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Results for “electric supercharging”

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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Electric field measurements during supercharging events on the MAIMIK rocket experiment

Data are presented on the evolution of electric field structures near the MAIMIK mother-daughter tethered rocket during active electron emissions from the rocket, which consisted of two separately instrumented payload sections which were detached in-flight. The results of the E field data analysis show that the temporal behavior of the fields was consistent with ion responses to the rapid charging of the active payload. A qualitative model of the interaction between the active payload and the ambient plasma background is developed to explain the electric field data, including the apparent causal relationship between the radial and tangential impulse components.

Denig, W. F.↗

Grain-Scale Supercharging and Breakdown on Airless Regoliths

Interactions of the solar wind and emitted photoelectrons with airless bodies have been studied extensively. However, the details of how charged particles interact with the regolith at the scale of a single grain have remained largely uncharacterized. Recent efforts have focused upon determining total surface charge under photoemission and solar wind bombardment and the associated electric field and potential. In this work, theory and simulations are used to show that grain-grain charge differences can exceed classical sheath predictions by several orders of magnitude, sometimes reaching dielectric breakdown levels. Temperature-dependent electrical conductivity works against supercharging by allowing current to leak through individual grains; the balance between internal conduction and surface charging controls the maximum possible grain-to-grain electric field. Understanding the finer details of regolith grain charging, conductive equilibrium, and dielectric breakdown will improve future numerical studies of space weathering and dust levitation on airless bodies.

airless↗

Intense localized photoelectric charging in the lunar sunset terminator region. I - Development of potentials and fields. II - Supercharging at the progression of sunset

Numerical computations show that locally sunlit areas in the dark lunar sunset terminator region can acquire large electric potentials and fields due to the retention of photoelectrons emitted from sunlit areas by surrounding dark areas of the highly resistive lunar surface. It is shown that the potential can increase or decrease depending on the rates of photoelectron emission and areal contraction. It is concluded that in the lunar situation, the likely result is an increase in the potential, or a 'supercharging' of the sunlit area.

Criswell, D. R.↗

The Application of High-temperature Strain Gauges to the Measurements of Vibratory Stresses in Gas-turbine Buckets

The feasibility of measuring the vibration in the buckets of a gas turbine under service conditions of speed and temperature was determined by use of a high temperature wire strain gauge cemented to a modified supercharger turbine bucket. A high-temperature wire strain gauge and the auxiliary mechanical and electrical equipment developed for the investigation are described.

Kemp, R H↗

Performance of a Fuel-Cell-Powered, Small Electric Airplane Assessed

Rapidly emerging fuel-cell-power technologies may be used to launch a new revolution of electric propulsion systems for light aircraft. Future small electric airplanes using fuel cell technologies hold the promise of high reliability, low maintenance, low noise, and - with the exception of water vapor - zero emissions. An analytical feasibility and performance assessment was conducted by NASA Glenn Research Center's Airbreathing Systems Analysis Office of a fuel-cell-powered, propeller-driven, small electric airplane based on a model of the MCR-01 two-place kitplane (Dyn'Aero, Darois, France). This assessment was conducted in parallel with an ongoing effort by the Advanced Technology Products Corporation and the Foundation for Advancing Science and Technology Education. Their project - partially funded by a NASA grant - is to design, build, and fly the first manned, continuously propelled, nongliding electric airplane. In our study, an analytical performance model of a proton exchange membrane (PEM) fuel cell propulsion system was developed and applied to a notional, two-place light airplane modeled after the MCR-01 kitplane. The PEM fuel cell stack was fed pure hydrogen fuel and humidified ambient air via a small automotive centrifugal supercharger. The fuel cell performance models were based on chemical reaction analyses calibrated with published data from the fledgling U.S. automotive fuel cell industry. Electric propeller motors, rated at two shaft power levels in separate assessments, were used to directly drive a two-bladed, variable-pitch propeller. Fuel sources considered were compressed hydrogen gas and cryogenic liquid hydrogen. Both of these fuel sources provided pure, contaminant-free hydrogen for the PEM cells.

Berton, Jeffrey J.↗

Photoelectric charging of partially sunlit dielectric surfaces in space

Sunlight-shadow effects may substantially alter the charging situation for a dielectric surface. The sunlight-shadow boundary tends to be the site of intense multipole electric fields. Charges on a sunlit dielectric surface have a finite effective mobility. The charge distribution tends to resemble that on a conducting surface. A boundary between a conducting and a dielectric surface may not represent a conductivity discontinuity when this boundary is sunlit; charges may migrate at a nontrivial rate across the boundary. A contracting or expanding sunlit area may experience a supercharging.

De, B. R.↗