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Results for “electric propulsion systems”

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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At least 55 records · Page 3
All sourcesNASA NTRSDOE OSTI
NASA NTRS2016

Design of an Electric Propulsion System for SCEPTOR

The rise of electric propulsion systems has pushed aircraft designers towards new and potentially transformative concepts. As part of this effort, NASA is leading the SCEPTOR program which aims at designing a fully electric distributed propulsion general aviation aircraft. This article highlights critical aspects of the design of SCEPTOR's propulsion system conceived at Joby Aviation in partnership with NASA, including motor electromagnetic design and optimization as well as cooling system integration. The motor is designed with a finite element based multi-objective optimization approach. This provides insight into important design tradeoffs such as mass versus efficiency, and enables a detailed quantitative comparison between different motor topologies. Secondly, a complete design and Computational Fluid Dynamics analysis of the air breathing cooling system is presented. The cooling system is fully integrated into the nacelle, contains little to no moving parts and only incurs a small drag penalty. Several concepts are considered and compared over a range of operating conditions. The study presents trade-offs between various parameters such as cooling efficiency, drag, mechanical simplicity and robustness.

SCEPTOR↗
NASA NTRS2015

NASA Electric Propulsion System Studies

An overview of NASA efforts in the area of hybrid electric and turboelectric propulsion in large transport. This overview includes a list of reasons why we are looking at transmitting some or all of the propulsive power for the aircraft electrically, a list of the different types of hybrid-turbo electric propulsion systems, and the results of 4 aircraft studies that examined different types of hybrid-turbo electric propulsion systems.

Jet Propulsion↗
NASA NTRS1982

A comparison of potential electric propulsion systems for orbit transfer

Electric propulsion concepts are compared on the basis of trip time for the low earth orbit (LEO) to geosynchronous earth orbit (GEO) mission. Resistojet, arcjet, magnetoplasmadynamic (MPD), pulsed inductive, and ion engine thruster concepts are included. The optimum (minimum trip time) value of specific impulse is found to be dependent upon the specific mission and system being considered. As expected, the devices which can deliver good efficiency at low specific impulses promise the fastest trip times. The solution for trip time and propellant mass for the constant power, continuous low acceleration orbit transfer problem (one way and round trip) is presented in nomograph form. The influences of mission Delta V, thruster efficiency, specific impulse, power, power and propulsion system mass, and payload mass are clearly illustrated.

Jones, R. M.↗
NASA NTRS2014

A Future with Hybrid Electric Propulsion Systems: A NASA Perspective

The presentation highlights a NASA perspective on Hybrid Electric Propulsion Systems for aeronautical applications. Discussed are results from NASA Advance Concepts Study for Aircraft Entering service in 2030 and beyond and the potential use of hybrid electric propulsion systems as a potential solution to the requirements for energy efficiency and environmental compatibility. Current progress and notional potential NASA research plans are presented.

Aircraft Design↗
NASA NTRS1971

Satellite auxiliary-propulsion selection techniques. Addendum: A survey of auxiliary electric propulsion systems

A review of electric thrusters for satellite auxiliary propulsion was conducted at JPL during the past year. Comparisons of the various thrusters for attitude propulsion and east-west and north-south stationkeeping were made based upon performance, mass, power, and demonstrated life. Reliability and cost are also discussed. The method of electrical acceleration of propellant served to divide the thruster systems into two groups: electrostatic and electromagnetic. Ion and colloid thrusters fall within the electrostatically accelerated group while MPD and pulsed plasma thrusters comprise the electromagnetically accelerated group. The survey was confined to research in the United States with accent on flight and flight prototype systems.

Holcomb, L. B.↗
NASA NTRS1983

Steady-state and dynamic evaluation of the electric propulsion system test bed vehicle on a road load simulator

The propulsion system of the Lewis Research Center's electric propulsion system test bed vehicle was tested on the road load simulator under the DOE Electric and Hybrid Vehicle Program. This propulsion system, consisting of a series-wound dc motor controlled by an infinitely variable SCR chopper and an 84-V battery pack, is typical of those used in electric vehicles made in 1976. Steady-state tests were conducted over a wide range of differential output torques and vehicle speeds. Efficiencies of all of the components were determined. Effects of temperature and voltage variations on the motor and the effect of voltage changes on the controller were examined. Energy consumption and energy efficiency for the system were determined over the B and C driving schedules of the SAE J227a test procedure.

Dustin, M. O.↗
NASA NTRS2015

Aircraft Electric Propulsion Systems Applied Research at NASA

Researchers at NASA are investigating the potential for electric propulsion systems to revolutionize the design of aircraft from the small-scale general aviation sector to commuter and transport-class vehicles. Electric propulsion provides new degrees of design freedom that may enable opportunities for tightly coupled design and optimization of the propulsion system with the aircraft structure and control systems. This could lead to extraordinary reductions in ownership and operating costs, greenhouse gas emissions, and noise annoyance levels. We are building testbeds, high-fidelity aircraft simulations, and the first highly distributed electric inhabited flight test vehicle to begin to explore these opportunities.

Clarke, Sean↗
NASA NTRS2015

Aircraft Electric Propulsion Systems Applied Research at NASA

Researchers at NASA are investigating the potential for electric propulsion systems to revolutionize the design of aircraft from the small-scale general aviation sector to commuter and transport-class vehicles. Electric propulsion provides new degrees of design freedom that may enable opportunities for tightly coupled design and optimization of the propulsion system with the aircraft structure and control systems. This could lead to extraordinary reductions in ownership and operating costs, greenhouse gas emissions, and noise annoyance levels. We are building testbeds, high-fidelity aircraft simulations, and the first highly distributed electric inhabited flight test vehicle to begin to explore these opportunities.

Clarke, Sean↗
NASA NTRS1980

Attitude control study for a large flexible spacecraft using a Solar Electric Propulsion System (SEPS)

The attitude control performance of the solar electric propulsion system (SEPS) was evaluated. A thrust vector control system for powered flight control was examined along with a gas jet reaction control system, and a reaction wheel system, both of which have been proposed for nonpowered flight control. Comprehensive computer simulations of each control system were made and evaluated using a 30 mode spacecraft model. Results obtained indicate that thrust vector control and reaction wheel systems offer acceptable smooth proportional control. The gas jet control system is shown to be risky for a flexible structure such as SEPS, and is therefore, not recommended as a primary control method.

Tolivar, A. F.↗