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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 235 records · Page 13

Foreword: Message From the MTS Journal Editor

Here, it is my pleasure to present this general issue to the MTS community. This general issue features manuscripts on a variety of topics of interest to the MTS community including articles, reviews, and commentaries: technology gaps for monitoring birds and marine mammals at offshore wind facilities; adaptive tracking of the Barents Sea polar front using an autonomous underwater vehicle; advanced simulation and environmental impact assessment of combustion in maritime energy systems; performance of moored real time ocean observations during Cyclones in the Bay of Bengal; recent advances in assessing environmental effects of marine renewable energy; and the new blue economy and future for marine renewable energy.

99 GENERAL AND MISCELLANEOUS↗

Data accompanying the publication "Sensitivity of grass fires burning in marginal conditions to atmospheric turbulence" in the Journal of Geophysical Research-Atmospheres

Data accompanying Jonko, Yedinak, Conley, and Linn (2021): "Sensitivity of grass fires burning in marginal conditions to atmospheric turbulence", JGR-Atmospheres. LA-UR-21-24832. The following files were generated from simulations performed with Los Alamos National Laboratory coupled atmosphere-fire behavior model FIRETEC v1.3: -area_burned.csv contains the area burned per second in m^2 for 45 CORE simulations, 20 INIT simulations and 20 BOUND simulations (85 columns), and 600 seconds of simulation (600 rows). -fire_perimeter.csv containing the fire perimeters in m for 45 CORE simulations, 20 INIT simulations and 20 BOUND simulations (85 columns), and 600 seconds of simulation (600 rows). -consumption_per_second.csv containing consumption in kg/s for 45 CORE simulations, 20 INIT simulations and 20 BOUND simulations (85 columns), and 600 seconds of simulation (600 rows). -rate_of_spread.csv containing the distance of the fire front from the ignition line in m for 45 CORE simulations, 20 INIT simulations and 20 BOUND simulations (85 columns), and 600 seconds of simulation (600 rows). -CORE1_u_10m_300_sec.hdf, INIT3_u_10m_300_sec.hdf, and BOUND3_u_10m_300_sec.hdf contain u wind speeds at 10 m height for 300 seconds (3D: time, x, y) of simulation for simulations CORE1, INIT3, and BOUND3, respectively. -CORE.final.fuel.density.hdf contains final fuel densities in the surface layer of the model (3D: ensemble member, x, y) for all 45 CORE simulations. -CORE{1-45}_3D_u_120_sec.hdf: 45 files containing vertically and horizontally resolved u winds for 120 seconds of simulation (4D: time, x, y, z) for the 45 CORE ensemble members. For additional information about this data, please contact the corresponding author at ajonko@lanl.gov.

54 ENVIRONMENTAL SCIENCES↗

A flexible cruciform journal bearing mount

Flexible mount achieves low roll, pitch and yaw stiffnesses while maintaining high radial stiffness by holding bearing pad in fixed relationship to deep web cruciform member and holding this member in fixed relationship to bearing support. This mount has particular application in small, high performance gas turbines.

Frost, A. E.↗

Externally pressurized gas-lubricated journal bearings with herringbone grooves - Load capacity and stability analysis.

A small eccentricity analysis was performed to predict load capacity and stability. Numerical results were obtained for a range of feeding parameter, pressure ratio, groove length and orifice recess volume for compressibility numbers from 0 to 50. These results were obtained from a digital computer program. Results showed that the addition of herringbone grooving to an externally pressurized bearing increases stability, but reduces load capacity at low compressibility numbers. A fully-grooved bearing is more stable than a partially-grooved bearing. Orifice recesses reduce stability, especially at high compressibility numbers.

Fleming, D. P.↗

Journal bearings

A plurality of bearing sectors are mounted in a housing. Each sector functions as a lobed area in the bearing to obtain the required lubricant film geometry.

Schuller, F. T.↗

Journal Bearings

A plurality of bearing sectors are mounted in a housing. Each sector functions as a lobed area in the bearing to obtain the required lubricant film geometry.

Schuller, F. T.↗

Experimental dynamic stiffness and damping of externally pressurized gas-lubricated journal bearings

A rigid vertical shaft was operated with known amounts of unbalance at speeds to 30,000 rpm and gas supply pressure ratios to 4.8. From measured amplitude and phase angle data, dynamic stiffness and damping coefficients of the bearings were determined. The measured stiffness was proportional to the supply pressure, while damping was little affected by supply pressure. Damping dropped rapidly as the fractional frequency whirl threshold was approached. A small-eccentricity analysis overpredicted the stiffness by 20 to 70 percent. Predicted damping was lower than measured at low speeds but higher at high speeds.

Fleming, D. P.↗

Dynamic stiffness and damping of externally pressurized gas lubricated journal bearings

A rigid vertical shaft was operated with known amounts of unbalance at speeds up to 30,000 rpm and gas supply pressure ratios to 4.8. From measured amplitude and phase angle data, dynamic stiffness and damping coefficients of the bearings were determined. The measured stiffness was proportional to the supply pressure, while damping was little affected by supply pressure. Damping dropped rapidly as the fractional frequency whirl threshold was approached. A small eccentricity analysis overpredicted the stiffness by 4 to 55 percent. Predicted damping was close to measured at low speeds but higher at high speeds

Fleming, D. P.↗

A pressurized gas squeeze film journal damper

A lumped parameter model is developed to determine the stiffness and damping characteristics of inherently compensated gas film bearings. The model relies on the average static pressure over a one dimensional strip bearing. Results of the model are compared with known computer solutions for the distributed strip and a two dimensional square bearing. The results for the stiffness agree well with the computer solutions although the model proved to be inadequate for predicting the film damping.

Stiffler, A. K.↗

A bibliography of space books and articles from non-aerospace journals, 1957-1977

This bibliography cites over 3,600 articles and books from the nonspecialized secondary literature relating to NASA and to aerospace-related themes. Entries are arranged alphabetically by author in the following categories: (1) space activity; (2) spaceflight: earliest times to the creation of NASA; (3) organization, administration, and management of NASA; (4) aeronautics; (5) boosters and rockets; (6) technology of spaceflight; (7) manned spaceflight; (8) space science; (9) applications; (10) space law; (11) international implications; (12) foreign space programs; (13) domestic public policy and opinion; and (14) economics: impact of NASA, analyses of aerospace industry, and patent policy.

Looney, J. J.↗