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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 145 records · Page 8

Flow velocities and streamlines

Computer program calculates subsonic or transonic flow on hubshroud, midchannel, stream surface of single-blade row of turbomachine. Program uses finite-different and quasi-orthogonal (velocity-gradient) methods. Program is reported in two volumes: Part I is User's Manual, Part II is Programmer's Manual.

Katsanis, T.↗

Structures and mechanisms - Streamlining for fuel economy

The design of prospective NASA space station components which inherently possess the means for structural growth without compromising initial system characteristics is considered. In structural design terms, space station growth can be achieved by increasing design safety factors, introducing dynamic isolators to prevent loads from reaching the initial components, or preplanning the refurbishment of the original structure with stronger elements. Design tradeoffs will be based on the definition of on-orbit loads, including docking and maneuvering, whose derived load spectra will allow the estimation of fatigue life. Improvements must be made in structural materials selection in order to reduce contamination, slow degradation, and extend the life of coatings. To minimize on-orbit maintenance, long service life lubrication systems with advanced sealing devices must be developed.

Card, M. F.↗

Tests on a CAST 7 two-dimensional airfoil in a streamlining test section

A unique opportunity has arisen to test one and the same airfoil model of CAST-7 section in two wind tunnels having adaptive walled test sections. The tunnels are very similar in terms of size and the available range of test conditions, but differ principally in their wall setting algorithms. Detailed data from the tests of the model in the Southampton tunnel, are included with comparisons between various sources of data indicating that both adaptive walled test sections provide low interference test conditions.

Goodyear, M. J.↗

Streamlining shuttle ground operations

To meet NASA Space Transportation System goals the Shuttle Processing Contractors have to reduce Space Transportation System ground processing time and ground processing costs. These objectives must be met without compromising safety of flight or safety during assembly, test, and service operations. Ground processing requirements are analyzed to determine critical serial flow paths and costly labor-intensive tasks. Processing improvements are realized by improvements in processing methodology, by application of computer-aided technology, and by modernization of KSC facilities. Ongoing improvement efforts are outlined and progress-to-date is described.

Heimbold, R. L.↗

Streamlining algorithms for complete adaptation

For purposes of the adaptive-wall algorithms to be described, the modern era is considered to have begun with the simultaneous, independent recognition of the concept of matching an experimental inner flow across an interface to a computed outer flow by Chevallier, Ferri, Goodyer, Lissaman, Rubbert, and Sears. Fundamental investigations of the adaptive-wall matching concept by means of numerical simulations and theoretical considerations are described. An overview of the development and operation of 2D adaptive-wall facilities from about 1970 until the present is given, followed by similar material for 3D adaptive-wall facilities from approximately 1978 until the present. A general formulation of adaptation strategy is presented, with a theoretical basis for adaptation followed by 2D flexible, impermeable-wall applications; 2D ventilated-wall applications; 3D flexible, impermeable-wall applications; and 3D ventilated-wall applications. Representative experimental and 3D results are given, with 2D, followed by a discussion of limitations and open questions.

Erickson, J. C., Jr.↗

STME - Streamlining the engine of change

The key to the success of the NASA Space Transportation Main Engine (STME) is its enhanced reliability and reduced costs, rather than enhanced performance and reduced weight. Reliability and cost improvements derive from the design of an engine with fewer components, wider operating margins, conventional materials, and innovative manufacturing techniques; this is exemplified by the STME's combustion chamber, in which the structural jacket and all minifolds are cast as a single piece. 'Platelet' technology is under active consideration as a basis for the nozzle design. The use of hydrostatic bearings in both the turbine and pump ends of the STME turbopump will eliminate bearing-life limitations.

Smelser, Jerry W.↗

Streamline curvature in supersonic shear layers

Results of an experimental investigation in which a curved shear layer was generated between supersonic flow from a rectangular converging/diverging nozzle and the freestream in a series of open channels with varying radii of curvature are reported. The shear layers exhibit unsteady large-scale activity at supersonic pressure ratios, indicating increased mixing efficiency. This effect contrasts with supersonic flow in a straight channel, for which no large-scale vortical structure development occurs. Curvature must exceed a minimum level before it begins to affect the dynamics of the supersonic shear layer appreciably. The curved channel flows are compared with reference flows consisting of a free jet, a straight channel, and wall jets without sidewalls on a flat and a curved plate.

Kibens, V.↗