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  • 1
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    Development of a Solid-Oxide Fuel Cell/Gas Turbine Hybrid System Model for Aerospace Applications (2004)
    In:  CASI
    Details
    Publikationsdatum: 2019-07-13
    Beschreibung: Recent interest in fuel cell-gas turbine hybrid applications for the aerospace industry has led to the need for accurate computer simulation models to aid in system design and performance evaluation. To meet this requirement, solid oxide fuel cell (SOFC) and fuel processor models have been developed and incorporated into the Numerical Propulsion Systems Simulation (NPSS) software package. The SOFC and reformer models solve systems of equations governing steady-state performance using common theoretical and semi-empirical terms. An example hybrid configuration is presented that demonstrates the new capability as well as the interaction with pre-existing gas turbine and heat exchanger models. Finally, a comparison of calculated SOFC performance with experimental data is presented to demonstrate model validity. Keywords: Solid Oxide Fuel Cell, Reformer, System Model, Aerospace, Hybrid System, NPSS
    Schlagwort(e): Computer Programming and Software
    Materialart: NASA/TM-2004-213054 , GT2004-53616 , E-14490 , Turbo Expo 2004; Jun 14, 2004 - Jun 17, 2004; Vienna; Austria
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
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    NASA TECHNICAL REPORTS
  • 2
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    Low-Latency Teleoperations for Human Exploration and Evolvable Mars Campaign (2015)
    In:  CASI
    Details
    Publikationsdatum: 2019-08-14
    Beschreibung: NASA has been analyzing a number of mission concepts and activities that involve low-latency telerobotic (LLT) operations. One mission concept that will be covered in this presentation is Crew-Assisted Sample Return which involves the crew acquiring samples (1) that have already been delivered to space, and or acquiring samples via LLT from orbit to a planetary surface and then launching the samples to space to be captured in space and then returned to the earth with the crew. Both versions of have key roles for low-latency teleoperations. More broadly, the NASA Evolvable Mars Campaign is exploring a number of other activities that involve LLT, such as: (a) human asteroid missions, (b) PhobosDeimos missions, (c) Mars human landing site reconnaissance and site preparation, and (d) Mars sample handling and analysis. Many of these activities could be conducted from Mars orbit and also with the crew on the Mars surface remotely operating assets elsewhere on the surface, e.g. for exploring Mars special regions and or teleoperating a sample analysis laboratory both of which may help address planetary protection concerns. The operational and technology implications of low-latency teleoperations will be explored, including discussion of relevant items in the NASA Technology Roadmap and also how previously deployed robotic assets from any source could subsequently be used by astronauts via LLT.
    Schlagwort(e): Lunar and Planetary Science and Exploration
    Materialart: GSFC-E-DAA-TN23785 , SpaceOps 2015 Workshop; Jun 10, 2015 - Jun 12, 2015; Rome; Italy
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 3
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    System Modeling of Lunar Oxygen Production: Mass and Power Requirements (2007)
    In:  CASI
    Details
    Publikationsdatum: 2019-07-13
    Beschreibung: A systems analysis tool for estimating the mass and power requirements for a lunar oxygen production facility is introduced. The individual modeling components involve the chemical processing and cryogenic storage subsystems needed to process a beneficiated regolith stream into liquid oxygen via ilmenite reduction. The power can be supplied from one of six different fission reactor-converter systems. A baseline system analysis, capable of producing 15 metric tons of oxygen per annum, is presented. The influence of reactor-converter choice was seen to have a small but measurable impact on the system configuration and performance. Finally, the mission concept of operations can have a substantial impact upon individual component size and power requirements.
    Schlagwort(e): Nuclear Physics
    Materialart: Paper 2049 , E-18266 , Space Nuclear Power Conference 2007; Jun 24, 2007 - Jun 28, 2007; Boston, MA; United States
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
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    NASA TECHNICAL REPORTS
  • 4
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    An Analytical Performance Assessment of a Fuel Cell-powered, Small Electric Airplane (2003)
    In:  CASI
    Details
    Publikationsdatum: 2019-07-13
    Beschreibung: 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 exception of water vapor zero emissions. This paper describes an analytical feasibility and performance assessment conducted by NASA's Glenn Research Center of a fuel cell-powered, propeller-driven, small electric airplane based on a model of the MCR 01 two-place kitplane.
    Schlagwort(e): Propellants and Fuels
    Materialart: NASA/TM-2003-212393 , NAS1.15.212393 , E-13972 , Novel Vehicle Concepts and Emerging Vehicle Technologies Symposium; Apr 07, 2003 - Apr 10, 2003; Brussels; Belgium
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 5
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    Electrical Systems Analysis at NASA Glenn Research Center: Status and Prospects (2003)
    In:  CASI
    Details
    Publikationsdatum: 2019-07-13
    Beschreibung: An analysis of an electrical power and propulsion system for a 2-place general aviation aircraft is presented to provide a status of such modeling at NASA Glenn Research Center. The thermodynamic/ electrical model and mass prediction tools are described and the resulting system power and mass are shown. Three technology levels are used to predict the effect of advancements in component technology. Methods of fuel storage are compared by mass and volume. Prospects for future model development and validation at NASA as well as possible applications are also summarized.
    Schlagwort(e): Aircraft Propulsion and Power
    Materialart: NASA/TM-2003-212520 , E-14082 , NAS 1.15:212520 , Novel Vehicle Concepts and Emerging Vehicle Technologies Symposium; Apr 07, 2003 - Apr 10, 2003; Brussels; Belgium
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 6
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    Development of Parametric Mass and Volume Models for an Aerospace SOFC/Gas Turbine Hybrid System (2005)
    In:  CASI
    Details
    Publikationsdatum: 2019-07-13
    Beschreibung: In aerospace power systems, mass and volume are key considerations to produce a viable design. The utilization of fuel cells is being studied for a commercial aircraft electrical power unit. Based on preliminary analyses, a SOFC/gas turbine system may be a potential solution. This paper describes the parametric mass and volume models that are used to assess an aerospace hybrid system design. The design tool utilizes input from the thermodynamic system model and produces component sizing, performance, and mass estimates. The software is designed such that the thermodynamic model is linked to the mass and volume model to provide immediate feedback during the design process. It allows for automating an optimization process that accounts for mass and volume in its figure of merit. Each component in the system is modeled with a combination of theoretical and empirical approaches. A description of the assumptions and design analyses is presented.
    Schlagwort(e): Aircraft Propulsion and Power
    Materialart: NASA/TM-2005-213819 , GT2005-68334 , E-15177 , Turbo Expo 2005; Jun 06, 2005 - Jun 09, 2005; Reno, NV; United States
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
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    NASA TECHNICAL REPORTS
  • 7
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    Solid Oxide Fuel Cell/Gas Turbine Hybrid Cycle Technology for Auxiliary Aerospace Power (2005)
    In:  CASI
    Details
    Publikationsdatum: 2019-07-13
    Beschreibung: A notional 440 kW auxiliary power unit has been developed for 300 passenger commercial transport aircraft in 2015AD. A hybrid engine using solid-oxide fuel cell stacks and a gas turbine bottoming cycle has been considered. Steady-state performance analysis during cruise operation has been presented. Trades between performance efficiency and system mass were conducted with system specific energy as the discriminator. Fuel cell performance was examined with an area specific resistance. The ratio of fuel cell versus turbine power was explored through variable fuel utilization. Area specific resistance, fuel utilization, and mission length had interacting effects upon system specific energy. During cruise operation, the simple cycle fuel cell/gas turbine hybrid was not able to outperform current turbine-driven generators for system specific energy, despite a significant improvement in system efficiency. This was due in part to the increased mass of the hybrid engine, and the increased water flow required for on-board fuel reformation. Two planar, anode-supported cell design concepts were considered. Designs that seek to minimize the metallic interconnect layer mass were seen to have a large effect upon the system mass estimates.
    Schlagwort(e): Aircraft Propulsion and Power
    Materialart: NASA/TM?2005-213586 , GT2005?68619 , E?15053 , Turbo Expo 2005; Jun 06, 2005 - Jun 09, 2005; Reno, NV; United States
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
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    NASA TECHNICAL REPORTS
  • 8
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    Comparison of Solar Electric and Chemical Propulsion Missions (2015)
    In:  CASI
    Details
    Publikationsdatum: 2019-07-13
    Beschreibung: Solar Electric Propulsion (SEP) offers fuel efficiency and mission robustness for spacecraft. The combination of solar power and electric propulsion engines is currently used for missions ranging from geostationary stationkeeping to deep space science because of these benefits. Both solar power and electric propulsion technologies have progressed to the point where higher electric power systems can be considered, making substantial cargo missions and potentially human missions viable. This paper evaluates and compares representative lunar, Mars, and Sun-Earth Langrangian point missions using SEP and chemical propulsion subsystems. The potential benefits and limitations are discussed along with technology gaps that need to be resolved for such missions to become possible. The connection to NASA's human architecture and technology development efforts will be discussed.
    Schlagwort(e): Spacecraft Propulsion and Power
    Materialart: IAC-15-D1.4.3 , GRC-E-DAA-TN26989 , International Astronautical Congress (IAC 2015); Oct 12, 2015 - Oct 16, 2015; Jerusalem; Israel
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 9
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    Propulsion Investigation for Zero and Near-Zero Emissions Aircraft (2009)
    In:  CASI
    Details
    Publikationsdatum: 2019-07-12
    Beschreibung: As world emissions are further scrutinized to identify areas for improvement, aviation s contribution to the problem can no longer be ignored. Previous studies for zero or near-zero emissions aircraft suggest aircraft and propulsion system sizes that would perform propulsion system and subsystems layout and propellant tankage analyses to verify the weight-scaling relationships. These efforts could be used to identify and guide subsequent work on systems and subsystems to achieve viable aircraft system emissions goals. Previous work quickly focused these efforts on propulsion systems for 70- and 100-passenger aircraft. Propulsion systems modeled included hydrogen-fueled gas turbines and fuel cells; some preliminary estimates combined these two systems. Hydrogen gas-turbine engines, with advanced combustor technology, could realize significant reductions in nitrogen emissions. Hydrogen fuel cell propulsion systems were further laid out, and more detailed analysis identified systems needed and weight goals for a viable overall system weight. Results show significant, necessary reductions in overall weight, predominantly on the fuel cell stack, and power management and distribution subsystems to achieve reasonable overall aircraft sizes and weights. Preliminary conceptual analyses for a combination of gas-turbine and fuel cell systems were also performed, and further studies were recommended. Using gas-turbine engines combined with fuel cell systems can reduce the fuel cell propulsion system weight, but at higher fuel usage than using the fuel cell only.
    Schlagwort(e): Aircraft Propulsion and Power
    Materialart: NASA/TM-2009-215487 , E-16693
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 10
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    Off-Design Performance Analysis of a Solid-Oxide Fuel Cell/Gas Turbine Hybrid for Auxiliary Aerospace Power (2005)
    In:  CASI
    Details
    Publikationsdatum: 2019-07-11
    Beschreibung: A solid-oxide fuel cell/gas turbine hybrid system for auxiliary aerospace power is analyzed using 0-D and 1-D system-level models. The system is designed to produce 440 kW of net electrical power, sized for a typical long-range 300-passenger civil airplane, at both sea level and cruise flight level (12,500 m). In addition, a part power level of 250 kW is analyzed at the cruise condition, a requirement of the operating power profile. The challenge of creating a balanced system for the three distinct conditions is presented, along with the compromises necessary for each case. A parametric analysis is described for the cruise part power operating point, in which the system efficiency is maximized by varying the air flow rate. The system is compared to an earlier version that was designed solely for cruise operation. The results show that it is necessary to size the turbomachinery, fuel cell, and heat exchangers at sea level full power rather than cruise full power. The resulting estimated mass of the system is 1912 kg, which is significantly higher than the original cruise design point mass, 1396 kg. The net thermal efficiencies with respect to the fuel LHV are calculated to be 42.4 percent at sea level full power, 72.6 percent at cruise full power, and 72.8 percent at cruise part power. The cruise conditions take advantage of pre-compressed air from the on-board Environmental Control System, which accounts for a portion of the unusually high thermal efficiency at those conditions. These results show that it is necessary to include several operating points in the overall assessment of an aircraft power system due to the variations throughout the operating profile.
    Schlagwort(e): Propellants and Fuels
    Materialart: NASA/TM-2005-213805 , E-15163 , FUELCELL2005-74099
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
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