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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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Boiling mechanism, two-phase flow mechanism, heat transfer to cryogenic fluids, and body force effect on boiling and two-phase flow
Corrosion resistance of Nb and Ta tubing alloys to boiling K
Discrete ordinates codes used to determine secondary gamma sources in reactor assemblies and shields
Design, construction, testing, and control devices for high-field electromagnets
Cryogenic properties of polymers - NASA/Case Conference, Cleveland, April 1967
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Research and development program for cryogenic and superconducting magnets
Cryogenically cooled superconducting electromagnets design, construction and properties for research in plasma and solid state physics, considering coil systems
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.
A review of the progress and milestones passed in the Brayton program is presented. The 2-to-15 kWe power system was successfully operated in a vacuum with a space-type radiator. Gas loop and electrical subsystem endurance tests have continued to demonstrate long-term operation with one rotating unit surpassing 10,000 hours of failure-free operation. Simplified gas-bearing designs for the rotating unit are being evaluated. Fabrication of an improved design of heat exchanger is nearing completion, and a study of more advanced heat exchanger technology is being conducted. A study was completed to investigate the applicability of Brayton technology applied to a lower power level (0.5 to 2.5 kWe) and showed potentially very attractive performance, simplicity, and low cost for a system in this power range.
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.
The overall aero and acoutic design features of eight 6-foot-diameter, single stage fans tested in an outdoor acoustic facility are described. A correlation of the acoustic results for subsonic tip-speed fans showed the total sound power was proportional to the mechanical power imparted to the fan and the specific work performed on the air to within + or - 2 dB. The correlation was relatively insensitive to fan design variables over a broad range of operating conditions. Maximum perceived noise levels were generally proportional to the sound power levels with both noise levels exhibiting a relatively unique increase with fan pressure ratio when normalized by the delivered thrust.
A review of the progress and milestones passed in the Brayton program during the past year is presented. The 2-to-15 kWe power system was successfully operated in a vacuum with a space-type radiator. Gas loop and electrical subsystem endurance tests have continued to demonstrate long-term operation with one rotating unit surpassing 10,000 hours of failure-free operation. Simplified gas-bearing designs for the rotating unit are being evaluated. Fabrication of an improved design of heat exchanger is nearing completion, and a study of more advanced heat exchanger technology is being conducted.
The overall aero and acoustic design features of eight 6-foot-diameter, single-stage fans tested in an outdoor acoustic facility are described. A correlation of the acoustic results for subsonic tip-speed fans showed the total sound power to be proportional to the mechanical power imparted to the fan and the specific work performed on the air to within plus or minus 2 dB. The correlation was relatively insensitive to fan design variables over a broad range of operating conditions. Maximum perceived noise levels were generally proportional to the sound power levels with both noise levels exhibiting a relatively unique increase with fan pressure ratio when normalized by the delivered thrust. The spectra of broadband noise attributed to the fan exhibited a bimodal characteristic for most of the fans. A predominant mode centered near the blade-passage tone and another at 8 to 16 times the tone frequency.
An outdoor facility constructed to evaluate solar collector performance for conditions that would be encountered by collectors if they were incorporated in a solar heating/cooling system is described. Preliminary performance data is presented.
Plans for the construction and operation of a solar heating and cooling system in conjunction with a office building being constructed at Langley Research Center, are discussed. Supporting research and technology includes: testing of solar collectors with a solar simulator, outdoor testing of collectors, property measurements of selective and nonselective coatings for solar collectors, and a solar model-systems test loop. The areas of a wind energy program that are being conducted include: design and operation of a 100-kW experimental wind generator, industry-designed and user-operated wind generators in the range of 50 to 3000 kW, and supporting research and technology for large wind energy systems. An overview of these activities is provided.
The purpose of the tests was to obtain overall performance and influencing factors as well as detailed measurements of the internal flow characteristics. The first experiment consisted of crossflow tests of a 15-inch diameter fan installed in a two-dimensional wing. Tests were run with and without exit louvers over a range of tunnel speeds, fan speeds, and wing angle of attack. The wing was used for a study of installation effects on lift fan performance. The model tested consisted of three 5.5-inch diameter tip-turbine driven model VTOL lift fans mounted chord-wise in the two-dimensional wing to simulate a pod-type array. Several inlet and exit cover door configurations and an adjacent fuselage panel were tested. For the third program, a pod was attached to the wing, and an investigation was conducted of the effect of design tip speed on the aerodynamic performance and noise of a 15-inch diameter lift fan-in-pod under static and crossflow conditions. Three single VTOL lift fan stages were designed for the same overall total pressure ratio but at three different rotor tip speeds.
The SUMMA superconducting magnetic mirror facility and the associated hot-ion plasma research were described. SUMMA is characterized by intense magnetic fields and a large-diameter working bore (41 cm diameter) with room-temperature access. The goal of the plasma research program is to produce steady-state plasmas of fusion reactor densities and temperatures (but not confinement times). The program includes electrode development to produce a hot, dense, large-volume, steady-state plasma and diagnostics development to document the plasma properties. SUMMA and its hot-ion plasma are ideally suited to develop advanced plasma diagnostics methods. Two such methods whose requirements are well matched to SUMMA are: (1) heavy ion beam probing to measure plasma space potential; and (2) submillimeter wavelength laser Thomson scattering to measure local ion temperature.