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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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At least 163 records · Page 9

Flight Performance Estimates for the NASA X-57 Distributed Electric Propulsion Flight Demonstrator

The X-57 flight demonstrator concept featured four configurations starting with a conventional combustion-powered multiengine airplane and ending with a fully electric configuration with two forms of distributed propulsion and a highly modified wing. These configurations, called Mods, were designed to gain incremental insight into different aircraft propulsion configuration options and their impact on the aircraft performance. The gasoline-powered Mod I configuration consumed 2.6 to 2.9 times more stored energy in cruise than the electric but otherwise conventionally configured Mod II configuration. The highly loaded wing of Mod III led to an increase of 40% in the power-off lift-to-drag ratio as compared to Mod II at the project high-speed cruise target speed and altitude. The power-on lift-to-drag ratio of Mod III was 53% higher than Mod II due to the beneficial aero-propulsive interaction of the wingtip-mounted cruise propellers in Mod III. The high-lift propeller system of Mod IV recovered the low-speed performance of the conventional configuration in Mod II that was otherwise lost with the introduction of the highly loaded Mod III wing. The battery-electric configurations also benefitted from a lack of power lapse in the electric motors with increasing air density as compared to the combustion-powered baseline aircraft.

Distributed Performance↗

Advanced Propfan Engine Technology (APET) definition study, single and counter-rotation gearbox/pitch change mechanism design

Single-rotation propfan-powered regional transport aircraft were studied to identify key technology development issues and programs. The need for improved thrust specific fuel consumption to reduce fuel burned and aircraft direct operating cost is the dominant factor. Typical cycle trends for minimizing fuel consumption are reviewed, and two 10,000 shp class engine configurations for propfan propulsion systems for the 1990's are presented. Recommended engine configurations are both three-spool design with dual spool compressors and free power turbines. The benefits of these new propulsion system concepts were evaluated using an advanced airframe, and results are compared for single-rotation propfan and turbofan advanced technology propulsion systems. The single-rotation gearbox is compared to a similar design with current technology to establish the benefits of the advanced gearbox technology. The conceptual design of the advanced pitch change mechanism identified a high pressure hydraulic system that is superior to the other contenders and completely external to the gearboxes.

Anderson, R. D.↗

Review of V/STOL lift/cruise fan technology

This paper presents an overview of supporting technology programs conducted to reduce the risk in the joint NASA/Navy Lift/Cruise Fan Research and Technology Aircraft Program. The aeronautical community has endeavored to combine the low-speed and lifting capabilities of the helicopter with the high-speed capabilities of the jet aircraft; recent developments have indicated a lift/cruise fan propulsion system may provide these desired characteristics. NASA and the Navy have formulated a program that will provide a research and technology aircraft to furnish viability of the lift/cruise fan aircraft through flight experiences and obtain data on designs for future naval and civil V/STOL aircraft. The supporting technology programs discussed include: (1) design studies for operational aircraft, a research and technology aircraft, and associated propulsion systems; (2) wind-tunnel tests of several configurations; (3) propulsion-system thrust vectoring tests; and (4) simulation. These supporting technology programs have indicated that a satisfactory research and technology aircraft program can be accomplished within the current level of technology.

Rolls, L. S.↗

Propulsion Airframe Integration Test Techniques for Hypersonic Airbreathing Configurations at NASA Langley Research Center

The scope and significance of propulsion airframe integration (PAI) for hypersonic airbreathing vehicles is presented through a discussion of the PAI test techniques utilized at NASA Langley Research Center. Four primary types of PAI model tests utilized at NASA Langley for hypersonic airbreathing vehicles are discussed. The four types of PAI test models examined are the forebody/inlet test model, the partial-width/truncated propulsion flowpath test model, the powered exhaust simulation test model, and the full-length/width propulsion flowpath test model. The test technique for each of these four types of PAI test models is described, and the relevant PAI issues addressed by each test technique are illustrated through the presentation of recent PAI test data.

Witte, David W.↗

Space fusion energy conversion using a field reversed configuration reactor: A new technical approach for space propulsion and power

The fusion energy conversion design approach, the Field Reversed Configuration (FRC) - when burning deuterium and helium-3, offers a new method and concept for space transportation with high energy demanding programs, like the Manned Mars Mission and planetary science outpost missions require. FRC's will increase safety, reduce costs, and enable new missions by providing a high specific power propulsion system from a high performance fusion engine system that can be optimally designed. By using spacecraft powered by FRC's the space program can fulfill High Energy Space Missions (HESM) in a manner not otherwise possible. FRC's can potentially enable the attainment of high payload mass fractions while doing so within shorter flight times.

Schulze, Norman R.↗

Flight Performance Maneuver Planning for NASA’s X-57 “Maxwell” Flight Demonstrator – Part 1: Power-Off Glides

Distributed Electric Propulsion technology is expected to yield up to a fivefold increase in high-speed cruise efficiency for NASA’s X-57 “Maxwell” flight demonstrator when compared to a combustion-powered general aviation baseline. A portion of this increased efficiency is due to beneficial aero-propulsive interaction inherent to the distributed propulsion architecture. The measure of the relative increase in efficiency between a conventional and distributed propulsion wing will be extracted from comparisons between flight test data from the electrically powered X-57 Mod II configuration with a conventional wing, and from the electrically powered X-57 Mod III/IV configuration with a distributed propulsion wing. Flight test maneuvers that accommodate errors in instrumentation and the flight test environment are developed to establish the power-off drag characteristics for all X-57 configurations. Analysis of these maneuvers with typical errors, including pilot-in-the-loop simulation data that incorporates simulated atmospheric turbulence effects, shows that the proposed power-off flight maneuvers can generate accurate power-off drag predictions for the X-57. These predictions show that the power-off differences in aerodynamic performance between the conventional and distributed propulsion configurations can be accurately measured from flight test data in the presence of typical data error sources.

Borer, Nicholas K.↗

Propulsion Airframe Aeroacoustics Technology Evaluation and Selection Using a Multi-Attribute Decision Making Process and Non-Deterministic Design

The Systems Analysis Branch at NASA Langley Research Center has investigated revolutionary Propulsion Airframe Aeroacoustics (PAA) technologies and configurations for a Blended-Wing-Body (BWB) type aircraft as part of its research for NASA s Quiet Aircraft Technology (QAT) Project. Within the context of the long-term NASA goal of reducing the perceived aircraft noise level by a factor of 4 relative to 1997 state of the art, major configuration changes in the propulsion airframe integration system were explored with noise as a primary design consideration. An initial down-select and assessment of candidate PAA technologies for the BWB was performed using a Multi-Attribute Decision Making (MADM) process consisting of organized brainstorming and decision-making tools. The assessments focused on what effect the PAA technologies had on both the overall noise level of the BWB and what effect they had on other major design considerations such as weight, performance and cost. A probabilistic systems analysis of the PAA configurations that presented the best noise reductions with the least negative impact on the system was then performed. Detailed results from the MADM study and the probabilistic systems analysis will be published in the near future.

Burg, Cecile M.↗

Propulsive-lift concepts for improved low-speed performance of supersonic cruise arrow-wing configurations

Low-aspect-ratio highly swept arrow-wing supersonic aircraft possess high levels of aerodynamic efficiency at supersonic cruising speeds, however, their inherently poor low-speed lift characteristics require design constraints that compromise supersonic performance. The data discussed in this paper were obtained in wind tunnel tests with supersonic crusing configurations, in which propulsive-lift concepts were used to improve low-speed performance. The data show that the increased low-speed lift provided by propulsive-lift permits reduction of both wing size and installed thrust. This yields a batter engine/airframe match for improved supersonic cruise efficiency and range, while still providing acceptable take-off field lengths.

Coe, P. L., Jr.↗

Propulsion and airframe aerodynamic interactions of supersonic V/STOL configurations, phase 1

A wind tunnel model of a supersonic V/STOL fighter configuration has been tested to measure the aerodynamic interaction effects which can result from geometrically close-coupled propulsion system/airframe components. The approach was to configure the model to present two different test techniques. One was a coventional test technique composed of two test modes. In the Flow-Through mode, absolute configuration aerodynamics are measured, including inlet/airframe interactions. In the Jet-Effects mode, incremental nozzle/airframe interactions are measured. The other test technique is a propulsion simulator approach, where a subscale, externally powered engine is mounted in the model. This allows proper measurement of inlet/airframe and nozzle/airframe interactions simultaneously.

Mraz, M. R.↗

Aeroelastic Wing Shaping Using Distributed Propulsion

An aircraft has wings configured to twist during flight. Inboard and outboard propulsion devices, such as turbofans or other propulsors, are connected to each wing, and are spaced along the wing span. A flight controller independently controls thrust of the inboard and outboard propulsion devices to significantly change flight dynamics, including changing thrust of outboard propulsion devices to twist the wing, and to differentially apply thrust on each wing to change yaw and other aspects of the aircraft during various stages of a flight mission. One or more generators can be positioned upon the wing to provide power for propulsion devices on the same wing, and on an opposite wing.

Nguyen, Nhan T.↗

Lunar and planetary landers for human exploration missions

This paper describes characteristics of lunar and planetary landers and mission profiles. Requirements are discussed, and propulsion and aerodynamic features are described. The paper covers recent history of concepts, configuration design drivers, propulsion, aerodynamics and aeroheating as applicable, structural and launch packaging factors, a summary of mission profiles, a description of the evolution of concepts, and reasons why the evolution has gone as it has.

Woodcock, Gordon↗

Ion propulsion for shared Shuttle, sun-synchronous missions

The configuration of an ion propulsion module (IPM) for use in the deployment and retrieval of sun-synchronous satellites on shared Shuttle flights is described. In addition to enabling shared Shuttle payloads requiring large orbital plane changes for achieving desired viewing conditions, the IPM makes over 10 kw available for payload power-sharing on orbit. The IPM also affords a large on-orbit propulsion capability. It has 2.8 x 10 to the 7th N-sec available at full propellant loading, of which less than half was needed for deploying and retrieving the representative spacecraft studied. Its remaining propulsion capability can be used for increasing payload or for additional propulsive functions on orbit.

Zafran, S.↗

Spacecraft mission and shielding thermal study for a space-storable fluorine-hydrazine propulsion system

The thermal management and shielding problems related to a space-storable fluorine-hydrazine propulsion system are investigated. The general configuration of a space storable propulsion spacecraft and three types of shield configurations are described in detail. An advanced MLI shielding design is proposed showing good agreement with test data. All examined shield configurations were found to be acceptable for inner as well as outer planetary missions. However, for the latter small local heaters may be required to maintain the fluorine above a minimum required temperature of approximately -350 F. The fluorine/hydrazine system with a 25 percent higher specific impulse than the conventionally used propulsion systems, was suggested for interplanetary missions that require substantial velocity changes.

Jones, J. A.↗

Configuration Management File Manager Developed for Numerical Propulsion System Simulation

One of the objectives of the High Performance Computing and Communication Project's (HPCCP) Numerical Propulsion System Simulation (NPSS) is to provide a common and consistent way to manage applications, data, and engine simulations. The NPSS Configuration Management (CM) File Manager integrated with the Common Desktop Environment (CDE) window management system provides a common look and feel for the configuration management of data, applications, and engine simulations for U.S. engine companies. In addition, CM File Manager provides tools to manage a simulation. Features include managing input files, output files, textual notes, and any other material normally associated with simulation. The CM File Manager includes a generic configuration management Application Program Interface (API) that can be adapted for the configuration management repositories of any U.S. engine company.

Follen, Gregory J.↗

An Air-Breathing Launch Vehicle Concept for Single-Stage-to-Orbit

The "Trailblazer" is a 300-lb payload, single-stage-to-orbit launch vehicle concept that uses air-breathing propulsion to reduce the required propellant fraction. The integration of air-breathing propulsion is done considering performance, structural and volumetric efficiency, complexity, and design risk. The resulting configuration is intended to be viable using near-term materials and structures. The aeropropulsion performance goal for the Trailblazer launch vehicle is an equivalent effective specific impulse (I*) of 500 sec. Preliminary analysis shows that this requires flight in the atmosphere to about Mach 10, and that the gross lift-off weight is 130,000 lb. The Trailblazer configuration and proposed propulsion system operating modes are described. Preliminary performance results are presented, and key technical issues are highlighted. An overview of the proposed program plan is given.

Trefny, Charles J.↗

NASA’s Electric Aircraft Propulsion Research: Yesterday, Today and Tomorrow

NASA has been making investments since ~2015 in technologies related to electric aircraft propulsion. These investments span all-electric with our four passenger X-plane and electric vertical lift studies, to regional flight demonstrators and targeted technology maturation programs. These latter two areas are focused ultimately on reducing fuel burn and overall energy use in transport-class aircraft, with the goal of reducing carbon impact of aviation on our planet. Key technology contributions include such as electric machines, power electronics, cables/bus bars, fault management systems, controls and systems studies, and enabling materials. Today we are seeing the fundamental technology investments manifest themselves in flight demonstrations, that are aimed at impacting aircraft entering service 2035-2040 time range. These efforts have largely been aimed at megawatt scale technologies that can enable hybrid electric or mildly distributed airplane concepts. While these concepts offer benefits to regional and single isle aircraft it is thought that a more fully electrified propulsion system requiring greater than 10 MW of distributed power offers more possible pathways to configure the propulsion-airframe system to gain new efficiencies. A few examples of this are NASA’s SUSAN distributed electrofan concept and NASA University Leadership Initiatives such as CHEETA and IZEA that champion turbo-electric concepts. These concepts utilize combination of advanced technologies such as, fuel cells, power dense electronics and power dense electric machines and superconducting technologies. How much or which of these concepts will be adopted by industry is unclear, however another step function in electrifying aircraft propulsion is now on the horizon.

Electric Aircraft Propulsion↗

The Marshall Magnetic Mirror Beam-Plasma Experiment

Plasma propulsion is an advanced propulsion concept with the potential to realize very high specific impulse. Present designs for plasma propulsion devices share a common feature, the incorporation of a magnetic mirror. A magnetic mirror is a plasma confinement scheme whereby charged particles are trapped (or reflected) between two regions of high magnetic field strength. A cylindrical geometry is most often employed to create a magnetic mirror, which is a natural geometry for propulsion devices. To utilize the magnetic mirror configuration in a plasma propulsion device, however, will require efficient coupling of power into the system. With the development of compact and efficient electron sources, such as hollow cathode sources, coupling power into a magnetic mirror using electron beams may be an attractive approach. A system, the Marshall Magnetic Mirror (M3), has been constructed to study the coupling of an electron beam into a magnetic mirror. A description of the M3 device will be provided as well as data from initial beam-plasma coupling experiments.

Schneider, Todd A.↗

V/STOL systems research aircraft: A tool for cockpit integration

The next generation ASTOVL aircraft will have a complicated propulsion system. The configuration choices include Direct Lift, Lift-Fan and Lift + Lift/Cruise but the aircraft must also have supersonic performance and low-observable characteristics. The propulsion system may have features such as flow blockers, vectoring nozzles and flow transfer schemes. The flight control system will necessarily fully integrate the aerodynamic surfaces and the propulsive elements. With a fully integrated, fly-by-wire flight/propulsion control system, the options for cockpit integration are interesting and varied. It is possible to de-couple longitudinal and vertical responses allowing the pilot to close the loop on flightpath and flightpath acceleration directly. In the hover, the pilot can control the translational rate directly without having to stabilize the inner rate and attitude loops. The benefit of this approach, reduced workload and increased precision, has previously been demonstrated through several motion-based simulations. In order to prove the results in flight, the V/STOL System Research Aircraft (VSRA) was developed at the NASA Ames Research Center. The VSRA is the YAV-8B Prototype modified with a research flight control system using a series-parallel servo configuration in all the longitudinal degrees of freedom (including thrust and thrust vector angle) to provide an integrated flight and propulsion control system in a limited envelope. Development of the system has been completed and flight evaluations of the response types have been performed. In this paper we will discuss the development of the VSRA, the evolution of the flightpath command and translational rate command response types and the Guest Pilot evaluations of the system. Pilot evaluation results are used to draw conclusions regarding the suitability of the system to satisfy V/STOL requirements.

Stortz, Michael W.↗