Search NASA⌕ Search

SEARCH · Search NASA

Results for “Electrical techniques”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 73 records · Page 4
All sourcesNASA NTRSDOE OSTI
NASA NTRS1974

Analysis and calculation of lightning-induced voltages in aircraft electrical circuits

Techniques to calculate the transfer functions relating lightning-induced voltages in aircraft electrical circuits to aircraft physical characteristics and lightning current parameters are discussed. The analytical work was carried out concurrently with an experimental program of measurements of lightning-induced voltages in the electrical circuits of an F89-J aircraft. A computer program, ETCAL, developed earlier to calculate resistive and inductive transfer functions is refined to account for skin effect, providing results more valid over a wider range of lightning waveshapes than formerly possible. A computer program, WING, is derived to calculate the resistive and inductive transfer functions between a basic aircraft wing and a circuit conductor inside it. Good agreement is obtained between transfer inductances calculated by WING and those reduced from measured data by ETCAL. This computer program shows promise of expansion to permit eventual calculation of potential lightning-induced voltages in electrical circuits of complete aircraft in the design stage.

Plumer, J. A.↗
NASA NTRS2001

Microscale Particulate Classifiers (MiPAC) Being Developed

The NASA Glenn Research Center is developing microscale sensors to characterize atmospheric-borne particulates. The devices are fabricated using MEMS (microelectromechanical systems) technologies. These technologies are derived from those originally developed in support of the semiconductor processing industry. The resulting microsensors can characterize a wide range of particles and are, therefore, suitable to a broad range of applications. This project is supported under a collaborative program called the Glennan Microsystems Initiative. The initiative comprises members of NASA Glenn Research Center, various university affiliates from the State of Ohio, and a number of participating industrial partners. Funding is jointly provided by NASA, the State of Ohio, and industrial members. The work described here is a collaborative arrangement between researchers at Glenn, the University of Minnesota, The National Institute of Standards and Technology (NIST), and the Cleveland State University. Actual device fabrication is conducted at Glenn and at the laboratories of Case Western Reserve University. Case Western is also located in Cleveland, Ohio, and is a participating member of the initiative. The principal investigator for this project is Paul S. Greenberg of Glenn. Two basic types of devices are being developed, and target different ranges of particle sizes. The first class of devices, which is used to measure nanoparticles (i.e., particles in the range of 0.002 to 1 mm), is based on the technique of Electrical Mobility Classification. This technique also affords the valuable ability of measuring the electrical charge state of the particles. Such information is important in the understanding of agglomeration mechanisms and is useful in the development of methods for particle repulsion. The second type of device being developed, which utilizes optical scattering, is suitable for particles larger than 1 mm. This technique also provides information on particle shape and composition. Applications for these sensors include fundamental planetary climatology, monitoring and filtration in spacecraft, human habitation modules and related systems, characterization of particulate emissions from propulsion and power systems, and as early warning sensors for both space-based and ter-restrial fire detection. These devices are also suitable for characterizing biological compounds such as allergens, infectious agents, and biotoxic agents.

Greenberg, Paul S.↗
DOE OSTI2025

Thermodynamics, local structure, and transport of protons in triple-conducing oxide, BaCo 0.4 Fe 0.4 Zr 0.1 Y 0.1 O 3-δ (BCFZY4411)

Triple-conducting oxides (TCOs) are an emerging class of mixed ionic and electronically conducting materials that show great promise for oxygen reduction/oxygen evolution (ORR/OER) electrocatalysis—primarily in high-temperature ceramic electrochemical cells— but also in aqueous alkaline environments. Their high activity is attributed, at least in part, to their ability to incorporate and transport three mobile charge carriers: protons, oxygen vacancies, and electron-holes Despite their promise, fundamental studies of TCOs are challenging, as transport dynamics from three charge carriers cannot be fully disentangled via traditional electrical measurement techniques. Characterizing proton dynamics in TCOs is particularly difficult as protons are generally the minority carrier, and their conduction response is typically obscured by the oxygen vacancies and electron holes. Here, we demonstrate successful isolation of the proton behavior in an archetypal TCO, BaCo 0.4 Fe 0.4 Zr 0.1 Y 0.1 O 3-δ (BCFZY4411), using a combination of non-electrical techniques. We determine proton uptake and oxygen non-stoichiometry (δ) using thermogravimetric analysis (TGA). X-ray absorption near edge structure (XANES) and neutron diffraction (ND) are used to validate the oxidation state of Co and the δ values obtained through TGA. We apply 1H solid-state magic-angle-spinning (MAS) nuclear magnetic resonance (NMR) to provide insights into local structure, dynamics, and proton kinetics. Finally, the proton transport properties are further quantified using tracer isotope exchange with time-of-flight secondary ion mass spectrometry (ToF-SIMS). Despite the very low proton concentrations in BCFZY4411 (<0.2% under most conditions), our analysis suggests that the oxygen Manuscript File Click here to view linked References 2 reduction and evolution reactions are nevertheless limited by the oxygen ion kinetics (e.g., oxygen surface exchange) rather than the proton kinetics at the reduced operating temperatures (<500 °C) that are targeted for electrochemical cell applications. These findings provide a comprehensive understanding of proton behavior in BCFZY4411 and pave the way for advancing the fundamental study of TCOs.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
NASA NTRS1975

Field-aligned electric currents and their measurement by the incoherent backscatter technique

Field aligned electric currents flow in the magnetosphere in many situations of fundamental geophysical interest. It is shown here that the incoherent backscatter technique can be used to measure these currents when the plasma line can be observed. The technique provides a ground based means of measuring these currents which complements the rocket and satellite ones.

Bauer, P.↗
NASA NTRSDate not supplied

Update on SUSAN Concept Vehicle Power and Propulsion System

This paper provides an update on the power and propulsion (P&P) system design for the SUbsonic Single Aft eNgine (SUSAN) Electrofan. The SUSAN vehicle concept is a transformative concept hybrid electric aircraft with a single tail-mounted turbofan engine that provides thrust and power to 16 electric propulsors located on the wings. This configuration makes uses of large-scale power extraction along with a high-power electrical system transmitting 20 MW of power from the engine to the wing propulsors. This paper goes into detail on P&P advances relating turbine engine design, electrical system capabilities, advanced turbine control techniques, and electrical system cooling techniques. It should be noted that the SUSAN concept continues to be developed and this paper simply offers an update on the design.

aircraft concept↗
NASA NTRSDate not supplied

Update on SUSAN Concept Vehicle Power and Propulsion System

This paper provides an update on the power and propulsion (P&P) system design for the SUbsonic Single Aft eNgine (SUSAN) Electrofan. The SUSAN vehicle concept is a transformative concept hybrid electric aircraft with a single tail-mounted turbofan engine that provides thrust and power to 16 electric propulsors located on the wings. This configuration makes uses of large-scale power extraction along with a high-power electrical system transmitting 20 MW of power from the engine to the wing propulsors. This paper goes into detail on P&P advances relating turbine engine design, electrical system capabilities, advanced turbine control techniques, and electrical system cooling techniques. It should be noted that the SUSAN concept continues to be developed and this paper simply offers an update on the design.

aircraft concept↗
NASA NTRSDate not supplied

Update on SUSAN Concept Vehicle Power and Propulsion System

This paper provides an update on the power and propulsion (P&P) system design for the SUbsonic Single Aft eNgine (SUSAN) Electrofan. The SUSAN vehicle concept is a transformative concept hybrid electric aircraft with a single tail-mounted turbofan engine that provides thrust and power to 16 electric propulsors located on the wings. This configuration makes uses of large-scale power extraction along with a high-power electrical system transmitting 20 MW of power from the engine to the wing propulsors. This paper goes into detail on P&P advances relating turbine engine design, electrical system capabilities, advanced turbine control techniques, and electrical system cooling techniques. It should be noted that the SUSAN concept continues to be developed and this paper simply offers an update on the design.

aircraft concept↗
NASA NTRS2002

Transient Torque Technique for Viscosity and Electrical Conductivity Determination of Semiconducting Liquids

A novel apparatus based on transient torque technique is constructed in MSFC/NASA. The apparatus uses a 125um diameter quartz fiber as torsion wire. A high sensitive angular detector is implemented to measure the deflection angle of the crucible containing the liquid. A rotating magnetic field (RMF) is used to induce a rotating flow of a conducting or semiconducting melts. By measuring the magnitude and transient behavior of the induced deflection angle, the electrical conductivity and viscosity of the melt can be measured simultaneously. High purity elements namely Hg, Ga, Zn and Te are tested at room temperature and high temperature up to 900 C.

Li, C.↗
NASA NTRS1974

Electrical hand tools and techniques: A compilation

Space technology utilization for developing tools, adapters, and fixtures and procedures for assembling, installing, and servicing electrical components and equipment are discussed. Some of the items considered are: (1) pivotal screwdriver, (2) termination locator tool for shielded cables, (3) solder application tools, (4) insulation and shield removing tool, and (5) torque wrench adapter for cable connector engaging ring. Diagrams of the various tools and devices are provided.

Source record↗
NASA NTRS1977

Active control of electric potential of spacecraft

Techniques are discussed for controlling the potential of a spacecraft by means of devices which release appropriate charged particles from the spacecraft to the environment. Attention is given to electron emitters, ion emitters, a basic electron emitter arrangement, techniques for sensing electric field or potential, and flight experiments on active potential control. It is recommended to avoid differential charging on spacecraft surfaces because it can severely affect the efficacy of emitters. Discharging the frame of a spacecraft with dielectric surfaces involves the risk of stressing the dielectric material excessively. The spacecraft should, therefore, be provided with grounded conductive surfaces. It is pointed out that particles released by control systems can return to the spacecraft.

Goldstein, R.↗
NASA NTRS1989

Development of parallel algorithms for electrical power management in space applications

The application of parallel techniques for electrical power system analysis is discussed. The Newton-Raphson method of load flow analysis was used along with the decomposition-coordination technique to perform load flow analysis. The decomposition-coordination technique enables tasks to be performed in parallel by partitioning the electrical power system into independent local problems. Each independent local problem represents a portion of the total electrical power system on which a loan flow analysis can be performed. The load flow analysis is performed on these partitioned elements by using the Newton-Raphson load flow method. These independent local problems will produce results for voltage and power which can then be passed to the coordinator portion of the solution procedure. The coordinator problem uses the results of the local problems to determine if any correction is needed on the local problems. The coordinator problem is also solved by an iterative method much like the local problem. The iterative method for the coordination problem will also be the Newton-Raphson method. Therefore, each iteration at the coordination level will result in new values for the local problems. The local problems will have to be solved again along with the coordinator problem until some convergence conditions are met.

Berry, Frederick C.↗
NASA NTRS1977

Computer aided nonlinear electrical networks analysis

Techniques used in simulating an electrical circuit with nonlinear elements for use in computer-aided circuit analysis programs are described. Elements of the circuit include capacitors, resistors, inductors, transistors, diodes, and voltage and current sources (constant or time varying). Simulation features are discussed for dc, ac, and/or transient circuit analysis. Calculations are based on the model approach of formulating the circuit equations. A particular solution of transient analysis for nonlinear storage elements is described.

Slapnicar, P.↗
NASA NTRS2000

Applications of Low Density Flow Techniques and Catalytic Recombination at the Johnson Space Center

The talk presents a brief background on defInitions of catalysis and effects associated with chemically nonequilibrium and low-density flows of aerospace interest. Applications of catalytic recombination on surfaces in dissociated flow are given, including aero heating on reentry spacecraft thermal protection surfaces and reflection of plume flow on pressure distributions associated with the space station. Examples include aero heating predictions for the X-38 test vehicle, the inlet of a proposed gas-sampling probe used in high enthalpy test facilities, and a parabolic body at angle of attack. The effect of accommodation coefficients on thruster induced pressure distributions is also included. Examples of tools used include simple aero heating formulas based on boundary layer solutions, an engineering approximation that uses axisymmetric viscous shock layer flow to simulate full three dimensional flow, full computational fluid dynamics, and direct simulation Monte-Carlo calculations. Methods of determining catalytic recombination rates in arc jet flow are discus ed. An area of catalysis not fully understood is the formation of single-wall carbon nanotubes (SWNT) with gas phase or nano-size metal particles. The Johnson Space Center is making SWNTs using both a laser ablation technique and an electric arc vaporization technique.

Scott, Carl D.↗