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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 415 records · Page 23
All sourcesNASA NTRSDOE OSTI
NASA NTRS1971

Long-duration exercise at moderate work loads

Metabolic effects of long duration exercise at moderate work loads including tables of heart rate, rectal temperature, minute volume, water balance, and respiratory quotient

Camacho, A.↗
NASA NTRS1972

The interaction of moderately strong shock waves with thick perforated walls of low porosity

A theoretical prediction is given of the flow through thick perforated walls of low porosity resulting from the impingement of a moderately strong traveling shock wave. The model was a flat plate positioned normal to the direction of the flow. Holes bored in the plate parallel to the direction of the flow provided nominal hole length-to-diameter ratios of 10:1 and an axial porosity of 25 percent of the flow channel cross section. The flow field behind the reflected shock wave was assumed to behave as a reservoir producing a quasi-steady duct flow through the model. Rayleigh and Fanno duct flow theoretical computations for each of three possible auxiliary wave patterns that can be associated with the transmitted shock (to satisfy contact surface compatibility) were used to provide bounding solutions as an alternative to the more complex influence coefficients method. Qualitative and quantitative behavior was verified in a 1.5- by 2.0-in. helium shock tube. High speed Schlieren photography, piezoelectric pressure-time histories, and electronic-counter wave speed measurements were used to assess the extent of correlation with the theoretical flow models. Reduced data indicated the adequacy of the bounding theory approach to predict wave phenomena and quantitative response.

Grant, D. J.↗
NASA NTRS1972

The turbulent boundary layer on a porous plate - Experimental heat transfer with uniform blowing and suction, with moderately strong acceleration.

Experimental data are presented for heat transfer to the turbulent boundary layer subjected to transpiration and acceleration at constant values of the acceleration parameter K of approximately .00000145. This is a moderately strong acceleration, but not so strong as to result in laminarization of the boundary layer. The results for transpiration fractions F of -0.002, 0.0, and +0.0058 are presented in detail in tabular form, and in graphs of Stanton number versus enthalpy thickness Reynolds number. In addition, temperature profiles at several stations are presented. Stanton number results for F = -0.004, +0.002, and +0.004 are also presented, but in graphical form only. The data were obtained using air as both the free-stream and the transpired fluid, at relatively low velocities, and with temperature differences sufficiently low so that the influence of temperature-dependent fluid properties is minimal. All data were obtained with the surface maintained at a temperature invariant in the direction of flow.

Thielbahr, W. H.↗
NASA NTRS1972

Capillary gas chromatography with two new moderately high temperature phases.

Gas chromatography test results are presented for two new moderately high-temperature phases of Dexsil 400-GC with free hydroxyl end groups (uncapped) and with end groups covered by trimethyl silyl groups (capped). The two Dexsil 400-GC phases were tested for their ability to resolve N-TFA-DL-(+)-2-butyl esters and n-butyl esters, as well as fatty acid methyl esters and hydrocarbon standards. Generally the more polar uncapped phase was superior to the capped phase in all separation comparisons, except for the hydrocarbons.

Pollock, G. E.↗
NASA NTRS1973

Low-energy positrons from metallic moderators in a back scattering mode.

Evaluation of preliminary results of the emission of slow (about 1 eV) positrons from solid moderators. The results presented are for copper, gold, and aluminum and were obtained using the backscatter mode of operation. Of the three metals investigated, copper is found to emit positrons with the lowest energy, while aluminum emits those with the highest energy. Several small peaks are noted on the high-energy side of the spectra, especially in the case of gold and aluminum.-

Pendyala, S.↗
NASA NTRS1974

Fractionation of moderately volatile elements in ordinary chondrites

The CI chondrites are the most volatile-rich meteorites. Relative to the CI chondrites, the ordinary chondrites have lower abundances of refractory and volatile elements. Four types of fractionations are summarized in a table. Ordinary-chondrite/CI abundance ratios for moderately volatile elements in H- and L-group chondrites are presented in a graph. Possible explanations for the observed relations are considered, giving attention to several processes which could result in the separation of nebular solids and gases.

Wasson, J. T.↗
NASA NTRS1975

Simplified lifting-surface theory for flaps on wings of low and moderate aspect ratios

A modification of the simplified lifting-surface theory for wings with deflected flaps is presented and evaluated. The modification is simple and straightforward in application, and is shown to overcome the deficiency in the theory that results in an underestimation of flap lift effectiveness for wings that have low or moderate aspect ratios.

Wick, B. H.↗