Science.gov

Sample records for aircraft fuel burn

  1. Aircraft Engine Technology for Green Aviation to Reduce Fuel Burn

    NASA Technical Reports Server (NTRS)

    Hughes, Christopher E.; VanZante, Dale E.; Heidmann, James D.

    2013-01-01

    The NASA Fundamental Aeronautics Program Subsonic Fixed Wing Project and Integrated Systems Research Program Environmentally Responsible Aviation Project in the Aeronautics Research Mission Directorate are conducting research on advanced aircraft technology to address the environmental goals of reducing fuel burn, noise and NOx emissions for aircraft in 2020 and beyond. Both Projects, in collaborative partnerships with U.S. Industry, Academia, and other Government Agencies, have made significant progress toward reaching the N+2 (2020) and N+3 (beyond 2025) installed fuel burn goals by fundamental aircraft engine technology development, subscale component experimental investigations, full scale integrated systems validation testing, and development validation of state of the art computation design and analysis codes. Specific areas of propulsion technology research are discussed and progress to date.

  2. Technologies and Concepts for Reducing the Fuel Burn of Subsonic Transport Aircraft

    NASA Technical Reports Server (NTRS)

    Nickol, Craig L.

    2012-01-01

    There are many technologies under development that have the potential to enable large fuel burn reductions in the 2025 timeframe for subsonic transport aircraft relative to the current fleet. This paper identifies a potential technology suite and analyzes the fuel burn reduction potential of these technologies when integrated into advanced subsonic transport concepts. Advanced tube-and-wing concepts are developed in the single aisle and large twin aisle class, and a hybrid-wing-body concept is developed for the large twin aisle class. The resulting fuel burn reductions for the advanced tube-and-wing concepts range from a 42% reduction relative to the 777-200 to a 44% reduction relative to the 737-800. In addition, the hybrid-wingbody design resulted in a 47% fuel burn reduction relative to the 777-200. Of course, to achieve these fuel burn reduction levels, a significant amount of technology and concept maturation is required between now and 2025. A methodology for capturing and tracking concept maturity is also developed and presented in this paper.

  3. 14 CFR 33.79 - Fuel burning thrust augmentor.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Fuel burning thrust augmentor. 33.79... AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.79 Fuel burning thrust augmentor. Each fuel burning thrust augmentor, including the nozzle, must— (a) Provide cutoff...

  4. 14 CFR 33.79 - Fuel burning thrust augmentor.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Fuel burning thrust augmentor. 33.79... AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.79 Fuel burning thrust augmentor. Each fuel burning thrust augmentor, including the nozzle, must— (a) Provide cutoff...

  5. 14 CFR 33.79 - Fuel burning thrust augmentor.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Fuel burning thrust augmentor. 33.79... AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.79 Fuel burning thrust augmentor. Each fuel burning thrust augmentor, including the nozzle, must— (a) Provide cutoff...

  6. Alternative jet aircraft fuels

    NASA Technical Reports Server (NTRS)

    Grobman, J.

    1979-01-01

    Potential changes in jet aircraft fuel specifications due to shifts in supply and quality of refinery feedstocks are discussed with emphasis on the effects these changes would have on the performance and durability of aircraft engines and fuel systems. Combustion characteristics, fuel thermal stability, and fuel pumpability at low temperature are among the factors considered. Combustor and fuel system technology needs for broad specification fuels are reviewed including prevention of fuel system fouling and fuel system technology for fuels with higher freezing points.

  7. Multimission Fuel-Burn Minimization in Aircraft Design: A Surrogate-Modeling Approach

    NASA Astrophysics Data System (ADS)

    Liem, Rhea Patricia

    Aerodynamic shape and aerostructural design optimizations that maximize the performance at a single flight condition result in designs with unacceptable off-design performance. While considering multiple flight conditions in the optimization improves the robustness of the designs, there is a need to develop a rational strategy for choosing the flight conditions and their relative emphases such that multipoint optimizations reflect the true objective function. In addition, there is a need to consider uncertain missions and flight conditions. In this thesis, the strategies to formulate the multipoint objective functions for aerodynamic shape and aerostructural optimization are presented. To determine the flight conditions and their corresponding weights, a novel surrogate-based mission analysis is developed to efficiently analyze hundreds of actual mission data to emulate their flight-condition distribution. Using accurate and reliable surrogate models to approximate the aerodynamic coefficients used in the analysis makes this procedure computationally tractable. A mixture of experts (ME) approach is developed to overcome the limitations of conventional surrogate models in modeling the complex transonic drag profile. The ME approach combines multiple surrogate models probabilistically based on the divide-and-conquer strategy. Using this model in the mission analysis significantly improves the range estimation accuracy, as compared to other conventional surrogate models. As expected, the multipoint aerodynamic shape and aerostructural optimizations demonstrate a consistent drag reduction, instead of the localized improvement by the single-point optimizations. The improved robustness in the multipoint optimized designs was also observed in terms of the improved range performance and more consistent fuel-burn reduction across the different missions. The results presented in this thesis show that the surrogate-model-assisted multipoint optimization produces a robust

  8. Multimission Fuel-Burn Minimization in Aircraft Design: A Surrogate-Modeling Approach

    NASA Astrophysics Data System (ADS)

    Liem, Rhea Patricia

    Aerodynamic shape and aerostructural design optimizations that maximize the performance at a single flight condition result in designs with unacceptable off-design performance. While considering multiple flight conditions in the optimization improves the robustness of the designs, there is a need to develop a rational strategy for choosing the flight conditions and their relative emphases such that multipoint optimizations reflect the true objective function. In addition, there is a need to consider uncertain missions and flight conditions. In this thesis, the strategies to formulate the multipoint objective functions for aerodynamic shape and aerostructural optimization are presented. To determine the flight conditions and their corresponding weights, a novel surrogate-based mission analysis is developed to efficiently analyze hundreds of actual mission data to emulate their flight condition distribution. Using accurate and reliable surrogate models to approximate the aerodynamic coefficients used in the analysis makes this procedure computationally tractable. A mixture of experts (ME) approach is developed to overcome the limitations of conventional surrogate models in modeling the complex transonic drag profile. The ME approach combines multiple surrogate models probabilistically based on the divide-andconquer strategy. Using this model in the mission analysis significantly improves the range estimation accuracy, as compared to other conventional surrogate models. As expected, the multipoint aerodynamic shape and aerostructural optimizations demonstrate a consistent drag reduction, instead of the localized improvement by the single-point optimizations. The improved robustness in the multipoint optimized designs was also observed in terms of the improved range performance and more consistent fuel-burn reduction across the different missions. The results presented in this thesis show that the surrogate-model-assisted multipoint optimization produces a robust

  9. "We Burn to Learn" About Fuel-Air Mixing Within Aircraft Powerplants

    NASA Technical Reports Server (NTRS)

    Robinson, Heidi N.

    2004-01-01

    I am working with my branch s advanced diagnostics team to investigate fuel-air mixing in jet-fueled gas turbine combustors and jet-fuel reformers. Our data acquisition begins with bench-top experiments which will help with calibration of equipment for facility testing. While conducting the bench-top experiments I learned to align laser and optical equipment to collect data, to use the data acquisition software, and to process the data into graphs and images. which jet he1 is to be reformed into hydrogen. Testing will commence shortly, after which we will obtain and analyze data and meet a critical milestone for the end of September. I am also designing the layout for a Schlieren system that will be used during that time frame. A Schlieren instrument records changes in the refractive index distribution of transparent media like air flows. The refractive index distribution can then be related to density, temperature, or pressure distributions within the flow. I am working on a scheme to quantify this information and add to the knowledge of the fuel-air mixing process.

  10. OPTIM: Computer program to generate a vertical profile which minimizes aircraft fuel burn or direct operating cost. User's guide

    NASA Technical Reports Server (NTRS)

    1983-01-01

    A profile of altitude, airspeed, and flight path angle as a function of range between a given set of origin and destination points for particular models of transport aircraft provided by NASA is generated. Inputs to the program include the vertical wind profile, the aircraft takeoff weight, the costs of time and fuel, certain constraint parameters and control flags. The profile can be near optimum in the sense of minimizing: (1) fuel, (2) time, or (3) a combination of fuel and time (direct operating cost (DOC)). The user can also, as an option, specify the length of time the flight is to span. The theory behind the technical details of this program is also presented.

  11. 14 CFR 33.79 - Fuel burning thrust augmentor.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Fuel burning thrust augmentor. 33.79 Section 33.79 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.79 Fuel...

  12. 14 CFR 33.79 - Fuel burning thrust augmentor.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel burning thrust augmentor. 33.79 Section 33.79 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.79 Fuel...

  13. Alternative aircraft fuels technology

    NASA Technical Reports Server (NTRS)

    Grobman, J.

    1976-01-01

    NASA is studying the characteristics of future aircraft fuels produced from either petroleum or nonpetroleum sources such as oil shale or coal. These future hydrocarbon based fuels may have chemical and physical properties that are different from present aviation turbine fuels. This research is aimed at determining what those characteristics may be, how present aircraft and engine components and materials would be affected by fuel specification changes, and what changes in both aircraft and engine design would be required to utilize these future fuels without sacrificing performance, reliability, or safety. This fuels technology program was organized to include both in-house and contract research on the synthesis and characterization of fuels, component evaluations of combustors, turbines, and fuel systems, and, eventually, full-scale engine demonstrations. A review of the various elements of the program and significant results obtained so far are presented.

  14. Alternative aircraft fuels

    NASA Technical Reports Server (NTRS)

    Longwell, J. P.; Grobman, J. S.

    1977-01-01

    The efficient utilization of fossil fuels by future jet aircraft may necessitate the broadening of current aviation turbine fuel specifications. The most significant changes in specifications would be an increased aromatics content and a higher final boiling point in order to minimize refinery energy consumption and costs. These changes would increase the freezing point and might lower the thermal stability of the fuel, and could cause increased pollutant emissions, increased combustor liner temperatures, and poorer ignition characteristics. The effects that broadened specification fuels may have on present-day jet aircraft and engine components and the technology required to use fuels with broadened specifications are discussed.

  15. Fuel Burn Estimation Using Real Track Data

    NASA Technical Reports Server (NTRS)

    Chatterji, Gano B.

    2011-01-01

    A procedure for estimating fuel burned based on actual flight track data, and drag and fuel-flow models is described. The procedure consists of estimating aircraft and wind states, lift, drag and thrust. Fuel-flow for jet aircraft is determined in terms of thrust, true airspeed and altitude as prescribed by the Base of Aircraft Data fuel-flow model. This paper provides a theoretical foundation for computing fuel-flow with most of the information derived from actual flight data. The procedure does not require an explicit model of thrust and calibrated airspeed/Mach profile which are typically needed for trajectory synthesis. To validate the fuel computation method, flight test data provided by the Federal Aviation Administration were processed. Results from this method show that fuel consumed can be estimated within 1% of the actual fuel consumed in the flight test. Next, fuel consumption was estimated with simplified lift and thrust models. Results show negligible difference with respect to the full model without simplifications. An iterative takeoff weight estimation procedure is described for estimating fuel consumption, when takeoff weight is unavailable, and for establishing fuel consumption uncertainty bounds. Finally, the suitability of using radar-based position information for fuel estimation is examined. It is shown that fuel usage could be estimated within 5.4% of the actual value using positions reported in the Airline Situation Display to Industry data with simplified models and iterative takeoff weight computation.

  16. Alternative aircraft fuels

    NASA Technical Reports Server (NTRS)

    Longwell, J. P.; Grobman, J.

    1978-01-01

    In connection with the anticipated impossibility to provide on a long-term basis liquid fuels derived from petroleum, an investigation has been conducted with the objective to assess the suitability of jet fuels made from oil shale and coal and to develop a data base which will allow optimization of future fuel characteristics, taking energy efficiency of manufacture and the tradeoffs in aircraft and engine design into account. The properties of future aviation fuels are examined and proposed solutions to problems of alternative fuels are discussed. Attention is given to the refining of jet fuel to current specifications, the control of fuel thermal stability, and combustor technology for use of broad specification fuels. The first solution is to continue to develop the necessary technology at the refinery to produce specification jet fuels regardless of the crude source.

  17. Burning Fuel Droplet

    NASA Technical Reports Server (NTRS)

    2003-01-01

    Fuel ignites and burns in the Droplet Combustion Experiment (DCE) on STS-94 on July 4 1997, MET:2/05:40 (approximate). The DCE was designed to investigate the fundamental combustion aspects of single, isolated droplets under different pressures and ambient oxygen concentrations for a range of droplet sizes varying between 2 and 5 mm. DCE used various fuels -- in drops ranging from 1 mm (0.04 inches) to 5 mm (0.2 inches) -- and mixtures of oxidizers and inert gases to learn more about the physics of combustion in the simplest burning configuration, a sphere. The experiment elapsed time is shown at the bottom of the composite image. The DCE principal investigator was Forman Williams, University of California, San Diego. The experiment was part of the space research investigations conducted during the Microgravity Science Laboratory-1R mission (STS-94, July 1-17 1997). Advanced combustion experiments will be a part of investigations plarned for the International Space Station. (121KB JPEG, 654 x 977 pixels; downlinked video, higher quality not available) The MPG from which this composite was made is available at http://mix.msfc.nasa.gov/ABSTRACTS/MSFC-0300169.html.

  18. Jet aircraft hydrocarbon fuels technology

    NASA Technical Reports Server (NTRS)

    Longwell, J. P. (Editor)

    1978-01-01

    A broad specification, referee fuel was proposed for research and development. This fuel has a lower, closely specified hydrogen content and higher final boiling point and freezing point than ASTM Jet A. The workshop recommended various priority items for fuel research and development. Key items include prediction of tradeoffs among fuel refining, distribution, and aircraft operating costs; combustor liner temperature and emissions studies; and practical simulator investigations of the effect of high freezing point and low thermal stability fuels on aircraft fuel systems.

  19. Fuel Burn Estimation Model

    NASA Technical Reports Server (NTRS)

    Chatterji, Gano

    2011-01-01

    Conclusions: Validated the fuel estimation procedure using flight test data. A good fuel model can be created if weight and fuel data are available. Error in assumed takeoff weight results in similar amount of error in the fuel estimate. Fuel estimation error bounds can be determined.

  20. Aircraft Fuel Systems Career Ladder.

    DTIC Science & Technology

    1985-09-01

    type fittings remove and install fuel cells clean work areas inspect aircraft for safety pin installation purge tanks or cells using blow purge method...INSPECT AIRCRAFT FOR SAFETY PIN INSTALLATION 84 H254 PURGE TANKS OR CELLS USING BLOW PURGE METHOD 83 H227 CHECK AIRCRAFT FOR LIQUID OXYGEN (LOX...H243 INSPECT AIRCRAFT FOR SAFETY PIN INSTALLATION 52 M483 MIX SEALANTS BY HAND 48 K372 CONNECT OR DISCONNECT WIGGINS TYPE FITTINGS 48 H236 DISCONNECT

  1. Fuel conservative aircraft engine technology

    NASA Technical Reports Server (NTRS)

    Nored, D. L.

    1978-01-01

    Technology developments for more fuel-efficiency subsonic transport aircraft are reported. Three major propulsion projects were considered: (1) engine component improvement - directed at current engines; (2) energy efficient engine - directed at new turbofan engines; and (3) advanced turboprops - directed at technology for advanced turboprop-powered aircraft. Each project is reviewed and some of the technologies and recent accomplishments are described.

  2. Aircraft Fuel Cell Power Systems

    NASA Technical Reports Server (NTRS)

    Needham, Robert

    2004-01-01

    In recent years, fuel cells have been explored for use in aircraft. While the weight and size of fuel cells allows only the smallest of aircraft to use fuel cells for their primary engines, fuel cells have showed promise for use as auxiliary power units (APUs), which power aircraft accessories and serve as an electrical backup in case of an engine failure. Fuel cell MUS are both more efficient and emit fewer pollutants. However, sea-level fuel cells need modifications to be properly used in aircraft applications. At high altitudes, the ambient air has a much lower pressure than at sea level, which makes it much more difficult to get air into the fuel cell to react and produce electricity. Compressors can be used to pressurize the air, but this leads to added weight, volume, and power usage, all of which are undesirable things. Another problem is that fuel cells require hydrogen to create electricity, and ever since the Hindenburg burst into flames, aircraft carrying large quantities of hydrogen have not been in high demand. However, jet fuel is a hydrocarbon, so it is possible to reform it into hydrogen. Since jet fuel is already used to power conventional APUs, it is very convenient to use this to generate the hydrogen for fuel-cell-based APUs. Fuel cells also tend to get large and heavy when used for applications that require a large amount of power. Reducing the size and weight becomes especially beneficial when it comes to fuel cells for aircraft. My goal this summer is to work on several aspects of Aircraft Fuel Cell Power System project. My first goal is to perform checks on a newly built injector rig designed to test different catalysts to determine the best setup for reforming Jet-A fuel into hydrogen. These checks include testing various thermocouples, transmitters, and transducers, as well making sure that the rig was actually built to the design specifications. These checks will help to ensure that the rig will operate properly and give correct results

  3. Assessment of Alternative Aircraft Fuels

    NASA Technical Reports Server (NTRS)

    1984-01-01

    The purpose of this symposium is to provide representatives from industry, government, and academia concerned with the availability and quality of future aviation turbine fuels with recent technical results and a status review of DOD and NASA sponsored fuels research projects. The symposium has included presentations on the potential crude sources, refining methods, and characteristics of future fuels; the effects of changing fuel characteristics on the performance and durability of jet aircraft components and systems; and the prospects for evolving suitable technology to produce and use future fuels.

  4. Alternate-fueled transport aircraft possibilities

    NASA Technical Reports Server (NTRS)

    Aiken, W. S.

    1977-01-01

    The paper is organized to describe: (1) NASA's cryogenically fueled aircraft program; (2) LH2 subsonic and supersonic transport design possibilities (3) the fuel system and ground side problems associated with LH2 distribution; (4) a comparison of LCH4 with LH2; (5) the design possibilities for LCH4 fueled aircraft; and (6) a summary of where NASA's cryogenically fueled programs are headed.

  5. Alternate Fuels for Use in Commercial Aircraft

    NASA Technical Reports Server (NTRS)

    Daggett, David L.; Hendricks, Robert C.; Walther, Rainer; Corporan, Edwin

    2008-01-01

    The engine and aircraft Research and Development (R&D) communities have been investigating alternative fueling in near-term, midterm, and far-term aircraft. A drop in jet fuel replacement, consisting of a kerosene (Jet-A) and synthetic fuel blend, will be possible for use in existing and near-term aircraft. Future midterm aircraft may use a biojet and synthetic fuel blend in ultra-efficient airplane designs. Future far-term engines and aircraft in 50-plus years may be specifically designed to use a low- or zero-carbon fuel. Synthetic jet fuels from coal, natural gas, or other hydrocarbon feedstocks are very similar in performance to conventional jet fuel, yet the additional CO2 produced during the manufacturing needs to be permanently sequestered. Biojet fuels need to be developed specifically for jet aircraft without displacing food production. Envisioned as midterm aircraft fuel, if the performance and cost liabilities can be overcome, biofuel blends with synthetic jet or Jet-A fuels have near-term potential in terms of global climatic concerns. Long-term solutions address dramatic emissions reductions through use of alternate aircraft fuels such as liquid hydrogen or liquid methane. Either of these new aircraft fuels will require an enormous change in infrastructure and thus engine and airplane design. Life-cycle environmental questions need to be addressed.

  6. Potential release of fibers from burning carbon composites. [aircraft fires

    NASA Technical Reports Server (NTRS)

    Bell, V. L.

    1980-01-01

    A comprehensive experimental carbon fiber source program was conducted to determine the potential for the release of conductive carbon fibers from burning composites. Laboratory testing determined the relative importance of several parameters influencing the amounts of single fibers released, while large-scale aviation jet fuel pool fires provided realistic confirmation of the laboratory data. The dimensions and size distributions of fire-released carbon fibers were determined, not only for those of concern in an electrical sense, but also for those of potential interest from a health and environmental standpoint. Fire plume and chemistry studies were performed with large pool fires to provide an experimental input into an analytical modelling of simulated aircraft crash fires. A study of a high voltage spark system resulted in a promising device for the detection, counting, and sizing of electrically conductive fibers, for both active and passive modes of operation.

  7. Study of Hydrogen As An Aircraft Fuel

    DTIC Science & Technology

    2003-06-01

    8 4 F. AMMONIA ............................................9 G . FUEL-CANDIDATE SUMMARY ............................11...would be up to 2.5 times as much as with conventional aircraft fuel, leading to vehicles of enormous size and limited capability.11 G . FUEL-CANDIDATE...Density Hydrogen Storage.” <http://www.apolloenergysystems.com/HighDensity_STOR.h tm>, January 16, 2003. Brewer, G . Daniel. Hydrogen Aircraft

  8. Investigation of critical burning of fuel droplets

    NASA Technical Reports Server (NTRS)

    Allison, C. B.; Canada, G. S.; Faeth, G. M.

    1972-01-01

    Measurements were made on the burning of liquid hydrazine, MMH, and UDMH in a combustion gas environment. The experimental range of these tests involved gas temperatures of 1660-2530 K, oxygen concentrations of 0-42% by mass and droplet diameters (employing both droplets and porous spheres) of 0.11-1.91 cm. at atmospheric pressure. A simplified hybrid combustion theory was developed which was found to correlate the present results as well as the experimental measurements of other investigators. Measurements were also made of the monopropellant strand burning rates and liquid surface temperatures of a number of nitrate ester fuels and hydrazine at elevated pressures. The temperature measurements for the nitrate esters were found to be in good agreement with a theoretical model which allowed for gas solubility in the liquid phase at high pressures. Experimental results were also obtained on the burning rates and liquid surface temperatures of a number of paraffin and alcohol fuels burning in air pressures up to 72 atm. For these tests, the fuels were burned from porous spheres in a natural convection environment. Initial findings on a pressurized flat flame burner are also described as well as the design of an oscillatory combustion apparatus to test the response of burning liquid fuels.

  9. Fuel characteristics pertinent to the design of aircraft fuel systems

    NASA Technical Reports Server (NTRS)

    Barnett, Henry C; Hibbard, R R

    1953-01-01

    Because of the importance of fuel properties in design of aircraft fuel systems the present report has been prepared to provide information on the characteristics of current jet fuels. In addition to information on fuel properties, discussions are presented on fuel specifications, the variations among fuels supplied under a given specification, fuel composition, and the pertinence of fuel composition and physical properties to fuel system design. In some instances the influence of variables such as pressure and temperature on physical properties is indicated. References are cited to provide fuel system designers with sources of information containing more detail than is practicable in the present report.

  10. Some aspects of aircraft jet engine fuels

    NASA Technical Reports Server (NTRS)

    Bekiesinski, R.

    1979-01-01

    Technologies are reviewed for improving the thermal stability of jet fuels, with reference to the overheating of fuel tanks in supersonic aircraft. Consideration is given to the development of a jet fuel with high thermal stability by the Polish petroleum industry.

  11. Modeling Deep Burn TRISO particle nuclear fuel

    NASA Astrophysics Data System (ADS)

    Besmann, T. M.; Stoller, R. E.; Samolyuk, G.; Schuck, P. C.; Golubov, S. I.; Rudin, S. P.; Wills, J. M.; Coe, J. D.; Wirth, B. D.; Kim, S.; Morgan, D. D.; Szlufarska, I.

    2012-11-01

    Under the DOE Deep Burn program TRISO fuel is being investigated as a fuel form for consuming plutonium and minor actinides, and for greater efficiency in uranium utilization. The result will thus be to drive TRISO particulate fuel to very high burn-ups. In the current effort the various phenomena in the TRISO particle are being modeled using a variety of techniques. The chemical behavior is being treated utilizing thermochemical analysis to identify phase formation/transformation and chemical activities in the particle, including kernel migration. Density functional theory is being used to understand fission product diffusion within the plutonia oxide kernel, the fission product's attack on the SiC coating layer, as well as fission product diffusion through an alternative coating layer, ZrC. Finally, a multiscale approach is being used to understand thermal transport, including the effect of radiation damage induced defects, in a model SiC material.

  12. Initial fuel temperature effects on burning rate of pool fire.

    PubMed

    Chen, Bing; Lu, Shou-Xiang; Li, Chang-Hai; Kang, Quan-Sheng; Lecoustre, Vivien

    2011-04-15

    The influence of the initial fuel temperature on the burning behavior of n-heptane pool fire was experimentally studied at the State Key Laboratory of Fire Science (SKLFS) large test hall. Circular pool fires with diameters of 100mm, 141 mm, and 200 mm were considered with initial fuel temperatures ranging from 290 K to 363 K. Burning rate and temperature distributions in fuel and vessel wall were recorded during the combustion. The burning rate exhibited five typical stages: initial development, steady burning, transition, bulk boiling burning, and decay. The burning rate during the steady burning stage was observed to be relatively independent of the initial fuel temperature. In contrast, the burning rate of the bulk boiling burning stage increases with increased initial fuel temperature. It was also observed that increased initial fuel temperature decreases the duration of steady burning stage. When the initial temperature approaches the boiling point, the steady burning stage nearly disappears and the burning rate moves directly from the initial development stage to the transition stage. The fuel surface temperature increases to its boiling point at the steady burning stage, shortly after ignition, and the bulk liquid reaches boiling temperature at the bulk boiling burning stage. No distinguished cold zone is formed in the fuel bed. However, boiling zone is observed and the thickness increases to its maximum value when the bulk boiling phenomena occurs.

  13. Commercial aircraft fuel efficiency potential through 2010

    SciTech Connect

    Greene, D.L.

    1990-01-01

    Aircraft are second only to motor vehicles in the use of motor fuels, and air travel is growing twice as fast. Since 1970 air travel has more than tripled, but the growth of fuel use has been restrained by a near doubling of efficiency, from 26.2 seat miles per gallon (SMPG) in 1970 to about 49 SMPG in 1989. This paper explores the potential for future efficiency improvements via the replacement of existing aircraft with 1990's generation'' and post 2000'' aircraft incorporating advances in engine and airframe technology. Today, new commercial passenger aircraft deliver 50--70 SMPG. New aircraft types scheduled for delivery in the early 1990's are expected to achieve 65--80 SMPG. Industry and government researchers have identified technologies capable of boosting aircraft efficiencies to the 100--150 SMPG range. Under current industry plans, which do not include a post-2000 generation of new aircraft, the total aircraft fleet should reach the vicinity of 65 SMPG by 2010. A new generation of 100--150 SMPG aircraft introduced in 2005 could raise the fleet average efficiency to 75--80 SMPG in 2010. In any case, fuel use will likely continue to grow at from 1--2%/yr. through 2010. 20 refs., 2 figs., 2 tabs.

  14. Alternate aircraft fuels: Prospects and operational implications

    NASA Technical Reports Server (NTRS)

    Witcofski, R. D.

    1977-01-01

    The potential use of coal-derived aviation fuels was assessed. The studies addressed the prices and thermal efficiencies associated with the production of coal-derived aviation kerosene, liquid methane and liquid hydrogen and the air terminal requirements and subsonic transport performance when utilizing liquid hydrogen. The fuel production studies indicated that liquid methane can be produced at a lower price and with a higher thermal efficiency than aviation kerosene or liquid hydrogen. Ground facilities of liquefaction, storage, distribution and refueling of liquid hydrogen fueled aircraft at airports appear technically feasibile. The aircraft studies indicate modest onboard energy savings for hydrogen compared to conventional fuels. Liquid hydrogen was found to be superior to both aviation kerosene and liquid methane from the standpoint of aircraft engine emissions.

  15. Fuel Droplet Burning During Droplet Combustion Experiment

    NASA Technical Reports Server (NTRS)

    2003-01-01

    Fuel ignites and burns in the Droplet Combustion Experiment (DCE) on STS-94 on July 4 1997, MET:2/05:40 (approximate). The DCE was designed to investigate the fundamental combustion aspects of single, isolated droplets under different pressures and ambient oxygen concentrations for a range of droplet sizes varying between 2 and 5 mm. DCE used various fuels -- in drops ranging from 1 mm (0.04 inches) to 5 mm (0.2 inches) -- and mixtures of oxidizers and inert gases to learn more about the physics of combustion in the simplest burning configuration, a sphere. The experiment elapsed time is shown at the bottom of the composite image. The DCE principal investigator was Forman Williams, University of California, San Diego. The experiment was part of the space research investigations conducted during the Microgravity Science Laboratory-1R mission (STS-94, July 1-17 1997). Advanced combustion experiments will be a part of investigations plarned for the International Space Station. (1.4MB, 13-second MPEG, screen 320 x 240 pixels; downlinked video, higher quality not available)A still JPG composite of this movie is available at http://mix.msfc.nasa.gov/ABSTRACTS/MSFC-0300168.html.

  16. Transient burning of a convective fuel droplet

    SciTech Connect

    Wu, Guang; Sirignano, William A.

    2010-05-15

    The transient burning of an n-octane fuel droplet in a hot gas stream at 20 atmosphere pressure is numerically studied, with considerations of droplet regression, deceleration due to the drag of the droplet, internal circulation inside the droplet, variable properties, non-uniform surface temperature, and the effect of surface tension. An initial envelope flame is found to remain envelope in time, and an initial wake flame is always transitioned into an envelope flame at a later time, with the normalized transition delay controlled by the initial Reynolds number and the initial Damkohler number. The initial flame shape is primarily determined by the initial Damkohler number, which has a critical value of Da{sub 0}=1.02. The burning rates are modified by the transition, and are influenced by the intensity of forced convection which is determined by initial Reynolds number. The influence of surface tension is also studied as the surface temperature is non-uniform. Surface tension affects the liquid motion at the droplet surface significantly and affects the change of surface temperature and burning rate modestly. The influence of surface tension generally increases with increasing initial Reynolds number within the range without droplet breakup. We also studied cases with constant relative velocity between the air stream and the droplet. The results show that in these cases the initial envelope flame still remains envelope, but the evolution from an initial wake flame to an envelope flame is inhibited. Validation of our analysis is made by comparing with a published porous-sphere experiment Raghavan et al. (2005) which used methanol fuel. (author)

  17. 19 CFR 10.62b - Aircraft turbine fuel.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 19 Customs Duties 1 2011-04-01 2011-04-01 false Aircraft turbine fuel. 10.62b Section 10.62b... Supplies and Equipment for Vessels § 10.62b Aircraft turbine fuel. (a) General. Unless otherwise provided, aircraft turbine fuel withdrawn from a Customs bonded warehouse for use under section 309, Tariff Act...

  18. 19 CFR 10.62b - Aircraft turbine fuel.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 19 Customs Duties 1 2013-04-01 2013-04-01 false Aircraft turbine fuel. 10.62b Section 10.62b... Supplies and Equipment for Vessels § 10.62b Aircraft turbine fuel. (a) General. Unless otherwise provided, aircraft turbine fuel withdrawn from a Customs bonded warehouse for use under section 309, Tariff Act...

  19. 19 CFR 10.62b - Aircraft turbine fuel.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 19 Customs Duties 1 2012-04-01 2012-04-01 false Aircraft turbine fuel. 10.62b Section 10.62b... Supplies and Equipment for Vessels § 10.62b Aircraft turbine fuel. (a) General. Unless otherwise provided, aircraft turbine fuel withdrawn from a Customs bonded warehouse for use under section 309, Tariff Act...

  20. 19 CFR 10.62b - Aircraft turbine fuel.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 19 Customs Duties 1 2014-04-01 2014-04-01 false Aircraft turbine fuel. 10.62b Section 10.62b... Supplies and Equipment for Vessels § 10.62b Aircraft turbine fuel. (a) General. Unless otherwise provided, aircraft turbine fuel withdrawn from a Customs bonded warehouse for use under section 309, Tariff Act...

  1. Fuel Cell Airframe Integration Study for Short-Range Aircraft. Volume 1; Aircraft Propulsion and Subsystems Integration Evaluation

    NASA Technical Reports Server (NTRS)

    Gummalla, Mallika; Pandy, Arun; Braun, Robert; Carriere, Thierry; Yamanis, Jean; Vanderspurt, Thomas; Hardin, Larry; Welch, Rick

    2006-01-01

    The objective of this study is to define the functionality and evaluate the propulsion and power system benefits derived from a Solid Oxide Fuel Cell (SOFC) based Auxiliary Power Unit (APU) for a future short range commercial aircraft, and to define the technology gaps to enable such a system. United Technologies Corporation (UTC) Integrated Total Aircraft Power System (ITAPS) methodologies were used to evaluate a baseline aircraft and several SOFC architectures. The technology benefits were captured as reductions of the mission fuel burn, life cycle cost, noise and emissions. As a result of the study, it was recognized that system integration is critical to maximize benefits from the SOFC APU for aircraft application. The mission fuel burn savings for the two SOFC architectures ranged from 4.7 percent for a system with high integration to 6.7 percent for a highly integrated system with certain technological risks. The SOFC APU itself produced zero emissions. The reduction in engine fuel burn achieved with the SOFC systems also resulted in reduced emissions from the engines for both ground operations and in flight. The noise level of the baseline APU with a silencer is 78 dBA, while the SOFC APU produced a lower noise level. It is concluded that a high specific power SOFC system is needed to achieve the benefits identified in this study. Additional areas requiring further development are the processing of the fuel to remove sulfur, either on board or on the ground, and extending the heat sink capability of the fuel to allow greater waste heat recovery, resolve the transient electrical system integration issues, and identification of the impact of the location of the SOFC and its size on the aircraft.

  2. Fuels and Lubricants for Aircraft

    DTIC Science & Technology

    1975-02-27

    OcLa- sionally, the monopropellant used is a substance that does not burn, but de- composes with the evolution of heat (for example, hydrogen peroxide ...349. Oxygen-containing inorganic compounds (nitric acid and nitrogen tetroxide, hydrogen peroxide , etc.) 30. Liquid fluorine and its compounds (oxygen...studyin7,. the chain prco.esses of formnation and decomposition of gaseous inter- mediate products ( peroxides , aldehydes, etc.) at relativel~y low

  3. Jet aircraft fuel system deposits

    SciTech Connect

    Hazlett, R.N.; Hall, J.M.

    1981-03-01

    Deposits samples were from the valve cavity of a fuel nozzle of a CF6-50A engine, from the fuel manifold adjacent to the combustor nozzles of a TR-30 engine, fuel test devices, and heat exchange tubes, operated in the laboratories of the Naval Air Propulsion Center and the Air Force Aero Propulsion Laboratory. Carbon, hydrogen, nitrogen and oxygen in the deposits were determined with a Perkin Elmer Elemental Analyzer. Sulfur was determined on a separate sample by modifying ASTM method D3120-75. The high amount of oxygen, nitrogen and sulfur found in the deposits is noteworthy. The data reported generally corroborates the information from the literature. All of the deposits from the engines and the test devices point to the importance of compounds containing hereto atoms. The importance of oxidation in triggering solids formation has been reviewed. It would appear that the trace primary oxidation reactions occurring in a fuel system would be insufficient to give the high concentration of oxygen in the deposit. However, if the compounds undergoing oxidation were oxygen-containing compounds rather than hydrocarbons the high oxygen concentrations in the deposit would be more reasonable. The high enhancement factors observed, causes one to conclude that some nitrogen and sulfur compounds found in fuels are very susceptible to oxidation and subsequent deposit formation. The high concentrations of hereto atoms implies that the deposits have highly polar characteristics. Since such material would have little attraction for the non-polar fuel, the insolubility of deposits may be due primarily to polarity differences rather than high molecular weight.

  4. Economic study of future aircraft fuels (1970-2000)

    NASA Technical Reports Server (NTRS)

    Alexander, A. D., III

    1972-01-01

    Future aircraft fuels are evaluated in terms of fuel resource availability and pricing, processing methods, and economic projections over the period 1970-2000. Liquefied hydrogen, methane and propane are examined as potential turbine engine aircraft fuels relative to current JP fuel.

  5. Aircraft Fuel Tank Inerting System

    DTIC Science & Technology

    1983-07-01

    replacement of materials lost In eiactrostatically induced fuel tank fires for systems that use blue foam. During the program, funding cuts eliminated the...with a diameter of 40 microns and a 6-micron wall thickness. The structure of the polymethylpentene material permits the oxygen to permeate through the...auxiliary studies and manufacture of permeable membrane modules, which were subcontracted as follows: Boeing Aerospace Company, Wichita , Ka., for

  6. Development and experimental characterization of a fuel cell powered aircraft

    NASA Astrophysics Data System (ADS)

    Bradley, Thomas H.; Moffitt, Blake A.; Mavris, Dimitri N.; Parekh, David E.

    This paper describes the characteristics and performance of a fuel cell powered unmanned aircraft. The aircraft is novel as it is the largest compressed hydrogen fuel cell powered airplane built to date and is currently the only fuel cell aircraft whose design and test results are in the public domain. The aircraft features a 500 W polymer electrolyte membrane fuel cell with full balance of plant and compressed hydrogen storage incorporated into a custom airframe. Details regarding the design requirements, implementation and control of the aircraft are presented for each major aircraft system. The performances of the aircraft and powerplant are analyzed using data from flights and laboratory tests. The efficiency and component power consumption of the fuel cell propulsion system are measured at a variety of flight conditions. The performance of the aircraft powerplant is compared to other 0.5-1 kW-scale fuel cell powerplants in the literature and means of performance improvement for this aircraft are proposed. This work represents one of the first studies of fuel cell powered aircraft to result in a demonstration aircraft. As such, the results of this study are of practical interest to fuel cell powerplant and aircraft designers.

  7. Noise and Fuel Burn Reduction Potential of an Innovative Subsonic Transport Configuration

    NASA Technical Reports Server (NTRS)

    Guo, Yueping; Nickol, Craig L.; Thomas, Russell H.

    2014-01-01

    A study is presented for the noise and fuel burn reduction potential of an innovative double deck concept aircraft with two three-shaft direct-drive turbofan engines. The engines are mounted from the fuselage so that the engine inlet is over the main wing. It is shown that such an aircraft can achieve a cumulative Effective Perceived Noise Level (EPNL) about 28 dB below the current aircraft noise regulations of Stage 4. The combination of high bypass ratio engines and advanced wing design with laminar flow control technologies provide fuel burn reduction and low noise levels simultaneously. For example, the fuselage mounted engine position provides more than 4 EPNLdB of noise reduction by shielding the inlet radiated noise. To identify the potential effect of noise reduction technologies on this concept, parametric studies are presented to reveal the system level benefits of various emerging noise reduction concepts, for both engine and airframe noise reduction. These concepts are discussed both individually to show their respective incremental noise reduction potential and collectively to assess their aggregate effects on the total noise. Through these concepts approximately about 8 dB of additional noise reduction is possible, bringing the cumulative noise level of this aircraft to 36 EPNLdB below Stage 4, if the entire suite of noise reduction technologies would mature to practical application. In a final step, an estimate is made for this same aircraft concept but with higher bypass ratio, geared, turbofan engines. With this geared turbofan propulsion system, the noise is estimated to reach as low as 40-42 dB below Stage 4 with a fuel burn reduction of 43-47% below the 2005 best-in-class aircraft baseline. While just short of the NASA N+2 goals of 42 dB and 50% fuel burn reduction, for a 2025 in service timeframe, this assessment shows that this innovative concept warrants refined study. Furthermore, this design appears to be a viable potential future passenger

  8. Sizing of an aircraft fuel pump

    SciTech Connect

    Rohatgi, U.S.

    1995-06-01

    A need to pump a mixture of two-phase fluid appears naturally in many situations. One example of this situation is aircraft fuel systems, where the pump inlet may have two-phase mixture due to the desorption of the dissolved gases at low pressures at higher altitudes. A simple procedure of selecting proper design conditions for the inlet inducer and a method of sizing the inducer, impeller and volute to meet all the design requirements has been described. This procedure has also been applied to a typical fighter plane boost pump design.

  9. Sources of black carbon in aerosols: fossil fuel burning vs. biomass burning

    NASA Astrophysics Data System (ADS)

    Hsieh, Y.

    2013-12-01

    The uncertainty in black carbon (BC) analysis and our inability to directly quantify the BC sources in the atmosphere has led to the uncertainty in compiling a regional or global BC emission inventory attributed to biomass burnings. We initiate this study to demonstrate a new approach, which quantifies the source of BC in the atmosphere between biomass and fossil fuel burnings. We applied the newly developed multi-element scanning thermal analysis (MESTA) technology to quantify BC and organic carbon (OC), respectively, in aerosol samples. MESTA can also separate BC from OC for subsequent radiocarbon analyses. Because fossil fuel has been depleted of radiocarbon and biomass has radiocarbon of the modern atmospheric level, we can quantify the sources of BC between fossil fuel and biomass burnings. We sampled the PM2.5 in the ambient air of central Tallahassee and its rural areas during the May-June (prescribed burning) and Nov-Dec (non-burning) periods. The results indicate that biomass burning contributed 89×1% and 67×2% of BC, respectively, during May-June and Nov.-Dec. periods. The rest of PM2.5 BC was contributed from fossil fuel burning. The radiocarbon contents of the OC was 103.42×0.55 percent modern carbon (pmC), which is consistent with the current atmospheric level with a trace of the bomb radiocarbon remained from the open atmosphere nuclear testing.

  10. Commercial Aircraft Airframe Fuel Systems Survey and Analysis.

    DTIC Science & Technology

    1982-02-01

    Fairchild Swearingen Corporation Pratt & Whitney Aircraft of Canada Ltd. P.O. Box 894 Box 10 San Antonio, Texas 78284 Longueuil , Quebec J4K 4X9 Mr...Antimisting Fuel Engineering and Development Plan, FAA-ED-18-4. The objective was to study the fuel systems of a representative sample of commercial aircraft

  11. Characteristics and combustion of future hydrocarbon fuels. [aircraft fuels

    NASA Technical Reports Server (NTRS)

    Rudey, R. A.; Grobman, J. S.

    1978-01-01

    As the world supply of petroleum crude oil is being depleted, the supply of high-quality crude oil is also dwindling. This dwindling supply is beginning to manifest itself in the form of crude oils containing higher percentages of aromatic compounds, sulphur, nitrogen, and trace constituents. The result of this trend is described and the change in important crude oil characteristics, as related to aircraft fuels, is discussed. As available petroleum is further depleted, the use of synthetic crude oils (those derived from coal and oil shale) may be required. The principal properties of these syncrudes and the fuels that can be derived from them are described. In addition to the changes in the supply of crude oil, increasing competition for middle-distillate fuels may require that specifications be broadened in future fuels. The impact that the resultant potential changes in fuel properties may have on combustion and thermal stability characteristics is illustrated and discussed in terms of ignition, soot formation, carbon deposition flame radiation, and emissions.

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

    NASA Technical Reports Server (NTRS)

    Berry, W.; Calleson, R.; Espil, J.; Quartero, C.; Swanson, E.

    1972-01-01

    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.

  13. Experimental Study of Turbine Fuel Thermal Stability in an Aircraft Fuel System Simulator

    NASA Technical Reports Server (NTRS)

    Vranos, A.; Marteney, P. J.

    1980-01-01

    The thermal stability of aircraft gas turbines fuels was investigated. The objectives were: (1) to design and build an aircraft fuel system simulator; (2) to establish criteria for quantitative assessment of fuel thermal degradation; and (3) to measure the thermal degradation of Jet A and an alternative fuel. Accordingly, an aircraft fuel system simulator was built and the coking tendencies of Jet A and a model alternative fuel (No. 2 heating oil) were measured over a range of temperatures, pressures, flows, and fuel inlet conditions.

  14. Burned in: Fueling the Fire to Teach

    ERIC Educational Resources Information Center

    Friedman, Audrey A.; Reynolds, Luke

    2011-01-01

    Almost half of new teachers leave the profession within their first year. New teachers need support, mentoring, encouragement, and, most importantly, hope in order to survive the challenges of their first years of teaching. "Burned In" features essays from today's most visionary educators, including Jim Burke, Peter Elbow, James Loewen, Gregory…

  15. TRIGA Mark II Criticality Benchmark Experiment with Burned Fuel

    SciTech Connect

    Persic, Andreja; Ravnik, Matjaz; Zagar, Tomaz

    2000-12-15

    The experimental results of criticality benchmark experiments performed at the Jozef Stefan Institute TRIGA Mark II reactor are presented. The experiments were performed with partly burned fuel in two compact and uniform core configurations in the same arrangements as were used in the fresh fuel criticality benchmark experiment performed in 1991. In the experiments, both core configurations contained only 12 wt% U-ZrH fuel with 20% enriched uranium. The first experimental core contained 43 fuel elements with average burnup of 1.22 MWd or 2.8% {sup 235}U burned. The last experimental core configuration was composed of 48 fuel elements with average burnup of 1.15 MWd or 2.6% {sup 235}U burned. The experimental determination of k{sub eff} for both core configurations, one subcritical and one critical, are presented. Burnup for all fuel elements was calculated in two-dimensional four-group diffusion approximation using the TRIGLAV code. The burnup of several fuel elements was measured also by the reactivity method.

  16. Investigation of critical burning of fuel droplets

    NASA Technical Reports Server (NTRS)

    Faeth, G. M.

    1979-01-01

    The general problem of spray combustion was investigated. The combustion of bipropellent droplets; combustion of hydrozine fuels; and combustion of sprays were studied. A model was developed to predict mean velocities and temperatures in a combusting gas jet.

  17. Environmentally Responsible Aviation: Propulsion Research to Enable Fuel Burn, Noise and Emissions Reduction

    NASA Technical Reports Server (NTRS)

    Van Zante, Dale E.; Suder, Kenneth L.

    2015-01-01

    The NASA Environmentally Responsible Aviation (ERA) program is maturing technologies to enable simultaneous reduction of fuel burn, noise and emissions from an aircraft engine system. Three engine related Integrated Technology Demonstrations (ITDs) have been completed at Glenn Research Center in collaboration with Pratt Whitney, General Electric and the Federal Aviation Administration. The engine technologies being matured are a low NOx, fuel flexible combustor in partnership with Pratt Whitney, an ultra-high bypass, ducted propulsor system in partnership with Pratt Whitney FAA and high pressure ratio, front-stage core compressor technology in partnership with General Electric. The technical rationale, test configurations and overall results from the test series in each ITD are described. ERA is using system analysis to project the benefits of the ITD technologies on potential aircraft systems in the 2025 timeframe. Data from the ITD experiments were used to guide the system analysis assumptions. Results from the current assessments for fuel burn, noise and oxides of nitrogen emissions are presented.

  18. Environmentally Responsible Aviation: Propulsion Research to Enable Fuel Burn, Noise and Emissions Reduction

    NASA Technical Reports Server (NTRS)

    Van Zante, Dale; Suder, Kenneth

    2015-01-01

    The NASA Environmentally Responsible Aviation (ERA) program is maturing technologies to enable simultaneous reduction of fuel burn, noise and emissions from an aircraft engine system. Three engine related Integrated Technology Demonstrations (ITDs) have been completed at Glenn Research Center in collaboration with Pratt Whitney, General Electric and the Federal Aviation Administration. The engine technologies being matured are: a low NOx, fuel flexible combustor in partnership with Pratt Whitney; an ultra-high bypass, ducted propulsor system in partnership with Pratt Whitney and FAA; and high pressure ratio, front-stage core compressor technology in partnership with General Electric. The technical rationale, test configurations and overall results from the test series in each ITD are described. ERA is using system analysis to project the benefits of the ITD technologies on potential aircraft systems in the 2025 timeframe. Data from the ITD experiments were used to guide the system analysis assumptions. Results from the current assessments for fuel burn, noise and oxides of nitrogen emissions are presented.

  19. 40 CFR 52.280 - Fuel burning equipment.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 17, 1981. (1) South Coast Air Quality Management District. (i) Rules 67, Fuel Burning Equipment, and... interfere with the attainment and maintenance of the National Ambient Air Quality Standards. (1) Mountain... attainment and maintenance of the national ambient air quality standards has not been submitted:...

  20. 40 CFR 52.280 - Fuel burning equipment.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 17, 1981. (1) South Coast Air Quality Management District. (i) Rules 67, Fuel Burning Equipment, and... interfere with the attainment and maintenance of the National Ambient Air Quality Standards. (1) Mountain... attainment and maintenance of the national ambient air quality standards has not been submitted:...

  1. 40 CFR 52.280 - Fuel burning equipment.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 17, 1981. (1) South Coast Air Quality Management District. (i) Rules 67, Fuel Burning Equipment, and... interfere with the attainment and maintenance of the National Ambient Air Quality Standards. (1) Mountain... attainment and maintenance of the national ambient air quality standards has not been submitted:...

  2. 40 CFR 52.280 - Fuel burning equipment.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 17, 1981. (1) South Coast Air Quality Management District. (i) Rules 67, Fuel Burning Equipment, and... interfere with the attainment and maintenance of the National Ambient Air Quality Standards. (1) Mountain... attainment and maintenance of the national ambient air quality standards has not been submitted:...

  3. 40 CFR 52.280 - Fuel burning equipment.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 17, 1981. (1) South Coast Air Quality Management District. (i) Rules 67, Fuel Burning Equipment, and... interfere with the attainment and maintenance of the National Ambient Air Quality Standards. (1) Mountain... attainment and maintenance of the national ambient air quality standards has not been submitted:...

  4. Fuel injection staged sectoral combustor for burning low-BTU fuel gas

    DOEpatents

    Vogt, Robert L.

    1985-02-12

    A high-temperature combustor for burning low-BTU coal gas in a gas turbine is described. The combustor comprises a plurality of individual combustor chambers. Each combustor chamber has a main burning zone and a pilot burning zone. A pipe for the low-BTU coal gas is connected to the upstream end of the pilot burning zone: this pipe surrounds a liquid fuel source and is in turn surrounded by an air supply pipe: swirling means are provided between the liquid fuel source and the coal gas pipe and between the gas pipe and the air pipe. Additional preheated air is provided by counter-current coolant air in passages formed by a double wall arrangement of the walls of the main burning zone communicating with passages of a double wall arrangement of the pilot burning zone: this preheated air is turned at the upstream end of the pilot burning zone through swirlers to mix with the original gas and air input (and the liquid fuel input when used) to provide more efficient combustion. One or more fuel injection stages (second stages) are provided for direct input of coal gas into the main burning zone. The countercurrent air coolant passages are connected to swirlers surrounding the input from each second stage to provide additional oxidant.

  5. Fuel injection staged sectoral combustor for burning low-BTU fuel gas

    DOEpatents

    Vogt, Robert L.

    1981-01-01

    A high-temperature combustor for burning low-BTU coal gas in a gas turbine is described. The combustor comprises a plurality of individual combustor chambers. Each combustor chamber has a main burning zone and a pilot burning zone. A pipe for the low-BTU coal gas is connected to the upstream end of the pilot burning zone; this pipe surrounds a liquid fuel source and is in turn surrounded by an air supply pipe; swirling means are provided between the liquid fuel source and the coal gas pipe and between the gas pipe and the air pipe. Additional preheated air is provided by counter-current coolant air in passages formed by a double wall arrangement of the walls of the main burning zone communicating with passages of a double wall arrangement of the pilot burning zone; this preheated air is turned at the upstream end of the pilot burning zone through swirlers to mix with the original gas and air input (and the liquid fuel input when used) to provide more efficient combustion. One or more fuel injection stages (second stages) are provided for direct input of coal gas into the main burning zone. The countercurrent air coolant passages are connected to swirlers surrounding the input from each second stage to provide additional oxidant.

  6. Aircraft Research and Technology for Future Fuels

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The potential characteristics of future aviation turbine fuels and the property effects of these fuels on propulsion system components are examined. The topics that are discussed include jet fuel supply and demand trends, the effects of refining variables on fuel properties, shekle oil processing, the characteristics of broadened property fuels, the effects of fuel property variations on combustor and fuel system performance, and combuster and fuel system technology for broadened property fuels.

  7. Aircraft measurements of biomass burning aerosol over West Africa during DABEX

    NASA Astrophysics Data System (ADS)

    Johnson, B. T.; Osborne, S. R.; Haywood, J. M.; Harrison, M. A. J.

    2008-12-01

    This paper investigates the properties of biomass burning aerosols over West Africa using data from the UK FAAM aircraft during the Dust and Biomass-burning Experiment (DABEX). Aged biomass burning aerosols were widespread across the region, often at altitudes up to 4 km. Fresh biomass burning aerosols were observed at low altitudes by flying through smoke plumes from agricultural fires. The aircraft measured aerosol size distributions, optical properties, and vertical distributions. Single scattering albedo varied from 0.73 to 0.93 (at 0.55 μm) in aerosol layers dominated by biomass burning aerosol. We attribute much of this variation to the variable proportion of mineral dust and biomass burning aerosol. We estimate the single scattering albedo of aged biomass burning aerosol to be around 0.81 with an instrumental uncertainty of ±0.05. External mixing, and possibly internal mixing, between the biomass burning aerosol and mineral dust presents an additional source of uncertainty in this estimate. The size distributions of biomass burning aerosols were dominated by particles with radii smaller than 0.35 μm. A 20% increase of count mean radius was observed when contrasting fresh and aged biomass burning aerosols, accompanied by changes in the shape of the size distribution. These changes suggest growth by coagulation and condensation. Extinction coefficients, asymmetry parameters, and Angstrom exponents are calculated from Mie theory, using the lognormal fits to the measured size distributions and assumed refractive indices.

  8. Combustion technology overview. [the use of broadened property aircraft fuels

    NASA Technical Reports Server (NTRS)

    Niedzwiecki, R. W.

    1980-01-01

    An overview of combustor technology developments required for use of broadened property fuels in jet aircraft is presented. The intent of current investigations is to determine the extent to which fuel properties can be varied, to obtain a data base of combustion - fuel quality effects, and to determine the trade-offs associated with broadened property fuels. Subcomponents of in-service combustors such as fuel injectors and liners, as well as air distributions and stoichiometry, are being altered to determine the extent to which fuel flexibility can be extended. Finally, very advanced technology consisting of new combustor concepts is being evolved to optimize the fuel flexibility of gas turbine combustors.

  9. Solid Oxide Fuel Cell APU Feasibility Study for a Long Range Commercial Aircraft Using UTC ITAPS Approach. Volume 1; Aircraft Propulsion and Subsystems Integration Evaluation

    NASA Technical Reports Server (NTRS)

    Srinivasan, Hari; Yamanis, Jean; Welch, Rick; Tulyani, Sonia; Hardin, Larry

    2006-01-01

    The objective of this contract effort was to define the functionality and evaluate the propulsion and power system benefits derived from a Solid Oxide Fuel Cell (SOFC) based Auxiliary Power Unit (APU) for a future long range commercial aircraft, and to define the technology gaps to enable such a system. The study employed technologies commensurate with Entry into Service (EIS) in 2015. United Technologies Corporation (UTC) Integrated Total Aircraft Power System (ITAPS) methodologies were used to evaluate system concepts to a conceptual level of fidelity. The technology benefits were captured as reductions of the mission fuel burn and emissions. The baseline aircraft considered was the Boeing 777-200ER airframe with more electric subsystems, Ultra Efficient Engine Technology (UEET) engines, and an advanced APU with ceramics for increased efficiency. In addition to the baseline architecture, four architectures using an SOFC system to replace the conventional APU were investigated. The mission fuel burn savings for Architecture-A, which has minimal system integration, is 0.16 percent. Architecture-B and Architecture-C employ greater system integration and obtain fuel burn benefits of 0.44 and 0.70 percent, respectively. Architecture-D represents the highest level of integration and obtains a benefit of 0.77 percent.

  10. Impact of future fuel properties on aircraft engines and fuel systems

    NASA Technical Reports Server (NTRS)

    Rudey, R. A.; Grobman, J. S.

    1978-01-01

    The effect of modifications in hydrocarbon jet fuels specifications on engine performance, component durability and maintenance, and aircraft fuel system performance is discussed. Specific topics covered include: specific fuel consumption; ignition at relight limits; exhaust emissions; combustor liner temperatures; carbon deposition; gum formation in fuel nozzles, erosion and corrosion of turbine blades and vanes; deposits in fuel system heat exchangers; and pumpability and flowability of the fuel. Data that evaluate the ability of current technology aircraft to accept fuel specification changes are presented, and selected technological advances that can reduce the severity of the problems are described and discussed.

  11. Effect of broadened-specification fuels on aircraft engines and fuel systems

    NASA Technical Reports Server (NTRS)

    Rudey, R. A.

    1979-01-01

    A wide variety of studies on the potential effects of broadened-specification fuels on future aircraft engines and fuel systems are summarized. The compositions and characteristics of aircraft fuels that may be derived from current and future crude-oil sources are described, and the most critical properties that may effect aircraft engines and fuel systems are identified and discussed. The problems that are most likely to be encountered because of changes in selected fuel properties are explored; and the related effects on engine performance, component durability and maintenance, and aircraft fuel-system performance are examined. The ability of current technology to accept possible future fuel specification changes is assessed and selected technological advances that can reduce the severity of the potential problems are illustrated.

  12. Molecular Aluminum Additive for Burn Enhancement of Hydrocarbon Fuels.

    PubMed

    Guerieri, Philip M; DeCarlo, Samantha; Eichhorn, Bryan; Connell, Terrence; Yetter, Richard A; Tang, Xin; Hicks, Zachary; Bowen, Kit H; Zachariah, Michael R

    2015-11-12

    Additives to hydrocarbon fuels are commonly explored to change the combustion dynamics, chemical distribution, and/or product integrity. Here we employ a novel aluminum-based molecular additive, Al(I) tetrameric cluster [AlBrNEt3]4 (Et = C2H5), to a hydrocarbon fuel and evaluate the resultant single-droplet combustion properties. This Al4 cluster offers a soluble alternative to nanoscale particulate additives that have recently been explored and may mitigate the observed problems of particle aggregation. Results show the [AlBrNEt3]4 additive to increase the burn rate constant of a toluene-diethyl ether fuel mixture by ∼20% in a room temperature oxygen environment with only 39 mM of active aluminum additive (0.16 wt % limited by additive solubility). In comparison, a roughly similar addition of nano-aluminum particulate shows no discernible difference in burn properties of the hydrocarbon fuel. High speed video shows the [AlBrNEt3]4 to induce microexplosive gas release events during the last ∼30% of the droplet combustion time. We attribute this to HBr gas release based on results of temperature-programmed reaction (TPR) experiments of the [AlBrNEt3]4 dosed with O2 and D2O. A possible mechanism of burn rate enhancement is presented that is consistent with microexplosion observations and TPR results.

  13. Biomass burning fuel consumption rates: a field measurement database

    NASA Astrophysics Data System (ADS)

    van Leeuwen, T. T.; van der Werf, G. R.; Hoffmann, A. A.; Detmers, R. G.; Rücker, G.; French, N. H. F.; Archibald, S.; Carvalho, J. A., Jr.; Cook, G. D.; de Groot, W. J.; Hély, C.; Kasischke, E. S.; Kloster, S.; McCarty, J. L.; Pettinari, M. L.; Savadogo, P.; Alvarado, E. C.; Boschetti, L.; Manuri, S.; Meyer, C. P.; Siegert, F.; Trollope, L. A.; Trollope, W. S. W.

    2014-06-01

    Landscape fires show large variability in the amount of biomass or fuel consumed per unit area burned. These fuel consumption (FC) rates depend on the biomass available to burn and the fraction of the biomass that is actually combusted, and can be combined with estimates of area burned to assess emissions. While burned area can be detected from space and estimates are becoming more reliable due to improved algorithms and sensors, FC rates are either modeled or taken selectively from the literature. We compiled the peer-reviewed literature on FC rates for various biomes and fuel categories to better understand FC rates and variability, and to provide a~database that can be used to constrain biogeochemical models with fire modules. We compiled in total 76 studies covering 10 biomes including savanna (15 studies, average FC of 4.6 t DM (dry matter) ha-1), tropical forest (n = 19, FC = 126), temperate forest (n = 11, FC = 93), boreal forest (n = 16, FC = 39), pasture (n = 6, FC = 28), crop residue (n = 4, FC = 6.5), chaparral (n = 2, FC = 32), tropical peatland (n = 4, FC = 314), boreal peatland (n = 2, FC = 42), and tundra (n = 1, FC = 40). Within biomes the regional variability in the number of measurements was sometimes large, with e.g. only 3 measurement locations in boreal Russia and 35 sites in North America. Substantial regional differences were found within the defined biomes: for example FC rates of temperate pine forests in the USA were 38% higher than Australian forests dominated by eucalypt trees. Besides showing the differences between biomes, FC estimates were also grouped into different fuel classes. Our results highlight the large variability in FC rates, not only between biomes but also within biomes and fuel classes. This implies that care should be taken with using averaged values, and our comparison with FC rates from GFED3 indicates that also modeling studies have difficulty in representing the dynamics governing FC.

  14. Study of advanced fuel system concepts for commercial aircraft

    NASA Technical Reports Server (NTRS)

    Coffinberry, G. A.

    1985-01-01

    An analytical study was performed in order to assess relative performance and economic factors involved with alternative advanced fuel systems for future commercial aircraft operating with broadened property fuels. The DC-10-30 wide-body tri-jet aircraft and the CF6-8OX engine were used as a baseline design for the study. Three advanced systems were considered and were specifically aimed at addressing freezing point, thermal stability and lubricity fuel properties. Actual DC-10-30 routes and flight profiles were simulated by computer modeling and resulted in prediction of aircraft and engine fuel system temperatures during a nominal flight and during statistical one-day-per-year cold and hot flights. Emergency conditions were also evaluated. Fuel consumption and weight and power extraction results were obtained. An economic analysis was performed for new aircraft and systems. Advanced system means for fuel tank heating included fuel recirculation loops using engine lube heat and generator heat. Environmental control system bleed air heat was used for tank heating in a water recirculation loop. The results showed that fundamentally all of the three advanced systems are feasible but vary in their degree of compatibility with broadened-property fuel.

  15. Properties of Aircraft Fuels and Related Materials

    DTIC Science & Technology

    1985-08-01

    type analyses:, Antistatic additives ;’ Fuel ~o5 aiants / Modified fuels; Corrosion inhibitors.oý V , Fuel composition. - aim ~ " me ~ GOA"fl 15 ft"’k...97 2. Effects of Fuel Corrosion Inhibitor Additives on the Electrical Conductivity of Fuels Containing Antistatic Additives ...determine level of trace metals which had caused thermal insta- bility; to determine the interactive effects of fuel additives ; and to aid in solving

  16. Increasing Fuel Utilization of Breed and Burn Reactors

    NASA Astrophysics Data System (ADS)

    Di Sanzo, Christian Diego

    Breed and Burn reactors (B&B), also referred to Traveling Wave Reactors, are fast spectrum reactors that can be fed indefinitely with depleted uranium only, once criticality is achieved without the need for fuel reprocessing. Radiation damage to the fuel cladding limits the fuel utilization of B&B reactors to ˜ 18-20% FIMA (Fissions of Initial Metal Atoms) -- the minimum burnup required for sustaining the B&B mode of operation. The fuel discharged from this type of cores contain ˜ 10% fissile plutonium. Such a high plutonium content poses environmental and proliferation concerns, but makes it possible to utilize the fuel for further energy production. The objectives of the research reported in this dissertation are to analyze the fuel cycle of B&B reactors and study new strategies to extend the fuel utilization beyond ˜ 18-20% FIMA. First, the B&B reactor physics is examined while recycling the fuel every 20% FIMA via a limited separation processing, using either the melt refining or AIROX dry processes. It was found that the maximum attainable burnup varies from 54% to 58% FIMA -- depending on the recycling process and on the fraction of neutrons lost via leakage and reactivity control. In Chapter 3 the discharge fuel characteristics of B&B reactors operating at 20% FIMA and 55% FIMA is analyzed and compared. It is found that the 20% FIMA reactor discharges a fuel with about ˜ 80% fissile plutonium over total plutonium content. Subsequently a new strategy of minimal reconditioning, called double cladding is proposed to extend the fuel utilization in specifically designed second-tier reactors. It is found that with this strategy it is possible to increase fuel utilization to 30% in a sodium fast reactor and up to 40% when a subcritical B&B core is driven by an accelerator-driven spallation neutron source. Lastly, a fuel cycle using Pressurized Water Reactors (PWR) to reduce the plutonium content of discharged B&B reactors is analyzed. It was found that it is

  17. Reductions in aircraft particulate emissions due to the use of Fischer-Tropsch fuels

    NASA Astrophysics Data System (ADS)

    Beyersdorf, A. J.; Timko, M. T.; Ziemba, L. D.; Bulzan, D.; Corporan, E.; Herndon, S. C.; Howard, R.; Miake-Lye, R.; Thornhill, K. L.; Winstead, E.; Wey, C.; Yu, Z.; Anderson, B. E.

    2013-06-01

    The use of alternative fuels for aviation is likely to increase due to concerns over fuel security, price stability and the sustainability of fuel sources. Concurrent reductions in particulate emissions from these alternative fuels are expected because of changes in fuel composition including reduced sulfur and aromatic content. The NASA Alternative Aviation Fuel Experiment (AAFEX) was conducted in January-February 2009 to investigate the effects of synthetic fuels on gas-phase and particulate emissions. Standard petroleum JP-8 fuel, pure synthetic fuels produced from natural gas and coal feedstocks using the Fischer-Tropsch (FT) process, and 50% blends of both fuels were tested in the CFM-56 engines on a DC-8 aircraft. To examine plume chemistry and particle evolution with time, samples were drawn from inlet probes positioned 1, 30, and 145 m downstream of the aircraft engines. No significant alteration to engine performance was measured when burning the alternative fuels. However, leaks in the aircraft fuel system were detected when operated with the pure FT fuels as a result of the absence of aromatic compounds in the fuel. Dramatic reductions in soot emissions were measured for both the pure FT fuels (reductions of 84% averaged over all powers) and blended fuels (64%) relative to the JP-8 baseline with the largest reductions at idle conditions. The alternative fuels also produced smaller soot (e.g. at 85% power, volume mean diameters were reduced from 78 nm for JP-8 to 51 nm for the FT fuel), which may reduce their ability to act as cloud condensation nuclei (CCN). The reductions in particulate emissions are expected for all alternative fuels with similar reductions in fuel sulfur and aromatic content regardless of the feedstock. As the plume cools downwind of the engine, nucleation-mode aerosols form. For the pure FT fuels, reductions (94% averaged over all powers) in downwind particle number emissions were similar to those measured at the exhaust plane (84

  18. Preliminary analysis of aircraft fuel systems for use with broadened specification jet fuels

    NASA Technical Reports Server (NTRS)

    Pasion, A. J.; Thomas, I.

    1977-01-01

    An analytical study was conducted on the use of broadened specification hydrocarbon fuels in present day aircraft. A short range Boeing 727 mission and three long range Boeing 747 missions were used as basis of calculation for one-day-per-year extreme values of fuel loading, airport ambient and altitude ambient temperatures with various seasonal and climatic conditions. Four hypothetical fuels were selected; two high-vapor-pressure fuels with 35 kPa and 70 kPa RVP and two high-freezing-point fuels with -29 C and -18 C freezing points. In-flight fuel temperatures were predicted by Boeing's aircraft fuel tank thermal analyzer computer program. Boil-off rates were calculated for the high vapor pressure fuels and heating/insulation requirements for the high freezing point fuels were established. Possible minor and major heating system modifications were investigated with respect to heat output, performance and economic penalties for the high freezing point fuels.

  19. Study of fuel systems for LH2-fueled subsonic transport aircraft, volume 1

    NASA Technical Reports Server (NTRS)

    Brewer, G. D.; Morris, R. E.; Davis, G. W.; Versaw, E. F.; Cunnington, G. R., Jr.; Riple, J. C.; Baerst, C. F.; Garmong, G.

    1978-01-01

    Several engine concepts examined to determine a preferred design which most effectively exploits the characteristics of hydrogen fuel in aircraft tanks received major emphasis. Many candidate designs of tank structure and cryogenic insulation systems were evaluated. Designs of all major elements of the aircraft fuel system including pumps, lines, valves, regulators, and heat exchangers received attention. Selected designs of boost pumps to be mounted in the LH2 tanks, and of a high pressure pump to be mounted on the engine were defined. A final design of LH2-fueled transport aircraft was established which incorporates a preferred design of fuel system. That aircraft was then compared with a conventionally fueled counterpart designed to equivalent technology standards.

  20. Experimental investigation and modeling of an aircraft Otto engine operating with gasoline and heavier fuels

    NASA Astrophysics Data System (ADS)

    Saldivar Olague, Jose

    A Continental "O-200" aircraft Otto-cycle engine has been modified to burn diesel fuel. Algebraic models of the different processes of the cycle were developed from basic principles applied to a real engine, and utilized in an algorithm for the simulation of engine performance. The simulation provides a means to investigate the performance of the modified version of the Continental engine for a wide range of operating parameters. The main goals of this study are to increase the range of a particular aircraft by reducing the specific fuel consumption of the engine, and to show that such an engine can burn heavier fuels (such as diesel, kerosene, and jet fuel) instead of gasoline. Such heavier fuels are much less flammable during handling operations making them safer than aviation gasoline and very attractive for use in flight operations from naval vessels. The cycle uses an electric spark to ignite the heavier fuel at low to moderate compression ratios, The stratified charge combustion process is utilized in a pre-chamber where the spray injection of the fuel occurs at a moderate pressure of 1200 psi (8.3 MPa). One advantage of fuel injection into the combustion chamber instead of into the intake port, is that the air-to-fuel ratio can be widely varied---in contrast to the narrower limits of the premixed combustion case used in gasoline engines---in order to obtain very lean combustion. Another benefit is that higher compression ratios can be attained in the modified cycle with heavier fuels. The combination of injection into the chamber for lean combustion, and higher compression ratios allow to limit the peak pressure in the cylinder, and to avoid engine damage. Such high-compression ratios are characteristic of Diesel engines and lead to increase in thermal efficiency without pre-ignition problems. In this experimental investigation, operations with diesel fuel have shown that considerable improvements in the fuel efficiency are possible. The results of

  1. Comparison of PM emissions from a commercial jet engine burning conventional, biomass, and Fischer-Tropsch fuels.

    PubMed

    Lobo, Prem; Hagen, Donald E; Whitefield, Philip D

    2011-12-15

    Rising fuel costs, an increasing desire to enhance security of energy supply, and potential environmental benefits have driven research into alternative renewable fuels for commercial aviation applications. This paper reports the results of the first measurements of particulate matter (PM) emissions from a CFM56-7B commercial jet engine burning conventional and alternative biomass- and, Fischer-Tropsch (F-T)-based fuels. PM emissions reductions are observed with all fuels and blends when compared to the emissions from a reference conventional fuel, Jet A1, and are attributed to fuel properties associated with the fuels and blends studied. Although the alternative fuel candidates studied in this campaign offer the potential for large PM emissions reductions, with the exception of the 50% blend of F-T fuel, they do not meet current standards for aviation fuel and thus cannot be considered as certified replacement fuels. Over the ICAO Landing Takeoff Cycle, which is intended to simulate aircraft engine operations that affect local air quality, the overall PM number-based emissions for the 50% blend of F-T fuel were reduced by 34 ± 7%, and the mass-based emissions were reduced by 39 ± 7%.

  2. Integral Aircraft Fuel Tank Leak Classification

    DTIC Science & Technology

    1980-01-01

    effects of the following parameters on the rate of surface dispersion of fuels were examined: fuel type, leakage rate, surface material, fuel and...ranging from 3.34C to 98 C (38OF to 209’F). The vapor pressure of the fuel at the test temperature has a very pronounced effect on the propensity of the...Fuels and the Effect of Flow Rate 8 Effect of Temperature 14 Effect of Air Flow Rate 14 Effect of Panel Angle of Inclination 19 Effect of Panel

  3. Biomass burning fuel consumption rates: a field measurement database

    NASA Astrophysics Data System (ADS)

    van Leeuwen, T. T.; van der Werf, G. R.; Hoffmann, A. A.; Detmers, R. G.; Rücker, G.; French, N. H. F.; Archibald, S.; Carvalho, J. A., Jr.; Cook, G. D.; de Groot, W. J.; Hély, C.; Kasischke, E. S.; Kloster, S.; McCarty, J. L.; Pettinari, M. L.; Savadogo, P.; Alvarado, E. C.; Boschetti, L.; Manuri, S.; Meyer, C. P.; Siegert, F.; Trollope, L. A.; Trollope, W. S. W.

    2014-12-01

    Landscape fires show large variability in the amount of biomass or fuel consumed per unit area burned. Fuel consumption (FC) depends on the biomass available to burn and the fraction of the biomass that is actually combusted, and can be combined with estimates of area burned to assess emissions. While burned area can be detected from space and estimates are becoming more reliable due to improved algorithms and sensors, FC is usually modeled or taken selectively from the literature. We compiled the peer-reviewed literature on FC for various biomes and fuel categories to understand FC and its variability better, and to provide a database that can be used to constrain biogeochemical models with fire modules. We compiled in total 77 studies covering 11 biomes including savanna (15 studies, average FC of 4.6 t DM (dry matter) ha-1 with a standard deviation of 2.2), tropical forest (n = 19, FC = 126 ± 77), temperate forest (n = 12, FC = 58 ± 72), boreal forest (n = 16, FC = 35 ± 24), pasture (n = 4, FC = 28 ± 9.3), shifting cultivation (n = 2, FC = 23, with a range of 4.0-43), crop residue (n = 4, FC = 6.5 ± 9.0), chaparral (n = 3, FC = 27 ± 19), tropical peatland (n = 4, FC = 314 ± 196), boreal peatland (n = 2, FC = 42 [42-43]), and tundra (n = 1, FC = 40). Within biomes the regional variability in the number of measurements was sometimes large, with e.g. only three measurement locations in boreal Russia and 35 sites in North America. Substantial regional differences in FC were found within the defined biomes: for example, FC of temperate pine forests in the USA was 37% lower than Australian forests dominated by eucalypt trees. Besides showing the differences between biomes, FC estimates were also grouped into different fuel classes. Our results highlight the large variability in FC, not only between biomes but also within biomes and fuel classes. This implies that substantial uncertainties are associated with using biome-averaged values to represent FC for whole

  4. Microstructural Characterization of High Burn-up Mixed Oxide Fast Reactor Fuel

    SciTech Connect

    Melissa C. Teague; Brian P. Gorman; Steven L. Hayes; Douglas L. Porter; Jeffrey King

    2013-10-01

    High burn-up mixed oxide fuel with local burn-ups of 3.4–23.7% FIMA (fissions per initial metal atom) were destructively examined as part of a research project to understand the performance of oxide fuel at extreme burn-ups. Optical metallography of fuel cross-sections measured the fuel-to-cladding gap, clad thickness, and central void evolution in the samples. The fuel-to-cladding gap closed significantly in samples with burn-ups below 7–9% FIMA. Samples with burn-ups in excess of 7–9% FIMA had a reopening of the fuel-to-cladding gap and evidence of joint oxide-gain (JOG) formation. Signs of axial fuel migration to the top of the fuel column were observed in the fuel pin with a peak burn-up of 23.7% FIMA. Additionally, high burn-up structure (HBS) was observed in the two highest burn-up samples (23.7% and 21.3% FIMA). The HBS layers were found to be 3–5 times thicker than the layers found in typical LWR fuel. The results of the study indicate that formation of JOG and or HBS prevents any significant fuel-cladding mechanical interaction from occurring, thereby extending the potential life of the fuel elements.

  5. Study of methane fuel for subsonic transport aircraft

    NASA Technical Reports Server (NTRS)

    Carson, L. K.; Davis, G. W.; Versaw, E. F.; Cunnington, G. R., Jr.; Daniels, E. J.

    1980-01-01

    The cost and performance were defined for commercial transport using liquid methane including its fuel system and the ground facility complex required for the processing and storage of methane. A cost and performance comparison was made with Jet A and hydrogen powered aircraft of the same payload and range capability. Extensive design work was done on cryogenic fuel tanks, insulation systems as well as the fuel system itself. Three candidate fuel tank locations were evaluated, i.e., fuselage tanks, wing tanks or external pylon tanks.

  6. Aircraft-Fuel-Tank Design for Liquid Hydrogen

    NASA Technical Reports Server (NTRS)

    Reynolds, T W

    1955-01-01

    Some of the considerations involved in the design of aircraft fuel tanks for liquid hydrogen are discussed herein. Several of the physical properties of metals and thermal insulators in the temperature range from ambient to liquid-hydrogen temperatures are assembled. Calculations based on these properties indicate that it is possible to build a large-size liquid-hydrogen fuel tank which (1) will weigh less then 15 percent of the fuel weight, (2) will have a hydrogen vaporization rate less than 30 percent of the cruise fuel-flow rate, and (3) can be held in a stand-by condition and readied for flight in a short time.

  7. Economic impact of fuel properties on turbine powered business aircraft

    NASA Technical Reports Server (NTRS)

    Powell, F. D.

    1984-01-01

    The principal objective was to estimate the economic impact on the turbine-powered business aviation fleet of potential changes in the composition and properties of aviation fuel. Secondary objectives include estimation of the sensitivity of costs to specific fuel properties, and an assessment of the directions in which further research should be directed. The study was based on the published characteristics of typical and specific modern aircraft in three classes; heavy jet, light jet, and turboprop. Missions of these aircraft were simulated by computer methods for each aircraft for several range and payload combinations, and assumed atmospheric temperatures ranging from nominal to extremely cold. Five fuels were selected for comparison with the reference fuel, nominal Jet A. An overview of the data, the mathematic models, the data reduction and analysis procedure, and the results of the study are given. The direct operating costs of the study fuels are compared with that of the reference fuel in the 1990 time-frame, and the anticipated fleet costs and fuel break-even costs are estimated.

  8. Coated Particle and Deep Burn Fuels Monthly Highlights December 2010

    SciTech Connect

    Snead, Lance Lewis; Bell, Gary L; Besmann, Theodore M

    2011-01-01

    During FY 2011 the CP & DB Program will report Highlights on a monthly basis, but will no longer produce Quarterly Progress Reports. Technical details that were previously included in the quarterly reports will be included in the appropriate Milestone Reports that are submitted to FCRD Program Management. These reports will also be uploaded to the Deep Burn website. The Monthly Highlights report for November 2010, ORNL/TM-2010/323, was distributed to program participants on December 9, 2010. The final Quarterly for FY 2010, Deep Burn Program Quarterly Report for July - September 2010, ORNL/TM-2010/301, was announced to program participants and posted to the website on December 28, 2010. This report discusses the following: (1) Thermochemical Data and Model Development - (a) Thermochemical Modeling, (b) Core Design Optimization in the HTR (high temperature helium-cooled reactor) Pebble Bed Design (INL), (c) Radiation Damage and Properties; (2) TRISO (tri-structural isotropic) Development - (a) TRU (transuranic elements) Kernel Development, (b) Coating Development; (3) LWR Fully Ceramic Fuel - (a) FCM Fabrication Development, (b) FCM Irradiation Testing (ORNL); (4) Fuel Performance and Analytical Analysis - Fuel Performance Modeling (ORNL).

  9. Radiative forcing from household fuel burning in Asia

    NASA Astrophysics Data System (ADS)

    Aunan, Kristin; Berntsen, Terje K.; Myhre, Gunnar; Rypdal, Kristin; Streets, David G.; Woo, Jung-Hun; Smith, Kirk R.

    Household fuel use in developing countries, particularly as biomass and coal, is a major source of carbonaceous aerosols and other air pollutants affecting health and climate. Using state-of-the-art emission inventories, a global three-dimensional photochemical tracer/transport model of the troposphere, and a global radiative transfer model based on methods presented in the latest IPCC Assessment Report (2007-AR4), we estimate the radiative forcing (RF) attributable to household fuel combustion in Asia in terms of current global annual-mean RF and future global integrated RF for a one-year pulse of emissions (2000) over two time horizons (100 and 20 years). Despite the significant emissions of black carbon (BC) aerosols, these estimates indicate that shorter-lived (non-Kyoto) air pollutants from household fuel use in the region overall seem to exert a small net negative RF because of the strong influence of reflective aerosols. There are, however, major uncertainties in emission estimates for solid fuel burning, and about the sustainability of household fuel wood harvesting in Asia (the carbon neutrality of harvesting). In addition, there is still substantial uncertainty associated with the BC radiative forcing. As a result we find that the sign of the RF from household biomass burning in the region cannot be established. While recognizing the value of integrating climate change and air pollution policies, we are concerned that for a 'Kyoto style' post-Kyoto treaty (with global cap-and-trade and the Global Warming Potential as the metric) expanding the basket of components with a selection of short-lived species without also including the wider range of co-emitted species may lead to unintended consequences for global-scale climate. Additional measurement, modelling, and policy research is urgently needed to reduce the uncertainties so that the net impact on climate of emissions and mitigation measures in this sector can be accurately assessed.

  10. Advanced Aircraft Fuel Evaluation. Phase 1.

    DTIC Science & Technology

    1987-03-01

    sensible heat they can absorb and the endothermic heat of dehydrogenation at 450-500*C to the corresponding aromatic hydro- carbons. The aromatics in...hydrogen released in the endothermic dehydrogenation. Having absorbed this heat from the airframe, the fuel now has an effective heating value...reducing the heat absorbing capability of the fuel. The presence of an alkyl group increases the molecular weight of the fuel relative to the amount of

  11. Deep-Burn Modular Helium Reactor Fuel Development Plan

    SciTech Connect

    McEachern, D

    2002-12-02

    This document contains the workscope, schedule and cost for the technology development tasks needed to satisfy the fuel and fission product transport Design Data Needs (DDNs) for the Gas Turbine-Modular Helium Reactor (GT-MHR), operating in its role of transmuting transuranic (TRU) nuclides in spent fuel discharged from commercial light-water reactors (LWRs). In its application for transmutation, the GT-MHR is referred to as the Deep-Burn MHR (DB-MHR). This Fuel Development Plan (FDP) describes part of the overall program being undertaken by the U.S. Department of Energy (DOE), utilities, and industry to evaluate the use of the GT-MHR to transmute transuranic nuclides from spent nuclear fuel. The Fuel Development Plan (FDP) includes the work on fuel necessary to support the design and licensing of the DB-MHR. The FDP is organized into ten sections. Section 1 provides a summary of the most important features of the plan, including cost and schedule information. Section 2 describes the DB-MHR concept, the features of its fuel and the plan to develop coated particle fuel for transmutation. Section 3 describes the knowledge base for fabrication of coated particles, the experience with irradiation performance of coated particle fuels, the database for fission product transport in HTGR cores, and describes test data and calculations for the performance of coated particle fuel while in a repository. Section 4 presents the fuel performance requirements in terms of as-manufactured quality and performance of the fuel coatings under irradiation and accident conditions. These requirements are provisional because the design of the DB-MHR is in an early stage. However, the requirements are presented in this preliminary form to guide the initial work on the fuel development. Section 4 also presents limits on the irradiation conditions to which the coated particle fuel can be subjected for the core design. These limits are based on past irradiation experience. Section 5 describes

  12. Burning Fossil Fuels: Impact of Climate Change on Health.

    PubMed

    Sommer, Alfred

    2016-01-01

    A recent, sophisticated granular analysis of climate change in the United States related to burning fossil fuels indicates a high likelihood of dramatic increases in temperature, wet-bulb temperature, and precipitation, which will dramatically impact the health and well-being of many Americans, particularly the young, the elderly, and the poor and marginalized. Other areas of the world, where they lack the resources to remediate these weather impacts, will be even more greatly affected. Too little attention is being paid to the impending health impact of accumulating greenhouse gases.

  13. Power characteristics of fuels for aircraft engines

    NASA Technical Reports Server (NTRS)

    Dickinson, W S; James, W S; Roberts, E W; Gage, V R; Harper, D R Iii

    1920-01-01

    Report presents the summation of results obtained in the testing of fuels of various compositions and characteristics in the altitude laboratory. The data upon which this report is based has had an important influence upon the writing of specifications for the various grades of aviation fuels.

  14. End-to-end testing. [to verify electrical equipment failure due to carbon fibers released in aircraft-fuel fires

    NASA Technical Reports Server (NTRS)

    Pride, R. A.

    1979-01-01

    The principle objective of the kinds of demonstration tests that are discussed is to try to verify whether or not carbon fibers that are released by burning composite parts in an aircraft-fuel fires can produce failures in electrical equipment. A secondary objective discussed is to experimentally validate the analytical models for some of the key elements in the risk analysis. The approach to this demonstration testing is twofold: limited end-to-end test are to be conducted in a shock tube; and planning for some large outdoor burn tests is being done.

  15. Studying the effects of fuel treatment based on burn probability on a boreal forest landscape.

    PubMed

    Liu, Zhihua; Yang, Jian; He, Hong S

    2013-01-30

    Fuel treatment is assumed to be a primary tactic to mitigate intense and damaging wildfires. However, how to place treatment units across a landscape and assess its effectiveness is difficult for landscape-scale fuel management planning. In this study, we used a spatially explicit simulation model (LANDIS) to conduct wildfire risk assessments and optimize the placement of fuel treatments at the landscape scale. We first calculated a baseline burn probability map from empirical data (fuel, topography, weather, and fire ignition and size data) to assess fire risk. We then prioritized landscape-scale fuel treatment based on maps of burn probability and fuel loads (calculated from the interactions among tree composition, stand age, and disturbance history), and compared their effects on reducing fire risk. The burn probability map described the likelihood of burning on a given location; the fuel load map described the probability that a high fuel load will accumulate on a given location. Fuel treatment based on the burn probability map specified that stands with high burn probability be treated first, while fuel treatment based on the fuel load map specified that stands with high fuel loads be treated first. Our results indicated that fuel treatment based on burn probability greatly reduced the burned area and number of fires of different intensities. Fuel treatment based on burn probability also produced more dispersed and smaller high-risk fire patches and therefore can improve efficiency of subsequent fire suppression. The strength of our approach is that more model components (e.g., succession, fuel, and harvest) can be linked into LANDIS to map the spatially explicit wildfire risk and its dynamics to fuel management, vegetation dynamics, and harvesting.

  16. 19 CFR 10.62b - Aircraft turbine fuel.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... consumption, with duty deposited, as required under the applicable regulations (see part 144 of this chapter... withdrawal for consumption shall be filed and duties shall be deposited for the excess of fuel so withdrawn over that used on aircraft so qualifying. Such withdrawal shall be filed and such duties shall...

  17. Analytical Techniques for Aromatic Components in Aircraft Fuels.

    DTIC Science & Technology

    1979-10-01

    IN AIRCRAFT FUELS J . Scott Warner Richard P. Kenan Battelle Columbus Laboratories 505 King Avenue Columbus, Ohio 43201 DTIC October 1979 ELECTE JUL...1979. Dr. J . Scott Warner, Battelle’s Columbus Laboratories, was the Principal Investigator for the program and had the primary responsibility for

  18. Autoignition characteristics of aircraft-type fuels

    NASA Technical Reports Server (NTRS)

    Spadaccini, L. J.; Tevelde, J. A.

    1980-01-01

    The ignition delay characteristics of Jet A, JP 4, no. 2 diesel, cetane and an experimental referee broad specification (ERBS) fuel in air at inlet temperatures up to 1000 K, pressures of 10, 15, 20, 25 and 30 atm, and fuel air equivalence ratios of 0.3, 0.5, 0.7 and 1.0 were mapped. Ignition delay times in the range of 1 to 50 msec at freestream flow velocities ranging from 20 to 100 m/sec were obtained using a continuous flow test apparatus which permitted independent variation and evaluation of the effect of temperature, pressure, flow rate, and fuel/air ratio. The ignition delay times for all fuels tested appeared to correlate with the inverse of pressure and the inverse exponent of temperature. With the exception of pure cetane, which had the shortest ignition delay times, the differences between the fuels tested did not appear to be significant. The apparent global activation energies for the typical gas turbine fuels ranged from 38 to 40 kcal/mole, while the activation energy determined for cetane was 50 kcal/mole. In addition, the data indicate that for lean mixtures, ignition delay times decrease with increasing equivalence ratio. It was also noted that physical (apparatus dependent) phenomena, such as mixing (i.e., length and number of injection sites) and airstream cooling (due to fuel heating, vaporization and convective heat loss) can have an important effect on the ignition delay.

  19. Assessment of burning characteristics of aircraft interior materials

    NASA Technical Reports Server (NTRS)

    Grand, A. F.; Valys, A. J.

    1981-01-01

    The performance of a series of seat cushion design constructions was compared based on their heat and smoke release characteristics. Tests were conducted in a room size calorimeter instrumented for measuring weight loss, rate of heat release, smoke and volatile decomposition products and the cumulative energy release. Baseline data were obtained from burn tests conducted on commercial airline salvage sets as a comparison with more advanced seat designs. A toxicological assessment of smoke and fire gases involved the exposure of test animals and their biological responses ascertained. Relative toxicological hazards of the combustion gases are discussed based on the animal response studies and the analysis of the combustion gases.

  20. Clean-burning fuels produced from low-grade coal

    SciTech Connect

    1995-03-01

    Under the acid rain program, operators of large combustion units are required to reduce their emissions of sulfur oxides (SO{sub x}) and nitrogen oxides (NO{sub x}). Although the program provides significant flexibility through its system of marketable emission allowances, regulated sources needing to reduce SO{sub x} emissions typically choose one of the following two options: (1) switch to a low-sulfur fuel, or (2) add end-of-pipe controls. Because it is naturally low in sulfur, one good candidate for fuel switching is coal mined from the Powder River basin in northeast Wyoming. The Encoal Corporation (Gillette, Wyoming) has attempted to improve the economics of using Powder River coal by installing a coal liquification plant at an existing mine near Gillette. The plant, cofunded by the Department of Energy (DOE) and Zeigler Coal Holding Company (the parent company to Encoal), has demonstrated commercial-scale application of a liquids-from-coal (LFC) process developed by SGI International. The LFC process represents a middle-of-the-road approach to coal treatment. As described, here, the process converts high-moisture, low-grade coal into process-derived fuel (PDF-an upgraded solid coal product) and coal-derived liquids (CDL-fuel-oil type liquids). The LFC process also produces an organic gas stream, which is burned internally as an energy source. Finally, the LFC process can be adapted, if necessary, to remove sulfur from high-sulfur coal. 1 ref., 1 fig.

  1. Vertical feed stick wood fuel burning furnace system

    DOEpatents

    Hill, Richard C.

    1982-01-01

    A stove or furnace for efficient combustion of wood fuel includes a vertical feed combustion chamber (15) for receiving and supporting wood fuel in a vertical attitude or stack. A major upper portion of the combustion chamber column comprises a water jacket (14) for coupling to a source of water or heat transfer fluid for convection circulation of the fluid. The locus (31) of wood fuel combustion is thereby confined to the refractory base of the combustion chamber. A flue gas propagation delay channel (34) extending laterally from the base of the chamber affords delayed travel time in a high temperature refractory environment sufficient to assure substantially complete combustion of the gaseous products of wood burning with forced air prior to extraction of heat in heat exchanger (16). Induced draft draws the fuel gas and air mixture laterally through the combustion chamber and refractory high temperature zone to the heat exchanger and flue. Also included are active sources of forced air and induced draft, multiple circuit couplings for the recovered heat, and construction features in the refractory material substructure and metal component superstructure.

  2. Vertical feed stick wood fuel burning furnace system

    DOEpatents

    Hill, Richard C.

    1984-01-01

    A new and improved stove or furnace for efficient combustion of wood fuel including a vertical feed combustion chamber for receiving and supporting wood fuel in a vertical attitude or stack, a major upper portion of the combustion chamber column comprising a water jacket for coupling to a source of water or heat transfer fluid and for convection circulation of the fluid for confining the locus of wood fuel combustion to the bottom of the vertical gravity feed combustion chamber. A flue gas propagation delay channel extending from the laterally directed draft outlet affords delayed travel time in a high temperature environment to assure substantially complete combustion of the gaseous products of wood burning with forced air as an actively induced draft draws the fuel gas and air mixture laterally through the combustion and high temperature zone. Active sources of forced air and induced draft are included, multiple use and circuit couplings for the recovered heat, and construction features in the refractory material substructure and metal component superstructure.

  3. Aircraft Integral Fuel Tank Corrosion Study

    DTIC Science & Technology

    2007-11-02

    sensor is formed by two concentric metallic electrodes, separated by an insulator material , between which an electric current circulates when a given... materials are used to make the mentioned current, proportional to the concentration of corrosive contaminants in the water and to the amount of microbial...contamination level, detected in the respective fuel tank. REFERENCES 1. C. B. Ward. Corrosion resulting from corrosion fuel tank contamination. Materials

  4. Nonlinear burn condition control in tokamaks using isotopic fuel tailoring

    NASA Astrophysics Data System (ADS)

    Boyer, Mark D.; Schuster, Eugenio

    2015-08-01

    One of the fundamental problems in tokamak fusion reactors is how to control the plasma density and temperature in order to regulate the amount of fusion power produced by the device. Control of these parameters will be critical to the success of burning plasma experiments like ITER. The most previous burn condition control efforts use either non-model based control designs or techniques based on models linearized around particular operating points. Such strategies limit the potential operational space and must be carefully retuned or redesigned to accommodate changes in operating points or plasma parameters. In this work, a nonlinear dynamic model of the spatial averages of energy and ion species densities is used to synthesize a nonlinear feedback controller for stabilizing the burn condition. The nonlinear model-based control strategy guarantees a much larger operational space than previous linear controllers. Because it is not designed around a particular operating point, the controller can be used to move from one burn condition to another. The proposed scheme first attempts to use regulation of the auxiliary heating power to reject temperature perturbations, then, if necessary, uses isotopic fuel tailoring as a way to reduce fusion heating during positive temperature perturbations. A global model of hydrogen recycling is incorporated into the model used for design and simulation, and the proposed control scheme is tested for a range of recycling model parameters. As we find the possibility of changing the isotopic mix can be limited for certain unfavorable recycling conditions, we also consider impurity injection as a back-up method for controlling the system. A simple supervisory control strategy is proposed to switch between the primary and back-up control schemes based on stability and performance criteria. A zero-dimensional simulation study is used to study the performance of the control scheme for several scenarios and model parameters. Finally, a one

  5. Fire hazard after prescribed burning in a gorse shrubland: implications for fuel management.

    PubMed

    Marino, Eva; Guijarro, Mercedes; Hernando, Carmen; Madrigal, Javier; Díez, Carmen

    2011-03-01

    Prescribed burning is commonly used to prevent accumulation of biomass in fire-prone shrubland in NW Spain. However, there is a lack of knowledge about the efficacy of the technique in reducing fire hazard in these ecosystems. Fire hazard in burned shrubland areas will depend on the initial capacity of woody vegetation to recover and on the fine ground fuels existing after fire. To explore the effect that time since burning has on fire hazard, experimental tests were performed with two fuel complexes (fine ground fuels and regenerated shrubs) resulting from previous prescribed burnings conducted in a gorse shrubland (Ulex europaeus L.) one, three and five years earlier. A point-ignition source was used in burning experiments to assess ignition and initial propagation success separately for each fuel complex. The effect of wind speed was also studied for shrub fuels, and several flammability parameters were measured. Results showed that both ignition and initial propagation success of fine ground fuels mainly depended on fuel depth and were independent of time since burning, although flammability parameters indicated higher fire hazard three years after burning. In contrast, time since burning increased ignition and initial propagation success of regenerated shrub fuels, as well as the flammability parameters assessed, but wind speed had no significant effect. The combination of results of fire hazard for fine ground fuels and regenerated shrubs according to the variation in relative coverage of each fuel type after prescribed burning enabled an assessment of integrated fire hazard in treated areas. The present results suggest that prescribed burning is a very effective technique to reduce fire hazard in the study area, but that fire hazard will be significantly increased by the third year after burning. These results are valuable for fire prevention and fuel management planning in gorse shrubland areas.

  6. Fuel conservation possibilities for terminal area compatible aircraft

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Design features and operational procedures are identified, which would reduce fuel consumption of future transport aircraft. The fuel-saving potential can be realized during the last decade of this century only if the necessary research and technology programs are implemented in the areas of composite primary structure, airfoil/wing design, and stability augmentation systems. The necessary individual R and T programs are defined. The sensitivity to fuel usage of several design parameters (wing geometry, cruise speed, propulsion) is investigated, and the results applied to a candidate 18, 140-kg (40,000-lb) payload, 5556-km (3000-nmi) transport design. Technical and economic comparisons are made with current commercial aircraft and other advanced designs.

  7. Hygroscopic Properties of Aircraft Engine Exhaust Aerosol Produced From Traditional and Alternative Fuels

    NASA Astrophysics Data System (ADS)

    Moore, R.; Ziemba, L. D.; Beyersdorf, A. J.; Thornhill, K. L.; Winstead, E. L.; Crumeyrolle, S.; Chen, G.; Anderson, B. E.

    2012-12-01

    Aircraft emissions of greenhouse gases and aerosols constitute an important component of anthropogenic climate forcing, of which aerosol-cloud interactions remain poorly understood. It is currently thought that the ability of these aerosols to alter upper tropospheric cirrus cloud properties may produce radiative forcings many times larger than the impact of linear contrails alone and which may partially offset the impact of greenhouse gas emissions from aviation (Burkhardt and Karcher, Nature, 2011). Consequently, it is important to characterize the ability of these engine-emitted aerosol to act as cloud condensation nuclei (CCN) and ice nuclei (IN) to form clouds. While a number of studies in the literature have examined aerosol-cloud interactions for laboratory-generated soot or from aircraft engines burning traditional fuels, limited attention has been given to how switching to alternative jet fuels impacts the ability of engine-emitted aerosols to form clouds. The key to understanding these changes is the aerosol hygroscopicity. To address this need, the second NASA Alternative Aviation Fuel Experiment (AAFEX-II) was conducted in 2011 to examine the aerosol emissions from the NASA DC-8 under a variety of different engine power and fuel type conditions. Five fuel types were considered including traditional JP-8 fuel, synthetic Fischer-Tropsh (FT) fuel , sulfur-doped FT fuel (FTS) , hydrotreated renewable jet (HRJ) fuel, and a 50:50 blend of JP-8 with HRJ. Emissions were sampled from the DC-8 on the airport jetway at a distance of 145 meters downwind of the engine by a comprehensive suite of aerosol instrumentation that provided information on the aerosol concentration, size distribution, soot mass, and CCN activity. Concurrent measurements of carbon dioxide were used to account for plume dilution so that characteristic emissions indices could be determined. It is found that both engine power and fuel type significantly influence the hygroscopic properties of

  8. Design of short haul aircraft for fuel conservation

    NASA Technical Reports Server (NTRS)

    Bowden, M. K.; Sweet, H. S.; Waters, M. H.

    1975-01-01

    Current jet fuel prices of twice the 1972 level have significantly changed the characteristics of airplane design for best economy. The results of a contract with the NASA Ames Advanced Concepts and Missions Division confirmed the economic desirability of lower design cruise speeds and higher aspect-ratio wings compared to designs developed in the by-gone era of low fuel price. Evaluation of potential fuel conservation for short-haul aircraft showed that an interaction of airfoil technology and desirable engine characteristics is important: the supercritical airfoil permits higher aspect ratio wings with lower sweep; these, in turn, lower the cruise thrust requirements so that engines with higher bypass ratios are better matched in terms of lapse rate; lower cruise speeds (which are also better for fuel and operating cost economy) push the desired bypass ratio up further. Thus, if fuel prices remain high, or rise further, striking reductions in community noise level can be achieved as a fallout in development of a 1980s airplane and engine. Analyses are presented of developmental trends in the design of short-haul aircraft with lower cruise speeds and higher aspect-ratio wings, and the effects on fuel consumption of design field length, powered lift concepts, and turboprop as well as turbofan propulsion are discussed.

  9. Impact of future fuel properties on aircraft engines and fuel systems

    NASA Technical Reports Server (NTRS)

    Rudey, R. A.; Grobman, J. S.

    1978-01-01

    From current projections of the availability of high-quality petroleum crude oils, it is becoming increasingly apparent that the specifications for hydrocarbon jet fuels may have to be modified. The problems that are most likely to be encountered as a result of these modifications relate to engine performance, component durability and maintenance, and aircraft fuel-system performance. The effect on engine performance will be associated with changes in specific fuel consumption, ignition at relight limits, at exhaust emissions. Durability and maintenance will be affected by increases in combustor liner temperatures, carbon deposition, gum formation in fuel nozzles, and erosion and corrosion of turbine blades and vanes. Aircraft fuel-system performance will be affected by increased deposits in fuel-system heat exchangers and changes in the pumpability and flowability of the fuel. The severity of the potential problems is described in terms of the fuel characteristics most likely to change in the future. Recent data that evaluate the ability of current-technology aircraft to accept fuel specification changes are presented, and selected technological advances that can reduce the severity of the problems are described and discussed.

  10. Burning chemical wastes as fuels in cement kilns

    SciTech Connect

    Lauber, J.D.

    1982-07-01

    Hazardous wastes in the environment represent one of our most serious problems. Ever increasing quantities of toxic wastes have contaminated our land, air, and water. Lack of adequate hazardous waste disposal facilities is a critical problem. Landfilling toxic wastes is no longer considered safe. The tragedy of the Love Canal has demonstrated the need for proper hazardous waste disposal facilities. The best organic chemical waste disposal method is process incineration. Cement kilns have been used for burning toxic chemical industrial wastes in Canada, Michigan, New York, Sweden, etc. Existing cement kilns, when properly operated, can destroy most organic chemical wastes. Even the most complex chlorinated hydrocarbons, including PCB can be completely destroyed during normal cement kiln operations, with minimal emissions to the environment. Burning toxic chemical wastes in cement kilns, and other mineral industries, is mutually beneficial to both industry, who generates such wastes, and to society and government, who want to dispose properly of such wastes in a safe, environmentally acceptable manner. The added benefit of energy conservation is important, since large quantities of valuable fuel can be saved in the manufacture of cement when such techniques are employed. (Refs. 16).

  11. 49 CFR 173.172 - Aircraft hydraulic power unit fuel tank.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 2 2011-10-01 2011-10-01 false Aircraft hydraulic power unit fuel tank. 173.172 Section 173.172 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS... Class 1 and Class 7 § 173.172 Aircraft hydraulic power unit fuel tank. Aircraft hydraulic power...

  12. 49 CFR 173.172 - Aircraft hydraulic power unit fuel tank.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 2 2012-10-01 2012-10-01 false Aircraft hydraulic power unit fuel tank. 173.172 Section 173.172 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS... Class 1 and Class 7 § 173.172 Aircraft hydraulic power unit fuel tank. Aircraft hydraulic power...

  13. 49 CFR 173.172 - Aircraft hydraulic power unit fuel tank.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 2 2014-10-01 2014-10-01 false Aircraft hydraulic power unit fuel tank. 173.172 Section 173.172 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS... Class 1 and Class 7 § 173.172 Aircraft hydraulic power unit fuel tank. Aircraft hydraulic power...

  14. 49 CFR 173.172 - Aircraft hydraulic power unit fuel tank.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 2 2013-10-01 2013-10-01 false Aircraft hydraulic power unit fuel tank. 173.172 Section 173.172 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS... Class 1 and Class 7 § 173.172 Aircraft hydraulic power unit fuel tank. Aircraft hydraulic power...

  15. X-38 research aircraft deorbit burn - computer animation

    NASA Technical Reports Server (NTRS)

    1997-01-01

    In the mid-1990's researchers at the NASA Dryden Flight Research Center, Edwards, California, and Johnson Space Center in Houston, Texas, began working actively with the sub-scale X-38 prototype crew return vehicle (CRV). This was an unpiloted lifting body designed at 80 percent of the size of a projected emergency crew return vehicle for the International Space Station. The X-38 and the actual CRV are patterned after a lifting-body shape first employed in the Air Force X-23 (SV-5) program in the mid-1960's and the Air Force-NASA X-24A lifting-body project in the early to mid-1970's. Built by Scaled Composites, Inc., in Mojave, California, and outfitted with avionics, computer systems, and other hardware at Johnson Space Center, two X-38 aircraft were involved in flight research at Dryden beginning in July of 1997. Before that, however, Dryden conducted some 13 flights at a drop zone near California City, California. These tests were done with a 1/6-scale model of the X-38 to test the parafoil concept that would be employed on the X-38 and the actual CRV. The basic concept is that the actual CRV will use an inertial navigation system together with the Global Positioning System of satellites to guide it from the International Space Station into the earth's atmosphere. A deorbit engine module will redirect the vehicle from orbit into the atmosphere where a series of parachutes and a parafoil will deploy in sequence to bring the vehicle to a landing, possibly in a field next to a hospital. Flight research at NASA Dryden for the X-38 began with an unpiloted captive carry flight in which the vehicle remained attached to its future launch vehicle, the Dryden B-52 008. There were four captive flights in 1997 and three in 1998 plus the first drop test on March 12, 1998, using the parachutes and parafoil. Further captive and drop tests occurred in 1999. Although the X-38 landed safely on the lakebed at Edwards after the March 1998 drop test, there had been some problems

  16. Sectoral combustor for burning low-BTU fuel gas

    DOEpatents

    Vogt, Robert L.

    1980-01-01

    A high-temperature combustor for burning low-BTU coal gas in a gas turbine is disclosed. The combustor includes several separately removable combustion chambers each having an annular sectoral cross section and a double-walled construction permitting separation of stresses due to pressure forces and stresses due to thermal effects. Arrangements are described for air-cooling each combustion chamber using countercurrent convective cooling flow between an outer shell wall and an inner liner wall and using film cooling flow through liner panel grooves and along the inner liner wall surface, and for admitting all coolant flow to the gas path within the inner liner wall. Also described are systems for supplying coal gas, combustion air, and dilution air to the combustion zone, and a liquid fuel nozzle for use during low-load operation. The disclosed combustor is fully air-cooled, requires no transition section to interface with a turbine nozzle, and is operable at firing temperatures of up to 3000.degree. F. or within approximately 300.degree. F. of the adiabatic stoichiometric limit of the coal gas used as fuel.

  17. Multi-Fuel Rotary Engine for General Aviation Aircraft

    NASA Technical Reports Server (NTRS)

    Jones, C.; Ellis, D. R.; Meng, P. R.

    1983-01-01

    Design studies, conducted for NASA, of Advanced Multi-fuel General Aviation and Commuter Aircraft Rotary Stratified Charge Engines are summarized. Conceptual design studies of an advanced engine sized to provide 186/250 shaft KW/HP under cruise conditions at 7620/25,000 m/ft. altitude were performed. Relevant engine development background covering both prior and recent engine test results of the direct injected unthrottled rotary engine technology, including the capability to interchangeably operate on gasoline, diesel fuel, kerosene, or aviation jet fuel, are presented and related to growth predictions. Aircraft studies, using these resultant growth engines, define anticipated system effects of the performance and power density improvements for both single engine and twin engine airplanes. The calculated results indicate superior system performance and 30 to 35% fuel economy improvement for the Rotary-engine airplanes as compared to equivalent airframe concept designs with current baseline engines. The research and technology activities required to attain the projected engine performance levels are also discussed.

  18. Lightweight aircraft engines, the potential and problems for use of automotive fuels

    NASA Technical Reports Server (NTRS)

    Patterson, D. J.

    1983-01-01

    A comprehensive data research and analysis for evaluating the use of automotive fuels as a substitute for aviation grade fuel by piston-type general aviation aircraft engines is presented. Historically known problems and potential problems with fuels were reviewed for possible impact relative to application to an aircraft operational environment. This report reviews areas such as: fuel specification requirements, combustion knock, preignition, vapor lock, spark plug fouling, additives for fuel and oil, and storage stability.

  19. Clean-Burning Fuel for Use in Woodstoves: Feminist Politics, Community Development and Global Sustainability.

    ERIC Educational Resources Information Center

    Grace, Victoria; Arnoux, Louis

    1998-01-01

    Rural women in less-developed nations use fuels that can be toxic and are becoming scarce. Feminist, sociological, and community-development issues were involved in the process of introducing clear-burning fuel, enabling a focus on both the effects on the health of fuel users and concern for ecological sustainability. (SK)

  20. The use of hydrogen for aircraft propulsion in view of the fuel crisis.

    NASA Technical Reports Server (NTRS)

    Weiss, S.

    1973-01-01

    In view of projected decreases in available petroleum fuels, interest has been generated in exploiting the potential of liquid hydrogen (LH2) as an aircraft fuel. Cost studies of LH2 production show it to be more expensive than presently used fuels. Regardless of cost considerations, LH2 is viewed as an attractive aircraft fuel because of the potential performance benefits it offers. Accompanying these benefits, however, are many new problems associated with aircraft design and operations; for example, problems related to fuel system design and the handling of LH2 during ground servicing. Some of the factors influencing LH2 fuel tank design, pumping, heat exchange, and flow regulation are discussed.

  1. Reductions in aircraft particulate emissions due to the use of Fischer-Tropsch fuels

    NASA Astrophysics Data System (ADS)

    Beyersdorf, A. J.; Timko, M. T.; Ziemba, L. D.; Bulzan, D.; Corporan, E.; Herndon, S. C.; Howard, R.; Miake-Lye, R.; Thornhill, K. L.; Winstead, E.; Wey, C.; Yu, Z.; Anderson, B. E.

    2014-01-01

    The use of alternative fuels for aviation is likely to increase due to concerns over fuel security, price stability, and the sustainability of fuel sources. Concurrent reductions in particulate emissions from these alternative fuels are expected because of changes in fuel composition including reduced sulfur and aromatic content. The NASA Alternative Aviation Fuel Experiment (AAFEX) was conducted in January-February 2009 to investigate the effects of synthetic fuels on gas-phase and particulate emissions. Standard petroleum JP-8 fuel, pure synthetic fuels produced from natural gas and coal feedstocks using the Fischer-Tropsch (FT) process, and 50% blends of both fuels were tested in the CFM-56 engines on a DC-8 aircraft. To examine plume chemistry and particle evolution with time, samples were drawn from inlet probes positioned 1, 30, and 145 m downstream of the aircraft engines. No significant alteration to engine performance was measured when burning the alternative fuels. However, leaks in the aircraft fuel system were detected when operated with the pure FT fuels as a result of the absence of aromatic compounds in the fuel. Dramatic reductions in soot emissions were measured for both the pure FT fuels (reductions in mass of 86% averaged over all powers) and blended fuels (66%) relative to the JP-8 baseline with the largest reductions at idle conditions. At 7% power, this corresponds to a reduction from 7.6 mg kg-1 for JP-8 to 1.2 mg kg-1 for the natural gas FT fuel. At full power, soot emissions were reduced from 103 to 24 mg kg-1 (JP-8 and natural gas FT, respectively). The alternative fuels also produced smaller soot (e.g., at 85% power, volume mean diameters were reduced from 78 nm for JP-8 to 51 nm for the natural gas FT fuel), which may reduce their ability to act as cloud condensation nuclei (CCN). The reductions in particulate emissions are expected for all alternative fuels with similar reductions in fuel sulfur and aromatic content regardless of the

  2. Charring temperatures are driven by the fuel types burned in a peatland wildfire

    PubMed Central

    Hudspith, Victoria A.; Belcher, Claire M.; Yearsley, Jonathan M.

    2014-01-01

    Peatlands represent a globally important carbon store; however, the human exploitation of this ecosystem is increasing both the frequency and severity of fires on drained peatlands. Yet, the interactions between the hydrological conditions (ecotopes), the fuel types being burned, the burn severity, and the charring temperatures (pyrolysis intensity) remain poorly understood. Here we present a post-burn assessment of a fire on a lowland raised bog in Co. Offaly, Ireland (All Saints Bog). Three burn severities were identified in the field (light, moderate, and deeply burned), and surface charcoals were taken from 17 sites across all burn severities. Charcoals were classified into two fuel type categories (either ground or aboveground fuel) and the reflectance of each charcoal particle was measured under oil using reflectance microscopy. Charcoal reflectance shows a positive relationship with charring temperature and as such can be used as a temperature proxy to reconstruct minimum charring temperatures after a fire event. Resulting median reflectance values for ground fuels are 1.09 ± 0.32%Romedian, corresponding to estimated minimum charring temperatures of 447°C ± 49°C. In contrast, the median charring temperatures of aboveground fuels were found to be considerably higher, 646°C ± 73°C (3.58 ± 0.77%Romedian). A mixed-effects modeling approach was used to demonstrate that the interaction effects of burn severity, as well as ecotope classes, on the charcoal reflectance is small compared to the main effect of fuel type. Our findings reveal that the different fuel types on raised bogs are capable of charring at different temperatures within the same fire, and that the pyrolysis intensity of the fire on All Saints Bog was primarily driven by the fuel types burning, with only a weak association to the burn severity or ecotope classes. PMID:25566288

  3. Monte Carlo Simulation of the TRIGA Mark II Benchmark Experiment with Burned Fuel

    SciTech Connect

    Jeraj, Robert; Zagar, Tomaz; Ravnik, Matjaz

    2002-03-15

    Monte Carlo calculations of a criticality experiment with burned fuel on the TRIGA Mark II research reactor are presented. The main objective was to incorporate burned fuel composition calculated with the WIMSD4 deterministic code into the MCNP4B Monte Carlo code and compare the calculated k{sub eff} with the measurements. The criticality experiment was performed in 1998 at the ''Jozef Stefan'' Institute TRIGA Mark II reactor in Ljubljana, Slovenia, with the same fuel elements and loading pattern as in the TRIGA criticality benchmark experiment with fresh fuel performed in 1991. The only difference was that in 1998, the fuel elements had on average burnup of {approx}3%, corresponding to 1.3-MWd energy produced in the core in the period between 1991 and 1998. The fuel element burnup accumulated during 1991-1998 was calculated with the TRIGLAV in-house-developed fuel management two-dimensional multigroup diffusion code. The burned fuel isotopic composition was calculated with the WIMSD4 code and compared to the ORIGEN2 calculations. Extensive comparison of burned fuel material composition was performed for both codes for burnups up to 20% burned {sup 235}U, and the differences were evaluated in terms of reactivity. The WIMSD4 and ORIGEN2 results agreed well for all isotopes important in reactivity calculations, giving increased confidence in the WIMSD4 calculation of the burned fuel material composition. The k{sub eff} calculated with the combined WIMSD4 and MCNP4B calculations showed good agreement with the experimental values. This shows that linking of WIMSD4 with MCNP4B for criticality calculations with burned fuel is feasible and gives reliable results.

  4. Vegetation structure and fire weather influence variation in burn severity and fuel consumption during peatland wildfires

    NASA Astrophysics Data System (ADS)

    Davies, G. M.; Domènech, R.; Gray, A.; Johnson, P. C. D.

    2015-09-01

    Temperate peatland wildfires are of significant environmental concern but information on their environmental effects is lacking. We assessed variation in burn severity and fuel consumption within and between wildfires that burnt British moorlands in 2011 and 2012. We adapted the Composite Burn Index (pCBI) to provide semi-quantitative estimates of burn severity. Pre- and post-fire surface (shrubs and graminoids) and ground (litter, moss, duff) fuel loads associated with large wildfires were assessed using destructive sampling and analysed using a Generalised Linear Mixed Model (GLMM). Consumption during wildfires was compared with published estimates of consumption during prescribed burns. Burn severity and fuel consumption were related to fire weather, assessed using the Canadian Fire Weather Index System (FWI System), and pre-fire fuel structure. pCBI varied 1.6 fold between, and up to 1.7 fold within, wildfires. pCBI was higher where moisture codes of the FWI System indicated drier fuels. Spatial variation in pre- and post-fire fuel load accounted for a substantial proportion of the variance in fuel loads. Average surface fuel consumption was a linear function of pre-fire fuel load. Average ground fuel combustion completeness could be predicted by the Buildup Index. Carbon release ranged between 0.36 and 1.00 kg C m-2. The flammability of ground fuel layers may explain the higher C release-rates seen for wildfires in comparison to prescribed burns. Drier moorland community types appear to be at greater risk of severe burns than blanket-bog communities.

  5. Biomass burning fuel consumption dynamics in the tropics and subtropics assessed from satellite

    NASA Astrophysics Data System (ADS)

    Andela, Niels; van der Werf, Guido R.; Kaiser, Johannes W.; van Leeuwen, Thijs T.; Wooster, Martin J.; Lehmann, Caroline E. R.

    2016-06-01

    Landscape fires occur on a large scale in (sub)tropical savannas and grasslands, affecting ecosystem dynamics, regional air quality and concentrations of atmospheric trace gasses. Fuel consumption per unit of area burned is an important but poorly constrained parameter in fire emission modelling. We combined satellite-derived burned area with fire radiative power (FRP) data to derive fuel consumption estimates for land cover types with low tree cover in South America, Sub-Saharan Africa, and Australia. We developed a new approach to estimate fuel consumption, based on FRP data from the polar-orbiting Moderate Resolution Imaging Spectroradiometer (MODIS) and the geostationary Spinning Enhanced Visible and Infrared Imager (SEVIRI) in combination with MODIS burned-area estimates. The fuel consumption estimates based on the geostationary and polar-orbiting instruments showed good agreement in terms of spatial patterns. We used field measurements of fuel consumption to constrain our results, but the large variation in fuel consumption in both space and time complicated this comparison and absolute fuel consumption estimates remained more uncertain. Spatial patterns in fuel consumption could be partly explained by vegetation productivity and fire return periods. In South America, most fires occurred in savannas with relatively long fire return periods, resulting in comparatively high fuel consumption as opposed to the more frequently burning savannas in Sub-Saharan Africa. Strikingly, we found the infrequently burning interior of Australia to have higher fuel consumption than the more productive but frequently burning savannas in northern Australia. Vegetation type also played an important role in explaining the distribution of fuel consumption, by affecting both fuel build-up rates and fire return periods. Hummock grasslands, which were responsible for a large share of Australian biomass burning, showed larger fuel build-up rates than equally productive grasslands in

  6. A methanol/oxygen burning combustor for an aircraft auxiliary emergency power unit

    SciTech Connect

    Carr, E.; Todd, H. , Burnley, Lancashire )

    1989-01-01

    The development of advanced single-engine aircraft with reduced stability and Fly-by-Wire control systems requires the provision of emergency hydraulic and electrical power from a stored energy system. The desire to achieve this objective using readily available fluids of low toxicity has led to the development of a methanol/oxygen burning combustor to provide a hot gas stream to drive a small turbine. The paper describes the performance of a 300 kW output combustor, which is cooled by the methanol consumed.

  7. Technical Development on Burn-up Credit for Spent LWR Fuel

    SciTech Connect

    Gauld, I.C.

    2001-12-26

    Technical development on burn-up credit for spent LWR fuels had been performed at JAERI since 1990 under the contract with Science and Technology Agency of Japan entitled ''Technical Development on Criticality Safety Management for Spent LWR Fuels.'' Main purposes of this work are to obtain the experimental data on criticality properties and isotopic compositions of spent LWR fuels and to verify burnup and criticality calculation codes. In this work three major experiments of exponential experiments for spent fuel assemblies to obtain criticality data, non-destructive gamma-ray measurement of spent fuel rods for evaluating axial burn-up profiles, and destructive analyses of spent fuel samples for determining precise burn-up and isotopic compositions were carried out. The measured data obtained were used for validating calculation codes as well as an examination of criticality safety analyses. Details of the work are described in this report.

  8. Global combustion: the connection between fossil fuel and biomass burning emissions (1997-2010).

    PubMed

    Balch, Jennifer K; Nagy, R Chelsea; Archibald, Sally; Bowman, David M J S; Moritz, Max A; Roos, Christopher I; Scott, Andrew C; Williamson, Grant J

    2016-06-05

    Humans use combustion for heating and cooking, managing lands, and, more recently, for fuelling the industrial economy. As a shift to fossil-fuel-based energy occurs, we expect that anthropogenic biomass burning in open landscapes will decline as it becomes less fundamental to energy acquisition and livelihoods. Using global data on both fossil fuel and biomass burning emissions, we tested this relationship over a 14 year period (1997-2010). The global average annual carbon emissions from biomass burning during this time were 2.2 Pg C per year (±0.3 s.d.), approximately one-third of fossil fuel emissions over the same period (7.3 Pg C, ±0.8 s.d.). There was a significant inverse relationship between average annual fossil fuel and biomass burning emissions. Fossil fuel emissions explained 8% of the variation in biomass burning emissions at a global scale, but this varied substantially by land cover. For example, fossil fuel burning explained 31% of the variation in biomass burning in woody savannas, but was a non-significant predictor for evergreen needleleaf forests. In the land covers most dominated by human use, croplands and urban areas, fossil fuel emissions were more than 30- and 500-fold greater than biomass burning emissions. This relationship suggests that combustion practices may be shifting from open landscape burning to contained combustion for industrial purposes, and highlights the need to take into account how humans appropriate combustion in global modelling of contemporary fire. Industrialized combustion is not only an important driver of atmospheric change, but also an important driver of landscape change through companion declines in human-started fires.This article is part of the themed issue 'The interaction of fire and mankind'.

  9. Vegetation structure and fire weather influence variation in burn severity and fuel consumption during peatland wildfires

    NASA Astrophysics Data System (ADS)

    Davies, G. M.; Domènech, R.; Gray, A.; Johnson, P. C. D.

    2016-01-01

    Temperate peatland wildfires are of significant environmental concern but information on their environmental effects is lacking. We assessed variation in burn severity and fuel consumption within and between wildfires that burnt British moorlands in 2011 and 2012. We adapted the composite burn index (pCBI) to provide semi-quantitative estimates of burn severity. Pre- and post-fire surface (shrubs and graminoids) and ground (litter, moss, duff) fuel loads associated with large wildfires were assessed using destructive sampling and analysed using a generalised linear mixed model (GLMM). Consumption during wildfires was compared with published estimates of consumption during prescribed burns. Burn severity and fuel consumption were related to fire weather, assessed using the Canadian Fire Weather Index System (FWI System), and pre-fire vegetation type. pCBI varied 1.6 fold between, and up to 1.7 fold within, wildfires. pCBI was higher where moisture codes of the FWI System indicated drier fuels. Spatial variation in pre- and post-fire fuel load accounted for a substantial proportion of the variance in fuel loads. Average surface fuel consumption was a linear function of pre-fire fuel load. Average ground fuel combustion completeness could be predicted by the Buildup Index. Carbon release ranged between 0.36 and 1.00 kg C m-2. The flammability of ground fuel layers may explain the higher C release-rates seen for wildfires in comparison to prescribed burns. Drier moorland community types appear to be at greater risk of severe burns than blanket-bog communities.

  10. Fuel dispersal modeling for aircraft-runway impact scenarios

    SciTech Connect

    Tieszen, S.R.

    1995-11-01

    A fuel dispersal model for C-141 transport accidents was developed for the Defense Nuclear Agency`s Fuel Fire Technology Base Program to support Weapon System Safety Assessments. The spectrum of accidents resulting from aircraft impact on a runway was divided into three fuel dispersal regimes: low, intermediate, and high-velocity impact. Sufficient data existed in the accident, crash test, and fuel-filled bomb literature to support development of a qualitative framework for dispersal models, but not quantitative models for all regimes. Therefore, a test series at intermediate scale was conducted to generate data on which to base the model for the high-velocity regime. Tests were conducted over an impact velocity range from 12 m/s to 91 m/s and angles of impact from 22.5{degrees} to 67.5{degrees}. Dependent variables were area covered by dispersed fuel, amount of mass in that area, and location of the area relative to the impact line. Test results showed that no liquid pooling occurred for impact velocities greater than 61 m/s, independent of the angle of impact. Some pooling did occur at lower velocities, but in no test was the liquid-layer thickness greater than 5.25 mm.

  11. Modeling, design and energy management of fuel cell systems for aircraft

    NASA Astrophysics Data System (ADS)

    Bradley, Thomas Heenan

    Fuel cell powered aircraft have been of long term interest to the aviation community because of their potential for improved performance and environmental compatibility. Only recently have improvements in the technological readiness of fuel cell powerplants enabled the first aviation applications of fuel cell technology. Based on the results of conceptual design studies and a few technology demonstration projects, there has emerged a widespread understanding of the importance of fuel cell powerplants for near-term and future aviation applications. Despite this, many aspects of the performance, design and construction of robust and optimized fuel cell powered aircraft have not been fully explored. This goal of this research then is to develop an improved understanding of the performance, design characteristics, design tradeoffs and viability of fuel cell powerplants for aviation applications. To accomplish these goals, new modeling, design, and experimental tools are developed, validated and applied to the design of fuel cell powered unmanned aerial vehicles. First, a general sub-system model of fuel cell powerplant performance, mass and geometry is derived from experimental and theoretical investigations of a fuel cell powerplant that is developed in hardware. These validated fuel cell subsystem models are then incorporated into a computer-based, application-integrated, parametric, and optimizeable design environment that allows for the concurrent design of the aircraft and fuel cell powerplant. The advanced modeling and design techniques required for modern aircraft design (including multi-disciplinary analysis, performance optimization under uncertainty and system performance validation), are applied at the fuel cell subsystem level and are linked to aircraft performance and design metrics. These tools and methods are then applied to the analysis and design of fuel cell powered aircraft in a series of case studies and design experiments. Based on the results of

  12. Aircraft

    DOEpatents

    Hibbs, B.D.; Lissaman, P.B.S.; Morgan, W.R.; Radkey, R.L.

    1998-09-22

    This disclosure provides a solar rechargeable aircraft that is inexpensive to produce, is steerable, and can remain airborne almost indefinitely. The preferred aircraft is a span-loaded flying wing, having no fuselage or rudder. Travelling at relatively slow speeds, and having a two-hundred foot wingspan that mounts photovoltaic cells on most all of the wing`s top surface, the aircraft uses only differential thrust of its eight propellers to turn. Each of five sections of the wing has one or more engines and photovoltaic arrays, and produces its own lift independent of the other sections, to avoid loading them. Five two-sided photovoltaic arrays, in all, are mounted on the wing, and receive photovoltaic energy both incident on top of the wing, and which is incident also from below, through a bottom, transparent surface. The aircraft is capable of a top speed of about ninety miles per hour, which enables the aircraft to attain and can continuously maintain altitudes of up to sixty-five thousand feet. Regenerative fuel cells in the wing store excess electricity for use at night, such that the aircraft can sustain its elevation indefinitely. A main spar of the wing doubles as a pressure vessel that houses hydrogen and oxygen gases for use in the regenerative fuel cell. The aircraft has a wide variety of applications, which include weather monitoring and atmospheric testing, communications, surveillance, and other applications as well. 31 figs.

  13. Aircraft

    DOEpatents

    Hibbs, Bart D.; Lissaman, Peter B. S.; Morgan, Walter R.; Radkey, Robert L.

    1998-01-01

    This disclosure provides a solar rechargeable aircraft that is inexpensive to produce, is steerable, and can remain airborne almost indefinitely. The preferred aircraft is a span-loaded flying wing, having no fuselage or rudder. Travelling at relatively slow speeds, and having a two-hundred foot wingspan that mounts photovoltaic cells on most all of the wing's top surface, the aircraft uses only differential thrust of its eight propellers to turn. Each of five sections of the wing has one or more engines and photovoltaic arrays, and produces its own lift independent of the other sections, to avoid loading them. Five two-sided photovoltaic arrays, in all, are mounted on the wing, and receive photovoltaic energy both incident on top of the wing, and which is incident also from below, through a bottom, transparent surface. The aircraft is capable of a top speed of about ninety miles per hour, which enables the aircraft to attain and can continuously maintain altitudes of up to sixty-five thousand feet. Regenerative fuel cells in the wing store excess electricity for use at night, such that the aircraft can sustain its elevation indefinitely. A main spar of the wing doubles as a pressure vessel that houses hydrogen and oxygen gasses for use in the regenerative fuel cell. The aircraft has a wide variety of applications, which include weather monitoring and atmospheric testing, communications, surveillance, and other applications as well.

  14. An assessment of the crash fire hazard of liquid hydrogen fueled aircraft

    NASA Technical Reports Server (NTRS)

    1982-01-01

    The crash fire hazards of liquid hydrogen fueled aircraft relative to those of mission equivalent aircraft fueled either with conventional fuel or with liquefied methane were evaluated. The aircraft evaluated were based on Lockheed Corporation design for 400 passenger, Mach 0.85, 5500 n. mile aircraft. Four crash scenarios were considered ranging from a minor incident causing some loss of fuel system integrity to a catastrophic crash. Major tasks included a review of hazardous properties of the alternate fuels and of historic crash fire data; a comparative hazard evluation for each of the three fuels under four crash scenarios a comprehensive review and analysis and an identification of areas further development work. The conclusion was that the crash fire hazards are not significantly different when compared in general for the three fuels, although some fuels showed minor advantages in one respect or another.

  15. Study of Hydrogen Recovery Systems for Gas Vented While Refueling Liquid-Hydrogen Fueled Aircraft

    NASA Technical Reports Server (NTRS)

    Baker, C. R.

    1979-01-01

    Methods of capturing and reliquefying the cold hydrogen vapor produced during the fueling of aircraft designed to utilize liquid hydrogen fuel were investigated. An assessment of the most practical, economic, and energy efficient of the hydrogen recovery methods is provided.

  16. Design and evaluation of aircraft heat source systems for use with high-freezing point fuels

    NASA Technical Reports Server (NTRS)

    Pasion, A. J.

    1979-01-01

    The objectives were the design, performance and economic analyses of practical aircraft fuel heating systems that would permit the use of high freezing-point fuels on long-range aircraft. Two hypothetical hydrocarbon fuels with freezing points of -29 C and -18 C were used to represent the variation from current day jet fuels. A Boeing 747-200 with JT9D-7/7A engines was used as the baseline aircraft. A 9300 Km mission was used as the mission length from which the heat requirements to maintain the fuel above its freezing point was based.

  17. Commercial Aircraft Emission Scenario for 2020: Database Development and Analysis

    NASA Technical Reports Server (NTRS)

    Sutkus, Donald J., Jr.; Baughcum, Steven L.; DuBois, Douglas P.; Wey, Chowen C. (Technical Monitor)

    2003-01-01

    This report describes the development of a three-dimensional database of aircraft fuel use and emissions (NO(x), CO, and hydrocarbons) for the commercial aircraft fleet projected to 2020. Global totals of emissions and fuel burn for 2020 are compared to global totals from previous aircraft emission scenario calculations.

  18. Apparatus and method for burning a lean, premixed fuel/air mixture with low NOx emission

    DOEpatents

    Kostiuk, Larry W.; Cheng, Robert K.

    1996-01-01

    An apparatus for enabling a burner to stably burn a lean fuel/air mixture. The burner directs the lean fuel/air mixture in a stream. The apparatus comprises an annular flame stabilizer; and a device for mounting the flame stabilizer in the fuel/air mixture stream. The burner may include a body having an internal bore, in which case, the annular flame stabilizer is shaped to conform to the cross-sectional shape of the bore, is spaced from the bore by a distance greater than about 0.5 mm, and the mounting device mounts the flame stabilizer in the bore. An apparatus for burning a gaseous fuel with low NOx emissions comprises a device for premixing air with the fuel to provide a lean fuel/air mixture; a nozzle having an internal bore through which the lean fuel/air mixture passes in a stream; and a flame stabilizer mounted in the stream of the lean fuel/air mixture. The flame stabilizer may be mounted in the internal bore, in which case, it is shaped and is spaced from the bore as just described. In a method of burning a lean fuel/air mixture, a lean fuel/air mixture is provided, and is directed in a stream; an annular eddy is created in the stream of the lean fuel/air mixture; and the lean fuel/air mixture is ignited at the eddy.

  19. The thermal efficiency and cost of producing hydrogen and other synthetic aircraft fuels from coal

    NASA Technical Reports Server (NTRS)

    Witcofski, R. D.

    1977-01-01

    A comparison is made of the cost and thermal efficiency of producing liquid hydrogen, liquid methane and synthetic aviation kerosene from coal. These results are combined with estimates of the cost and energy losses associated with transporting, storing, and transferring the fuels to aircraft. The results of hydrogen-fueled and kerosene-fueled aircraft performance studies are utilized to compare the economic viability and efficiency of coal resource utilization of synthetic aviation fuels.

  20. The thermal efficiency and cost of producing hydrogen and other synthetic aircraft fuels from coal

    NASA Technical Reports Server (NTRS)

    Witcofski, R. D.

    1976-01-01

    A comparison is made of the cost and thermal efficiency of producing liquid hydrogen, liquid methane and synthetic aviation kerosene from coal. These results are combined with estimates of the cost and energy losses associated with transporting, storing, and transferring the fuels to aircraft. The results of hydrogen-fueled and kerosene-fueled aircraft performance studies are utilized to compare the economic viability and efficiency of coal resource utilization of synthetic aviation fuels.

  1. Method and apparatus for controlling fuel/air mixture in a lean burn engine

    DOEpatents

    Kubesh, John Thomas; Dodge, Lee Gene; Podnar, Daniel James

    1998-04-07

    The system for controlling the fuel/air mixture supplied to a lean burn engine when operating on natural gas, gasoline, hydrogen, alcohol, propane, butane, diesel or any other fuel as desired. As specific humidity of air supplied to the lean burn engine increases, the oxygen concentration of exhaust gas discharged by the engine for a given equivalence ratio will decrease. Closed loop fuel control systems typically attempt to maintain a constant exhaust gas oxygen concentration. Therefore, the decrease in the exhaust gas oxygen concentration resulting from increased specific humidity will often be improperly attributed to an excessive supply of fuel and the control system will incorrectly reduce the amount of fuel supplied to the engine. Also, the minimum fuel/air equivalence ratio for a lean burn engine to avoid misfiring will increase as specific humidity increases. A relative humidity sensor to allow the control system to provide a more enriched fuel/air mixture at high specific humidity levels. The level of specific humidity may be used to compensate an output signal from a universal exhaust gas oxygen sensor for changing oxygen concentrations at a desired equivalence ratio due to variation in specific humidity specific humidity. As a result, the control system will maintain the desired efficiency, low exhaust emissions and power level for the associated lean burn engine regardless of the specific humidity level of intake air supplied to the lean burn engine.

  2. Modeling of gas turbine - solid oxide fuel cell systems for combined propulsion and power on aircraft

    NASA Astrophysics Data System (ADS)

    Waters, Daniel Francis

    This dissertation investigates the use of gas turbine (GT) engine integrated solid oxide fuel cells (SOFCs) to reduce fuel burn in aircraft with large electrical loads like sensor-laden unmanned air vehicles (UAVs). The concept offers a number of advantages: the GT absorbs many SOFC balance of plant functions (supplying fuel, air, and heat to the fuel cell) thereby reducing the number of components in the system; the GT supplies fuel and pressurized air that significantly increases SOFC performance; heat and unreacted fuel from the SOFC are recaptured by the GT cycle offsetting system-level losses; good transient response of the GT cycle compensates for poor transient response of the SOFC. The net result is a system that can supply more electrical power more efficiently than comparable engine-generator systems with only modest (<10%) decrease in power density. Thermodynamic models of SOFCs, catalytic partial oxidation (CPOx) reactors, and three GT engine types (turbojet, combined exhaust turbofan, separate exhaust turbofan) are developed that account for equilibrium gas phase and electrochemical reaction, pressure losses, and heat losses in ways that capture `down-the-channel' effects (a level of fidelity necessary for making meaningful performance, mass, and volume estimates). Models are created in a NASA-developed environment called Numerical Propulsion System Simulation (NPSS). A sensitivity analysis identifies important design parameters and translates uncertainties in model parameters into uncertainties in overall performance. GT-SOFC integrations reduce fuel burn 3-4% in 50 kW systems on 35 kN rated engines (all types) with overall uncertainty <1%. Reductions of 15-20% are possible at the 200 kW power level. GT-SOFCs are also able to provide more electric power (factors >3 in some cases) than generator-based systems before encountering turbine inlet temperature limits. Aerodynamic drag effects of engine-airframe integration are by far the most important

  3. Energy efficient engine program contributions to aircraft fuel conservation

    NASA Technical Reports Server (NTRS)

    Batterton, P. G.

    1984-01-01

    Significant advances in high bypass turbofan technologies that enhance fuel efficiency have been demonstrated in the NASA Energy Efficient Engine Program. This highly successful second propulsion element of the NASA Aircraft Energy Efficiency Program included major contract efforts with both General Electric and Pratt & Whitney. Major results of these efforts will be presented including highlights from the NASA/General Electric E3 research turbofan engine test. Direct application of all the E3 technologies could result in fuel savings of over 18% compared to the CF6-50 and JT9D-7. Application of the E3 technologies to new and derivative engines such as the CF6-80C and PW 2037, as well as others, will be discussed. Significant portions of the fuel savings benefit for these new products can be directly related to the E3 technology program. Finally, results of a study looking at far term advanced turbofan engines will be briefly described. The study shows that substantial additional fuel savings over E3 are possible with additional turbofan technology programs.

  4. Study of the application of hydrogen fuel to long-range subsonic transport aircraft, volume 2

    NASA Technical Reports Server (NTRS)

    Brewer, G. D.; Morris, R. E.; Lange, R. H.; Moore, J. W.

    1975-01-01

    The feasibility, practicability, and potential advantages/disadvantages of using liquid hydrogen as fuel in long range, subsonic transport aircraft of advanced design were studied. Both passenger and cargo-type aircraft were investigated. To provide a valid basis for comparison, conventional hydrocarbon (Jet A) fueled aircraft were designed to perform identical missions using the same advanced technology and meeting the same operational constraints. The liquid hydrogen and Jet A fueled aircraft were compared on the basis of weight, size, energy utilization, cost, noise, emissions, safety, and operational characteristics. A program of technology development was formulated.

  5. Challenge to Aviation: Hatching a Leaner Pterosauer. [Improving Commercial Aircraft Design for Greater Fuel Efficiency

    NASA Technical Reports Server (NTRS)

    Moss, F. E.

    1975-01-01

    Modifications in commercial aircraft design, particularly the development of lighter aircraft, are discussed as effective means of reducing aviation fuel consumption. The modifications outlined include: (1) use of the supercritical wing; (2) generation of the winglet; (3) production and flight testing of composite materials; and, (4) implementation of fly-by-wire control systems. Attention is also given to engineering laminar air flow control, improving cargo payloads, and adapting hydrogen fuels for aircraft use.

  6. Temperature of aircraft cargo flame exposure during accidents involving fuel spills

    SciTech Connect

    Mansfield, J.A.

    1993-01-01

    This report describes an evaluation of flame exposure temperatures of weapons contained in alert (parked) bombers due to accidents that involve aircraft fuel fires. The evaluation includes two types of accident, collisions into an alert aircraft by an aircraft that is on landing or take-off, and engine start accidents. Both the B-1B and B-52 alert aircraft are included in the evaluation.

  7. Microstructural modeling of thermal conductivity of high burn-up mixed oxide fuel

    NASA Astrophysics Data System (ADS)

    Teague, Melissa; Tonks, Michael; Novascone, Stephen; Hayes, Steven

    2014-01-01

    Predicting the thermal conductivity of oxide fuels as a function of burn-up and temperature is fundamental to the efficient and safe operation of nuclear reactors. However, modeling the thermal conductivity of fuel is greatly complicated by the radially inhomogeneous nature of irradiated fuel in both composition and microstructure. In this work, radially and temperature-dependent models for effective thermal conductivity were developed utilizing optical micrographs of high burn-up mixed oxide fuel. The micrographs were employed to create finite element meshes with the OOF2 software. The meshes were then used to calculate the effective thermal conductivity of the microstructures using the BISON [1] fuel performance code. The new thermal conductivity models were used to calculate thermal profiles at end of life for the fuel pellets. These results were compared to thermal conductivity models from the literature, and comparison between the new finite element-based thermal conductivity model and the Duriez-Lucuta model was favorable.

  8. Microstructural Modeling of Thermal Conductivity of High Burn-up Mixed Oxide Fuel

    SciTech Connect

    Melissa Teague; Michael Tonks; Stephen Novascone; Steven Hayes

    2014-01-01

    Predicting the thermal conductivity of oxide fuels as a function of burn-up and temperature is fundamental to the efficient and safe operation of nuclear reactors. However, modeling the thermal conductivity of fuel is greatly complicated by the radially inhomogeneous nature of irradiated fuel in both composition and microstructure. In this work, radially and temperature-dependent models for effective thermal conductivity were developed utilizing optical micrographs of high burn-up mixed oxide fuel. The micrographs were employed to create finite element meshes with the OOF2 software. The meshes were then used to calculate the effective thermal conductivity of the microstructures using the BISON fuel performance code. The new thermal conductivity models were used to calculate thermal profiles at end of life for the fuel pellets. These results were compared to thermal conductivity models from the literature, and comparison between the new finite element-based thermal conductivity model and the Duriez–Lucuta model was favorable.

  9. In-flight and simulated aircraft fuel temperature measurements

    NASA Technical Reports Server (NTRS)

    Svehla, Roger A.

    1990-01-01

    Fuel tank measurements from ten flights of an L1011 commercial aircraft are reported for the first time. The flights were conducted from 1981 to 1983. A thermocouple rake was installed in an inboard wing tank and another in an outboard tank. During the test periods of either 2 or 5 hr, at altitudes of 10,700 m (35,000 ft) or higher, either the inboard or the outboard tank remained full. Fuel temperature profiles generally developed in the expected manner. The bulk fuel was mixed by natural convection to a nearly uniform temperature, especially in the outboard tank, and a gradient existed at the bottom conduction zone. The data indicated that when full, the upper surface of the inboard tank was wetted and the outboard tank was unwetted. Companion NASA Lewis Research Center tests were conducted in a 0.20 cubic meter (52 gal) tank simulator of the outboard tank, chilled on the top and bottom, and insulated on the sides. Even though the simulator tank had no internal components corresponding to the wing tank, temperatures agreed with the flight measurements for wetted upper surface conditions, but not for unwetted conditions. It was concluded that if boundary conditions are carefully controlled, simulators are a useful way of evaluating actual flight temperatures.

  10. The use of hydrogen for aircraft propulsion in view of the fuel crisis

    NASA Technical Reports Server (NTRS)

    Weiss, S.

    1973-01-01

    Some factors influencing the technical feasibility of operating a liquid hydrogen-fueled airplane are discussed in light of the projected decrease of fossil fuels. Other sources of energy, such as wind, tidal, solar, and geothermal, are briefly mentioned. In view of projected decreases in available petroleum fuels, interest has been generated in exploiting the potential of liquid hydrogen (LH2) as an aircraft fuel. Cost studies of LH2 production show it to be more expensive than presently used fuels. Regardless of cost considerations, LH2 is viewed as an attractive aircraft fuel because of the potential performance benefits it offers. Accompanying these benefits, however, are many new problems associated with aircraft design and operations; for example, problems related to fuel system design and the handling of LH2 during ground servicing. Some of the factors influencing LH2 fuel tank design, pumping, heat exchange, and flow regulation are discussed.

  11. Burns

    MedlinePlus

    ... if signs of infection develop. These signs include: Drainage or pus from the burned skin Fever Increased pain Red streaks spreading from the burn Swollen lymph nodes Also call a provider right away if ...

  12. Emission factors from residential combustion appliances burning Portuguese biomass fuels.

    PubMed

    Fernandes, A P; Alves, C A; Gonçalves, C; Tarelho, L; Pio, C; Schimdl, C; Bauer, H

    2011-11-01

    Smoke from residential wood burning has been identified as a major contributor to air pollution, motivating detailed emission measurements under controlled conditions. A series of experiments were performed to compare the emission levels from two types of wood-stoves to those of fireplaces. Eight types of biomass were burned in the laboratory: wood from seven species of trees grown in the Portuguese forest (Pinus pinaster, Eucalyptus globulus, Quercus suber, Acacia longifolia, Quercus faginea, Olea europaea and Quercus ilex rotundifolia) and briquettes produced from forest biomass waste. Average emission factors were in the ranges 27.5-99.2 g CO kg(-1), 552-1660 g CO(2) kg(-1), 0.66-1.34 g NO kg(-1), and 0.82-4.94 g hydrocarbons kg(-1) of biomass burned (dry basis). Average particle emission factors varied between 1.12 and 20.06 g kg(-1) biomass burned (dry basis), with higher burn rates producing significantly less particle mass per kg wood burned than the low burn rates. Particle mass emission factors from wood-stoves were lower than those from the fireplace. The average emission factors for organic and elemental carbon were in the intervals 0.24-10.1 and 0.18-0.68 g kg(-1) biomass burned (dry basis), respectively. The elemental carbon content of particles emitted from the energy-efficient "chimney type" logwood stove was substantially higher than in the conventional cast iron stove and fireplace, whereas the opposite was observed for the organic carbon fraction. Pinus pinaster, the only softwood species among all, was the biofuel with the lowest emissions of particles, CO, NO and hydrocarbons.

  13. Metallic inert matrix fuel concept for minor actinides incineration to achieve ultra-high burn-up

    NASA Astrophysics Data System (ADS)

    Lipkina, K.; Savchenko, A.; Skupov, M.; Glushenkov, A.; Vatulin, A.; Uferov, O.; Ivanov, Y.; Kulakov, G.; Ershov, S.; Maranchak, S.; Kozlov, A.; Maynikov, E.; Konova, K.

    2014-09-01

    The advantages of using Inert Matrix Fuel (IMF) in a design of an isolated arrangement of fuel are considered, with emphasis on, low temperatures in the fuel center, achievement of high burn-ups, and an environment friendly process for the fuel element fabrication. Changes in the currently existing concept of IMF usage are suggested, involving novel IMF design in the nuclear fuel cycle.

  14. Multi-fuel rotary engine for general aviation aircraft

    NASA Technical Reports Server (NTRS)

    Jones, C.; Ellis, D. R.; Meng, P. R.

    1983-01-01

    Design studies of advanced multifuel general aviation and commuter aircraft rotary stratified charge engines are summarized. Conceptual design studies were performed at two levels of technology, on advanced general aviation engines sized to provide 186/250 shaft kW/hp under cruise conditions at 7620 (25000 m/ft) altitude. A follow on study extended the results to larger (2500 hp max.) engine sizes suitable for applications such as commuter transports and helicopters. The study engine designs were derived from relevant engine development background including both prior and recent engine test results using direct injected unthrottled rotary engine technology. Aircraft studies, using these resultant growth engines, define anticipated system effects of the performance and power density improvements for both single engine and twin engine airplanes. The calculated results indicate superior system performance and 27 to 33 percent fuel economy improvement for the rotary engine airplanes as compared to equivalent airframe concept designs with current baseline engines. The research and technology activities required to attain the projected engine performance levels are also discussed.

  15. Study of advanced fuel system concepts for commercial aircraft and engines

    NASA Technical Reports Server (NTRS)

    Versaw, E. F.; Brewer, G. D.; Byers, W. D.; Fogg, H. W.; Hanks, D. E.; Chirivella, J.

    1983-01-01

    The impact on a commercial transport aircraft of using fuels which have relaxed property limits relative to current commercial jet fuel was assessed. The methodology of the study is outlined, fuel properties are discussed, and the effect of the relaxation of fuel properties analyzed. Advanced fuel system component designs that permit the satisfactory use of fuel with the candidate relaxed properties in the subject aircraft are described. The two fuel properties considered in detail are freezing point and thermal stability. Three candidate fuel system concepts were selected and evaluated in terms of performance, cost, weight, safety, and maintainability. A fuel system that incorporates insulation and electrical heating elements on fuel tank lower surfaces was found to be most cost effective for the long term.

  16. Experimental evaluation of combustor concepts for burning broad property fuels

    NASA Technical Reports Server (NTRS)

    Kasper, J. M.; Ekstedt, E. E.; Dodds, W. J.; Shayeson, M. W.

    1980-01-01

    A baseline CF6-50 combustor and three advanced combustor designs were evaluated to determine the effects of combustor design on operational characteristics using broad property fuels. Three fuels were used in each test: Jet A, a broad property 13% hydrogen fuel, and a 12% hydrogen fuel blend. Testing was performed in a sector rig at true cruise and simulated takeoff conditions for the CF6-50 engine cycle. The advanced combustors (all double annular, lean dome designs) generally exhibited lower metal temperatures, exhaust emissions, and carbon buildup than the baseline CF6-50 combustor. The sensitivities of emissions and metal temperatures to fuel hydrogen content were also generally lower for the advanced designs. The most promising advanced design used premixing tubes in the main stage. This design was chosen for additional testing in which fuel/air ratio, reference velocity, and fuel flow split were varied.

  17. Determination of nuclear fuel burn-up axial profile by neutron emission measurement

    NASA Astrophysics Data System (ADS)

    Prokopowicz, Rafal; Pytel, Krzysztof

    2016-12-01

    Burning-up of nuclear fuel is usually not a space-isotropic phenomenon. It depends on both the neutron flux density and energy spectrum distribution during fuel operation in a nuclear reactor. This paper presents the method of measurement of burn-up spatial distribution of spent nuclear fuel element. The method is based on recording of the neutron emission from investigated fuel element. Based on performed analyses and calculations, a suitable measuring setup has been designed and constructed. The subjects of investigation were fuel elements used in the MARIA research reactor, operated by National Centre for Nuclear Research in Świerk, Poland. The results of measurements made over a period of several years by means of the described method are presented in the paper.

  18. Fuel-rich, catalytic reaction experimental results. [fuel development for high-speed civil transport aircraft

    NASA Technical Reports Server (NTRS)

    Rollbuhler, Jim

    1991-01-01

    Future aeropropulsion gas turbine combustion requirements call for operating at very high inlet temperatures, pressures, and large temperature rises. At the same time, the combustion process is to have minimum pollution effects on the environment. Aircraft gas turbine engines utilize liquid hydrocarbon fuels which are difficult to uniformly atomize and mix with combustion air. An approach for minimizing fuel related problems is to transform the liquid fuel into gaseous form prior to the completion of the combustion process. Experimentally obtained results are presented for vaporizing and partially oxidizing a liquid hydrocarbon fuel into burnable gaseous components. The presented experimental data show that 1200 to 1300 K reaction product gas, rich in hydrogen, carbon monoxide, and light-end hydrocarbons, is formed when flowing 0.3 to 0.6 fuel to air mixes through a catalyst reactor. The reaction temperatures are kept low enough that nitrogen oxides and carbon particles (soot) do not form. Results are reported for tests using different catalyst types and configurations, mass flowrates, input temperatures, and fuel to air ratios.

  19. Simulation of differential die-away instrument’s response to asymmetrically burned spent nuclear fuel

    SciTech Connect

    Martinik, Tomas; Henzl, Vladimir; Grape, Sophie; Svard, Staffan Jacobsson; Jansson, Peter; Swinhoe, Martyn T.; Tobin, Stephen J.

    2015-03-04

    Here, previous simulation studies of Differential Die–Away (DDA) instrument’s response to active interrogation of spent nuclear fuel from a pressurized water reactor (PWR) yielded promising results in terms of its capability to accurately measure or estimate basic spent fuel assembly (SFA) characteristics, such as multiplication, initial enrichment (IE) and burn-up (BU) as well as the total plutonium content. These studies were however performed only for a subset of idealized SFAs with a symmetric BU with respect to its longitudinal axis. Therefore, to complement the previous results, additional simulations have been performed of the DDA instrument’s response to interrogation of asymmetrically burned spent nuclear fuel in order to determine whether detailed assay of SFAs from all 4 sides will be necessary in real life applications or whether a cost and time saving single sided assay could be used to achieve results of similar quality as previously reported in case of symmetrically burned SFAs.

  20. Effects of Burning Alternative Fuel in a 5-Cup Combustor Sector

    NASA Technical Reports Server (NTRS)

    Tacina, K. M.; Chang, C. T.; Lee, C.-M.; He, Z.; Herbon, J.

    2015-01-01

    A goal of NASA's Environmentally Responsible Aviation (ERA) program is to develop a combustor that will reduce the NOx emissions and that can burn both standard and alternative fuels. To meet this goal, NASA partnered with General Electric Aviation to develop a 5-cup combustor sector; this sector was tested in NASA Glenn's Advanced Subsonic Combustion Rig (ASCR). To verify that the combustor sector was fuel-flexible, it was tested with a 50-50 blend of JP-8 and a biofuel made from the camelina sativa plant. Results from this test were compared to results from tests where the fuel was neat JP-8. Testing was done at three combustor inlet conditions: cruise, 30% power, and 7% power. When compared to burning JP-8, burning the 50-50 blend did not significantly affect emissions of NOx, CO, or total hydrocarbons. Furthermore, it did not significantly affect the magnitude and frequency of the dynamic pressure fluctuations.

  1. Understanding electrostatic charge behaviour in aircraft fuel systems

    NASA Astrophysics Data System (ADS)

    Ogilvy, Jill A.; Hooker, Phil; Bennett, Darrell

    2015-10-01

    This paper presents work on the simulation of electrostatic charge build-up and decay in aircraft fuel systems. A model (EC-Flow) has been developed by BAE Systems under contract to Airbus, to allow the user to assess the effects of changes in design or in refuel conditions. Some of the principles behind the model are outlined. The model allows for a range of system components, including metallic and non-metallic pipes, valves, filters, junctions, bends and orifices. A purpose-built experimental rig was built at the Health and Safety Laboratory in Buxton, UK, to provide comparison data. The rig comprises a fuel delivery system, a test section where different components may be introduced into the system, and a Faraday Pail for measuring generated charge. Diagnostics include wall currents, charge densities and pressure losses. This paper shows sample results from the fitting of model predictions to measurement data and shows how analysis may be used to explain some of the observed trends.

  2. A study of subsonic transport aircraft configurations using hydrogen (H2) and methane (CH4) as fuel

    NASA Technical Reports Server (NTRS)

    Snow, D. B.; Avery, B. D.; Bodin, L. A.; Baldasare, P.; Washburn, G. F.

    1974-01-01

    The acceptability of alternate fuels for future commercial transport aircraft are discussed. Using both liquid hydrogen and methane, several aircraft configurations are developed and energy consumption, aircraft weights, range and payload are determined and compared to a conventional Boeing 747-100 aircraft. The results show that liquid hydrogen can be used to reduce aircraft energy consumption and that methane offers no advantage over JP or hydrogen fuel.

  3. Influence of Jet Fuel Composition on Aircraft Engine Emissions: A Synthesis of Aerosol Emissions Data from the NASA APEX, AAFEX, and ACCESS Missions

    NASA Astrophysics Data System (ADS)

    Moore, R.; Shook, M.; Beyersdorf, A. J.; Corr, C.; Herndon, S. C.; Knighton, W. B.; Miake-Lye, R. C.; Thornhill, K. L., II; Winstead, E.; Yu, Z.; Ziemba, L. D.; Anderson, B. E.

    2015-12-01

    We statistically analyze the impact of jet fuel properties on aerosols emitted by the NASA McDonnell Douglas DC-8 CFM56-2-C1 engines burning fifteen different aviation fuels. Data were collected for this single engine type during four different, comprehensive ground tests conducted over the past decade, which allow us to clearly link changes in aerosol emissions to fuel compositional changes. It is found that the volatile aerosol fraction dominates the number and volume emissions indices (EIs) over all engine powers, which are driven by changes in fuel aromatic and sulfur content. Meanwhile, the naphthalenic content of the fuel determines the magnitude of the non-volatile number and volume EI as well as the black carbon mass EI. Linear regression coefficients are reported for each aerosol EI in terms of these properties, engine fuel flow rate, and ambient temperature, and show that reducing both fuel sulfur content and napththalenes to near-zero levels would result in roughly a ten-fold decrease in aerosol number emitted per kg of fuel burn. This work informs future efforts to model aircraft emissions changes as the aviation fleet gradually begins to transition toward low-aromatic, low-sulfur alternative jet fuels from bio-based or Fischer-Tropsch production pathways.

  4. EVALUATION OF CARBON BLACK SLURRIES AS CLEAN BURNING FUELS

    EPA Science Inventory

    Experiments were performed to examine the pumpability, atomization and combustion characteristics of slurries made of mixtures of carbon black with No. 2 fuel oil and methanol. Carbon black-No. 2 fuel oil and carbon black-methanol slurries, with carbon black contents of up to 50 ...

  5. Methods and apparatus for burning fuel with low NO[sub x] formation

    SciTech Connect

    Schwartz, R.E.; Waibel, R.T.; Rodden, P.M.; Napier, S.O.

    1992-10-13

    This patent describes an improved burner aparatus for discharging a mixture of fuel and air into a furnace space wherein the mixture is burned and flue gases having low NO[sub x] content are formed therefrom. It comprises: A housing; primary mixer-nozzle means; flue gases passageway means; at least one secondary fuel nozzel means. This patent also describes a method of discharging an at least substanitally stoichiometric mixture of fuel and air into a furnace wherein the mixture is burned and flue gases having low NO[sub x] content are formed therefrom. It comprises: discharging air into the furnace; discharging the remaining portion of the fuel into a secondary zone.

  6. Mathematical simulation of hydrocarbon fuel conversion in heat-protection elements of hypersonic aircrafts

    NASA Astrophysics Data System (ADS)

    Kuranov, A. L.; Korabel'nikov, A. V.; Mikhailov, A. M.

    2017-01-01

    We consider a mathematical model of hydrocarbon fuel conversion in a thermochemical reactor as an element of heat protection of a hypersonic aircraft. The application of this model has made it possible to enrich information obtained in experimental studies.

  7. The knocking characteristics of fuels in relation to maximum permissible performance of aircraft engines

    NASA Technical Reports Server (NTRS)

    Rothrock, A M; Biermann, Arnold E

    1939-01-01

    An analysis is presented of the relationship of various engine factors to knock in preignition in an aircraft engine. From this analysis and from the available experimental data, a method of evaluating the knocking characteristics of the fuel in an aircraft-engine cylinder is suggested.

  8. Simplified jet fuel reaction mechanism for lean burn combustion application

    NASA Technical Reports Server (NTRS)

    Lee, Chi-Ming; Kundu, Krishna; Ghorashi, Bahman

    1993-01-01

    Successful modeling of combustion and emissions in gas turbine engine combustors requires an adequate description of the reaction mechanism. Detailed mechanisms contain a large number of chemical species participating simultaneously in many elementary kinetic steps. Current computational fluid dynamic models must include fuel vaporization, fuel-air mixing, chemical reactions, and complicated boundary geometries. A five-step Jet-A fuel mechanism which involves pyrolysis and subsequent oxidation of paraffin and aromatic compounds is presented. This mechanism is verified by comparing with Jet-A fuel ignition delay time experimental data, and species concentrations obtained from flametube experiments. This five-step mechanism appears to be better than the current one- and two-step mechanisms.

  9. A study of external fuel vaporization. [for aircraft gas turbine engines

    NASA Technical Reports Server (NTRS)

    Szetela, E. J.; Chiappetta, L.; Baker, C. E.

    1981-01-01

    Candidate external vaporizer designs for an aircraft gas turbine engine are evaluated with respect to fuel thermal stability, integration of the vaporizer system into the aircraft engine, engine and vaporizer dynamic response, startup and altitude restart, engine performance, control requirements, safety, and maintenance. The selected concept is shown to offer potential gains in engine performance in terms of reduced specific fuel consumption and improved engine thrust/weight ratio. The thrust/weight improvement can be traded against vaporization system weight.

  10. Particulate Matter Stack Emission Compliance Test Procedure for Fuel Burning Units.

    ERIC Educational Resources Information Center

    West Virginia Air Pollution Control Commission, Charleston.

    This publication details the particulate matter emissions test procedure that is applicable for conducting compliance tests for fuel burning units required to be tested under Sub-section 7 of Regulation II (1972) as established by the state of West Virginia Air Pollution Control Commission. The testing procedure is divided into five parts:…

  11. Here's a way to burn low-quality fuels in suspension

    SciTech Connect

    Schwieger, B.

    1980-02-01

    Three systems of fluidized-bed combustion for steam production in the U.S. are described. It is stated that one of the benefits of fluidized beds is their ability to combust with relative ease, problem fuels - such as high-ash woodwaste and slow-burning char. The systems described use log-yard waste, hogged woodwaste, sawdust and wood pellets.

  12. A fuselage/tank structure study for actively cooled hypersonic cruise vehicles, summary. [aircraft design of aircraft fuel systems

    NASA Technical Reports Server (NTRS)

    Pirrello, C. J.; Baker, A. H.; Stone, J. E.

    1976-01-01

    A detailed analytical study was made to investigate the effects of fuselage cross section (circular and elliptical) and the structural arrangement (integral and nonintegral tanks) on aircraft performance. The vehicle was a 200 passenger, liquid hydrogen fueled Mach 6 transport designed to meet a range goal of 9.26 Mn (5000 NM). A variety of trade studies were conducted in the area of configuration arrangement, structural design, and active cooling design in order to maximize the performance of each of three point design aircraft: (1) circular wing-body with nonintegral tanks, (2) circular wing-body with integral tanks and (3) elliptical blended wing-body with integral tanks. Aircraft range and weight were used as the basis for comparison. The resulting design and performance characteristics show that the blended body integral tank aircraft weights the least and has the greatest range capability, however, producibility and maintainability factors favor nonintegral tank concepts.

  13. Aircraft-measured indirect cloud effects from biomass burning smoke in the Arctic and subarctic

    DOE PAGES

    Zamora, Lauren M.; Kahn, R. A.; Cubison, M. J.; ...

    2016-01-21

    The incidence of wildfires in the Arctic and subarctic is increasing; in boreal North America, for example, the burned area is expected to increase by 200–300% over the next 50–100 years, which previous studies suggest could have a large effect on cloud microphysics, lifetime, albedo, and precipitation. However, the interactions between smoke particles and clouds remain poorly quantified due to confounding meteorological influences and remote sensing limitations. Here, we use data from several aircraft campaigns in the Arctic and subarctic to explore cloud microphysics in liquid-phase clouds influenced by biomass burning. Median cloud droplet radii in smoky clouds were ~40–60% smallermore » than in background clouds. Based on the relationship between cloud droplet number (Nliq) and various biomass burning tracers (BBt) across the multi-campaign data set, we calculated the magnitude of subarctic and Arctic smoke aerosol–cloud interactions (ACIs, where ACI = (1/3) × dln(Nliq)/dln(BBt)) to be ~0.16 out of a maximum possible value of 0.33 that would be obtained if all aerosols were to nucleate cloud droplets. Interestingly, in a separate subarctic case study with low liquid water content (~0.02gm–3) and very high aerosol concentrations (2000–3000 cm–3) in the most polluted clouds, the estimated ACI value was only 0.05. In this case, competition for water vapor by the high concentration of cloud condensation nuclei (CCN) strongly limited the formation of droplets and reduced the cloud albedo effect, which highlights the importance of cloud feedbacks across scales. Using our calculated ACI values, we estimate that the smoke-driven cloud albedo effect may decrease local summertime short-wave radiative flux by between 2 and 4 Wm–2 or more under some low and homogeneous cloud cover conditions in the subarctic, although the changes should be smaller in high surface albedo regions of the Arctic. Furthermore, we lastly explore evidence suggesting that

  14. Aircraft-Measured Indirect Cloud Effects from Biomass Burning Smoke in the Arctic and Subarctic

    NASA Technical Reports Server (NTRS)

    Zamora, L. M.; Kahn, R. A.; Cubison, M. J.; Diskin, G. S.; Jimenez, J. L.; Kondo, Y.; McFarquhar, G. M.; Nenes, A.; Thornhill, K. L.; Wisthaler, A.; Zelenyuk, A.; Ziemba, L. D.

    2016-01-01

    The incidence of wildfires in the Arctic and subarctic is increasing; in boreal North America, for example, the burned area is expected to increase by 200-300% over the next 50-100 years, which previous studies suggest could have a large effect on cloud microphysics, lifetime, albedo, and precipitation. However, the interactions between smoke particles and clouds remain poorly quantified due to confounding meteorological influences and remote sensing limitations. Here, we use data from several aircraft campaigns in the Arctic and subarctic to explore cloud microphysics in liquid-phase clouds influenced by biomass burning. Median cloud droplet radii in smoky clouds were approx. 40- 60% smaller than in background clouds. Based on the relationship between cloud droplet number (N(liq)/ and various biomass burning tracers (BBt/ across the multi-campaign data set, we calculated the magnitude of subarctic and Arctic smoke aerosol-cloud interactions (ACIs, where ACI = (1/3) x dln(N(liq))/dln(BBt)) to be approx. 0.16 out of a maximum possible value of 0.33 that would be obtained if all aerosols were to nucleate cloud droplets. Interestingly, in a separate subarctic case study with low liquid water content (0.02 gm/cu m and very high aerosol concentrations (2000- 3000/ cu cm in the most polluted clouds, the estimated ACI value was only 0.05. In this case, competition for water vapor by the high concentration of cloud condensation nuclei (CCN) strongly limited the formation of droplets and reduced the cloud albedo effect, which highlights the importance of cloud feedbacks across scales. Using our calculated ACI values, we estimate that the smoke-driven cloud albedo effect may decrease local summertime short-wave radiative flux by between 2 and 4 W/sq m or more under some low and homogeneous cloud cover conditions in the subarctic, although the changes should be smaller in high surface albedo regions of the Arctic.We lastly explore evidence suggesting that numerous northern

  15. Aircraft-measured indirect cloud effects from biomass burning smoke in the Arctic and subarctic

    SciTech Connect

    Zamora, Lauren M.; Kahn, R. A.; Cubison, M. J.; Diskin, G. S.; Jimenez, J. L.; Kondo, Y.; McFarquhar, G. M.; Nenes, A.; Thornhill, K. L.; Wisthaler, A.; Zelenyuk, A.; Ziemba, L. D.

    2016-01-21

    The incidence of wildfires in the Arctic and subarctic is increasing; in boreal North America, for example, the burned area is expected to increase by 200–300% over the next 50–100 years, which previous studies suggest could have a large effect on cloud microphysics, lifetime, albedo, and precipitation. However, the interactions between smoke particles and clouds remain poorly quantified due to confounding meteorological influences and remote sensing limitations. Here, we use data from several aircraft campaigns in the Arctic and subarctic to explore cloud microphysics in liquid-phase clouds influenced by biomass burning. Median cloud droplet radii in smoky clouds were ~40–60% smaller than in background clouds. Based on the relationship between cloud droplet number (Nliq) and various biomass burning tracers (BBt) across the multi-campaign data set, we calculated the magnitude of subarctic and Arctic smoke aerosol–cloud interactions (ACIs, where ACI = (1/3) × dln(Nliq)/dln(BBt)) to be ~0.16 out of a maximum possible value of 0.33 that would be obtained if all aerosols were to nucleate cloud droplets. Interestingly, in a separate subarctic case study with low liquid water content (~0.02gm–3) and very high aerosol concentrations (2000–3000 cm–3) in the most polluted clouds, the estimated ACI value was only 0.05. In this case, competition for water vapor by the high concentration of cloud condensation nuclei (CCN) strongly limited the formation of droplets and reduced the cloud albedo effect, which highlights the importance of cloud feedbacks across scales. Using our calculated ACI values, we estimate that the smoke-driven cloud albedo effect may decrease local summertime short-wave radiative flux by between 2 and 4 Wm–2 or more under some low and homogeneous cloud cover conditions in the subarctic, although the changes should be smaller in high

  16. Aircraft-Measured Indirect Cloud Effects from Biomass Burning Smoke in the Arctic and Subarctic

    NASA Technical Reports Server (NTRS)

    Zamora, Lauren; Kahn, R. A.; Cubison, M. C.; Diskin, G. S.; Jimenez, J. L.; Kondo, Y.; McFarquhar, G. M.; Nenes, A.; Wisthaler, A.; Zelenyuk, A.; Ziemba, L.

    2016-01-01

    The incidence of wildfires in the Arctic and subarctic is increasing; in boreal North America, for example, the burned area is expected to increase by 200-300 over the next 50-100 years, which previous studies suggest could have a large effect on cloud microphysics, lifetime, albedo, and precipitation. However, the interactions between smoke particles and clouds remain poorly quantified due to confounding meteorological influences and remote sensing limitations. Here, we use data from several aircraft campaigns in the Arctic and subarctic to explore cloud microphysics in liquid-phase clouds influenced by biomass burning. Median cloud droplet radii in smoky clouds were 50 smaller than in background clouds. Based on the relationship between cloud droplet number (N(liq))/ and various biomass burning tracers (BBt/ across the multi-campaign dataset, we calculated the magnitude of subarctic and Arctic smoke aerosol-cloud interactions (ACI, where ACI = (1/3) x dln(N(liq))/dln(BBt)) to be 0.12 out of a maximum possible value of 0.33 that would be obtained if all aerosols were to nucleate cloud droplets. Interestingly, in a separate subarctic case study with low liquid water content (0.02 gm/ cu m) and very high aerosol concentrations (2000-3000 cu m) in the most polluted clouds, the estimated ACI value was only 0.06. In this case, competition for water vapor by the high concentration of CCN strongly limited the formation of droplets and reduced the cloud albedo effect, which highlights the importance of cloud feedbacks across scales. Using our calculated ACI values, we estimate that the smoke-driven cloud albedo effect may decrease shortwave radiative flux by 2 and 4 W/sq or more under some low and homogeneous cloud cover conditions in the subarctic, although the changes should be smaller in high surface albedo regions of the Arctic. We lastly show evidence to suggest that numerous northern latitude background Aitken particles can interact with combustion particles

  17. Aircraft-measured indirect cloud effects from biomass burning smoke in the Arctic and subarctic

    NASA Astrophysics Data System (ADS)

    Zamora, L. M.; Kahn, R. A.; Cubison, M. J.; Diskin, G. S.; Jimenez, J. L.; Kondo, Y.; McFarquhar, G. M.; Nenes, A.; Thornhill, K. L.; Wisthaler, A.; Zelenyuk, A.; Ziemba, L. D.

    2016-01-01

    The incidence of wildfires in the Arctic and subarctic is increasing; in boreal North America, for example, the burned area is expected to increase by 200-300 % over the next 50-100 years, which previous studies suggest could have a large effect on cloud microphysics, lifetime, albedo, and precipitation. However, the interactions between smoke particles and clouds remain poorly quantified due to confounding meteorological influences and remote sensing limitations. Here, we use data from several aircraft campaigns in the Arctic and subarctic to explore cloud microphysics in liquid-phase clouds influenced by biomass burning. Median cloud droplet radii in smoky clouds were ˜ 40-60 % smaller than in background clouds. Based on the relationship between cloud droplet number (Nliq) and various biomass burning tracers (BBt) across the multi-campaign data set, we calculated the magnitude of subarctic and Arctic smoke aerosol-cloud interactions (ACIs, where ACI = (1/3) × dln(Nliq)/dln(BBt)) to be ˜ 0.16 out of a maximum possible value of 0.33 that would be obtained if all aerosols were to nucleate cloud droplets. Interestingly, in a separate subarctic case study with low liquid water content ( ˜ 0.02 g m-3) and very high aerosol concentrations (2000-3000 cm-3) in the most polluted clouds, the estimated ACI value was only 0.05. In this case, competition for water vapor by the high concentration of cloud condensation nuclei (CCN) strongly limited the formation of droplets and reduced the cloud albedo effect, which highlights the importance of cloud feedbacks across scales. Using our calculated ACI values, we estimate that the smoke-driven cloud albedo effect may decrease local summertime short-wave radiative flux by between 2 and 4 W m-2 or more under some low and homogeneous cloud cover conditions in the subarctic, although the changes should be smaller in high surface albedo regions of the Arctic. We lastly explore evidence suggesting that numerous northern

  18. Aircraft-measured indirect cloud effects from biomass burning smoke in the Arctic and subarctic

    NASA Astrophysics Data System (ADS)

    Zamora, L. M.; Kahn, R. A.; Cubison, M. J.; Diskin, G. S.; Jimenez, J. L.; Kondo, Y.; McFarquhar, G. M.; Nenes, A.; Thornhill, K. L.; Wisthaler, A.; Zelenyuk, A.; Ziemba, L. D.

    2015-08-01

    The incidence of wildfires in the Arctic and subarctic is increasing; in boreal North America, for example, the burned area is expected to increase by 200-300 % over the next 50-100 years, which previous studies suggest could have a large effect on cloud microphysics, lifetime, albedo, and precipitation. However, the interactions between smoke particles and clouds remain poorly quantified due to confounding meteorological influences and remote sensing limitations. Here, we use data from several aircraft campaigns in the Arctic and subarctic to explore cloud microphysics in liquid-phase clouds influenced by biomass burning. Median cloud droplet radii in smoky clouds were ~ 50 % smaller than in background clouds. Based on the relationship between cloud droplet number (Nliq) and various biomass burning tracers (BBt) across the multi-campaign dataset, we calculated the magnitude of subarctic and Arctic smoke aerosol-cloud interactions (ACI, where ACI = (1/3) × d ln (Nliq) / d ln (BBt)) to be ~ 0.12 out of a maximum possible value of 0.33 that would be obtained if all aerosols were to nucleate cloud droplets. Interestingly, in a separate subarctic case study with low liquid water content (~ 0.02 g m-3) and very high aerosol concentrations (2000-3000 cm-3) in the most polluted clouds, the estimated ACI value was only 0.06. In this case, competition for water vapor by the high concentration of CCN strongly limited the formation of droplets and reduced the cloud albedo effect, which highlights the importance of cloud feedbacks across scales. Using our calculated ACI values, we estimate that the smoke-driven cloud albedo effect may decrease shortwave radiative flux by 2-4 W m-2 or more under some low and homogeneous cloud cover conditions in the subarctic, although the changes should be smaller in high surface albedo regions of the Arctic. We lastly show evidence to suggest that numerous northern latitude background Aitken particles can interact with combustion particles

  19. Comparison of carbonaceous particulate matter emission factors among different solid fuels burned in residential stoves

    NASA Astrophysics Data System (ADS)

    Shen, Guofeng; Xue, Miao; Chen, Yuanchen; Yang, Chunli; Li, Wei; Shen, Huizhong; Huang, Ye; Zhang, Yanyan; Chen, Han; Zhu, Ying; Wu, Haisuo; Ding, Aijun; Tao, Shu

    2014-06-01

    Uncertainty in the emission factor (EF) usually contributes largely to the overall uncertainty in the emission inventory. In the present study, the locally measured EFs of particulate matter (PM), organic carbon (OC), and elemental carbon (EC) for solid fuels burned in the residential sector are compiled and compared. These fuels are classified into seven sub-groups of anthracite briquette, anthracite chunk, bituminous briquette, bituminous chunk, crop residue, fuel wood log, and brushwood/branches. The EFs of carbonaceous particles for these fuels vary significantly, generally in the order of anthracite (briquette and chunk) < wood log < brushwood/branches < crop residue < bituminous (briquette and chunk), with an exception that the brushwood/branches have a relatively high EF of EC. The ratio of EC/OC varies significantly among different fuels, and is generally higher for biomass fuel than that for coal because of the intense flaming conditions formed during the biomass burning process in improved stoves. Distinct ratios calls for a future study on the potential health and climate impacts of carbonaceous PM from the residential combustions of different fuels. A narrow classification of these fuels significantly reduces the variations in the EFs of PM, OC, and EC, and the temporal and geographical distributions of the emissions could be better characterized.

  20. Widespread Burning of Alaskan Boreal Forests Overcomes Fuel Limitation in the 21st Century

    NASA Astrophysics Data System (ADS)

    Kelly, R.; Hu, F.

    2015-12-01

    Fire is a key determinant of the structure and function of boreal forest ecosystems. Boreal fire regimes have been climate-limited in recent decades, and future climate warming is predicted to drive a pronounced increase in fire activity, likely resulting in carbon release from the boreal biome and positive feedback to climate change. Fuel limitation could slow fire regime change by reducing the abundance of mature vegetation on the landscape, but this mechanism remains poorly quantified and is thus excluded from forecasts of future boreal burning. We developed a novel statistical model that links regional area burned to mean landscape age, a proxy for fuel limitation due to cumulative past burning. Fit to historical fire observations from interior Alaska, the model detects significant evidence of fire-vegetation feedback and provides the first quantitative estimate of its effects on regional fire regimes. These effects were subtle during the past 60 yr, but they will become increasingly influential as climate warming promotes higher fire activity. By the end of the 21st century, fuel limitation reduces predicted area burned by 40-50% relative to predictions based on climate alone, and diminishes the difference between fire regimes expected under alternate future climate scenarios. Nevertheless, annual area burned will approximately double during the coming century as fire becomes more widespread in spite of regional fuel limitation. Furthermore, changes to the fire regime and mean landscape age by the end of the century could represent a fundamental shift in the Alaskan boreal ecosystem. Our model structure facilitates linking fire regime predictions to ecosystem and Earth system models and could help reduce uncertainty in these models due to poorly constrained initial conditions. We demonstrate this approach using the Terrestrial Ecosystem Model, which has been calibrated extensively for applications in simulating boreal carbon dynamics. Results suggest that

  1. Study of the application of hydrogen fuel to long-range subsonic transport aircraft. Volume 1: Summary

    NASA Technical Reports Server (NTRS)

    Brewer, G. D.; Morris, R. E.; Lange, R. H.; Moore, J. W.

    1975-01-01

    The feasibility of using liquid hydrogen as fuel in advanced designs of long range, subsonic transport aircraft is assessed. Both passenger and cargo type aircraft are investigated. Comparisons of physical, performance, and economic parameters of the LH2 fueled designs with conventionally fueled aircraft are presented. Design studies are conducted to determine appropriate characteristics for the hydrogen related systems required on board the aircraft. These studies included consideration of material, structural, and thermodynamic requirements of the cryogenic fuel tanks and fuel systems with the structural support and thermal protection systems.

  2. The influence of weather and fuel type on the fuel composition of the area burned by forest fires in Ontario, 1996-2006.

    PubMed

    Podur, Justin J; Martell, David L

    2009-07-01

    Forest fires are influenced by weather, fuels, and topography, but the relative influence of these factors may vary in different forest types. Compositional analysis can be used to assess the relative importance of fuels and weather in the boreal forest. Do forest or wild land fires burn more flammable fuels preferentially or, because most large fires burn in extreme weather conditions, do fires burn fuels in the proportions they are available despite differences in flammability? In the Canadian boreal forest, aspen (Populus tremuloides) has been found to burn in less than the proportion in which it is available. We used the province of Ontario's Provincial Fuels Database and fire records provided by the Ontario Ministry of Natural Resources to compare the fuel composition of area burned by 594 large (>40 ha) fires that occurred in Ontario's boreal forest region, a study area some 430,000 km2 in size, between 1996 and 2006 with the fuel composition of the neighborhoods around the fires. We found that, over the range of fire weather conditions in which large fires burned and in a study area with 8% aspen, fires burn fuels in the proportions that they are available, results which are consistent with the dominance of weather in controlling large fires.

  3. Ignition, Burning, and Extinction of a Strained Fuel Strip

    NASA Technical Reports Server (NTRS)

    Selerland, T.; Karagozian, A. R.

    1996-01-01

    Flame structure and ignition and extinction processes associated with a strained fuel strip are explored numerically using detailed transport and complex kinetics for a propane-air reaction. Ignition modes are identified that are similar to those predicted by one-step activation energy asymptotics, i.e., modes in which diffusion flames can ignite as independent or dependent interfaces, and modes in which single premixed or partially premixed flames ignite. These ignition modes are found to be dependent on critical combinations of strain rate, fuel strip thickness, and initial reactant temperatures. Extinction in this configuration is seen to occur due to fuel consumption by adjacent flames, although viscosity is seen to have the effect of delaying extinction by reducing the effective strain rate and velocity field experienced by the flames.

  4. Impacts of broadened-specification fuels on aircraft turbine engine combustors

    SciTech Connect

    Bahr, D.W.

    1982-11-01

    In the future, aircraft turbine engines may be required to accommodate fuels with lower hydrogen contents, fluidity/volatility characteristics, and thermal stability ratings than those of present-day jet fuels. The key results of several investigations conducted to quantify the impacts of such fuel property changes on the performance, pollutant emission, and durability characteristics of aircraft turbine engine combustors are reviewed. These results were obtained in both component and engine tests of the current production combustors used in the CF6-6, CF6-50, F101/CFM56, and J79/CJ805 engines. Based on these results, it is concluded that the most significant concerns associated with such fuel property changes are decreased combustor life, decreased ground starting/altitude relight capabilities, and increased fuel injector gumming/coking tendencies. The combustor design improvements that appear to be needed to permit the use of jet fuels of significantly lower quality than present day fuels are also reviewed.

  5. The impact of fuels on aircraft technology through the year 2000

    NASA Technical Reports Server (NTRS)

    Grobman, J.; Reck, G. M.

    1980-01-01

    The impact that the supply, quality, and processing costs of future fuels may have on aircraft technology is assessed. The potential range of properties for future jet fuels is discussed along with the establishment of a data base of fuel property effects on propulsion system components. Also, the evolution and evaluation of advanced component technology that would permit the use of broader property fuels and the identification of technical and economic trade-offs within the overall fuel production-air transportation system associated with variations in fuel properties are examined.

  6. Burns

    MedlinePlus

    ... cause swelling, blistering, scarring and, in serious cases, shock, and even death. They also can lead to infections because they damage your skin's protective barrier. Treatment for burns depends on the cause of the ...

  7. Stress Analysis of Coated Particle Fuel in the Deep-Burn Pebble Bed Reactor Design

    SciTech Connect

    B. Boer; A. M. Ougouag

    2010-05-01

    High fuel temperatures and resulting fuel particle coating stresses can be expected in a Pu and minor actinide fueled Pebble Bed Modular Reactor (400 MWth) design as compared to the ’standard’ UO2 fueled core. The high discharge burnup aimed for in this Deep-Burn design results in increased power and temperature peaking in the pebble bed near the inner and outer reflector. Furthermore, the pebble power in a multi-pass in-core pebble recycling scheme is relatively high for pebbles that make their first core pass. This might result in an increase of the mechanical failure of the coatings, which serve as the containment of radioactive fission products in the PBMR design. To investigate the integrity of the particle fuel coatings as a function of the irradiation time (i.e. burnup), core position and during a Loss Of Forced Cooling (LOFC) incident the PArticle STress Analysis code (PASTA) has been coupled to the PEBBED code for neutronics, thermal-hydraulics and depletion analysis of the core. Two deep burn fuel types (Pu with or without initial MA fuel content) have been investigated with the new code system for normal and transient conditions including the effect of the statistical variation of thickness of the coating layers.

  8. Irradiation performance of PFBR MOX fuel after 112 GWd/t burn-up

    NASA Astrophysics Data System (ADS)

    Venkiteswaran, C. N.; Jayaraj, V. V.; Ojha, B. K.; Anandaraj, V.; Padalakshmi, M.; Vinodkumar, S.; Karthik, V.; Vijaykumar, Ran; Vijayaraghavan, A.; Divakar, R.; Johny, T.; Joseph, Jojo; Thirunavakkarasu, S.; Saravanan, T.; Philip, John; Rao, B. P. C.; Kasiviswanathan, K. V.; Jayakumar, T.

    2014-06-01

    The 500 MWe Prototype Fast Breeder Reactor (PFBR) which is in advanced stage of construction at Kalpakkam, India, will use mixed oxide (MOX) fuel with a target burnup of 100 GWd/t. The fuel pellet is of annular design to enable operation at a peak linear power of 450 W/cm with the requirement of minimum duration of pre-conditioning. The performance of the MOX fuel and the D9 clad and wrapper material was assessed through Post Irradiation Examinations (PIE) after test irradiation of 37 fuel pin subassembly in Fast Breeder Test Reactor (FBTR) to a burn-up of 112 GWd/t. Fission product distribution, swelling and fuel-clad gap evolution, central hole diameter variation, restructuring, fission gas release and clad wastage due to fuel-clad chemical interaction were evaluated through non-destructive and destructive examinations. The examinations have indicated that the MOX fuel can safely attain the desired target burn-up in PFBR.

  9. Aircraft

    DTIC Science & Technology

    2002-01-01

    Company, Washington, DC Boeing Commercial Aircraft Division, Seattle, WA and Long Beach, CA Boeing Military Aircraft and Missile Division, St. Louis, MO and... aircraft ; military fixed-wing aircraft ; rotorcraft (helicopters and tiltrotor aircraft ); and aircraft jet engines. Two companies dominate the commercial... aircraft business, Boeing and Airbus. Four companies dominate the military fixed-wing market, Boeing, Lockheed Martin, BAE Systems, and European

  10. 49 CFR 173.172 - Aircraft hydraulic power unit fuel tank.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...-GENERAL REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS Non-bulk Packaging for Hazardous Materials Other Than... fuel tanks containing a mixture of anhydrous hydrazine and monomethyl hydrazine (M86 fuel) and designed for installation as complete units in aircraft are excepted from the specification...

  11. Simulation of differential die-away instrument's response to asymmetrically burned spent nuclear fuel

    NASA Astrophysics Data System (ADS)

    Martinik, Tomas; Henzl, Vladimir; Grape, Sophie; Svärd, Staffan Jacobsson; Jansson, Peter; Swinhoe, Martyn T.; Tobin, Stephen J.

    2015-07-01

    Previous simulation studies of Differential Die-Away (DDA) instrument's response to active interrogation of spent nuclear fuel from a pressurized water reactor (PWR) yielded promising results in terms of its capability to accurately measure or estimate basic spent fuel assembly (SFA) characteristics, such as multiplication, initial enrichment (IE) and burn-up (BU) as well as the total plutonium content. These studies were however performed only for a subset of idealized SFAs with a symmetric BU with respect to its longitudinal axis. Therefore, to complement the previous results, additional simulations have been performed of the DDA instrument's response to interrogation of asymmetrically burned spent nuclear fuel in order to determine whether detailed assay of SFAs from all 4 sides will be necessary in real life applications or whether a cost and time saving single sided assay could be used to achieve results of similar quality as previously reported in case of symmetrically burned SFAs. The results of this study suggest that DDA instrument response depends on the position of the individual neutron detectors and in fact can be split in two modes. The first mode, measured by the back detectors, is not significantly sensitive to the spatial distribution of fissile isotopes and neutron absorbers, but rather reflects the total amount of both contributors as in the cases of symmetrically burned SFAs. In contrary, the second mode, measured by the front detectors, yields certain sensitivity to the orientation of the asymmetrically burned SFA inside the assaying instrument. This study thus provides evidence that the DDA instrument can potentially be utilized as necessary in both ways, i.e. a quick determination of the average SFA characteristics in a single assay, as well as a more detailed characterization involving several DDA observables through assay of the SFA from all of its four sides that can possibly map the burn-up distribution and/or identify diversion or

  12. Estimated performance of an adaptive trailing-edge device aimed at reducing fuel consumption on a medium-size aircraft

    NASA Astrophysics Data System (ADS)

    Diodati, Gianluca; Concilio, Antonio; Ricci, Sergio; De Gaspari, Alessandro; Huvelin, Fabien; Dumont, Antoine; Godard, Jean-Luc

    2013-03-01

    This paper deals with the estimation of the performance of a medium-size aircraft (3-hour flight range) equipped with an adaptive trailing edge device (ATED) that runs span-wise from the wing root in the flap zone and extends chord-wise for a limited percentage of the MAC. Computations are calculated referring to the full wing and do not refer to the complete aircraft configuration. Aerodynamic computations, taking into account ideal shapes, have been performed by using both Euler and Navier- Stokes method in order to extract the wing polars for the reference and the optimal wing, implementing an ATED, deflected upwards and downwards. A comparison of the achieved results is discussed. Considering the shape domain, a suitable interpolation procedure has been set up to obtain the wing polar envelop of the adaptive wing, intended as the set of "best" values, picked by each different polar. At the end, the performances of the complete reference and adaptive wing are computed and compared for a symmetric, centered, leveled and steady cruise flight for a medium size aircraft. A significant fuel burn reduction estimate or, alternatively, an increased range capability is demonstrated, with margins of further improvements. The research leading to these results has gratefully received funding from the European Union Seventh Framework Programme (FP7/2007- 2013) under Grant Agreement n° 284562.

  13. Emission Reduction of Fuel-Staged Aircraft Engine Combustor Using an Additional Premixed Fuel Nozzle.

    PubMed

    Yamamoto, Takeshi; Shimodaira, Kazuo; Yoshida, Seiji; Kurosawa, Yoji

    2013-03-01

    The Japan Aerospace Exploration Agency (JAXA) is conducting research and development on aircraft engine technologies to reduce environmental impact for the Technology Development Project for Clean Engines (TechCLEAN). As a part of the project, combustion technologies have been developed with an aggressive target that is an 80% reduction over the NOx threshold of the International Civil Aviation Organization (ICAO) Committee on Aviation Environmental Protection (CAEP)/4 standard. A staged fuel nozzle with a pilot mixer and a main mixer was developed and tested using a single-sector combustor under the target engine's landing and takeoff (LTO) cycle conditions with a rated output of 40 kN and an overall pressure ratio of 25.8. The test results showed a 77% reduction over the CAEP/4 NOx standard. However, the reduction in smoke at thrust conditions higher than the 30% MTO condition and of CO emission at thrust conditions lower than the 85% MTO condition are necessary. In the present study, an additional fuel burner was designed and tested with the staged fuel nozzle in a single-sector combustor to control emissions. The test results show that the combustor enables an 82% reduction in NOx emissions relative to the ICAO CAEP/4 standard and a drastic reduction in smoke and CO emissions.

  14. Antimisting Fuel Research and Development for Commercial Aircraft

    DTIC Science & Technology

    1986-04-01

    aircraft boost pump with cold AMK. Later, the FAA added the following secondary objectives to the Boeing program: o Power requirements for degrading AMK...rWMRCIAL AIRCRAFT - FIIL SUMARY REPOIT ACT-320 6. Petforiirtg Organixat;o., Report No. 7. Au’torls) Michael Yaffee DOT/ FAA /CT-86/7 9. Parformina... FAA and England’s Royal Aircraft Establishment (RAE), which also had been conducting research in this area. The National Aeronautics and Space

  15. Evaluation of advanced lift concepts and fuel conservative short-haul aircraft, volume 1

    NASA Technical Reports Server (NTRS)

    Renshaw, J. H.; Bowden, M. K.; Narucki, C. W.; Bennett, J. A.; Smith, P. R.; Ferrill, R. S.; Randall, C. C.; Tibbetts, J. G.; Patterson, R. W.; Meyer, R. T.

    1974-01-01

    The performance and economics of a twin-engine augmentor wing airplane were evaluated in two phases. Design aspects of the over-the-wing/internally blown flap hybrid, augmentor wing, and mechanical flap aircraft were investigated for 910 m. field length with parametric extension to other field lengths. Fuel savings achievable by application of advanced lift concepts to short-haul aircraft were evaluated and the effect of different field lengths, cruise requirements, and noise levels on fuel consumption and airplane economics at higher fuel prices were determined. Conclusions and recommendations are presented.

  16. Effects of fuel properties on the burning characteristics of collision-merged alkane/water droplets

    SciTech Connect

    Wang, C.H.; Pan, K.L.; Huang, W.C.; Wen, H.C.; Yang, J.Y.; Law, C.K.

    2008-04-15

    The combustion characteristics of freely falling droplets, individually generated by the merging of colliding alkane and water droplets, were experimentally investigated. The outcome of the collision droplets was first studied and then the subsequent burning processes such as the flame appearance, ignition and burning behaviors were recorded, through either visual observation or microphotography with the aid of stroboscopic lighting. If the merged droplets were exhibited in an insertive manner, while the water droplet inserted into the alkane droplet, these yield the burning behaviors prior to the end of flame were very much similar to that of pure alkane. The burning was ended with droplet extinction for lower-C alkane, and with either droplet ''flash vaporization'' or extinction for hexadecane. And if the merged droplets were in adhesive manner, for hexadecane with large water content, they either could not be ignited for the large merged droplets, or be ignited with a much prolonged ignition delay, followed by a soot-reducing flame and an ending of droplet extinction for the small merged droplets. ''Homogeneous'' explosion was not observed in any of the tests, and ''heterogeneous'' explosion, induced by trapped air bubbles, occasionally occurred for merged droplets with C-atom in alkane is higher than dodecane. And the sudden disappearance of droplet definitely decreased the burning time and thus enhanced the burning intensity. Besides, the fuel mass consumption rates were increased, even in the cases that having droplet extinction, because of the enlargement of the surface area due to the stuffing of water droplet. (author)

  17. 40 CFR 63.1217 - What are the standards for liquid fuel boilers that burn hazardous waste?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... boilers that burn hazardous waste? 63.1217 Section 63.1217 Protection of Environment ENVIRONMENTAL... Waste Combustors Emissions Standards and Operating Limits for Solid Fuel Boilers, Liquid Fuel Boilers, and Hydrochloric Acid Production Furnaces § 63.1217 What are the standards for liquid fuel...

  18. 40 CFR 63.1217 - What are the standards for liquid fuel boilers that burn hazardous waste?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... boilers that burn hazardous waste? 63.1217 Section 63.1217 Protection of Environment ENVIRONMENTAL... Waste Combustors Emissions Standards and Operating Limits for Solid Fuel Boilers, Liquid Fuel Boilers, and Hydrochloric Acid Production Furnaces § 63.1217 What are the standards for liquid fuel...

  19. 40 CFR 63.1216 - What are the standards for solid fuel boilers that burn hazardous waste?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... boilers that burn hazardous waste? 63.1216 Section 63.1216 Protection of Environment ENVIRONMENTAL... Waste Combustors Emissions Standards and Operating Limits for Solid Fuel Boilers, Liquid Fuel Boilers, and Hydrochloric Acid Production Furnaces § 63.1216 What are the standards for solid fuel boilers...

  20. 40 CFR 63.1216 - What are the standards for solid fuel boilers that burn hazardous waste?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... boilers that burn hazardous waste? 63.1216 Section 63.1216 Protection of Environment ENVIRONMENTAL... Waste Combustors Emissions Standards and Operating Limits for Solid Fuel Boilers, Liquid Fuel Boilers, and Hydrochloric Acid Production Furnaces § 63.1216 What are the standards for solid fuel boilers...

  1. 40 CFR 63.1217 - What are the standards for liquid fuel boilers that burn hazardous waste?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... boilers that burn hazardous waste? 63.1217 Section 63.1217 Protection of Environment ENVIRONMENTAL... Waste Combustors Emissions Standards and Operating Limits for Solid Fuel Boilers, Liquid Fuel Boilers, and Hydrochloric Acid Production Furnaces § 63.1217 What are the standards for liquid fuel...

  2. Economic and environmental assessment of liquefied natural gas as a supplemental aircraft fuel

    NASA Astrophysics Data System (ADS)

    Withers, Mitch R.; Malina, Robert; Gilmore, Christopher K.; Gibbs, Jonathan M.; Trigg, Chris; Wolfe, Philip J.; Trivedi, Parthsarathi; Barrett, Steven R. H.

    2014-04-01

    In 2013, natural gas is 70-80% cheaper than jet fuel on an energy basis. As an alternative aviation fuel, natural gas may reduce operating costs. In this paper, we assess the use of liquefied natural gas (LNG) as a supplemental aircraft fuel in a military context, with detailed assessments of the Lockheed Martin C-130H and C-130J transport aircraft. We estimate the cost of retrofitting these aircraft to use LNG and the savings from reduced fuel expenses. We evaluate the societal impacts of LNG within a cost-benefit framework, taking into account resource consumption, human health impacts related to air quality, and climate damage. In order to compare alternative uses of natural gas in aviation, we include in our analysis Fischer-Tropsch (FT) jet fuel from natural gas as a drop-in alternative. Uncertainty analysis is performed with Monte Carlo simulations. We find that aircraft operators can save up to 14% on fuel expenses (retrofit costs included) by employing LNG retrofits, with a 95% confidence interval of 2-23%. Society can also benefit by 12% (3-20%) from LNG use as a result of improved surface air quality, lower resource consumption, and net climate neutrality. These results are highly dependent on fuel prices, the quantity and cost of the LNG retrofits, and the frequency and length of missions. FT jet fuel is not cost-competitive with conventional fuel and results in increased fuel expenses by 17%. FT fuel provides marginal societal benefits relative to jet fuel.

  3. Assessment of crash fire hazard of LH sub 2 fueled aircraft

    NASA Technical Reports Server (NTRS)

    Brewer, G. D.; Wittlin, G.; Versaw, E. F.; Parmley, R.; Cima, R.; Walther, E. G.

    1981-01-01

    The relative safety of passengers in LH2 - fueled aircraft, as well as the safety of people in areas surrounding a crash scene, has been evaluated in an analytical study. Four representative circumstances were postulated involving a transport aircraft in which varying degrees of severity of damage were sustained. Potential hazard to the passengers and to the surroundings posed by the spilled fuel was evaluated for each circumstance. Corresponding aircraft fueled with liquid methane, Jet A, and JP-4 were also studied in order to make comparisons of the relative safety. The four scenarios which were used to provide a basis for the evaluation included: (1) a small fuel leak internal to the aircraft, (2) a survivable crash in which a significant quantity of fuel is spilled in a radial pattern as a result of impact with a stationary object while taxiing at fairly low speed, (3) a survivable crash in which a significant quantity of fuel is spilled in an axial pattern as a result of impact during landing, and (4) a non-survivable crash in which a massive fuel spill occurs instantaneously.

  4. A compact breed and burn fast reactor using spent nuclear fuel blanket

    SciTech Connect

    Hartanto, D.; Kim, Y.

    2012-07-01

    A long-life breed-and-burn (B and B) type fast reactor has been investigated from the neutronics points of view. The B and B reactor has the capability to breed the fissile fuels and use the bred fuel in situ in the same reactor. In this work, feasibility of a compact sodium-cooled B and B fast reactor using spent nuclear fuel as blanket material has been studied. In order to derive a compact B and B fast reactor, a tight fuel lattice and relatively large fuel pin are used to achieve high fuel volume fraction. The core is initially loaded with an LEU (Low Enriched Uranium) fuel and a metallic fuel is used in the core. The Monte Carlo depletion has been performed for the core to see the long-term behavior of the B and B reactor. Several important parameters such as reactivity coefficients, delayed neutron fraction, prompt neutron generation lifetime, fission power, and fast neutron fluence, are analyzed through Monte Carlo reactor analysis. Evolution of the core fuel composition is also analyzed as a function of burnup. Although the long-life small B and B fast reactor is found to be feasible from the neutronics point of view, it is characterized to have several challenging technical issues including a very high fast neutron fluence of the structural materials. (authors)

  5. Aircraft emissions of methane and nitrous oxide during the alternative aviation fuel experiment.

    PubMed

    Santoni, Gregory W; Lee, Ben H; Wood, Ezra C; Herndon, Scott C; Miake-Lye, Richard C; Wofsy, Steven C; McManus, J Barry; Nelson, David D; Zahniser, Mark S

    2011-08-15

    Given the predicted growth of aviation and the recent developments of alternative aviation fuels, quantifying methane (CH(4)) and nitrous oxide (N(2)O) emission ratios for various aircraft engines and fuels can help constrain projected impacts of aviation on the Earth's radiative balance. Fuel-based emission indices for CH(4) and N(2)O were quantified from CFM56-2C1 engines aboard the NASA DC-8 aircraft during the first Alternative Aviation Fuel Experiment (AAFEX-I) in 2009. The measurements of JP-8 fuel combustion products indicate that at low thrust engine states (idle and taxi, or 4% and 7% maximum rated thrusts, respectively) the engines emit both CH(4) and N(2)O at a mean ± 1σ rate of 170 ± 160 mg CH(4) (kg Fuel)(-1) and 110 ± 50 mg N(2)O (kg Fuel)(-1), respectively. At higher thrust levels corresponding to greater fuel flow and higher engine temperatures, CH(4) concentrations in engine exhaust were lower than ambient concentrations. Average emission indices for JP-8 fuel combusted at engine thrusts between 30% and 100% of maximum rating were -54 ± 33 mg CH(4) (kg Fuel)(-1) and 32 ± 18 mg N(2)O (kg Fuel)(-1), where the negative sign indicates consumption of atmospheric CH(4) in the engine. Emission factors for the synthetic Fischer-Tropsch fuels were statistically indistinguishable from those for JP-8.

  6. High Burn-Up Spent Nuclear Fuel Vibration Integrity Study

    SciTech Connect

    Wang, Jy-An John; Wang, Hong; Jiang, Hao; Bevard, Bruce Balkcom; Howard, Rob L; Scaglione, John M

    2015-01-01

    The Oak Ridge National Laboratory (ORNL) has developed the cyclic integrated reversible-bending fatigue tester (CIRFT) approach to successfully demonstrate the controllable fatigue fracture on high burnup (HBU) spent nuclear fuel (SNF) in a normal vibration mode. CIRFT enables examination of the underlying mechanisms of SNF system dynamic performance. Due to the inhomogeneous composite structure of the SNF system, the detailed mechanisms of the pellet-pellet and pellet-clad interactions and the stress concentration effects at the pellet-pellet interface cannot be readily obtained from a CIRFT system measurement. Therefore, finite element analyses (FEAs) are used to translate the global moment-curvature measurement into local stress-strain profiles for further investigation. The major findings of CIRFT on the HBU SNF are as follows: SNF system interface bonding plays an important role in SNF vibration performance. Fuel structure contributes to SNF system stiffness. There are significant variations in stress and curvature of SNF systems during vibration cycles resulting from segment pellets and clad interactions. SNF failure initiates at the pellet-pellet interface region and appears to be spontaneous.

  7. Fuel characteristics pertinent to the design of aircraft fuel systems, Supplement I : additional information on MIL-F-7914(AER) grade JP-5 fuel and several fuel oils

    NASA Technical Reports Server (NTRS)

    Barnett, Henry C; Hibbard, Robert R

    1953-01-01

    Since the release of the first NACA publication on fuel characteristics pertinent to the design of aircraft fuel systems (NACA-RM-E53A21), additional information has become available on MIL-F7914(AER) grade JP-5 fuel and several of the current grades of fuel oils. In order to make this information available to fuel-system designers as quickly as possible, the present report has been prepared as a supplement to NACA-RM-E53A21. Although JP-5 fuel is of greater interest in current fuel-system problems than the fuel oils, the available data are not as extensive. It is believed, however, that the limited data on JP-5 are sufficient to indicate the variations in stocks that the designer must consider under a given fuel specification. The methods used in the preparation and extrapolation of data presented in the tables and figures of this supplement are the same as those used in NACA-RM-E53A21.

  8. Influence of fuel sulfur on the composition of aircraft exhaust plumes: The experiments SULFUR 1-7

    NASA Astrophysics Data System (ADS)

    Schumann, U.; Arnold, F.; Busen, R.; Curtius, J.; Kärcher, B.; Kiendler, A.; Petzold, A.; Schlager, H.; Schröder, F.; Wohlfrom, K.-H.

    2002-08-01

    The series of SULFUR experiments was performed to determine the aerosol particle and contrail formation properties of aircraft exhaust plumes for different fuel sulfur contents (FSC, from 2 to 5500 μg/g), flight conditions, and aircraft (ATTAS, A310, A340, B707, B747, B737, DC8, DC10). This paper describes the experiments and summarizes the results obtained, including new results from SULFUR 7. The conversion fraction ɛ of fuel sulfur to sulfuric acid is measured in the range 0.34 to 4.5% for an older (Mk501) and 3.3 +/- 1.8% for a modern engine (CFM56-3B1). For low FSC, ɛ is considerably smaller than what is implied by the volume of volatile particles in the exhaust. For FSC >= 100 μg/g and ɛ as measured, sulfuric acid is the most important precursor of volatile aerosols formed in aircraft exhaust plumes of modern engines. The aerosol measured in the plumes of various aircraft and models suggests ɛ to vary between 0.5 and 10% depending on the engine and its state of operation. The number of particles emitted from various subsonic aircraft engines or formed in the exhaust plume per unit mass of burned fuel varies from 2 × 1014 to 3 × 1015 kg-1 for nonvolatile particles (mainly black carbon or soot) and is of order 2 × 1017 kg-1 for volatile particles >1.5 nm at plume ages of a few seconds. Chemiions (CIs) formed in kerosene combustion are found to be quite abundant and massive. CIs contain sulfur-bearing molecules and organic matter. The concentration of CIs at engine exit is nearly 109 cm-3. Positive and negative CIs are found with masses partially exceeding 8500 atomic mass units. The measured number of volatile particles cannot be explained with binary homogeneous nucleation theory but is strongly related to the number of CIs. The number of ice particles in young contrails is close to the number of soot particles at low FSC and increases with increasing FSC. Changes in soot particles and FSC have little impact on the threshold temperature for contrail

  9. Fire Emissions Estimates in Siberia: Evaluation of Uncertainties in Area Burned, Land Cover, and Fuel Consumption

    NASA Astrophysics Data System (ADS)

    Kukavskaya, E.; Soja, A. J.; Ivanova, G. A.; Petkov, A.; Ponomarev, E. I.; Conard, S. G.

    2012-12-01

    Wildfire is one of the main disturbance factors in the boreal zone of Russia. Fires in the Russian boreal forest range from low-severity surface fires to high-severity crown fires. Estimates of carbon emissions from fires in Russia vary substantially due to differences in ecosystem classification and mapping, burned area calculations, and estimates of fuel consumption. We examined uncertainties in different parameters used to estimate biomass burning emissions. Several fire datasets (Institute of Forest burned area product, MCD45, MCD64, MOD14/MYD14, official data) were compared to estimate uncertainties in area burned in Siberia. Area burned was found to differ significantly by data source, with satellite data being by an order of magnitude greater than ground-based data. Differences between mapped ecosystems were also compared and contrasted on the basis of five land cover maps (GLC-2000, Globcover-2009, MODIS Collection 4 and 5 Global Land Cover, and the Digitized Ecosystem map of the Former Soviet Union) to evaluate the potential for error resulting from disparate vegetation structure and fuel consumption estimates. The examination of land cover maps showed that estimates of relative proportion of fire by ecosystem type varied substantially for the same year from map to map. Fuel consumption remains one of the main uncertainties in estimates of biomass burning emissions in Siberia. Accurate fuel consumption estimates are obtained in the course of fire experiments with pre- and post-fire biomass measuring. Our large-scale experiments carried out in the course of the FIRE BEAR (Fire Effects in the Boreal Eurasia Region) Project provided quantitative and qualitative data on ecosystem state and carbon emissions due to fires of known behavior in major forest types of Siberia that could be used to verify large-scale carbon emissions estimates. Global climate change is expected to result in increase of fire hazard and area burned, leading to impacts on global air

  10. Comprehensive laboratory measurements of biomass-burning emissions: 1. Emissions from Indonesian, African, and other fuels

    NASA Astrophysics Data System (ADS)

    Christian, T. J.; Kleiss, B.; Yokelson, R. J.; Holzinger, R.; Crutzen, P. J.; Hao, W. M.; Saharjo, B. H.; Ward, D. E.

    2003-12-01

    Trace gas and particle emissions were measured from 47 laboratory fires burning 16 regionally to globally significant fuel types. Instrumentation included the following: open-path Fourier transform infrared spectroscopy; proton transfer reaction mass spectrometry; filter sampling with subsequent analysis of particles with diameter <2.5 μm for organic and elemental carbon and other elements; and canister sampling with subsequent analysis by gas chromatography (GC)/flame ionization detector, GC/electron capture detector, and GC/mass spectrometry. The emissions of 26 compounds are reported by fuel type. The results include the first detailed measurements of the emissions from Indonesian fuels. Carbon dioxide, CO, CH4, NH3, HCN, methanol, and acetic acid were the seven most abundant emissions (in order) from burning Indonesian peat. Acetol (hydroxyacetone) was a major, previously unobserved emission from burning rice straw (21-34 g/kg). The emission factors for our simulated African fires are consistent with field data for African fires for compounds measured in both the laboratory and the field. However, the higher concentrations and more extensive instrumentation in this work allowed quantification of at least 10 species not previously quantified for African field fires (in order of abundance): acetaldehyde, phenol, acetol, glycolaldehyde, methylvinylether, furan, acetone, acetonitrile, propenenitrile, and propanenitrile. Most of these new compounds are oxygenated organic compounds, which further reinforces the importance of these reactive compounds as initial emissions from global biomass burning. A few high-combustion-efficiency fires emitted very high levels of elemental (black) carbon, suggesting that biomass burning may produce more elemental carbon than previously estimated.

  11. Transuranic Waste Burning Potential of Thorium Fuel in a Fast Reactor - 12423

    SciTech Connect

    Wenner, Michael; Franceschini, Fausto; Ferroni, Paolo; Sartori, Alberto; Ricotti, Marco

    2012-07-01

    Westinghouse Electric Company (referred to as 'Westinghouse' in the rest of this paper) is proposing a 'back-to-front' approach to overcome the stalemate on nuclear waste management in the US. In this approach, requirements to further the societal acceptance of nuclear waste are such that the ultimate health hazard resulting from the waste package is 'as low as reasonably achievable'. Societal acceptability of nuclear waste can be enhanced by reducing the long-term radiotoxicity of the waste, which is currently driven primarily by the protracted radiotoxicity of the transuranic (TRU) isotopes. Therefore, a transition to a more benign radioactive waste can be accomplished by a fuel cycle capable of consuming the stockpile of TRU 'legacy' waste contained in the LWR Used Nuclear Fuel (UNF) while generating waste which is significantly less radio-toxic than that produced by the current open U-based fuel cycle (once through and variations thereof). Investigation of a fast reactor (FR) operating on a thorium-based fuel cycle, as opposed to the traditional uranium-based is performed. Due to a combination between its neutronic properties and its low position in the actinide chain, thorium not only burns the legacy TRU waste, but it does so with a minimal production of 'new' TRUs. The effectiveness of a thorium-based fast reactor to burn legacy TRU and its flexibility to incorporate various fuels and recycle schemes according to the evolving needs of the transmutation scenario have been investigated. Specifically, the potential for a high TRU burning rate, high U-233 generation rate if so desired and low concurrent production of TRU have been used as metrics for the examined cycles. Core physics simulations of a fast reactor core running on thorium-based fuels and burning an external TRU feed supply have been carried out over multiple cycles of irradiation, separation and reprocessing. The TRU burning capability as well as the core isotopic content have been characterized

  12. Investigation of critical burning of fuel droplets. [monopropellants

    NASA Technical Reports Server (NTRS)

    Faeth, G. M.; Chanin, S.

    1974-01-01

    The steady combustion characteristics of droplets were considered in combustion chamber environments at various pressures, flow conditions, and ambient oxidizer concentrations for a number of hydrocarbon fuels. Using data obtained earlier, predicted gasification rates were within + or - 30% of measurements when the correction for convection was based upon average properties between the liquid surface and the flame around the droplet. Analysis was also completed for the open loop response of monopropellant droplets, based upon earlier strand combustion results. At the limit of large droplets, where the effect of flame curvature is small, the results suggest sufficient response to provide a viable mechanism for combustion instability in the frequency and droplet size range appropriate to practical combustors. Calculations are still in progress for a broader range of droplet sizes, including conditions where active combustion effects are small.

  13. Transmutation, Burn-Up and Fuel Fabrication Trade-Offs in Reduced-Moderation Water Reactor Thorium Fuel Cycles - 13502

    SciTech Connect

    Lindley, Benjamin A.; Parks, Geoffrey T.; Franceschini, Fausto

    2013-07-01

    Multiple recycle of long-lived actinides has the potential to greatly reduce the required storage time for spent nuclear fuel or high level nuclear waste. This is generally thought to require fast reactors as most transuranic (TRU) isotopes have low fission probabilities in thermal reactors. Reduced-moderation LWRs are a potential alternative to fast reactors with reduced time to deployment as they are based on commercially mature LWR technology. Thorium (Th) fuel is neutronically advantageous for TRU multiple recycle in LWRs due to a large improvement in the void coefficient. If Th fuel is used in reduced-moderation LWRs, it appears neutronically feasible to achieve full actinide recycle while burning an external supply of TRU, with related potential improvements in waste management and fuel utilization. In this paper, the fuel cycle of TRU-bearing Th fuel is analysed for reduced-moderation PWRs and BWRs (RMPWRs and RBWRs). RMPWRs have the advantage of relatively rapid implementation and intrinsically low conversion ratios. However, it is challenging to simultaneously satisfy operational and fuel cycle constraints. An RBWR may potentially take longer to implement than an RMPWR due to more extensive changes from current BWR technology. However, the harder neutron spectrum can lead to favourable fuel cycle performance. A two-stage fuel cycle, where the first pass is Th-Pu MOX, is a technically reasonable implementation of either concept. The first stage of the fuel cycle can therefore be implemented at relatively low cost as a Pu disposal option, with a further policy option of full recycle in the medium term. (authors)

  14. Methods and apparatus for burning fuel with low NO sub x formation

    SciTech Connect

    Schwartz, R.E.; Waibel, R.T.; Rodden, P.M.; Napier, S.O.

    1992-03-24

    This patent describes an improved burner apparatus for discharging a mixture of fuel and air into a furnace space wherein the mixture is burned and flue gases having low NO{sub x} content are formed. It comprises: a housing having an open end attached to the furnace space; means for introducing a controlled quantity of air into the housing and into the furnace space attached to the housing; primary mixer-nozzle means for mixing fuel with flue gases from the furnace space and discharging the resulting mixture into the furnace space disposed within the housing, the primary mixer-nozzle means including a pressurized fuel inlet for connection to a source of pressurized fuel and at least one flue gases inlet connection.

  15. Vortex combustor for low NOx emissions when burning lean premixed high hydrogen content fuel

    DOEpatents

    Steele, Robert C.; Edmonds, Ryan G.; Williams, Joseph T.; Baldwin, Stephen P.

    2009-10-20

    A trapped vortex combustor. The trapped vortex combustor is configured for receiving a lean premixed gaseous fuel and oxidant stream, where the fuel includes hydrogen gas. The trapped vortex combustor is configured to receive the lean premixed fuel and oxidant stream at a velocity which significantly exceeds combustion flame speed in a selected lean premixed fuel and oxidant mixture. The combustor is configured to operate at relatively high bulk fluid velocities while maintaining stable combustion, and low NOx emissions. The combustor is useful in gas turbines in a process of burning synfuels, as it offers the opportunity to avoid use of diluent gas to reduce combustion temperatures. The combustor also offers the possibility of avoiding the use of selected catalytic reaction units for removal of oxides of nitrogen from combustion gases exiting a gas turbine.

  16. Vortex combustor for low NOX emissions when burning lean premixed high hydrogen content fuel

    SciTech Connect

    Steele, Robert C; Edmonds, Ryan G; Williams, Joseph T; Baldwin, Stephen P

    2012-11-20

    A trapped vortex combustor. The trapped vortex combustor is configured for receiving a lean premixed gaseous fuel and oxidant stream, where the fuel includes hydrogen gas. The trapped vortex combustor is configured to receive the lean premixed fuel and oxidant stream at a velocity which significantly exceeds combustion flame speed in a selected lean premixed fuel and oxidant mixture. The combustor is configured to operate at relatively high bulk fluid velocities while maintaining stable combustion, and low NOx emissions. The combustor is useful in gas turbines in a process of burning synfuels, as it offers the opportunity to avoid use of diluent gas to reduce combustion temperatures. The combustor also offers the possibility of avoiding the use of selected catalytic reaction units for removal of oxides of nitrogen from combustion gases exiting a gas turbine.

  17. Burn-up and Operation Time of Fuel Elements Produced in IPEN

    NASA Astrophysics Data System (ADS)

    Tondin, Julio Benedito Marin; Filho, Tufic Madi

    2011-08-01

    The aim of this paper is to present the developed work along the operational and reliability tests of fuel elements produced in the Institute of Energetic and Nuclear Research, IPEN-CNEN/SP, from the 1980's. The study analyzed the U-235 burn evolution and the element remain in the research reactor IEA-R1. The fuel elements are of the type MTR (Material Testing Reactor), the standard with 18 plates and a 12-plate control, with a nominal mean enrichment of 20%.

  18. Reestablishing Open Rotor as an Option for Significant Fuel Burn Improvements

    NASA Technical Reports Server (NTRS)

    Van Zante, Dale

    2011-01-01

    A low-noise open rotor system is being tested in collaboration with General Electric and CFM International, a 50/50 joint company between Snecma and GE. Candidate technologies for lower noise will be investigated as well as installation effects such as pylon integration. Current test status is presented as well as future scheduled testing which includes the FAA/CLEEN test entry. Pre-test predictions show that Open Rotors have the potential for revolutionary fuel burn savings.

  19. Results of emissions testing while burning densified refuse derived fuel, Dordt College, Sioux Center, Iowa

    SciTech Connect

    Not Available

    1989-10-01

    Pacific Environmental Services, Inc. provided engineering and source testing services to the Council of Great Lake Governors to support their efforts in promoting the development and utilization of densified refuse derived fuels (d-RDF) and pelletized wastepaper fuels in small steam generating facilities. The emissions monitoring program was designed to provide a complete air emissions profile while burning various refuse derived fuels. The specific goal of this test program was to conduct air emissions tests at Dordt College located in Sioux Center, Iowa and to identify a relationship between fuel types and emission characteristics. The sampling protocol was carried out June 12 through June 20, 1989 on boiler {number sign}4. This unit had been previously modified to burn d-RDF. The boiler was not equipped with any type of air pollution control device so the emissions samples were collected from the boiler exhaust stack on the roof of the boilerhouse. The emissions that were sampled included: particulates; PM{sub 10} particulates; hydrochloric acid; dioxins; furans; polychlorinated biphenyls (PCB); metals and continuous monitors for CO, CO{sub 2}O{sub 2}SO{sub x}NO{sub x} and total hydrocarbons. Grab samples of the fuels were collected, composited and analyzed for heating value, moisture content, proximate and ultimate analysis, ash fusion temperature, bulk density and elemental ash analysis. Grab samples of the boiler ash were also collected and analyzed for total hydrocarbons total dioxins, total furans, total PCBs and heavy metals. 77 figs., 20 tabs.

  20. Recent view to the results of pulse tests in the IGR reactor with high burn-up fuel

    SciTech Connect

    Asmolov, V.; Yegorova, L.

    1996-03-01

    Testing of 43 fuel elements (13 fuel elements with high burn-up fuel, 10 fuel elements with preirradiated cladding and fresh fuel, and 20 non-irradiated fuel elements) was carried out in the IGR pulse reactor with a half width of the reactor power pulse of about 0.7 sec. Tests were conducted in capsules with no coolant flow and with standard initial conditions in the capsule of 20{degrees}C and 0.2 MPa. Two types of coolant were used: water and air. One purpose of the test program was to determine the thresholds and mechanisms of fuel rod failure under RIA conditions for VVER fuel rods over their entire exposure range, from zero to high burn-up. These failure thresholds are often used in safety analyses. The tests and analyses were designed to reveal the influence on fuel rod failure of (1) the mechanical properties of the cladding, (2) the pellet-to-cladding gap, (3) fuel burn-up, (4) fuel-to-coolant heat transfer, and other parameters. The resulting data base can also be used for validation of computer codes used for analyzing fuel rod behavior. Three types of test specimens were used in the tests, and diagrams of these specimens are shown in Fig. 1. {open_quotes}Type-C{close_quotes} specimens were re-fabricated from commercial fuel rods of the VVER-1000 type that had been subjected to many power cycles of operation in the Novovoronezh Nuclear Power Plant (NV NPP). {open_quotes}Type-D{close_quotes} specimens were fabricated from the same commercial fuel rods used above, but the high burn-up oxide fuel was removed from the cladding and was replaced with fresh oxide fuel pellets. {open_quotes}Type-D{close_quotes} specimens thus provided a means of separating the effects of the cladding and the oxide fuel pellets and were used to examine cladding effects only.

  1. ACFA 2020 - An FP7 project on active control of flexible fuel efficient aircraft configurations

    NASA Astrophysics Data System (ADS)

    Maier, R.

    2013-12-01

    This paper gives an overview about the project ACFA 2020 which is funded by the European Commission within the 7th framework program. The acronym ACFA 2020 stands for Active Control for Flexible Aircraft 2020. The project is dealing with the design of highly fuel efficient aircraft configurations and, in particular, on innovative active control concepts with the goal to reduce loads and structural weight. Major focus lays on blended wing body (BWB) aircraft. Blended wing body type aircraft configurations are seen as the most promising future concept to fulfill the so-called ACARE (Advisory Council for Aeronautics Research in Europe) vision 2020 goals in regards to reduce fuel consumption and external noise. The paper discusses in some detail the overall goals and how they are addressed in the workplan. Furthermore, the major achievements of the project are outlined and a short outlook on the remaining work is given.

  2. Thorium Fuel Options for Sustained Transuranic Burning in Pressurized Water Reactors - 12381

    SciTech Connect

    Rahman, Fariz Abdul; Lee, John C.; Franceschini, Fausto; Wenner, Michael

    2012-07-01

    As described in companion papers, Westinghouse is proposing the adoption of a thorium-based fuel cycle to burn the transuranics (TRU) contained in the current Used Nuclear Fuel (UNF) and transition towards a less radio-toxic high level waste. A combination of both light water reactors (LWR) and fast reactors (FR) is envisaged for the task, with the emphasis initially posed on their TRU burning capability and eventually to their self-sufficiency. Given the many technical challenges and development times related to the deployment of TRU burners fast reactors, an interim solution making best use of the current resources to initiate burning the legacy TRU inventory while developing and testing some technologies of later use is desirable. In this perspective, a portion of the LWR fleet can be used to start burning the legacy TRUs using Th-based fuels compatible with the current plants and operational features. This analysis focuses on a typical 4-loop PWR, with 17x17 fuel assembly design and TRUs (or Pu) admixed with Th (similar to U-MOX fuel, but with Th instead of U). Global calculations of the core were represented with unit assembly simulations using the Linear Reactivity Model (LRM). Several assembly configurations have been developed to offer two options that can be attractive during the TRU transmutation campaign: maximization of the TRU transmutation rate and capability for TRU multi-recycling, to extend the option of TRU recycling in LWR until the FR is available. Homogeneous as well as heterogeneous assembly configurations have been developed with various recycling schemes (Pu recycle, TRU recycle, TRU and in-bred U recycle etc.). Oxide as well as nitride fuels have been examined. This enabled an assessment of the potential for burning and multi-recycling TRU in a Th-based fuel PWR to compare against other more typical alternatives (U-MOX and variations thereof). Results will be shown indicating that Th-based PWR fuel is a promising option to multi-recycle and

  3. Thermal- and Fast-Spectrum Molten Salt Reactors for Actinide Burning and Fuel Production

    SciTech Connect

    Forsberg, Charles W

    2007-01-01

    In a molten salt reactor (MSR), the fuel is dissolved in a fluoride salt coolant. The technology was partly developed in the 1950s and 1960s. With changing goals for advanced reactors and new technologies, there is currently a renewed interest in MSRs. The new technologies include (1) Brayton power cycles (rather than steam cycles) that eliminate many of the historical challenges in building MSRs and (2) the conceptual development of several fast-spectrum MSRs that have large negative temperature and void coefficients, a unique safety characteristic not found in solid-fuel fast reactors. Earlier MSRs were thermal-neutron-spectrum reactors. Compared with solid-fueled reactors, MSR systems have lower fissile inventories, no radiation damage constraint on attainable fuel burnup, no spent nuclear fuel, no requirement to fabricate and handle solid fuel, and a single isotopic composition of fuel in the reactor. These and other characteristics may enable MSRs to have potentially unique capabilities and competitive economics for actinide burning and extending fuel resources. The status, unique characteristics, and recent worldwide advances in MSRs are described.

  4. Thermal- and fast-spectrum molten salt reactors for actinide burning and fuel production

    SciTech Connect

    Forsberg, Charles W.

    2007-07-01

    In a molten salt reactor (MSR), the fuel is dissolved in a fluoride salt coolant. The technology was partly developed in the 1950's and 1960's. With changing goals for advanced reactors and new technologies, there is currently a renewed interest in MSRs. The new technologies include (1) Brayton power cycles (rather than steam cycles) that eliminate many of the historical challenges in building MSRs and (2) the conceptual development of several fast-spectrum MSRs that have large negative temperature and void coefficients, a unique safety characteristic not found in solid-fuel fast reactors. Earlier MSRs were thermal-neutron-spectrum reactors. Compared with solid-fueled reactors, MSR systems have lower fissile inventories, no radiation damage constraint on attainable fuel burnup, no spent nuclear fuel, no requirement to fabricate and handle solid fuel, and a single isotopic composition of fuel in the reactor. These and other characteristics may enable MSRs to have potentially unique capabilities and competitive economics for actinide burning and extending fuel resources. The status, unique characteristics, and recent worldwide advances in MSRs are described. (author)

  5. Simulation of differential die-away instrument’s response to asymmetrically burned spent nuclear fuel

    DOE PAGES

    Martinik, Tomas; Henzl, Vladimir; Grape, Sophie; ...

    2015-03-04

    Here, previous simulation studies of Differential Die–Away (DDA) instrument’s response to active interrogation of spent nuclear fuel from a pressurized water reactor (PWR) yielded promising results in terms of its capability to accurately measure or estimate basic spent fuel assembly (SFA) characteristics, such as multiplication, initial enrichment (IE) and burn-up (BU) as well as the total plutonium content. These studies were however performed only for a subset of idealized SFAs with a symmetric BU with respect to its longitudinal axis. Therefore, to complement the previous results, additional simulations have been performed of the DDA instrument’s response to interrogation of asymmetricallymore » burned spent nuclear fuel in order to determine whether detailed assay of SFAs from all 4 sides will be necessary in real life applications or whether a cost and time saving single sided assay could be used to achieve results of similar quality as previously reported in case of symmetrically burned SFAs.« less

  6. Fail-safe system for activity cooled supersonic and hypersonic aircraft. [using liquid hydrogen fuel

    NASA Technical Reports Server (NTRS)

    Jones, R. A.; Braswell, D. O.; Richie, C. B.

    1975-01-01

    A fail-safe-system concept was studied as an alternative to a redundant active cooling system for supersonic and hypersonic aircraft which use the heat sink of liquid-hydrogen fuel for cooling the aircraft structure. This concept consists of an abort maneuver by the aircraft and a passive thermal protection system (TPS) for the aircraft skin. The abort manuever provides a low-heat-load descent from normal cruise speed to a lower speed at which cooling is unnecessary, and the passive TPS allows the aircraft skin to absorb the abort heat load without exceeding critical skin temperature. On the basis of results obtained, it appears that this fail-safe-system concept warrants further consideration, inasmuch as a fail-safe system could possibly replace a redundant active cooling system with no increase in weight and would offer other potential advantages.

  7. Heat Transfer and Thermal Stability of Alternative Aircraft Fuels. Volume 2. Appendices.

    DTIC Science & Technology

    1983-11-01

    AD-A137 405 HEAT TRANSFER AND THERMAL STABILITY OF ALTERNATIVE s AIRCRAFT FUELS VOLUME 2.-(U) PRATT AND WHITNEY AIRCRAFT GROUP WEST PALM BEACH FL...Whitney Aircraft PE63724N Government Products Division Project No. Z0838 P. O. Box 2691, West Palm Beach, FL 33402 Work Unit NAPC-617 11. CONTROLLING...Division, located in Palm Beach County, Florida. The work ws conducted under Contract No. N00140-80-C-0097, Lot III, for the Naval Air Propulsion Center

  8. Experimental Study of the Stability of Aircraft Fuels at Elevated Temperatures

    NASA Technical Reports Server (NTRS)

    Vranos, A.; Marteney, P. J.

    1980-01-01

    An experimental study of fuel stability was conducted in an apparatus which simulated an aircraft gas turbine fuel system. Two fuels were tested: Jet A and Number 2 Home Heating oil. Jet A is an aircraft gas turbine fuel currently in wide use. No. 2HH was selected to represent the properties of future turbine fuels, particularly experimental Reference Broad Specification, which, under NASA sponsorship, was considered as a possible next-generation fuel. Tests were conducted with varying fuel flow rates, delivery pressures and fuel pretreatments (including preheating and deoxygenation). Simulator wall temperatures were varied between 422K and 672K at fuel flows of 0.022 to 0.22 Kg/sec. Coking rate was determined at four equally-spaced locations along the length of the simulator. Fuel samples were collected for infrared analysis. The dependence of coking rate in Jet A may be correlated with surface temperature via an activation energy of 9 to 10 kcal/mole, although the results indicate that both bulk fluid and surface temperature affect the rate of decomposition. As a consequence, flow rate, which controls bulk temperature, must also be considered. Taken together, these results suggest that the decomposition reactions are initiated on the surface and continue in the bulk fluid. The coking rate data for No. 2 HH oil are very highly temperature dependent above approximately 533K. This suggests that bulk phase reactions can become controlling in the formation of coke.

  9. Thermal management for a Mach 5 cruise aircraft using endothermic fuel

    NASA Technical Reports Server (NTRS)

    Petley, Dennis H.; Jones, Stuart C.

    1990-01-01

    The present thermal management system for a carrier-based Mach 5 cruise-capable aircraft whose propulsion system does not entail cryogenic fuels is predicated on the use of the catalytic endothermic reaction of a petroleum-derived hydrocarbon fuel as the heat sink for engine cooling. The insulation of engine flowpath surfaces reduces cooling requirements. The primary elements of this closed-cycle cooling system are a fuel preheater, a catalytic fuel reactor, and engine wall-cooling panels; a silicone-based liquid polymer is used as the coolant. Structural, weight, and thermal analysis results are presented for each of the primary components.

  10. The adaptation of sustainable biojet fuels and its effect on aircraft engine maintenance

    NASA Astrophysics Data System (ADS)

    Mohd Noh, H.; Rodrigo, G. A.; Rahman, N. A. Abdul

    2016-10-01

    Aviation industries are looking into several resources for renewable and sustainable energy. Among those attention is focused in biojet fuel. This paper engages the issue of biojet fuel emissions that increase the environmental concern in the air transport sector. The paper presents the use of biojet fuel and its effect on aircraft engine maintenance through preliminary data collections, and a review of its development process in operations for time and goal. As conclusion, airlines management needs to adapt and adopt the transition to alternative fuels, especially given the global biofuel trend emerging due to the authority approval.

  11. Development of an experiment for determining the autoignition characteristics of aircraft-type fuels

    NASA Technical Reports Server (NTRS)

    Spadaccini, L. J.

    1977-01-01

    An experimental test apparatus was developed to determine the autoignition characteristics of aircraft-type fuels in premixing prevaporizing passages at elevated temperatures and pressures. The experiment was designed to permit independent variation and evaluation of the experimental variables of pressure, temperature, flow rate, and fuel-air ratio. A comprehensive review of the autoignition literature is presented. Performance verification tests consisting of measurements of the ignition delay times for several lean fuel-air mixture ratios were conducted using Jet-A fuel at inlet air temperatures in the range 600 K to 900 K and pressures in the range 9 atm to 30 atm.

  12. Evaluation of advanced lift concepts and potential fuel conservation for short-haul aircraft

    NASA Technical Reports Server (NTRS)

    Sweet, H. S.; Renshaw, J. H.; Bowden, M. K.

    1975-01-01

    The effect of different field lengths, cruise requirements, noise level, and engine cycle characteristics on minimizing fuel consumption and minimizing operating cost at high fuel prices were evaluated for some advanced short-haul aircraft. The conceptual aircraft were designed for 148 passengers using the upper surface-internally blown jet flap, the augmentor wing, and the mechanical flap lift systems. Advanced conceptual STOL engines were evaluated as well as a near-term turbofan and turboprop engine. Emphasis was given to designs meeting noise levels equivalent to 95-100 EPNdB at 152 m (500 ft) sideline.

  13. Solid Fuel Burning in Steady, Strained, Premixed Flow Fields: The Graphite/Air/Methane System

    NASA Technical Reports Server (NTRS)

    Egolfopoulos, Fokion N.; Wu, Ming-Shin (Technical Monitor)

    2000-01-01

    A detailed numerical investigation was conducted on the simultaneous burning of laminar premixed CH4/air flames and solid graphite in a stagnation flow configuration. The graphite and methane were chosen for this model, given that they are practical fuels and their chemical kinetics are considered as the most reliable ones among solid and hydrocarbon fuels, respectively. The simulation was performed by solving the quasi-one-dimensional equations of mass, momentum, energy, and species. The GRI 2.1 scheme was used for the gas-phase kinetics, while the heterogeneous kinetics were described by a six-step mechanism including stable and radical species. The effects of the graphite surface temperature, the gas-phase equivalence ratio, and the aerodynamic strain rate on the graphite burning rate and NO, production and destruction mechanisms were assessed. Results indicate that as the graphite temperature increases, its burning rate as well as the NO, concentration increase. Furthermore, it was found that by increasing the strain rate, the graphite burning rate increases as a result of the augmented supply of the gas-phase reactants towards the surface, while the NO, concentration decreases as a result of the reduced residence time. The effect of the equivalence ratio on both the graphite burning rate and NO, concentration was found to be non-monotonic and strongly dependent on the graphite temperature. Comparisons between results obtained for a graphite and a chemically inert surface revealed that the chemical activity of the graphite surface can result to the reduction of NO through reactions of the CH3, CH2, CH, and N radicals with NO.

  14. Coated Particle Fuel and Deep Burn Program Monthly Highlights March 2011

    SciTech Connect

    Snead, Lance Lewis; Bell, Gary L; Besmann, Theodore M

    2011-04-01

    During FY 2011 the CP & DB Program will report Highlights on a monthly basis, but will no longer produce Quarterly Progress Reports. Technical details that were previously included in the quarterly reports will be included in the appropriate Milestone Reports that are submitted to FCRD Program Management. These reports will also be uploaded to the Deep Burn website. The Monthly Highlights report for February 2011, ORNL/TM-2011/71, was distributed to program participants on March 8, 2011. As reported previously, the final Quarterly for FY 2010, Deep Burn Program Quarterly Report for July - September 2010, ORNL/TM-2010/301, was announced to program participants and posted to the website on December 28, 2010. This report discusses the following: (1) Thermochemical Data and Model Development - (a) Thermochemical Modeling, (b) Thermomechanical Behavior, (c) Actinide and Fission Product Transport, (d) Radiation Damage and Properties; (2) TRU (transuranic elements) TRISO (tri-structural isotropic) Development - (a) TRU Kernel Development, (b) Coating Development; (3) Advanced TRISO Applications - Metal Matrix Fuels for LWR; (4) LWR Fully Ceramic Fuel - (a) FCM Fabrication Development, (b) FCM Irradiation Testing; and (5) Fuel Performance and Analytical Analysis - Fuel Performance Modeling.

  15. Coated Particle Fuel and Deep Burn Program Monthly Highlights February 2011

    SciTech Connect

    Snead, Lance Lewis; Bell, Gary L; Besmann, Theodore M

    2011-03-01

    During FY 2011 the CP & DB Program will report Highlights on a monthly basis, but will no longer produce Quarterly Progress Reports. Technical details that were previously included in the quarterly reports will be included in the appropriate Milestone Reports that are submitted to FCRD Program Management. These reports will also be uploaded to the Deep Burn website. The Monthly Highlights report for January 2010, ORNL/TM-2011/30, was distributed to program participants on February 8, 2011. As reported previously, the final Quarterly for FY 2010, Deep Burn Program Quarterly Report for July - September 2010, ORNL/TM-2010/301, was announced to program participants and posted to the website on December 28, 2010. This report discusses the following: (1) Thermochemical Data and Model Development - (a) Thermochemical Modeling, (b) Actinide and Fission Product Transport, (c) Radiation Damage and Properties; (2) TRU (transuranic elements) TRISO (tri-structural isotropic) Development - (a) TRU Kernel Development, (b) Coating Development; (3) Advanced TRISO Applications - Metal Matrix Fuels for LWR; (4) LWR Fully Ceramic Fuel - (a) FCM Fabrication Development, (b) FCM Irradiation Testing; and (5) Fuel Performance and Analytical Analysis - Fuel Performance Modeling.

  16. Long-term tradeoffs between nuclear- and fossil-fuel burning

    SciTech Connect

    Krakowski, R.A.

    1996-12-31

    A global energy/economics/environmental (E{sup 3}) model has been adapted with a nuclear energy/materials model to understand better {open_quotes}top-level{close_quotes}, long-term trade offs between civilian nuclear power, nuclear-weapons proliferation, fossil-fuel burning, and global economic welfare. Using a {open_quotes}business-as-usual{close_quotes} (BAU) point-of-departure case, economic, resource, proliferation-risk implications of plutonium recycle in LAIRs, greenhouse-gas-mitigating carbon taxes, and a range of nuclear energy costs (capital and fuel) considerations have been examined. After describing the essential elements of the analysis approach being developed to support the Los Alamos Nuclear Vision Project, preliminary examples of parametric variations about the BAU base-case scenario are presented. The results described herein represent a sampling from more extensive results collected in a separate report. The primary motivation here is: (a) to compare the BAU basecase with results from other studies; (b) to model on a regionally resolved global basis long-term (to year {approximately}2100) evolution of plutonium accumulation in a variety of forms under a limited range of fuel-cycle scenarios; and (c) to illustrate a preliminary connectivity between risks associated with nuclear proliferation and fossil-fuel burning (e.g., greenhouse-gas accumulations).

  17. EBSD and TEM Characterization of High Burn-up Mixed Oxide Fuel

    SciTech Connect

    Teague, Melissa C.; Gorman, Brian P.; Miller, Brandon D.; King, Jeffrey

    2014-01-01

    Understanding and studying the irradiation behavior of high burn-up oxide fuel is critical to licensing of future fast breeder reactors. Advancements in experimental techniques and equipment are allowing for new insights into previously irradiated samples. In this work dual column focused ion beam (FIB)/scanning electron microscope (SEM) was utilized to prepared transmission electron microscope samples from mixed oxide fuel with a burn-up of 6.7% FIMA. Utilizing the FIB/SEM for preparation resulted in samples with a dose rate of <0.5 mRem/h compared to approximately 1.1 R/h for a traditionally prepared TEM sample. The TEM analysis showed that the sample taken from the cooler rim region of the fuel pellet had approximately 2.5x higher dislocation density than that of the sample taken from the mid-radius due to the lower irradiation temperature of the rim. The dual column FIB/SEM was additionally used to prepared and serially slice approximately 25 um cubes. High quality electron back scatter diffraction (EBSD) were collected from the face at each step, showing, for the first time, the ability to obtain EBSD data from high activity irradiated fuel.

  18. Scheduled civil aircraft emission inventories for 1992: Database development and analysis

    NASA Technical Reports Server (NTRS)

    Baughcum, Steven L.; Tritz, Terrance G.; Henderson, Stephen C.; Pickett, David C.

    1996-01-01

    This report describes the development of a three-dimensional database of aircraft fuel burn and emissions (fuel burned, NOx, CO, and hydrocarbons) from scheduled commercial aircraft for each month of 1992. The seasonal variation in aircraft emissions was calculated for selected regions (global, North America, Europe, North Atlantic, and North Pacific). A series of parametric calculations were done to quantify the possible errors introduced from making approximations necessary to calculate the global emission inventory. The effects of wind, temperature, load factor, payload, and fuel tankering on fuel burn were evaluated to identify how they might affect the accuracy of aircraft emission inventories. These emissions inventories are available for use by atmospheric scientists conducting the Atmospheric Effects of Aviation Project (AEAP) modeling studies. Fuel burned and emissions of nitrogen oxides (NOx as N02), carbon monoxide, and hydrocarbons have been calculated on a 1 degree latitude x 1 degree longitude x 1 kilometer altitude grid and delivered to NASA as electronic files.

  19. Deep Burn Fuel Cycle Integration: Evaluation of Two-Tier Scenarios

    SciTech Connect

    S. Bays; H. Zhang; M. Pope

    2009-05-01

    The use of a deep burn strategy using VHTRs (or DB-MHR), as a means of burning transuranics produced by LWRs, was compared to performing this task with LWR MOX. The spent DB-MHR fuel was recycled for ultimate final recycle in fast reactors (ARRs). This report summarizes the preliminary findings of the support ratio (in terms of MWth installed) between LWRs, DB-MHRs and ARRs in an equilibrium “two-tier” fuel cycle scenario. Values from literature were used to represent the LWR and DB-MHR isotopic compositions. A reactor physics simulation of the ARR was analyzed to determine the effect that the DB-MHR spent fuel cooling time on the ARR transuranic consumption rate. These results suggest that the cooling time has some but not a significant impact on the ARRs conversion ratio and transuranic consumption rate. This is attributed to fissile worth being derived from non-fissile or “threshold-fissioning” isotopes in the ARR’s fast spectrum. The fraction of installed thermal capacity of each reactor in the DB-MHR 2-tier fuel cycle was compared with that of an equivalent MOX 2-tier fuel cycle, assuming fuel supply and demand are in equilibrium. The use of DB-MHRs in the 1st-tier allows for a 10% increase in the fraction of fleet installed capacity of UO2-fueled LWRs compared to using a MOX 1st-tier. Also, it was found that because the DB-MHR derives more power per unit mass of transuranics charged to the fresh fuel, the “front-end” reprocessing demand is less than MOX. Therefore, more fleet installed capacity of DB-MHR would be required to support a given fleet of UO2 LWRs than would be required of MOX plants. However, the transuranic deep burn achieved by DB-MHRs reduces the number of fast reactors in the 2nd-tier to support the DB-MHRs “back-end” transuranic output than if MOX plants were used. Further analysis of the relative costs of these various types of reactors is required before a comparative study of these options could be considered complete.

  20. 26 CFR 48.4041-4 - Application of tax on sales of liquid for use as fuel in aircraft in noncommercial aviation.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... as fuel in aircraft in noncommercial aviation. 48.4041-4 Section 48.4041-4 Internal Revenue INTERNAL... aircraft in noncommercial aviation. (a) In general. The taxes imposed by subparagraphs (1)(A) and (2)(A) of... operator of an aircraft, for use as a fuel in the aircraft in noncommercial aviation. (b) Liability of...

  1. 26 CFR 48.4041-4 - Application of tax on sales of liquid for use as fuel in aircraft in noncommercial aviation.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... fuel in aircraft in noncommercial aviation. 48.4041-4 Section 48.4041-4 Internal Revenue INTERNAL... aircraft in noncommercial aviation. (a) In general. The taxes imposed by subparagraphs (1)(A) and (2)(A) of... operator of an aircraft, for use as a fuel in the aircraft in noncommercial aviation. (b) Liability of...

  2. 26 CFR 48.4041-4 - Application of tax on sales of liquid for use as fuel in aircraft in noncommercial aviation.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... as fuel in aircraft in noncommercial aviation. 48.4041-4 Section 48.4041-4 Internal Revenue INTERNAL... aircraft in noncommercial aviation. (a) In general. The taxes imposed by subparagraphs (1)(A) and (2)(A) of... operator of an aircraft, for use as a fuel in the aircraft in noncommercial aviation. (b) Liability of...

  3. 26 CFR 48.4041-4 - Application of tax on sales of liquid for use as fuel in aircraft in noncommercial aviation.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... as fuel in aircraft in noncommercial aviation. 48.4041-4 Section 48.4041-4 Internal Revenue INTERNAL... aircraft in noncommercial aviation. (a) In general. The taxes imposed by subparagraphs (1)(A) and (2)(A) of... operator of an aircraft, for use as a fuel in the aircraft in noncommercial aviation. (b) Liability of...

  4. Measurements of nitrous acid in commercial aircraft exhaust at the Alternative Aviation Fuel Experiment.

    PubMed

    Lee, Ben H; Santoni, Gregory W; Wood, Ezra C; Herndon, Scott C; Miake-Lye, Richard C; Zahniser, Mark S; Wofsy, Steven C; Munger, J William

    2011-09-15

    The Alternative Aviation Fuel Experiment (AAFEX), conducted in January of 2009 in Palmdale, California, quantified aerosol and gaseous emissions from a DC-8 aircraft equipped with CFM56-2C1 engines using both traditional and synthetic fuels. This study examines the emissions of nitrous acid (HONO) and nitrogen oxides (NO(x) = NO + NO(2)) measured 145 m behind the grounded aircraft. The fuel-based emission index (EI) for HONO increases approximately 6-fold from idle to takeoff conditions but plateaus between 65 and 100% of maximum rated engine thrust, while the EI for NO(x) increases continuously. At high engine power, NO(x) EI is greater when combusting traditional (JP-8) rather than Fischer-Tropsch fuels, while HONO exhibits the opposite trend. Additionally, hydrogen peroxide (H(2)O(2)) was identified in exhaust plumes emitted only during engine idle. Chemical reactions responsible for emissions and comparison to previous measurement studies are discussed.

  5. Fuel modeling at high burn-up: recent development of the GERMINAL code

    NASA Astrophysics Data System (ADS)

    Melis, J.-C.; Piron, J.-P.; Roche, L.

    1993-09-01

    In the frame of research and development on fast breeder reactors fuels, CEA/DEC is developing the computer code GERMINAL to study fuel pin thermal and mechanical behaviour during steady-state and accidental conditions. The development of the GERMINAL 1 code is foreseen in two steps: (1) The GERMINAL 1-1 version which is presently delivered fully documented with a physical qualification guaranteed up to 8 at%. (2) The GERMINAL 1-2 version which, in addition to what is presently treated in GERMINAL 1-1, includes the treatment of high burn-up effects on the the fission gas release and the fuel-clad interface (called JOG). The validation of GERMINAL 1-2 is presently in progress and will include specific experiments (JOG tests) performed in the CABRI reactor.

  6. An economic analysis of using alternative fuels in a mass burn boiler.

    PubMed

    Kaylen, Michael S

    2005-11-01

    In this study the economic feasibility of using alternative fuels in a mass burn boiler for a chemical plant in northeastern Missouri is analyzed. The key consideration is whether biomass (switchgrass and crop residues) is economically preferred to other available fuels. Research reveals an abundance of alternative fuels for which the plant would receive a tipping fee, including municipal solid waste and used tires. Since the plant would have to pay for biomass, it does not appear in the optimal solution. An economic optimization model shows the marginal cost to the plant of using biomass would increase as more biomass is used, displacing quantities of more valuable (in terms of tipping fees per BTU) waste materials.

  7. Test burning of tire-derived fuel in solid fuel combustors

    SciTech Connect

    Dennis, D.C.

    1994-12-31

    This study was commissioned to determine the overall viability of utilizing scrap tire chips, known as tire-derived fuel (TDF), as a supplemental fuel in conventional coal-fired boilers. The study involved actual tests at Monsanto Company`s W.G. Krummrich Plant in Sauget, Illinois, as well as general extrapolations as to the feasibility of using TDF at other sites. This report will show that TDF can be an excellent supplemental fuel supply, providing a cost-effective fuel source while helping to alleviate the dilemma of scrap tire disposal.

  8. Rates of post-fire vegetation recovery and fuel accumulation as a function of burn severity and time-since-burn in four western U.S. ecosystems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vegetation recovery and fuel accumulation rates following wildfire are useful measures of ecosystem resilience, yet few studies have quantified these variables over 10 years post-fire. Conventional wisdom is that recovery time to pre-fire condition will be slower as a function of burn severity, as i...

  9. The influence of fuel mass load, oxygen supply and burning rate on emission factor and size distribution of carbonaceous particulate matter from indoor corn straw burning

    PubMed Central

    Shen, Guofeng; Xue, Miao; Wei, Siye; Chen, Yuanchen; Wang, Bing; Wang, Rong; Shen, Huizhong; Li, Wei; Zhang, Yanyan; Huang, Ye; Chen, Han; Wei, Wen; Zhao, Qiuyue; Li, Bin; Wu, Haisuo; Tao, Shu

    2014-01-01

    The uncertainty in emission estimation is strongly associated with the variation in emission factor which could be influenced by a variety of factors, like fuel property, stove type, fire management and even methods used in measurements. The impacts of these factors were usually complicated and often interacted with each other. In the present study, controlled burning experiments were conducted to investigate the influence of fuel mass load, air supply and burning rate on the emission of carbonaceous particulate matter (PM) from indoor corn straw burning. Their impacts on PM size distribution were also studied. The results showed that EFs of PM (EFPM), organic carbon (EFOC) and element carbon (EFEC) was independent of the fuel mass load. The differences among them under different burning rates or air supply amounts were also found to be insignificant (p > 0.05) in the tested circumstances. PM from the indoor corn straw burning was dominated by fine PM, and PM with diameter less than 2.1 μm contributed about 86.4±3.9% of the total. The size distribution of PM was also influenced by the burning rate and changed air supply conditions. On average, EFPM, EFOC and EFEC for corn straw burned in a residential cooking stove were 3.84±1.02, 0.846±0.895 and 0.391±0.350 g/kg, respectively. EFPM, EFOC and EFEC were found to be positively correlated with each other, but they were not significantly correlated with EF of co-emitted CO, suggesting a special attention should be paid to the use of CO acting as a surrogate for other incomplete pollutants. PMID:23923424

  10. Telemetry system for evaluation of burn protection in full-scale fuel fire manikin exposures

    NASA Astrophysics Data System (ADS)

    Piergallini, J. R.; Stoll, A. M.

    1980-05-01

    An eighteen channel PAM/FM (Pulse Amplitude Modulated/Frequency Modulated) telemetry system was developed for measuring temperature rise on the surface of a manikin beneath protective clothing for full-scale fuel fire exposures in completely enveloping flames. Thermistors are used as temperature sensors at various locations on a manikin surface and backed by material of known thermal properties in order to correlate temperature rise with skin burn damage. The transmitted signals are recorded on analog magnetic tape and converted to a digital format for computer analysis. The clothed manikin is passed through an aviation gasoline fire for three seconds with the telemetry system recording data during this period. Temperatures are analyzed at 0, 1, 2 and 3-second intervals with voltage outputs from the thermistors being converted to resistance readings and temperature readings by equations developed from curves of thermistor characteristics. Experimental results with respect to burn prediction are in agreement with data obtained by analysis of vesicant papers calibrated radiometrically to correlate with temperature-time effects productive of burns in living tissue. To date, 12 full-scale fuel fire tests have been conducted using the telemetry system and the performance of this system has exceeded original expectations in many respects such as sensitivity, accuracy and freedom from interference by ionizing gases within the flames.

  11. Fuel containment and damage tolerance for large composite primary aircraft structures. Phase 1: Testing

    NASA Technical Reports Server (NTRS)

    Sandifer, J. P.

    1983-01-01

    Technical problems associated with fuel containment and damage tolerance of composite material wings for transport aircraft were identified. The major tasks are the following: (1) the preliminary design of damage tolerant wing surface using composite materials; (2) the evaluation of fuel sealing and lightning protection methods for a composite material wing; and (3) an experimental investigation of the damage tolerant characteristics of toughened resin graphite/epoxy materials. The test results, the test techniques, and the test data are presented.

  12. Fuel level sensor based on polymer optical fiber Bragg gratings for aircraft applications

    NASA Astrophysics Data System (ADS)

    Marques, C. A. F.; Pospori, A.; Sáez-Rodríguez, D.; Nielsen, K.; Bang, O.; Webb, D. J.

    2016-04-01

    Safety in civil aviation is increasingly important due to the increase in flight routes and their more challenging nature. Like other important systems in aircraft, fuel level monitoring is always a technical challenge. The most frequently used level sensors in aircraft fuel systems are based on capacitive, ultrasonic and electric techniques, however they suffer from intrinsic safety concerns in explosive environments combined with issues relating to reliability and maintainability. In the last few years, optical fiber liquid level sensors (OFLLSs) have been reported to be safe and reliable and present many advantages for aircraft fuel measurement. Different OFLLSs have been developed, such as the pressure type, float type, optical radar type, TIR type and side-leaking type. Amongst these, many types of OFLLSs based on fiber gratings have been demonstrated. However, these sensors have not been commercialized because they exhibit some drawbacks: low sensitivity, limited range, long-term instability, or limited resolution. In addition, any sensors that involve direct interaction of the optical field with the fuel (either by launching light into the fuel tank or via the evanescent field of a fiber-guided mode) must be able to cope with the potential build up of contamination - often bacterial - on the optical surface. In this paper, a fuel level sensor based on microstructured polymer optical fiber Bragg gratings (mPOFBGs), including poly (methyl methacrylate) (PMMA) and TOPAS fibers, embedded in diaphragms is investigated in detail. The mPOFBGs are embedded in two different types of diaphragms and their performance is investigated with aviation fuel for the first time, in contrast to our previous works, where water was used. Our new system exhibits a high performance when compared with other previously published in the literature, making it a potentially useful tool for aircraft fuel monitoring.

  13. Emission characteristics for polycyclic aromatic hydrocarbons from solid fuels burned in domestic stoves in rural China

    PubMed Central

    SHEN, Guofeng; TAO, Shu; Chen, Yuanchen; Zhang, Yanyan; Wei, Siye; Xue, Miao; Wang, Bin; WANG, Rong; LV, Yan; LI, Wei; SHEN, Huizhong; HUANG, Ye; CHEN, Han

    2014-01-01

    Emission characterization of polycyclic aromatic hydrocarbons (PAHs) from residential combustion of crop residues, woody material, coal, and biomass pellets in domestic stoves in rural China are compared in term of emission factors (EFs), influencing factors, composition profiles, isomer ratios and phase distributions. The EFs of PAHs vary by two orders of magnitude among fuel types suggesting that a detailed fuel categorization is useful in the development of an emission inventory and potential in emission abatement of PAHs by replacing dirty fuels with relatively cleaner ones. The influence of fuel moisture in biomass burning is non-linear. Biofuels with very low moisture display relatively high emissions as do fuels with very high moisture. Bituminous coals and brushwood yield relatively large fractions of high molecular PAHs. The emission factor of Benzo(a)pyrene equivalent quantity for raw bituminous coal is as high as 52 mg/kg, which is 1–2 orders of magnitude higher than the other fuels. For source diagnosis, high molecular weight isomers are more informative than low molecular weight ones and multiple ratios could be used together whenever possible. PMID:24245776

  14. Emission characteristics for polycyclic aromatic hydrocarbons from solid fuels burned in domestic stoves in rural China.

    PubMed

    Shen, Guofeng; Tao, Shu; Chen, Yuanchen; Zhang, Yanyan; Wei, Siye; Xue, Miao; Wang, Bin; Wang, Rong; Lu, Yan; Li, Wei; Shen, Huizhong; Huang, Ye; Chen, Han

    2013-12-17

    Emission characterization of polycyclic aromatic hydrocarbons (PAHs) from residential combustion of crop residues, woody material, coal, and biomass pellets in domestic stoves in rural China are compared in term of emission factors (EFs), influencing factors, composition profiles, isomer ratios and phase distributions. The EFs of PAHs vary by 2 orders of magnitude among fuel types suggesting that a detailed fuel categorization is useful in the development of an emission inventory and potential in emission abatement of PAHs by replacing dirty fuels with relatively cleaner ones. The influence of fuel moisture in biomass burning is nonlinear. Biofuels with very low moisture display relatively high emissions as do fuels with very high moisture. Bituminous coals and brushwood yield relatively large fractions of high molecular PAHs. The emission factor of benzo(a)pyrene equivalent quantity for raw bituminous coal is as high as 52 mg/kg, which is 1-2 orders of magnitude higher than the other fuels. For source diagnosis, high molecular weight isomers are more informative than low molecular weight ones and multiple ratios could be used together whenever possible.

  15. Using Coupled Mesoscale Experiments and Simulations to Investigate High Burn-Up Oxide Fuel Thermal Conductivity

    NASA Astrophysics Data System (ADS)

    Teague, Melissa C.; Fromm, Bradley S.; Tonks, Michael R.; Field, David P.

    2014-12-01

    Nuclear energy is a mature technology with a small carbon footprint. However, work is needed to make current reactor technology more accident tolerant and to allow reactor fuel to be burned in a reactor for longer periods of time. Optimizing the reactor fuel performance is essentially a materials science problem. The current understanding of fuel microstructure have been limited by the difficulty in studying the structure and chemistry of irradiated fuel samples at the mesoscale. Here, we take advantage of recent advances in experimental capabilities to characterize the microstructure in 3D of irradiated mixed oxide (MOX) fuel taken from two radial positions in the fuel pellet. We also reconstruct these microstructures using Idaho National Laboratory's MARMOT code and calculate the impact of microstructure heterogeneities on the effective thermal conductivity using mesoscale heat conduction simulations. The thermal conductivities of both samples are higher than the bulk MOX thermal conductivity because of the formation of metallic precipitates and because we do not currently consider phonon scattering due to defects smaller than the experimental resolution. We also used the results to investigate the accuracy of simple thermal conductivity approximations and equations to convert 2D thermal conductivities to 3D. It was found that these approximations struggle to predict the complex thermal transport interactions between metal precipitates and voids.

  16. Design, fabrication and testing of a liquid hydrogen fuel tank for a long duration aircraft

    NASA Astrophysics Data System (ADS)

    Mills, Gary L.; Buchholtz, Brian; Olsen, Al

    2012-06-01

    Liquid hydrogen has distinct advantages as an aircraft fuel. These include a specific heat of combustion 2.8 times greater than gasoline or jet fuel and zero carbon emissions. It can be utilized by fuel cells, turbine engines and internal combustion engines. The high heat of combustion is particularly important in the design of long endurance aircraft with liquid hydrogen enabling cruise endurance of several days. However, the mass advantage of the liquid hydrogen fuel will result in a mass advantage for the fuel system only if the liquid hydrogen tank and insulation mass is a small fraction of the hydrogen mass. The challenge is producing a tank that meets the mass requirement while insulating the cryogenic liquid hydrogen well enough to prevent excessive heat leak and boil off. In this paper, we report on the design, fabrication and testing of a liquid hydrogen fuel tank for a prototype high altitude long endurance (HALE) demonstration aircraft. Design options on tank geometry, tank wall material and insulation systems are discussed. The final design is an aluminum sphere insulated with spray on foam insulation (SOFI). Several steps and organizations were involved in the tank fabrication and test. The tank was cold shocked, helium leak checked and proof pressure tested. The overall thermal performance was verified with a boil off test using liquid hydrogen.

  17. 40 CFR 63.1217 - What are the standards for liquid fuel boilers that burn hazardous waste?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... boilers that burn hazardous waste? 63.1217 Section 63.1217 Protection of Environment ENVIRONMENTAL... Hazardous Waste Combustors Emissions Standards and Operating Limits for Solid Fuel Boilers, Liquid Fuel Boilers, and Hydrochloric Acid Production Furnaces § 63.1217 What are the standards for liquid...

  18. Flame front speed and onset of instability in the burning of inclined thin solid fuel samples

    NASA Astrophysics Data System (ADS)

    Comas, Bruna; Pujol, Toni

    2013-12-01

    We focus on the front propagation of diffusive flames obtained from the downward burning of inclined thermally thin solid fuels. This process consists of a pyrolysis reaction in the solid-phase and a combustion reaction in the gas phase. The solid-phase model is based on two coupled one-dimensional equations of temperature and solid density. We reduce the system into a single one-dimensional equation from which we obtain an analytical expression for the flame front speed. This expression may be understood as an upper bound of the burning spread rate in inclined samples. The gas-phase model is based on four coupled two-dimensional equations. These are employed to derive a criterion for determining the critical inclination angle beyond which the flame behavior becomes unstable. The comparison with the experiments confirms the validity of our predictions.

  19. Feasibility of a nuclear gauge for fuel quantity measurement aboard aircraft

    NASA Technical Reports Server (NTRS)

    Signh, J. J.; Mall, G. H.; Sprinkle, D. R.; Chegini, H.

    1986-01-01

    Capacitance fuel gauges have served as the basis for fuel quantity indicating systems in aircraft for several decades. However, there have been persistent reports by the airlines that these gauges often give faulty indications due to microbial growth and other contaminants in the fuel tanks. This report describes the results of a feasibility study of using gamma ray attenuation as the basis for measuring fuel quantity in the tanks. Studies with a weak Am-241 59.5-keV radiation source indicate that it is possible to continuously monitor the fuel quantity in the tanks to an accuracy of better than 1 percent. These measurements also indicate that there are easily measurable differences in the physical properties and resultant attenuation characteristics of JP-4, JP-5, and Jet A fuels. The experimental results, along with a suggested source-detector geometrical configuration are described.

  20. Characterisation of a hybrid, fuel-cell-based propulsion system for small unmanned aircraft

    NASA Astrophysics Data System (ADS)

    Verstraete, D.; Lehmkuehler, K.; Gong, A.; Harvey, J. R.; Brian, G.; Palmer, J. L.

    2014-03-01

    Advanced hybrid powerplants combining a fuel cell and battery can enable significantly higher endurance for small, electrically powered unmanned aircraft systems, compared with batteries alone. However, detailed investigations of the static and dynamic performance of such systems are required to address integration challenges. This article describes a series of tests used to characterise the Horizon Energy Systems' AeroStack hybrid, fuel-cell-based powertrain. The results demonstrate that a significant difference can exist between the dynamic performance of the fuel-cell system and its static polarisation curve, confirming the need for detailed measurements. The results also confirm that the AeroStack's lithium-polymer battery plays a crucial role in its response to dynamic load changes and protects the fuel cell from membrane dehydration and fuel starvation. At low static loads, the AeroStack fuel cell recharges the battery with currents up to 1 A, which leads to further differences with the polarisation curve.

  1. NASA Broad Specification Fuels Combustion Technology program - Pratt and Whitney Aircraft Phase I results and status

    NASA Technical Reports Server (NTRS)

    Lohmann, R. P.; Fear, J. S.

    1982-01-01

    In connection with increases in the cost of fuels and the reduced availability of high quality petroleum crude, a modification of fuel specifications has been considered to allow acceptance of poorer quality fuels. To obtain the information upon which a selection of appropriate fuels for aircraft can be based, the Broad Specification Fuels Combustion Technology program was formulated by NASA. A description is presented of program-related investigations conducted by an American aerospace company. The specific objective of Phase I of this program has been to evaluate the impact of the use of broadened properties fuels on combustor design through comprehensive combustor rig testing. Attention is given to combustor concepts, experimental evaluation, results obtained with single stage combustors, the stage combustor concept, and the capability of a variable geometry combustor.

  2. Flame Tube and Ballistic Evaluation of Explosafe Aluminum Foil for Aircraft Fuel Tank Explosion Protection

    DTIC Science & Technology

    1980-04-01

    OIL FOR AIRCRAFT FUEL TANK EXPLOSION Aug• •77-MarI* ;P7 9 .OTECTI. 6 RFORMING ORG REPOT N BER •. j• H•. .J...Bob. Fiur 82 Scemtc iara f laeTue es qupmn Dra’i V3 56 .1 .~~~~~anfl Nock...... 7 2 7 . AFWAL-TR-80- 2031

  3. Aircraft Fuel, Hydraulic and Pneumatic Systems (Course Outlines), Aviation Mechanics 3 (Air Frame): 9067.01.

    ERIC Educational Resources Information Center

    Dade County Public Schools, Miami, FL.

    This document presents an outline for a 135-hour course designed to familiarize the student with the operation, inspection, and repair of aircraft fuel, hydraulic, and pneumatic systems. It is designed to help the trainee master the knowledge and skills necessary to become an aviation airframe mechanic. The aviation airframe maintenance technician…

  4. Emissions of industrial furnaces burning diesel fuel oils of various sulfur contents with NaCl - contained atmospheric air

    SciTech Connect

    Lin, C.Y.; Hsieh, M.J.

    1996-04-01

    A small furnace associated with an industrial automatic burner was employed in this study to investigate the influences of sulfur content of fuel oils burned with NaCl contained atmospheric air on the emission characteristics of marine or industrial power-plants. The sulfur contents of 0.3 wt% and 1.0 wt% were considered. Diesel fuel oil A which approximates ASTM No. 2 fuel oil was atomized by the inlet air added with NaCl of 1.5 ppm concentration and thereafter burned within the furnace. It was found that under this burning condition the CO, SO{sub 2}, and O{sub 2} emissions increased with the addition of sulfur in the fuel oil. However, the gas temperature and NO{sub x} concentration were affected by the increase of sulfur content to only a minor extent. 14 refs., 10 figs.

  5. Quantitative Surface Emissivity and Temperature Measurements of a Burning Solid Fuel Accompanied by Soot Formation

    NASA Technical Reports Server (NTRS)

    Piltch, Nancy D.; Pettegrew, Richard D.; Ferkul, Paul; Sacksteder, K. (Technical Monitor)

    2001-01-01

    Surface radiometry is an established technique for noncontact temperature measurement of solids. We adapt this technique to the study of solid surface combustion where the solid fuel undergoes physical and chemical changes as pyrolysis proceeds, and additionally may produce soot. The physical and chemical changes alter the fuel surface emissivity, and soot contributes to the infrared signature in the same spectral band as the signal of interest. We have developed a measurement that isolates the fuel's surface emissions in the presence of soot, and determine the surface emissivity as a function of temperature. A commercially available infrared camera images the two-dimensional surface of ashless filter paper burning in concurrent flow. The camera is sensitive in the 2 to 5 gm band, but spectrally filtered to reduce the interference from hot gas phase combustion products. Results show a strong functional dependence of emissivity on temperature, attributed to the combined effects of thermal and oxidative processes. Using the measured emissivity, radiance measurements from several burning samples were corrected for the presence of soot and for changes in emissivity, to yield quantitative surface temperature measurements. Ultimately the results will be used to develop a full-field, non-contact temperature measurement that will be used in spacebased combustion investigations.

  6. Coated Particle Fuel and Deep Burn Program Monthly Highlights June 2011

    SciTech Connect

    Snead, Lance Lewis; Bell, Gary L; Besmann, Theodore M

    2011-07-01

    During FY 2011 the CP & DB Program will report Highlights on a monthly basis, but will no longer produce Quarterly Progress Reports. Technical details that were previously included in the quarterly reports will be included in the appropriate Milestone Reports that are submitted to FCRD Program Management. These reports will also be uploaded to the Deep Burn website. The Monthly Highlights report for May 2011, ORNL/TM-2011/126, was distributed to program participants on June 9, 2011. As reported previously, the final Quarterly for FY 2010, Deep Burn Program Quarterly Report for July - September 2010, ORNL/TM-2010/301, was announced to program participants and posted to the website on December 28, 2010. This report discusses the following: (1) Fuel Performance Modeling - Fuel Performance Analysis; (2) Thermochemical Data and Model Development - (a) Thermochemical Behavior, (b) Thermomechanical Modeling, (c) Actinide and Fission Product Transport; (3) TRU (transuranic elements) TRISO (tri-structural isotropic) Development - (a) TRU Kernel Development, (b) Coating Development; and (4) LWR Fully Ceramic Fuel - (a) FCM Fabrication Development, (b) FCM Irradiation Testing.

  7. Organic Mass Fragments and Organic Functional Groups in Aged Biomass Burning and Fossil Fuel Combustion Aerosol

    NASA Astrophysics Data System (ADS)

    Day, D. A.; Hawkins, L. N.; Russell, L. M.

    2009-12-01

    Organic functional group concentrations in submicron aerosol particles collected from 27 June to 17 September at the Scripps Pier in La Jolla, California as part of AeroSCOPE 2008 were quantified using Fourier Transform Infrared (FTIR) spectroscopy. Organic and inorganic non-refractory components in the same air masses were quantified using a Quadrupole Aerosol Mass Spectrometer (Q-AMS). Previous measurements at the Scripps pier indicate that a large fraction of submicron particle mass originates in Los Angeles and the port of Long Beach. Additional particle sources to the region include local urban emissions and periodic biomass burning during large wildfires. Three distinct types of organic aerosol components were identified from organic composition and elemental tracers, including biomass burning, fossil fuel combustion, and polluted marine components. Fossil fuel combustion organic aerosol was dominated by unsaturated alkane and was correlated with sulfur, vanadium, and nickel supporting ship and large trucks in and around the Los Angeles/Long Beach region as the dominant source. Biomass burning organic aerosol comprised a smaller unsaturated alkane fraction and larger fractions of non-acid carbonyl, amine, and carboxylic acid and was correlated with potassium and bromine. Polluted marine organic aerosol was dominated by organic hydroxyl and unsaturated alkane and was not correlated with any elemental tracers. Mass spectra of the organic aerosol support the aerosol sources determined by organic functional groups and elemental tracers and contain fragments commonly attributed to oxygenated organic aerosol (OOA), hydrocarbon-like organic aerosol (HOA), and biomass burning organic aerosol (BBOA). Comparisons of the PMF-derived Q-AMS source spectra with FTIR source spectra and functional group composition provide additional information on the relationship between commonly reported organic aerosol factors and organic functional groups in specific organic aerosol

  8. Aircraft fuel conservation technology. Task force report, September 10, 1975

    NASA Technical Reports Server (NTRS)

    1975-01-01

    An advanced technology program is described for reduced fuel consumption in air transport. Cost benefits and estimates are given for improved engine design and components, turboprop propulsion systems, active control systems, laminar flow control, and composite primary structures.

  9. Commercial Aircraft Airframe Fuel Systems Survey and Analysis.

    DTIC Science & Technology

    1982-07-01

    VALVE M~l’ ® FE(L FE06Cu~i 5u~jt~~ vat~FUEIL I.AL r(E PUE L FUEL f PUt GE VALVI AADTIV FWWV STAUIFBY Boa 7 HILL~E CAV 38 GAL U JILL ZAM StOOP VCA’r...to FAA. 3. Fiorentino, A., De Saro, R., and Franz , T., An Assessment of the Use Of Antimisting Fuel in Turbofan Engines, United Technologies

  10. Aircraft Geared Architecture Reduces Fuel Cost and Noise

    NASA Technical Reports Server (NTRS)

    2015-01-01

    In an effort to increase fuel efficiency and reduce noise in commercial airplanes, NASA aeronautics teamed up with East Hartford, Connecticut-based Pratt & Whitney through a Space Act Agreement to help the company increase the efficiency of its turbofan engine. The company's new PurePower line of engines is 15 percent more fuel-efficient and up to 75 percent quieter than its competitors.

  11. Alternative Fuels Tests on a C-17 Aircraft: Emissions Characteristics

    DTIC Science & Technology

    2010-12-01

    control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1. REPORT DATE (DD-MM-YY) 2. REPORT TYPE 3 . DATES COVERED (From - To) December...Emissions were collected from engine 3 of the parked aircraft operated on conventional JP-8 and 50/50 blends of JP-8 and a beef tallow-derived HRJ, and a... 3 2.1.2 Gaseous Emissions.............................................................................. 5

  12. Air pollution from aircraft. [jet exhaust - aircraft fuels/combustion efficiency

    NASA Technical Reports Server (NTRS)

    Heywood, J. B.; Chigier, N. A.

    1975-01-01

    A model which predicts nitric oxide and carbon monoxide emissions from a swirl can modular combustor is discussed. A detailed analysis of the turbulent fuel-air mixing process in the swirl can module wake region is reviewed. Hot wire anemometry was employed, and gas sampling analysis of fuel combustion emissions were performed.

  13. Method and composition for modifying burning of sulfur in coals and hydrocarbon fuels

    SciTech Connect

    Jordan, F.L.

    1981-06-23

    Efficiency of internal combustion engine performance, I.E. Improved mileage per gallon, and improved performance, E.G. Lower exhaust temperature, is increased by the addition of carotenoids, beta-carotene in particular, to diesel fuel before use, and the combustion of coal is improved, I.E. higher btu/lb results, sulfur in emission from such coal combustion is reduced, and sulfur in ash is increased, by the addition of squalene, squalane , carotenoids, beta-carotene in particular, hemoglobin and chlorophyll to the coal before burning.

  14. A Survey of Studies on Ignition and Burn of Inertially Confined Fuels

    NASA Astrophysics Data System (ADS)

    Atzeni, Stefano

    2016-10-01

    A survey of studies on ignition and burn of inertial fusion fuels is presented. Potentials and issues of different approaches to ignition (central ignition, fast ignition, volume ignition) are addressed by means of simple models and numerical simulations. Both equimolar DT and T-lean mixtures are considered. Crucial issues concerning hot spot formation (implosion symmetry for central ignition; igniting pulse parameters for fast ignition) are briefly discussed. Recent results concerning the scaling of the ignition energy with the implosion velocity and constrained gain curves are also summarized.

  15. Method of burning sulfur-containing fuels in a fluidized bed boiler

    DOEpatents

    Jones, Brian C.

    1982-01-01

    A method of burning a sulfur-containing fuel in a fluidized bed of sulfur oxide sorbent wherein the overall utilization of sulfur oxide sorbent is increased by comminuting the bed drain solids to a smaller average particle size, preferably on the order of 50 microns, and reinjecting the comminuted bed drain solids into the bed. In comminuting the bed drain solids, particles of spent sulfur sorbent contained therein are fractured thereby exposing unreacted sorbent surface. Upon reinjecting the comminuted bed drain solids into the bed, the newly-exposed unreacted sorbent surface is available for sulfur oxide sorption, thereby increasing overall sorbent utilization.

  16. Emissions of nitrogen-containing organic compounds from the burning of herbaceous and arboraceous biomass: Fuel composition dependence and the variability of commonly used nitrile tracers

    NASA Astrophysics Data System (ADS)

    Coggon, Matthew M.; Veres, Patrick R.; Yuan, Bin; Koss, Abigail; Warneke, Carsten; Gilman, Jessica B.; Lerner, Brian M.; Peischl, Jeff; Aikin, Kenneth C.; Stockwell, Chelsea E.; Hatch, Lindsay E.; Ryerson, Thomas B.; Roberts, James M.; Yokelson, Robert J.; Gouw, Joost A.

    2016-09-01

    Volatile organic compounds (VOCs) emitted from residential wood and crop residue burning were measured in Colorado, U.S. When compared to the emissions from crop burning, residential wood burning exhibited markedly lower concentrations of acetonitrile, a commonly used biomass burning tracer. For both herbaceous and arboraceous fuels, the emissions of nitrogen-containing VOCs (NVOCs) strongly depend on the fuel nitrogen content; therefore, low NVOC emissions from residential wood burning result from the combustion of low-nitrogen fuel. Consequently, the emissions of compounds hazardous to human health, such as HNCO and HCN, and the formation of secondary pollutants, such as ozone generated by NOx, are likely to depend on fuel nitrogen. These results also demonstrate that acetonitrile may not be a suitable tracer for domestic burning in urban areas. Wood burning emissions may be best identified through analysis of the emissions profile rather than reliance on a single tracer species.

  17. Siberian and North American Biomass Burning Contributions to the Processes that Influenced the 2008 Arctic Aircraft and Satellite Field Campaigns

    NASA Astrophysics Data System (ADS)

    Soja, A. J.; Stocks, B. J.; Carr, R.; Pierce, R. B.; Natarajan, M.; Fromm, M.

    2009-05-01

    Current climate change scenarios predict increases in biomass burning in terms of increases in fire frequency, area burned, fire season length and fire season severity, particularly in boreal regions. Climate and weather control fire danger, which strongly influences the severity of fire events, and these in turn, feed back to the climate system through direct and indirect emissions, modifying cloud condensation nuclei and altering albedo (affecting the energy balance) through vegetative land cover change and deposition. Additionally, fire emissions adversely influence air quality and human health downwind of burning. The boreal zone is significant because this region stores the largest reservoir of terrestrial carbon, globally, and will experience climate change impacts earliest. Boreal biomass burning is an integral component to several of the primary goals of the ARCTAS (Arctic Research of the Composition of the Troposphere from Aircraft and Satellites) and ARCPAC (Aerosol, Radiation, and Cloud Processes affecting Arctic Climate) 2008 field campaigns, which include its implication for atmospheric composition and climate, aerosol radiative forcing, and chemical processes with a focus on ozone and aerosols. Both the spring and summer phases of ARCTAS and ARCPAC offered substantial opportunities for sampling fresh and aged biomass burning emissions. However, the extent to which spring biomass burning influenced arctic haze was unexpected, which could inform our knowledge of the formation of arctic haze and the early deposition of black carbon on the icy arctic surface. There is already evidence of increased extreme fire seasons that correlate with warming across the circumboreal zone. In this presentation, we discuss seasonal and annual fire activity and anomalies that relate to the ARCTAS and ARCPAC spring (April 1 - 20) and summer (June 18 - July 13) periods across Siberia and North America, with particular emphasis on fire danger and fire behavior as they relate

  18. RF Coupling into the Fuel Tank of a Large Transport Aircraft from Intentionally Transmitting Peds in the Passenger Cabin

    NASA Technical Reports Server (NTRS)

    Nguyen, Truong X.; Dudley, Kenneth L.; Scearce, Stephen A.; Ely, Jay J.; Richardson, Robert E.; Hatfield, Michael O.

    2000-01-01

    An investigation was performed to study the potential for radio frequency (RF) power radiated from Portable Electronic Devices (PEDs) to create an arcing/sparking event within the fuel tank of a large transport aircraft. This paper describes the experimental methods used for measuring RF coupling to the fuel tank and Fuel Quantity Indication System (FQIS) wiring from PED sources located in the passenger cabin. To allow comparison of voltage/current data obtained in a laboratory chamber FQIS installation to an actual aircraft FQIS installation, aircraft fuel tank RF reverberation characteristics were also measured. Results from the measurements, along with a survey of threats from typical intentional transmitting PEDs are presented. The resulting worst-case power coupled onto fuel tank FQIS wiring is derived. The same approach can be applied to measure RF coupling into various other aircraft systems.

  19. Scheduled Civil Aircraft Emission Inventories for 1999: Database Development and Analysis

    NASA Technical Reports Server (NTRS)

    Sutkus, Donald J., Jr.; Baughcum, Steven L.; DuBois, Douglas P.

    2001-01-01

    This report describes the development of a three-dimensional database of aircraft fuel burn and emissions (NO(x), CO, and hydrocarbons) for the scheduled commercial aircraft fleet for each month of 1999. Global totals of emissions and fuel burn for 1999 are compared to global totals from 1992 and 2015 databases. 1999 fuel burn, departure and distance totals for selected airlines are compared to data reported on DOT Form 41 to evaluate the accuracy of the calculations. DOT Form T-100 data were used to determine typical payloads for freighter aircraft and this information was used to model freighter aircraft more accurately by using more realistic payloads. Differences in the calculation methodology used to create the 1999 fuel burn and emissions database from the methodology used in previous work are described and evaluated.

  20. Coated Particle Fuel and Deep Burn Program Monthly Highlights April 2011

    SciTech Connect

    Snead, Lance Lewis; Bell, Gary L; Besmann, Theodore M

    2011-05-01

    The baseline change proposal BCP-FCRD-11026 submitted to change the due date for M21AF080202 'Demonstrate fabrication of Transuranic kernels of Plutonium-239/3.5at%Neptunium-237 using newly installed glove box facilities in ORNL 7930 hot cell complex' from 4/25/11 to 3/30/12 was approved this month. During FY 2011 the CP & DB Program will report Highlights on a monthly basis, but will no longer produce Quarterly Progress Reports. Technical details that were previously included in the quarterly reports will be included in the appropriate Milestone Reports that are submitted to FCRD Program Management. These reports will also be uploaded to the Deep Burn website. The Monthly Highlights report for March 2011, ORNL/TM-2011/96, was distributed to program participants on April 8, 2011. As reported previously, the final Quarterly for FY 2010, Deep Burn Program Quarterly Report for July - September 2010, ORNL/TM-2010/301, was announced to program participants and posted to the website on December 28, 2010. This report discusses the following: (1) Thermochemical Data and Model Development - (a) Thermochemical Modeling, (b) Thermomechanical Behavior, (c) Actinide and Fission Product Transport, (d) Radiation Damage and Properties; (2) TRU (transuranic elements) TRISO (tri-structural isotropic) Development - (a) TRU Kernel Development, (b) Coating Development; (3) Advanced TRISO Applications - Metal Matrix Fuels for LWR; (4) LWR Fully Ceramic Fuel - (a) FCM Fabrication Development, (b) FCM Irradiation Testing; (5) Fuel Performance and Analytical Analysis - Fuel Performance Modeling; and (6) ZrC Properties and Handbook - Properties of ZrC.

  1. Closed fuel cycle with increased fuel burn-up and economy applying of thorium resources

    NASA Astrophysics Data System (ADS)

    Kulikov, G. G.; Apse, V. A.

    2017-01-01

    The possible role of existing thorium reserves in the Russian Federation on engaging thorium in being currently closed (U-Pu)-fuel cycle of nuclear power of the country is considered. The application efficiency of thermonuclear neutron sources with thorium blanket for the economical use of existing thorium reserves is demonstrated. The aim of the work is to find solutions of such major tasks as the reduction of both front-end and back-end of nuclear fuel cycle and an enhancing its protection against the uncontrolled proliferation of fissile materials by means of the smallest changes in the fuel cycle. During implementation of the work we analyzed the results obtained earlier by the authors, brought new information on the number of thorium available in the Russian Federation and made further assessments. On the basis of proposal on the inclusion of hybrid reactors with Th-blanket into the future nuclear power for the production of light uranium fraction 232+233+234U, and 231Pa, we obtained the following results: 1. The fuel cycle will shift from fissile 235U to 233U which is more attractive for thermal power reactors. 2. The light uranium fraction is the most "protected" in the uranium component of fuel and mixed with regenerated uranium will in addition become a low enriched uranium fuel, that will weaken the problem of uncontrolled proliferation of fissile materials. 3. 231Pa doping into the fuel stabilizes its multiplying properties that will allow us to implement long-term fuel residence time and eventually to increase the export potential of all nuclear power technologies. 4. The thorium reserves being near city Krasnoufimsk (Russia) are large enough for operation of large-scale nuclear power of the Russian Federation of 70 GWe capacity during more than a quarter century under assumption that thorium is loaded into blankets of hybrid TNS only. The general conclusion: the inclusion of a small number of hybrid reactors with Th-blanket into the future nuclear

  2. The problem of liquid fuels (for aircraft engines)

    NASA Technical Reports Server (NTRS)

    Gallo, Gino

    1924-01-01

    The crisis which troubles the world market for liquid fuel in general and for carburants in particular is doubtless one of the most serious ever experienced by modern industry. It is a national crisis of economic and political independence for countries like Italy and France. The solutions suggested for meeting the lack of liquid fuel may be summed up under two general headings: the economical use of the petroleum now available; creation of petroleum substitutes from natural sources within the country. The process of cracking is described at length.

  3. Experimental investigation on the morphology of soot aggregates from the burning of typical solid and liquid fuels

    NASA Astrophysics Data System (ADS)

    Huang, Dongmei; Guo, Chenning; Shi, Long

    2017-03-01

    Soot particles from the burning of typical fuels are one of the critical sources causing environmental problems and human disease. To understand the soot formation of these typical fuels, the size and morphology of soot aggregates produced from the burning of typical solid and liquid fuels, including diesel, kerosene, natural rubber (NR) latex foam, and wood crib, were studied by both extractive sampling and subsequent image analysis. The 2D and 3D fractal dimensions together with the diameter distribution of agglomerate and primary particles were analyzed for these four typical fuels. The average diameters of the primary particles were within 45-85 nm when sampling from different heights above the fire sources. Irregular sheet structures and flake-like masses were observed from the burning of NR latex foam and wood cribs. Superaggregates with a mean maximum length scale of over 100 μm were also found from the burning of all these four tested fuels. The fractal dimension of a single aggregate was 3 for all the tested fuels.

  4. Characterization of Pollution Outflow From India and Arabia: Biomass Burning and Fossil Fuel Combustion

    NASA Astrophysics Data System (ADS)

    Wisthaler, A.; Hansel, A.; Stehr, J. W.; Dickerson, R. R.; Guazzotti, S. A.; Coffee, K.; Prather, K. A.

    One objective of the Indian Ocean Experiment (INDOEX 1999) was to character- ize the chemical composition of pollution outflow from South Asia. Real-time single particle analysis (ATOFMS, Univ. of California-Riverside), CO analysis (Nondisper- sive Infrared Gas Filter Correlation Photometer, Univ. of Maryland) and fast-response VOC measurements (PTR-MS, Univ. of Innsbruck) measurements were performed onboard the NOAA R/V Ronald H. Brown. Gas phase and aerosol chemical compo- sition of encountered air parcels changed according to their geographic origin traced by backtrajectory analysis (continental air from Arabia and India; maritime air). The relative strength of combustion related pollution sources (biomass burning (BB) vs. fossil fuel (FF) combustion) was determined from the relative abundance of differ- ent tracers: acetonitrile (BB), CO (BB and FF), submicron particles containing car- bon but no potassium (FF), submicron particles containing carbon and potassium (BB and coal combustion), submicron particles containing carbon, potassium and lithium (coal combustion). Arabian air clearly reflected the signature of fossil fuel combustion, while air from the Indian subcontinent was strongly influenced by biomass burning.

  5. The domestication of fire: the relationship between biomass fuel, fossil fuel and burns.

    PubMed

    Albertyn, R; Rode, H; Millar, A J W; Peck, M D

    2012-09-01

    Primitive man's discovery and use of fire had a tremendous impact on modern development. It changed lifestyles, and brought with it new fuel sources and cooking methods. It also introduced devastation, injury, pain, disfigurement, and loss of life, and the need to continuously develop management, training and prevention programs.

  6. Safety demonstration tests of hypothetical explosive burning in the cell and air ventilation system in a nuclear fuel reprocessing plant

    SciTech Connect

    Nisio, G.; Suzuki, M.; Mukaide, S. )

    1991-09-01

    This paper reports on a nuclear fuel reprocessing plant equipped with an air ventilation system consisting of cells, ducts, dampers, high-efficiency particulate air filters, and blowers. This ventilation system is required to have multiple safeguards in order to confine airborne radioactive materials within the plant in the event of fire, explosion, and criticality. To evaluate these safeguards, three kinds of explosive burning tests are performed using a large-scale facility simulating the ventilation system of a reprocessing plant. In the boilover test, an organic solvent is burned on a layer of water in a burning pan to determine the magnitude of the burning caused by the sudden boiling of the water under the solvent. The optimum conditions for boilover burning are determined by the relationship between the pan size and the ventilation rate.

  7. Engine Performance and Knock Rating of Fuels for High-output Aircraft Engines

    NASA Technical Reports Server (NTRS)

    Rothbrock, A M; Biermann, Arnold E

    1938-01-01

    Data are presented to show the effects of inlet-air pressure, inlet-air temperature, and compression ratio on the maximum permissible performance obtained on a single-cylinder test engine with aircraft-engine fuels varying from a fuel of 87 octane number to one 100 octane number plus 1 ml of tetraethyl lead per gallon. The data were obtained on a 5-inch by 5.75-inch liquid-cooled engine operating at 2,500 r.p.m. The compression ratio was varied from 6.50 to 8.75. The inlet-air temperature was varied from 120 to 280 F. and the inlet-air pressure from 30 inches of mercury absolute to the highest permissible. The limiting factors for the increase in compression ratio and in inlet-air pressure was the occurrence of either audible or incipient knock. The data are correlated to show that, for any one fuel,there is a definite relationship between the limiting conditions of inlet-air temperature and density at any compression ratio. This relationship is dependent on the combustion-gas temperature and density relationship that causes knock. The report presents a suggested method of rating aircraft-engine fuels based on this relationship. It is concluded that aircraft-engine fuels cannot be satisfactorily rated by any single factor, such as octane number, highest useful compression ratio, or allowable boost pressure. The fuels should be rated by a curve that expresses the limitations of the fuel over a variety of engine conditions.

  8. Fuel conservative guidance concept for shipboard landing of powered-life aircraft

    NASA Technical Reports Server (NTRS)

    Warner, D. N., Jr.; Mcghee, L. A.; Mclean, J. D.; Schmidt, G. K.

    1984-01-01

    A simulation study was undertaken to investigate the application of energy conservative guidance (ECG) software, developed at NASA Ames Research Center, to improve the time and fuel efficiency of powered lift airplanes operating from aircraft carriers at sea. When a flightpath is indicated by a set of initial conditions for the aircraft and a set of positional waypoints with associated airspeeds, the ECG software synthesizes the necessary guidance commands to optimize fuel and time along the specified path. A major feature of the ECG system is the ability to synthesize a trajectory that will allow the aircraft to capture the specified path at any waypoint with the desired heading and airspeed from an arbitrary set of initial conditions. Five paths were identified and studied. These paths demonstrate the ECG system's ability to save flight time and fuel by more efficiently managing the aircraft's capabilities. Results of this simulation study show that when restrictions on the approach flightpath imposed for manual operation are removed completely, fuel consumption during the approach was reduced by as much as 49% (610 lb fuel) and the time required to fly the flightpath was reduced by as much as 41% (5 min). Savings due to ECG were produced by: (1) shortening the total flight time; (2) keeping the airspeed high as long as possible to minimize time spent flying in a regime in which more engine thrust is required for lift to aid the aerodynamic lift; (3) minimizing time spent flying at constant altitude at slow airspeeds; and (4) synthesizing a path from any location for a direct approach to landing without entering a holding pattern or other fixed approach path.

  9. Aerosols upwind of Mexico City during the MILAGRO campaign: regional scale biomass burning, dust and volcanic ash from aircraft measurements

    NASA Astrophysics Data System (ADS)

    Junkermann, W.; Steinbrecher, R.

    2009-04-01

    During the MILAGRO Campaign March/April 2006 a series of aircraft flights with the FZK microlight D-MIFU were performed in the area southeast of Mexico City starting from Puebla airport, circling the national park area of Ixtachiuatl and Popocatepetl and scanning the Chalco valley down to Cuautla in the Cuernavaca province. All flights were combined with vertical profiles up to 4500 m a.s.l. in several locations, typically north of volcano Ixtachiuatl on the Puebla side, above Chalco or Tenago del Aire and south of volcano Popocatepetl, either at Cuautla or Atlixco. In Tenango del Aire a ceilometer was additionally operated continuously for characterization of the planetary boundary layer. The aircraft carried a set of aerosol instrumentation, fine and coarse particles and size distributions as well as a 7 wavelength aethalometer. Additionally meteorological parameters, temperature and dewpoint, global radiation and actinic radiation balance, respectively photolysis rates, and ozone concentrations were measured. The instrumentation allowed to characterize the aerosol according to their sources and also their impact on radiation transfer. Biomass burning aerosol, windblown dust and volcanic ash were identified within the upwind area of Mexico City with large differences between the dry season in the first weeks of the campaign and the by far cleaner situation after beginning thunderstorm activity towards the end of the campaign. Also the aerosol characteristics inside and outside the Mexico City basin were often completely different. With wind speeds of ~ 5 m/sec from southerly directions in the Chalco valley the aerosol mixture can reach the City within ~ 2 h. Rural aerosol mixtures from the Cuernavaca plain were mixed during the transport with dust from the MC basin. Very high intensity biomass burning plumes normally reached higher altitudes and produced pyrocumulus clouds. These aerosols were injected mainly into the free troposphere. Within the MC basin a large

  10. Studies of new perfluoroether elastomeric sealants. [for aircraft fuel tanks

    NASA Technical Reports Server (NTRS)

    Basiulis, D. I.; Salisbury, D. P.

    1981-01-01

    Channel and filleting sealants were developed successfully from cyano and diamidoxime terminated perfluoro alkylene ether prepolymers. The prepolymers were polymerized, formulated and tested. The polymers and/or formulations therefrom were evaluated as to their physical, mechanical and chemical properties (i.e., specific gravity, hardness, nonvolatile content, corrosion resistance, stress corrosion, pressure rupture resistance, low temperature flexibility, gap sealing efficiency, tensile strength and elongation, dynamic mechanical behavior, compression set, fuel resistance, thermal properties and processability). Other applications of the formulated polymrs and incorporation of the basic prepolymers into other polymeric systems were investigated. A cyano terminated perfluoro alkylene oxide triazine was formulated and partially evaluated. The channel sealant in its present formulation has excellent pressure rupture resistance and surpasses present MIL specifications before and after fuel and heat aging.

  11. Chemical composition of air masses transported from Asia to the U.S. West Coast during ITCT 2K2: Fossil fuel combustion versus biomass-burning signatures

    NASA Astrophysics Data System (ADS)

    de Gouw, J. A.; Cooper, O. R.; Warneke, C.; Hudson, P. K.; Fehsenfeld, F. C.; Holloway, J. S.; Hübler, G.; Nicks, D. K., Jr.; Nowak, J. B.; Parrish, D. D.; Ryerson, T. B.; Atlas, E. L.; Donnelly, S. G.; Schauffler, S. M.; Stroud, V.; Johnson, K.; Carmichael, G. R.; Streets, D. G.

    2004-12-01

    As part of the Intercontinental Transport and Chemical Transformation experiment in 2002 (ITCT 2K2), a National Oceanic and Atmospheric Administration (NOAA) WP-3D research aircraft was used to study the long-range transport of Asian air masses toward the west coast of North America. During research flights on 5 and 17 May, strong enhancements of carbon monoxide (CO) and other species were observed in air masses that had been transported from Asia. The hydrocarbon composition of the air masses indicated that the highest CO levels were related to fossil fuel use. During the flights on 5 and 17 May and other days, the levels of several biomass-burning indicators increased with altitude. This was true for acetonitrile (CH3CN), methyl chloride (CH3Cl), the ratio of acetylene (C2H2) to propane (C3H8), and, on May 5, the percentage of particles measured by the particle analysis by laser mass spectrometry (PALMS) instrument that were attributed to biomass burning based on their carbon and potassium content. An ensemble of back-trajectories, calculated from the U.S. west coast over a range of latitudes and altitudes for the entire ITCT 2K2 period, showed that air masses from Southeast Asia and China were generally observed at higher altitudes than air from Japan and Korea. Emission inventories estimate the contribution of biomass burning to the total emissions to be low for Japan and Korea, higher for China, and the highest for Southeast Asia. Combined with the origin of the air masses versus altitude, this qualitatively explains the increase with altitude, averaged over the whole ITCT 2K2 period, of the different biomass-burning indicators.

  12. Biomass Burning versus Fossil Fuel Combustion Signatures of Air Masses Transported from Asia to the U.S. West Coast during ITCT2k2

    NASA Astrophysics Data System (ADS)

    de Gouw, J.; Cooper, O.; Warneke, C.; Hudson, P.; Brock, C.; Fehsenfeld, F.; Holloway, J.; Huebler, G.; Murphy, D.; Nowak, J.; Parrish, D.; Ryerson, T.; Trainer, M.; Atlas, E.

    2003-12-01

    The goal of the Intercontinental Transport and Chemical Transformation experiment in 2002 (ITCT2k2) was to study the transport of air pollution from Asia across the Pacific Ocean, and the implications for the background atmospheric composition at the surface in North America. During research flights of the NOAA WP-3 research aircraft on May 5 and 17, strong enhancements of carbon monoxide (CO) and other species were observed in air masses that had been transported from Asia in the free troposphere to North America. The hydrocarbon composition of the air masses indicated that the highest CO levels were related to fossil fuel use. During the flights on May 5, 17 and other days, the levels of several biomass-burning indicators increased with altitude. This was true for acetonitrile (CH3CN), methyl chloride (CH3Cl), the ratio of acetylene (C2H2) versus propane (C3H8), and the percentage of particles measured by the PALMS (particle analysis by laser mass spectrometry) instrument that were attributed to biomass burning based on their carbon and potassium content. An ensemble of back-trajectories, calculated from the U.S. west coast at various latitudes and pressures during the entire ITCT2k2 period, showed that air masses from South-East Asia and China were generally transported at higher altitudes than air from Japan and Korea. Emission inventories estimate the contribution of biomass burning to the total emissions to be low for Japan and Korea, higher for China, and the highest for South-East Asia. Combined with the origin of the air masses versus altitude determined by the back-trajectories, this explains the measured altitude profiles of the biomass burning indicators.

  13. Vehicle Design Evaluation Program (VDEP). A computer program for weight sizing, economic, performance and mission analysis of fuel-conservative aircraft, multibodied aircraft and large cargo aircraft using both JP and alternative fuels

    NASA Technical Reports Server (NTRS)

    Oman, B. H.

    1977-01-01

    The NASA Langley Research Center vehicle design evaluation program (VDEP-2) was expanded by (1) incorporating into the program a capability to conduct preliminary design studies on subsonic commercial transport type aircraft using both JP and such alternate fuels as hydrogen and methane;(2) incorporating an aircraft detailed mission and performance analysis capability; and (3) developing and incorporating an external loads analysis capability. The resulting computer program (VDEP-3) provides a preliminary design tool that enables the user to perform integrated sizing, structural analysis, and cost studies on subsonic commercial transport aircraft. Both versions of the VDEP-3 Program which are designated preliminary Analysis VDEP-3 and detailed Analysis VDEP utilize the same vehicle sizing subprogram which includes a detailed mission analysis capability, as well as a geometry and weight analysis for multibodied configurations.

  14. A Preliminary Study of Fuel Injection and Compression Ignition as Applied to an Aircraft Engine Cylinder

    NASA Technical Reports Server (NTRS)

    Gardiner, Arthur W

    1927-01-01

    This report summarizes some results obtained with a single cylinder test engine at the Langley Field Laboratory during a preliminary investigation of the problem of applying fuel injection and compression ignition to aircraft engines. For this work a standard Liberty Engine cylinder was fitted with a high compression, 11.4 : 1 compression ratio, piston, and equipped with an airless injection system, including a primary fuel pump, an injection pump, and an automatic injection valve. The results obtained during this investigation have indicated the possibility of applying airless injection and compression ignition to a cylinder of this size, 8-inch bore by 7-inch stroke, when operating at engine speeds as high as 1,850 R. P. M. A minimum specific fuel consumption with diesel engine fuel oil of 0.30 pound per I. HP. Hour was obtained when developing about 16 B. HP. At 1,730 R. P. M.

  15. Aircraft emissions, plume chemistry, and alternative fuels: results from the APEX, AAFEX, and MDW-2009 campaigns

    NASA Astrophysics Data System (ADS)

    Wood, E. C.; Herndon, S. C.; Timko, M.; Yu, Z.; Miake-Lye, R. C.; Lee, B. H.; Santoni, G.; Munger, J. W.; Wofsy, S.; Anderson, B.; Knighton, W. B.

    2009-12-01

    We describe observations of aircraft emissions from the APEX, JETS-APEX2, APEX3, MDW-2009 and AAFEX campaigns. Direct emissions of HOx precursors are important for understanding exhaust plume chemistry due to their role in determining HOx concentrations. Nitrous acid (HONO) and formaldehyde are crucial HOx precursors and thus drivers of plume chemistry. At idle power, aircraft engine exhaust is unique among fossil fuel combustion sources due to the speciation of both NOx and VOCs. The impacts of emissions of HOx precursors on plume chemistry at low power are demonstrated with empirical observations of rapid NO to NO2 conversion, indicative of rapid HOx chemistry. The impacts of alternative fuels (derived from biomass, coal, and natural gas) on emissions of NOx, CO, and speciated VOCs are discussed.

  16. Environmental Degradation of Fuels, Fluids and Related Materials for Aircraft

    DTIC Science & Technology

    1976-03-01

    yields are quite low, in the range of 10-3. The fluorescence of many aromatic vapors is not quenched by nitrogen, carbon dioxide, or air. The...only very low levels of hydro- carbons . The small C-H stretch band which was observed was probably due to traces of fuel or to a contaminant extracted...observations point to the conclusion that the residue was carbon , likely soot. c. Deposit on Metal Fracture Surface A black deposit which was contained on the

  17. Black Carbon from Biomass Burning Emissions: New Mexico Wildfires and Controlled Laboratory Burns of Fuels Found in the Southwestern US

    NASA Astrophysics Data System (ADS)

    Aiken, A. C.; Dubey, M.; Liu, S.; McMeeking, G. R.; Gorkowski, K.; Arata, C.; Mazzoleni, C.; China, S.; Kreidenweis, S. M.; DeMott, P. J.; Yokelson, R. J.; Robinson, A. L.

    2013-12-01

    Black carbon (BC) is currently considered the second most important global warming factor behind CO2 and is thought to be underestimated by a factor of two in most global models (Bond et al., 2013). Approximately half of BC comes from biomass burning (BB) sources, which are estimated to contribute up to ~0.6 W/m2 warming of the atmosphere. Organic carbon (OC) from fires condenses on and/or mixes with the BC, lowering the overall forcing from BB to 0.03 × 0.12 Wm-2. This reduction depends strongly on the composition and mixing state of OC and BC, which is dependent on fire conditions, e.g. modified combustion efficiency. Models and laboratory measurements indicate that a BC core coated with a non-absorbing layer can enhance absorption by 2, although it has yet to be observed in ambient data to this degree (Cappa et al., 2012). Direct on-line measurements of BC are made with the single particle soot photometer (SP2) from "fresh" and "aged" BB. We investigate BC in concentrated BB plumes from the two largest wildfires in New Mexico's history with different ages and compare them to BC from indoor generation from single-source fuels, e.g. ponderosa pine, juniper, sawgrass, sampled during Fire Lab At Missoula Experiments IV (FLAME-IV). FLAME-IV includes direct emissions, well-mixed samples, and aging studies. Aerosol optical properties were measured using photoacoustic spectrometry for absorption and nephelometry for scattering with the 3-wavelength and single-wavelength Photoacoustic Soot Spectrometers (PASS-3: 405 nm, 532 nm, 781 nm; PASS: 375 nm) and for the first time are compared with the new Photoacoustic Extinctiometer (PAX; 870 nm) during FLAME-IV. Las Conchas Fire (July-August, 2011) BC was sampled after only a few hours of aging and exhibits mostly core-shell structure. Whitewater Baldy Fire (May-June, 2012) BC was sampled after an aging period of 10-20 hours and includes partially coated BC in addition to thickly coated core-shell BC. Partially coated BC is

  18. Effects of Fuel Aromatic Content on Nonvolatile Particulate Emissions of an In-Production Aircraft Gas Turbine.

    PubMed

    Brem, Benjamin T; Durdina, Lukas; Siegerist, Frithjof; Beyerle, Peter; Bruderer, Kevin; Rindlisbacher, Theo; Rocci-Denis, Sara; Andac, M Gurhan; Zelina, Joseph; Penanhoat, Olivier; Wang, Jing

    2015-11-17

    Aircraft engines emit particulate matter (PM) that affects the air quality in the vicinity of airports and contributes to climate change. Nonvolatile PM (nvPM) emissions from aircraft turbine engines depend on fuel aromatic content, which varies globally by several percent. It is uncertain how this variability will affect future nvPM emission regulations and emission inventories. Here, we present black carbon (BC) mass and nvPM number emission indices (EIs) as a function of fuel aromatic content and thrust for an in-production aircraft gas turbine engine. The aromatics content was varied from 17.8% (v/v) in the neat fuel (Jet A-1) to up to 23.6% (v/v) by injecting two aromatic solvents into the engine fuel supply line. Fuel normalized BC mass and nvPM number EIs increased by up to 60% with increasing fuel aromatics content and decreasing engine thrust. The EIs also increased when fuel naphthalenes were changed from 0.78% (v/v) to 1.18% (v/v) while keeping the total aromatics constant. The EIs correlated best with fuel hydrogen mass content, leading to a simple model that could be used for correcting fuel effects in emission inventories and in future aircraft engine nvPM emission standards.

  19. OXIDATION OF MERCURY ACROSS SCR CATALYSTS IN COAL-FIRED POWER PLANTS BURNING LOW RANK FUELS

    SciTech Connect

    Constance Senior

    2004-10-29

    This is the seventh Quarterly Technical Report for DOE Cooperative Agreement No: DE-FC26-03NT41728. The objective of this program is to measure the oxidation of mercury in flue gas across SCR catalyst in a coal-fired power plant burning low rank fuels using a slipstream reactor containing multiple commercial catalysts in parallel. The Electric Power Research Institute (EPRI) and Argillon GmbH are providing co-funding for this program. This program contains multiple tasks and good progress is being made on all fronts. During this quarter, a model of Hg oxidation across SCRs was formulated based on full-scale data. The model took into account the effects of temperature, space velocity, catalyst type and HCl concentration in the flue gas.

  20. Aircraft engine pollution reduction

    NASA Technical Reports Server (NTRS)

    Rudey, R. A.

    1972-01-01

    The effect of engine operation on the types and levels of the major aircraft engine pollutants is described and the major factors governing the formation of these pollutants during the burning of hydrocarbon fuel are discussed. Methods which are being explored to reduce these pollutants are discussed and their application to several experimental research programs are pointed out. Results showing significant reductions in the levels of carbon monoxide, unburned hydrocarbons, and oxides of nitrogen obtained from experimental combustion research programs are presented and discussed to point out potential application to aircraft engines.

  1. Analytical and experimental evaluations of the effect of broad property fuels on combustors for commercial aircraft gas turbine engines

    NASA Technical Reports Server (NTRS)

    Smith, A. L.

    1980-01-01

    The impacts of broad property fuels on the design, performance, durability, emissions, and operational characteristics of current and advanced combustors for commercial aircraft gas turbine engines were studied. The effect of fuel thermal stability on engine and airframe fuel system was evaluated. Tradeoffs between fuel properties, exhaust emissions, and combustor life were also investigated. Results indicate major impacts of broad property fuels on allowable metal temperatures in fuel manifolds and injector support, combustor cyclic durability, and somewhat lesser impacts on starting characteristics, lightoff, emissions, and smoke.

  2. Analysis of fuel-conservative curved decelerating approach trajectories for powered-lift and CTOL jet aircraft

    NASA Technical Reports Server (NTRS)

    Neuman, F.

    1980-01-01

    A method for determining fuel conservative terminal approaches that include changes in altitude, speed, and heading are described. Three different guidance system concepts for STOL aircraft were evaluated in flight: (1) a fixed trajectory system; (2) a system that included a fixed path and a real time synthesized capture flight path; and (3) a trajectory synthesizing system. Simulation results for the augmentor wing jet STOL research aircraft and for the Boeing 727 aircraft are discussed. The results indicate that for minimum fuel consumption, two guidance deceleration segments are required.

  3. Lean-burn hydrogen spark-ignited engines: the mechanical equivalent to the fuel cell

    SciTech Connect

    Aceves, S.M.; Smith, J.R.

    1996-10-01

    Fuel cells are considered as the ideal power source for future vehicles, due to their high efficiency and low emissions. However, extensive use of fuel cells in light-duty vehicles is likely to be years away, due to their high manufacturing cost. Hydrogen-fueled, spark-ignited, homogeneous-charge engines offer a near-term alternative to fuel cells. Hydrogen in a spark-ignited engine can be burned at very low equivalence ratios, so that NO[sub x] emissions can be reduced to less than 10 ppm without catalyst. HC and CO emissions may result from oxidation of engine oil, but by proper design are negligible (a few ppm). Lean operation also results in increased indicated efficiency due to the thermodynamic properties of the gaseous mixture contained in the cylinder. The high effective octane number of hydrogen allows the use of a high compression ratio, further increasing engine efficiency. In this paper, a simplified engine model is used for predicting hydrogen engine efficiency and emissions. The model uses basic thermodynamic equations for the compression and expansion processes, along with an empirical correlation for heat transfer, to predict engine indicated efficiency. A friction correlation and a supercharger/turbocharger model are then used to calculate brake thermal efficiency. The model is validated with many 1345 experimental points obtained in a recent evaluation of a hydrogen research engine. The experimental data are used to adjust the empirical constants in the heat release rate and heat transfer correlation. The adjusted engine model predicts pressure traces, indicated efficiency and NO,, emissions with good accuracy over the range of speed, equivalence ratio and manifold pressure experimentally covered.

  4. Practical solutions to the aircraft minimum fuel, fixed-range, fixed time-of-arrival trajectory optimization problem

    NASA Technical Reports Server (NTRS)

    Sorensen, J. A.; Waters, M. H.

    1980-01-01

    A practical scheme is presented for generating fixed range, minimum fuel vertical flight profiles that also satisfy time-of-arrival constraints. The resulting algorithm is suitable for incorporation into an on-board flight management system. Example results show that such a capability can save up to 6% of fuel burned in flights subject to delays because of terminal area congestion.

  5. Hydrogen Fuel System Design Trades for High-Altitude Long-Endurance Remotely- Operated Aircraft

    NASA Technical Reports Server (NTRS)

    Millis, Marc G.; Tornabene, Robert T.; Jurns, John M.; Guynn, Mark D.; Tomsik, Thomas M.; VanOverbeke, Thomas J.

    2009-01-01

    Preliminary design trades are presented for liquid hydrogen fuel systems for remotely-operated, high-altitude aircraft that accommodate three different propulsion options: internal combustion engines, and electric motors powered by either polymer electrolyte membrane fuel cells or solid oxide fuel cells. Mission goal is sustained cruise at 60,000 ft altitude, with duration-aloft a key parameter. The subject aircraft specifies an engine power of 143 to 148 hp, gross liftoff weight of 9270 to 9450 lb, payload of 440 lb, and a hydrogen fuel capacity of 2650 to 2755 lb stored in two spherical tanks (8.5 ft inside diameter), each with a dry mass goal of 316 lb. Hydrogen schematics for all three propulsion options are provided. Each employs vacuum-jacketed tanks with multilayer insulation, augmented with a helium pressurant system, and using electric motor driven hydrogen pumps. The most significant schematic differences involve the heat exchangers and hydrogen reclamation equipment. Heat balances indicate that mission durations of 10 to 16 days appear achievable. The dry mass for the hydrogen system is estimated to be 1900 lb, including 645 lb for each tank. This tank mass is roughly twice that of the advanced tanks assumed in the initial conceptual vehicle. Control strategies are not addressed, nor are procedures for filling and draining the tanks.

  6. Aircraft Wing Fuel Tank Environmental Simulator Tests for Evaluation of Antimisting Fuels.

    DTIC Science & Technology

    1984-10-01

    Filters 75 5.3 Heat Transfer Considerations 76 5.4 Gel and String Formation 76 5.5 Flowability of ANK 76 6. CONCLUSIONS 76 7. REFERENCES 78 8...Jet A), giving the fuel the property of resisting mist formation. Fuel in this "antimisting" state is susceptible to problems with flowability ...the flowability of AMK to that of normal jet fuel, and to restore its combustion capability, mechanical shearing or other means of destroying the anti

  7. Instant release of fission products in leaching experiments with high burn-up nuclear fuels in the framework of the Euratom project FIRST- Nuclides

    NASA Astrophysics Data System (ADS)

    Lemmens, K.; González-Robles, E.; Kienzler, B.; Curti, E.; Serrano-Purroy, D.; Sureda, R.; Martínez-Torrents, A.; Roth, O.; Slonszki, E.; Mennecart, T.; Günther-Leopold, I.; Hózer, Z.

    2017-02-01

    The instant release of fission products from high burn-up UO2 fuels and one MOX fuel was investigated by means of leach tests. The samples covered PWR and BWR fuels at average rod burn-up in the range of 45-63 GWd/tHM and included clad fuel segments, fuel segments with opened cladding, fuel fragments and fuel powder. The tests were performed with sodium chloride - bicarbonate solutions under oxidizing conditions and, for one test, in reducing Ar/H2 atmosphere. The iodine and cesium release could be partially explained by the differences in sample preparation, leading to different sizes and properties of the exposed surface areas. Iodine and cesium releases tend to correlate with FGR and linear power rating, but the scatter of the data is significant. Although the gap between the fuel and the cladding was closed in some high burn-up samples, fissures still provide possible preferential transport pathways.

  8. Aircraft Observations into the Characteristics of Biomass Burning Instigated 'Regional Haze' Over the Amazon during the SAMBBA Campaign

    NASA Astrophysics Data System (ADS)

    Darbyshire, Eoghan

    2013-04-01

    E. J. N. Darbyshire, J. D. Allan, M. Flynn, W. T. Morgan, A. Hodgson, B. T. Johnson, J. M. Haywood, K. Longo, P. Artaxo and H. Coe Aerosols associated with large scale Biomass Burning (BB) impact upon weather and climate at global and regional scales. However, quantitative evaluation of these effects is impeded by i) a limited understanding of BB processes and ii) a lack of quantitative knowledge of precise BB aerosol physiochemical characteristics, thus resulting in large model uncertainties. One region where these uncertainties are especially manifest is the Amazon Basin (AzB). Intense and widespread burning results in high atmospheric loadings of BB aerosol, which over the course of the dry season develops into a so-called 'regional haze'. This cloaks the AzB in a complex and inhomogeneous mix of BB emissions, characterized by large Aerosol Optical Depths (>1), low visibility and poor air quality. This haze has a substantial impact on the radiation budget over the AzB through direct scattering/absorption and indirect cloud microphysics effects. In order to best constrain the model uncertainties, and given the scale of the AzB earth-atmosphere system, an intensive observation campaign by multiple international institutions was instigated in the South American Biomass Burning Analyses (SAMBBA) project. The findings reported here are from the SAMBBA aircraft campaign, conducted during the 2012 dry season using the large UK research aircraft (FAAM BAe-146). The dense (high AOD), persistent haze expected throughout the campaign was only present for the first five or so days, due to removal via washout/transportation associated with large storms. For the remaining period, a haze was present but much reduced in area and intensity (mostly AOD's <0.6) and far more localized and spatially heterogeneous. Across the three weeks, multiple burns with differing characteristics, origins and processes were sampled, giving rise to haze from various sources, such as rainforest in

  9. Origin of carbonaceous aerosols over the tropical Indian Ocean: Biomass burning or fossil fuels?

    SciTech Connect

    Novakov, T.; Andreae, M.O.; Gabriel, R.; Kirchstetter, T.; Mayol-Bracero, O.L.; Ramanathan, V.

    2000-08-26

    We present an analysis of the carbon, potassium and sulfate content of the extensive aerosol haze layer observed over the tropical Indian Ocean during the Indian Ocean Experiment (INDOEX). The black carbon (BC) content of the haze is as high as 17% of the total fine particle mass (the sum of carbonaceous and soluble ionic aerosol components) which results in significant solar absorption. The ratio of black carbon to organic carbon (OC) (over the Arabian Sea and equatorial Indian Ocean) was a factor of 5 to 10 times larger than expected for biomass burning. This ratio was closer to values measured downwind of industrialized regions in Japan and Western Europe. These results indicate that fossil fuel combustion is the major source of carbonaceous aerosols, including black carbon during the events considered. If the data set analyzed here is representative of the entire INDOEX study then fossil fuel emissions from South Asia must have similarly contributed to aerosols over the whole study region. The INDOEX ratios are substantially different from those reported f or some source regions of South Asia, thus raising the possibility that changes in composition of carbonaceous aerosol may occur during transport.

  10. Impact of future fuel properties on aircraft engines and fuel systems

    NASA Technical Reports Server (NTRS)

    Rudey, R. A.; Grobman, J. S.

    1978-01-01

    This paper describes and discusses the propulsion-system problems that will most likely be encountered if the specifications of hydrocarbon-based jet fuels must undergo significant changes in the future and, correspondingly, the advances in technology that will be required to minimize the adverse impact of these problems. Several investigations conducted are summarized. Illustrations are used to describe the relative effects of selected fuel properties on the behavior of propulsion-system components and fuel systems. The selected fuel properties are those that are most likely to be relaxed in future fuel specifications. Illustrations are also used to describe technological advances that may be needed in the future. Finally, the technological areas needing the most attention are described, and programs that are under way to address these needs are briefly discussed.

  11. A comparison of low-pressure and supercharged operation of polymer electrolyte membrane fuel cell systems for aircraft applications

    NASA Astrophysics Data System (ADS)

    Werner, C.; Preiß, G.; Gores, F.; Griebenow, M.; Heitmann, S.

    2016-08-01

    Multifunctional fuel cell systems are competitive solutions aboard future generations of civil aircraft concerning energy consumption, environmental issues, and safety reasons. The present study compares low-pressure and supercharged operation of polymer electrolyte membrane fuel cells with respect to performance and efficiency criteria. This is motivated by the challenge of pressure-dependent fuel cell operation aboard aircraft with cabin pressure varying with operating altitude. Experimental investigations of low-pressure fuel cell operation use model-based design of experiments and are complemented by numerical investigations concerning supercharged fuel cell operation. It is demonstrated that a low-pressure operation is feasible with the fuel cell device under test, but that its range of stable operation changes between both operating modes. Including an external compressor, it can be shown that the power demand for supercharging the fuel cell is about the same as the loss in power output of the fuel cell due to low-pressure operation. Furthermore, the supercharged fuel cell operation appears to be more sensitive with respect to variations in the considered independent operating parameters load requirement, cathode stoichiometric ratio, and cooling temperature. The results indicate that a pressure-dependent self-humidification control might be able to exploit the potential of low-pressure fuel cell operation for aircraft applications to the best advantage.

  12. Developments in Stochastic Fuel Efficient Cruise Control and Constrained Control with Applications to Aircraft

    NASA Astrophysics Data System (ADS)

    McDonough, Kevin K.

    The dissertation presents contributions to fuel-efficient control of vehicle speed and constrained control with applications to aircraft. In the first part of this dissertation a stochastic approach to fuel-efficient vehicle speed control is developed. This approach encompasses stochastic modeling of road grade and traffic speed, modeling of fuel consumption through the use of a neural network, and the application of stochastic dynamic programming to generate vehicle speed control policies that are optimized for the trade-off between fuel consumption and travel time. The fuel economy improvements with the proposed policies are quantified through simulations and vehicle experiments. It is shown that the policies lead to the emergence of time-varying vehicle speed patterns that are referred to as time-varying cruise. Through simulations and experiments it is confirmed that these time-varying vehicle speed profiles are more fuel-efficient than driving at a comparable constant speed. Motivated by these results, a simpler implementation strategy that is more appealing for practical implementation is also developed. This strategy relies on a finite state machine and state transition threshold optimization, and its benefits are quantified through model-based simulations and vehicle experiments. Several additional contributions are made to approaches for stochastic modeling of road grade and vehicle speed that include the use of Kullback-Liebler divergence and divergence rate and a stochastic jump-like model for the behavior of the road grade. In the second part of the dissertation, contributions to constrained control with applications to aircraft are described. Recoverable sets and integral safe sets of initial states of constrained closed-loop systems are introduced first and computational procedures of such sets based on linear discrete-time models are given. The use of linear discrete-time models is emphasized as they lead to fast computational procedures. Examples of

  13. Speciation of gas-phase and fine particle emissions from burning of foliar fuels.

    PubMed

    Hays, Michael D; Geron, Christopher D; Linna, Kara J; Smith, N Dean; Schauer, James J

    2002-06-01

    Fine particle matter with aerodynamic diameter <2.5 microm (PM2.5) and gas-phase emissions from open burning of six fine (foliar) fuels common to fire-prone U.S. ecosystems are investigated. PM2.5 distribution is unimodal within the 10-450 nm range, indicative of an accumulation mode. Smoldering relative to flaming combustion shows smaller particle number density per unit time and median size. Over 100 individual organic compounds in the primarily carbonaceous (>70% by mass) PM2.5 are chemically speciated by gas chromatography/mass spectrometry. Expressed as a percent of PM2.5 mass, emission ranges by organic compound class are as follows: n-alkane (0.1-2%), polycyclic aromatic hydrocarbon (PAH) (0.02-0.2%), n-alkanoic acid (1-3%), n-alkanedioic acid (0.06-0.3%), n-alkenoic acid (0.3-3%), resin acid (0.5-6%), triterpenoid (0.2-0.5%), methoxyphenol (0.5-3%), and phytosterol (0.2-0.6%). A molecular tracer of biomass combustion, the sugar levoglucosan is abundant and constitutes a remarkably narrow PM2.5 mass range (2.8-3.6%). Organic chemical signatures in PM2.5 from open combustion of fine fuels differ with those of residential wood combustion and other related sources, making them functional for source-receptor modeling of PM. Inorganic matter [PM2.5 - (organic compounds + elemental carbon)] on average is estimated to make up 8% of the PM2.5. Wavelength dispersive X-ray fluorescence spectroscopy and ion chromatography identify 3% of PM2.5 as elements and water-soluble ions, respectively. Compared with residential wood burning, the PM2.5 of fine fuel combustion is nitrate enriched but shows lower potassium levels. Gas-phase C2-C13 hydrocarbon and C2-C9 carbonyl emissions are speciated by respective EPA Methods T0-15 and T0-11A. They comprise mainly low molecular weight C2-C3 compounds and hazardous air pollutants (48 wt % of total quantified volatile organic carbon).

  14. Contributions from transport, solid fuel burning and cooking to primary organic aerosols in two UK cities

    NASA Astrophysics Data System (ADS)

    Allan, J. D.; Williams, P. I.; Morgan, W. T.; Martin, C. L.; Flynn, M. J.; Lee, J.; Nemitz, E.; Phillips, G. J.; Gallagher, M. W.; Coe, H.

    2010-01-01

    Organic matter frequently represents the single largest fraction of fine particulates in urban environments and yet the exact contributions from different sources and processes remain uncertain, owing in part to its substantial chemical complexity. Positive Matrix Factorisation (PMF) has recently proved to be a powerful tool for the purposes of source attribution and profiling when applied to ambient organic aerosol data from the Aerodyne Aerosol Mass Spectrometer (AMS). Here we present PMF analysis applied to AMS data from UK cities for the first time. Three datasets are analysed, with the focus on objectivity and consistency. The data were collected in London during the Regent's Park and Tower Environmental Experiment (REPARTEE) intensives and Manchester. These occurred during the autumn and wintertime, such that the primary fraction would be prominent. Ambiguities associated with rotationality within sets of potential solutions are explored and the most appropriate solution sets selected based on comparisons with external data. In addition to secondary organic aerosols, three candidate sources of primary organic aerosol (POA) were identified according to mass spectral and diurnal profiles; traffic emissions, cooking and solid fuel burning (for space heating). Traffic represented, on average, 40% of POA during colder conditions and exhibited a hydrocarbon-like mass spectrum similar to those previously reported. Cooking aerosols represented 34% of POA and through laboratory work, their profile was matched with that sampled from the heating of seed oils, rather than previously-published spectra derived from charbroiling. This suggests that in these locations, oil from frying may have contributed more to the particulate than the meat itself. Solid fuel aerosols represented 26% of POA during cold weather conditions but were not discernable during the first REPARTEE campaign, when conditions were warmer than the other campaigns. This factor showed features associated

  15. Carbon dioxide releases from fossil-fuel burning: Statement before the Senate Committee on Energy and Natural Resources

    SciTech Connect

    Marland G.; Boden, T.

    1989-07-26

    Discussion of the anthropogenic emissions of carbon dioxide to the atmosphere is given. There are three kinds of human activity that are currently resulting in net release of carbon dioxide (CO/sub 2/) to the atmosphere: burning fossil fuels, converting tropical forest area to other land use, and manufacturing cement. Although it is a comparatively small source of CO/sub 2/, cement manufacture involves the calcining of limestone (calcium carbonate) to produce calcium oxide. The associated CO/sub 2/ emissions are included in the figures that follow. Production of one metric ton of cement results in the release of 0.136 metric tons of carbon as CO/sub 2/. (This does not count the fuel used in the processing). When forest area is cleared and converted to land uses that have smaller inventories of carbon in the biota and in the surface liter and soil, there is a net release of carbon to become CO/sub 2/ in the atmosphere. Every cubic meter of timber burned releases about 0.26 metric tons of carbon as CO/sub 2/ to the atmosphere, and forest clearing generally results in a release of additional carbon from the soil and surface litter. When fossil fuels are burned, carbon that has been long stored in the earth is oxidized and released to the atmosphere as CO/sub 2/. Because fossil-fuel burning releases heat from the oxidation of both carbon (to produce carbon dioxide) and hydrogen (to produce water), and because the different fuel forms contain different ratios of carbon to hydrogen, the amount of CO/sub 2/ produced per unit of energy released is different for the various fuel forms. 14 figs.

  16. Year 2015 Aircraft Emission Scenario for Scheduled Air Traffic

    NASA Technical Reports Server (NTRS)

    Baughcum, Steven L.; Sutkus, Donald J.; Henderson, Stephen C.

    1998-01-01

    This report describes the development of a three-dimensional scenario of aircraft fuel burn and emissions (fuel burned, NOx, CO, and hydrocarbons)for projected year 2015 scheduled air traffic. These emission inventories are available for use by atmospheric scientists conducting the Atmospheric Effects of Aviation Project (AEAP) modeling studies. Fuel burned and emissions of nitrogen oxides (NOx as NO2), carbon monoxides, and hydrocarbons have been calculated on a 1 degree latitude x 1 degree longitude x 1 kilometer altitude grid and delivered to NASA as electronic files.

  17. Impacts of alternative fuels in aviation on microphysical aerosol properties and predicted ice nuclei concentration at aircraft cruise altitude

    NASA Astrophysics Data System (ADS)

    Weinzierl, B.; D'Ascoli, E.; Sauer, D. N.; Kim, J.; Scheibe, M.; Schlager, H.; Moore, R.; Anderson, B. E.; Ullrich, R.; Mohler, O.; Hoose, C.

    2015-12-01

    In the past decades air traffic has been substantially growing affecting air quality and climate. According to the International Civil Aviation Authority (ICAO), in the next few years world passenger and freight traffic is expected to increase annually by 6-7% and 4-5%, respectively. One possibility to reduce aviation impacts on the atmosphere and climate might be the replacement of fossil fuels by alternative fuels. However, so far the effects of alternative fuels on particle emissions from aircraft engines and their ability to form contrails remain uncertain. To study the effects of alternative fuels on particle emissions and the formation of contrails, the Alternative Fuel Effects on Contrails and Cruise Emissions (ACCESS) field experiment was conducted in California. In May 2014, the DLR Falcon 20 and the NASA HU-25 jet aircraft were instrumented with an extended aerosol and trace gas payload probing different types of fuels including JP-8 and JP-8 blended with HEFA (Hydroprocessed Esters and Fatty Acids) while the NASA DC8 aircraft acted as the source aircraft for ACCESS-2. Emission measurements were taken in the DC8 exhaust plumes at aircraft cruise level between 9-12 km altitude and at distances between 50 m and 20 km behind the DC8 engines. Here, we will present results from the ACCESS-2 aerosol measurements which show a 30-60% reduction of the non-volatile (mainly black carbon) particle number concentration in the aircraft exhaust for the HEFA-blend compared to conventional JP-8 fuel. Size-resolved particle emission indices show the largest reductions for larger particle sizes suggesting that the HEFA blend contains fewer and smaller black carbon particles. We will combine the airborne measurements with a parameterization of deposition nucleation developed during a number of ice nucleation experiments at the AIDA chamber in Karlsruhe and discuss the impact of alternative fuels on the abundance of potential ice nuclei at cruise conditions.

  18. Fuel Consumption Modeling of a Transport Category Aircraft Using Flight Operations Quality Assurance Data: A Literature Review

    NASA Technical Reports Server (NTRS)

    Stolzer, Alan J.

    2002-01-01

    Fuel is a major cost expense for air carriers. A typical airline spends 10% of its operating budget on the purchase of jet fuel, which even exceeds its expenditures on aircraft acquisitions. Thus, it is imperative that fuel consumption be managed as wisely as possible. The implementation of Flight Operations Quality Assurance (FOQA) programs at airlines may be able to assist in this management effort. The purpose of the study is to examine the literature regarding fuel consumption by air carriers, the literature related to air carrier fuel conservation efforts, and the literature related to the appropriate statistical methodologies to analyze the FOQA-derived data.

  19. Fuel containment and damage tolerance in large composite primary aircraft structures

    NASA Technical Reports Server (NTRS)

    Griffin, C. F.

    1983-01-01

    Technical problems related to fuel containment and damage tolerance of composite material wings for transport aircraft was investigated. The major tasks are the following: (1) the preliminary design of damage tolerant wing surface using composite materials; (2) the evaluation of fuel sealing and lightning protection methods for a composite material wing; and (3) an experimental investigation of the damage tolerant characteristics of toughened resin graphite/epoxy materials. The design concepts investigated for the upper and lower surfaces of a composite wing for a transport aircraft are presented and the relationship between weight savings and the design allowable strain used within the analysis is discussed. Experiments which compare the fuel sealing characteristics of bolt-bonded joints and bolted joints sealed with a polysulphide sealant are reviewed. Data from lightning strike tests on stiffened and unstiffened graphite/epoxy panels are presented. A wide variety of coupon tests were conducted to evaluate the relative damage tolerance of toughened resin graphite/epoxies. Data from these tests are presented and their relevance to the wing surface design concepts are discussed.

  20. Aircraft observations of biomass burning emissions in the lower stratosphere during the Deep Convective Clouds and Chemistry Experiment (DC3)

    NASA Astrophysics Data System (ADS)

    Knapp, D. J.; Montzka, D.; Campos, T. L.; Flocke, F. M.; Stechman, D.; Farris, C.; Rooney, M.; Pan, L.; Apel, E. C.; Hornbrook, R. S.; Riemer, D. D.; Chen, D.; Huey, L. G.; Brock, C. A.; Froyd, K. D.; Liao, J.; Murphy, D. M.; Ryerson, T. B.; Dibb, J. E.; Scheuer, E. M.; Diskin, G. S.; Sachse, G. W.; Gao, R.; Langridge, J. M.; Hair, J. W.; Butler, C. F.; Fenn, M. A.; Fromm, M. D.; Lindsey, D.; Weinheimer, A. J.

    2012-12-01

    During test flights for the Deep Convective Clouds and Chemistry Experiment conducted in May and June of 2012, clear indications of biomass burning (BB) were observed in the Lower Stratosphere (LS). Enhancements in CO, aerosols, and CH3CN substantiate the impact of BB effluents on the studied air mass. A large complex of fires southwest of Lake Baikal in Russia had been observed to flare up significantly on May 7, 2012, leading to a strong Aerosol Index signature. The aerosol plume was tracked using AURA Ozone Monitoring Instrument (OMI) and Cloud-Aerosol LIDAR and Infrared Pathfinder Satellite Observations (CALIPSO) curtains from the Baikal area, over Northern Siberia, the Aleutian Islands, South Western Canada and ultimately to the DC3 flight study area on May 14, 2012. BB tracers were sampled from the NASA DC8 and the NSF GV aircraft over a lateral range of 600km and an altitude of approximately 11.7 km which is approximately 0.5 km to 1.0 km above the local cold point tropopause.

  1. Fuel containment and damage tolerance in large composite primary aircraft structures. Phase 2: Testing

    NASA Technical Reports Server (NTRS)

    Sandifer, J. P.; Denny, A.; Wood, M. A.

    1985-01-01

    Technical issues associated with fuel containment and damage tolerance of composite wing structures for transport aircraft were investigated. Material evaluation tests were conducted on two toughened resin composites: Celion/HX1504 and Celion/5245. These consisted of impact, tension, compression, edge delamination, and double cantilever beam tests. Another test series was conducted on graphite/epoxy box beams simulating a wing cover to spar cap joint configuration of a pressurized fuel tank. These tests evaluated the effectiveness of sealing methods with various fastener types and spacings under fatigue loading and with pressurized fuel. Another test series evaluated the ability of the selected coatings, film, and materials to prevent fuel leakage through 32-ply AS4/2220-1 laminates at various impact energy levels. To verify the structural integrity of the technology demonstration article structural details, tests were conducted on blade stiffened panels and sections. Compression tests were performed on undamaged and impacted stiffened AS4/2220-1 panels and smaller element tests to evaluate stiffener pull-off, side load and failsafe properties. Compression tests were also performed on panels subjected to Zone 2 lightning strikes. All of these data were integrated into a demonstration article representing a moderately loaded area of a transport wing. This test combined lightning strike, pressurized fuel, impact, impact repair, fatigue and residual strength.

  2. Simulation of Hydrodynamic RAM of Aircraft Fuel Tank by Ballistic Penetration and Detonation

    NASA Astrophysics Data System (ADS)

    Kim, Jong H.; Jun, Seung M.

    Airframe survivability and hydrodynamic ram effect of aircraft are investigated. Penetration and internal detonation of a simple tank and ICW(Intermediate Complexity Wing) are simulated by nonlinear explicit calculation. Structural rupture and fluid burst are analytically realized using general coupling of FSI(Fluid-Structure Interaction) and adaptive master-slave contact. Besides, multi-material Eulerian solver and porosity algorithm are employed to model explosive inside fuel and tank bays which are defined in multi-coupling surfaces. Structure and fluid results are animated on the same viewport for enhanced visualization.

  3. An Experimental Study of Upward Burning Over Long Solid Fuels: Facility Development and Comparison

    NASA Technical Reports Server (NTRS)

    Kleinhenz, Julie; Yuan, Zeng-Guang

    2011-01-01

    As NASA's mission evolves, new spacecraft and habitat environments necessitate expanded study of materials flammability. Most of the upward burning tests to date, including the NASA standard material screening method NASA-STD-6001, have been conducted in small chambers where the flame often terminates before a steady state flame is established. In real environments, the same limitations may not be present. The use of long fuel samples would allow the flames to proceed in an unhindered manner. In order to explore sample size and chamber size effects, two large chambers were developed at NASA GRC under the Flame Prevention, Detection and Suppression (FPDS) project. The first was an existing vacuum facility, VF-13, located at NASA John Glenn Research Center. This 6350 liter chamber could accommodate fuels sample lengths up to 2 m. However, operational costs and restricted accessibility limited the test program, so a second laboratory scale facility was developed in parallel. By stacking additional two chambers on top of an existing combustion chamber facility, this 81 liter Stacked-chamber facility could accommodate a 1.5 m sample length. The larger volume, more ideal environment of VF-13 was used to obtain baseline data for comparison with the stacked chamber facility. In this way, the stacked chamber facility was intended for long term testing, with VF-13 as the proving ground. Four different solid fuels (adding machine paper, poster paper, PMMA plates, and Nomex fabric) were tested with fuel sample lengths up to 2 m. For thin samples (papers) with widths up to 5 cm, the flame reached a steady state length, which demonstrates that flame length may be stabilized even when the edge effects are reduced. For the thick PMMA plates, flames reached lengths up to 70 cm but were highly energetic and restricted by oxygen depletion. Tests with the Nomex fabric confirmed that the cyclic flame phenomena, observed in small facility tests, continued over longer sample. New

  4. Examination of the costs, benefits and enery conservation aspects of the NASA aircraft fuel conservation technology program

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The costs and benefits of the NASA Aircraft Fuel Conservation Technology Program are discussed. Consideration is given to a present worth analysis of the planned program expenditures, an examination of the fuel savings to be obtained by the year 2005 and the worth of this fuel savings relative to the investment required, a comparison of the program funding with that planned by other Federal agencies for energy conservation, an examination of the private industry aeronautical research and technology financial posture for the period FY 76 - FY 85, and an assessment of the potential impacts on air and noise pollution. To aid in this analysis, a computerized fleet mix forecasting model was developed. This model enables the estimation of fuel consumption and present worth of fuel expenditures for selected commerical aircraft fleet mix scenarios.

  5. Powder Metallurgy of Uranium Alloy Fuels for TRU-Burning Reactors Final Technical Report

    SciTech Connect

    McDeavitt, Sean M

    2011-04-29

    outlining the beginning of the materials processing setup. Also included within this section is a thesis proposal by Jeff Hausaman. Appendix C contains the public papers and presentations introduced at the 2010 American Nuclear Society Winter Meeting. Appendix A—MSNE theses of David Garnetti and Grant Helmreich and proposal by Jeff Hausaman A.1 December 2009 Thesis by David Garnetti entitled “Uranium Powder Production Via Hydride Formation and Alpha Phase Sintering of Uranium and Uranium-Zirconium Alloys for Advanced Nuclear Fuel Applications” A.2 September 2009 Presentation by David Garnetti (same title as document in Appendix B.1) A.3 December 2010 Thesis by Grant Helmreich entitled “Characterization of Alpha-Phase Sintering of Uranium and Uranium-Zirconium Alloys for Advanced Nuclear Fuel Applications” A.4 October 2010 Presentation by Grant Helmreich (same title as document in Appendix B.3) A.5 Thesis Proposal by Jeffrey Hausaman entitled “Hot Extrusion of Alpha Phase Uranium-Zirconium Alloys for TRU Burning Fast Reactors” Appendix B—External presentations introduced at the 2010 ANS Winter Meeting B.1 J.S. Hausaman, D.J. Garnetti, and S.M. McDeavitt, “Powder Metallurgy of Alpha Phase Uranium Alloys for TRU Burning Fast Reactors,” Proceedings of 2010 ANS Winter Meeting, Las Vegas, Nevada, USA, November 7-10, 2010 B.2 PowerPoint Presentation Slides from C.1 B.3 G.W. Helmreich, W.J. Sames, D.J. Garnetti, and S.M. McDeavitt, “Uranium Powder Production Using a Hydride-Dehydride Process,” Proceedings of 2010 ANS Winter Meeting, Las Vegas, Nevada, USA, November 7-10, 2010 B.4. PowerPoint Presentation Slides from C.3 B.5 Poster Presentation from C.3 Appendix C—Fuel cycle research and development undergraduate materials and poster presentation C.1 Poster entitled “Characterization of Alpha-Phase Sintering of Uranium and Uranium-Zirconium Alloys” presented at the Fuel Cycle Technologies Program Annual Meeting C.2 April 2011 Honors Undergraduate Thesis

  6. Electrical Generation for More-Electric Aircraft Using Solid Oxide Fuel Cells

    SciTech Connect

    Whyatt, Greg A.; Chick, Lawrence A.

    2012-04-01

    This report examines the potential for Solid-Oxide Fuel Cells (SOFC) to provide electrical generation on-board commercial aircraft. Unlike a turbine-based auxiliary power unit (APU) a solid oxide fuel cell power unit (SOFCPU) would be more efficient than using the main engine generators to generate electricity and would operate continuously during flight. The focus of this study is on more-electric aircraft which minimize bleed air extraction from the engines and instead use electrical power obtained from generators driven by the main engines to satisfy all major loads. The increased electrical generation increases the potential fuel savings obtainable through more efficient electrical generation using a SOFCPU. However, the weight added to the aircraft by the SOFCPU impacts the main engine fuel consumption which reduces the potential fuel savings. To investigate these relationships the Boeing 787­8 was used as a case study. The potential performance of the SOFCPU was determined by coupling flowsheet modeling using ChemCAD software with a stack performance algorithm. For a given stack operating condition (cell voltage, anode utilization, stack pressure, target cell exit temperature), ChemCAD software was used to determine the cathode air rate to provide stack thermal balance, the heat exchanger duties, the gross power output for a given fuel rate, the parasitic power for the anode recycle blower and net power obtained from (or required by) the compressor/expander. The SOFC is based on the Gen4 Delphi planar SOFC with assumed modifications to tailor it to this application. The size of the stack needed to satisfy the specified condition was assessed using an empirically-based algorithm. The algorithm predicts stack power density based on the pressure, inlet temperature, cell voltage and anode and cathode inlet flows and compositions. The algorithm was developed by enhancing a model for a well-established material set operating at atmospheric pressure to reflect the

  7. Fuel containment, lightning protection and damage tolerance in large composite primary aircraft structures

    NASA Technical Reports Server (NTRS)

    Griffin, Charles F.; James, Arthur M.

    1985-01-01

    The damage-tolerance characteristics of high strain-to-failure graphite fibers and toughened resins were evaluated. Test results show that conventional fuel tank sealing techniques are applicable to composite structures. Techniques were developed to prevent fuel leaks due to low-energy impact damage. For wing panels subjected to swept stroke lightning strikes, a surface protection of graphite/aluminum wire fabric and a fastener treatment proved effective in eliminating internal sparking and reducing structural damage. The technology features developed were incorporated and demonstrated in a test panel designed to meet the strength, stiffness, and damage tolerance requirements of a large commercial transport aircraft. The panel test results exceeded design requirements for all test conditions. Wing surfaces constructed with composites offer large weight savings if design allowable strains for compression can be increased from current levels.

  8. Study of LH2-fueled topping cycle engine for aircraft propulsion

    NASA Technical Reports Server (NTRS)

    Turney, G. E.; Fishbach, L. H.

    1983-01-01

    An analytical investigation was made of a topping cycle aircraft engine system which uses a cryogenic fuel. This system consists of a main turboshaft engine which is mechanically coupled (by cross-shafting) to a topping loop which augments the shaft power output of the system. The thermodynamic performance of the topping cycle engine was analyzed and compared with that of a reference (conventional-type) turboshaft engine. For the cycle operating conditions selected, the performance of the topping cycle engine in terms of brake specific fuel consumption (bsfc) was determined to be about 12 percent better than that of the reference turboshaft engine. Engine weights were estimated for both the topping cycle engine and the reference turboshaft engine. These estimates were based on a common shaft power output for each engine. Results indicate that the weight of the topping cycle engine is comparable to that of the reference turboshaft engine.

  9. Probing Aircraft Flight Test Hazard Mitigation for the Alternative Fuel Effects on Contrails & Cruise Emissions (ACCESS) Research Team

    NASA Technical Reports Server (NTRS)

    Kelly, Michael J.

    2013-01-01

    The Alternative Fuel Effects on Contrails & Cruise Emissions (ACCESS) Project Integration Manager requested in July 2012 that the NASA Engineering and Safety Center (NESC) form a team to independently assess aircraft structural failure hazards associated with the ACCESS experiment and to identify potential flight test hazard mitigations to ensure flight safety. The ACCESS Project Integration Manager subsequently requested that the assessment scope be focused predominantly on structural failure risks to the aircraft empennage raft empennage.

  10. Biodegradation of international jet A-1 aviation fuel by microorganisms isolated from aircraft tank and joint hydrant storage systems.

    PubMed

    Itah, A Y; Brooks, A A; Ogar, B O; Okure, A B

    2009-09-01

    Microorganisms contaminating international Jet A-1 aircraft fuel and fuel preserved in Joint Hydrant Storage Tank (JHST) were isolated, characterized and identified. The isolates were Bacillus subtillis, Bacillus megaterium, Flavobacterium oderatum, Sarcina flava, Micrococcus varians, Pseudomonas aeruginosa, Bacillus licheniformis, Bacillus cereus and Bacillus brevis. Others included Candida tropicalis, Candida albicans, Saccharomyces estuari, Saccharomyces cerevisiae, Schizosaccharomyces pombe, Aspergillus flavus, Aspergillus niger, Aspergillus fumigatus, Cladosporium resinae, Penicillium citrinum and Penicillium frequentans. The viable plate count of microorganisms in the Aircraft Tank ranged from 1.3 (+/-0.01) x 104 cfu/mL to 2.2 (+/-1.6) x 104 cfu/mL for bacteria and 102 cfu/mL to 1.68 (+/-0.32) x 103 cfu/mL for fungi. Total bacterial counts of 1.79 (+/-0.2) x 104 cfu/mL to 2.58 (+/-0.04) x 104 cfu/mL and total fungal count of 2.1 (+/-0.1) x 103 cfu/mL to 2.28 (+/-0.5) x 103 cfu/mL were obtained for JHST. Selected isolates were re-inoculated into filter sterilized aircraft fuels and biodegradation studies carried out. After 14 days incubation, Cladosporium resinae exhibited the highest degradation rate with a percentage weight loss of 66 followed by Candida albicans (60.6) while Penicillium citrinum was the least degrader with a weight loss of 41.6%. The ability of the isolates to utilize the fuel as their sole source of carbon and energy was examined and found to vary in growth profile between the isolates. The results imply that aviation fuel could be biodegraded by hydrocarbonoclastic microorganisms. To avert a possible deterioration of fuel quality during storage, fuel pipe clogging and failure, engine component damage, wing tank corrosion and aircraft disaster, efficient routine monitoring of aircraft fuel systems is advocated.

  11. Response of the global climate to changes in atmospheric chemical composition due to fossil fuel burning

    NASA Technical Reports Server (NTRS)

    Cess, R. D.; Hameed, S.; Hogan, J. S.

    1980-01-01

    Tropospheric ozone and methane might increase in the future as the result of increasing anthropogenic emissions of CO, NOx and CH4 due to fossil fuel burning. Since O3 and CH4 are both greenhouse gases, increases in their concentrations could augment global warming due to larger future amounts of atmospheric CO2. To test this possible climatic impact, a zonal energy-balance climate model has been combined with a vertically-averaged tropospheric chemical model. The latter model includes all relevant chemical reactions which affect species derived from H2O, O2, CH4 and NOx. The climate model correspondingly incorporates changes in the infrared heating of the surface-troposphere system resulting from chemically induced changes in tropospheric ozone and methane. This coupled climate-chemical model indicates that global climate is sensitive to changes in emissions of CO, NOx and CH4, and that future increases in these emissions could enhance global warming due to increasing atmospheric CO2.

  12. Response of the global climate to changes in atmospheric chemical composition due to fossil fuel burning

    NASA Technical Reports Server (NTRS)

    Hameed, S.; Cess, R. D.; Hogan, J. S.

    1980-01-01

    Recent modeling of atmospheric chemical processes (Logan et al, 1978; Hameed et al, 1979) suggests that tropospheric ozone and methane might significantly increase in the future as the result of increasing anthropogenic emissions of CO, NO(x), and CH4 due to fossil fuel burning. Since O3 and CH4 are both greenhouse gases, increases in their concentrations could augment global warming due to larger future amounts of atmospheric CO2. To test the possible climatic impact of changes in tropospheric chemical composition, a zonal energy-balance climate model has been combined with a vertically averaged tropospheric chemical model. The latter model includes all relevant chemical reactions which affect species derived from H2O, O2, CH4, and NO(x). The climate model correspondingly incorporates changes in the infrared heating of the surface-troposphere system resulting from chemically induced changes in tropospheric ozone and methane. This coupled climate-chemical model indicates that global climate is sensitive to changes in emissions of CO, NO(x) and CH4, and that future increases in these emissions could augment global warming due to increasing atmospheric CO2.

  13. Coupled Mechanisms of Precipitation and Atomization in Burning Nanofluid Fuel Droplets

    PubMed Central

    Miglani, Ankur; Basu, Saptarshi

    2015-01-01

    Understanding the combustion characteristics of fuel droplets laden with energetic nanoparticles (NP) is pivotal for lowering ignition delay, reducing pollutant emissions and increasing the combustion efficiency in next generation combustors. In this study, first we elucidate the feedback coupling between two key interacting mechanisms, namely, secondary atomization and particle agglomeration; that govern the effective mass fraction of NPs within the droplet. Second, we show how the initial NP concentration modulates their relative dominance leading to a master-slave configuration. Secondary atomization of novel nanofuels is a crucial process since it enables an effective transport of dispersed NPs to the flame (a pre-requisite condition for NPs to burn). Contrarily, NP agglomeration at the droplet surface leads to shell formation thereby retaining NPs inside the droplet. In particular, we show that at dense concentrations shell formation (master process) dominates over secondary atomization (slave) while at dilute particle loading it is the high frequency bubble ejections (master) that disrupt shell formation (slave) through its rupture and continuous outflux of NPs. This results in distinct combustion residues at dilute and dense concentrations, thereby providing a method of manufacturing flame synthesized microstructures with distinct morphologies. PMID:26446366

  14. Performance assessment for the geological disposal of Deep Burn spent fuel using TTBX

    SciTech Connect

    Van den Akker, B.P.; Ahn, J.

    2013-07-01

    The behavior of Deep Burn Modular High Temperature Reactor Spent Fuel (DBSF) is investigated in the Yucca Mountain geological repository (YMR) with respect to the annual dose (Sv/yr) delivered to the Reasonably Maximally Exposed Individual (RMEI) from the transport of radionuclides released from the graphite waste matrix. Transport calculations are performed with a novel computer code, TTBX which is capable of modeling transport pathways that pass through heterogeneous geological formations. TTBX is a multi-region extension of the existing single region TTB transport code. Overall the peak annual dose received by the RMEI is seen to be four orders of magnitude lower than the regulatory threshold for exposure, even under pessimistic scenarios. A number of factors contribute to the favorable performance of DBSF. A reduction of one order of magnitude in the peak annual dose received by the RMEI is observed for every order of magnitude increase in the waste matrix lifetime, highlighting the importance of the waste matrix durability and suggesting graphite's utility as a potential waste matrix for the disposal of high-level waste. Furthermore, we see that by incorporating a higher fidelity far-field model the peak annual dose calculated to be received by the RMEI is reduced by two orders of magnitude. By accounting for the heterogeneities of the far field we have simultaneously removed unnecessary conservatisms and improved the fidelity of the transport model. (authors)

  15. Evaporation and burning of a spherical fuel droplet in a uniform convective flowfield

    SciTech Connect

    Madooglu, K.

    1992-01-01

    An analytical/numerical model is developed for the evaporation and burning of a spherical fuel droplet in a subsonic crossflow. The external gaseous flowfield is represented using an approximate compressible potential-flow solution, while the internal flowfield of the droplet is represented by the classical Hill's spherical vortex. This allows a numerical solution for the external boundary layer, from which the droplet's effective drag coefficent, rate of mass loss, size, and the shape of the diffusion flame with infinitely fast chemical reaction kinetics are determined. Subsequently, the quasi-steady model with uniform liquid temperature is extended to examine the effects of the transient heating of the droplet interior. Time-dependent calculations are performed with updated droplet Reynolds numbers and updated surface temperatures. Comparisons of model predictions with experimental data are made. To examine the effects of finite-rate chemical reaction kinetics, a one-step formulation of the combustion mechanism is integrated into the gaseous boundary layer equations. Simplifying assumptions for the variation of gas properties commonly used in combustion calculations, are subjected to an examination as to their degree of accuracy. For this purpose, the droplet model is extended to account for the variation of gas properties with temperature and gas composition within the boundary layer. Comparisons are made between the predictions obtained from the different models developed in this study, as well as with existing experimental data.

  16. Transverse liquid fuel jet breakup, burning, and ignition. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Li, Hsi-Shang

    1990-01-01

    An analytical study of the breakup, burning, and ignition of liquid fuels injected transversely into a hot air stream is conducted. The non-reacting liquid jet breakup location is determined by the local sonic point criterion. Two models, one employing analysis of an elliptical jet cross-section and the other employing a two-dimensional blunt body to represent the transverse jet, were used for sonic point calculations. An auxiliary criterion based on surface tension stability is used as a separate means of determining the breakup location. For the reacting liquid jet problem, a diffusion flame supported by a one-step chemical reaction within the gaseous boundary layer is solved along the ellipse surface in subsonic cross flow. Typical flame structures and concentration profiles were calculated for various locations along the jet cross-section as a function of upstream Mach numbers. The integration reaction rate along the jet cross-section is used to predict ignition position, which is found to be situated near the stagnation point. While a multi-step reaction is needed to represent the ignition process more accurately, the present calculation does yield reasonable predictions concerning ignition along a curved surface.

  17. Engine-integrated solid oxide fuel cells for efficient electrical power generation on aircraft

    NASA Astrophysics Data System (ADS)

    Waters, Daniel F.; Cadou, Christopher P.

    2015-06-01

    This work investigates the use of engine-integrated catalytic partial oxidation (CPOx) reactors and solid oxide fuel cells (SOFCs) to reduce fuel burn in vehicles with large electrical loads like sensor-laden unmanned air vehicles. Thermodynamic models of SOFCs, CPOx reactors, and three gas turbine (GT) engine types (turbojet, combined exhaust turbofan, separate exhaust turbofan) are developed and checked against relevant data and source material. Fuel efficiency is increased by 4% and 8% in the 50 kW and 90 kW separate exhaust turbofan systems respectively at only modest cost in specific power (8% and 13% reductions respectively). Similar results are achieved in other engine types. An additional benefit of hybridization is the ability to provide more electric power (factors of 3 or more in some cases) than generator-based systems before encountering turbine inlet temperature limits. A sensitivity analysis shows that the most important parameters affecting the system's performance are operating voltage, percent fuel oxidation, and SOFC assembly air flows. Taken together, this study shows that it is possible to create a GT-SOFC hybrid where the GT mitigates balance of plant losses and the SOFC raises overall system efficiency. The result is a synergistic system with better overall performance than stand-alone components.

  18. Evaluation of a Hydrogen Fuel Cell Powered Blended-Wing-Body Aircraft Concept for Reduced Noise and Emissions

    NASA Technical Reports Server (NTRS)

    Guynn, Mark D.; Freh, Joshua E.; Olson, Erik D.

    2004-01-01

    This report describes the analytical modeling and evaluation of an unconventional commercial transport aircraft concept designed to address aircraft noise and emission issues. A blended-wing-body configuration with advanced technology hydrogen fuel cell electric propulsion is considered. Predicted noise and emission characteristics are compared to a current technology conventional configuration designed for the same mission. The significant technology issues which have to be addressed to make this concept a viable alternative to current aircraft designs are discussed. This concept is one of the "Quiet Green Transport" aircraft concepts studied as part of NASA's Revolutionary Aerospace Systems Concepts (RASC) Program. The RASC Program was initiated to develop revolutionary concepts that address strategic objectives of the NASA Enterprises, such as reducing aircraft noise and emissions, and to identify advanced technology requirements for the concepts.

  19. Evaluation of an Aircraft Concept With Over-Wing, Hydrogen-Fueled Engines for Reduced Noise and Emissions

    NASA Technical Reports Server (NTRS)

    Guynn, Mark D.; Olson, Erik D.

    2002-01-01

    This report describes the analytical modeling and evaluation of an unconventional commercial transport aircraft concept designed to address aircraft noise and emission issues. A strut-braced wing configuration with overwing, ultra-high bypass ratio, hydrogen fueled turbofan engines is considered. Estimated noise and emission characteristics are compared to a conventional configuration designed for the same mission and significant benefits are identified. The design challenges and technology issues which would have to be addressed to make the concept a viable alternative to current aircraft designs are discussed. This concept is one of the "Quiet Green Transport" aircraft concepts studied as part of NASA's Revolutionary Aerospace Systems Concepts (RASC) Program. The RASC Program seeks to develop revolutionary concepts that address strategic objectives of the NASA Enterprises, such as reducing aircraft noise and emissions, and to identify enabling advanced technology requirements for the concepts.

  20. High Temperature Reactor (HTR) Deep Burn Core and Fuel Analysis: Design Selection for the Prismatic Block Reactor

    SciTech Connect

    Francesco Venneri; Chang-Keun Jo; Jae-Man Noh; Yonghee Kim; Claudio Filippone; Jonghwa Chang; Chris Hamilton; Young-Min Kim; Ji-Su Jun; Moon-Sung Cho; Hong-Sik Lim; MIchael A. Pope; Abderrafi M. Ougouag; Vincent Descotes; Brian Boer

    2010-09-01

    The Deep Burn (DB) Project is a U.S. Department of Energy sponsored feasibility study of Transuranic Management using high burnup fuel in the high temperature helium cooled reactor (HTR). The DB Project consists of seven tasks: project management, core and fuel analysis, spent fuel management, fuel cycle integration, TRU fuel modeling, TRU fuel qualification, and HTR fuel recycle. In the Phase II of the Project, we conducted nuclear analysis of TRU destruction/utilization in the HTR prismatic block design (Task 2.1), deep burn fuel/TRISO microanalysis (Task 2.3), and synergy with fast reactors (Task 4.2). The Task 2.1 covers the core physics design, thermo-hydraulic CFD analysis, and the thermofluid and safety analysis (low pressure conduction cooling, LPCC) of the HTR prismatic block design. The Task 2.3 covers the analysis of the structural behavior of TRISO fuel containing TRU at very high burnup level, i.e. exceeding 50% of FIMA. The Task 4.2 includes the self-cleaning HTR based on recycle of HTR-generated TRU in the same HTR. Chapter IV contains the design and analysis results of the 600MWth DB-HTR core physics with the cycle length, the average discharged burnup, heavy metal and plutonium consumptions, radial and axial power distributions, temperature reactivity coefficients. Also, it contains the analysis results of the 450MWth DB-HTR core physics and the analysis of the decay heat of a TRU loaded DB-HTR core. The evaluation of the hot spot fuel temperature of the fuel block in the DB-HTR (Deep-Burn High Temperature Reactor) core under full operating power conditions are described in Chapter V. The investigated designs are the 600MWth and 460MWth DB-HTRs. In Chapter VI, the thermo-fluid and safety of the 600MWth DB-HTRs has been analyzed to investigate a thermal-fluid design performance at the steady state and a passive safety performance during an LPCC event. Chapter VII describes the analysis results of the TRISO fuel microanalysis of the 600MWth and 450

  1. Aircraft

    DTIC Science & Technology

    2003-01-01

    national power. But with the recent events such as the war with Iraq, the Severe Acute Respiratory Syndrome (SARS) outbreak, some major carriers... TITLE AND SUBTITLE 2003 Industry Studies: Aircraft 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER

  2. Laboratory measurements of trace gas emissions from biomass burning of fuel types from the Southeastern and Southwestern United States

    NASA Astrophysics Data System (ADS)

    Burling, I. R.; Yokelson, R. J.; Griffith, D. W. T.; Johnson, T. J.; Veres, P.; Roberts, J. M.; Warneke, C.; Urbanski, S. P.; Reardon, J.; Weise, D. R.; Hao, W. M.; de Gouw, J.

    2010-07-01

    Vegetation commonly managed by prescribed burning was collected from five southeastern and southwestern US military bases and burned under controlled conditions at the US Forest Service Fire Sciences Laboratory in Missoula, Montana. The smoke emissions were measured with a large suite of state-of-the-art instrumentation including an open-path Fourier transform infrared (OP-FTIR) spectrometer for measurement of gas-phase species. The OP-FTIR detected and quantified 19 gas-phase species in these fires: CO2, CO, CH4, C2H2, C2H4, C3H6, HCHO, HCOOH, CH3OH, CH3COOH, furan, H2O, NO, NO2, HONO, NH3, HCN, HCl, and SO2. Emission factors for these species are presented for each vegetation type burned. Gas-phase nitrous acid (HONO), an important OH precursor, was detected in the smoke from all fires. The HONO emission factors ranged from 0.15 to 0.60 g kg-1 and were higher for the southeastern fuels. The fire-integrated molar emission ratios of HONO (relative to NOx) ranged from approximately 0.03 to 0.20, with higher values also observed for the southeastern fuels. The majority of non-methane organic compound (NMOC) emissions detected by OP-FTIR were oxygenated volatile organic compounds (OVOCs) with the total identified OVOC emissions constituting 61±12% of the total measured NMOC on a molar basis. These OVOC may undergo photolysis or further oxidation contributing to ozone formation. Elevated amounts of gas-phase HCl and SO2 were also detected during flaming combustion, with the amounts varying greatly depending on location and vegetation type. The fuels with the highest HCl emission factors were all located in the coastal regions, although HCl was also observed from fuels farther inland. Emission factors for HCl were generally higher for the southwestern fuels, particularly those found in the chaparral biome in the coastal regions of California.

  3. Laboratory measurements of trace gas emissions from biomass burning of fuel types from the southeastern and southwestern United States

    NASA Astrophysics Data System (ADS)

    Burling, I. R.; Yokelson, R. J.; Griffith, D. W. T.; Johnson, T. J.; Veres, P.; Roberts, J. M.; Warneke, C.; Urbanski, S. P.; Reardon, J.; Weise, D. R.; Hao, W. M.; de Gouw, J.

    2010-11-01

    Vegetation commonly managed by prescribed burning was collected from five southeastern and southwestern US military bases and burned under controlled conditions at the US Forest Service Fire Sciences Laboratory in Missoula, Montana. The smoke emissions were measured with a large suite of state-of-the-art instrumentation including an open-path Fourier transform infrared (OP-FTIR) spectrometer for measurement of gas-phase species. The OP-FTIR detected and quantified 19 gas-phase species in these fires: CO2, CO, CH4, C2H2, C2H4, C3H6, HCHO, HCOOH, CH3OH, CH3COOH, furan, H2O, NO, NO2, HONO, NH3, HCN, HCl, and SO2. Emission factors for these species are presented for each vegetation type burned. Gas-phase nitrous acid (HONO), an important OH precursor, was detected in the smoke from all fires. The HONO emission factors ranged from 0.15 to 0.60 g kg-1 and were higher for the southeastern fuels. The fire-integrated molar emission ratios of HONO (relative to NOx) ranged from approximately 0.03 to 0.20, with higher values also observed for the southeastern fuels. The majority of non-methane organic compound (NMOC) emissions detected by OP-FTIR were oxygenated volatile organic compounds (OVOCs) with the total identified OVOC emissions constituting 61 ± 12% of the total measured NMOC on a molar basis. These OVOC may undergo photolysis or further oxidation contributing to ozone formation. Elevated amounts of gas-phase HCl and SO2 were also detected during flaming combustion, with the amounts varying greatly depending on location and vegetation type. The fuels with the highest HCl emission factors were all located in the coastal regions, although HCl was also observed from fuels farther inland. Emission factors for HCl were generally higher for the southwestern fuels, particularly those found in the chaparral biome in the coastal regions of California.

  4. OXIDATION OF MERCURY ACROSS SCR CATALYSTS IN COAL-FIRED POWER PLANTS BURNING LOW RANK FUELS

    SciTech Connect

    Constance Senior

    2004-12-31

    The objectives of this program were to measure the oxidation of mercury in flue gas across SCR catalyst in a coal-fired power plant burning low rank fuels using a slipstream reactor containing multiple commercial catalysts in parallel and to develop a greater understanding of mercury oxidation across SCR catalysts in the form of a simple model. The Electric Power Research Institute (EPRI) and Argillon GmbH provided co-funding for this program. REI used a multicatalyst slipstream reactor to determine oxidation of mercury across five commercial SCR catalysts at a power plant that burned a blend of 87% subbituminous coal and 13% bituminous coal. The chlorine content of the blend was 100 to 240 {micro}g/g on a dry basis. Mercury measurements were carried out when the catalysts were relatively new, corresponding to about 300 hours of operation and again after 2,200 hours of operation. NO{sub x}, O{sub 2} and gaseous mercury speciation at the inlet and at the outlet of each catalyst chamber were measured. In general, the catalysts all appeared capable of achieving about 90% NO{sub x} reduction at a space velocity of 3,000 hr{sup -1} when new, which is typical of full-scale installations; after 2,200 hours exposure to flue gas, some of the catalysts appeared to lose NO{sub x} activity. For the fresh commercial catalysts, oxidation of mercury was in the range of 25% to 65% at typical full-scale space velocities. A blank monolith showed no oxidation of mercury under any conditions. All catalysts showed higher mercury oxidation without ammonia, consistent with full-scale measurements. After exposure to flue gas for 2,200 hours, some of the catalysts showed reduced levels of mercury oxidation relative to the initial levels of oxidation. A model of Hg oxidation across SCRs was formulated based on full-scale data. The model took into account the effects of temperature, space velocity, catalyst type and HCl concentration in the flue gas.

  5. An assessment of the benefits of the use of NASA developed fuel conservative technology in the US commercial aircraft fleet

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Cost and benefits of a fuel conservative aircraft technology program proposed by NASA are estimated. NASA defined six separate technology elements for the proposed program: (a) engine component improvement (b) composite structures (c) turboprops (d) laminar flow control (e) fuel conservative engine and (f) fuel conservative transport. There were two levels postulated: The baseline program was estimated to cost $490 million over 10 years with peak funding in 1980. The level two program was estimated to cost an additional $180 million also over 10 years. Discussions with NASA and with representatives of the major commercial airframe manufacturers were held to estimate the combinations of the technology elements most likely to be implemented, the potential fuel savings from each combination, and reasonable dates for incorporation of these new aircraft into the fleet.

  6. Electrochemical enhancement of nitric oxide removal from simulated lean-burn engine exhaust via solid oxide fuel cells.

    PubMed

    Huang, Ta-Jen; Wu, Chung-Ying; Lin, Yu-Hsien

    2011-07-01

    A solid oxide fuel cell (SOFC) unit is constructed with Ni-YSZ as the anode, YSZ as the electrolyte, and La(0.6)Sr(0.4)CoO(3)-Ce(0.9)Gd(0.1)O(1.95) as the cathode. The SOFC operation is performed at 600 °C with a cathode gas simulating the lean-burn engine exhaust and at various fixed voltage, at open-circuit voltage, and with an inert gas flowing over the anode side, respectively. Electrochemical enhancement of NO decomposition occurs when an operating voltage is generated; higher O(2) concentration leads to higher enhancement. Smaller NO concentration results in larger NO conversion. Higher operating voltage and higher O(2) concentration can lead to both higher NO conversion and lower fuel consumption. The molar rate of the consumption of the anode fuel can be very much smaller than that of NO to N(2) conversion. This makes the anode fuel consumed in the SOFC-DeNO(x) process to be much less than the equivalent amount of ammonia consumed in the urea-based selective catalytic reduction process. Additionally, the NO conversion increases with the addition of propylene and SO(2) into the cathode gas. These are beneficial for the application of the SOFC-DeNO(x) technology on treating diesel and other lean-burn engine exhausts.

  7. Very High Temperature Reactor (VHTR) Deep Burn Core and Fuel Analysis -- Complete Design Selection for the Pebble Bed Reactor

    SciTech Connect

    B. Boer; A. M. Ougouag

    2010-09-01

    The Deep-Burn (DB) concept focuses on the destruction of transuranic nuclides from used light water reactor fuel. These transuranic nuclides are incorporated into TRISO coated fuel particles and used in gas-cooled reactors with the aim of a fractional fuel burnup of 60 to 70% in fissions per initial metal atom (FIMA). This high performance is expected through the use of multiple recirculation passes of the fuel in pebble form without any physical or chemical changes between passes. In particular, the concept does not call for reprocessing of the fuel between passes. In principle, the DB pebble bed concept employs the same reactor designs as the presently envisioned low-enriched uranium core designs, such as the 400 MWth Pebble Bed Modular Reactor (PBMR-400). Although it has been shown in the previous Fiscal Year (2009) that a PuO2 fueled pebble bed reactor concept is viable, achieving a high fuel burnup, while remaining within safety-imposed prescribed operational limits for fuel temperature, power peaking and temperature reactivity feedback coefficients for the entire temperature range, is challenging. The presence of the isotopes 239-Pu, 240-Pu and 241-Pu that have resonances in the thermal energy range significantly modifies the neutron thermal energy spectrum as compared to a ”standard,” UO2-fueled core. Therefore, the DB pebble bed core exhibits a relatively hard neutron energy spectrum. However, regions within the pebble bed that are near the graphite reflectors experience a locally softer spectrum. This can lead to power and temperature peaking in these regions. Furthermore, a shift of the thermal energy spectrum with increasing temperature can lead to increased absorption in the resonances of the fissile Pu isotopes. This can lead to a positive temperature reactivity coefficient for the graphite moderator under certain operating conditions. The effort of this task in FY 2010 has focused on the optimization of the core to maximize the pebble discharge

  8. OXIDATION OF MERCURY ACROSS SCR CATALYSTS IN COAL-FIRED POWER PLANTS BURNING LOW RANK FUELS

    SciTech Connect

    Constance Senior; Temi Linjewile

    2003-07-25

    This is the first Quarterly Technical Report for DOE Cooperative Agreement No: DE-FC26-03NT41728. The objective of this program is to measure the oxidation of mercury in flue gas across SCR catalyst in a coal-fired power plant burning low rank fuels using a slipstream reactor containing multiple commercial catalysts in parallel. The Electric Power Research Institute (EPRI) and Ceramics GmbH are providing co-funding for this program. This program contains multiple tasks and good progress is being made on all fronts. During this quarter, analysis of the coal, ash and mercury speciation data from the first test series was completed. Good agreement was shown between different methods of measuring mercury in the flue gas: Ontario Hydro, semi-continuous emission monitor (SCEM) and coal composition. There was a loss of total mercury across the commercial catalysts, but not across the blank monolith. The blank monolith showed no oxidation. The data from the first test series show the same trend in mercury oxidation as a function of space velocity that has been seen elsewhere. At space velocities in the range of 6,000-7,000 hr{sup -1} the blank monolith did not show any mercury oxidation, with or without ammonia present. Two of the commercial catalysts clearly showed an effect of ammonia. Two other commercial catalysts showed an effect of ammonia, although the error bars for the no-ammonia case are large. A test plan was written for the second test series and is being reviewed.

  9. Indoor air pollution from burning yak dung as a household fuel in Tibet

    NASA Astrophysics Data System (ADS)

    Xiao, Qingyang; Saikawa, Eri; Yokelson, Robert J.; Chen, Pengfei; Li, Chaoliu; Kang, Shichang

    2015-02-01

    Yak dung is widely used for cooking and heating in Tibet. We measured real-time concentrations of black carbon (BC) and fine particulate matter with an aerodynamic diameter of 2.5 μm or less (PM2.5) emitted by yak dung burning in six households with different living conditions and stove types in the Nam Co region, Tibet. We observed a much lower average BC/PM2.5 mass ratio (0.013, range 0.006-0.028) from dung combustion in this area than previously reported estimates, ranging between 0.05 and 0.11. Based on our measurements, estimated fuel use, and published emission factors of BC and PM2.5, about 0.4-1.7 Gg/year of BC is emitted by yak dung combustion in Tibet in addition to the previously estimated 0.70 Gg/year of BC for Tibetan residential sources. Our survey shows that most residents were aware of adverse health impacts of indoor yak dung combustion and approximately 2/3 of residents had already installed chimney stoves to mitigate indoor air pollution. However, our measurements reveal that, without adequate ventilation, installing a chimney may not ensure good indoor air quality. For instance, the 6-h average BC and PM2.5 concentrations in a stone house using a chimney stove were 24.5 and 873 μg/m3, respectively. We also observed a change in the BC/PM2.5 ratios before and after a snow event. The impact of dung moisture content on combustion efficiency and pollutant emissions needs further investigation.

  10. Effect of water injection on nitric oxide emissions of a gas turbine combustor burning natural gas fuel

    NASA Technical Reports Server (NTRS)

    Marchionna, N. R.; Diehl, L. A.; Trout, A. M.

    1973-01-01

    The effect of direct water injection on the exhaust gas emissions of a turbojet combustor burning natural gas fuel was investigated. The results are compared with the results from similar tests using ASTM Jet-A fuel. Increasing water injection decreased the emissions of oxides of nitrogen (NOX) and increased the emissions of carbon monoxide and unburned hydrocarbons. The greatest percentage decrease in NOX with increasing water injection was at the lowest inlet-air temperature tested. The effect of increasing inlet-air temperature was to decrease the effect of the water injection. The reduction in NOX due to water injection was almost identical to the results obtained with Jet-A fuel. However, the emission indices of unburned hydrocarbons, carbon monoxide, and percentage nitric oxide in NOX were not.

  11. Densified refuse-derived fuel (d-RDF) burn at Marcy Psychiatric Center. Final report Mar 80-Nov 80

    SciTech Connect

    Galson, E.

    1980-11-01

    A densified refuse derived fuel (d-RDF) product was fired for approximately 50 hours as a supplemental fuel in a coal fired spreader stoker boiler at the Marcy Psychiatric Center in Marcy, New York. Observations were made and photographs were taken of plant operation during all phases of the test project. Opacity and particulate emission tests were performed while firing d-RDF in a ratio of 1:2 with coal (by volume) and while firing 100 percent coal at high and low loads to provide comparisons with State Department of Environmental Conservation emission standards. No significant disadvantages over coal were found in burning d-RDF/coal in ratios up to 2:1 (43 percent heat input by d-RDF). Fuel handling, boiler operation, boiler efficiency, particulate emissions and opacity were similar for the coal and d-RDF/coal mixtures.

  12. Nonlinear Burn Control in Tokamaks using Heating, Non-axisymmetric Magnetic Fields, Isotopic fueling and Impurity injection

    NASA Astrophysics Data System (ADS)

    Pajares, Andres; Schuster, Eugenio

    2016-10-01

    Plasma density and temperature regulation in future tokamaks such as ITER is arising as one of the main problems in nuclear-fusion control research. The problem, known as burn control, is to regulate the amount of fusion power produced by the burning plasma while avoiding thermal instabilities. Prior work in the area of burn control considered different actuators, such as modulation of the auxiliary power, modulation of the fueling rate, and controlled impurity injection. More recently, the in-vessel coil system was suggested as a feasible actuator since it has the capability of modifying the plasma confinement by generating non-axisymmetric magnetic fields. In this work, a comprehensive, model-based, nonlinear burn control strategy is proposed to integrate all the previously mentioned actuators. A model to take into account the influence of the in-vessel coils on the plasma confinement is proposed based on the plasma collisionality and the density. A simulation study is carried out to show the capability of the controller to drive the system between different operating points while rejecting perturbations. Supported by the US DOE under DE-SC0010661.

  13. Comparison of emissions and efficiency of a turbocharged lean-burn natural gas and Hythane-fueled engine

    SciTech Connect

    Larsen, J.F.; Wallace, J.S.

    1997-01-01

    An experiment was conducted to evaluate the potential for reduced exhaust emissions and improved efficiency, by way of lean-burn engine fueling with hydrogen supplemented natural gas (Hythane). The emissions and efficiency of the Hythane fuel (15% hydrogen, 85% natural gas by volume), were compared to the emissions and efficiency of pure natural gas using a turbocharged, spark ignition, 3.1 L, V-6 engine. The feasibility of heavy duty engine fueling with Hythane was assessed through testing conducted at engine speed and load combinations typical of heavy-duty engine operation. Comparison of the efficiency and emissions at MBT spark timing revealed that Hythane fueling of the test engine resulted in consistently lower brake specific energy consumption and emissions of total hydrocarbons (THC), carbon monoxide (CO), and carbon dioxide (CO{sub 2}), at a given equivalence ratio. There was no clear trend with respect to MBT oxides of nitrogen (NO{sub x}) emissions. It was also discovered that an improved NO{sub x}-THC tradeoff resulted when Hythane was used to fuel the test engine. Consequently, Hythane engine operating parameters can be adjusted to achieve a concurrent reduction in NO{sub x} and THC emissions relative to natural gas fueling.

  14. Fossil fuel and biomass burning effect on climate - Heating or cooling?

    NASA Technical Reports Server (NTRS)

    Kaufman, Yoram J.; Fraser, Robert S.; Mahoney, Robert L.

    1991-01-01

    The basic theory of the effect of pollution on cloud microphysics and its global implications is applied to compare the relative effect of a small increase in the consumption rate of oil, coal, or biomass burning on cooling and heating of the atmosphere. The characteristics of and evidence for the SO2 induced cooling effect are reviewed. This perturbation analysis approach permits linearization, therefore simplifying the analysis and reducing the number of uncertain parameters. For biomass burning the analysis is restricted to burning associated with deforestation. Predictions of the effect of an increase in oil or coal burning show that within the present conditions the cooling effect from oil and coal burning may range from 0.4 to 8 times the heating effect.

  15. Scheduled Civil Aircraft Emission Inventories for 1976 and 1984: Database Development and Analysis

    NASA Technical Reports Server (NTRS)

    Baughcum, Steven L.; Henderson, Stephen C.; Tritz, Terrance G.

    1996-01-01

    This report describes the development of a three-dimensional database of aircraft fuel burn and emissions (fuel burned, NOx, CO, and hydrocarbons) from scheduled commercial aircraft for four months (February, May, August, and November) of 1976 and 1984. Combining this data with earlier published data for 1990 and 1992, trend analyses for fuel burned, NOx, carbon monoxide, and hydrocarbons were calculated for selected regions (global, North America, Europe, North Atlantic, and North Pacific). These emissions inventories are available for use by atmospheric scientists conducting the Atmospheric Effects of Aviation Project (AEAP) modeling studies. Fuel burned and emissions of nitrogen oxides (NOx as NO2), carbon monoxide, and hydrocarbons have been calculated on a 1 degree latitude x 1 degree longitude x 1 kilometer altitude grid and delivered to NASA as electronic files.

  16. Unitized Regenerative Fuel Cells for solar rechargeable aircraft and zero emission vehicles

    NASA Astrophysics Data System (ADS)

    Mitlitsky, Fred; Colella, Nicholas J.; Myers, Blake

    1994-09-01

    A unitized regenerative fuel cell (URFC) produces power and electrolytically regenerates its reactants using a single stack of reversible cells. URFC'S have been designed for high altitude long endurance (HALE) solar rechargeable aircraft (SRA), zero emission vehicles (ZEV's), hybrid energy storage/propulsion systems for long duration satellites, energy storage for remote (off-grid) power sources, and peak shaving for on-grid applications. URFC's have been considered using hydrogen/oxygen, hydrogen/air, or hydrogen/halogen chemistries. This discussion is limited to the lightweight URFC energy storage system designs for span-loaded HALE SRA using hydrogen/oxygen, and for ZEV's using hydrogen/air with oxygen supercharging. Overlapping and synergistic development and testing opportunities for these two technologies will be highlighted.

  17. A Turbo-Brayton Cryocooler for Aircraft Superconducting Systems

    NASA Technical Reports Server (NTRS)

    Dietz, Anthony

    2014-01-01

    Hybrid turboelectric aircraft-with gas turbines driving electric generators connected to electric propulsion motors-have the potential to transform aircraft design. Decoupling power generation from propulsion enables innovative aircraft designs, such as blended-wing bodies, with distributed propulsion. These hybrid turboelectric aircraft have the potential to significantly reduce emissions, decrease fuel burn, and reduce noise, all of which are required to make air transportation growth projections sustainable. The power density requirements for these electric machines can only be achieved with superconductors, which in turn require lightweight, high-capacity cryocoolers.

  18. Chemical states of fission products in irradiated (U 0.3Pu 0.7)C 1+ x fuel at high burn-ups

    NASA Astrophysics Data System (ADS)

    Agarwal, Renu; Venugopal, V.

    2006-12-01

    The chemical states of fission products have been theoretically determined for the irradiated carbide fuel of Fast Breeder Test Reactor (FBTR) at Kalpakkam, India, at different burn-ups. The SOLGASMIX-PV computer code was used to determine the equilibrium chemical composition of the fuel. The system was assumed to be composed of a gaseous phase at one atmosphere pressure, and various solid phases. The distribution of elements in these phases and their chemical states at different temperatures were calculated as a function of burn-up. The FBTR fuel, (U 0.3Pu 0.7)C 1+ x, was loaded with C/M values in the range, 1.03-1.06. The present calculations indicated that even for the lowest starting C/M of 1.03 in the FBTR fuel, the liquid metal phase of (U, Pu), should not appear at a burn-up as high as 150 GWd/t.

  19. Indoor concentrations of nitrogen dioxide and sulfur dioxide from burning solid fuels for cooking and heating in Yunnan Province, China.

    PubMed

    Seow, W J; Downward, G S; Wei, H; Rothman, N; Reiss, B; Xu, J; Bassig, B A; Li, J; He, J; Hosgood, H D; Wu, G; Chapman, R S; Tian, L; Wei, F; Caporaso, N E; Vermeulen, R; Lan, Q

    2016-10-01

    The Chinese national pollution census has indicated that the domestic burning of solid fuels is an important contributor to nitrogen dioxide (NO2 ) and sulfur dioxide (SO2 ) emissions in China. To characterize indoor NO2 and SO2 air concentrations in relation to solid fuel use and stove ventilation in the rural counties of Xuanwei and Fuyuan, in Yunnan Province, China, which have among the highest lung cancer rates in the nation, a total of 163 participants in 30 selected villages were enrolled. Indoor 24-h NO2 and SO2 samples were collected in each household over two consecutive days. Compared to smoky coal, smokeless coal use was associated with higher NO2 concentrations [geometric mean (GM) = 132 μg/m(3) for smokeless coal and 111 μg/m(3) for smoky coal, P = 0.065] and SO2 [limit of detection = 24 μg/m(3) ; percentage detected (%Detect) = 86% for smokeless coal and 40% for smoky coal, P < 0.001]. Among smoky coal users, significant variation of NO2 and SO2 air concentrations was observed across different stove designs and smoky coal sources in both counties. Model construction indicated that the measurements of both pollutants were influenced by stove design. This exposure assessment study has identified high levels of NO2 and SO2 as a result of burning solid fuels for cooking and heating.

  20. Effects of Gas-Phase Radiation and Detailed Kinetics on the Burning and Extinction of a Solid Fuel

    NASA Technical Reports Server (NTRS)

    Rhatigan, Jennifer L.

    2001-01-01

    This is the first attempt to analyze both radiation and detailed kinetics on the burning and extinction of a solid fuel in a stagnation-point diffusion flame. We present a detailed and comparatively accurate computational model of a solid fuel flame along with a quantitative study of the kinetics mechanism, radiation interactions, and the extinction limits of the flame. A detailed kinetics model for the burning of solid trioxane (a trimer of formaldehyde) is coupled with a narrowband radiation model, with carbon dioxide, carbon monoxide, and water vapor as the gas-phase participating media. The solution of the solid trioxane diffusion flame over the flammable regime is presented in some detail, as this is the first solution of a heterogeneous trioxane flame. We identify high-temperature and low-temperature reaction paths for the heterogeneous trioxane flame. We then compare the adiabatic solution to solutions that include Surface radiation only and gas-phase and surface radiation using a black surface model. The analysis includes discussion of detailed flame chemistry over the flammable regime and, in particular, at the low stretch extinction limit. We emphasize the low stretch regime of the radiatively participating flame, since this is the region representative of microgravity flames. When only surface radiation is included, two extinction limits exist (the blow-off limit, and the low stretch radiative limit), and the burning rate and maximum flame temperatures are lower, as expected. With the inclusion of surface and gas-phase radiation, results show that, while flame temperatures are lower, the burning rate of the trioxane diffusion flame may actually increase at low stretch rate due to radiative feedback from the flame to the surface.

  1. Fuel consumption and fire emissions estimates using Fire Radiative Power, burned area and statistical modelling on the fire event scale

    NASA Astrophysics Data System (ADS)

    Ruecker, Gernot; Leimbach, David; Guenther, Felix; Barradas, Carol; Hoffmann, Anja

    2016-04-01

    Fire Radiative Power (FRP) retrieved by infrared sensors, such as flown on several polar orbiting and geostationary satellites, has been shown to be proportional to fuel consumption rates in vegetation fires, and hence the total radiative energy released by a fire (Fire Radiative Energy, FRE) is proportional to the total amount of biomass burned. However, due to the sparse temporal coverage of polar orbiting and the coarse spatial resolution of geostationary sensors, it is difficult to estimate fuel consumption for single fire events. Here we explore an approach for estimating FRE through temporal integration of MODIS FRP retrievals over MODIS-derived burned areas. Temporal integration is aided by statistical modelling to estimate missing observations using a generalized additive model (GAM) and taking advantage of additional information such as land cover and a global dataset of the Canadian Fire Weather Index (FWI), as well as diurnal and annual FRP fluctuation patterns. Based on results from study areas located in savannah regions of Southern and Eastern Africa and Brazil, we compare this method to estimates based on simple temporal integration of FRP retrievals over the fire lifetime, and estimate the potential variability of FRP integration results across a range of fire sizes. We compare FRE-based fuel consumption against a database of field experiments in similar landscapes. Results show that for larger fires, this method yields realistic estimates and is more robust when only a small number of observations is available than the simple temporal integration. Finally, we offer an outlook on the integration of data from other satellites, specifically FireBird, S-NPP VIIRS and Sentinel-3, as well as on using higher resolution burned area data sets derived from Landsat and similar sensors.

  2. Fuel dispersal in high-speed aircraft/soil impact scenarios

    SciTech Connect

    Tieszen, S.R.; Attaway, S.W.

    1996-01-01

    The objective of this study is to determine how the jet fuel contained in aircraft wing tanks disperses on impact with a soft terrain, i.e., soils, at high impact velocities. The approach used in this study is to combine experimental and numerical methods. Tests were conducted with an approximately 1/42 linear-scale mass-model of a 1/4 span section of a C-141 wing impacting a sand/clay mixture. The test results showed that within the uncertainty of the data, the percentage of incident liquid mass remaining in the crater is the same as that qualitatively described in earlier napalm bomb development studies. Namely, the percentage of fuel in the crater ranges from near zero for grazing impacts to 25%--50% for high angles of impact. To support a weapons system safety assessment (WSSA), the data from the current study have been reduced to correlations. The numerical model used in the current study is a unique coupling of a Smooth Particle Hydrodynamics (SPH) method with the transient dynamics finite element code PRONTO. Qualitatively, the splash, erosion, and soil compression phenomena are all numerically predicted. Quantitatively, the numerical method predicted a smaller crater cross section than was observed in the tests.

  3. Aircraft Emission Scenarios Projected in Year 2015 for the NASA Technology Concept Aircraft (TCA) High Speed Civil Transport

    NASA Technical Reports Server (NTRS)

    Baughcum, Steven L.; Henderson, Stephen C.

    1998-01-01

    This report describes the development of a three-dimensional database of aircraft fuel burn and emissions (fuel burned, NOx, CO, and hydrocarbons) from projected fleets of high speed civil transports (HSCTs) on a universal airline network. Inventories for 500 and 1000 HSCT fleets, as well as the concurrent subsonic fleets, were calculated. The HSCT scenarios are calculated using the NASA technology concept airplane (TCA) and update an earlier report. These emissions inventories are available for use by atmospheric scientists conducting the Atmospheric Effects of Stratospheric Aircraft (AESA) modeling studies. Fuel burned and emissions of nitrogen oxides (NOx as NO2), carbon monoxide, and hydrocarbons have been calculated on a 1 degree latitude x 1 degree longitude x 1 kilometer pressure altitude grid and delivered to NASA as electronic files.

  4. Testing a basic assumption of shrubland fire management: Does the hazard of burning increase with the age of fuels?

    USGS Publications Warehouse

    Moritz, Max A.; Keeley, Jon E.; Johnson, Edward A.; Schaffner, Andrew A.

    2004-01-01

    This year's catastrophic wildfires in southern California highlight the need for effective planning and management for fire-prone landscapes. Fire frequency analysis of several hundred wildfires over a broad expanse of California shrublands reveals that there is generally not, as is commonly assumed, a strong relationship between fuel age and fire probabilities. Instead, the hazard of burning in most locations increases only moderately with time since the last fire, and a marked age effect of fuels is observed only in limited areas. Results indicate a serious need for a re-evaluation of current fire management and policy, which is based largely on eliminating older stands of shrubland vegetation. In many shrubland ecosystems exposed to extreme fire weather, large and intense wildfires may need to be factored in as inevitable events.

  5. Global Partitioning of NOx Sources Using Satellite Observations: Relative Roles of Fossil Fuel Combustion, Biomass Burning and Soil Emissions

    NASA Technical Reports Server (NTRS)

    Jaegle, Lyatt; Steinberger, Linda; Martin, Randall V.; Chance, Kelly

    2005-01-01

    This document contains the following abstract for the paper "Global partitioning of NOx sources using satellite observations: Relative roles of fossil fuel combustion, biomass burning and soil emissions." Satellite observations have been used to provide important new information about emissions of nitrogen oxides. Nitrogen oxides (NOx) are significant in atmospheric chemistry, having a role in ozone air pollution, acid deposition and climate change. We know that human activities have led to a three- to six-fold increase in NOx emissions since pre-industrial times, and that there are three main surface sources of NOx: fuel combustion, large-scale fires, and microbial soil processes. How each of these sources contributes to the total NOx emissions is subject to some doubt, however. The problem is that current NOx emission inventories rely on bottom-up approaches, compiling large quantities of statistical information from diverse sources such as fuel and land use, agricultural data, and estimates of burned areas. This results in inherently large uncertainties. To overcome this, Lyatt Jaegle and colleagues from the University of Washington, USA, used new satellite observations from the Global Ozone Monitoring Experiment (GOME) instrument. As the spatial and seasonal distribution of each of the sources of NOx can be clearly mapped from space, the team could provide independent topdown constraints on the individual strengths of NOx sources, and thus help resolve discrepancies in existing inventories. Jaegle's analysis of the satellite observations, presented at the recent Faraday Discussion on "Atmospheric Chemistry", shows that fuel combustion dominates emissions at northern mid-latitudes, while fires are a significant source in the Tropics. Additionally, she discovered a larger than expected role for soil emissions, especially over agricultural regions with heavy fertilizer use. Additional information is included in the original extended abstract.

  6. Burning Rate Emulator

    NASA Video Gallery

    The Burning Rate Emulator is a gas fuel investigation attempting to emulate the burning of solids to improve our understanding of materials''flammability over a wide range of conditions. The approa...

  7. Drying, burning and emission characteristics of beehive charcoal briquettes: an alternative household fuel of Eastern Himalayan Region.

    PubMed

    Mandal, S; Kumar, Arvind; Singh, R K; Kundu, K

    2014-05-01

    Beehive charcoal briquettes were produced from powdered charcoal in which soil was added as binder. It was found to be an eco-friendly, clean and economic alternative source of household fuel for the people of Eastern Himalayan Region. Experiments were conducted to determine natural drying behaviour, normalised burn rate, temperature profile and emission of CO, CO2, UBHC (unburnt hydrocarbons) and NO(x) of beehive briquettes prepared from 60:40; 50:50 and 40:60 ratios of charcoal and soil. It was observed that under natural drying conditions (temperature, humidity) briquettes took 433 hr to reach equilibrium moisture content of 5.56-10.29%. Page's model was found suitable to describe the drying characteristics of all three combinations. Normalised burn rate varied between 0.377-0.706% of initial mass min⁻¹. Total burning time of briquette ranged between 133-143 min. The peak temperature attained by briquettes ranged from 437 °C to 572 °C. All the briquette combinations were found suitable for cooking and space heating. Emission of CO, CO2, UBHC, NO and NO2 ranged between 68.4-107.2, 922-1359, 20.9-50.8, 0.19-0.29 and 0.34-0.64 g kg⁻¹, respectively which were less than firewood.

  8. Instant release fraction and matrix release of high burn-up UO2 spent nuclear fuel: Effect of high burn-up structure and leaching solution composition

    NASA Astrophysics Data System (ADS)

    Serrano-Purroy, D.; Clarens, F.; González-Robles, E.; Glatz, J. P.; Wegen, D. H.; de Pablo, J.; Casas, I.; Giménez, J.; Martínez-Esparza, A.

    2012-08-01

    Two weak points in Performance Assessment (PA) exercises regarding the alteration of Spent Nuclear Fuel (SNF) are the contribution of the so-called Instant Release Fraction (IRF) and the effect of High Burn-Up Structure (HBS). This manuscript focuses on the effect of HBS in matrix (long term) and instant release of a Pressurised Water Reactor (PWR) SNF irradiated in a commercial reactor with a mean Burn-Up (BU) of 60 GWd/tU. In order to study the HBS contribution, two samples from different radial positions have been prepared. One from the centre of the SNF, labelled CORE, and one from the periphery, enriched with HBS and labelled OUT. Static leaching experiments have been carried out with two synthetic leaching solutions: bicarbonate (BIC) and Bentonitic Granitic Groundwater (BGW), and in all cases under oxidising conditions. IRF values have been calculated from the determined Fraction of Inventory in Aqueous Phase (FIAP). In all studied cases, some radionuclides (RN): Rb, Sr and Cs, have shown higher release rates than uranium, especially at the beginning of the experiment, and have been considered as IRF. Redox sensitive RN like Mo and Tc have been found to dissolve slightly faster than uranium and further studies might be needed to confirm if they can also be considered part of the IRF. Most of the remaining studied RN, mainly actinides and lanthanides, have been found to dissolve congruently with the uranium matrix. Finally, Zr, Ru and Rh presented lower release rates than the matrix. Higher matrix release has been determined for CORE than for OUT samples showing that the formation of HBS might have a protective effect against the oxidative corrosion of the SNF. On the contrary, no significant differences have been observed between the two studied leaching solutions (BIC and BGW). Two different IRF contributions have been determined. One corresponding to the fraction of inventory segregated in the external open grain boundaries, directly available to water and

  9. On the condition of UO2 nuclear fuel irradiated in a PWR to a burn-up in excess of 110 MWd/kgHM

    NASA Astrophysics Data System (ADS)

    Restani, R.; Horvath, M.; Goll, W.; Bertsch, J.; Gavillet, D.; Hermann, A.; Martin, M.; Walker, C. T.

    2016-12-01

    Post-irradiation examination results are presented for UO2 fuel from a PWR fuel rod that had been irradiated to an average burn-up of 105 MWd/kgHM and showed high fission gas release of 42%. The radial distribution of xenon and the partitioning of fission gas between bubbles and the fuel matrix was investigated using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and electron probe microanalysis. It is concluded that release from the fuel at intermediate radial positions was mainly responsible for the high fission gas release. In this region thermal release had occurred from the high burn-up structure (HBS) at some point after the sixth irradiation cycle. The LA-ICP-MS results indicate that gas release had also occurred from the HBS in the vicinity of the pellet periphery. It is shown that the gas pressure in the HBS pores is well below the pressure that the fuel can sustain.

  10. New perspectives on quantitative characterization of biomass burning (Invited)

    NASA Astrophysics Data System (ADS)

    Ichoku, C. M.

    2010-12-01

    Biomass burning (BB) occurs seasonally in different vegetated landscapes across the world, consuming large amounts of biomass, generating intense heat energy, and emitting corresponding amounts of smoke plumes that comprise aerosols and trace gases, which include carbon monoxide (CO), carbon dioxide (CO2), methane (CH4), non-methane hydrocarbons, and numerous other trace compounds, many of which have adverse effects on human health, air quality, and environmental processes. Accurate estimates of these emissions are required as model inputs to evaluate and forecast smoke plume transport and impacts on air quality, human health, clouds, weather, radiation, and climate. The goal of this presentation is to highlight results of research activities that are aimed at advancing the quantitative characterization of various aspects of biomass burning (energetics, intensity, burn areas, burn severity, emissions, and fire weather) from aircraft and satellite measurements that can help advance our understanding of biomass burning and its overall effects. We will show recent results of analysis of fire radiative power (FRP), burned areas, fuel consumption, smoke emission rates, and plume heights from satellite measurements, as well as related aircraft calibration/validation activities. We will also briefly examine potential future plans and strategies for effective monitoring of biomass burning characteristics and emissions from aircraft and satellite.

  11. [Burns in an aeronautic environment].

    PubMed

    Rigotti, G

    1979-10-27

    Following an examination of the aetiology of burns in aeronautic environments, the physiopathology, classification and general and local treatment of the burn case is discussed. Special mention is then made of aircraft as an extremely useful means of transport.

  12. Combustion tests of a turbine simulator burning low Btu fuel from a fixed bed gasifier

    SciTech Connect

    Cook, C.S.; Abuaf, N.; Feitelberg, A.S.; Hung, S.L.; Najewicz, D.J.; Samuels, M.S.

    1993-11-01

    One of the most efficient and environmentally compatible coal fueled power generation technologies is the integrated gasification combined cycle (IGCC) concept. Commercialization of the IGCC/HGCU concept requires successful development of combustion systems for high temperature low Btu fuel in gas turbines. Toward this goal, a turbine combustion system simulator has been designed, constructed, and fired with high temperature low Btu fuel. Fuel is supplied by a pilot scale fixed bed gasifier and hot gas desulfurization system. The primary objectives of this project are: (1) demonstration of long term operability of the turbine simulator with high temperature low Btu fuel; (2) measurement of NO{sub x}, CO, and particulate emissions; and (3) characterization of particulates in the fuel as well as deposits in the fuel nozzle, combustor, and first stage nozzle. In a related project, a reduced scale rich-quench-lean (RQL) gas turbine combustor has been designed, constructed, and fired with simulated low Btu fuel. The overall objective of this project is to develop an RQL combustor with lower conversion of fuel bound nitrogen (FBN) to NO{sub x} than a conventional combustor.

  13. Global partitioning of NOx sources using satellite observations: relative roles of fossil fuel combustion, biomass burning and soil emissions.

    PubMed

    Jaeglé, Lyatt; Steinberger, Linda; Martin, Randall V; Chance, Kelly

    2005-01-01

    We use space-based observations of NO2 columns from the Global Ozone Monitoring Experiment (GOME) to derive monthly top-down NOx emissions for 2000 via inverse modeling with the GEOS-CHEM chemical transport model. Top-down NOx sources are partitioned among fuel combustion (fossil fuel and biofuel), biomass burning and soils by exploiting the spatio-temporal distribution of remotely sensed fires and a priori information on the location of regions dominated by fuel combustion. The top-down inventory is combined with an a priori inventory to obtain an optimized a posteriori estimate of the relative roles of NOx sources. The resulting a posteriori fuel combustion inventory (25.6 TgN year(-1)) agrees closely with the a priori (25.4 TgN year(-1)), and errors are reduced by a factor of 2, from +/- 80% to +/- 40%. Regionally, the largest differences are found over Japan and South Africa, where a posteriori estimates are 25% larger than a priori. A posteriori fuel combustion emissions are aseasonal, with the exception of East Asia and Europe where winter emissions are 30-40% larger relative to summer emissions, consistent with increased energy use during winter for heating. Global a posteriori biomass burning emissions in 2000 resulted in 5.8 TgN (compared to 5.9 TgN year(-1) in the a priori), with Africa accounting for half of this total. A posteriori biomass burning emissions over Southeast Asia/India are decreased by 46% relative to a priori; but over North equatorial Africa they are increased by 50%. A posteriori estimates of soil emissions (8.9 TgN year(-1)) are 68% larger than a priori (5.3 TgN year(-1)). The a posteriori inventory displays the largest soil emissions over tropical savanna/woodland ecosystems (Africa), as well as over agricultural regions in the western U.S. (Great Plains), southern Europe (Spain, Greece, Turkey), and Asia (North China Plain and North India), consistent with field measurements. Emissions over these regions are highest during summer at

  14. Impact Response Study on Covering Cap of Aircraft Big-Size Integral Fuel Tank

    NASA Astrophysics Data System (ADS)

    Wang, Fusheng; Jia, Senqing; Wang, Yi; Yue, Zhufeng

    2016-10-01

    In order to assess various design concepts and choose a kind of covering cap design scheme which can meet the requirements of airworthiness standard and ensure the safety of fuel tank. Using finite element software ANSYS/LS- DYNA, the impact process of covering cap of aircraft fuel tank by projectile were simulated, in which dynamical characteristics of simple single covering cap and gland double-layer covering cap impacted by titanium alloy projectile and rubber projectile were studied, as well as factor effects on simple single covering cap and gland double-layer covering cap under impact region, impact angle and impact energy were also studied. Though the comparison of critical damage velocity and element deleted number of the covering caps, it shows that the external covering cap has a good protection effect on internal covering cap. The regions close to boundary are vulnerable to appear impact damage with titanium alloy projectile while the regions close to center is vulnerable to occur damage with rubber projectile. Equivalent strain in covering cap is very little when impact angle is less than 15°. Element deleted number in covering cap reaches the maximum when impact angle is between 60°and 65°by titanium alloy projectile. While the bigger the impact angle and the more serious damage of the covering cap will be when rubber projectile impact composite covering cap. The energy needed for occurring damage on external covering cap and internal covering cap is less than and higher than that when single covering cap occur damage, respectively. The energy needed for complete breakdown of double-layer covering cap is much higher than that of single covering cap.

  15. SPECIATION OF GAS-PHASE AND FINE PARTICLE EMISSIONS FROM BURNING OF FOLIAR FUELS

    EPA Science Inventory

    Particle size distributions (10-1000 nm aerodynamic diameter), physical and chemical properties of fine particle matter (PM2.5) with aerodynamic diameter <2.5 micrometers, and gas-phase emissions from controlled open burning of assorted taxa were measured. Chemical speciation of ...

  16. Study of ignition, combustion, and production of harmful substances upon burning solid organic fuel at a test bench with a vortex chamber

    NASA Astrophysics Data System (ADS)

    Burdukov, A. P.; Chernetskiy, M. Yu.; Dekterev, A. A.; Anufriev, I. S.; Strizhak, P. A.; Greben'kov, P. Yu.

    2016-01-01

    Results of investigation of furnace processes upon burning of pulverized fuel at a test bench with a power of 5 MW are presented. The test bench consists of two stages with tangential air and pulverized coal feed, and it is equipped by a vibrocentrifugal mill and a disintegrator. Such milling devices have an intensive mechanical impact on solid organic fuel, which, in a number of cases, increases the reactivity of ground material. The processes of ignition and stable combustion of a mixture of gas coal and sludge (wastes of concentration plant), as well as Ekibastus coal, ground in the disintegrator, were studied at the test bench. The results of experimental burning demonstrated that preliminary fuel grinding in the disintegrator provides autothermal combustion mode even for hardly inflammable organic fuels. Experimental combustion of biomass, wheat straw with different lignin content (18, 30, 60%) after grinding in the disintegrator, was performed at the test bench in order to determine the possibility of supporting stable autothermal burning. Stable biofuel combustion mode without lighting by highly reactive fuel was achieved in the experiments. The influence of the additive GTS-Powder (L.O.M. Leaders Co., Ltd., Republic of Korea) in the solid and liquid state on reducing sulfur oxide production upon burning Mugun coal was studied. The results of experimental combustion testify that, for an additive concentration from 1 to 15% of the total mass of the burned mixture, the maximum SO2 concentration reduction in ejected gases was not more than 18% with respect to the amount for the case of burning pure coal.

  17. Characterization of carbonaceous aerosols outflow from India and Arabia: Biomass/biofuel burning and fossil fuel combustion

    NASA Astrophysics Data System (ADS)

    Guazzotti, S. A.; Suess, D. T.; Coffee, K. R.; Quinn, P. K.; Bates, T. S.; Wisthaler, A.; Hansel, A.; Ball, W. P.; Dickerson, R. R.; Neusüß, C.; Crutzen, P. J.; Prather, K. A.

    2003-08-01

    A major objective of the Indian Ocean Experiment (INDOEX) involves the characterization of the extent and chemical composition of pollution outflow from the Indian Subcontinent during the winter monsoon. During this season, low-level flow from the continent transports pollutants over the Indian Ocean toward the Intertropical Convergence Zone (ITCZ). Traditional standardized aerosol particle chemical analysis, together with real-time single particle and fast-response gas-phase measurements provided characterization of the sampled aerosol chemical properties. The gas- and particle-phase chemical compositions of encountered air parcels changed according to their geographic origin, which was traced by back trajectory analysis. The temporal evolutions of acetonitrile, a long-lived specific tracer for biomass/biofuel burning, number concentration of submicrometer carbon-containing particles with potassium (indicative of combustion sources), and mass concentration of submicrometer non-sea-salt (nss) potassium are compared. High correlation coefficients (0.84 < r2 < 0.92) are determined for these comparisons indicating that most likely the majority of the species evolve from the same, related, or proximate sources. Aerosol and trace gas measurements provide evidence that emissions from fossil fuel and biomass/biofuel burning are subject to long-range transport, thereby contributing to anthropogenic pollution even in areas downwind of South Asia. Specifically, high concentrations of submicrometer nss potassium, carbon-containing particles with potassium, and acetonitrile are observed in air masses advected from the Indian subcontinent, indicating a strong impact of biomass/biofuel burning in India during the sampling periods (74 (±9)% biomass/biofuel contribution to submicrometer carbonaceous aerosol). In contrast, lower values for these same species were measured in air masses from the Arabian Peninsula, where dominance of fossil fuel combustion is suggested by results

  18. Aircraft measurements of ozone, NOx, CO, and aerosol concentrations in biomass burning smoke over Indonesia and Australia in October 1997: Depleted ozone layer at low altitude over Indonesia

    NASA Astrophysics Data System (ADS)

    Tsutsumi, Yukitomo; Sawa, Yousuke; Makino, Yukio; Jensen, Jørgen B.; Gras, John L.; Ryan, Brian F.; Diharto, Sri; Harjanto, Hery

    The 1997 El Niño unfolded as one of the most sever El Niño Southern Oscillation (ENSO) events in this century and it coincided with massive biomass burning in the equatorial western Pacific region. To assess the influence on the atmosphere, aircraft observations of trace gases and aerosol were conducted over Kalimantan in Indonesia and Australia. Over Kalimantan in Indonesia, high concentrations of O3, NOx, CO, and aerosols were observed during the flight. Although the aerosol and NOx decreased with altitude, the O3 had the maximum concentration (80.5 ppbv) in the middle layer of the smoke haze and recorded very low concentrations (˜20 ppbv) in the lower smoke layer. This feature was not observed in the Australian smoke. We proposed several hypotheses for the low O3 concentration at low levels over Kalimantan. The most likely are lack of solar radiation and losses at the surface of aerosol particles.

  19. The effect of water injection on nitric oxide emissions of a gas turbine combustor burning ASTM Jet-A fuel

    NASA Technical Reports Server (NTRS)

    Marchionna, N. R.; Diehl, L. A.; Trout, A. M.

    1973-01-01

    Tests were conducted to determine the effect of water injection on oxides of nitrogen (NOx) emissions of a full annular, ram induction gas turbine combustor burning ASTM Jet-A fuel. The combustor was operated at conditions simulating sea-level takeoff and cruise conditions. Water at ambient temperature was injected into the combustor primary zone at water-fuel ratios up to 2. At an inlet-air temperature of 589 K (600 F) water injection decreased the NOx emission index at a constant exponential rate: NOx = NOx (o) e to the -15 W/F power (where W/F is the water-fuel ratio and NOx(o) indicates the value with no injection). The effect of increasing combustor inlet-air temperature was to decrease the effect of the water injection. Other operating variables such as pressure and reference Mach number did not appear to significantly affect the percent reduction in NOx. Smoke emissions were found to decrease with increasing water injection.

  20. NASA Lewis Research Center lean-, rich-burn materials test burner rig

    NASA Technical Reports Server (NTRS)

    Stearns, C. A.; Robinson, R. C.

    1994-01-01

    The lean-, rich-burn materials test burner rig at NASA LeRC is used to evaluate the high temperature environmental durability of aerospace materials. The rig burns jet fuel and pressurized air, and sample materials can be subjected to both lean-burn and rich-burn environments. As part of NASA's Enabling Propulsion Materials (EPM) program, an existing rig was adapted to simulate the rich-burn quick-quench lean-burn (RQL) combustor concept which is being considered for the HSCT (high speed civil transport) aircraft. RQL materials requirements exceed that of current superalloys, thus ceramic matrix composites (CMC's) emerged as the leading candidate materials. The performance of these materials in the quasi reducing environment of the rich-burn section of the RQL is of fundamental importance to materials development. This rig was developed to conduct such studies, and its operation and capabilities are described.

  1. Process for clean-burning fuel from low-rank coal

    DOEpatents

    Merriam, Norman W.; Sethi, Vijay; Brecher, Lee E.

    1994-01-01

    A process for upgrading and stabilizing low-rank coal involving the sequential processing of the coal through three fluidized beds; first a dryer, then a pyrolyzer, and finally a cooler. The fluidizing gas for the cooler is the exit gas from the pyrolyzer with the addition of water for cooling. Overhead gas from pyrolyzing is likely burned to furnish the energy for the process. The product coal exits with a tar-like pitch sealant to enhance its safety during storage.

  2. Some problems of burning low-grade fuels at heating and power plants

    SciTech Connect

    Dakhov, A.I.; Mikhailovskii, Yu.M.

    1983-03-01

    The combustion of low-grade coal in the heat and power plants in the USSR is discussed. The use of these coals in the power industry has increased while their quality has steadily decreased, especially during the last 2-3 five-year plans. This is especially true for coals produced by open pit mining. Suggestions are given to increase the efficiency of power plant boilers burning low-grade coals.

  3. Laminar burning velocities at high pressure for primary reference fuels and gasoline: Experimental and numerical investigation

    SciTech Connect

    Jerzembeck, S.; Peters, N.; Pepiot-Desjardins, P.; Pitsch, H.

    2009-02-15

    Spherical flames of n-heptane, iso-octane, PRF 87 and gasoline/air mixtures are experimentally investigated to determine laminar burning velocities and Markstein lengths under engine-relevant conditions by using the constant volume bomb method. Data are obtained for an initial temperature of 373 K, equivalence ratios varying from {phi}=0.7 to {phi}=1.2, and initial pressures from 10 to 25 bar. To track the flame front in the vessel a dark field He-Ne laser Schlieren measurement technique and digital image processing were used. The propagating speed with respect to the burned gases and the stretch rate are determined from the rate of change of the flame radius. The laminar burning velocities are obtained through a linear extrapolation to zero stretch. The experimentally determined Markstein numbers are compared to theoretical predictions. A reduced chemical kinetic mechanism for n-heptane and iso-octane was derived from the Lawrence Livermore comprehensive mechanisms. This mechanism was validated for ignition delay times and flame propagation at low and high pressures. In summary an overall good agreement with the various experimental data sets used in the validation was obtained. (author)

  4. Emissions of carbon monoxide and carbon dioxide from uncompressed and pelletized biomass fuel burning in typical household stoves in China

    NASA Astrophysics Data System (ADS)

    Wei, Wen; Zhang, Wei; Hu, Dan; Ou, Langbo; Tong, Yindong; Shen, Guofeng; Shen, Huizhong; Wang, Xuejun

    2012-09-01

    Carbon dioxide (CO2) and carbon monoxide (CO) impact climate change and human health. The uncertainties in emissions inventories of CO2 and CO are primarily due to the large variation in measured emissions factors (EFs), especially to the lack of EFs from developing countries. China's goals of reducing CO2 emissions require a maximum utilization of biomass fuels. Pelletized biomass fuels are well suited for the residential biomass market, providing possibilities of more automated and optimized systems with higher modified combustion efficiency (MCE) and less products from incomplete combustion. However, EFs of CO2 and CO from pellet biomass fuels are seldom reported, and a comparison to conventional uncompressed biomass fuels has never been conducted. Therefore, the objectives of this study were to experimentally determine the CO2 and CO EFs from uncompressed biomass (i.e., firewood and crop residues) and biomass pellets (i.e., pine wood pellet and corn straw pellet) under real residential applications and to compare the influences of fuel properties and combustion conditions on CO2 and CO emissions from the two types of biomass fuels. For the uncompressed biomass examples, the CO2 and CO EFs were 1649.4 ± 35.2 g kg-1 and 47.8 ± 8.9 g kg-1, respectively, for firewood and 1503.2 ± 148.5 g kg-1 and 52.0 ± 14.2 g kg-1, respectively, for crop residues. For the pellet biomass fuel examples, the CO2 and CO EFs were 1708.0 ± 3.8 g kg-1 and 4.4 ± 2.4 g kg-1, respectively, for pellet pine and 1552.1 ± 16.3 g kg-1 and 17.9 ± 10.2 g kg-1, respectively, for pellet corn. In rural China areas during 2007, firewood and crop residue burning produced 721.7 and 23.4 million tons of CO2 and CO, respectively.

  5. Determination of wood burning and fossil fuel contribution of black carbon at Delhi, India using aerosol light absorption technique.

    PubMed

    Tiwari, S; Pipal, A S; Srivastava, A K; Bisht, D S; Pandithurai, G

    2015-02-01

    A comprehensive measurement program of effective black carbon (eBC), fine particle (PM2.5), and carbon monoxide (CO) was undertaken during 1 December 2011 to 31 March 2012 (winter period) in Delhi, India. The mean mass concentrations of eBC, PM2.5, and CO were recorded as 12.1 ± 8.7 μg/m(3), 182.75 ± 114.5 μg/m(3), and 3.41 ± 1.6 ppm, respectively, during the study period. Also, the absorption Angstrom exponent (AAE) was estimated from eBC and varied from 0.38 to 1.29 with a mean value of 1.09 ± 0.11. The frequency of occurrence of AAE was ~17 % less than unity whereas ~83 % greater than unity was observed during the winter period in Delhi. The mass concentrations of eBC were found to be higher by ~34 % of the average value of eBC (12.1 μg/m(3)) during the study period. Sources of eBC were estimated, and they were ~94 % from fossil fuel (eBCff) combustion whereas only 6 % was from wood burning (eBCwb). The ratio between eBCff and eBCwb was 15, which indicates a higher impact from fossil fuels compared to biomass burning. When comparing eBCff during day and night, a factor of three higher concentrations was observed in nighttime than daytime, and it is due to combustion of fossil fuel (diesel vehicle emission) and shallow boundary layer conditions. The contribution of eBCwb in eBC was higher between 1800 and 2100 hours due to burning of wood/biomass. A significant correlation between eBC and PM2.5 (r = 0.78) and eBC and CO (r = 0.46) indicates the similarity in location sources. The mass concentration of eBC was highest (23.4 μg/m(3)) during the month of December when the mean visibility (VIS) was lowest (1.31 km). Regression analysis among wind speed (WS), VIS, soot particles, and CO was studied, and significant negative relationships were seen between VIS and eBC (-0.65), eBCff (-0.66), eBCwb (-0.34), and CO (-0.65); however, between WS and eBC (-0.68), eBCff (-0.67), eBCwb (-0.28), and CO (-0.53). The regression analysis indicated

  6. Deep Burn: Development of Transuranic Fuel for High-Temperature Helium-Cooled Reactors- Monthly Highlights November 2010

    SciTech Connect

    Snead, Lance Lewis; Bell, Gary L; Besmann, Theodore M

    2010-12-01

    During FY 2011 the DB Program will report Highlights on a monthly basis, but will no longer produce Quarterly Progress Reports. Technical details that were previously included in the quarterly reports will be included in the appropriate Milestone Reports that are submitted to FCRD Program Management. These reports will also be uploaded to the Deep Burn website. The Monthly Highlights report for October 2010, ORNL/TM-2010/300, was distributed to program participants on November 29, 2010. This report discusses the following: (1) Thermochemical Data and Model Development; (2) TRU (transuranic elements) TRISO (tri-structural isotropic) Development - (a) TRU Kernel Development, (b) Coating Development; (3) LWR Fully Ceramic Fuel - (a) FCM Fabrication Development, (b) FCM Irradiation Testing.

  7. Laboratory measurements of trace gas emissions from biomass burning of fuel types from the southeastern and southwestern United States

    SciTech Connect

    Burling, Ian; Yokelson, Robert J.; Griffith, David WT; Johnson, Timothy J.; Veres, Patrick; Roberts, J.; Warneke, Carsten; Urbanski, Shawn; Reardon, James; Weise, David; Hao, WeiMin; Gouw, Joost de

    2010-11-25

    Fuels commonly managed by prescribed burning were collected from five Department of Defense (DoD) bases in the southeast and southwest U.S. and burned under controlled conditions at the USFS Firelab in Missoula, MT. The smoke emissions were measured with a large suite of state-of-the-art instrumentation. A key instrument used in the measurement of the gas-phase species in smoke was an open-path Fourier transform infrared (OP FTIR) spectrometer. The OP FTIR detected and quantified 19 gas-phase species in these fires - CO2, CO, H2O, NO2, NO, HONO, NH3, HCl, SO2, CH4, CH3OH, HCHO, HCOOH, C2H2, C2H4, CH3COOH, HCN, C3H6 and C4H4O. Of particular interest, gas-phase nitrous acid (HONO) was detected in the smoke from all fires. The HONO emission factor ranged from 0.15 to 0.60 g kg 1 and was higher for the southeast fuels. Similarly, the fire-integrated molar emission ratios (relative to NOx) ranged from approximately 0.03 to 0.20, with higher values observed for the southeast fuels. HONO is an important precursor in the production of OH, the primary oxidizing species in the atmosphere but there exists little previous data documenting HONO emissions from either wild or prescribed fires. The detected non-methane organic compound (NMOC) emissions were dominated by oxygenated volatile organic compounds (OVOCs) with total identified molar OVOC emissions ranging from 39 to 79% of the total identified molar non-methane organic compounds (NMOC). Emitted NMOC can undergo further oxidation and photolysis in the case of OVOC and thus involved in secondary aerosol formation. Elevated amounts of gas-phase HCl and SO2 were also detected in the smoke, with the amounts varying depending on location and vegetation type. Emission factors for HCl were typically much higher for the southwest fuels, particularly those found in the chaparral biome in the coastal regions of California.

  8. CO{sub 2}-mitigation measures through reduction of fossil fuel burning in power utilities. Which road to go?

    SciTech Connect

    Kaupp, A.

    1996-12-31

    Five conditions, at minimum, should be examined in the comparative analysis of CO{sub 2}-mitigation options for the power sector. Under the continuing constraint of scarce financial resources for any private or public investment in the power sector, the following combination of requirements characterise a successful CO{sub 2}-mitigation project: (1) Financial attractiveness for private or public investors. (2) Low, or even negative, long range marginal costs per ton of `CO{sub 2} saved`. (3) High impact on CO{sub 2}-mitigation, which indicates a large market potential for the measure. (4) The number of individual investments required to achieve the impact is relatively small. In other words, logistical difficulties in project implementation are minimised. (5) The projects are `socially fair` and have minimal negative impact on any segment of the society. This paper deals with options to reduce carbonaceous fuel burning in the power sector. Part I explains how projects should be selected and classified. Part II describes the technical options. Since reduction of carbonaceous fuel burning may be achieved through Demand Side Management (DSM) and Supply Side Management (SSM) both are treated. Within the context of this paper SSM does not mean to expand power supply as demand grows. It means to economically generate and distribute power as efficiently as possible. In too many instances DSM has degenerated into efficient lighting programs and utility managed incentives and rebate programs. To what extent this is a desirable situation for utilities in Developing Countries that face totally different problems as their counterparts in highly industrialised countries remains to be seen. Which road to go is the topic of this paper.

  9. Air-to-fuel ratio control and its effects in a lean-burn natural gas engine

    SciTech Connect

    Hassaneen, A.E.; Varde, K.S.; Bawady, A.H.; Abdul Aziz, A.A.M.

    1996-12-31

    An experimental investigation was undertaken to examine air-to-fuel (A/F) ratio effects on performance and emission of a fuel injected, lean-burn natural gas engine. An eight cylinder, 4.6 liter spark ignited (SI) engine was used in the study. The engine had a compression ratio of 10.6 and was fuel injected with multi-point injection system. The injection and ignition systems of the engine were controlled by an external controller allowing the engine to operate on equivalence ratios as lean as 0.6. A wide range oxygen sensor, calibrated for natural gas, was used to monitor A/F ratio and its variation at steady state engine operation. The overall A/F ratio variations at lean, steady state operating condition, were found to be very low, an average of about {+-}1%, at an equivalence ratio of 0.6. At these conditions hydrocarbons in engine out exhaust, which were primarily made up of methane, increased to about 13 g/kW-h at medium and relatively high loads while the oxides of nitrogen were significantly reduced to below 0.6 g/kW-h. Furthermore, coefficient of variation in hydrocarbons and oxides of nitrogen were much lower than those realized in an earlier study where a four cylinder engine with gaseous carburetion system was used. The fuel injection system was found to maintain the overall A/F ratio much better than in a gaseous carburetion system thus resulting in very stable engine operation.

  10. Determination of the emissions from an aircraft auxiliary power unit (APU) during the Alternative Aviation Fuel Experiment (AAFEX).

    PubMed

    Kinsey, John S; Timko, Michael T; Herndon, Scott C; Wood, Ezra C; Yu, Zhenhong; Miake-Lye, Richard C; Lobo, Prem; Whitefield, Philip; Hagen, Donald; Wey, Changlie; Anderson, Bruce E; Beyersdorf, Andreas J; Hudgins, Charles H; Thornhill, K Lee; Winstead, Edward; Howard, Robert; Bulzan, Dan I; Tacina, Kathleen B; Knighton, W Berk

    2012-04-01

    The emissions from a Garrett-AiResearch (now Honeywell) Model GTCP85-98CK auxiliary power unit (APU) were determined as part of the National Aeronautics and Space Administration's (NASA's) Alternative Aviation Fuel Experiment (AAFEX) using both JP-8 and a coal-derived Fischer Tropsch fuel (FT-2). Measurements were conducted by multiple research organizations for sulfur dioxide (SO2, total hydrocarbons (THC), carbon monoxide (CO), carbon dioxide (CO2), nitrogen oxides (NOx), speciated gas-phase emissions, particulate matter (PM) mass and number, black carbon, and speciated PM. In addition, particle size distribution (PSD), number-based geometric mean particle diameter (GMD), and smoke number were also determined from the data collected. The results of the research showed PM mass emission indices (EIs) in the range of 20 to 700 mg/kg fuel and PM number EIs ranging from 0.5 x 10(15) to 5 x 10(15) particles/kg fuel depending on engine load and fuel type. In addition, significant reductions in both the SO2 and PM EIs were observed for the use of the FT fuel. These reductions were on the order of approximately 90% for SO2 and particle mass EIs and approximately 60% for the particle number EI, with similar decreases observed for black carbon. Also, the size of the particles generated by JP-8 combustion are noticeably larger than those emitted by the APU burning the FT fuel with the geometric mean diameters ranging from 20 to 50 nm depending on engine load and fuel type. Finally, both particle-bound sulfate and organics were reduced during FT-2 combustion. The PM sulfate was reduced by nearly 100% due to lack of sulfur in the fuel, with the PM organics reduced by a factor of approximately 5 as compared with JP-8.

  11. Engine Conceptual Design Studies for a Hybrid Wing Body Aircraft

    NASA Technical Reports Server (NTRS)

    Tong, Michael T.; Jones, Scott M.; Haller, William J.; Handschuh, Robert F.

    2009-01-01

    Worldwide concerns of air quality and climate change have made environmental protection one of the most critical issues in aviation today. NASA's current Fundamental Aeronautics research program is directed at three generations of aircraft in the near, mid and far term, with initial operating capability around 2015, 2020, and 2030, respectively. Each generation has associated goals for fuel burn, NOx, noise, and field-length reductions relative to today's aircrafts. The research for the 2020 generation is directed at enabling a hybrid wing body (HWB) aircraft to meet NASA's aggressive technology goals. This paper presents the conceptual cycle and mechanical designs of the two engine concepts, podded and embedded systems, which were proposed for a HWB cargo freighter. They are expected to offer significant benefits in noise reductions without compromising the fuel burn.

  12. Engine Conceptual Design Studies for a Hybrid Wing Body Aircraft

    NASA Technical Reports Server (NTRS)

    Tong, Michael T.; Jones, Scott M.; Haller, William J.; Handschuh, Robert F.

    2009-01-01

    Worldwide concerns of air quality and climate change have made environmental protection one of the most critical issues in aviation today. NASA s current Fundamental Aeronautics Research program is directed at three generations of aircraft in the near, mid and far term, with initial operating capability around 2015, 2020, and 2030, respectively. Each generation has associated goals for fuel burn, NOx, noise, and field-length reductions relative to today s aircrafts. The research for the 2020 generation is directed at enabling a hybrid wing body (HWB) aircraft to meet NASA s aggressive technology goals. This paper presents the conceptual cycle and mechanical designs of the two engine concepts, podded and embedded systems, which were proposed for a HWB cargo freighter. They are expected to offer significant benefits in noise reductions without compromising the fuel burn.

  13. Particulate and Trace Gas Emissions from Prescribed Burns in Southeastern U.S. fuel types: Summary of a 5-year Project

    SciTech Connect

    Weise, David; Johnson, Timothy J.; Reardon, James

    2015-05-01

    Prescribed burning is an accepted practice to manage biomass in the United States and throughout the world. It is a particularly important practice in pine forests throughout the world, many of which have evolved in the presence of fire [1]. A recent survey [2] of prescribed fire use reported that 2.62 x 106 ha of forest land in the southeastern U.S. (defined by the National Association of State Foresters) burned in 2011 for silvicultural purposes such as hazardous fuel reduction, wildlife habitat improvement, and forest regeneration. Earlier surveys reported 0.9 to 1.7 x 106 ha of prescribed burning in the southern U.S. [3–5] using different survey techniques. While it is not possible to determine confidence intervals on these estimates, it is clear that the use of prescribed burning has increased since the first published estimate of 1 x 106 ha we were able to locate or the recent survey captured more information. Smoke is an important consequence of prescribed burning that must be managed, [6] and a great deal of research has been performed since the 1970s trying to characterize the composition, production, and transport of smoke from such fires. A recent review of the state of science behind estimation of the contribution of wildland fire to greenhouse gases and black carbon in the U.S. identified several areas of research that must be performed [7]. In particular, two areas of knowledge that still need improvement are fuel characterization and smoke emissions, and the correlation(s) between the two. While many fuel types in the southeastern U.S. have been described for fire behavior and fire danger prediction, characterization of fuel bed components important for smoke production is more limited. Emissions characterization, both chemical and particulate, is needed to determine potential impacts of prescribed burning on nutrient cycling, planetary albedo, human health, and highway visibility [e.g. 8–10].

  14. Experimental Studies of Coal and Biomass Fuel Synthesis and Flame Characterization for Aircraft Engines

    DTIC Science & Technology

    2012-03-31

    Synthesis and Flame Characterization for Aircraft Engines 5a. CONTRACT NUMBER 5b. GRANT NUMBER FA9550-10-1-0344 5c. PROGRAM ELEMENT NUMBER 61102F... Flame Characterization for Aircraft Engines AFOSR Grant Number: FA9550-10-1-0344 Final Performance Report Report Period: September 1, 2008 to... Flame Characterization for Aircraft Engines (Final Performance Report) Project Period: September 1, 2008 to March 31, 2012 Report Period

  15. Process for clean-burning fuel from low-rank coal

    DOEpatents

    Merriam, N.W.; Sethi, V.; Brecher, L.E.

    1994-06-21

    A process is described for upgrading and stabilizing low-rank coal involving the sequential processing of the coal through three fluidized beds; first a dryer, then a pyrolyzer, and finally a cooler. The fluidizing gas for the cooler is the exit gas from the pyrolyzer with the addition of water for cooling. Overhead gas from pyrolyzing is likely burned to furnish the energy for the process. The product coal exits with a tar-like pitch sealant to enhance its safety during storage. 1 fig.

  16. High turbulence combustion chamber for turbocharged lean burn gaseous fueled engine

    SciTech Connect

    Joyce, R.S.

    1988-12-27

    This patent describes a gaseous fueled engine having at least a cylinder with an fuel/air intake and combustion product exhaust to be used in a cylinder head having a flat lower surface enclosing one end of the cylinder, and a piston with a flat top piston head slidably received in the cylinder. The improvement consists of: a. an ignition device extending from the flat lower surface of the cylinder head in the center of the cylinder, and b. a baffleless combustion chamber eccentrically located in the head of the piston with respect to the piston axis such that ignition of the fuel/air mixture by the ignition device occurs within but on the outer periphery of the combustion chamber.

  17. Alcohol fuels for aviation

    SciTech Connect

    Schauffler, P.

    1982-06-01

    The ten-fold increase in aviation fuel prices in eight years has caused a reassessment of alcohol fuels. In a recent test, methanol fuel-flow rate was high at takeoff, and levelled off at 10,000 feet, but above 18,000 fell 30% below avgas use. Because methanol sells thirty cents below avgas per gallon it is already an attractive fuel for piston-engine aircraft. But as 95% of aviation fuel is burned as kerosene in turbines a test program has been set up to look at the performance of small shaft turbine engines with various combinations of alcohols and water, and of straight methanol, and to look at major thrust engine at optimum fuel as well. These tests should determine the overall alcohol potentials for aviation. The tests will also tell if the breakthrough will be modest or major.

  18. Aerolization During Boron Nanoparticle Multi-Component Fuel Group Burning Studies

    DTIC Science & Technology

    2014-02-03

    Oleic Acid-coated Boron (or B4C) nanoparticles with a Cerium Oxide (CeO2) catalyst to enhance energy density of conventional aviation fuels, such as...milling time. X-ray photoelectron spectroscopy measurements on boron nanoparticle batches detected cerium boride indicating that the CeO2

  19. Heat Transfer and Thermal Stability of Alternative Aircraft Fuels. Volume 1.

    DTIC Science & Technology

    1983-11-01

    conditions to the rate of deposit accumulation for each fuel. An engine fuel system analysis will be performed to evaluate the environmental history of...improve the correlative model The fuel deposition-rate data will be related to the engine fuel system environmental - history analysis in order to

  20. In situ laser measurements of CO and CH4 close to the surface of a burning single fuel particle

    NASA Astrophysics Data System (ADS)

    Lackner, M.; Totschnig, G.; Winter, F.; Maiorov, M. A.; Garbuzov, D. Z.; Connolly, J. C.

    2002-10-01

    The combustion behaviour of three different fuels, bituminous coal, beech wood and fir wood, was investigated by monitoring the concentrations of CO, CH4, CO2 and O2 during devolatilization and char combustion. Single fuel particles (4-6 mm diameter, 55 mm in length) were positioned in the freeboard of a laboratory-scale fluidized bed combustor. The superficial velocity was 0.3 m s-1. Tunable diode laser absorption spectroscopy was used to investigate in situ the concentration histories of the evolving species CO and CH4. An InGaAsSb/AlGaAsSb diode laser was frequency tuned around 2.3 µm at 300 Hz and traversed the reactor directly above the particle. This enabled for the first time, to the knowledge of the authors, the accurate measurement of species concentrations close to the surface of a burning particle. The influence of the oxygen partial pressure (5, 10, 15, 21 kPa), the bed temperature (700, 800, 900̂C), the distance of the laser beam from the particle (4, 10, 21, 31 mm) and hence the residence time (12, 30, 60, 90 ms), the particle size (4, 6 mm diameter) and the fuel type were investigated by independently changing these governing parameters. Conventional methods were deployed to determine CO, CO2 and O2 in the exhaust gas. The evolving CO could be tracked down to 12 ms after its generation. Biomass was found to produce four times as much CO as coal. The CO/CO2 ratio was found to be about five times higher for beech wood (a typical hardwood) than for fir wood (a typical softwood). The comparison of the in situ results with conventionally measured concentrations showed that the CO is normally underestimated during devolatilization and overestimated during char combustion. The discrepancy was attributed to more efficient degradation mechanisms for CO during devolatilization.

  1. Biomass fuel burning and its implications: deforestation and greenhouse gases emissions in Pakistan.

    PubMed

    Tahir, S N A; Rafique, M; Alaamer, A S

    2010-07-01

    Pakistan is facing problem of deforestation. Pakistan lost 14.7% of its forest habitat between 1990 and 2005 interval. This paper assesses the present forest wood consumption rate by 6000 brick kilns established in the country and its implications in terms of deforestation and emission of greenhouse gases. Information regarding consumption of forest wood by the brick kilns was collected during a manual survey of 180 brick kiln units conducted in eighteen provincial divisions of country. Considering annual emission contributions of three primary GHGs i.e., CO(2), CH(4) and N(2)O, due to burning of forest wood in brick kiln units in Pakistan and using IPCC recommended GWP indices, the combined CO(2)-equivalent has been estimated to be 533019 t y(-1).

  2. Electron probe microanalysis of a METAPHIX UPuZr metallic alloy fuel irradiated to 7.0 at.% burn-up

    NASA Astrophysics Data System (ADS)

    Brémier, S.; Inagaki, K.; Capriotti, L.; Poeml, P.; Ogata, T.; Ohta, H.; Rondinella, V. V.

    2016-11-01

    The METAPHIX project is a collaboration between CRIEPI and JRC-ITU investigating safety and performance of a closed fuel cycle option based on fast reactor metal alloy fuels containing Minor Actinides (MA). The aim of the project is to investigate the behaviour of this type of fuel and demonstrate the transmutation of MA under irradiation. A UPuZr metallic fuel sample irradiated to a burn-up of 7 at.% was examined by electron probe microanalysis. The fuel sample was extensively characterised qualitatively and quantitatively using elemental X-ray imaging and point analysis techniques. The analyses reveal a significant redistribution of the fuel components along the fuel radius highlighting a nearly complete depletion of Zr in the central part of the fuel. Numerous rare earth and fission products secondary phases are present in various compositions. Fuel cladding chemical interaction was observed with creation of a number of intermediary layers affecting a cladding depth of 15-20 μm and migration of cladding elements to the fuel.

  3. Elimination of dimethyl methylphosphonate by plasma flame made of microwave plasma and burning hydrocarbon fuel

    NASA Astrophysics Data System (ADS)

    Cho, S. C.; Uhm, H. S.; Hong, Y. C.; Park, Y. G.; Park, J. S.

    2008-06-01

    Elimination of dimethyl methylphosphonate (DMMP) in liquid phase was studied by making use of a microwave plasma burner, exhibiting a safe removal capability of stockpiled chemical weapons. The microwave plasma burner consisted of a fuel injector and a plasma flame exit connected in series to a microwave plasma torch. The burner flames were sustained by injecting hydrocarbon fuels into the microwave plasma torch in air discharge. The Fourier transform infrared spectra indicated near perfect elimination of DMMP in the microwave plasma burner. This was confirmed by gas chromatography spectra as supporting data, revealing the disappearance of even intermediary compounds in the process of DMMP destruction. The experimental results and the physical configuration of the microwave plasma burner may provide an effective means of on-site removal of chemical warfare agents found on a battlefield.

  4. Elimination of dimethyl methylphosphonate by plasma flame made of microwave plasma and burning hydrocarbon fuel

    SciTech Connect

    Cho, S. C.; Uhm, H. S.; Hong, Y. C.; Park, Y. G.; Park, J. S.

    2008-06-15

    Elimination of dimethyl methylphosphonate (DMMP) in liquid phase was studied by making use of a microwave plasma burner, exhibiting a safe removal capability of stockpiled chemical weapons. The microwave plasma burner consisted of a fuel injector and a plasma flame exit connected in series to a microwave plasma torch. The burner flames were sustained by injecting hydrocarbon fuels into the microwave plasma torch in air discharge. The Fourier transform infrared spectra indicated near perfect elimination of DMMP in the microwave plasma burner. This was confirmed by gas chromatography spectra as supporting data, revealing the disappearance of even intermediary compounds in the process of DMMP destruction. The experimental results and the physical configuration of the microwave plasma burner may provide an effective means of on-site removal of chemical warfare agents found on a battlefield.

  5. Ignition and Supersonic Burning of Air - Fuel Mixtures Initiated by Electrical Discharges

    DTIC Science & Technology

    2005-08-04

    second order accuracy is used. On every time step the flowfield parameters are computed due Gauss - Seidel line relaxation numerical technique. inv GF...flame plasma is undertaken by the spectroscopy methods in the first section of the combustor (directly behind the step) and in the diagnostic chamber...bottom wall, 8 – fuel supply into the flame holder zones 1.3. Diagnostic complex. Main experimental methods of plasma discharges

  6. Aircraft Fuel, Fuel Metering, Induction and Exhaust Systems (Course Outline), Aviation Mechanics (Power Plant): 9057.02.

    ERIC Educational Resources Information Center

    Dade County Public Schools, Miami, FL.

    This document presents an outline for a 135-hour course designed to help the trainee gain the skills and knowledge necessary to become an aviation powerplant mechanic. The course outlines the theory of operation of various fuel systems, fuel metering, induction, and exhaust system components with an emphasis on troubleshooting, maintenance, and…

  7. The impact of fuels on aircraft technology through the year 2000

    NASA Technical Reports Server (NTRS)

    Grobman, J.; Reck, G. M.

    1980-01-01

    In the future, it may be necessary to use jet fuels with a broader range of properties in order to insure a more flexible and reliable supply and to minimize energy consumption and processing costs at the refinery. This paper describes research being conducted to (1) determine the potential range of properties for future jet fuels, (2) establish a data base of fuel property effects on propulsion system components, (3) evolve and evaluate advanced component technology that would permit the use of broader property fuels and (4) identify technical and economic trade-offs within the overall fuel production-air transportation system associated with variations in fuel properties.

  8. All-Russia Thermal Engineering Institute experience in using difficult to burn fuels in the power industry

    NASA Astrophysics Data System (ADS)

    Tugov, A. N.; Ryabov, G. A.; Shtegman, A. V.; Ryzhii, I. A.; Litun, D. S.

    2016-07-01

    This article presents the results of the research carried out at the All-Russia Thermal Engineering Institute (VTI) aimed at using saline coal, municipal solid waste and bark waste, sunflower husk, and nesting/ manure materials from poultry farms. The results of saline coal burning experience in Troitsk and Verkhny Tagil thermal power plants (TPP) show that when switching the boiler to this coal, it is necessary to take into account its operating reliability and environmental safety. Due to increased chlorine content in saline coal, the concentration of hydrogen chloride can make over 500 mg/m3. That this very fact causes the sharp increase of acidity in sludge and the resulting damage of hydraulic ash removal system equipment at these power stations has been proven. High concentration of HCl can trigger damage of the steam superheater due to high-temperature corrosion and result in a danger of low-temperature corrosion of air heating surfaces. Besides, increased HCl emissions worsen the environmental characteristics of the boiler operation on the whole. The data on waste-to-energy research for municipal solid waste (MSW) has been generalized. Based on the results of mastering various technologies of MSW thermal processing at special plants nos. 2 and 4 in Moscow, as well as laboratory, bench, and industrial studies, the principal technical solutions to be implemented in the modern domestic thermal power plant with the installed capacity of 24 MW and MSW as the primary fuel type has been developed. The experience of the VTI in burning various kinds of organic waste—bark waste, sunflower husk, and nesting/manure materials from poultry farms—has been analyzed.

  9. Experimental and numerical studies of burning velocities and kinetic modeling for practical and surrogate fuels

    NASA Astrophysics Data System (ADS)

    Zhao, Zhenwei

    To help understand the fuel oxidation process in practical combustion environments, laminar flame speeds and high temperature chemical kinetic models were studied for several practical fuels and "surrogate" fuels, such as propane, dimethyl ether (DME), and primary reference fuel (PRF) mixtures, gasoline and n-decane. The PIV system developed for the present work is described. The general principles for PIV measurements are outlined and the specific considerations are also reported. Laminar flame speeds were determined for propane/air over a range of equivalence ratios at initial temperature of 298 K, 500 K and 650 K and atmospheric pressure. Several data sets for propane/air laminar flame speeds with N 2 dilution are also reported. These results are compared to the literature data collected at the same conditions. The propane flame speed is also numerically calculated with a detailed kinetic model and multi component diffusion, including Soret effects. This thesis also presents experimentally determined laminar flame speeds for primary reference fuel (PRF) mixtures of n-heptane/iso-octane and real gasoline fuel at different initial temperature and at atmospheric pressure. Nitrogen dilution effects on the laminar flame speed are also studied for selected equivalence ratios at the same conditions. A minimization of detailed kinetic model for PRF mixtures on laminar flame speed conditions was performed and the measured flame speeds were compared with numerical predictions using this model. The measured laminar flame speeds of n-decane/air mixtures at 500 K and at atmospheric pressure with and without dilution were determined. The measured flame speeds are significantly different that those predicted using existing published kinetic models, including a model validated previously against high temperature data from flow reactor, jet-stirred reactor, shock tube ignition delay, and burner stabilized flame experiments. A significant update of this model is described which

  10. Impact of broad-specification fuels on future jet aircraft. [engine components and performance

    NASA Technical Reports Server (NTRS)

    Grobman, J. S.

    1978-01-01

    The effects that broad specification fuels have on airframe and engine components were discussed along with the improvements in component technology required to use broad specification fuels without sacrificing performance, reliability, maintainability, or safety.

  11. Fuel Preheat Effects on Soot-Field Structure in Laminar Gas Jet Diffusion Flames Burning in 0-g and 1-g

    NASA Technical Reports Server (NTRS)

    Konsur, Bogdan; Megaridis, Constantine M.; Griffin, Devon W.

    1999-01-01

    An experimental investigation conducted at the 2.2-s drop tower of the NASA Lewis Research Center is presented to quantify the influence of moderate fuel preheat on soot-field structure within 0-g laminar gas jet diffusion flames. Parallel work in 1-g is also presented to delineate the effect of elevated fuel temperatures on soot-field structure in buoyant flames. The experimental methodology implements jet diffusion flames of nitrogen-diluted acetylene fuel burning in quiescent air at atmospheric pressure. Fuel preheat of approximately 100 K in the 0-g laminar jet diffusion flames is found to reduce soot loadings in the annular region, but causes an increase in soot volume fractions at the centerline. In addition, fuel preheat reduces the radial extent of the soot field in 0-g. In 1-g, the same fuel preheat levels have a more moderated influence on soot loadings in the annular region, but are also seen to enhance soot concentrations near the axis low in the flame. The increased soot loadings near the flame centerline, as caused by fuel preheat, are consistent with the hypothesis that preheat levels of approximately 100 K enhance fuel pyrolysis rates. The results show that the growth stage of particles transported along the soot annulus is shortened both in 1-g and 0-g when elevated fuel temperatures are used.

  12. A new direction in energy conversion - The all-electric aircraft

    NASA Astrophysics Data System (ADS)

    Spitzer, C. R.

    1985-12-01

    This paper reviews recent studies of all-electric aircraft that use electric-only secondary power and flight critical fly-by-wire flight controls, and brings to the attention of the power system designer the intrinsic advantages of such aircraft. The all-electric aircraft is made possible by the development of rare earth magnet materials and fault tolerant systems technologies. Recent studies have shown all-electric aircraft to be more efficient than conventional designs and offer substantial operating costs reductions. Compared to present aircraft, an all-electric transport can save at least 10 percent in fuel burn. The cornerstone of an all-electric aircraft is the electric secondary power system. This paper reviews the major features of flight critical electric secondary power systems. Research required to lay the foundation for an all-electric aircraft is briefly discussed.

  13. A new direction in energy conversion - The all-electric aircraft

    NASA Technical Reports Server (NTRS)

    Spitzer, C. R.

    1985-01-01

    This paper reviews recent studies of all-electric aircraft that use electric-only secondary power and flight critical fly-by-wire flight controls, and brings to the attention of the power system designer the intrinsic advantages of such aircraft. The all-electric aircraft is made possible by the development of rare earth magnet materials and fault tolerant systems technologies. Recent studies have shown all-electric aircraft to be more efficient than conventional designs and offer substantial operating costs reductions. Compared to present aircraft, an all-electric transport can save at least 10 percent in fuel burn. The cornerstone of an all-electric aircraft is the electric secondary power system. This paper reviews the major features of flight critical electric secondary power systems. Research required to lay the foundation for an all-electric aircraft is briefly discussed.

  14. Corrosion of aluminum alloy 2024 by microorganisms isolated from aircraft fuel tanks.

    PubMed

    McNamara, Christopher J; Perry, Thomas D; Leard, Ryan; Bearce, Ktisten; Dante, James; Mitchell, Ralph

    2005-01-01

    Microorganisms frequently contaminate jet fuel and cause corrosion of fuel tank metals. In the past, jet fuel contaminants included a diverse group of bacteria and fungi. The most common contaminant was the fungus Hormoconis resinae. However, the jet fuel community has been altered by changes in the composition of the fuel and is now dominated by bacterial contaminants. The purpose of this research was to determine the composition of the microbial community found in fuel tanks containing jet propellant-8 (JP-8) and to determine the potential of this community to cause corrosion of aluminum alloy 2024 (AA2024). Isolates cultured from fuel tanks containing JP-8 were closely related to the genus Bacillus and the fungi Aureobasidium and Penicillium. Biocidal activity of the fuel system icing inhibitor diethylene glycol monomethyl ether is the most likely cause of the prevalence of endospore forming bacteria. Electrochemical impedance spectroscopy and metallographic analysis of AA2024 exposed to the fuel tank environment indicated that the isolates caused corrosion of AA2024. Despite the limited taxonomic diversity of microorganisms recovered from jet fuel, the community has the potential to corrode fuel tanks.

  15. An extended version of the SERPENT-2 code to investigate fuel burn-up and core material evolution of the Molten Salt Fast Reactor

    NASA Astrophysics Data System (ADS)

    Aufiero, M.; Cammi, A.; Fiorina, C.; Leppänen, J.; Luzzi, L.; Ricotti, M. E.

    2013-10-01

    In this work, the Monte Carlo burn-up code SERPENT-2 has been extended and employed to study the material isotopic evolution of the Molten Salt Fast Reactor (MSFR). This promising GEN-IV nuclear reactor concept features peculiar characteristics such as the on-line fuel reprocessing, which prevents the use of commonly available burn-up codes. Besides, the presence of circulating nuclear fuel and radioactive streams from the core to the reprocessing plant requires a precise knowledge of the fuel isotopic composition during the plant operation. The developed extension of SERPENT-2 directly takes into account the effects of on-line fuel reprocessing on burn-up calculations and features a reactivity control algorithm. It is here assessed against a dedicated version of the deterministic ERANOS-based EQL3D procedure (PSI-Switzerland) and adopted to analyze the MSFR fuel salt isotopic evolution. Particular attention is devoted to study the effects of reprocessing time constants and efficiencies on the conversion ratio and the molar concentration of elements relevant for solubility issues (e.g., trivalent actinides and lanthanides). Quantities of interest for fuel handling and safety issues are investigated, including decay heat and activities of hazardous isotopes (neutron and high energy gamma emitters) in the core and in the reprocessing stream. The radiotoxicity generation is also analyzed for the MSFR nominal conditions. The production of helium and the depletion in tungsten content due to nuclear reactions are calculated for the nickel-based alloy selected as reactor structural material of the MSFR. These preliminary evaluations can be helpful in studying the radiation damage of both the primary salt container and the axial reflectors.

  16. Acid rain: commentary on controversial issues and observations on the role of fuel burning

    SciTech Connect

    Szabo, M.F.; Esposito, M.P.; Spaite, P.W.

    1982-03-01

    Even though much information has been accumulated on the subject of acid precipitation, lack of knowledge in certain technical areas precludes an adequate understanding of (1) how serious the acid precipitation problem really is and (2) what effect controlling sources of acid precipitation precursors would have in reducing acidification. It is nevertheless possible to draw some broad conclusions regarding the problem and to ascertain the direction that the required further work should take. This report presents the results of an investigation of various issues associated with acid rain. The following topics are addressed: occurrence of acid precipitation; effects of acid precipitation; sources of acid precipitation; transport, transformation, and deposition of acid pollutants; and fuel trend analysis. Recommendations for further research are included. (DMC)

  17. Investigation of Critical Burning of Fuel Droplets. [of liquid rocket propellant

    NASA Technical Reports Server (NTRS)

    Chanin, S. P.; Shearer, A. J.; Faeth, G. M.

    1976-01-01

    An earlier analysis for the combustion response of a liquid monopropellant strand (hydrazine) was extended to consider individual droplets and sprays. While small drops gave low or negative response, large droplets provided response near unity at low frequencies, with the response declining at frequencies greater than the characteristic liquid phase frequency. Temperature gradients in the liquid phase resulted in response peaks greater than unity. A second response peak was found for large drops which corresponded to gas phase transient effects. Spray response was generally reduced from the response of the largest injected droplet, however, even a small percentage of large droplets can yield appreciable response. An apparatus was designed and fabricated to allow observation of bipropellant fuel spray combustion at elevated pressures. A locally homogeneous model was developed to describe this combustion process which allows for high pressure phenomena associated with the thermodynamic critical point.

  18. Feasibility of burning refuse derived fuel in institutional size oil-fired boilers. Final report

    SciTech Connect

    1980-10-01

    This study investigates the feasibility of retrofitting existing oil-fired boilers of institutional size, approximately 3.63 to 36.3 Mg steam/h (8000 to 80,000 lbs steam/h) for co-firing with refuse-derived fuel (RDF). Relevant quantities describing mixtures of oil and RDF and combustion products for various levels of excess air are computed. Savings to be realized from the use of RDF are derived under several assumptions and allowable costs for a retrofit are estimated. An extensive survey of manufacturers of burners, boilers, and combustion systems showed that no hardware or proven design is yet available for such retrofit. Approaches with significant promises are outlined: the slagging burner, and a dry ash double vortex burner for low heat input from RDF. These two systems, and an evaluation of a small separate RDF dedicated combustor in support of the oil-fired boiler, are recommended as topics for future study.

  19. Particulate and trace gas emissions from prescribed burns in southeastern U.S. fuel types: Summary of a 5-year project

    SciTech Connect

    Weise, David; Johnson, Timothy J.; Reardon, James

    2015-03-04

    Management of smoke from prescribed fires requires knowledge of fuel quantity and the amount and composition of the smoke produced by the fire to minimize adverse impacts on human health. A five-year study produced new emissions information for more than 100 trace gases and particulate matter in smoke for fuel types found in the southern United States of America using state-of-the-art instrumentation in both laboratory and field experiments. Emission factors for flaming, smoldering, and residual smoldering were developed. Agreement between laboratory and field-derived emission factors was generally good in most cases. Reference spectra of over 50 wildland fire gas-phase smoke components were added to a publicly-available database to support identification via infrared spectroscopy. Fuel loading for the field experiments was similar to previously measured fuels. This article summarizes the results of a five-year study to better understand the composition of smoke during all phases of burning for such forests.

  20. On the oxidation state of UO 2 nuclear fuel at a burn-up of around 100 MWd/kgHM

    NASA Astrophysics Data System (ADS)

    Walker, C. T.; Rondinella, V. V.; Papaioannou, D.; Winckel, S. Van; Goll, W.; Manzel, R.

    2005-10-01

    Results for the radial distribution of the oxygen potential and stoichiometry of a PWR fuel with an average pellet burn-up of 102 MWd/kgHM are presented. The local Δ G bar (O2) of the fuel was measured using a miniature solid state galvanic cell, the local O/U ratio was calculated from the lattice parameter measured by micro-X-ray diffraction and the local O/M ratio was derived from the fuel composition determined by ICP-MS. During irradiation the O/U ratio of the fuel decreased from 2.005 to 1.991 ± 0.008. The average fuel O/M ratio was 1.973 compared with the stoichiometric value of 1.949. The amount of free oxygen in the fuel, represented by the difference between these two quantities, increased from the centre to periphery of the pellet. Similarly, the Δ G bar (O2) of the fuel increased from -370 kJ mol-1 at r/r0 = 0.1 to -293 kJ mol-1 at r/r0 = 0.975. Thus, the Δ G bar (O2) of the fuel had not been buffered by the oxidation of fission product Mo. About one-quarter of the free oxygen accumulated during the irradiation had been gettered by the Zircaloy cladding.

  1. The Influence of Fuel Moisture, Charge Size, Burning Rate and Air Ventilation Conditions on Emissions of PM, OC, EC, Parent PAHs, and Their Derivatives from Residential Wood Combustion

    PubMed Central

    Shen, Guofeng; Xue, Miao; Wei, Siye; Chen, Yuanchen; Wang, Bin; Wang, Rong; Lv, Yan; Shen, Huizhong; Li, Wei; Zhang, Yanyan; Huang, Ye; Chen, Han; Wei, Wen; Zhao, Qiuyue; Li, Bin; Wu, Haisuo; TAO, Shu

    2014-01-01

    Controlled combustion experiments were conducted to investigate the influence of fuel charge size, moisture, air ventilation and burning rate on the emission factors (EFs) of carbonaceous particulate matter, parent polycyclic aromatic hydrocarbons (pPAHs) and their derivatives from residential wood combustion in a typical brick cooking stove. Measured EFs were found to be independent of fuel charge size, but increased with increasing fuel moisture. Pollution emissions from a normal burning under an adequate air supply condition were the lowest for most pollutants, while more pollutants were emitted when the oxygen deficient atmosphere was formed in stove chamber during fast burning. The impact of these 4 factors on particulate matter size distribution was also studied. Modified combustion efficiency and the four investigated factors explained 68, 72, and 64% of total variations in EFs of PM, organic carbon, and oxygenated PAHs, respectively, but only 36, 38 and 42% of the total variations in EFs of elemental carbon, pPAHs and nitro-PAHs, respectively. PMID:24520723

  2. High Temperature Reactor (HTR) Deep Burn Core and Fuel Analysis: Design Selection for the Prismatic Block Reactor With Results from FY-2011 Activities

    SciTech Connect

    Michael A. Pope

    2011-10-01

    The Deep Burn (DB) Project is a U.S. Department of Energy sponsored feasibility study of Transuranic Management using high burnup fuel in the high temperature helium cooled reactor (HTR). The DB Project consists of seven tasks: project management, core and fuel analysis, spent fuel management, fuel cycle integration, TRU fuel modeling, TRU fuel qualification, and HTR fuel recycle. In the Phase II of the Project, we conducted nuclear analysis of TRU destruction/utilization in the HTR prismatic block design (Task 2.1), deep burn fuel/TRISO microanalysis (Task 2.3), and synergy with fast reactors (Task 4.2). The Task 2.1 covers the core physics design, thermo-hydraulic CFD analysis, and the thermofluid and safety analysis (low pressure conduction cooling, LPCC) of the HTR prismatic block design. The Task 2.3 covers the analysis of the structural behavior of TRISO fuel containing TRU at very high burnup level, i.e. exceeding 50% of FIMA. The Task 4.2 includes the self-cleaning HTR based on recycle of HTR-generated TRU in the same HTR. Chapter IV contains the design and analysis results of the 600MWth DB-HTR core physics with the cycle length, the average discharged burnup, heavy metal and plutonium consumptions, radial and axial power distributions, temperature reactivity coefficients. Also, it contains the analysis results of the 450MWth DB-HTR core physics and the analysis of the decay heat of a TRU loaded DB-HTR core. The evaluation of the hot spot fuel temperature of the fuel block in the DB-HTR (Deep-Burn High Temperature Reactor) core under full operating power conditions are described in Chapter V. The investigated designs are the 600MWth and 460MWth DB-HTRs. In Chapter VI, the thermo-fluid and safety of the 600MWth DB-HTRs has been analyzed to investigate a thermal-fluid design performance at the steady state and a passive safety performance during an LPCC event. Chapter VII describes the analysis results of the TRISO fuel microanalysis of the 600MWth and 450

  3. Evaluation of the Effects of a Pipeline Flow Improver on Aircraft Fuel Systems

    DTIC Science & Technology

    1993-01-01

    number of revolutions, thrust, exhaust temperature, specific fuel consumption and endoscopic test showed no significant influence of the PDR on the...cut up into 2-inch segments. Each segment was rinsed with heptane, dried in a vacuum oven at 100 °C for 1 hour, and analyzed for carbon using a Leco RC... vacuum oven at 212 ’F for at least 30 minutes. The sections were then analysed using the Leco RC-412 Carbon Analyzer. FUEL ANALYSIS Selected fuel samples

  4. Experimental Studies of Coal and Biomass Fuel Synthesis and Flame Characterization for Aircraft Engines (Year Two)

    DTIC Science & Technology

    2011-03-31

    2.1 Experimental Investigation of Coal and Biomass Gasification using In-situ Diagnostics ................ 31  2.2 References...need for fundamental scientific and synergistic research in catalytic biomass fast-hydropyrolysis, advanced coal gasification and liquid fuel...experimental findings will improve the scientific knowledge of catalytic biomass fast-hydropyrolysis, coal/ biomass gasification and liquid fuel combustion

  5. ERBS fuel addendum: Pollution reduction technology program small jet aircraft engines, phase 3

    NASA Technical Reports Server (NTRS)

    Bruce, T. W.; Davis, F. G.; Kuhn, T. E.; Mongia, H. C.

    1982-01-01

    A Model TFE731-2 engine with a low emission, variable geometry combustion system was tested to compare the effects of operating the engine on Commercial Jet-A aviation turbine fuel and experimental referee broad specification (ERBS) fuels. Low power emission levels were essentially identical while the high power NOx emission indexes were approximately 15% lower with the EBRS fuel. The exhaust smoke number was approximately 50% higher with ERBS at the takeoff thrust setting; however, both values were still below the EPA limit of 40 for the Model TFE731 engine. Primary zone liner wall temperature ran an average of 25 K higher with ERBS fuel than with Jet-A. The possible adoption of broadened proprties fuels for gas turbine applications is suggested.

  6. Alternate-Fueled Combustor-Sector Emissions

    NASA Technical Reports Server (NTRS)

    Saxena, Nikita T.; Thomas, Anna E.; Shouse, Dale T.; Neuroth, Craig; Hendricks, Robert C.; Lynch, Amy; Frayne, Charles W.; Stutrud, Jeffrey S.; Corporan, Edwin; Hankins, Terry

    2013-01-01

    In order to meet rapidly growing demand for fuel, as well as address environmental concerns, the aviation industry has been testing alternate fuels for performance and technical usability in commercial and military aircraft. In order to make alternate fuels (and blends) a viable option for aviation, the fuel must be able to perform at a similar or higher level than traditional petroleum fuel. They also attempt to curb harmful emissions, and therefore a truly effective alternate fuel would emit at or under the level of currently used fuel. This report analyzes data from gaseous and particulate emissions of an aircraft combustor sector. The data were evaluated at various inlet conditions, including variation in pressure and temperature, fuel-to-air ratios, and percent composition of alternate fuel. Traditional JP-8+100 data were taken as a baseline, and blends of JP-8+100 with synthetic-paraffinic-kerosene (SPK) fuel (Fischer-Tropsch (FT)) were used for comparison. Gaseous and particulate emissions, as well as flame luminosity, were assessed for differences between FT composition of 0, 50, and 100 percent. The data show that SPK fuel (an FT-derived fuel) had slightly lower harmful gaseous emissions, and smoke number information corroborated the hypothesis that SPK-FT fuels are cleaner burning fuels.

  7. Design and simulation of a fuel cell hybrid emergency power system for a more electric aircraft: Evaluation of energy management schemes

    NASA Astrophysics Data System (ADS)

    Njoya Motapon, Souleman

    As the aircraft industries are moving toward more electric aircraft (MEA), the electrical peak load seen by the main and emergency generators becomes higher than in conventional aircraft. Consequently, there is a major concern regarding the aircraft emergency system, which consists of a ram air turbine (RAT) or air driven generator (ADG), to fulfill the load demand during critical situations; particularly at low aircraft speed where the output power is very low. A potential solution under study by most aircraft manufacturers is to replace the air turbine by a fuel cell hybrid system, consisting of fuel cell combined with other high power density sources such as supercapacitors or lithium-ion batteries. To ensure the fuel cell hybrid system will be able to meet the load demand, it must be properly designed and an effective energy management strategy must be tested with real situations load profile. This work aims at designing a fuel cell emergency power system of a more electric aircraft and comparing different energy management schemes (EMS); with the goal to ensure the load demand is fully satisfied within the constraints of each energy source. The fuel cell hybrid system considered in this study consists of fuel cell, lithium-ion batteries and supercapacitors, along with associated DC-DC and DC-AC converters. The energy management schemes addressed are state-of-the-art, most commonly used energy management techniques in fuel cell vehicle applications and include: the state machine control strategy, the rule based fuzzy logic strategy, the classical PI control strategy, the frequency decoupling/fuzzy logic control strategy and the equivalent consumption minimization strategy (ECMS). Moreover, a new optimal scheme based on maximizing the instantaneous energy of batteries/supercapacitors, to improve the fuel economy is proposed. An off-line optimization based scheme is also developed to ascertain the validity of the proposed strategy in terms of fuel consumption

  8. Trace gas emissions from burning Florida wetlands

    SciTech Connect

    Cofer, W.R. III; Levine, J.S.; LeBel, P.J. ); Winstead, E.L. ); Koller, A.M. Jr.; Hinkle, C.R. )

    1990-02-20

    Measurements of biomass burn-produced trace gases are presented that were obtained using a helicopter at low altitudes above burning Florida wetlands on November 9, 1987, and from both helicopter and light-aircraft samplings on November 7, 1988. Carbon dioxide (CO{sub 2}) normalized emission ratios ({Delta}X/{Delta}CO{sub 2}; V/V; where X is trace gas) for carbon monoxide (CO), hydrogen (H{sub 2}),methane (CH{sub 4}), total nonmethane hydrocarbons (TNMHC), and nitrous oxide (N{sub 2}O) were obtained over burning graminoid wetlands consisting primarily of Spartina bakeri and Juncas roemerianus. Some interspersed scrub oak (Querus spp) and saw palmetto (Screnoa repens) were also burned. No significant differences were observed in the emission ratios determined for these gases from samples collected over flaming, mixed, and smoldering phases of combustion during the 1987 fire. Combustion-categorized differences in emission ratios were small for the 1988 fire. Combustion efficiency was relatively good (low emission ratios for reduced gases) for both fires. The authors believe that the consistently low emissions ratios were a unique result of graminoid wetlands fires, in which the grasses and rushes (both small-size fuels) burned rapidly down to standing water and were quickly extinguished. Consequently, the efficiency of the combustion was good and the amount and duration of smoldering combustion was greatly diminished.

  9. Trace gas emissions from burning Florida wetlands

    NASA Astrophysics Data System (ADS)

    Cofer, Wesley R.; Levine, Joel S.; Winstead, Edward L.; Lebel, Peter J.; Koller, Albert M.; Hinkle, C. Ross

    1990-02-01

    Measurements of biomass burn-produced trace gases are presented that were obtained using a helicopter at low altitudes above burning Florida wetlands on November 9, 1987, and from both helicopter and light-aircraft samplings on November 7, 1988. Carbon dioxide (CO2) normalized emission ratios (ΔX/ΔCO2; V/V; where X is trace gas) for carbon monoxide (CO), hydrogen (H2), methane (CH4), total nonmethane hydrocarbons (TNMHC), and nitrous oxide (N2O) were obtained over burning graminoid wetlands consisting primarily of Spartina bakeri and Juncus roemerianus. Some interspersed scrub oak (Quercus spp) and saw palmetto (Screnoa repens) were also burned. No significant differences were observed in the emission ratios determined for these gases from samples collected over flaming, mixed, and smoldering phases of combustion during the 1987 fire. Combustion-categorized differences in emission ratios were small for the 1988 fire. Combustion efficiency was relatively good (low emission ratios for reduced gases) for both fires. We believe that the consistently low emission ratios were a unique result of graminoid wetlands fires, in which the grasses and rushes (both small-size fuels) burned rapidly down to standing water and were quickly extinguished. Consequently, the efficiency of the combustion was good and the amount and duration of smoldering combustion was greatly diminished.

  10. Performance evaluation of an advanced air-fuel ratio controller on a stationary, rich-burn natural gas engine

    NASA Astrophysics Data System (ADS)

    Kochuparampil, Roshan Joseph

    The advent of an era of abundant natural gas is making it an increasingly economical fuel source against incumbents such as crude oil and coal, in end-use sectors such as power generation, transportation and industrial chemical production, while also offering significant environmental benefits over these incumbents. Equipment manufacturers, in turn, are responding to widespread demand for power plants optimized for operation with natural gas. In several applications such as distributed power generation, gas transmission, and water pumping, stationary, spark-ignited, natural gas fueled internal combustion engines (ICEs) are the power plant of choice (over turbines) owing to their lower equipment and operational costs, higher thermal efficiencies across a wide load range, and the flexibility afforded to end-users when building fine-resolution horsepower topologies: modular size increments ranging from 100 kW -- 2 MW per ICE power plant compared to 2 -- 5 MW per turbine power plant. Under the U.S. Environment Protection Agency's (EPA) New Source Performance Standards (NSPS) and Reciprocating Internal Combustion Engine National Emission Standards for Hazardous Air Pollutants (RICE NESHAP) air quality regulations, these natural gas power plants are required to comply with stringent emission limits, with several states mandating even stricter emissions norms. In the case of rich-burn or stoichiometric natural gas ICEs, very high levels of sustained emissions reduction can be achieved through exhaust after-treatment that utilizes Non Selective Catalyst Reduction (NSCR) systems. The primary operational constraint with these systems is the tight air-fuel ratio (AFR) window of operation that needs to be maintained if the NSCR system is to achieve simultaneous reduction of carbon monoxide (CO), nitrogen oxides (NOx), total hydrocarbons (THC), volatile organic compounds (VOCs), and formaldehyde (CH 2O). Most commercially available AFR controllers utilizing lambda (oxygen

  11. Conversion of hydrocarbon fuel in thermal protection reactors of hypersonic aircraft

    NASA Astrophysics Data System (ADS)

    Kuranov, A. L.; Mikhaylov, A. M.; Korabelnikov, A. V.

    2016-07-01

    Thermal protection of heat-stressed surfaces of a high-speed vehicle flying in dense layers of atmosphere is one of the topical issues. Not of a less importance is also the problem of hydrocarbon fuel combustion in a supersonic air flow. In the concept under development, it is supposed that in the most high-stressed parts of airframe and engine, catalytic thermochemical reactors will be installed, wherein highly endothermic processes of steam conversion of hydrocarbon fuel take place. Simultaneously with heat absorption, hydrogen generation will occur in the reactors. This paper presents the results of a study of conversion of hydrocarbon fuel in a slit reactor.

  12. Effects of subchronic inhalation exposure of rats to emissions from a diesel engine burning soybean oil-derived biodiesel fuel.

    PubMed

    Finch, G L; Hobbs, C H; Blair, L F; Barr, E B; Hahn, F F; Jaramillo, R J; Kubatko, J E; March, T H; White, R K; Krone, J R; Ménache, M G; Nikula, K J; Mauderly, J L; Van Gerpen, J; Merceica, M D; Zielinska, B; Stankowski, L; Burling, K; Howell, S

    2002-10-01

    There is increasing interest in diesel fuels derived from plant oils or animal fats ("biodiesel"), but little information on the toxicity of biodiesel emissions other than bacterial mutagenicity. F344 rats were exposed by inhalation 6 h/day, 5 days/wk for 13 wk to 1 of 3 dilutions of emissions from a diesel engine burning 100% soybean oil-derived fuel, or to clean air as controls. Whole emissions were diluted to nominal NO(x) concentrations of 5, 25, or 50 ppm, corresponding to approximately 0.04, 0.2, and 0.5 mg particles/m(3), respectively. Biologically significant, exposure-related effects were limited to the lung, were greater in females than in males, and were observed primarily at the highest exposure level. There was a dose-related increase in the numbers of alveolar macrophages and the numbers of particles in the macrophages, as expected from repeated exposure, but no neutrophil response even at the highest exposure level. The macrophage response was reduced 28 days after cessation of the exposure. Among the high-level females, the group mean lung weight/body weight ratio was increased, and minimal, multifocal bronchiolar metaplasia of alveolar ducts was observed in 4 of 30 rats. Lung weights were not significantly increased, and metaplasia of the alveolar ducts was not observed in males. An increase in particle-laden macrophages was the only exposure-related finding in lungs at the intermediate and low levels, with fewer macrophages and fewer particles per macrophage at the low level. Alveolar histiocytosis was observed in a few rats in both exposed and control groups. There were statistically significant, but minor and not consistently exposure-related, differences in body weight, nonpulmonary organ weights, serum chemistry, and glial fibrillary acidic protein in the brain. There were no significant exposure-related effects on survival, clinical signs, feed consumption, ocular toxicity, hematology, neurohistology, micronuclei in bone marrow, sister

  13. Adaptation of Combustion Principles to Aircraft Propulsion. Volume I; Basic Considerations in the Combustion of Hydrocarbon Fuels with Air

    NASA Technical Reports Server (NTRS)

    Barnett, Henry C (Editor); Hibbard, Robert R (Editor)

    1955-01-01

    The report summarizes source material on combustion for flight-propulsion engineers. First, several chapters review fundamental processes such as fuel-air mixture preparation, gas flow and mixing, flammability and ignition, flame propagation in both homogenous and heterogenous media, flame stabilization, combustion oscillations, and smoke and carbon formation. The practical significance and the relation of these processes to theory are presented. A second series of chapters describes the observed performance and design problems of engine combustors of the principal types. An attempt is made to interpret performance in terms of the fundamental processes and theories previously reviewed. Third, the design of high-speed combustion systems is discussed. Combustor design principles that can be established from basic considerations and from experience with actual combustors are described. Finally, future requirements for aircraft engine combustion systems are examined.

  14. Effect of primary-zone water injection on pollutants from a combustor burning liquid ASTM A-1 and vaporized propane fuels

    NASA Technical Reports Server (NTRS)

    Ingebo, R. D.; Norgren, C. T.

    1973-01-01

    A combustor segment 0.457 meter (18 in.) long with a maximum cross section of 0.153 by 0.305 meter (6 by 12 in.) was operated at inlet-air temperatures of 590 and 700 K, inlet-air pressures of 4 and 10 atmospheres, and fuel-air ratios of 0.014 and 0.018 to determine the effect of primary-zone water injection on pollutants from burning either propane or ASTM A-1 fuel. At a simulated takeoff condition of 10 atmospheres and 700 K, multiple-orifice nozzles used to inject water at 1 percent of the airflow rate reduced nitrogen oxides 75 percent with propane and 65 percent with ASTM A-1 fuel. Although carbon monoxide and unburned hydrocarbons increased with water injection, they remained relatively low; and smoke numbers were well below the visibility limit.

  15. 49 CFR 175.310 - Transportation of flammable liquid fuel; aircraft only means of transportation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... or volcanic activity; or a declared state of emergency. The desire for expedience of a shipper... ventilation. (4) Each area or compartment in which the fuel is loaded is suitably ventilated to prevent...

  16. 49 CFR 175.310 - Transportation of flammable liquid fuel; aircraft only means of transportation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... or volcanic activity; or a declared state of emergency. The desire for expedience of a shipper... ventilation. (4) Each area or compartment in which the fuel is loaded is suitably ventilated to prevent...

  17. 49 CFR 175.310 - Transportation of flammable liquid fuel; aircraft only means of transportation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... or volcanic activity; or a declared state of emergency. The desire for expedience of a shipper... ventilation. (4) Each area or compartment in which the fuel is loaded is suitably ventilated to prevent...

  18. 49 CFR 175.310 - Transportation of flammable liquid fuel; aircraft only means of transportation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... or volcanic activity; or a declared state of emergency. The desire for expedience of a shipper... ventilation. (4) Each area or compartment in which the fuel is loaded is suitably ventilated to prevent...

  19. 49 CFR 175.310 - Transportation of flammable liquid fuel; aircraft only means of transportation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... or volcanic activity; or a declared state of emergency. The desire for expedience of a shipper... ventilation. (4) Each area or compartment in which the fuel is loaded is suitably ventilated to prevent...

  20. Reference energy-altitude descent guidance: Simulator evaluation. [aircraft descent and fuel conservation

    NASA Technical Reports Server (NTRS)

    Abbot, K. H.; Knox, C. E.

    1985-01-01

    Descent guidance was developed to provide a pilot with information to ake a fuel-conservative descent and cross a designated geographical waypoint at a preselected altitude and airspeed. The guidance was designed to reduce fuel usage during the descent and reduce the mental work load associated with planning a fuel-conservative descent. A piloted simulation was conducted to evaluate the operational use of this guidance concept. The results of the simulation tests show that the use of the guidance reduced fuel consumption and mental work load during the descent. Use of the guidance also decreased the airspeed error, but had no effect on the altitude error when the designated waypoint was crossed. Physical work load increased with the use of the guidance, but remained well within acceptable levels. The pilots found the guidance easy to use as presented and reported that it would be useful in an operational environment.

  1. Tankering Fuel on U.S. Air Force Transport Aircraft: An Assessment of Cost Savings

    DTIC Science & Technology

    2015-01-01

    software to determine whether their flights should tanker fuel to reduce operating costs. Since the Arabian oil embargo of 1973, air carriers have...Iraq and Afghanistan. The amounts of fuel that could potentially be tankered on these selected flights as well as the corresponding savings generated...possible need for compensation mechanisms within DoD as well as possible externalities that may result from an AMC tankering program. Our results

  2. Energy efficient engine: Propulsion system-aircraft integration evaluation

    NASA Technical Reports Server (NTRS)

    Owens, R. E.

    1979-01-01

    Flight performance and operating economics of future commercial transports utilizing the energy efficient engine were assessed as well as the probability of meeting NASA's goals for TSFC, DOC, noise, and emissions. Results of the initial propulsion systems aircraft integration evaluation presented include estimates of engine performance, predictions of fuel burns, operating costs of the flight propulsion system installed in seven selected advanced study commercial transports, estimates of noise and emissions, considerations of thrust growth, and the achievement-probability analysis.

  3. Aircraft Particle Emissions eXperiment (APEX)

    NASA Technical Reports Server (NTRS)

    Wey, C. C.; Anderson, B. E.; Hudgins, C.; Wey, C.; Li-Jones, X.; Winstead, E.; Thornhill, L. K.; Lobo, P.; Hagen, D.; Whitefield, P.

    2006-01-01

    APEX systematically investigated the gas-phase and particle emissions from a CFM56-2C1 engine on NASA's DC-8 aircraft as functions of engine power, fuel composition, and exhaust plumage. Emissions parameters were measured at 11 engine power, settings, ranging from idle to maximum thrust, in samples collected at 1, 10, and 30 m downstream of the exhaust plane as the aircraft burned three fuels to stress relevant chemistry. Gas-phase emission indices measured at 1 m were in good agreement with the ICAO data and predictions provided by GEAE empirical modeling tools. Soot particles emitted by the engine exhibited a log-normal size distribution peaked between 15 and 40 nm, depending on engine power. Samples collected 30 m downstream of the engine exhaust plane exhibited a prominent nucleation mode.

  4. Effect of increased fuel temperature on emissions of oxides of nitrogen from a gas turbine combustor burning ASTM jet-A fuel

    NASA Technical Reports Server (NTRS)

    Marchionna, N. R.

    1974-01-01

    An annular gas turbine combustor was tested with heated ASTM Jet-A fuel to determine the effect of increased fuel temperature on the formation of oxides of nitrogen. Fuel temperature ranged from ambient to 700 K. The NOx emission index increased at a rate of 6 percent per 100 K increase in fuel temperature.

  5. Study of effects of fuel properties in turbine-powered business aircraft

    NASA Technical Reports Server (NTRS)

    Powell, F. D.; Biegen, R. J.; Weitz, P. G., Jr.; Duke, A. M.

    1984-01-01

    Increased interest in research and technology concerning aviation turbine fuels and their properties was prompted by recent changes in the supply and demand situation of these fuels. The most obvious change is the rapid increase in fuel price. For commercial airplanes, fuel costs now approach 50 percent of the direct operating costs. In addition, there were occasional local supply disruptions and gradual shifts in delivered values of certain fuel properties. Dwindling petroleum reserves and the politically sensitive nature of the major world suppliers make the continuation of these trends likely. A summary of the principal findings, and conclusions are presented. Much of the material, especially the tables and graphs, is considered in greater detail later. The economic analysis and examination of operational considerations are described. Because some of the assumptions on which the economic analysis is founded are not easily verified, the sensitivity of the analysis to alternates for these assumptions is examined. The data base on which the analyses are founded is defined in a set of appendices.

  6. Study of effects of fuel properties in turbine-powered business aircraft. Final Report

    SciTech Connect

    Powell, F.D.; Biegen, R.J.; Weitz, P.G. Jr.; Duke, A.M.

    1984-04-01

    Increased interest in research and technology concerning aviation turbine fuels and their properties was prompted by recent changes in the supply and demand situation of these fuels. The most obvious change is the rapid increase in fuel price. For commercial airplanes, fuel costs now approach 50 percent of the direct operating costs. In addition, there were occasional local supply disruptions and gradual shifts in delivered values of certain fuel properties. Dwindling petroleum reserves and the politically sensitive nature of the major world suppliers make the continuation of these trends likely. A summary of the principal findings, and conclusions are presented. Much of the material, especially the tables and graphs, is considered in greater detail later. The economic analysis and examination of operational considerations are described. Because some of the assumptions on which the economic analysis is founded are not easily verified, the sensitivity of the analysis to alternates for these assumptions is examined. The data base on which the analyses are founded is defined in a set of appendices.

  7. Thermal stability of some aircraft turbine fuels derived from oil shale and coal

    NASA Technical Reports Server (NTRS)

    Reynolds, T. W.

    1977-01-01

    Thermal stability breakpoint temperatures are shown for 32 jet fuels prepared from oil shale and coal syncrudes by various degrees of hydrogenation. Low severity hydrotreated shale oils, with nitrogen contents of 0.1 to 0.24 weight percent, had breakpoint temperatures in the 477 to 505 K (400 to 450 F) range. Higher severity treatment, lowering nitrogen levels to 0.008 to 0.017 weight percent, resulted in breakpoint temperatures in the 505 to 533 K (450 to 500 F) range. Coal derived fuels showed generally increasing breakpoint temperatures with increasing weight percent hydrogen, fuels below 13 weight percent hydrogen having breakpoints below 533 K (500 F). Comparisons are shown with similar literature data.

  8. Potential Fuel Savings of Specific ATC System Improvements.

    DTIC Science & Technology

    1982-02-01

    the vv~ sftr statistics of measured or Predicted values Ad of expected Individual f light variability about assumed norms. a; In the-eveat of a...aircraft separation standards alone. Though some buffering to account for the uncertainties inherent in resolving competition for the use of the active...1981isows that: a. Air Carriers account for about 87% of the annual fuel burn, and nearly all of that is jet fuel. b. General Aviation accounts for the

  9. Integrated Control with Structural Feedback to Enable Lightweight Aircraft

    NASA Technical Reports Server (NTRS)

    Taylor, Brian R.

    2011-01-01

    This presentation for the Fundamental Aeronautics Program Technical Conference covers the benefits of active structural control, related research areas, and focuses on the use of optimal control allocation for the prevention of critical loads. Active control of lightweight structures has the potential to reduce aircraft weight and fuel burn. Sensor, control law, materials, control effector, and system level research will be necessary to enable active control of lightweight structures. Optimal control allocation with structural feedback has been shown in simulation to be feasible in preventing critical loads and is one example of a control law to enable future lightweight aircraft.

  10. Investigation of Electromagnetic Field Threat to Fuel Tank Wiring of a Transport Aircraft

    NASA Technical Reports Server (NTRS)

    Ely, Jay J.; Nguyen, Truong X.; Dudley, Kenneth L.; Scearce, Stephen A.; Beck, Fred B.; Deshpande, Manohar D.; Cockrell, C. R.

    2000-01-01

    National Transportation Safety Board investigators have questioned whether an electrical discharge in the Fuel Quantity Indication System (FQIS) may have initiated the TWA-800 center wing tank explosion. Because the FQIS was designed to be incapable of producing such a discharge on its own, attention has been directed to mechanisms of outside electromagnetic influence. To support the investigation, the NASA Langley Research Center was tasked to study the potential for radiated electromagnetic fields from external radio frequency (RF) transmitters and passenger carried portable electronic devices (PEDs) to excite the FQIS enough to cause arcing, sparking or excessive heating within the fuel tank.

  11. Input/output models for general aviation piston-prop aircraft fuel economy

    NASA Technical Reports Server (NTRS)

    Sweet, L. M.

    1982-01-01

    A fuel efficient cruise performance model for general aviation piston engine airplane was tested. The following equations were made: (1) for the standard atmosphere; (2) airframe-propeller-atmosphere cruise performance; and (3) naturally aspirated engine cruise performance. Adjustments are made to the compact cruise performance model as follows: corrected quantities, corrected performance plots, algebraic equations, maximize R with or without constraints, and appears suitable for airborne microprocessor implementation. The following hardwares are recommended: ignition timing regulator, fuel-air mass ration controller, microprocessor, sensors and displays.

  12. Particulate hydroxy-PAH emissions from a residential wood log stove using different fuels and burning conditions

    NASA Astrophysics Data System (ADS)

    Avagyan, Rozanna; Nyström, Robin; Lindgren, Robert; Boman, Christoffer; Westerholm, Roger

    2016-09-01

    Hydroxylated polycyclic aromatic hydrocarbons are oxidation products of polycyclic aromatic hydrocarbons, but have not been studied as extensively as polycyclic aromatic hydrocarbons. Several studies have however shown that hydroxylated polycyclic aromatic hydrocarbons have toxic and carcinogenic properties. They have been detected in air samples in semi urban areas and combustion is assumed to be the primary source of those compounds. To better understand the formation and occurrence of particulate hydroxylated polycyclic aromatic hydrocarbons from residential wood log stove combustion, 9 hydroxylated polycyclic aromatic hydrocarbons and 2 hydroxy biphenyls were quantified in particles generated from four different types of wood logs (birch, spruce, pine, aspen) and two different combustion conditions (nominal and high burn rate). A previously developed method utilizing liquid chromatography - photo ionization tandem mass spectrometry and pressurized liquid extraction was used. Polycyclic aromatic hydrocarbons were analyzed along with hydroxylated polycyclic aromatic hydrocarbons. The hydroxylated polycyclic aromatic hydrocarbon emissions varied significantly across different wood types and burning conditions; the highest emissions for nominal burn rate were from spruce and for high burn rate from pine burning. Emissions from nominal burn rate corresponded on average to 15% of the emissions from high burn rate, with average emissions of 218 μg/MJfuel and 32.5 μg/MJfuel for high burn rate and nominal burn rate, respectively. Emissions of the measured hydroxylated polycyclic aromatic hydrocarbons corresponded on average to 28% of polycyclic aromatic hydrocarbons emissions. This study shows that wood combustion is a large emission source of hydroxylated polycyclic aromatic hydrocarbons and that not only combustion conditions, but also wood type influences the emissions of hydroxylated polycyclic aromatic hydrocarbons and polycyclic aromatic hydrocarbons. There are

  13. Probing Aircraft Flight Test Hazard Mitigation for the Alternative Fuel Effects on Contrails and Cruise Emissions (ACCESS) Research Team . Volume 2; Appendices

    NASA Technical Reports Server (NTRS)

    Kelly, Michael J.

    2013-01-01

    The Alternative Fuel Effects on Contrails and Cruise Emissions (ACCESS) Project Integration Manager requested in July 2012 that the NASA Engineering and Safety Center (NESC) form a team to independently assess aircraft structural failure hazards associated with the ACCESS experiment and to identify potential flight test hazard mitigations to ensure flight safety. The ACCESS Project Integration Manager subsequently requested that the assessment scope be focused predominantly on structural failure risks to the aircraft empennage (horizontal and vertical tail). This report contains the Appendices to Volume I.

  14. Measurements of the Fuel Mileage of a KC-135 Aircraft with and Without Winglets

    NASA Technical Reports Server (NTRS)

    Temanson, G. E.

    1982-01-01

    The KC-135A Winglet Flight Research and Demonstration Program was a joint effort of the Air Force, NASA and the Boeing Military Airplane Company to flight test winglets on the KC-135A. The primary objective of the program was to verify the cruise performance improvements predicted by analysis and wind tunnel tests. Flight test data were obtained for winglets positioned at 15 deg cant/-2 deg incidence, 0 deg cant/-4 deg incidence, 15 deg cant/-4 deg incidence and for winglets off (baseline). Both fuel mileage and drag measurements were obtained. The 15 deg cant/-4 deg incidence winglet configuration provided the greatest performance improvement. The flight test measured fuel mileage improvement for a 0.78 Mach number was 3.1 percent at 8 x 10(5) pounds W/delta and 5.5 percent at 1.05 x 10(6) pounds W/delta. Correcting the flight measured data for surface pressure differences between wind tunnel and flight resulted in a fuel mileage improvement of 4.4 percent at 8 x 10(5) pounds W/delta and 7.2 percent at 1.05 x 10(6) pounds W/delta. The agreement between the fuel mileage and drag data was excellent.

  15. Variability of Major Organic Components in Aircraft Fuels. Volume 1. Technical Discussion

    DTIC Science & Technology

    1984-06-27

    yield an unequi- vocal definition of a GC/FID or GC/MS feature due to mass spectra similarities. TQ better define GC/FID and GC/MS features, additional...Reference Fuel. In this GC/MS quntitative analy- sis, each of the GC/FID features above 4 mg/ml was identifie using retention time and up to three

  16. Deep Burn: Development of Transuranic Fuel for High-Temperature Helium-Cooled Reactors- Monthly Highlights October 2010

    SciTech Connect

    Snead, Lance Lewis; Besmann, Theodore M; Collins, Emory D; Bell, Gary L

    2010-11-01

    The DB Program monthly highlights report for September 2010, ORNL/TM-2010/252, was distributed to program participants by email on October 26. This report discusses: (1) Core and Fuel Analysis; (2) Spent Fuel Management; (3) Fuel Cycle Integration of the HTR (high temperature helium-cooled reactor); (4) TRU (transuranic elements) HTR Fuel Qualification; (5) HTR Spent Fuel Recycle - (a) TRU Kernel Development (ORNL), (b) Coating Development (ORNL), (c) Characterization Development and Support, (d) ZrC Properties and Handbook; and (6) HTR Fuel Recycle.

  17. Performance modeling of Deep Burn TRISO fuel using ZrC as a load-bearing layer and an oxygen getter

    NASA Astrophysics Data System (ADS)

    Wongsawaeng, Doonyapong

    2010-01-01

    The effects of design choices for the TRISO particle fuel were explored in order to determine their contribution to attaining high-burnup in Deep Burn modular helium reactor fuels containing transuranics from light water reactor spent fuel. The new design features were: (1) ZrC coating substituted for the SiC, allowing the fuel to survive higher accident temperatures; (2) pyrocarbon/SiC "alloy" substituted for the inner pyrocarbon coating to reduce layer failure and (3) pyrocarbon seal coat and thin ZrC oxygen getter coating on the kernel to eliminate CO. Fuel performance was evaluated using General Atomics Company's PISA code. The only acceptable design has a 200-μm kernel diameter coupled with at least 150-μm thick, 50% porosity buffer, a 15-μm ZrC getter over a 10-μm pyrocarbon seal coat on the kernel, an alloy inner pyrocarbon, and ZrC substituted for SiC. The code predicted that during a 1600 °C postulated accident at 70% FIMA, the ZrC failure probability is <10-4.

  18. Cryogenic system options for a superconducting aircraft propulsion system

    NASA Astrophysics Data System (ADS)

    Berg, F.; Palmer, J.; Bertola, L.; Miller, Paul; Dodds, Graham

    2015-12-01

    There is a perceived need in the future for a move away from traditional aircraft designs in order to meet ambitious emissions and fuel burn targets. High temperature superconducting distributed propulsion may be an enabler for aircraft designs that have better propulsive efficiency and lower drag. There has been significant work considering the electrical systems required, but less on the cryogenics to enable it. This paper discusses some of the major choices to be faced in cryocooling for aircraft. The likely need for a disposable cryogen to reduce power demand is explained. A set of cryocooling methods are considered in a sensitivity study, which shows that the feasibility of the cryogenic system will depend strongly on the superconducting technology and the aircraft platform. It is argued that all three aspects must be researched and designed in close collaboration to reach a viable solution.

  19. Impact of Airspace Charges on Transatlantic Aircraft Trajectories

    NASA Technical Reports Server (NTRS)

    Sridhar, Banavar; Ng, Hok K.; Linke, Florian; Chen, Neil Y.

    2015-01-01

    Aircraft flying over the airspace of different countries are subject to over-flight charges. These charges vary from country to country. Airspace charges, while necessary to support the communication, navigation and surveillance services, may lead to aircraft flying routes longer than wind-optimal routes and produce additional carbon dioxide and other gaseous emissions. This paper develops an optimal route between city pairs by modifying the cost function to include an airspace cost whenever an aircraft flies through a controlled airspace without landing or departing from that airspace. It is assumed that the aircraft will fly the trajectory at a constant cruise altitude and constant speed. The computationally efficient optimal trajectory is derived by solving a non-linear optimal control problem. The operational strategies investigated in this study for minimizing aircraft fuel burn and emissions include flying fuel-optimal routes and flying cost-optimal routes that may completely or partially reduce airspace charges en route. The results in this paper use traffic data for transatlantic flights during July 2012. The mean daily savings in over-flight charges, fuel cost and total operation cost during the period are 17.6 percent, 1.6 percent, and 2.4 percent respectively, along the cost- optimal trajectories. The transatlantic flights can potentially save $600,000 in fuel cost plus $360,000 in over-flight charges daily by flying the cost-optimal trajectories. In addition, the aircraft emissions can be potentially reduced by 2,070 metric tons each day. The airport pairs and airspace regions that have the highest potential impacts due to airspace charges are identified for possible reduction of fuel burn and aircraft emissions for the transatlantic flights. The results in the paper show that the impact of the variation in fuel price on the optimal routes is to reduce the difference between wind-optimal and cost-optimal routes as the fuel price increases. The

  20. Study of flame quenching and near-wall combustion of lean burn fuel-air mixture in a catalytically activated spark-ignited lean burn engine

    SciTech Connect

    Nedunchezhian, N.; Dhandapani, S.

    2006-01-01

    A study of the catalytic activation of charge near the combustion chamber wall and of the flame quenching phenomenon was carried out to identify whether flame quenches due to catalytic activation or due to thermal quenching. It was found that (1) the diffusion rate of fuel into the boundary sublayer limits the catalytic surface reaction rate during combustion; (2) the results of the present flame quench model indicate that the flame quenches due to the heat loss to walls, and the depletion of fuel due to the catalyst coated on the combustion chamber walls does not affect flame quenching; (3) the catalysts coated on the combustion chamber surface do not contribute increased hydrocarbon emissions, but actually reduce them; (4) each catalyst has a specific surface temperature, at which the Damkoehler number for surface reaction is unity.

  1. The effects of aircraft fuel and fluids on the strength properties of Resin Transfer Molded (RTM) composites

    NASA Technical Reports Server (NTRS)

    Falcone, Anthony; Dow, Marvin B.

    1993-01-01

    The resin transfer molding (RTM) process offers important advantages for cost-effective composites manufacturing, and consequently has become the subject of intense research and development efforts. Several new matrix resins have been formulated specifically for RTM applications in aircraft and aerospace vehicles. For successful use on aircraft, composite materials must withstand exposure to the fluids in common use. The present study was conducted to obtain comparative screening data on several state-ofthe-art RTM resins after environmental exposures were performed on RTM composite specimens. Four graphite/epoxy composites and one graphite/bismaleimide composite were tested; testing of two additional graphite epoxy composites is in progress. Zero-deg tension tests were conducted on specimens machined from eight-ply (+45-deg, -45-deg) laminates, and interlaminar shear tests were conducted on 32-ply 0-deg laminate specimens. In these tests, the various RTM resins demonstrated widely different strengths, with 3501-6 epoxy being the strongest. As expected, all of the matrix resins suffered severe strength degradation from exposure to methylene chloride (paint stripper). The 3501-6 epoxy composites exhibited about a 30 percent drop in tensile strength in hot, wet tests. The E905-L epoxy exhibited little loss of tensile strength (less than 8 percent) after exposure to water. The CET-2 and 862 epoxies as well as the bismaleimide exhibited reduced strengths at elevated temperature after exposure to oils and fuel. In terms of the percentage strength reductions, all of the RTM matrix resins compared favorably with 3501-6 epoxy.

  2. Engine fuels and lubrication systems at Nakajima Aircraft Co. from 1936-1945

    SciTech Connect

    Nakagawa, R.; Mizutani, S

    1988-01-01

    From 1941 on, all newly designed engines had to use 87-92 motor octane fuel by order of the Army and Navy. It was a very difficult task to change the engine specifications to meet this requirement, particularly for the Homare engine, which was initially designed for 100-octane fuel. The authors explain various steps taken to overcome this difficulty. As for lubricants, the main lubricant changed from castor oil to mineral oil after 1937. The Homare engine design program got under way soon after that. The lubrication system design proved to be one of the most difficult problems, and a total lubrication system was planned from the beginning. At the development stage, various difficulties were encountered, including problems with the main connecting rod bearing metal.

  3. Insulation systems for liquid methane fuel tanks for supersonic cruise aircraft

    NASA Technical Reports Server (NTRS)

    Brady, H. F.; Delduca, D.

    1972-01-01

    Two insulation systems for tanks containing liquid methane in supersonic cruise-type aircraft were designed and tested after an extensive materials investigation. One system is an external insulation and the other is an internal wet-type insulation system. Tank volume was maximized by making the tank shape approach a rectangular parallelopiped. One tank was designed to use the external insulation and the other tank to use the internal insulation. Performance of the external insulation system was evaluated on a full-scale tank under the temperature environment of -320 F to 700 F and ambient pressures of ground-level atmospheric to 1 psia. Problems with installing the internal insulation on the test tank prevented full-scale evaluation of performance; however, small-scale testing verified thermal conductivity, temperature capability, and installed density.

  4. Biofuel blending reduces particle emissions from aircraft engines at cruise conditions

    NASA Astrophysics Data System (ADS)

    Moore, Richard H.; Thornhill, Kenneth L.; Weinzierl, Bernadett; Sauer, Daniel; D’Ascoli, Eugenio; Kim, Jin; Lichtenstern, Michael; Scheibe, Monika; Beaton, Brian; Beyersdorf, Andreas J.; Barrick, John; Bulzan, Dan; Corr, Chelsea A.; Crosbie, Ewan; Jurkat, Tina; Martin, Robert; Riddick, Dean; Shook, Michael; Slover, Gregory; Voigt, Christiane; White, Robert; Winstead, Edward; Yasky, Richard; Ziemba, Luke D.; Brown, Anthony; Schlager, Hans; Anderson, Bruce E.

    2017-03-01

    Aviation-related aerosol emissions contribute to the formation of contrail cirrus clouds that can alter upper tropospheric radiation and water budgets, and therefore climate. The magnitude of air-traffic-related aerosol–cloud interactions and the ways in which these interactions might change in the future remain uncertain. Modelling studies of the present and future effects of aviation on climate require detailed information about the number of aerosol particles emitted per kilogram of fuel burned and the microphysical properties of those aerosols that are relevant for cloud formation. However, previous observational data at cruise altitudes are sparse for engines burning conventional fuels, and no data have previously been reported for biofuel use in-flight. Here we report observations from research aircraft that sampled the exhaust of engines onboard a NASA DC-8 aircraft as they burned conventional Jet A fuel and a 50:50 (by volume) blend of Jet A fuel and a biofuel derived from Camelina oil. We show that, compared to using conventional fuels, biofuel blending reduces particle number and mass emissions immediately behind the aircraft by 50 to 70 per cent. Our observations quantify the impact of biofuel blending on aerosol emissions at cruise conditions and provide key microphysical parameters, which will be useful to assess the potential of biofuel use in aviation as a viable strategy to mitigate climate change.

  5. Biofuel blending reduces particle emissions from aircraft engines at cruise conditions.

    PubMed

    Moore, Richard H; Thornhill, Kenneth L; Weinzierl, Bernadett; Sauer, Daniel; D'Ascoli, Eugenio; Kim, Jin; Lichtenstern, Michael; Scheibe, Monika; Beaton, Brian; Beyersdorf, Andreas J; Barrick, John; Bulzan, Dan; Corr, Chelsea A; Crosbie, Ewan; Jurkat, Tina; Martin, Robert; Riddick, Dean; Shook, Michael; Slover, Gregory; Voigt, Christiane; White, Robert; Winstead, Edward; Yasky, Richard; Ziemba, Luke D; Brown, Anthony; Schlager, Hans; Anderson, Bruce E

    2017-03-15

    Aviation-related aerosol emissions contribute to the formation of contrail cirrus clouds that can alter upper tropospheric radiation and water budgets, and therefore climate. The magnitude of air-traffic-related aerosol-cloud interactions and the ways in which these interactions might change in the future remain uncertain. Modelling studies of the present and future effects of aviation on climate require detailed information about the number of aerosol particles emitted per kilogram of fuel burned and the microphysical properties of those aerosols that are relevant for cloud formation. However, previous observational data at cruise altitudes are sparse for engines burning conventional fuels, and no data have previously been reported for biofuel use in-flight. Here we report observations from research aircraft that sampled the exhaust of engines onboard a NASA DC-8 aircraft as they burned conventional Jet A fuel and a 50:50 (by volume) blend of Jet A fuel and a biofuel derived from Camelina oil. We show that, compared to using conventional fuels, biofuel blending reduces particle number and mass emissions immediately behind the aircraft by 50 to 70 per cent. Our observations quantify the impact of biofuel blending on aerosol emissions at cruise conditions and provide key microphysical parameters, which will be useful to assess the potential of biofuel use in aviation as a viable strategy to mitigate climate change.

  6. Development of Fuel Neutralizing Agents to Prevent Flashback on Aircraft Fires

    DTIC Science & Technology

    1991-05-01

    polyvinyi pyrrolidone (PVP), polyacrylamide (PAM) or ■carboxymethylcellulose (CMC). 4. ü.015-0.05% starch polyacrylonitrile graft copolymer...Flowing Toup.h Film/Foam Addition of a starch grafted copolymer to a mixture of aqueous film- forming and protein-containing fluorosurfactant foams...Fuel Number U Milliliter Polyacrylamide Propylene Glycol Polyvinyl Pyrolidine Sticky Water xv i SECTION I INTRODUCTION A. OBJECTIVE The

  7. Estimates of global, regional, and national annual CO{sub 2} emissions from fossil-fuel burning, hydraulic cement production, and gas flaring: 1950--1992

    SciTech Connect

    Boden, T.A.; Marland, G.; Andres, R.J.

    1995-12-01

    This document describes the compilation, content, and format of the most comprehensive C0{sub 2}-emissions database currently available. The database includes global, regional, and national annual estimates of C0{sub 2} emissions resulting from fossil-fuel burning, cement manufacturing, and gas flaring in oil fields for 1950--92 as well as the energy production, consumption, and trade data used for these estimates. The methods of Marland and Rotty (1983) are used to calculate these emission estimates. For the first time, the methods and data used to calculate CO, emissions from gas flaring are presented. This C0{sub 2}-emissions database is useful for carbon-cycle research, provides estimates of the rate at which fossil-fuel combustion has released C0{sub 2} to the atmosphere, and offers baseline estimates for those countries compiling 1990 C0{sub 2}-emissions inventories.

  8. Landing on empty: estimating the benefits from reducing fuel uplift in US Civil Aviation

    NASA Astrophysics Data System (ADS)

    Ryerson, Megan S.; Hansen, Mark; Hao, Lu; Seelhorst, Michael

    2015-09-01

    Airlines and Air Navigation Service Providers are united in their goal to reduce fuel consumption. While changes to flight operations and technology investments are the focus of a number of studies, our study is among the first to investigate an untapped source of aviation fuel consumption: excess contingency fuel loading. Given the downside risk of fuel exhaustion of diverting to an alternate airport, airline dispatchers may load excess fuel onto an aircraft. Such conservatism comes at a cost of consuming excess fuel, as fuel consumed is a function of, among other factors, aircraft weight. The aim of this paper is to quantify, on a per-flight basis, the fuel burned due to carrying fuel beyond what is needed for foreseeable contingencies, and thereby motivate research, federal guidance, and investments that allow airline dispatchers to reduce fuel uplift while maintaining near zero risks of fuel exhaustion. We merge large publicly available aviation and weather databases with a detailed dataset from a major US airline. Upon estimating factors that capture the quantity fuel consumed due to carrying a pound of weight for a range of aircraft types, we calculate the cost and greenhouse gas emissions from carrying unused fuel on arrival and additional contingency fuel above a conservative buffer for foreseeable contingencies. We establish that the major US carrier does indeed load fuel conservatively. We find that 4.48% of the fuel consumed by an average flight is due to carrying unused fuel and 1.04% of the fuel consumed by an average flight is due to carrying additional contingency fuel above a reasonable buffer. We find that simple changes in flight dispatching that maintain a statistically minimal risk of fuel exhaustion could result in yearly savings of 338 million lbs of CO2, the equivalent to the fuel consumed from 4760 flights on midsized commercial aircraft. Moreover, policy changes regarding maximum fuel loads or investments that reduce uncertainty or increase

  9. NASA Alternative Aviation Fuel Research

    NASA Astrophysics Data System (ADS)

    Anderson, B. E.; Beyersdorf, A. J.; Thornhill, K. L., II; Moore, R.; Shook, M.; Winstead, E.; Ziemba, L. D.; Crumeyrolle, S.

    2015-12-01

    We present an overview of research conducted by NASA Aeronautics Research Mission Directorate to evaluate the performance and emissions of "drop-in" alternative jet fuels, highlighting experiment design and results from the Alternative Aviation Fuel Experiments (AAFEX-I & -II) and Alternative Fuel-Effects on Contrails and Cruise Emissions flight series (ACCESS-I & II). These projects included almost 100 hours of sampling exhaust emissions from the NASA DC-8 aircraft in both ground and airborne operation and at idle to takeoff thrust settings. Tested fuels included Fischer-Tropsch (FT) synthetic kerosenes manufactured from coal and natural-gas feedstocks; Hydro-treated Esters and Fatty-Acids (HEFA) fuels made from beef-tallow and camelina-plant oil; and 50:50 blends of these alternative fuels with Jet A. Experiments were also conducted with FT and Jet A fuels doped with tetrahydrothiophene to examine the effects of fuel sulfur on volatile aerosol and contrail formation and microphysical properties. Results indicate that although the absence of aromatic compounds in the alternative fuels caused DC-8 fuel-system leaks, the fuels did not compromise engine performance or combustion efficiency. And whereas the alternative fuels produced only slightly different gas-phase emissions, dramatic reductions in non-volatile particulate matter (nvPM) emissions were observed when burning the pure alternative fuels, particularly at low thrust settings where particle number and mass emissions were an order of magnitude lower than measured from standard jet fuel combustion; 50:50 blends of Jet A and alternative fuels typically reduced nvPM emissions by ~50% across all thrust settings. Alternative fuels with the highest hydrogen content produced the greatest nvPM reductions. For Jet A and fuel blends, nvPM emissions were positively correlated with fuel aromatic and naphthalene content. Fuel sulfur content regulated nucleation mode aerosol number and mass concentrations within aging

  10. Materials Aspects of Turboelectric Aircraft Propulsion

    NASA Technical Reports Server (NTRS)

    Brown, Gerald V.

    2009-01-01

    The turboelectric distributed propulsion approach for aircraft makes a contribution to all four "corners" of NASA s Subsonic Fixed Wing trade space, reducing fuel burn, noise, emissions and field length. To achieve the system performance required for the turboelectric approach, a number of advances in materials and structures must occur. These range from improved superconducting composites to structural composites for support windings in superconducting motors at cryogenic temperatures. The rationale for turboelectric distributed propulsion and the materials research and development opportunities that it may offer are outlined.

  11. Ignition of Fuel Vapors Beneath Titanium Aircraft Skins Exposed to Lightning

    NASA Technical Reports Server (NTRS)

    Kosvic, T. C.; Helgeson, N. L.; Gerstein, M.

    1971-01-01

    Hot-spot and puncture ignition of fuel vapors by simulated lightning discharges was studied experimentally. The influences of skin coating, skin structure, discharge polarity, skin thickness, discharge current level, and current duration were measured and interpreted. Ignition thresholds are reported for titanium alloy constructed as sheets, sheets coated with sealants, and sandwich skins. Results indicated that the ignition threshold charge transfer for coated sheets, honeycomb, and truss skins is respectively about 200%, 400%, 800% that of bare alloy sheet of .102 cm (.040 in.)-thickness. It was found that hot-spot ignition can occur well after termination of the arc, and that sandwich materials allow ignition only if punctured.

  12. An effective and practical fire-protection system. [for aircraft fuel storage and transport

    NASA Technical Reports Server (NTRS)

    Mansfield, J. A.; Riccitiello, S. R.; Fewell, L. L.

    1975-01-01

    A high-performance sandwich-type fire protection system comprising a steel outer sheath and insulation combined in various configurations is described. An inherent advantage of the sheath system over coatings is that it eliminates problems of weatherability, materials strength, adhesion, and chemical attack. An experimental comparison between the protection performance of state-of-the-art coatings and the sheath system is presented, with emphasis on the protection of certain types of steel tanks for fuel storage and transport. Sheath systems are thought to be more expensive than coatings in initial implementation, although they are less expensive per year for sufficiently long applications.

  13. First direct sulfuric acid detection in the exhaust plume of a jet aircraft in flight

    NASA Astrophysics Data System (ADS)

    Curtius, J.; Sierau, B.; Arnold, F.; Baumann, R.; Busen, R.; Schulte, P.; Schumann, U.

    Sulfuric acid (SA) was for the first time directly detected in the exhaust plume of a jet aircraft in flight. The measurements were made by a novel aircraft-based VACA (Volatile Aerosol Component Analyzer) instrument of MPI-K Heidelberg while the research aircraft Falcon was chasing another research aircraft ATTAS. The VACA measures the total SA in the gas and in volatile submicron aerosol particles. During the chase the engines of the ATTAS alternatively burned sulfur-poor and sulfur-rich fuel. In the sulfur-rich plume very marked enhancements of total SA were observed of up to 1300 pptv which were closely correlated with ΔCO2 and ΔT and were far above the local ambient atmospheric background-level of typically 15-50 pptv. Our observations indicate a lower limit for the efficiency ɛ for fuel-sulfur conversion to SA of 0.34 %.

  14. Single-Lever Power Control for General Aviation Aircraft Promises Improved Efficiency and Simplified Pilot Controls

    NASA Technical Reports Server (NTRS)

    Musgrave, Jeffrey L.

    1997-01-01

    General aviation research is leading to major advances in internal combustion engine control systems for single-engine, single-pilot aircraft. These advances promise to increase engine performance and fuel efficiency while substantially reducing pilot workload and increasing flight safety. One such advance is a single-lever power control (SLPC) system, a welcome departure from older, less user-friendly, multilever engine control systems. The benefits of using single-lever power controls for general aviation aircraft are improved flight safety through advanced engine diagnostics, simplified powerplant operations, increased time between overhauls, and cost-effective technology (extends fuel burn and reduces overhaul costs). The single-lever concept has proven to be so effective in preliminary studies that general aviation manufacturers are making plans to retrofit current aircraft with the technology and are incorporating it in designs for future aircraft.

  15. Study for the optimization of a transport aircraft wing for maximum fuel efficiency. Volume 1: Methodology, criteria, aeroelastic model definition and results

    NASA Technical Reports Server (NTRS)

    Radovcich, N. A.; Dreim, D.; Okeefe, D. A.; Linner, L.; Pathak, S. K.; Reaser, J. S.; Richardson, D.; Sweers, J.; Conner, F.

    1985-01-01

    Work performed in the design of a transport aircraft wing for maximum fuel efficiency is documented with emphasis on design criteria, design methodology, and three design configurations. The design database includes complete finite element model description, sizing data, geometry data, loads data, and inertial data. A design process which satisfies the economics and practical aspects of a real design is illustrated. The cooperative study relationship between the contractor and NASA during the course of the contract is also discussed.

  16. Methodology of Fuel Burn Up Fitting in VVER-1000 Reactor Core by Using New Ex-Vessel Neutron Dosimetry and In-Core Measurements and its Application for Routine Reactor Pressure Vessel Fluence Calculations

    NASA Astrophysics Data System (ADS)

    Borodkin, Pavel; Borodkin, Gennady; Khrennikov, Nikolay

    2016-02-01

    Paper describes the new approach of fitting axial fuel burn-up patterns in peripheral fuel assemblies of VVER-1000 type reactors, on the base of ex-core neutron leakage measurements, neutron-physical calculations and in-core SPND measured data. The developed approach uses results of new ex-vessel measurements on different power units through different reactor cycles and their uncertainties to clear the influence of a fitted fuel burn-up profile to the RPV neutron fluence calculations. The new methodology may be recommended to be included in the routine fluence calculations used in RPV lifetime management and may be taken into account during VVER-1000 core burn-up pattern correction.

  17. An Evaluation of Performance Metrics for High Efficiency Tube-and-Wing Aircraft Entering Service in 2030 to 2035

    NASA Technical Reports Server (NTRS)

    Perkins, H. Douglas; Wilson, Jack; Raymer, Daniel P.

    2011-01-01

    An analysis of basic vehicle characteristics required to meet the Fundamental Aeronautics Program s 70 percent energy consumption reduction goal for commercial airliners in the 2030 to 2035 timeframe was conducted. A total of 29 combinations of vehicle parasitic drag coefficient, vehicle induced drag coefficient, vehicle empty weight and engine Specific Fuel Consumption were used to create sized tube-and-wing vehicle models. The mission fuel burn for each of these sized vehicles was then compared to a baseline current technology vehicle. A response surface equation was generated of fuel burn reduction as a function of the four basic vehicle performance metrics, so that any values of the performance metrics up to a 50 percent reduction could be used to estimate fuel burn reduction of tube-and-wing aircraft for future studies.

  18. Cross-Polar Aircraft Trajectory Optimization and Potential Climate Impact

    NASA Technical Reports Server (NTRS)

    Sridhar, Banavar; Chen, Neil; Ng, Hok

    2011-01-01

    Cross-Polar routes offer new opportunities for air travel markets. Transpolar flights reduce travel times, fuel burns, and associated environmental emissions by flying direct paths between many North American and Asian cities. This study evaluates the potential benefits of flying wind-optimal polar routes and assessed their potential impact on climate change. An optimization algorithm is developed for transpolar flights to generate wind-optimal trajectories that minimize climate impact of aircraft, in terms of global warming potentials (relative to warming by one kg of CO2) of several types of emissions, while avoiding regions of airspace that facilitate persistent contrail formation. Estimations of global warming potential are incorporated into the objective function of the optimization algorithm to assess the climate impact of aircraft emissions discharged at a given location and altitude. The regions of airspace with very low ambient temperature and areas favorable to persistent contrail formation are modeled as undesirable regions that aircraft should avoid and are formulated as soft state constraints. The fuel burn and climate impact of cross-polar air traffic flying various types of trajectory including flightplan, great circle, wind-optimal, and contrail-avoidance are computed for 15 origin-destination pairs between major international airports in the U.S. and Asia. Wind-optimal routes reduce average fuel burn of flight plan routes by 4.4% on December 4, 2010 and 8.0% on August 7, 2010, respectively. The tradeoff between persistent contrail formation and additional global warming potential of aircraft emissions is investigated with and without altitude optimization. Without altitude optimization, the reduction in contrail travel times is gradual with increase in total fuel consumption. When altitude is optimized, a one percent increase in additional global warming potential, a climate impact equivalent to that of 4070kg and 4220kg CO2 emission, reduces 135

  19. Statistical approaches for identifying air pollutant mixtures associated with aircraft departures at Los Angeles International Airport.

    PubMed

    Diez, David M; Dominici, Francesca; Zarubiak, Darcy; Levy, Jonathan I

    2012-08-07

    Aircraft departures emit multiple pollutants common to other near-airport sources, making it challenging to determine relative source contributions. While there may not be unique tracers of aircraft emissions, examination of multipollutant concentration patterns in combination with flight activity can facilitate source attribution. In this study, we examine concentrations of continuously monitored air pollutants measured in 2008 near a departure runway at Los Angeles International Airport (LAX), considering single-pollutant associations with landing and takeoff (LTO) of the aircraft (LTO activity, weighted by LTO cycle fuel burn), as well as multipollutant predictors of binary LTO activity. In the single-pollutant analyses, one-minute average concentrations of carbon monoxide, carbon dioxide, nitrogen oxides, and sulfur dioxide are positively associated with fuel burn-weighted departures on the runway proximate to the monitor, whereas ozone is negatively associated with fuel burn-weighted departures. In analyses in which the flight departure is predicted by pollutant concentrations, carbon dioxide and nitrogen oxides are the best individual predictors, but including all five pollutants greatly increases the power of prediction compared to single-pollutant models. Our results demonstrate that air pollution impacts from aircraft departures can be isolated using time-resolved monitoring data, and that combinations of simultaneously measured pollutants can best identify contributions from flight activity.

  20. Parametric Analyses of Potential Effects on Upper Tropospheric/Lower Stratospheric Ozone Chemistry by a Future Fleet of High Speed Civil Transport (HSCT) Type Aircraft

    NASA Technical Reports Server (NTRS)

    Dutta, Mayurakshi; Patten, Kenneth O.; Wuebbles,Donald J.

    2005-01-01

    This report analyzed the potential impact of projected fleets of HSCT aircraft (currently not under development) through a series of parametric analyses that examine the envelope of potential effects on ozone over a range of total fuel burns, emission indices of nitrogen oxides, and cruise altitudes.

  1. Alternate-Fueled Combustion-Sector Emissions

    NASA Technical Reports Server (NTRS)

    Saxena, Nikita T.; Thomas, Anna E.; Shouse, Dale T.; Neuroth, Craig; Hendricks, Robert C.; Lynch, Amy; Frayne, Charles W.; Stutrud, Jeffrey S.; Corporan, Edwin; Hankins, Terry

    2012-01-01

    In order to meet rapidly growing demand for fuel, as well as address environmental concerns, the aviation industry has been testing alternate fuels for performance and technical usability in commercial and military aircraft. Currently, alternate aviation fuels must satisfy MIL-DTL- 83133F(2008) (military) or ASTM D 7566- Annex(2011) (commercial) standards and are termed drop-in fuel replacements. Fuel blends of up to 50% alternative fuel blended with petroleum (JP-8), which have become a practical alternative, are individually certified on the market. In order to make alternate fuels (and blends) a viable option for aviation, the fuel must be able to perform at a similar or higher level than traditional petroleum fuel. They also attempt to curb harmful emissions, and therefore a truly effective alternate fuel would emit at or under the level of currently used fuel. This paper analyzes data from gaseous and particulate emissions of an aircraft combustor sector. The data were evaluated at various inlet conditions, including variation in pressure and temperature, fuel-to-air ratios, and percent composition of alternate fuel. Traditional JP-8+100 data were taken as a baseline, and blends of JP- 8+100 with synthetic-paraffinic-kerosene (SPK) fuel (Fischer-Tropsch (FT)) were used for comparison. Gaseous and particulate emissions, as well as flame luminosity, were assessed for differences between FT composition of 0%, 50%, and 100%. The data showed that SPK fuel (a FT-derived fuel) had slightly lower harmful gaseous emissions, and smoke number information corroborated the hypothesis that SPK-FT fuels are cleaner burning fuels.

  2. Reductions in Emissions of Carbonaceous Particulate Matter and Polycyclic Aromatic Hydrocarbons from Combustion of Biomass Pellets in Comparisonwith Raw Fuel Burning

    PubMed Central

    SHEN, Guofeng; TAO, Shu; WEI, Siye; ZHANG, Yanyan; WANG, Rong; WANG, Bin; LI, Wei; SHEN, Huizhong; HUANG, Ye; CHEN, Yuanchen; CHEN, Han; YANG, Yifeng; WANG, Wei; WEI, Wen; WANG, Xilong; LIU, Wenxing; WANG, Xuejun; SIMONICH, Staci L. Massey

    2012-01-01

    Biomass pellets are emerging as a cleaner alternative to traditional biomass fuels. The potential benefits of using biomass pellets include improving energy utilization efficiency and reducing emissions of air pollutants. To assess the environmental, climate, and health significance of replacing traditional fuels with biomass pellets, it is critical to measure the emission factors (EFs) of various pollutants from pellet burning. However, only a few field measurements have been conducted on the emissions of carbon monoxide (CO), particulate matter (PM), and polycyclic aromatic hydrocarbons (PAHs) from the combustion of pellets. In this study, pine wood and corn straw pellets were burned in a pellet burner (2.6 kW) and the EFs of CO, organic carbon, elemental carbon, PM, and PAHs (EFCO, EFOC, EFEC, EFPM, and EFPAH) were determined. The average EFCO, EFOC, EFEC, and EFPM were 1520±1170, 8.68±11.4, 11.2±8.7, and 188±87 mg/MJ for corn straw pellets, and 266±137, 5.74±7.17, 2.02±1.57, and 71.0±54.0 mg/MJ for pine wood pellets, respectively. Total carbonaceous carbon constituted 8 to 14% of the PM mass emitted. The measured values of EFPAH for the two pellets were 1.02±0.64 and 0.506±0.360 mg/MJ, respectively. The secondary side air supply in the pellet burner did not change the EFs of most pollutants significantly (p > 0.05). The only exceptions were EFOC and EFPM for pine wood pellets because of reduced combustion temperatures with the increased air supply. In comparison with EFs for the raw pine wood and corn straw, EFCO, EFOC, EFEC, and EFPM for pellets were significantly lower than those for raw fuels (p < 0.05). However, the differences in EFPAH were not significant (p > 0.05). Based on the measured EFs and thermal efficiencies, it was estimated that 95, 98, 98, 88, and 71% reductions in the total emissions of CO, OC, EC, PM, and PAHs could be achieved by replacing the raw biomass fuels combusted in traditional cooking stoves with pellets burned in modern

  3. Reductions in emissions of carbonaceous particulate matter and polycyclic aromatic hydrocarbons from combustion of biomass pellets in comparison with raw fuel burning.

    PubMed

    Shen, Guofeng; Tao, Shu; Wei, Siye; Zhang, Yanyan; Wang, Rong; Wang, Bin; Li, Wei; Shen, Huizhong; Huang, Ye; Chen, Yuanchen; Chen, Han; Yang, Yifeng; Wang, Wei; Wei, Wen; Wang, Xilong; Liu, Wenxing; Wang, Xuejun; Masse Simonich, Staci L y

    2012-06-05

    Biomass pellets are emerging as a cleaner alternative to traditional biomass fuels. The potential benefits of using biomass pellets include improving energy utilization efficiency and reducing emissions of air pollutants. To assess the environmental, climate, and health significance of replacing traditional fuels with biomass pellets, it is critical to measure the emission factors (EFs) of various pollutants from pellet burning. However, only a few field measurements have been conducted on the emissions of carbon monoxide (CO), particulate matter (PM), and polycyclic aromatic hydrocarbons (PAHs) from the combustion of pellets. In this study, pine wood and corn straw pellets were burned in a pellet burner (2.6 kW), and the EFs of CO, organic carbon, elemental carbon, PM, and PAHs (EF(CO), EF(OC), EF(EC), EF(PM), and EF(PAH)) were determined. The average EF(CO), EF(OC), EF(EC), and EF(PM) were 1520 ± 1170, 8.68 ± 11.4, 11.2 ± 8.7, and 188 ± 87 mg/MJ for corn straw pellets and 266 ± 137, 5.74 ± 7.17, 2.02 ± 1.57, and 71.0 ± 54.0 mg/MJ for pine wood pellets, respectively. Total carbonaceous carbon constituted 8 to 14% of the PM mass emitted. The measured values of EF(PAH) for the two pellets were 1.02 ± 0.64 and 0.506 ± 0.360 mg/MJ, respectively. The secondary side air supply in the pellet burner did not change the EFs of most pollutants significantly (p > 0.05). The only exceptions were EF(OC) and EF(PM) for pine wood pellets because of reduced combustion temperatures with the increased air supply. In comparison with EFs for the raw pine wood and corn straw, EF(CO), EF(OC), EF(EC), and EF(PM) for pellets were significantly lower than those for raw fuels (p < 0.05). However, the differences in EF(PAH) were not significant (p > 0.05). Based on the measured EFs and thermal efficiencies, it was estimated that 95, 98, 98, 88, and 71% reductions in the total emissions of CO, OC, EC, PM, and PAHs could be achieved by replacing the raw biomass fuels combusted in

  4. Deep Burn: Development of Transuranic Fuel for High-Temperature Helium-Cooled Reactors- Monthly Highlights September 2010

    SciTech Connect

    Snead, Lance Lewis; Besmann, Theodore M; Collins, Emory D; Bell, Gary L

    2010-10-01

    The DB Program monthly highlights report for August 2010, ORNL/TM-2010/184, was distributed to program participants by email on September 17. This report discusses: (1) Core and Fuel Analysis - (a) Core Design Optimization in the HTR (high temperature helium-cooled reactor) Prismatic Design (Logos), (b) Core Design Optimization in the HTR Pebble Bed Design (INL), (c) Microfuel analysis for the DB HTR (INL, GA, Logos); (2) Spent Fuel Management - (a) TRISO (tri-structural isotropic) repository behavior (UNLV), (b) Repository performance of TRISO fuel (UCB); (3) Fuel Cycle Integration of the HTR (high temperature helium-cooled reactor) - Synergy with other reactor fuel cycles (GA, Logos); (4) TRU (transuranic elements) HTR Fuel Qualification - (a) Thermochemical Modeling, (b) Actinide and Fission Product Transport, (c) Radiation Damage and Properties; (5) HTR Spent Fuel Recycle - (a) TRU Kernel Development (ORNL), (b) Coating Development (ORNL), (c) Characterization Development and Support, (d) ZrC Properties and Handbook; and (6) HTR Fuel Recycle - (a) Graphite Recycle (ORNL), (b) Aqueous Reprocessing, (c) Pyrochemical Reprocessing METROX (metal recovery from oxide fuel) Process Development (ANL).

  5. Effect of increased fuel temperature on emissions of oxides of nitrogen from a gas turbine combustor burning natural gas

    NASA Technical Reports Server (NTRS)

    Marchionna, N. R.

    1973-01-01

    An annular gas turbine combustor was tested with heated natural gas fuel to determine the effect of increasing fuel temperature on the formation of oxides of nitrogen. Fuel temperatures ranged from ambient to 800 K (980 F). Combustor pressure was 6 atmospheres and the inlet air temperature ranged from 589 to 894 K (600 to 1150 F). The NOx emission index increased with fuel temperature at a rate of 4 to 9 percent per 100 K (180 F), depending on the inlet air temperature. The rate of increase in NOx was lowest at the highest inlet air temperature tested.

  6. On the Experimental and Theoretical Investigations of Lean Partially Premixed Combustion, Burning Speed, Flame Instability and Plasma Formation of Alternative Fuels at High Temperatures and Pressures

    NASA Astrophysics Data System (ADS)

    Askari, Omid

    composition and thermodynamic properties. The method was applied to compute the thermodynamic properties of hydrogen/air and methane/air plasma mixtures for a wide range of temperatures (1,000-100,000 K), pressures (10-6-100 atm) and different equivalence ratios within flammability limit. In calculating the individual thermodynamic properties of the atomic species, the Debye-Huckel cutoff criterion has been used for terminating the series expression of the electronic partition function. A new differential-based multi-shell model was developed in conjunction with Schlieren photography to measure laminar burning speed and to study the flame instabilities for different alternative fuels such as syngas and GTL. Flame instabilities such as cracking and wrinkling were observed during flame propagation and discussed in terms of the hydrodynamic and thermo-diffusive effects. Laminar burning speeds were measured using pressure rise data during flame propagation and power law correlations were developed over a wide range of temperatures, pressures and equivalence ratios. As a part of this work, the effect of EGR addition and substitution of nitrogen with helium in air on flame morphology and laminar burning speed were extensively investigated. The effect of cell formation on flame surface area of syngas fuel in terms of a newly defined parameter called cellularity factor was also evaluated. In addition to that the experimental onset of auto-ignition and theoretical ignition delay times of premixed GTL/air mixture were determined at high pressures and low temperatures over a wide range of equivalence ratios.

  7. Investigation of thermoelastic stresses induced at high altitudes on aircraft external fuel tanks

    NASA Astrophysics Data System (ADS)

    Mousseau, Stephanie Lynn Steber

    As composite technology has grown over the past several decades, the use of composite materials in military applications has become more feasible and widely accepted. Although composite materials provide many benefits, including strength optimization and reduced weight, damage and repair of these materials creates an additional challenge, especially when operating in a marine environment, such as on a carrier deck. This is evident within the Navy, as excessive damage often leads to the scrapping of F/A-18 External Fuel Tanks. This damage comes in many forms, the most elusive of which is delamination. Often the delamination found on the tanks is beyond repairable limits and the cause unknown, making it difficult to predict and prevent. The purpose of this investigation was to study the structure of the Navy's 330 gallon External Fuel Tanks and investigate one potential cause of delamination, stresses induced at high altitudes by cold temperatures. A stress analysis was completed using finite element software, and validation of the model was accomplished through testing of a scale model specimen. Due to the difficulties in modeling and predicting delamination, such as unknown presence of voids and understanding failure criteria, delamination was not modeled in Abaqus, rather stresses were observed and characteristics were studied to understand the potential for delamination within the layup. In addition, studies were performed to understand the effect of material properties and layup sequence on the stress distribution within the tank. Alternative design solutions are presented which could reduce the radial stresses within the tank, and recommendations are made for further study to understand the trade-offs between stress, cost, and manufacturability.

  8. Evaluation of hoop creep behaviors in long-term dry storage condition of pre-hydrided and high burn-up nuclear fuel cladding

    SciTech Connect

    Kim, Sun-Ki; Bang, J.G.; Kim, D.H.; Yang, Y.S.

    2007-07-01

    Related to the degradation of the mechanical properties of Zr-based nuclear fuel cladding tubes under long term dry storage condition, the mechanical tests which can simulate the degradation of the mechanical properties properly are needed. Especially, the degradation of the mechanical properties by creep mechanism seems to be dominant under long term dry storage condition. Accordingly, in this paper, ring creep tests were performed in order to evaluate the creep behaviors of high burn-up fuel cladding under a hoop loading condition in a hot cell. The tests are performed with Zircaloy-4 fuel cladding whose burn-up is approximately {approx}60,000 MWd/tU in the temperature range from 350 deg. to 550 deg.. The tests are also performed with pre-hydrided Zircaloy-4 and ZIRLO up to 1,000 ppm. First of all, the hoop loading grip for the ring creep test was designed in order that a constant curvature of the specimen was maintained during the creep deformation, and the graphite lubricant was used to minimize the friction between the outer surface of the die insert and the inner surface of the ring specimen. The specimen for the ring creep test was designed to limit the deformation within the gauge section and to maximize the uniformity of the strain distribution. It was confirmed that the mechanical properties under a hoop loading condition can be correctly evaluated by using this test technique. In this paper, secondary creep rate with increasing hydrogen content are drawn, and then kinetic data such as pre-exponential factor and activation energy for creep process are also drawn. In addition, creep life are predicted by obtaining LMP (Larson-Miller parameter) correlation in the function of hydrogen content and applied stress to yield stress ratio. (authors)

  9. Application of Hybrid Laminar Flow Control to Global Range Military Transport Aircraft

    NASA Technical Reports Server (NTRS)

    Lange, Roy H.

    1988-01-01

    A study was conducted to evaluate the application of hybrid laminar flow control (HLFC) to global range military transport aircraft. The global mission included the capability to transport 132,500 pounds of payload 6500 nautical miles, land and deliver the payload and without refueling return 6500 nautical miles to a friendly airbase. The preliminary design studies show significant performance benefits obtained for the HLFC aircraft as compared to counterpart turbulent flow aircraft. The study results at M=0.77 show that the largest benefits of HLFC are obtained with a high wing with engines on the wing configuration. As compared with the turbulent flow baseline aircraft, the high wing HLFC aircraft shows 17 percent reduction in fuel burned, 19.2 percent increase in lift-to-drag ratio, an insignificant increase in operating weight, and a 7.4 percent reduction in gross weight.

  10. H.R. 4984: A Bill to amend the Solid Waste Disposal Act to regulate the use of hazardous waste as fuel for energy recovery, the operation of cement kilns that burn hazardous waste as fuel, the disposal of cement kiln dust waste, and related activities. Introduced in the House of Representatives, One Hundred Third Congress, Second Session, August 18, 1994

    SciTech Connect

    1994-12-31

    The report H.R. 4984 is a bill to amend the Solid Waste Disposal Act to regulate the use of hazardous waste as fuel for energy recovery, the operation of cement kilns that burn hazardous waste as fuel, the disposal of cement kiln dust waste. The proposed legislative text is provided.

  11. Overview: Small Aircraft Transportation System Airborne Remote Sensing Fuel Droplet Evaporation

    NASA Technical Reports Server (NTRS)

    Bowen, Brent (Editor); Holmes, Bruce; Gogos, George; Narayanan, Ram; Smith, Russell; Woods, Sara

    2004-01-01

    , Codes, and Strategic Enterprises. During the first year of funding, Nebraska established open and frequent lines of communication with university affairs officers and other key personnel at all NASA Centers and Enterprises, and facilitated the development of collaborations between and among junior faculty in the state and NASA researchers. As a result, Nebraska initiated a major research cluster, the Small Aircraft Transportation System Nebraska Implementation Template.

  12. Simultaneous NOx and hydrocarbon emissions control for lean-burn engines using low-temperature solid oxide fuel cell at open circuit.

    PubMed

    Huang, Ta-Jen; Hsu, Sheng-Hsiang; Wu, Chung-Ying

    2012-02-21

    The high fuel efficiency of lean-burn engines is associated with high temperature and excess oxygen during combustion and thus is associated with high-concentration NO(x) emission. This work reveals that very high concentration of NO(x) in the exhaust can be reduced and hydrocarbons (HCs) can be simultaneously oxidized using a low-temperature solid oxide fuel cell (SOFC). An SOFC unit is constructed with Ni-YSZ as the anode, YSZ as the electrolyte, and La(0.6)Sr(0.4)CoO(3) (LSC)-Ce(0.9)Gd(0.1)O(1.95) as the cathode, with or without adding vanadium to LSC. SOFC operation at 450 °C and open circuit can effectively treat NO(x) over the cathode at a very high concentration in the simulated exhaust. Higher NO(x) concentration up to 5000 ppm can result in a larger NO(x) to N(2) rate. Moreover, a higher oxygen concentration promotes NO conversion. Complete oxidation of HCs can be achieved by adding silver to the LSC current collecting layer. The SOFC-based emissions control system can treat NO(x) and HCs simultaneously, and can be operated without consuming the anode fuel (a reductant) at near the engine exhaust temperature to eliminate the need for reductant refilling and extra heating.

  13. Raman micro-spectroscopy of UOX and MOX spent nuclear fuel characterization and oxidation resistance of the high burn-up structure

    NASA Astrophysics Data System (ADS)

    Jegou, C.; Gennisson, M.; Peuget, S.; Desgranges, L.; Guimbretière, G.; Magnin, M.; Talip, Z.; Simon, P.

    2015-03-01

    Raman micro-spectroscopy was applied to study the structure and oxidation resistance of UO2 (burnup 60 GWd/tHM) and MOX (burnup 47 GWd/tHM) irradiated fuels. The Raman technique, adapted to working under extreme conditions, enabled structural information to be obtained at the cubic micrometer scale in various zones of interest within irradiated fuel (central and zones like the Rim for UOX60, and the plutonium-enriched agglomerates for MOX47 characterized by a high burn-up structure), and the study of their oxidation resistance. As regards the structural information after irradiation, the spectra obtained make up a set of data consistent with the systematic presence of the T2g band characteristic of the fluorite structure, and of a triplet band located between 500 and 700 cm-1. The existence of this triplet can be attributed to the presence of defects originating in changes to the fuel chemistry occurring in the reactor (presence of fission products) and to the accumulation of irradiation damage. As concerns the oxidation resistance of the different zones of interest, Raman spectroscopy results confirmed the good stability of the restructured zones (plutonium-enriched agglomerates and Rim) rich in fission products compared to the non-restructured UO2 grains. A greater structural stability was noticed in the case of high plutonium content agglomerates, as this element favors the maintenance of the fluorite structure.

  14. Biomass Burning

    Atmospheric Science Data Center

    2015-07-27

    Projects:  Biomass Burning Definition/Description:  Biomass Burning: This data set represents the geographical and temporal distribution of total amount of biomass burned. These data may be used in general circulation models (GCMs) and ...

  15. Burn Institute

    MedlinePlus

    ... Programs - Fire and Burn Prevention - - Fire Safe Kids - - Senior Smoke Alarm Program - - National Scald Campaign - - Community Services - Burn Survivor Support - - Camp Beyond the Scars - - Retreats - - Burn Survivor & Caregiver Support Groups - - Scholarship Program - - Emergency Needs & Special Assistance Fund - - Red ...

  16. Turboprop Cargo Aircraft Systems study, phase 1

    NASA Technical Reports Server (NTRS)

    Muehlbauer, J. C.; Hewell, J. G., Jr.; Lindenbaum, S. P.; Randall, C. C.; Searle, N.; Stone, F. R., Jr.

    1980-01-01

    The effects of advanced propellers (propfan) on aircraft direct operating costs, fuel consumption, and noiseprints were determined. A comparison of three aircraft selected from the results with competitive turbofan aircraft shows that advanced turboprop aircraft offer these potential benefits, relative to advanced turbofan aircraft: 21 percent fuel saving, 26 percent higher fuel efficiency, 15 percent lower DOCs, and 25 percent shorter field lengths. Fuel consumption for the turboprop is nearly 40 percent less than for current commercial turbofan aircraft. Aircraft with both types of propulsion satisfy current federal noise regulations. Advanced turboprop aircraft have smaller noiseprints at 90 EPNdB than advanced turbofan aircraft, but large noiseprints at 70 and 80 EPNdB levels, which are usually suggested as quietness goals. Accelerated development of advanced turboprops is strongly recommended to permit early attainment of the potential fuel saving. Several areas of work are identified which may produce quieter turboprop aircraft.

  17. Cyclic variations of fuel-droplet distribution during the early intake stroke of a lean-burn stratified-charge spark-ignition engine

    NASA Astrophysics Data System (ADS)

    Aleiferis, P. G.; Hardalupas, Y.; Taylor, A. M. K. P.; Ishii, K.; Urata, Y.

    2005-11-01

    Lean-burn spark-ignition engines exhibit higher efficiency and lower specific emissions in comparison with stoichiometrically charged engines. However, as the air-to-fuel (A/F) ratio of the mixture is made leaner than stoichiometric, cycle-by-cycle variations in the early stages of in-cylinder combustion, and subsequent indicated mean effective pressure (IMEP), become more pronounced and limit the range of lean-burn operation. Viable lean-burn engines promote charge stratification, the mixture near the spark plug being richer than the cylinder volume averaged value. Recent work has shown that cycle-by-cycle variations in the early stages of combustion in a stratified-charge engine can be associated with variations in both the local value of A/F ratio near the spark plug around ignition timing, as well as in the volume averaged value of the A/F ratio. The objective of the current work was to identify possible sources of such variability in A/F ratio by studying the in-cylinder field of fuel-droplet distribution during the early intake stroke. This field was visualised in an optical single-cylinder 4-valve pentroof-type spark-ignition engine by means of laser-sheet illumination in planes parallel to the cylinder head gasket 6 and 10 mm below the spark plug. The engine was run with port-injected isooctane at 1500 rpm with 30% volumetric efficiency and air-to-fuel ratio corresponding to both stoichiometric firing (A/F=15, Φ =1.0) and mixture strength close to the lean limit of stable operation (A/F=22, Φ =0.68). Images of Mie intensity scattered by the cloud of fuel droplets were acquired on a cycle-by-cycle basis. These were studied in order to establish possible correlations between the cyclic variations in size, location and scattered-light intensity of the cloud of droplets with the respective variations in IMEP. Because of the low level of Mie intensity scattered by the droplets and because of problems related to elastic scattering on the walls of the combustion

  18. Flight and Preflight Tests of a Ram Jet Burning Magnesium Slurry Fuel and Utilizing a Solid-propellant Gas Generator for Fuel Expulsion

    NASA Technical Reports Server (NTRS)

    Bartlett, Walter, A , jr; Hagginbotham, William K , Jr

    1955-01-01

    Data obtained from the first flight test of a ram jet utilizing a magnesium slurry fuel are presented. The ram jet accelerated from a Mach number of 1.75 to a Mach number of 3.48 in 15.5 seconds. During this period a maximum values of air specific impulse and gross thrust coefficient were calculated to be 151 seconds and 0.658, respectively. The rocket gas generator used as a fuel-pumping system operated successfully.

  19. Turboelectric Distributed Propulsion in a Hybrid Wing Body Aircraft

    NASA Technical Reports Server (NTRS)

    Felder, James L.; Brown, Gerald V.; DaeKim, Hyun; Chu, Julio

    2011-01-01

    The performance of the N3-X, a 300 passenger hybrid wing body (HWB) aircraft with turboelectric distributed propulsion (TeDP), has been analyzed to see if it can meet the 70% fuel burn reduction goal of the NASA Subsonic Fixed Wing project for N+3 generation aircraft. The TeDP system utilizes superconducting electric generators, motors and transmission lines to allow the power producing and thrust producing portions of the system to be widely separated. It also allows a small number of large turboshaft engines to drive any number of propulsors. On the N3-X these new degrees of freedom were used to (1) place two large turboshaft engines driving generators in freestream conditions to maximize thermal efficiency and (2) to embed a broad continuous array of 15 motor driven propulsors on the upper surface of the aircraft near the trailing edge. That location maximizes the amount of the boundary layer ingested and thus maximizes propulsive efficiency. The Boeing B777-200LR flying 7500 nm (13890 km) with a cruise speed of Mach 0.84 and an 118100 lb payload was selected as the reference aircraft and mission for this study. In order to distinguish between improvements due to technology and aircraft configuration changes from those due to the propulsion configuration changes, an intermediate configuration was included in this study. In this configuration a pylon mounted, ultra high bypass (UHB) geared turbofan engine with identical propulsion technology was integrated into the same hybrid wing body airframe. That aircraft achieved a 52% reduction in mission fuel burn relative to the reference aircraft. The N3-X was able to achieve a reduction of 70% and 72% (depending on the cooling system) relative to the reference aircraft. The additional 18% - 20% reduction in the mission fuel burn can therefore be attributed to the additional degrees of freedom in the propulsion system configuration afforded by the TeDP system that eliminates nacelle and pylon drag, maximizes boundary

  20. Burns and military clothing.

    PubMed

    McLean, A D

    2001-02-01

    Burn injury is a ubiquitous threat in the military environment. The risks during combat are well recognised, but the handling of fuel, oil, munitions and other hot or flammable materials during peacetime deployment and training also imposes an inherent risk of accidental burn injury. Over the last hundred years, the burn threat in combat has ranged from nuclear weapons to small shoulder-launched missiles. Materials such as napalm and white phosphorus plainly present a risk of burn, but the threat extends to encompass personnel in vehicles attacked by anti-armour weapons, large missiles, fuel-air explosives and detonations/conflagrations on weapons platforms such as ships. Large numbers of burn casualties were caused at Pearl Harbor, in Hiroshima and Nagasaki, Vietnam, during the Arab/Israeli Wars and in the Falkland Islands conflict. The threat from burns is unlikely to diminish, indeed new developments in weapons seek to exploit the vulnerability of the serviceman and servicewoman to burns. Clothing can be a barrier to some types of burn--both inherently in the properties of the material, but also by trapping air between clothing layers. Conversely, ignition of the clothing may exacerbate a burn. There is hearsay that burnt clothing products within a wound may complicate the clinical management, or that materials that melt (thermoplastic materials) should not be worn if there is a burn threat. This paper explores the incidence of burn injury, the mechanisms of heat transfer to bare skin and skin covered by materials, and the published evidence for the complication of wound management by materials. Even light-weight combat clothing can offer significant protection to skin from short duration flash burns; the most vulnerable areas are the parts of the body not covered--face and hands. Multilayered combat clothing can offer significant protection for short periods from engulfment by flames; lightweight tropical wear with few layers offers little protection. Under