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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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Nonmagnetic metal rings imbedded in a homopolar generator rotor normal to its axis keep the induction flux entering the rotor in a radial path. Use of the rings permits optimum rotor design for any given set of operating requirements and simplifies the task of predicting the operation characteristics of the generator.
The need for a stable source of low-frequency power is often encountered in studies of recording-instruments performance. Indeed, in laboratory work involving the design and analysis of servo mechanisms in general, a low-frequency signal source is of paramount importance. The generator described herein was designed specifically to serve as a signal source for determination of the frequency characteristics of the various recording instruments in use at this Laboratory. Flexibility and convenience of operation in the dynamic testing of recording instruments characterize the generator which has been evolved.
Epitaxial gallium arsenide diode junction formed in a crossed waveguide structure operates as a variable reactance harmonic generator. This varactor diode can generate power efficiently in the low-millimeter wavelength.
Instrument tests various electric power generating devices by connecting the devices to the input of the load and comparing their outputs with a reference voltage. The load automatically adjusts until voltage output of the power generating device matches the reference.
Gas generation system, used for recovery of submerged objects, generates hydrogen gas by the reaction of sodium with sea water. The assembly consists of flooded flotation tanks cabled together, equipped with relief valves to equalize pressure as the array ascends and hydrostatic pressure diminishes, and carrying remotely activated welding units.
Low-inductance, high-capacitance Marx pulse generator provides for minimization of internal inductance and suppression of external electromagnetic radiation. The spark gaps of the generator are enclosed in a pressurized nitrogen atmosphere which allows the charging voltage to be varied by changing the nitrogen pressure.
A parametric analysis of a radioisotope-thermoelectric power generator is presented. A cylindrical heat-source geometry was assumed with either lead telluride or silicon-germanium thermoelectric elements located around the lateral surface of the fuel block. Generator performance, rather than overall power-system performance, was analyzed; that is, such mission dependent considerations as nuclear shielding, reentry protection, and power conditioning were not included.
Impact of solar wind on lunar unipolar generator, investigating generation of two current systems
During the past few years, considerable effort has been exerted by both industry and government to improve the performance of space power systems. One of the significant advances has been the development of practical Maximum Power-Point Tracking (MPPT) systems. This paper presents the background and evolution of a second-generation (high-speed) MPPT system capable of operation with solar arrays with rapidly fluctuating parameters due to mission operation (e.g., spin-stabilized spacecraft). An experimental model of the high-speed MPPT system has been constructed and tested. Results from these tests are presented herein. The second-generation MPPT system provides a means of efficient power conditioning that can result in significant increases over conventional systems in space-power system capability. Of additional importance is the applicability of the basic technology to all types of spacecraft, and the wide variety of power-system configurations with which the high-speed MPPT system concept may be used.
Analysis and solution are presented for transient thermal stresses in a free heat-generating flat plate and a free, hollow-generating cylinder as a result of sudden environmental changes. The technique used and graphical results obtained are of interest to the heat transfer industry.
Discussion of magnetohydrodynamic induction generator examines the machine in detail and materials problems influencing its design. The higher upper-temperature limit of the MHD system promises to be more efficient than present turbine systems for generating electricity.
Circuitry for digitally generating an exponentially decaying wave function permits discrete values to be sampled from the exponential waveform for comparison with a binary number of specified accuracy. This exponential-decay generator employs a simple binary counter to count in the sequence of exponential decay.
Electroquasistatic generator depends on electroquasistatic interactions to provide synchronous operation. The generator employs a moving insulating belt, with an ac electric potential source to establish positively and negatively charged regions on the belt. The field effect of the charges on the belt creates an ac output voltage.
Generator has an improved circuit for generating a controllable, high voltage spark having a constant known energy output. It can be used for testing the flash and ignition characteristics of nonmetallic materials in a controlled gas environment.
Generation of electric power by liquid sodium-jet MHD generator
Heat generation calculations and heat transfer measurements in circulating currents of linear crossed field generators and accelerators
Design and performance equations for panel type solar thermoelectric generator, based on single thermocouple as generator unit
High efficiency thermoelectric generator utilizes a high-temperature thermoelectric material in thermal series with a low-temperature material. A thermally cascaded generator increases system efficiency.