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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 487 records · Page 27

Twin-spool turbopumps for ''low'' net positive suction pressure operations

Modified single-shaft turbopump incorporates inducer and main pump, each separately driven at different speeds through coaxial-shaft arrangement. Inducer operates at low speed for low net positive suction pressure, main pump operates at high speed to generate high pressure. This arrangement requires no external control for the inducer.

Bair, E. K.↗

A preliminary control net of Mars

Mars surface areodetic control net from Mariner 6 and 7 TV pictures, determining initial coordinate points and far and near encounter frames

Berg, R. A.↗

Experimental findings from zero-tank net positive suction head operation of the J-2 hydrogen pump

The results of a series of liquid hydrogen turbopump tests to demonstrate the feasibility of zero-tank net positive suction head are presented. A J-2 engine hydrogen pump and S-IVB stage fuel feed system were used for this investigation. The pump was operated at flows and speeds equivalent to normal J-2 engine operating conditions and at hydrogen bulk temperatures between 39 and 45 R. These tests show zero-tank not positive suction head to be a realistic operating mode that should be considered for future applications.

Stinson, H. P.↗

Net vapor generation point in boiling flow of trichlorotrifluoroethane at high pressures

The conditions at which the void in subcooled boiling starts to undergo a rapid increase were studied experimentally. The experiments were performed in a 12.7 x 9.5 mm rectangular channel. Heating was from a 3.2 mm wide strip embedded in one wall. The pressure ranged from 9.45 to 20.7 bar, mass velocity from 600 to 7000 kg/sq m sec, and subcooling from 16 to 67 C. Photographs were used to determine when detached bubbles first appeared in the bulk flow. Measurements of bubble layer thickness along the wall were also made. Results showed that the point of net vapor generation is close to the occurrence of fully-developed boiling.

Dougall, R. S.↗

Mariner 9 control net of Mars, April 1973

A planet-wide geodetic control net of Mars that is based on the Mariner 9 television pictures has been in the process of being computed since January 1972. Results of the computations as of April 1973 are presented. Areocentric and areographic coordinates of 1340 control points have been computed using 613 frames and are presented tabularly. These coordinates will be revised as additional points and frames are added to the computation in the future.

Davis, M. E.↗

An economical net solar flux radiometer.

The theory and design of an economical solar flux radiometer readily adaptable to the conventional radiosonde system are presented in response to the need cited by the Atmospheric Radiation Working Group (1971) for the development of an inexpensive light-weight short-wave radiometer sonde. Prototype instrument tests and current modifications are discussed. It is shown that the basic instrument can be easily modified to measure separately the upward and downward directed flux components, in addition to the net flux.

Darkow, G. L.↗

Net-field polarization in a magnetically biased plasma.

Systematic treatment of the net-field polarization of a plane wave propagating in a magnetically biased cold plasma. Polarization transformations under quasi-longitudinal conditions are examined. The wide variety of polarization transformations available suggests the usefulness of slabs of magnetically biased plasma to synthesize microwave polarizers and depolarizers.

Rusch, W. V. T.↗

Mariner 9 control net Mars, June 1973

The latitude and longitude are reported for 1645 primary points in the control net of Mars. The points were derived from Mariner 9 photographs as of June 1973. The new Mariner 9 aerographic coordinates system used in performing the computations is discussed.

Davies, M. E.↗

Mariner 9 control net of Mars, August 1972

Results are presented for a planet-wide geodetic control net of Mars which is based on Mariner 9 pictures as of August 1972. Aerocentric and aerographic coordinate of 809 control points were computed from 407 television frames. Photogrammetric parameters and methodology used in the computations are discussed. The coordinates of the features are given and figures that show the locations of the control points on the surface of Mars are included.

Davies, M. E.↗

Net radiation method for transmission through partially transparent plates

It is shown that the net radiation method for enclosures with opaque surfaces described by Siegel and Howell (1972) can, in an appropriately adapted version, provide a computation procedure suitable for situations with semitransparent regions. This procedure involves simple equations at each interface and can be readily applied to complicated systems such as those consisting of absorbing and nonabsorbing layers, and layers with different reflectivities at each interface. The equations can also be readily incorporated in a computerized design procedure.

Siegel, R.↗

Geodetic control net

Computer program, originally developed for Mariner flyby missions, computes planetary control net from measurements of topographical features identified on television pictures. Program solves for areocentric coordinates of 115 surface points and orthogonal camera matrices of 57 far and near encounter pictures.

Davies, M. E.↗