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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 667 records · Page 37

Recent radial turbine research at the NASA Lewis Research Center

The high efficiencies of small radial turbines led to their application in space power systems and numerous APU and shaft power engines. Experimental and analytical work associated with these systems included examination of blade-shroud clearance, blade loading, and exit diffuser design. Results indicate high efficiency over a wide range of specific speed and also insensitivity to clearance and blade loading in the radial part of the rotor. The exit diffuser investigation indicated that a conventional conical outer wall may not provide the velocity variation consistent with minimum overall diffuser loss.

Rohlik, H. E.↗

Recent radial turbine research at the NASA Lewis Research Center.

The major results obtained in several recent experimental programs on small radial inflow turbines for space applications are presented and discussed. Specifically, experimental and analytical work associated with these systems that has included examination of blade-shroud clearance, blade loading, and exit diffuser design, is considered. Results indicate high efficiency over a wide range of specific speed, and also insensitivity to clearance and blade loading in the radial part of the rotor. The exit diffuser investigation indicated that a conventional conical outer wall may not provide the velocity variation consistent with minimum overall diffuser loss.

Rohlik, H. E.↗

Fatigue and fracture basic research at the Langley Research Center.

This paper gives some examples of projects underway. The projects are grouped according to the primary parameter being studied: loads, configuration, environment, or material. Significant topics include the effect of truncated loads, the effect of proof-tests, interference fasteners, accelerated and real-time tests for supersonic aircraft materials, crack-growth rates in built-up structures, and a model method by which material can be selected for a particular set of operating conditions.

Davidson, J. R.↗

Research on techniques for laser ranging to optical corner reflectors on the moon. Research on laser techniques and single photo-electron detection and timing

Experimental studies using a pulsed LED, Cerenkov source, and a 100 ps laser were made of various photomultipliers and discriminator combinations. In addition, a new type of neodymium-YAG frequency doubled laser was used as the basis for the development of a stable, short pulse, high repetition rate laser system. This laser was then used in conjunction with atomic clocks to study the effect of gravitational potential on elapsed time. Avenues to promote the development of international cooperation in the area of lunar laser ranging were also explored.

Alley, C. O.↗

General aviation energy-conservation research programs at NASA-Lewis Research Center

The major thrust of NASA's nonturbine general aviation engine programs is directed toward (1) reduced specific fuel consumption, (2) improved fuel tolerance; and (3) emission reduction. Current and planned future programs in such areas as lean operation, improved fuel management, advanced cooling techniques and advanced engine concepts, are described. These are expected to lay the technology base, by the mid to latter 1980's, for engines whose total fuel costs are as much as 30% lower than today's conventional engines.

Willis, E. A.↗

General aviation internal-combustion engine research programs at NASA-Lewis Research Center

An update is presented of non-turbine general aviation engine programs. The program encompasses conventional, lightweight diesel and rotary engines. It's three major thrusts are: (1) reduced SFC's; (2) improved fuels tolerance; and (3) reduced emissions. Current and planned future programs in such areas as lean operation, improved fuel management, advanced cooling techniques and advanced engine concepts, are described. These are expected to lay the technology base, by the mid to latter 1980's, for engines whose life cycle fuel costs are 30 to 50% lower than today's conventional engines.

Willis, E. A.↗