapped proton environment for solar maximum and solar minimum

Data sets from Ov-3 and Azur indicate a need for improvement in models of the stably trapped proton flux with energies between 0.1 and 400 MeV. Two computer accessible models are described: AP8MAX and AP8MIN. The models are presented in the form of nomographs, B-L plots, R-lambda plots, and equatorial radial profiles. Nomographs of the orbit-integrated fluxes are also discussed. The models are compared with each other, with the data, and with previous AP models. Requirements for future improvements include more complete data coverage and periodic comparisons with new data sets as they become available. The machine-sensible format in which the models are available are described.

Sawyer, D. M.↗

Debris/ice/TPS assessment and photographic analysis for Shuttle Mission STS-28R

A Debris/Ice/TPS assessment and photographic analysis was conducted for Space Shuttle Mission STS-28R. Debris inspections of the flight elements and launch pad are performed before and after launch. Ice/Frost conditions on the External Tank are assessed by the use of computer programs, nomographs, and infrared scanner data during cryogenic loading of the nomographs, and infrared scanner data during cryogenic loading of the vehicle followed by on-pad visual inspection. High speed photography is analyzed after launch to identify ice/debris sources and evaluate potential vehicle damage and/or in-flight anomalies. The debris/ice/TPS conditions and photographic analysis of Mission STS-28R is documented along with their overall effect on the Space Shuttle Program.

Stevenson, Charles G.↗

Device accurately measures and records low gas-flow rates

Free-floating piston in a vertical column accurately measures and records low gas-flow rates. The system may be calibrated, using an adjustable flow-rate gas supply, a low pressure gage, and a sequence recorder. From the calibration rates, a nomograph may be made for easy reduction. Temperature correction may be added for further accuracy.

Branum, L. W.↗

Spectrofluorometer techniques applicable to sample surfaces

Methods for correcting fluorescence spectra to remove instrumental artifacts are described, including computational and graphical procedures for rapid manual correction by nomographs and similar techniques. Expedient methods for the selection and use of optical filters, the evaluation of filter effectiveness, and the selection of optimum wavelength settings in spectrofluorometry are outlined.

Stoertz, G. E.↗

Program management aid for redundancy selection and operational guidelines

Although this criterion was developed specifically for use on the shuttle program, it has application to many other multi-missions programs (i.e. aircraft or mechanisms). The methodology employed is directly applicable even if the tools (nomographs and equations) are for mission peculiar cases. The redundancy selection criterion was developed to insure that both the design and operational cost impacts (life cycle costs) were considered in the selection of the quantity of operational redundancy. These tools were developed as aids in expediting the decision process and not intended as the automatic decision maker. This approach to redundancy selection is unique in that it enables a pseudo systems analysis to be performed on an equipment basis without waiting for all designs to be hardened.

Hodge, P. W.↗

Possibility of saturnian synchrotron radiation

Synchrotron spectra were computed for a hypothetical Saturn radiation belt. A monoenergetic distribution of relativistic electrons was assumed to exist in a toroidal volume in a dipole magnetic field aligned with the rotation axis. When synchrotron emission is added to the thermal component implied by observations at wavelengths shorter than 50 cm, the upturn in the total emission spectrum may be gradual to sharp, depending on the critical wavelength and the number density of radiating electrons. With the constraint of the pressure balance equation, the ranges of magnetic field intensity, and electron energy, and density were tabulated and nomographically illustrated. For several estimates of the magnetic field loading factor, the minimum surface magnetic field intensity and minimum electron number density were computed.

Luthey, J. L.↗