Search NASA⌕ Search

SEARCH · Search NASA

Results for “Advanced Fuel”

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 NTRS1995

Hybrid fuel formulation and technology development

The objective was to develop an improved hybrid fuel with higher regression rate, a regression rate expression exponent close to 0.5, lower cost, and higher density. The approach was to formulate candidate fuels based on promising concepts, perform thermomechanical analyses to select the most promising candidates, develop laboratory processes to fabricate fuel grains as needed, fabricate fuel grains and test in a small lab-scale motor, select the best candidate, and then scale up and validate performance in a 2500 lbf scale, 11-inch diameter motor. The characteristics of a high performance fuel have been verified in 11-inch motor testing. The advanced fuel exhibits a 15% increase in density over an all hydrocarbon formulation accompanied by a 50% increase in regression rate, which when multiplied by the increase in density yields a 70% increase in fuel mass flow rate; has a significantly lower oxidizer-to-fuel (O/F) ratio requirement at 1.5; has a significantly decreased axial regression rate variation making for more uniform propellant flow throughout motor operation; is very clean burning; extinguishes cleanly and quickly; and burns with a high combustion efficiency.

Dean, D. L.↗
NASA NTRSDate not supplied

CFD Evaluation of Sustainable Aviation Fuel Blends for Commercial Supersonics Technology

An overview is provided of a CFD assessment with advanced fuel blends to assess fuel impacts on NOx emissions and flame structure in an axially-staged combustor for NASA’s Commercial Supersonic Transport (CST) Program. The National Combustor Code (OpenNCC) was used to perform two-phase reacting flow computations with various blending ratios of two different aviation fuels, ‘average’ Jet-A (A2) and GEVO-ATJ (C1), for UTRC’s Axially Controlled Stoichiometry (ACS) combustor at CST cruise conditions. The predicted flame structures in the ACS combustor with three different blending ratios of A2 and C1 fuel were very similar to each other. The predicted NOx emissions for all fuel blends were within 10% of the experimentally measured NOx emissions for 100% A2 fuel.

Gas Turbine Combustion↗
NASA NTRS1981

Develop and test fuel cell powered on-site integrated total energy system. Phase 3: Full-scale power plant development

An integrated 5 kW power system based upon methanol fuel and a phosphoric acid fuel cell operating at about 473 K is described. Description includes test results of advanced fuel cell catalysts, a semiautomatic acid replenishment system and a completed 5 kW methanol/system reformer. The results of a preliminary system test on a reformer/stack/inverter combination are reported. An initial design for a 25 kW stack is presented. Experimental plans are outlined for data acquisition necessary for design of a 50 kW methanol/steam reformer. Activities related to complete mathematical modelling of the integrated power system, including wasteheat utilization, are described.

Kaufman, A.↗
NASA NTRS1987

High temperature electrolyzer/fuel cell power cycle: Preliminary design considerations

A model of a high temperature electrolyzer/fuel cell, hydrogen/oxygen, thermally regenerative power cycle is developed and used to simulate system performance for varying system parameters. Initial estimates of system efficiency, weight, and volume are provided for a one KWe module assuming specific electrolyzer and fuel cell characteristics, both current and future. Specific interest is placed on examining the system responses to changes in device voltage versus current density operating curves, and the associated optimum operating ranges. The performance of a solar-powered, space based system in low earth orbit is examined in terms of the light-dark periods requiring storage. The storage design tradeoffs between thermal energy, electrical energy, and hydrogen/oxygen mass storage are examined. The current technology module is based on the 1000 C solid oxide electrolyzer cell and the alkaline fuel cell. The Future Technology system examines benefits involved with developing a 1800K electrolyzer operating with an advanced fuel cell.

Morehouse, Jeffrey H.↗
NASA NTRS1978

Carbon Monoxide Sensor

The fuel cell is a system which employs an electrochemical process to convert gases- J such as hydrogen and oxygen directly into electricity. Under NASA sponsorship, GE's Aircraft Equipment Division developed fuel cells to supply electrical power for the Gemini and Biosatellite spacecraft of the sixties and is currently working on advanced fuel cell development. This long-term effort has resulted in a series of spinoff applications using the same general technology for a variety of purposes, among them the recently marketed Dosimeter. The Dosimeter is designed to help users meet safety requirements for industrial atmospheres, as specified by the Occupational Safety and Health Administration and other regulatory agencies. The compact, pocket-sized sensor measures personnel exposure to carbon monoxide and provides both a visual and an audible alarm if the concentration of the gas exceeds present levels. The Dosimeter offers substantial improvement in measuring accuracy over earlier warning indicators.

Source record↗
NASA NTRS2011

Non-Nuclear Testing of Fission Technologies at NASA MSFC

Highly realistic non-nuclear testing can be used to investigate and resolve potential issues with space nuclear power and propulsion systems. Non-nuclear testing is particularly useful for systems designed with fuels and materials operating within their demonstrated nuclear performance envelope. Non-nuclear testing also provides an excellent way for screening potential advanced fuels and materials prior to nuclear testing, and for investigating innovative geometries and operating regimes. Non-nuclear testing allows thermal hydraulic, heat transfer, structural, integration, safety, operational, performance, and other potential issues to be investigated and resolved with a greater degree of flexibility and at reduced cost and schedule compared to nuclear testing. The primary limit of non-nuclear testing is that nuclear characteristics and potential nuclear issues cannot be directly investigated. However, non-nuclear testing can be used to augment the potential benefit from any nuclear testing that may be required for space nuclear system design and development. This paper describes previous and ongoing non-nuclear testing related to space nuclear systems at NASA s Marshall Space Flight Center (MSFC).

Houts, Robert G.↗
NASA NTRS1972

Status of shuttle fuel cell technology program.

The hydrogen-oxygen fuel cell has been proved as an efficient and reliable electrical power supply for NASA manned-space-flight vehicles. It has thus ensured a role in the Space Shuttle Program as the primary electrical power supply for the Orbiter vehicle. The advanced fuel cell technology programs conducted under the management of the NASA Manned Spacecraft Center over the past two years have resulted in a high level of technical readiness in fuel cell power generation to support shuttle mission requirements. These programs have taken advantage of technological developments that have occurred since the designs were completed for the Gemini and Apollo fuel cells.

Rice, W. E.↗
NASA NTRS1990

Stochastic Feedforward Control Technique

Class of commanded trajectories modeled as stochastic process. Advanced Transport Operating Systems (ATOPS) research and development program conducted by NASA Langley Research Center aimed at developing capabilities for increases in capacities of airports, safe and accurate flight in adverse weather conditions including shear, winds, avoidance of wake vortexes, and reduced consumption of fuel. Advances in techniques for design of modern controls and increased capabilities of digital flight computers coupled with accurate guidance information from Microwave Landing System (MLS). Stochastic feedforward control technique developed within context of ATOPS program.

Halyo, Nesim↗
NASA NTRS2002

Fuel Cell Activities at the NASA Glenn Research Center

Fuel cells have a long history in space applications and may have potential application in aeronautics as well. A fuel cell is an electrochemical energy conversion device that directly transforms the chemical energy of a fuel and oxidant into electrical energy. Alkaline fuel cells have been the mainstay of the U.S. space program, providing power for the Apollo missions and the Space Shuttle. However, Proton Exchange Membrane (PEM) fuel cells offer potential benefits over alkaline systems and are currently under development for the next generation Reusable Launch Vehicle (RLV). Furthermore, primary and regenerative systems utilizing PEM technology are also being considered for future space applications such as surface power and planetary aircraft. In addition to these applications, the NASA Glenn Research Center is currently studying the feasibility of the use of both PEM and solid oxide fuel cells for low- or zero-emission electric aircraft propulsion. These types of systems have potential applications for high altitude environmental aircraft, general aviation and commercial aircraft, and high attitude airships. NASA Glenn has a unique set of capabilities and expertise essential to the successful development of advanced fuel cell power systems for space and aeronautics applications. NASA Glenn's role in past fuel cell development programs as well as current activities to meet these new challenges will be presented

Kohout, Lisa L.↗
NASA NTRS1988

Aircraft engines. III

Prospective powerplant configuration advancements for tilt-rotor subsonic flight, supersonic commercial flight, and hypersonic flight are speculated upon, with a view to possibilities for the exploitation of novel materials and of such advanced fuels as liquid methane and hydrogen. Attention is given to the foldable tilt-rotor concept, which employs a hydraulic torque converter to engage the fan stage of the high-bypass turbofan engine used in forward flight after the tilt-rotor blades have been stowed, and several advanced cycles and turbomechanical configurations for cruise in the high supersonic regime and beyond, through the hypersonic regime, and into orbital velocity.

Mikkelson, Daniel C.↗
NASA NTRS2016

Stirling to Flight Initiative

NASA has a consistent need for radioisotope power systems (RPS) to enable robotic scientific missions for planetary exploration that has been present for over four decades and will continue into the foreseeable future, as documented in the most recent Planetary Science Decadal Study Report. As RPS have evolved throughout the years, there has also grown a desire for more efficient power systems, allowing NASA to serve as good stewards of the limited plutonium-238 (238Pu), while also supporting the ever-present need to minimize mass and potential impacts to the desired science measurements. In fact, the recent Nuclear Power Assessment Study (NPAS) released in April 2015 resulted in several key conclusion regarding RPS, including affirmation that RPS will be necessary well into the 2030s (at least) and that 238Pu is indeed a precious resource requiring efficient utilization and preservation. Stirling Radioisotope Generators (SRGs) combine a Stirling cycle engine powered by a radioisotope heater unit into a single generator system. Stirling engine technology has been under development at NASA Glenn Research Center (GRC) in partnership with the Department of Energy (DOE) since the 1970's. The most recent design, the 238Pu-fueled Advanced Stirling Radioisotope Generator (ASRG), was offered as part of the NASA Discovery 2010 Announcement of Opportunity (AO). The Step-2 selections for this AO included two ASRG-enabled concepts, the Titan Mare Explorer (TiME) and the Comet Hopper (CHopper), although the only non-nuclear concept, InSight, was ultimately chosen. The DOE's ASRG contract was terminated in 2013. Given that SRGs utilize significantly less 238Pu than traditional Radioisotope Thermoelectric Generators (RTGs) - approximately one quarter of the nuclear fuel, to produce similar electrical power output - they provide a technology worthy of consideration for meeting the aforementioned NASA objectives. NASA's RPS Program Office has recently investigated a new Stirling to Flight (S2F) initiative with the objective of developing a 100-500 We Stirling generator system. Additionally, a different approach is being devised for this initiative to avoid pitfalls of the past, and apply lessons learned from the recent ASRG experience. Two key aspects of this initiative are a Stirling System Technology Maturation Effort, and a Surrogate Mission Team (SMT) intended to provide clear mission pull and requirements context. The S2F project seeks to lead directly into a DOE flight system development of a new SRG. This paper will detail the proposed S2F initiative, and provide specifics on the key efforts designed to pave a forward path for bringing Stirling technology to flight.

Robotics↗
NASA NTRS1972

A fuel conservation study for transport aircraft utilizing advanced technology and hydrogen fuel

The conservation of fossil fuels in commercial aviation was investigated. Four categories of aircraft were selected for investigation: (1) conventional, medium range, low take-off gross weight; (2) conventional, long range, high take-off gross weights; (3) large take-off gross weight aircraft that might find future applications using both conventional and advanced technology; and (4) advanced technology aircraft of the future powered with liquid hydrogen fuel. It is concluded that the hydrogen fueled aircraft can perform at reduced size and gross weight the same payload/range mission as conventionally fueled aircraft.

Berry, W.↗
NASA NTRS2003

Propulsion Research at the Propulsion Research Center of the NASA Marshall Space Flight Center

The Propulsion Research Center of the NASA Marshall Space Flight Center is engaged in research activities aimed at providing the bases for fundamental advancement of a range of space propulsion technologies. There are four broad research themes. Advanced chemical propulsion studies focus on the detailed chemistry and transport processes for high-pressure combustion, and on the understanding and control of combustion stability. New high-energy propellant research ranges from theoretical prediction of new propellant properties through experimental characterization propellant performance, material interactions, aging properties, and ignition behavior. Another research area involves advanced nuclear electric propulsion with new robust and lightweight materials and with designs for advanced fuels. Nuclear electric propulsion systems are characterized using simulated nuclear systems, where the non-nuclear power source has the form and power input of a nuclear reactor. This permits detailed testing of nuclear propulsion systems in a non-nuclear environment. In-space propulsion research is focused primarily on high power plasma thruster work. New methods for achieving higher thrust in these devices are being studied theoretically and experimentally. Solar thermal propulsion research is also underway for in-space applications. The fourth of these research areas is advanced energetics. Specific research here includes the containment of ion clouds for extended periods. This is aimed at proving the concept of antimatter trapping and storage for use ultimately in propulsion applications. Another activity in this involves research into lightweight magnetic technology for space propulsion applications.

Blevins, John↗
NASA NTRS1978

Fuel consumption improvement in current transport engines

A review is conducted of improvements which can be made with respect to the fuel consumption of current engines and new production versions of current engines. A description is presented of an engine diagnostics program which has the objective to identify and quantify the causes and sources of performance deterioration in the JT9D turbofan engine and to develop basic data which will be applied to minimize performance degradation of current and future engines. General areas where performance losses occur are examined, taking into account seals, blades and vanes, and cases. Potential performance improvement concepts are related to improved component aerodynamics, improved flowpath sealing, blade tip clearance control, improved turbine cooling effectiveness, improved turbine materials and coatings, duct and nozzle aerodynamic refinements, nacelle aerodynamic refinements, forced exhaust mixers, advanced nacelle materials, and advanced fuel control.

Hines, R. W.↗
NASA NTRS1983

Energy Efficient Engine Flight Propulsion System Preliminary Analysis and Design Report

The final design and analysis of the flight propulsion system is presented. This system is the conceptual study engine defined to meet the performance, economic and environmental goals established for the Energy Efficient Engine Program. The design effort included a final definition of the engine, major components, internal subsystems, and nacelle. Various analytical representations and results from component technology programs are used to verify aerodynamic and structural design concepts and to predict performance. Specific design goals and specifications, reflecting future commercial aircraft propulsion system requirements for the mid-1980's, are detailed by NASA and used as guidelines during engine definition. Information is also included which details salient results from a separate study to define a turbofan propulsion system, known as the maximum efficiency engine, which reoptimized the advanced fuel saving technologies for improved fuel economy and direct operating costs relative to the flight propulsion system.

Bisset, J. W.↗
NASA NTRS1990

Effect of vane twist on the performance of dome swirlers for gas turbine airblast atomizers

For advanced gas turbine engines, two combustor systems, the lean premixed/prevaporized (LPP) and the rich burn/quick quench/lean burn (RQL) offer great potential for reducing NO(x) emissions. An important consideration for either concept is the development of an advanced fuel injection system that will provide a stable, efficient, and very uniform combustion system over a wide operating range. High-shear airblast fuel injectors for gas turbine combustors have exhibited superior atomization and mixing compared with pressure-atomizing fuel injectors. This improved mixing has lowered NO(x) emissions and the pattern factor, and has enabled combustors to alternate fuels while maintaining a stable, efficient combustion system. The performance of high-shear airblast fuel injectors is highly dependent on the design of the dome swirl vanes. The type of swirl vanes most widely used in gas turbine combustors are usually flat for ease of manufacture, but vanes with curvature will, in general, give superior aerodynamic performance. The design and performance of high-turning, low-loss curved dome swirl vanes with twist along the span are investigated. The twist induces a secondary vortex flow pattern which will improve the atomization of the fuel, thereby producing a more uniform fuel-air distribution. This uniform distribution will increase combustion efficiency while lowering NO(x) emissions. A systematic swirl vane design system is presented based on one-, two-, and three-dimensional flowfield calculations, with variations in vane-turning angle, rate of turning, vane solidity, and vane twist as design parameters.

Micklow, Gerald J.↗