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At least 901 records · Page 50

Large experimental wind turbines: Where we are now

Several large wind turbine projects have been initiated by NASA-Lewis as part of the ERDA wind energy program. The projects consist of progressively large wind turbine ranging from 100 kW with a rotor diameter of 125 feet to 1500 kW with rotor diameters of 200 to 300 feet. Also included is supporting research and technology for large wind turbines and for lowering the costs and increasing the reliability of the major wind turbine components. The results and status of the above projects are briefly discussed in this report. In addition, a brief summary and status of the plans for selecting the utility sites for the experimental wind turbines is also discussed.

Thomas, R. L.↗

Fabrication and assembly of the ERDA/NASA 100 kilowatt experimental wind turbine

As part of the Energy Research and Development Administration (ERDA) wind-energy program, NASA Lewis Research Center has designed and built an experimental 100-kW wind turbine. The two-bladed turbines drives a synchronous alternator that generates its maximum output of 100 kW of electrical power in a 29-km/hr (18-mph) wind. The design and assembly of the wind turbine were performed at Lewis from components that were procured from industry. The machine was installed atop the tower on September 3, 1975.

Puthoff, R. L.↗

DSN diplexer, noise burst testing

The testing of a new design high power S-band diplexer is reported. The megawatt Cassegrain diplexer (MCD) is to be used for DSN operations. The tests described were performed at 100 kW at the Venus Deep Space Station (DSS 13) transmitter test area. At 100 kW or less no degradation of receive performance was detected.

Kolbly, R. B.↗

Plasma core reactor simulations using RF uranium seeded argon discharges

Experimental results are described in which pure uranium hexafluoride was injected into an argon-confined, steady-state, RF-heated plasma to investigate characteristics of plasma core nuclear reactors. The 80 kW (13.56 MHz) and 1.2 MW (5.51 MHz) rf induction heater facilities were used to determine a test chamber flow scheme which offered best uranium confinement with minimum wall coating. The cylindrical fused-silica test chamber walls were 5.7-cm-ID by 10-cm-long. Test conditions included RF powers of 2-85 kW, chamber pressures of 1-12 atm, and uranium hexafluoride mass-flow rates of 0.005-0.13 g/s. Successful techniques were developed for fluid-mechanical confinement of RF-heated plasmas with pure uranium hexafluoride injection.

Roman, W. C.↗

Closed cycle MHD power generation experiments using a helium-cesium working fluid in the NASA Lewis Facility

The MHD channel in the NASA Lewis Research Center was redesigned and used in closed cycle power generation experiments with a helium-cesium working fluid. The cross sectional dimensions of the channel were reduced to 5 by 16.5 cm to allow operation over a variety of conditions. Experiments have been run at temperatures of 1900-2100 K and Mach numbers from 0.3 to 0.55 in argon and 0.2 in helium. Improvements in Hall voltage isolation and seed vaporization techniques have resulted in significant improvements in performance. Typical values obtained with helium are Faraday open circuit voltage 141 V (92% of uBh) at a magnetic field strength of 1.7 T, power outputs of 2.2 kw for tests with 28 electrodes and 2.1 kw for tests with 17 electrodes. Power densities of 0.6 MW/cu m and Hall fields of about 1100 V/m were obtained in the tests with 17 electrodes, representing a factor of 18 improvement over previously reported results. The V-I curves and current distribution data indicate that while near ideal equilibrium performance is obtained under some conditions, no nonequilibrium power has been generated to date.

Sovie, R. J.↗

Electronic transition CN laser

A 20 kW electric-discharge pumped CN laser oscillating on the A(2) Pi-X(2) Sigma molecular system is presented. Excitation is by a simple longitudinal discharge struck through HCN vapor. Twenty kW peak power is generated in a 150 nsec full-width half-maximum pulse. Two lasing bands were observed in the A-X system: the (0,1) and (0,2) bands near 1.42 and 2.0 microns respectively. Both P and Q branches are active in the two bands, with Q bands stronger. Peak laser energy is 3 mJ. Products of UV photolysis of HCN, electron impact excitation of HCN, and other possible excitation mechanisms and laser efficiency are discussed.

Quick, C. R., Jr.↗

Large experimental wind turbines - Where we are now

Several large wind turbine projects have been initiated by NASA-Lewis as part of the ERDA wind energy program. The projects consist of progressively large wind turbines ranging from 100 kW with a rotor diameter of 125 feet to 1500 kW with rotor diameters of 200 to 300 feet. Also included is supporting research and technology for large wind turbines and for lowering the costs and increasing the reliability of the major wind turbine components. The results and status of the above projects are briefly discussed in this report. In addition, a brief summary and status of the plans for selecting the utility sites for the experimental wind turbines is also discussed.

Thomas, R. L.↗

Investigations for the improvement of space shuttle main engine electron beam welding equipment

Progress made in the testing, evaluation, and correction of MSFC's 7.5 kW electron beam welder in support of space shuttle main engine component welding is summarized. The objective of this project was to locate and correct the deficiencies in the welder. Some 17 areas were deficient in the 7.5 kW ERI welding system and the associated corrective action was taken to improve its operational performance. An overall improvement of 20 times the original reliability was obtained at full rated capacity after the modifications were made.

Smock, R. A.↗

Orbital construction demonstration study. Volume 1: Executive summary

A conceptual design and program plan for an Orbital Construction Demonstration Article (OCDA), that can be used for technology growth and verification, and as the construction facility for a variety of large structures is presented. The OCDA design includes a large work platform, a rotating manipulator boom, a 250 kw solar array, and a core module of subsystems with a total mass of 37,093 kg, that can be assembled in three shuttle flights. An analysis of OCDA continued utility potential indicates that a shuttle tended platform with 250 kW of power can effectively be used to construct highly beneficial antenna systems and large demonstration articles that advance solar power satellite technologies. The construction of 100 m parabolic reflectors for use as a radiometer for measuring soil moisture and water salinity was found to be within the capabilities of OCDA concept. With 252 fixed beams for high population centers, and 16 scanning beams for rural areas, the antenna has the potential to significantly improve U.S. space based communications systems. The OCDA, that is slightly increased in size, was found adequate to build a large 2 MW solar array which, when coupled to a transmit antenna, demonstrate power transfer from space to ground.

Source record↗

Atmosphere, Magnetosphere and Plasmas in Space (AMPS). Spacelab payload definition study. Volume 7, book 3: Supporting Research and Technology (SR and T) report

The items identified as required to support the AMPS mission and requiring SR and T support and further work are: (1) a general purpose Experiment Pointing Mount; (2) a technique for measuring the attitude of the pallet-mounted or deployed experiments; (3) the development of a common optics cryogenically cooled interferometer spectrometer; (4) the development of a differential absorption lidar system for the measurement of ozone densitites in the earth's atmosphere; (5) the development of dc to dc power processors which are capable of converting energy stored in a capacitor system at 500 V to energy supplied to equipment operating at 40 kV and at 20 kW (eventually up to 100 kW); and (6) the development of a magnetic or possibly electrostatic deflection system capable of bending the beam of an electron accelerator. A data sheet is included for each item, briefly describing the background and need for each item, and the general objectives of the required development, and identifying the schedule requirements in support of the AMPS program.

Source record↗

Design definition of a mechanical capacitor

A design study and analyses of a 10 kW-hr, 15 kW mechanical capacitor system was studied. It was determined that magnetically supported wheels constructed of advanced composites have the potential for high energy density and high power density. Structural concepts are analyzed that yield the highest energy density of any structural design yet reported. Particular attention was paid to the problem of 'friction' caused by magnetic and I to the second power R losses in the suspension and motor-generator subsystems, and low design friction levels have been achieved. The potentially long shelf life of this system, and the absence of wearing parts, provide superior performance over conventional flywheels supported with mechanical bearings. Costs and economies of energy storage wheels were reviewed briefly.

Michaelis, T. D.↗

Baseline test data for the EVA electric vehicle

Two electric vehicles from Electric Vehicle Associates were evaluated for ERDA at the Transportation Research Center of Ohio. The vehicles, loaded to a gross vehicle weight of 3750 pounds, had a range of 56.3 miles at a steady speed of 25 mph and a 27.4 miles range during acceleration-deceleration tests to a top speed of 30 mph. Energy consumption varied from 0.48 kw-hr/mi. to 0.59 kw-hr/mi.

Harhay, W. C.↗

High power operation of a 30-cm mercury bombardment ion thruster

The nominal input power of a 30-cm mercury bombardment ion thruster is 2.5 kW. A representative 30-cm thruster has been operated at higher power levels by increasing either the ion beam voltage or current. Initial results indicate that higher voltage (high specific impulse) operation requires only minor modifications in thruster design. Higher current (low specific impulse) operation, on the other hand, requires improvements in the capabilities of the discharge chamber and ion optics assembly designs to meet lifetime and/or performance specifications. Experimental data is presented and considerations for high power operation (up to 10 kW) are discussed.

Poeschel, R. L.↗

Performance and heat transfer characteristics of the laser-heated rocket - A future space transportation system

The application of advanced liquid-bipropellant rocket engine analysis techniques has been utilized for prediction of the potential delivered performance and the design of thruster wall cooling schemes for laser-heated rocket thrusters. Delivered specific impulse values greater than 1000 lbf-sec/lbm are potentially achievable based on calculations for thrusters designed for 10-kW and 5000-kW laser beam power levels. A thruster wall-cooling technique utilizing a combination of regenerative cooling and a carbon-seeded hydrogen boundary layer is presented. The flowing carbon-seeded hydrogen boundary layer provides radiation absorption of the heat radiated from the high-temperature plasma. Also described is a forced convection thruster wall cooling design for an experimental test thruster.

Shoji, J. M.↗

Advanced spacecraft thermal control techniques

The problems of rejecting large amounts of heat from spacecraft were studied. Shuttle Space Laboratory heat rejection uses 1 kW for pumps and fans for every 5 kW (thermal) heat rejection. This is rather inefficient, and for future programs more efficient methods were examined. Two advanced systems were studied and compared to the present pumped-loop system. The advanced concepts are the air-cooled semipassive system, which features rejection of a large percentage of the load through the outer skin, and the heat pipe system, which incorporates heat pipes for every thermal control function.

Fritz, C. H.↗

DOE LeRC photovoltaic systems test facility

The facility was designed and built and is being operated as a national facility to serve the needs of the entire DOE National Photovoltaic Program. The object of the facility is to provide a place where photovoltaic systems may be assembled and electrically configured, without specific physical configuration, for operation and testing to evaluate their performance and characteristics. The facility as a breadboard system allows investigation of operational characteristics and checkout of components, subsystems and systems before they are mounted in field experiments or demonstrations. The facility as currently configured consist of 10 kW of solar arrays built from modules, two inverter test stations, a battery storage system, interface with local load and the utility grid, and instrumentation and control necessary to make a flexible operating facility. Expansion to 30 kW is planned for 1978. Test results and operating experience are summaried to show the variety of work that can be done with this facility.

Cull, R. C.↗

A pulser-sustainer carbon monoxide electric-discharge supersonic laser

Operation of a CW CO electric-discharge supersonic laser with a pulser-sustainer discharge is described. High-power operation as well as independent control over electron energy and density are demonstrated. Maximum input power achieved to date is 100 kW. The maximum output power is 6 kW or 10% of the sustainer positive-column power. Much improved performance appears possible.

Monson, D. J.↗

Next steps in space transportation and operations

Design of a 25-kW power or utilities module, capable of extending the effective duration of Spacelab missions, is discussed. The power module, planned for availability in 1984, could also support a Spacelab modified to be a free-flyer by providing attitude control and power. In addition, development of a 250-kW power module to support a Shuttle-tended space platform or a Shuttle-tended space construction base is projected. A free-flying teleoperator capable of deboosting Skylab, systems to construct large planar arrays in space, and a habitable module providing crew quarters for continuously manned operations are also described.

Disher, J. H.↗