Science.gov

Sample records for aircraft jet fuel

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. Inerting Aircraft Fuel Systems Using Exhaust Gases

    NASA Technical Reports Server (NTRS)

    Hehemann, David G.

    2002-01-01

    Our purpose in this proposal was to determine the feasibility of using carbon dioxide, possibly obtained from aircraft exhaust gases as a substance to inert the fuel contained in fuel tanks aboard aircraft. To do this, we decided to look at the effects carbon dioxide has upon commercial Jet-A aircraft fuel. In particular, we looked at the solubility of CO2 in Jet-A fuel, the pumpability of CO2-saturated Jet-A fuel, the flashpoint of Jet-A fuel under various mixtures of air and CO2, the static outgassing of CO2-Saturated Jet-A fuel and the dynamic outgassing of Jet-A fuel during pumping of Jet-A fuel.

  11. Renewable jet fuel.

    PubMed

    Kallio, Pauli; Pásztor, András; Akhtar, M Kalim; Jones, Patrik R

    2014-04-01

    Novel strategies for sustainable replacement of finite fossil fuels are intensely pursued in fundamental research, applied science and industry. In the case of jet fuels used in gas-turbine engine aircrafts, the production and use of synthetic bio-derived kerosenes are advancing rapidly. Microbial biotechnology could potentially also be used to complement the renewable production of jet fuel, as demonstrated by the production of bioethanol and biodiesel for piston engine vehicles. Engineered microbial biosynthesis of medium chain length alkanes, which constitute the major fraction of petroleum-based jet fuels, was recently demonstrated. Although efficiencies currently are far from that needed for commercial application, this discovery has spurred research towards future production platforms using both fermentative and direct photobiological routes. PMID:24679258

  12. Renewable jet fuel.

    PubMed

    Kallio, Pauli; Pásztor, András; Akhtar, M Kalim; Jones, Patrik R

    2014-04-01

    Novel strategies for sustainable replacement of finite fossil fuels are intensely pursued in fundamental research, applied science and industry. In the case of jet fuels used in gas-turbine engine aircrafts, the production and use of synthetic bio-derived kerosenes are advancing rapidly. Microbial biotechnology could potentially also be used to complement the renewable production of jet fuel, as demonstrated by the production of bioethanol and biodiesel for piston engine vehicles. Engineered microbial biosynthesis of medium chain length alkanes, which constitute the major fraction of petroleum-based jet fuels, was recently demonstrated. Although efficiencies currently are far from that needed for commercial application, this discovery has spurred research towards future production platforms using both fermentative and direct photobiological routes.

  13. 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

  14. 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.

  15. Advanced thermally stable jet fuels

    SciTech Connect

    Schobert, H.H.

    1999-01-31

    The Pennsylvania State University program in advanced thermally stable coal-based jet fuels has five broad objectives: (1) Development of mechanisms of degradation and solids formation; (2) Quantitative measurement of growth of sub-micrometer and micrometer-sized particles suspended in fuels during thermal stressing; (3) Characterization of carbonaceous deposits by various instrumental and microscopic methods; (4) Elucidation of the role of additives in retarding the formation of carbonaceous solids; (5) Assessment of the potential of production of high yields of cycloalkanes by direct liquefaction of coal. Future high-Mach aircraft will place severe thermal demands on jet fuels, requiring the development of novel, hybrid fuel mixtures capable of withstanding temperatures in the range of 400--500 C. In the new aircraft, jet fuel will serve as both an energy source and a heat sink for cooling the airframe, engine, and system components. The ultimate development of such advanced fuels requires a thorough understanding of the thermal decomposition behavior of jet fuels under supercritical conditions. Considering that jet fuels consist of hundreds of compounds, this task must begin with a study of the thermal degradation behavior of select model compounds under supercritical conditions. The research performed by The Pennsylvania State University was focused on five major tasks that reflect the objectives stated above: Task 1: Investigation of the Quantitative Degradation of Fuels; Task 2: Investigation of Incipient Deposition; Task 3: Characterization of Solid Gums, Sediments, and Carbonaceous Deposits; Task 4: Coal-Based Fuel Stabilization Studies; and Task 5: Exploratory Studies on the Direct Conversion of Coal to High Quality Jet Fuels. The major findings of each of these tasks are presented in this executive summary. A description of the sub-tasks performed under each of these tasks and the findings of those studies are provided in the remainder of this volume

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. Risk factors of jet fuel combustion products.

    PubMed

    Tesseraux, Irene

    2004-04-01

    Air travel is increasing and airports are being newly built or enlarged. Concern is rising about the exposure to toxic combustion products in the population living in the vicinity of large airports. Jet fuels are well characterized regarding their physical and chemical properties. Health effects of fuel vapors and liquid fuel are described after occupational exposure and in animal studies. Rather less is known about combustion products of jet fuels and exposure to those. Aircraft emissions vary with the engine type, the engine load and the fuel. Among jet aircrafts there are differences between civil and military jet engines and their fuels. Combustion of jet fuel results in CO2, H2O, CO, C, NOx, particles and a great number of organic compounds. Among the emitted hydrocarbons (HCs), no compound (indicator) characteristic for jet engines could be detected so far. Jet engines do not seem to be a source of halogenated compounds or heavy metals. They contain, however, various toxicologically relevant compounds including carcinogenic substances. A comparison between organic compounds in the emissions of jet engines and diesel vehicle engines revealed no major differences in the composition. Risk factors of jet engine fuel exhaust can only be named in context of exposure data. Using available monitoring data, the possibilities and limitations for a risk assessment approach for the population living around large airports are presented. The analysis of such data shows that there is an impact on the air quality of the adjacent communities, but this impact does not result in levels higher than those in a typical urban environment.

  2. Risk factors of jet fuel combustion products.

    PubMed

    Tesseraux, Irene

    2004-04-01

    Air travel is increasing and airports are being newly built or enlarged. Concern is rising about the exposure to toxic combustion products in the population living in the vicinity of large airports. Jet fuels are well characterized regarding their physical and chemical properties. Health effects of fuel vapors and liquid fuel are described after occupational exposure and in animal studies. Rather less is known about combustion products of jet fuels and exposure to those. Aircraft emissions vary with the engine type, the engine load and the fuel. Among jet aircrafts there are differences between civil and military jet engines and their fuels. Combustion of jet fuel results in CO2, H2O, CO, C, NOx, particles and a great number of organic compounds. Among the emitted hydrocarbons (HCs), no compound (indicator) characteristic for jet engines could be detected so far. Jet engines do not seem to be a source of halogenated compounds or heavy metals. They contain, however, various toxicologically relevant compounds including carcinogenic substances. A comparison between organic compounds in the emissions of jet engines and diesel vehicle engines revealed no major differences in the composition. Risk factors of jet engine fuel exhaust can only be named in context of exposure data. Using available monitoring data, the possibilities and limitations for a risk assessment approach for the population living around large airports are presented. The analysis of such data shows that there is an impact on the air quality of the adjacent communities, but this impact does not result in levels higher than those in a typical urban environment. PMID:15093276

  3. Compatibility of elastomers in alternate jet fuels

    NASA Technical Reports Server (NTRS)

    Kalfayan, S. H.; Fedors, R. F.; Reilly, W. W.

    1979-01-01

    The compatibility of elastomeric compositions of known resistance to aircraft fuels was tested for potential use in Jet A type fuels obtainable from alternate sources, such as coal. Since such fuels were not available at the time, synthetic alternate fuels were prepared by adding tetralin to a petroleum based Jet A type fuel to simulate coal derived fuels which are expected to contain higher amounts of aromatic and hydroaromatic hydrocarbons. The elastomeric compounds tested were based on butadiene-acrylonitrile rubber, a castable Thiokol polysulfide rubber, and a castable fluorosilicone rubber. Batches of various cross-link densities of these rubbers were made and their chemical stress relaxation behavior in fuel, air, and nitrogen, their swelling properties, and response to mechanical testing were determined.

  4. 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.

  5. Visualizing interior and exterior jet aircraft noise

    NASA Astrophysics Data System (ADS)

    Moondra, Manmohan S.

    In today's competitive aerospace industry, the quest for quiet has drawn significant attention to both the interior and exterior design of an airplane. Understanding the noise generation mechanisms of a jet aircraft is a crucial first step toward developing the most cost-effective noise and vibrations abatement methods. In this investigation, the Helmholtz Equation Least Squares (HELS) based nearfield acoustic holography will be used to understand noise transmission caused by jet engine and turbulence into the fuselage of a jet aircraft cruising at 30,000 ft. Modern propulsive jet engines produce exterior noise sources with a high amplitude noise field and complicated characteristics, which makes them very difficult to characterize. In particular, there are turbulent eddies that are moving through the jet at high speeds along the jet boundary. These turbulent eddies in the shear layer produce a directional and frequency dependent noise. The original HELS approach assumes a spherical source at the origin and computes the acoustic field based on spherical emission from this source. This assumption of one source at the origin is not sufficient to characterize a complex source like a jet. As such, a modified HELS approach is introduced that will help improve the source characterization as it is not dependent on a single source at the origin but a number of virtual sources throughout the space. Custom microphones are created to take acoustic pressure measurements around the jet engine. These measured acoustic pressures are then taken as input to the modified HELS algorithm to visualize the noise pattern of a subsonic jet engine.

  6. Factors affecting the retirement of commercial transport jet aircraft

    NASA Technical Reports Server (NTRS)

    Spencer, F. A.

    1979-01-01

    The historical background of the technology and economics of aircraft replacement and retirement in the prejet era is reviewed in order to determine whether useful insights can be obtained applicable to the jet era. Significant differences between the two periods are noted. New factors are identified and examined. Topics discussed include concern over current policies regarding deregulation, regulatory reform, and retroactive noise regulations; financing and compliance legislation; aging; economic environment and inflation; technological progress; fuel efficiency and cost; and a financial perspective of replacement decisions.

  7. Radiant Energy Power Source for Jet Aircraft

    SciTech Connect

    Doellner, O.L.

    1992-02-01

    This report beings with a historical overview on the origin and early beginnings of Radiant Energy Power Source for Jet Aircraft. The report reviews the work done in Phase I (Grant DE-FG01-82CE-15144) and then gives a discussion of Phase II (Grant DE-FG01-86CE-15301). Included is a reasonably detailed discussion of photovoltaic cells and the research and development needed in this area. The report closes with a historical perspective and summary related to situations historically encountered on projects of this nature. 15 refs.

  8. 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.

  9. 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.

  10. PERSONAL EXPOSURE TO JP-8 JET FUEL VAPORS AND EXHAUST AT AIR FORCE BASES

    EPA Science Inventory

    JP-8 jet fuel (similar to commercial/international jet A-1 fuel) is the standard military fuel for all types of vehicles, including the U.S. Air Force aircraft inventory. As such, JP-8 presents the most common chemical exposure in the Air Force, particularly for flight and gro...

  11. Fuels characterization studies. [jet fuels

    NASA Technical Reports Server (NTRS)

    Seng, G. T.; Antoine, A. C.; Flores, F. J.

    1980-01-01

    Current analytical techniques used in the characterization of broadened properties fuels are briefly described. Included are liquid chromatography, gas chromatography, and nuclear magnetic resonance spectroscopy. High performance liquid chromatographic ground-type methods development is being approached from several directions, including aromatic fraction standards development and the elimination of standards through removal or partial removal of the alkene and aromatic fractions or through the use of whole fuel refractive index values. More sensitive methods for alkene determinations using an ultraviolet-visible detector are also being pursued. Some of the more successful gas chromatographic physical property determinations for petroleum derived fuels are the distillation curve (simulated distillation), heat of combustion, hydrogen content, API gravity, viscosity, flash point, and (to a lesser extent) freezing point.

  12. Black carbon emissions reductions from combustion of alternative jet fuels

    NASA Astrophysics Data System (ADS)

    Speth, Raymond L.; Rojo, Carolina; Malina, Robert; Barrett, Steven R. H.

    2015-03-01

    Recent measurement campaigns for alternative aviation fuels indicate that black carbon emissions from gas turbines are reduced significantly with the use of alternative jet fuels that are low in aromatic content. This could have significant climate and air quality-related benefits that are currently not accounted for in environmental assessments of alternative jet fuels. There is currently no predictive way of estimating aircraft black carbon emissions given an alternative jet fuel. We examine the results from available measurement campaigns and propose a first analytical approximation (termed 'ASAF') of the black carbon emissions reduction associated with the use of paraffinic alternative jet fuels. We establish a relationship between the reduction in black carbon emissions relative to conventional jet fuel for a given aircraft, thrust setting relative to maximum rated thrust, and the aromatic volume fraction of the (blended) alternative fuel. The proposed relationship is constrained to produce physically meaningful results, makes use of only one free parameter and is found to explain a majority of the variability in measurements across the engines and fuels that have been tested.

  13. Jet fuel instability mechanisms

    NASA Technical Reports Server (NTRS)

    Daniel, S. R.

    1985-01-01

    The mechanisms of the formation of fuel-insoluble deposits were studied in several real fuels and in a model fuel consisting of tetralin in dodecane solution. The influence of addition to the fuels of small concentrations of various compounds on the quantities of deposits formed and on the formation and disappearance of oxygenated species in solution was assessed. The effect of temperature on deposit formation was also investigated over the range of 308-453 K.

  14. Fuel-conservative guidance system for powered-lift aircraft

    NASA Technical Reports Server (NTRS)

    Erzberger, H.; Mclean, J. D.

    1979-01-01

    A concept for automatic terminal area guidance, comprising two modes of operation, was developed and evaluated in flight tests. In the predictive mode, fuel efficient approach trajectories are synthesized in fast time. In the tracking mode, the synthesized trajectories are reconstructed and tracked automatically. An energy rate performance model derived from the lift, drag, and propulsion system characteristics of the aircraft is used in the synthesis algorithm. The method optimizes the trajectory for the initial aircraft position and wind and temperature profiles encountered during each landing approach. The design theory and the results of simulations and flight tests using the Augmentor Wing Jet STOL Research Aircraft are described.

  15. Military jet fuels, 1944-1987. Summary report, October 1985-October 1987

    SciTech Connect

    Martel, C.R.

    1987-11-01

    This report consists of a brief history of US military fuels for aircraft turbine jet engines and ramjet engines. It discusses the requirements of past and current US military jet-fuel specifications, when and why the specification requirements originated, and the importance of these requirements today. The purpose and origin of the various specification test methods are presented, and an extensive discussion of jet-fuel additives is provided. This report should be of value to anyone involved in research and development, logistics, and use of jet-fuels. It is hoped that it will serve as a handy reference for the jet fuel specialist.

  16. 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.

  17. Coal liquefaction to increase jet fuel production

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Processing concept that increases supply of jet fuel has been developed as part of study on methods for converting coal to hydrogen, methane, and jet fuel. Concept takes advantage of high aromatic content of coal-derived liquids to make high-octane gasoline, instead of destroying aromatics to make jet fuel.

  18. Jet Fuel Thermal Stability

    NASA Technical Reports Server (NTRS)

    Taylor, W. F. (Editor)

    1979-01-01

    Various aspects of the thermal stability problem associated with the use of broadened-specification and nonpetroleum-derived turbine fuels are addressed. The state of the art is reviewed and the status of the research being conducted at various laboratories is presented. Discussions among representatives from universities, refineries, engine and airframe manufacturers, airlines, the Government, and others are presented along with conclusions and both broad and specific recommendations for future stability research and development. It is concluded that significant additional effort is required to cope with the fuel stability problems which will be associated with the potentially poorer quality fuels of the future such as broadened specification petroleum fuels or fuels produced from synthetic sources.

  19. 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.

  20. Cleanup of a jet fuel spill

    NASA Astrophysics Data System (ADS)

    Fesko, Steve

    1996-11-01

    Eaton operates a corporate aircraft hanger facility in Battle Creek, Michigan. Tests showed that two underground storage tanks leaked. Investigation confirmed this release discharged several hundred gallons of Jet A kerosene into the soil and groundwater. The oil moved downward approximately 30 feet and spread laterally onto the water table. Test results showed kerosene in the adsorbed, free and dissolved states. Eaton researched and investigated three clean-up options. They included pump and treat, dig and haul and bioremediation. Jet fuel is composed of readily biodegradable hydrocarbon chains. This fact coupled with the depth to groundwater and geologic setting made bioremediation the low cost and most effective alternative. A recovery well was installed at the leading edge of the dissolved contamination. A pump moved water from this well into a nutrient addition system. Nutrients added included nitrogen, phosphorous and potassium. Additionally, air was sparged into the water. The water was discharged into an infiltration gallery installed when the underground storage tanks were removed. Water circulated between the pump and the infiltration basin in a closed loop fashion. This oxygenated, nutrient rich water actively and aggressively treated the soils between the bottom of the gallery and the top of the groundwater and the groundwater. The system began operating in August of 1993 and reduced jet fuel to below detection levels. In August of 1995 The State of Michigan issued a clean closure declaration to the site.

  1. Studies of jet fuel additives using the quartz crystal microbalance and pressure monitoring at 140 C

    SciTech Connect

    Zabarnick, S.; Grinstead, R.R. . Aerospace Mechanics Div./KL-463)

    1994-11-01

    Recent advances in jet aircraft and engine technology have placed an ever increasing heat load on the aircraft. The bulk of this excess heat is absorbed by the aircraft fuel, as jet fuel is used as the primary coolant for the numerous heat sources. The quartz crystal microbalance (QCM) and pressure monitoring are used for the evaluation of jet fuel additives for the improvement of jet fuel thermal stability. The mechanisms of additive behavior are determined by measuring the time-dependent deposition with the QCM and oxidation by pressure measurements. Studies at various additive concentrations permits the determination of optimum additive concentrations. Additive packages made of mixtures of antioxidants, detergent/dispersants, and metal deactivators are shown to yield good improvements in thermal stability over a wide range of jet fuel types.

  2. 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.

  3. Advanced Thermally Stable Jet Fuels

    SciTech Connect

    A. Boehman; C. Song; H. H. Schobert; M. M. Coleman; P. G. Hatcher; S. Eser

    1998-01-01

    The Penn State program in advanced thermally stable jet fuels has five components: 1) development of mechanisms of degradation and solids formation; 2) quantitative measurement of growth of sub-micrometer and micrometer-sized particles during thermal stressing; 3) characterization of carbonaceous deposits by various instrumental and microscopic methods; 4) elucidation of the role of additives in retarding the formation of carbonaceous solids; and 5) assessment of the potential of producing high yields of cycloalkanes and hydroaromatics from coal.

  4. Factors affecting the retirement of commercial transport jet aircraft

    NASA Technical Reports Server (NTRS)

    Spencer, F. A.; Swanson, J. A.

    1978-01-01

    A brief historical background of the technology and economics of aircraft replacement and retirement in the prejet era is presented to see whether useful insights can be obtained applicable to the jet area. Significant differences between the two periods were demonstated. Current technological and operational economic perspectives were investigated in detail. Some conclusions are drawn to aircraft retirement policies.

  5. 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.

  6. A study of the efficiency of hydrogen liquefaction. [jet aircraft applications

    NASA Technical Reports Server (NTRS)

    Baker, C. R.; Shaner, R. L.

    1976-01-01

    The search for an environmentally acceptable fuel to eventually replace petroleum-based fuels for long-range jet aircraft has singled out liquid hydrogen as an outstanding candidate. Hydrogen liquefaction is discussed, along with the effect of several operating parameters on process efficiency. A feasible large-scale commercial hydrogen liquefaction facility based on the results of the efficiency study is described. Potential future improvements in hydrogen liquefaction are noted.

  7. 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 %.

  8. 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.

  9. Realistic Probability Estimates For Destructive Overpressure Events In Heated Center Wing Tanks Of Commercial Jet Aircraft

    SciTech Connect

    Alvares, N; Lambert, H

    2007-02-07

    The Federal Aviation Administration (FAA) identified 17 accidents that may have resulted from fuel tank explosions on commercial aircraft from 1959 to 2001. Seven events involved JP 4 or JP 4/Jet A mixtures that are no longer used for commercial aircraft fuel. The remaining 10 events involved Jet A or Jet A1 fuels that are in current use by the commercial aircraft industry. Four fuel tank explosions occurred in center wing tanks (CWTs) where on-board appliances can potentially transfer heat to the tank. These tanks are designated as ''Heated Center Wing Tanks'' (HCWT). Since 1996, the FAA has significantly increased the rate at which it has mandated airworthiness directives (ADs) directed at elimination of ignition sources. This effort includes the adoption, in 2001, of Special Federal Aviation Regulation 88 of 14 CFR part 21 (SFAR 88 ''Fuel Tank System Fault Tolerance Evaluation Requirements''). This paper addresses SFAR 88 effectiveness in reducing HCWT ignition source probability. Our statistical analysis, relating the occurrence of both on-ground and in-flight HCWT explosions to the cumulative flight hours of commercial passenger aircraft containing HCWT's reveals that the best estimate of HCWT explosion rate is 1 explosion in 1.4 x 10{sup 8} flight hours. Based on an analysis of SFAR 88 by Sandia National Laboratories and our independent analysis, SFAR 88 reduces current risk of historical HCWT explosion by at least a factor of 10, thus meeting an FAA risk criteria of 1 accident in billion flight hours. This paper also surveys and analyzes parameters for Jet A fuel ignition in HCWT's. Because of the paucity of in-flight HCWT explosions, we conclude that the intersection of the parameters necessary and sufficient to result in an HCWT explosion with sufficient overpressure to rupture the HCWT is extremely rare.

  10. High temperature jet fuel stabilizers

    SciTech Connect

    Yoon, E.M.; Selvaraj, L.; Stallman, J.B.

    1996-10-01

    We have previously discussed the rationale for development of jet fuels with enhanced thermal stability at temperatures above 400{degrees}C. At these temperatures we are encroaching into the so-called pyrolysis regime, where the cleavage of carbon-carbon bonds into free radicals is facile and leads to the rapid degradation of aliphatic hydrocarbons. Notwithstanding, we established that the formation of carbonaceous materials is significantly retarded in hydrocarbon mixtures containing molecules such as benzyl alcohol (BzOH). It was ascertained that BzOH acts as a hydrogen donor capping aliphatic radicals formed at temperatures > 400{degrees}C while transforming into relatively stable products. These results suggested is superior high temperature thermal stabilizers might be found among the more conventional hydrogen donors that find application in coal liquefaction and similar hydrogenation processes. Here we present the results of {open_quotes}screening{close_quotes} and kinetic studies of traditional hydrogen donors, such as tetralin, tetrahydroquinoline and the like, together with simple derivatives designed to test the importance of specific factors in the thermal stabilization of jet fuels.

  11. Combat aircraft jet engine noise studies

    NASA Astrophysics Data System (ADS)

    Lewy, S.; Fournier, G.; Pianko, M.

    Methods of noise prediction and attenuation, based on results obtained in civil applications are presented. Input data for directivity and radiation forecasts are given by measurements of vane and blade pressure fluctuations, and by modal analysis of the spinning waves propagating in the inlet duct. Attention is given to sound generation mechanisms for subsonic and supersonic single jets and bypass jets. Prediction methods, based on Lighthill's equation (tensor due to the turbulence), are discussed, and the various means of jet noise reduction are reviewed. The CEPRA 19 anechoic wind tunnel, which is primarily designed for studying the jet noise radiated in the far field with flight effects is described.

  12. Thermal stability of coal-derived jet fuels in the autoxidative and pyrolytic regimes

    SciTech Connect

    Andresen, J.M.; Strohm, J.J.; Song, C.

    1999-07-01

    Coal-based liquids have a great potential as precursors for advanced jet fuels that meet the more stringent thermal stability requirements for the future high-Mach jet aircraft. In current commercial planes, the fuel may be exposed to temperatures up to 300 C. However, as the flight speed will be increased to high Mach numbers, the fuel is expected to experience temperatures as high as 480 C (900 F) in the future, since the jet fuel also functions as the main coolant for the different electronic and mechanical parts of the aircraft. Even though the residence time at such elevated temperatures is expected to be fairly short (matter of minutes), the jet fuels presently used have shown to form solid deposits that can lead to catastrophic malfunction of the jet aircraft. The current jet fuels are petroleum-derived and consequently rich in linear alkanes, which are highly susceptible to pyrolytic cracking resulting in coking. The thermal stability of a jet fuel in the pyrolytic regime can be greatly enhanced by utilizing liquids rich in cyclo-alkanes. This is the case for hydro-treated coal-derived liquids, where the aromatic structures have been transformed over to their corresponding cyclo-alkanes. An additional problem with jet fuels is the presence of dissolved oxygen (from air), which reacts with the fuel during the autoxidative regime (150--250 C) before the fuel and its oxygenated reaction products enter the pyrolytic regime (400--500 C). Accordingly, this study compares the thermal stability of a linear alkane (tetradecane), a cyclo-alkane (decahydronaphthalene) and a coal-derived jet-fuel as they go through the autoxidative regime into the pyrolytic regime. Differences in chemical reactivity between the linear- and cyclo-alkane have been related to the stability of the coal-derived jet-fuel.

  13. Development of surrogates for aviation jet fuels

    NASA Astrophysics Data System (ADS)

    Nasseri, Seyed Ali

    Surrogate fuels are mixtures of pure hydrocarbons that mimic specific properties of a real fuel. The use of a small number of pure compounds in their formulation ensures that chemical composition is well controlled, helping increase reproducibility of experiments and reduce the computational cost associated with numerical modeling. In this work, surrogate mixtures were developed for Jet A fuel based on correlations between fuel properties (cetane number, smoke point, threshold sooting index (TSI), density, viscosity, boiling point and freezing point) and the nuclear magnetic resonance (NMR) spectra of the fuel as a measure of the fuel's chemical composition. Comparison of the chemical composition and target fuel properties of the surrogate fuels developed in this work to a Jet A fuel sample and other surrogate fuels proposed in the literature revealed the superiority of these surrogate fuels in mimicking the fuel properties of interest.

  14. Spray Characterization of Gas-to-Liquid Synthetic Jet Fuels

    NASA Astrophysics Data System (ADS)

    Kannaiyan, Kumaran; Sadr, Reza; GTL jet fuel Consortium Team

    2012-11-01

    Gas-to-Liquid (GTL) Synthetic Paraffinic Kerosene (SPK) fuel obtained from Fischer-Tropsch synthesis has grabbed the global attention due to its cleaner combustion characteristics. GTL fuels are expected to meet the vital qualities such as atomization, combustion and emission characteristics of conventional jet fuels. It is imperative to understand fuel atomization in order to gain insights on the combustion and emission aspects of an alternative fuel. In this work spray characteristics of GTL-SPK, which could be used as a drop-in fuel in aircraft gas turbine engines, is studied. This work outlines the spray experimental facility, the methodology used and the results obtained using two SPK's with different chemical compositions. The spray characteristics, such as droplet size and distribution, are presented at three differential pressures across a simplex nozzle and compared with that of the conventional Jet A-1 fuel. Experimental results clearly show that although the chemical composition is significantly different between SPK's, the spray characteristics are not very different. This could be attributed to the minimal difference in fluid properties between the SPK's. Also, the spray characteristics of SPK's show close resemblance to the spray characteristics of Jet A-1 fuel.

  15. High-density jet fuels from coal syncrudes: Appendix 4

    SciTech Connect

    Sullivan, R.F.

    1987-01-01

    Very dense jet-boiling-range hydrocarbons can be obtained by hydrotreating and hydrocracking syncrudes made from coal in direct liquefaction processes. Heteroatom impurities must be removed, and most of the aromatics must be hydrogenated at high severity in order to produce kerosene jet fuels from coal syncrudes that meet smoke point and stability specifications. The resulting hydrotreated products consist mainly of naphthenes containing from one to three rings. If hydrocracking is added as a conversion step, some four-ring naphthenes are found in the 250 to 550/sup 0/F jet fuel products. Polycyclic naphthenes are desirable components for jet fuel because of their high volumetric energy contents and low freezing points. Products from the ITSL liquefaction process from bituminous coal had the lowest paraffin contents and the highest densities (for a given boiling range and aromatic content) of any of the coal liquids studied. Actual engine tests, however, would be needed to demonstrate that these fuels qualify for service in jet aircraft. 11 refs., 6 tabs.

  16. 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.

  17. Effects of motion on jet exhaust noise from aircraft

    NASA Technical Reports Server (NTRS)

    Chun, K. S.; Berman, C. H.; Cowan, S. J.

    1976-01-01

    The various problems involved in the evaluation of the jet noise field prevailing between an observer on the ground and an aircraft in flight in a typical takeoff or landing approach pattern were studied. Areas examined include: (1) literature survey and preliminary investigation, (2) propagation effects, (3) source alteration effects, and (4) investigation of verification techniques. Sixteen problem areas were identified and studied. Six follow-up programs were recommended for further work. The results and the proposed follow-on programs provide a practical general technique for predicting flyover jet noise for conventional jet nozzles.

  18. Propane-Fueled Jet Engine

    NASA Astrophysics Data System (ADS)

    Farwell, D. A.; Svenson, A. J.; Ramsier, R. D.

    2001-04-01

    We present our recent efforts to design, construct, and test a gas turbine, or jet, engine. Our design utilizes a turbocharger and ignition system from an automobile, and a flame tube/reaction chamber unit fabricated by hand from stainless steel. Once the engine is running, it is completely self-sustaining as long as there is a fuel supply, which in our case is propane. Air is forced into the intake where it is compressed and then injected into the combustion chamber where it is mixed with propane. The spark plugs ignite the air-propane mixture which burns to produce thrust at the exhaust. We have performed operational tests under different environmental conditions and with several turbochargers. We are currently working on adding a lubrication system to the engine, and will discuss our plan to experiment with the reaction chamber and flame tube design in an effort to improve performance and efficiency. *Corresponding author: rex@uakron.edu

  19. Flight flutter testing of multi-jet aircraft

    NASA Technical Reports Server (NTRS)

    Bartley, J.

    1975-01-01

    Extensive flight flutter tests were conducted by BAC on B-52 and KC-135 prototype airplanes. The need for and importance of these flight flutter programs to Boeing airplane design are discussed. Basic concepts of flight flutter testing of multi-jet aircraft and analysis of the test data will be presented. Exciter equipment and instrumentation employed in these tests will be discussed.

  20. Jet fuel based high pressure solid oxide fuel cell system

    NASA Technical Reports Server (NTRS)

    Gummalla, Mallika (Inventor); Yamanis, Jean (Inventor); Olsommer, Benoit (Inventor); Dardas, Zissis (Inventor); Bayt, Robert (Inventor); Srinivasan, Hari (Inventor); Dasgupta, Arindam (Inventor); Hardin, Larry (Inventor)

    2013-01-01

    A power system for an aircraft includes a solid oxide fuel cell system which generates electric power for the aircraft and an exhaust stream; and a heat exchanger for transferring heat from the exhaust stream of the solid oxide fuel cell to a heat requiring system or component of the aircraft. The heat can be transferred to fuel for the primary engine of the aircraft. Further, the same fuel can be used to power both the primary engine and the SOFC. A heat exchanger is positioned to cool reformate before feeding to the fuel cell. SOFC exhaust is treated and used as inerting gas. Finally, oxidant to the SOFC can be obtained from the aircraft cabin, or exterior, or both.

  1. Jet Fuel Based High Pressure Solid Oxide Fuel Cell System

    NASA Technical Reports Server (NTRS)

    Gummalla, Mallika (Inventor); Yamanis, Jean (Inventor); Olsommer, Benoit (Inventor); Dardas, Zissis (Inventor); Bayt, Robert (Inventor); Srinivasan, Hari (Inventor); Dasgupta, Arindam (Inventor); Hardin, Larry (Inventor)

    2015-01-01

    A power system for an aircraft includes a solid oxide fuel cell system which generates electric power for the aircraft and an exhaust stream; and a heat exchanger for transferring heat from the exhaust stream of the solid oxide fuel cell to a heat requiring system or component of the aircraft. The heat can be transferred to fuel for the primary engine of the aircraft. Further, the same fuel can be used to power both the primary engine and the SOFC. A heat exchanger is positioned to cool reformate before feeding to the fuel cell. SOFC exhaust is treated and used as inerting gas. Finally, oxidant to the SOFC can be obtained from the aircraft cabin, or exterior, or both.

  2. 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.

  3. Twin jet shielding. [for aircraft noise reduction

    NASA Technical Reports Server (NTRS)

    Parthasarathy, S. P.; Cuffel, R. F.; Massier, P. F.

    1979-01-01

    For an over-the-wing/under-the-wing engine configuration on an airplane, the noise produced by the upper jet flow is partially reflected by the lower jet. An analysis has been performed which can be used to predict the distribution of perceived noise levels along the ground plane at take-off for an airplane which is designed to take advantage of the over/under shielding concept. Typical contours of PNL, the shielding benefit in the shadow zone, and the EPNL values at 3.5 nautical miles from brake release as well as EPNL values at sideline at 0.35 nautical miles have been calculated. This has been done for a range of flow parameters characteristic of engines producing inverted velocity profile jets suitable for use in a supersonic cruise vehicle. Reductions up to 6.0 EPNdB in community noise levels can be realized when the over engines are operated at higher thrust and the lower engines simultaneously operated with reduced thrust keeping the total thrust constant.

  4. 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.

  5. Prediction of subsonic aircraft flows with jet exhaust interactions

    NASA Technical Reports Server (NTRS)

    Roberts, D. W.

    1981-01-01

    A numerical procedure to calculate the flow fields resulting from the viscous inviscid interactions that occur when a strong jet exhaust and aircraft flow field coupling exists was developed. The approach divides the interaction region into zones which are either predominantly viscous or inviscid. The flow in the inviscid zone, which surrounds most of the aircraft, is calculated using an existing potential flow code. The viscous flow zone, which encompasses the jet plume, is modeled using a parabolized Navier-Stokes code. The procedure features the coupling of the zonal solutions such that sufficient information is transferred between the zones to preserve the effects of the interactions. The zonal boundaries overlap and the boundary conditions are the information link between zones. An iteration scheme iterates the coupled analysis until convergence has been obtained.

  6. 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.

  7. Acoustic flight testing of advanced design propellers on a JetStar aircraft

    NASA Astrophysics Data System (ADS)

    Lasagna, P.; Mackall, K.

    1981-12-01

    Advanced turboprop-powered aircraft have the potential to reduce fuel consumption by 15 to 30 percent as compared with an equivalent technology turbofan-powered aircraft. An important obstacle to the use of advanced design propellers is the cabin noise generated at Mach numbers up to .8 and at altitudes up to 35,000 feet. As part of the NASA Aircraft Energy Efficiency Program, the near-field acoustic characteristics on a series of advanced design propellers are investigated. Currently, Dryden Flight Research Center is flight testing a series of propellers on a JetStar airplane. The propellers used in the flight test were previously tested in wind tunnels at the Lewis Research Center. Data are presented showing the narrow band spectra, acoustic wave form, and acoustic contours on the fuselage surface. Additional flights with the SR-3 propeller and other advanced propellers are planned in the future.

  8. Acoustic flight testing of advanced design propellers on a JetStar aircraft

    NASA Technical Reports Server (NTRS)

    Lasagna, P.; Mackall, K.

    1981-01-01

    Advanced turboprop-powered aircraft have the potential to reduce fuel consumption by 15 to 30 percent as compared with an equivalent technology turbofan-powered aircraft. An important obstacle to the use of advanced design propellers is the cabin noise generated at Mach numbers up to .8 and at altitudes up to 35,000 feet. As part of the NASA Aircraft Energy Efficiency Program, the near-field acoustic characteristics on a series of advanced design propellers are investigated. Currently, Dryden Flight Research Center is flight testing a series of propellers on a JetStar airplane. The propellers used in the flight test were previously tested in wind tunnels at the Lewis Research Center. Data are presented showing the narrow band spectra, acoustic wave form, and acoustic contours on the fuselage surface. Additional flights with the SR-3 propeller and other advanced propellers are planned in the future.

  9. 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.

  10. 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.

  11. Oxidizability of jet fuels from other countries

    SciTech Connect

    Kovalev, G.I.; Denisova, E.T.; Gogitidze, L.D.; Kuranova, V.I.

    1984-01-01

    This article lists and examines certain physicochemical properties of a number of commercial samples of jet fuels produced in different countries by various companies. The fuels were oxidized in a gasometric unit at 120/sup 0/ and 130/sup 0/C in the presence of dicumyl peroxide (CP) as an oxidation initiator. It is determined that high thermal stability and low content of organic sulfur compounds indicate that the fuels were produced by treating methods that remove heteroorganic trace components that act as natural oxidation inhibitors in straight-run fuels. The kinetic parameters of initiated oxidation of the foreign fuels and the USSR fuels RT and T-6 (which contain Ionol as an antioxidant) are given. It is found that the fuels from Angola and Iraq and the fuels produced by Shell have higher oxidizabilities at elevated temperatures in comparison with the USSR fuels.

  12. Applicability of NSPS emission standards to boilers using Jet A and other non-specified fuels

    SciTech Connect

    Shapira, A.E.; Dumdei, B.E.; Laabs, L.W.; Bennici, S.L.

    1997-12-31

    United Airlines operates two boilers at the Indianapolis Maintenance Center which are subject to federal New Source Performance Standards (NSPS), Subpart Db. This presentation deals with the applicability of federal NSPS emission standards to the boilers when they are running on Jet A fuel. The primary fuel for the boilers is natural gas, with Jet A used as backup fuel. Jet A was selected due to its obvious availability at the aircraft maintenance center and to minimize the risks and obligations of having another storage facility for petroleum products. United has been able to demonstrate to the satisfaction of EPA that Jet A fuel specifications do not match those of the fuels listed in the Subpart Db emission standards. NSPS standards do not prohibit the use of unspecified fuel. The boilers are still subject to emission standards when operating on natural gas, and are also subject to locally-imposed liquid fuel use limitations and to meeting the manufacturer`s predicted emission levels when running on Jet A. The nonapplicability of federal emission standards while firing the boilers on Jet A has allowed United to discontinue operating the continuous opacity monitor thereby saving on equipment and operating cost. This EPA decision could be significant both for other airline facilities which may have need for Jet A as a stationary source combustion fuel, as well as for other industries that use nonspecified fuels.

  13. 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.

  14. Acute toxicity evaluation of JP-8 jet fuel and JP-8 jet fuel containing additives. Final report, November 1995-February 1996

    SciTech Connect

    Wolfe, R.E.; Kinead, E.R.; Feldmann, M.L.; Leahy, H.F.; Jederberg, W.W.

    1996-11-01

    To reduce fuel fouling in current U.S Navy and Air Force aircraft systems and to provide additional heat sink and thermal stability for future systems, the Air Force is developing an improved JP-8 jet fuel (JP-8 + 100). Two companies (Betz and Mobil) have developed additive packages that are currently being tested in aircraft systems. To determine if the additive packages will produce health effects for flightline personnel, acute testing was performed on JP-8 and the two JP-8 + 100 jet fuels. A single oral dose at 5 mg jet fuel/kg body weight to five male and five female F-344 rats, and a single dermal application of 2 g jet fuel/kg body weight applied to five male and five female NZW rabbits resulted in no deaths. No signs of toxic stress were observed, and all animals gained weight over the 14-day observation periods. Single treatment of 0.5 mL neat jet fuel to rabbit skin produced negative results for skin irritation. Guinea pigs tailed to elicit a sensitization response following repeated applications of the jet fuels. Inhalation vapor exposure to JP-8, JP-8 + 100 (Betz), and JP-8 (Mobil) were determined to be >3.43, >3.52, and >3.57 mg/L, respectively. LD% values for aerosol exposure to JP-8, JP-8 + 100 (Betz), and JP-8 + 100 (Mobil) were >4.44, >4.39, and >4.54 mg/L, respectively. Under the conditions of these tests, the additive packages did not potentiate the acute effects normally associated with JP-8 jet fuel exposures.

  15. Advanced thermally stable jet-fuel development program annual report. Volume 2. Compositional factors affecting thermal degradation of jet fuels. Final report, Jul 90-Jul 91

    SciTech Connect

    Song, C.; Eser, S.; Schobert, H.H.; Hatcher, P.G.; Coleman, M.M.

    1992-05-01

    This project focuses on the compositional factors affecting jet fuel thermal stability at high temperatures. The chemical composition of the four jet fuel samples (JP-8C, JP-8P, JP-7P, Jet A1) and Wilsonville middle distillates was characterized by using selective ion monitoring technique in GC-MS analysis. The thermal treatment tests have been performed on jet fuels and a series of model compounds including tetralin, decalin, ethylcyclohexane, butylcyclohexane, n-butylbenzene, t-butylbenzene, n-octane, n-decane, and n-tetradecane. Deposit samples from an actual aircraft fuel stem as well as those produced from jet fuels and model compounds in microautoclaves were characterized by FTIR and polarized-light microscopy. Experiments were conducted to find the optimum amount of antioxidant 2,6-di-tert-butyl-4-methylphenol necessary to minimize the solid formation upon thermal stressing of JP8 neat and Jet A-1 fuel samples. The chemistry of thermal degradation of the fuel and antioxidant mixtures was studied by using FTIR to characterize the liquid products from thermal stressing.

  16. Ion-induced Aerosol-formation By Jet Aircraft: Implications For Contrail- and Cloud-formation

    NASA Astrophysics Data System (ADS)

    Eichkorn, S.; Wilhelm, S.; Arnold, F.

    Jet aircraft produced gaseous ions so called chemiions (CI) may promote the forma- tion of volatile aerosol particles (VAP). VAP are potentially important by acting as water vapor condensation nuclei in contrail- and perhaps even cloud-formation. This ion-induced VAP-formation proceeds via the formation of cluster ions which are suf- ficiently large to form stable VAP upon neutralisation by ion-ion recombination. Here we report the first measurements of large cluster ions in sulfur-poor and -rich exhaust plumes of jet aircraft in flight equipped with modern and old engines. Measurements were performed in the wake of an Airbus A340, a Boeing B707 and the German Re- search Aircraft ATTAS. Our measurements suggest that ion induced VAP-formation takes place and that gaseous sulphuric acid and gaseous low volatility organic com- pounds are involved. For modern engines burning fuel with a typical mean fuel sulfur content sulphuric acid seems to be the most abundant condensate in a contrail-free exhaust-plume.

  17. 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.

  18. 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.

  19. Carbon monoxide exposure from aircraft fueling vehicles.

    PubMed

    McCammon, C S; Halperin, W F; Lemen, R A

    1981-01-01

    Investigators from the National Institute for Occupational Safety and Health observed deficiencies in maintenance of fueling trucks at an international airport. The exhaust system is vented under the front bumper, a standard design on fueling trucks which is intended to minimize the proximity of the exhaust system to the jet fuel in the vehicles. Carbon monoxide levels were measured in the cabs of 17 fueling trucks with windows closed, heaters on, and in different positions relative to the wind. One truck had an average CO level of 300 ppm, two exceeded 100 ppm, five others exceeded 50 ppm, while levels in the other nine averaged less than or equal to 500 ppm. Levels of CO depended on the mechanical condition of the vehicle and the vehicle's orientation to the wind. Stringent maintenance is required as the exhaust design is not fail-safe.

  20. CYTOGENETIC STUDIES IN MICE TREATED WITH THE JET FUELS, JET-A AND JP-8

    EPA Science Inventory

    Cytogenetic studies in mice treated with the jet fuels, Jet-A and JP-8
    Abstract
    The genotoxic potential of the jet fuels, Jet-A and JP-8, were examined in mice treated on the skin with a single dose of 240 ug/mouse. Peripheral blood smears were prepared at the start of the ...

  1. 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.

  2. 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.

  3. Emission FTIR analyses of thin microscopic patches of jet fuel residues deposited on heated metal surfaces

    NASA Technical Reports Server (NTRS)

    Lauer, J. L.; Vogel, P.

    1986-01-01

    The relationship of fuel stability to fuel composition and the development of mechanisms for deposit formation were investigated. Fuel deposits reduce heat transfer efficiency and increase resistance to fuel flow and are highly detrimental to aircraft performance. Infrared emission Fourier transform spectroscopy was chosen as the primary method of analysis because it was sensitive enough to be used in-situ on tiny patches of monolayers or of only a few molecular layers of deposits which generally proved completely insoluble in any nondestructive solvents. Deposits of four base fuels were compared; dodecane, a dodecane/tetralin blend, commercial Jet A fuel, and a broadened-properties jet fuel particularly rich in polynuclear aromatics. Every fuel in turn was provided with and without small additions of such additives as thiophene, furan, pyrrole, and copper and iron naphthenates.

  4. Particle transport in pellet fueled JET (Jet European Torus) plasmas

    SciTech Connect

    Baylor, L.R.

    1990-01-01

    Pellet fueling experiments have been carried out on the Joint European Torus (JET) tokamak with a multi-pellet injector. The pellets are injected at speeds approaching 1400 m/s and penetrate deep into the JET plasma. Highly peaked electron density profiles are achieved when penetration of the pellets approaches or goes beyond the magnetic axis, and these peaked profiles persist for more than two seconds in ohmic discharges and over one second in ICRF heated discharges. In this dissertation, analysis of electron particle transport in multi-pellet fueled JET limiter plasmas under a variety of heating conditions is described. The analysis is carried out with a one and one-half dimensional radial particle transport code to model the experimental density evolution with various particle transport coefficients. These analyses are carried out in plasmas with ohmic heating, ICRF heating, and neural beam heating, in limiter configurations. Peaked density profile cases are generally characterized by diffusion coefficients with a central (r/a < 0.5) diffusivity {approximately}0.1 m{sup 2}/s that increases rapidly to {approximately}0.3 m{sup 2}/s at r/a = 0.6 and then increases out to the plasma edge as (r/a){sup 2}. These discharges can be satisfactorily modeled without any anomalous convective (pinch) flux. 79 refs., 60 figs.

  5. Fiber optic oxygen sensor using fluorescence quenching for aircraft inerting fuel tank applications

    NASA Astrophysics Data System (ADS)

    Panahi, Allen

    2009-05-01

    On July 18, 2008, the FAA mandated that new aircraft are to include inerting technology to significantly reduce the potential for flammable vapor spaces in center wing fuel tanks. All passenger aircraft constructed since 1991 must also be retrofitted with this technology. This ruling is the result of 18 aircraft that have experienced fuel tank flammable vapor ignition incidents since 1960. Included in these are the TWA 800 and Avianca Flight 203 incidents that resulted in 337 total fatalities. Comprised of heavier hydrocarbon components, jet fuel is much less volatile, with Jet A having a flash point of approximately 100°F and JP-4 having a flash point of approximately 0°F. In contrast, straight-run gasoline has a flash point of approximately -40°F. The flash point is the minimum temperature where a liquid fuel can generate enough vapor to form a flammable mixture with air. If the temperature is below the flash point there isn't enough fuel evaporating to form a flammable fuel-air mixture. Since jet fuel and gasoline have similar flammable concentration limits, gasoline must produce much more vapor at a given temperature to have such a low flash point; hence gasoline is much more volatile than jet fuel. In this paper we explore Fluorescence Technology as applied to the design and development of O2 sensors that can be used for this application and discuss the various test and measurement techniques used to estimate the O2 gas concentration. We compare the various intensity based approaches and contrast them with the frequency domain techniques that measure phase to extract fluorescent lifetimes. The various inerting fuel tank requirements are explained and finally a novel compact measurement system using that uses the frequency heterodyning cross correlation technique that can be used for various applications is described in detail while the benefits are explored together with some test data collected.

  6. 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.

  7. Extending acoustic data measured with small-scale supersonic model jets to practical aircraft exhaust jets

    NASA Astrophysics Data System (ADS)

    Kuo, Ching-Wen

    2010-06-01

    Modern military aircraft jet engines are designed with variable geometry nozzles to provide optimum thrust in different operating conditions within the flight envelope. However, the acoustic measurements for such nozzles are scarce, due to the cost involved in making full-scale measurements and the lack of details about the exact geometry of these nozzles. Thus the present effort at The Pennsylvania State University and the NASA Glenn Research Center, in partnership with GE Aviation, is aiming to study and characterize the acoustic field produced by supersonic jets issuing from converging-diverging military style nozzles. An equally important objective is to develop a scaling methodology for using data obtained from small- and moderate-scale experiments which exhibits the independence of the jet sizes to the measured noise levels. The experimental results presented in this thesis have shown reasonable agreement between small-scale and moderate-scale jet acoustic data, as well as between heated jets and heat-simulated ones. As the scaling methodology is validated, it will be extended to using acoustic data measured with small-scale supersonic model jets to the prediction of the most important components of full-scale engine noise. When comparing the measured acoustic spectra with a microphone array set at different radial locations, the characteristics of the jet noise source distribution may induce subtle inaccuracies, depending on the conditions of jet operation. A close look is taken at the details of the noise generation region in order to better understand the mismatch between spectra measured at various acoustic field radial locations. A processing methodology was developed to correct the effect of the noise source distribution and efficiently compare near-field and far-field spectra with unprecedented accuracy. This technique then demonstrates that the measured noise levels in the physically restricted space of an anechoic chamber can be appropriately

  8. On INM's Use of Corrected Net Thrust for the Prediction of Jet Aircraft Noise

    NASA Technical Reports Server (NTRS)

    McAninch, Gerry L.; Shepherd, Kevin P.

    2011-01-01

    The Federal Aviation Administration s (FAA) Integrated Noise Model (INM) employs a prediction methodology that relies on corrected net thrust as the sole correlating parameter between aircraft and engine operating states and aircraft noise. Thus aircraft noise measured for one set of atmospheric and aircraft operating conditions is assumed to be applicable to all other conditions as long as the corrected net thrust remains constant. This hypothesis is investigated under two primary assumptions: (1) the sound field generated by the aircraft is dominated by jet noise, and (2) the sound field generated by the jet flow is adequately described by Lighthill s theory of noise generated by turbulence.

  9. Jet aircraft engine exhaust emissions database development: Year 1990 and 2015 scenarios

    NASA Technical Reports Server (NTRS)

    Landau, Z. Harry; Metwally, Munir; Vanalstyne, Richard; Ward, Clay A.

    1994-01-01

    Studies relating to environmental emissions associated with the High Speed Civil Transport (HSCT) military jet and charter jet aircraft were conducted by McDonnell Douglas Aerospace Transport Aircraft. The report includes engine emission results for baseline 1990 charter and military scenario and the projected jet engine emissions results for a 2015 scenario for a Mach 1.6 HSCT charter and military fleet. Discussions of the methodology used in formulating these databases are provided.

  10. 19 CFR 10.62b - Aircraft turbine fuel.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... section. Withdrawals under this paragraph shall be annotated with the term “Withdrawal under 19 CFR 10.62b... 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...

  11. 19 CFR 10.62b - Aircraft turbine fuel.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... section. Withdrawals under this paragraph shall be annotated with the term “Withdrawal under 19 CFR 10.62b... 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...

  12. 19 CFR 10.62b - Aircraft turbine fuel.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... section. Withdrawals under this paragraph shall be annotated with the term “Withdrawal under 19 CFR 10.62b... 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...

  13. 19 CFR 10.62b - Aircraft turbine fuel.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... section. Withdrawals under this paragraph shall be annotated with the term “Withdrawal under 19 CFR 10.62b... 19 Customs Duties 1 2010-04-01 2010-04-01 false Aircraft turbine fuel. 10.62b Section 10.62b... Supplies and Equipment for Vessels § 10.62b Aircraft turbine fuel. (a) General. Unless otherwise...

  14. 19 CFR 10.62b - Aircraft turbine fuel.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... section. Withdrawals under this paragraph shall be annotated with the term “Withdrawal under 19 CFR 10.62b... 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...

  15. Exploratory flight investigation of aircraft response to the wing vortex wake generated by the augmentor wing jet STOL research aircraft

    NASA Technical Reports Server (NTRS)

    Jacobsen, R. A.; Drinkwater, F. J., III

    1975-01-01

    A brief exploratory flight program was conducted at Ames Research Center to investigate the vortex wake hazard of a powered-lift STOL aircraft. The study was made by flying an instrumented Cessna 210 aircraft into the wake of the augmentor wing jet STOL research aircraft at separation distances from 1 to 4 n.mi. Characteristics of the wake were evaluated in terms of the magnitude of the upset of the probing aircraft. Results indicated that within 1 n.mi. separation the wake could cause rolling moments in excess of roll control power and yawing moments equivalent to rudder control power of the probe aircraft. Subjective evaluations by the pilots of the Cessna 210 aircraft, supported by response measurements, indicated that the upset caused by the wake of the STOL aircraft was comparable to that of a DC-9 in the landing configuration.

  16. 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.

  17. Physical and chemical behavior of flowing endothermic jet fuels

    NASA Astrophysics Data System (ADS)

    Ward, Thomas Arthur

    Hydrocarbon fuels have been used as cooling media for aircraft jet engines for decades. However, modern aircraft engines are reaching a practical heat transfer limit beyond which the convective heat transfer provided by fuels is no longer adequate. One solution is to use an endothermic fuel that absorbs heat through a series of pyrolytic chemical reactions. However, many of the physical and chemical processes involved in endothermic fuel degradation are not well understood. The purpose of this dissertation is to study different characteristics of endothermic fuels using experiments and computational models. In the first section, data from three flow experiments using heated Jet-A fuel and additives were analyzed (with the aid of CFD calculations) to study the effects of treated surfaces on surface deposition. Surface deposition is the primary impediment in creating an operational endothermic fuel heat exchanger system, because deposits can obstruct fuel pathways causing a catastrophic system failure. As heated fuel flows through a fuel system, trace species within the fuel react with dissolved O2 to form surface deposits. At relatively higher fuel temperatures, the dissolved O2 is depleted, and pyrolytic chemistry becomes dominant (at temperatures greater than ˜500 °C). In the first experiment, the dissolved O2 consumption of heated fuel was measured on different surface types over a range of temperatures. It is found that use of treated tubes significantly delays oxidation of the fuel. In the second experiment, the treated length of tubing was progressively increased, which varied the characteristics of the thermal-oxidative deposits formed. In the third experiment, pyrolytic surface deposition in either fully treated or untreated tubes is studied. It is found that the treated surface significantly reduced the formation of surface deposits for both thermal oxidative and pyrolytic degradation mechanisms. Moreover, it is found that the chemical reactions resulting

  18. Studies of jet fuel thermal stability and oxidation using a quartz crystal microbalance and pressure measurements

    SciTech Connect

    Zabarnick, S. . Aerospace Mechanics Div.)

    1994-05-01

    The thermal stability of aircraft jet fuels was measured in real time with a quartz crystal microbalance (QCM) at 140 C. Qualitative data on the oxidation of these fuels was also obtained by monitoring the system pressure during thermal stressing. The system was operated at relatively low oxygen availability (1 atm air) which more closely approximates the oxygen availability of flowing fuel tests and real fuel systems than previous work. The high sensitivity and good reproducibility of the QCM permitted deposition measurements under unaccelerated conditions (i.e., relatively low temperature and oxygen availability). Correlation of oxidation and deposition behavior provided insight into the deposition and oxidation processes.

  19. 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.

  20. Study of LH2 fueled subsonic passenger transport aircraft

    NASA Technical Reports Server (NTRS)

    Brewer, G. D.; Morris, R. E.

    1976-01-01

    The potential of using liquid hydrogen as fuel in subsonic transport aircraft was investigated to explore an expanded matrix of passenger aircraft sizes. Aircraft capable of carrying 130 passengers 2,780 km (1500 n.mi.); 200 passengers 5,560 km (3000 n.mi.); and 400 passengers on a 9,265 km (5000 n.mi.) radius mission, were designed parametrically. Both liquid hydrogen and conventionally fueled versions were generated for each payload/range in order that comparisons could be made. Aircraft in each mission category were compared on the basis of weight, size, cost, energy utilization, and noise.

  1. Atomization and combustion performance of antimisting kerosene and jet fuel

    NASA Technical Reports Server (NTRS)

    Fleeter, R.; Parikh, P.; Sarohia, V.

    1983-01-01

    Combustion performance of antimisting kerosene (AMK) containing FM-9 polymer was investigated at various levels of degradation (restoration of AMK for normal use in a gas turbine engine). To establish the relationship of degradation and atomization to performance in an aircraft gas turbine combustor, sprays formed by the nozzle of a JT8-D combustor with Jet A and AMK at 1 atmosphere (atm) (14.1 lb/square in absolute) pressure and 22 C at several degradation levels were analyzed. A new spray characterization technique based on digital image analysis of high resolution, wide field spray images formed under pulsed ruby laser sheet illumination was developed. Combustion tests were performed for these fuels in a JT8-D single can combustor facility to measure combustion efficiency and the lean extinction limit. Correlation of combustion performance under simulated engine operating conditions with nozzle spray Sauter mean diameter (SMD) measured at 1 atm and 22 C were observed. Fuel spray SMD and hence the combustion efficiency are strongly influenced by fuel degradation level. Use of even the most highly degraded AMK tested (filter ratio = 1.2) resulted in an increase in fuel consumption of 0.08% to 0.20% at engine cruise conditions.

  2. 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.

  3. Composition of jet fuels from tar oil

    SciTech Connect

    Knudson, C.L.; Willson, W.G.; Miller, D.J.; Ness, R.O. Jr.; Ruud, A. )

    1987-04-01

    Concerns About World Oil Problems are Growing is the title of a recent C and E News article. It notes how the present low oil prices are again resulting in the US increasing its oil imports from 25% to 29% of refinery inputs in the first six months of 1986 compared to 1985, and the October 10 Wall Street Journal estimates that imports could reach 50% by 1990. At the same time, petroleum crudes are becoming heavier. However, heavier crude will not provide the quantity of quality fuels such as aviation turbine fuel by simply taking a distillation cut. The more it becomes necessary to process and upgrade heavy resids to obtain quality fuels, the more competitive fuel from non-petroleum sources will become. In spite of the fact that the technology exists to produce synthetic turbine fuels, the US, with its documented coal and oil shale reserves, has no commercial liquefaction plants. Quite simply, the process economics driven by crude petroleum costs make a grass roots liquefaction plant not competitive. There does exist, however, a coal gasification plant in the US, the Great Plains Gasification Plant (GPGP) at Beulah, North Dakota, which produces quantities of coal liquid by-products during its daily production of 137 MM SCF of synthetic natural gas. The value of these liquids is presently that of a plant fuel. Successful demonstration that coal liquids from GPGP can be processed into jet fuels at a competitive cost may finally result in establishing coal liquids as a viable source for liquid fuel and would also add significant plant revenues. This paper reports on initial work at the University of North Dakota Energy Research Center to upgrade the tar oil, with an ultimate goal of producing aviation turbine fuel.

  4. Production of bio-jet fuel from microalgae

    NASA Astrophysics Data System (ADS)

    Elmoraghy, Marian

    The increase in petroleum-based aviation fuel consumption, the decrease in petroleum resources, the fluctuation of the crude oil price, the increase in greenhouse gas emission and the need for energy security are motivating the development of an alternate jet fuel. Bio-jet fuel has to be a drop in fuel, technically and economically feasible, environmentally friendly, greener than jet fuel, produced locally and low gallon per Btu. Bic jet fuel has been produced by blending petro-based jet fuel with microalgae biodiesel (Fatty Acid Methyl Ester, or simply FAME). Indoor microalgae growth, lipids extraction and transetrification to biodiesel are energy and fresh water intensive and time consuming. In addition, the quality of the biodiesel product and the physical properties of the bio-jet fuel blends are unknown. This work addressed these challenges. Minimizing the energy requirements and making microalgae growth process greener were accomplished by replacing fluorescent lights with light emitting diodes (LEDs). Reducing fresh water footprint in algae growth was accomplished by waste water use. Microalgae biodiesel production time was reduced using the one-step (in-situ transestrification) process. Yields up to 56.82 mg FAME/g dry algae were obtained. Predicted physical properties of in-situ FAME satisfied European and American standards confirming its quality. Lipid triggering by nitrogen deprivation was accomplished in order to increase the FAME production. Bio-jet fuel freezing points and heating values were measured for different jet fuel to biodiesel blend ratios.

  5. 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.

  6. Real-time measurements of jet aircraft engine exhaust.

    PubMed

    Rogers, Fred; Arnott, Pat; Zielinska, Barbara; Sagebiel, John; Kelly, Kerry E; Wagner, David; Lighty, JoAnn S; Sarofim, Adel F

    2005-05-01

    Particulate-phase exhaust properties from two different types of ground-based jet aircraft engines--high-thrust and turboshaft--were studied with real-time instruments on a portable pallet and additional time-integrated sampling devices. The real-time instruments successfully characterized rapidly changing particulate mass, light absorption, and polycyclic aromatic hydrocarbon (PAH) content. The integrated measurements included particulate-size distributions, PAH, and carbon concentrations for an entire test run (i.e., "run-integrated" measurements). In all cases, the particle-size distributions showed single modes peaking at 20-40nm diameter. Measurements of exhaust from high-thrust F404 engines showed relatively low-light absorption compared with exhaust from a turboshaft engine. Particulate-phase PAH measurements generally varied in phase with both net particulate mass and with light-absorbing particulate concentrations. Unexplained response behavior sometimes occurred with the real-time PAH analyzer, although on average the real-time and integrated PAH methods agreed within the same order of magnitude found in earlier investigations.

  7. Real-time measurements of jet aircraft engine exhaust.

    PubMed

    Rogers, Fred; Arnott, Pat; Zielinska, Barbara; Sagebiel, John; Kelly, Kerry E; Wagner, David; Lighty, JoAnn S; Sarofim, Adel F

    2005-05-01

    Particulate-phase exhaust properties from two different types of ground-based jet aircraft engines--high-thrust and turboshaft--were studied with real-time instruments on a portable pallet and additional time-integrated sampling devices. The real-time instruments successfully characterized rapidly changing particulate mass, light absorption, and polycyclic aromatic hydrocarbon (PAH) content. The integrated measurements included particulate-size distributions, PAH, and carbon concentrations for an entire test run (i.e., "run-integrated" measurements). In all cases, the particle-size distributions showed single modes peaking at 20-40nm diameter. Measurements of exhaust from high-thrust F404 engines showed relatively low-light absorption compared with exhaust from a turboshaft engine. Particulate-phase PAH measurements generally varied in phase with both net particulate mass and with light-absorbing particulate concentrations. Unexplained response behavior sometimes occurred with the real-time PAH analyzer, although on average the real-time and integrated PAH methods agreed within the same order of magnitude found in earlier investigations. PMID:15991667

  8. Mathematical Model of the Jet Engine Fuel System

    NASA Astrophysics Data System (ADS)

    Klimko, Marek

    2015-05-01

    The paper discusses the design of a simplified mathematical model of the jet (turbo-compressor) engine fuel system. The solution will be based on the regulation law, where the control parameter is a fuel mass flow rate and the regulated parameter is the rotational speed. A differential equation of the jet engine and also differential equations of other fuel system components (fuel pump, throttle valve, pressure regulator) will be described, with respect to advanced predetermined simplifications.

  9. Certification of an agricultural spray aircraft on ethanol fuel

    SciTech Connect

    Shauck, M.E.; Zanin, M.G.

    1994-12-31

    A Piper Pawnee, one of the most common agricultural spray aircraft, is currently undergoing Federal Aviation Administration (FAA) certification to allow the use of denatured ethanol as its fuel. This certification is part of a broader effort to introduce ethanol as a replacement for aviation gasoline. Various reasons brought about the choice of an agricultural spray aircraft to be certified on ethanol. One is the minimization of initial fuel distribution problems. Agricultural aviation often requires only single fuel storage since most of the flying is local. Additionally, corn-produced ethanol is the natural fuel of choice for farming operations. The increased power developed on ethanol compared to aviation gasoline (avgas) is very important when operating heavily loaded spray aircraft at very low altitudes. The power-plant, a Lycoming IO-540, is already certified. The aircraft is currently flying on ethanol in order to satisfy the airframe requirements. The effort is being supported by a consortium of organizations of corn-producing states. Upon completion of certification, the aircraft will be demonstrated around the mid-western states. Certification will allow the use of the aircraft in the commercial arena. Many mid-western agricultural spray operations and ag-pilots have already expressed interest in converting their aircraft to ethanol fuel.

  10. Investigation of jet fuel thermal stability using photon correlation spectroscopy and a quartz crystal microbalance

    SciTech Connect

    Trott, W.M.

    1995-12-31

    The thermal stability of aviation fuels is an important concern in designs for enhanced aircraft performance. In addition to its primary use as a propellant, jet fuel serves as a coolant for the environmental control system, engine lubrication, avionics, etc. in present military applications. Thermal loads on the fuel are anticipated to increase concurrently with the demands of advanced aircraft. Unfortunately, elevated temperatures in hydrocarbon-based fuels lead to oxidative degradation, producing insoluble products in the bulk liquid as well as deposits on contacting. These processes reduce heat exchanger efficiencies and can result in obstructions of critical components, including valves, filters, and injection nozzles. real-time diagnostics for monmitoring incipient particle formation as well as mass deposition on surfaces is needed. This report describes an experimental assembly designed for simultaneous application of photon correlation spectroscopy and a quartz crystal microbalance. Results from measurements are discussed.

  11. Removal of polar impurities from diesel and jet fuel

    SciTech Connect

    Diaz, Z.; Miller, J.H.

    1990-04-03

    This patent describes a process for the removal of polar impurities in diesel or jet fuel. It comprises: treating the diesel or jet fuel with a non-ionic macroreticular cross-linked acrylic aliphatic ester resin to effect removal of the polar impurities.

  12. Sooting characteristics of surrogates for jet fuels

    SciTech Connect

    Mensch, Amy; Santoro, Robert J.; Litzinger, Thomas A.; Lee, S.-Y.

    2010-06-15

    Currently, modeling the combustion of aviation fuels, such as JP-8 and JetA, is not feasible due to the complexity and compositional variation of these practical fuels. Surrogate fuel mixtures, composed of a few pure hydrocarbon compounds, are a key step toward modeling the combustion of practical aviation fuels. For the surrogate to simulate the practical fuel, the composition must be designed to reproduce certain pre-designated chemical parameters such as sooting tendency, H/C ratio, autoignition, as well as physical parameters such as boiling range and density. In this study, we focused only on the sooting characteristics based on the Threshold Soot Index (TSI). New measurements of TSI values derived from the smoke point along with other sooting tendency data from the literature have been combined to develop a set of recommended TSI values for pure compounds used to make surrogate mixtures. When formulating the surrogate fuel mixtures, the TSI values of the components are used to predict the TSI of the mixture. To verify the empirical mixture rule for TSI, the TSI values of several binary mixtures of candidate surrogate components were measured. Binary mixtures were also used to derive a TSI for iso-cetane, which had not previously been measured, and to verify the TSI for 1-methylnaphthalene, which had a low smoke point and large relative uncertainty as a pure compound. Lastly, surrogate mixtures containing three components were tested to see how well the measured TSI values matched the predicted values, and to demonstrate that a target value for TSI can be maintained using various components, while also holding the H/C ratio constant. (author)

  13. 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.

  14. Fuel conservation merits of advanced turboprop transport aircraft

    NASA Technical Reports Server (NTRS)

    Revell, J. D.; Tullis, R. H.

    1977-01-01

    The advantages of a propfan powered aircraft for the commercial air transportation system were assessed by the comparison with an equivalent turbofan transport. Comparisons were accomplished on the basis of fuel utilization and operating costs, as well as aircraft weight and size. Advantages of the propfan aircraft, concerning fuel utilization and operating costs, were accomplished by considering: (1) incorporation of propfan performance and acoustic data; (2) revised mission profiles (longer design range and reduction in; and cruise speed) (3) utilization of alternate and advanced technology engines.

  15. Decontamination performance of selected in situ technologies for jet fuel contamination. Master's thesis

    SciTech Connect

    Chesley, G.D.

    1993-01-01

    Specific study of jet fuel is warranted because of the quantitive and qualitative component differences between jet fuel and other hydrocarbon fuels. Quantitatively, jet fuel contains a larger aliphatic or saturate fraction and a smaller aromatic fraction than other fuels (i.e. heating oil and diesel oil) in the medium-boiling-point-distillate class of fuels. Since the aliphatic and aromatic fractions of fuel are not equally susceptible to biodegradation, jet fuel decontamination using biodegradation may be different from other fuels.

  16. A jet fuel surrogate formulated by real fuel properties

    SciTech Connect

    Dooley, Stephen; Won, Sang Hee; Chaos, Marcos; Heyne, Joshua; Ju, Yiguang; Dryer, Frederick L.; Kumar, Kamal; Sung, Chih-Jen; Wang, Haowei; Oehlschlaeger, Matthew A.; Santoro, Robert J.; Litzinger, Thomas A.

    2010-12-15

    An implicit methodology based on chemical group theory to formulate a jet aviation fuel surrogate by the measurements of several combustion related fuel properties is tested. The empirical formula and derived cetane number of an actual aviation fuel, POSF 4658, have been determined. A three component surrogate fuel for POSF 4658 has been formulated by constraining a mixture of n-decane, iso-octane and toluene to reproduce the hydrogen/carbon ratio and derived cetane number of the target fuel. The validity of the proposed surrogate is evaluated by experimental measurement of select combustion properties of POSF 4658, and the POSF 4658 surrogate. (1)A variable pressure flow reactor has been used to chart the chemical reactivity of stoichiometric mixtures of POSF 4658/O{sub 2}/N{sub 2} and POSF 4658 surrogate/O{sub 2}/N{sub 2} at 12.5 atm and 500-1000 K, fixing the carbon content at 0.3% for both mixtures. (2)The high temperature chemical reactivity and chemical kinetic-molecular diffusion coupling of POSF 4658 and POSF 4658 surrogate have been evaluated by measurement of the strained extinction limit of diffusion flames. (3)The autoignition behavior of POSF 4658 and POSF 4658 surrogate has been measured with a shock tube at 674-1222 K and with a rapid compression machine at 645-714 K for stoichiometric mixtures of fuel in air at pressures close to 20 atm. The flow reactor study shows that the character and extent of chemical reactivity of both fuels at low temperature (500-675 K) and high temperature (900 K+) are extremely similar. Slight differences in the transition from the end of the negative temperature coefficient regime to hot ignition are observed. The diffusion flame strained extinction limits of the fuels are observed to be indistinguishable when compared on a molar basis. Ignition delay measurements also show that POSF 4658 exhibits NTC behavior. Moreover, the ignition delays of both fuels are also extremely similar over the temperature range studied in

  17. 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.

  18. 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.

  19. Workshop on Jet Exhaust Noise Reduction for Tactical Aircraft - NASA Perspective

    NASA Technical Reports Server (NTRS)

    Huff, Dennis L.; Henderson, Brenda S.

    2007-01-01

    Jet noise from supersonic, high performance aircraft is a significant problem for takeoff and landing operations near air bases and aircraft carriers. As newer aircraft with higher thrust and performance are introduced, the noise tends to increase due to higher jet exhaust velocities. Jet noise has been a subject of research for over 55 years. Commercial subsonic aircraft benefit from changes to the engine cycle that reduce the exhaust velocities and result in significant noise reduction. Most of the research programs over the past few decades have concentrated on commercial aircraft. Progress has been made by introducing new engines with design features that reduce the noise. NASA has recently started a new program called "Fundamental Aeronautics" where three projects (subsonic fixed wing, subsonic rotary wing, and supersonics) address aircraft noise. For the supersonics project, a primary goal is to understand the underlying physics associated with jet noise so that improved noise prediction tools and noise reduction methods can be developed for a wide range of applications. Highlights from the supersonics project are presented including prediction methods for broadband shock noise, flow measurement methods, and noise reduction methods. Realistic expectations are presented based on past history that indicates significant jet noise reduction cannot be achieved without major changes to the engine cycle. NASA s past experience shows a few EPNdB (effective perceived noise level in decibels) can be achieved using low noise design features such as chevron nozzles. Minimal thrust loss can be expected with these nozzles (< 0.5%) and they may be retrofitted on existing engines. In the long term, it is desirable to use variable cycle engines that can be optimized for lower jet noise during takeoff operations and higher thrust for operational performance. It is also suggested that noise experts be included early in the design process for engine nozzle systems to participate

  20. 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. PMID:26495879

  1. 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.

  2. Jet aircraft emissions during cruise: Present and future

    NASA Technical Reports Server (NTRS)

    Grobman, J. S.

    1975-01-01

    Forecasts of engine exhaust emissions that may be practicably achievable for future commercial aircraft operating at high altitude cruise conditions are compared to cruise emission for present day aircraft. The forecasts are based on: (1) knowledge of emission characteristics of combustors and augmentors; (2) combustion research in emission reduction technology, and (3) trends in projected engine designs for advanced subsonic or supersonic commercial aircraft. Recent progress that was made in the evolution of emissions reduction technology is discussed.

  3. Aircraft Engine Exhaust Nozzle System for Jet Noise Reduction

    NASA Technical Reports Server (NTRS)

    Thomas, Russell H. (Inventor); Czech, Michael J. (Inventor); Elkoby, Ronen (Inventor)

    2014-01-01

    The aircraft exhaust engine nozzle system includes a fan nozzle to receive a fan flow from a fan disposed adjacent to an engine disposed above an airframe surface of the aircraft, a core nozzle disposed within the fan nozzle and receiving an engine core flow, and a pylon structure connected to the core nozzle and structurally attached with the airframe surface to secure the engine to the aircraft.

  4. The Buffalo/Spey jet-STOL research aircraft

    NASA Technical Reports Server (NTRS)

    Whittley, D. C.

    1973-01-01

    The program to design and build a Buffalo/Spey Augmentor-Wing research aircraft is presented. The development of an internally blown flap system for the generation of powered lift is discussed. Modification, development, and testing of the Rolls-Royce Spey engine are reported. The ground tests and first flights of the aircraft are described and the application of the internally blown flap concept for short takeoff military transport aircraft is proposed.

  5. Computational fluid dynamics simulations of jet fuel flow near the freeze point temperature

    NASA Astrophysics Data System (ADS)

    Assudani, Rajee

    2006-12-01

    Under low-temperature environmental conditions, the cooling of aircraft fuel results in reduced fluidity with the potential for freezing. Therefore, it is important to study the flow and heat transfer phenomena that occur in an aircraft fuel tank near the freeze point temperature of jet fuels. The purpose of this dissertation is to study the effects of low temperatures on the flow, heat transfer and freezing of commercial and military jet fuels. The research is accomplished with the help of computational models of a thermal simulator tank and a quartz duct. Experimental results with the thermal simulator tank show that fuel flowability and pumpability decrease substantially as temperature is reduced. Time-dependent temperature and velocity distributions were numerically simulated for static cooling. Measured properties were used in all the computational fluid dynamics simulations. The calculations show that stringers, ribs, and other structures strongly promote fuel cooling. Also, the cooler, denser fuel resides near the bottom surface of the fuel tank simulator. The presence of an ullage space within the tank was found to strongly influence the fuel temperature profile by sometimes reducing cooling from the upper surface. Moreover, since the presence of ullage space is an explosion risk, some military aircraft fuel tanks are fitted with explosion suppressant polyurethane foam. To study the effect of foam on the flowability and heat transfer inside the simulator tank, the wing tank thermal simulator was filled with military specified polyurethane foam. The tank was simultaneously drained and cooled and the mass flow rate results showed that flowability of the fuel is not affected by the presence of foam. However, the presence of foam certainly affected the heat transfer phenomenon inside the fuel tank when the simulator tank was cooled and drained simultaneously. To study the freezing behavior of jet fuel under forced flow conditions, a quartz duct was fabricated

  6. Gene expression profiles in the rat central nervous system induced by JP-8 jet fuel vapor exposure.

    PubMed

    Lin, Baochuan; Ritchie, Glenn D; Rossi, John; Pancrazio, Joseph J

    2004-06-17

    Jet propulsion fuel-8 (JP-8) is the predominant fuel for military land vehicles and aircraft used in the US and NATO. Occupational exposure to jet fuel in military personnel has raised concern for the health risk associated with such exposure in the Department of Defense. Clinical studies of humans chronically exposed to jet fuel have suggested both neurotoxicity and neurobehavioral deficits. We utilized rat neurobiology U34 array to measure gene expression changes in whole brain tissue of rats exposed repeatedly to JP-8, under conditions that simulated possible occupational exposure (6 h/day for 91 days) to JP-8 vapor at 250, 500, and 1000 mg/m(3), respectively. Our studies revealed that the gene expression changes of exposure groups can be divided into two main categories according to their functions: (1). neurotransmitter signaling pathways; and (2). stress response. The implications of these gene expression changes are discussed.

  7. 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.

  8. 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... Class 1 and Class 7 § 173.172 Aircraft hydraulic power unit fuel tank. Aircraft hydraulic power unit... for installation as complete units in aircraft are excepted from the specification...

  9. 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

  10. Interactions of Jet Fuels with Nitrile O-Rings: Petroleum-Derived versus Synthetic Fuels

    SciTech Connect

    Gormley, Robert J.; Link, Dirk D.; Baltrus, John P.; Zandhuis, Paul H.

    2009-02-19

    A transition from petroleum-derived jet fuels to blends with Fischer-Tropsch (F-T) fuels, and ultimately fully synthetic hydro-isomerized F-T fuels has raised concern about the fate of plasticizers in nitrile-butadiene rubber o-rings that are contacted by the fuels as this transition occurs. The partitioning of plasticizers and fuel molecules between nitrile o-rings and petroleum-derived, synthetic, and additized-synthetic jet fuels has been measured. Thermal desorption of o-rings soaked in the various jet fuels followed by gas chromatographic analysis with a mass spectrometric detector showed many of the plasticizer and stabilizer compounds were removed from the o-rings regardless of the contact fuel. Fuel molecules were observed to migrate into the o-rings for the petroleum-derived fuel as did both the fuel and additive for a synthetic F-T jet fuel additized with benzyl alcohol, but less for the unadditized synthetic fuel. The specific compounds or classes of compounds involved in the partitioning were identified and a semiquantitative comparison of relative partitioning of the compounds of interest was made, The results provide another step forward in improving the confidence level of using additized, fully synthetic jet fuel in the place of petroleum-derived fuel.

  11. Interactions of Jet Fuels with Nitrile O-Rings: Petroleum-Derived versus Synthetic Fuels

    SciTech Connect

    Gormely, R J; Link, D D; Baltrus, J P; Zandhuis, P H

    2009-01-01

    A transition from petroleum~derived jet fuels to blends with Fischer-Tropsch (F~T) fuels, and ultimately fully synthetic hydro-isomerized F-T fuels has raised concern about the fate of plasticizers in nitrile-butadiene rubber a-rings that are contacted by the fuels as this transition occurs. The partitioning of plasticizers and fuel molecules between nitrile a-rings and petroleum-derived, synthetic, and additized-synthetic jet fuels has been measured. Thermal desorption of o-rings soaked in the various jet fuels followed by gas chromatographic analysis with a mass spectrometric detector showed many of the plasticizer and stabilizer compounds were removed from the o-rings regardless of the contact fuel. Fuel molecules were observed to migrate into the o-rings for the petroleum-derived fuel as did both the fuel and additive for a synthetic F-T jet fuel additized with benzyl alcohol, but less for the unadditized synthetic fuel. The specific compounds or classes of compounds involved in the partitioning were identified and a semiquantitative comparison of relative partitioning of the compounds of interest was made. The results provide another step forward in improving the confidence level of using additized, fully synthetic jet fuel in the place of petroleum-derived fuel.

  12. Interactions of Jet Fuels with Nitrile O-Rings: Petroleum-Derived versus Synthetic Fuels

    SciTech Connect

    Gormley, R.J.; Link, D.D.; Baltrus, J.P.; Zandhuis, P.H.

    2008-01-01

    A transition from petroleum-derived jet fuels to blends with Fischer-Tropsch (F-T) fuels, and ultimately fully synthetic hydro-isomerized F-T fuels has raised concern about the fate of plasticizers in nitrile-butadiene rubber o-rings that are contacted by the fuels as this transition occurs. The partitioning of plasticizers and fuel molecules between nitrile o-rings and petroleum-derived, synthetic, and additized-synthetic jet fuels has been measured. Thermal desorption of o-rings soaked in the various jet fuels followed by gas chromatographic analysis with a mass spectrometric detector showed many of the plasticizer and stabilizer compounds were removed from the o-rings regardless of the contact fuel. Fuel molecules were observed to migrate into the o-rings for the petroleum-derived fuel as did both the fuel and additive for a synthetic F-T jet fuel additized with benzyl alcohol, but less for the unadditized synthetic fuel. The specific compounds or classes of compounds involved in the partitioning were identified and a semiquantitative comparison of relative partitioning of the compounds of interest was made. The results provide another step forward in improving the confidence level of using additized, fuIly synthetic jet fuel in the place of petroleum-derived fueL

  13. Interactions of Jet Fuels with Nitrile O-Rings: Petroleum-Derived versus Synthetic Fuels

    SciTech Connect

    Gormley, Robert J.; Link, Dirk D.; Baltrus, John P.; Zandhuis, Paul H.

    2009-01-01

    A transition from petroleum-derived jet fuels to blends with Fischer-Tropsch (F-T) fuels, and ultimately fully synthetic hydro-isomerized F-T fuels has raised concern about the fate of plasticizers in nitrile-butadiene rubber a-rings that are contacted by the fuels as this transition occurs. The partitioning of plasticizers and fuel molecules between nitrile a-rings and petroleum-derived, synthetic, and additized-synthetic jet fuels has been measured. Thermal desorption of o-rings soaked in the various jet fuels followed by gas chromatographic analysis with a mass spectrometric detector showed many of the plasticizer and stabilizer compounds were removed from the o-rings regardless of the contact fuel. Fuel molecules were observed to migrate into the o-rings for the petroleum-derived fuel as did both the fuel and additive for a synthetic F-T jet fuel additized with benzyl alcohol, but less for the unadditized synthetic fuel. The specific compounds or classes of compounds involved in the partitioning were identified and a semiquantitative comparison of relative partitioning of the compounds of interest was made. The results provide another step forward in improving the confidence level of using additized, fully synthetic jet fuel in the place of petroleum-derived fuel.

  14. Spray Characterization of Gas-to-Liquid Synthetic Jet Fuels

    NASA Astrophysics Data System (ADS)

    Kannaiyan, Kumaran; Sadr, Reza

    2011-11-01

    In the recent years, development of alternative jet fuels is gaining importance owing to the demand for cleaner combustion. In addition to having energy density that matches those of conventional fuels, alternate jet fuels need to possess vital qualities such as rapid atomization and vaporization, quick re-ignition at high altitude, less emission, and poses ease of handling. The fuel preparatory steps (atomization and vaporization) and mixing in a combustion chamber play a crucial role on the subsequent combustion and emission characteristics. Gas-to-Liquid (GTL) synthetic jet fuel obtained from Fischer-Tropsch synthesis has grabbed the global attention due to its cleaner combustion characteristics as a result of the absence of aromatics and sulphur. As a part of an on-going joint effort between Texas A&M at Qatar (TAMUQ), Rolls-Royce (UK), and German Aerospace Laboratory (DLR), a spray characterization experimental facility is set up at TAMUQ to study the spray characteristics of GTL fuel and highlights the influence of change in fuel composition on the spray characteristics. In this work, spray characteristics such as droplet size, velocity, and distribution of different GTL fuel blends is investigated and compared with the spray characteristics of conventional JetA1 fuel. Supported by Qatar Science and Technology Park, QSTP.

  15. 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.

  16. Composition and properties of jet and diesel fuels derived from coal and shale

    NASA Astrophysics Data System (ADS)

    Solash, J.; Hazlett, R. N.

    1981-02-01

    Important properties controlling the availability and efficient use of fuels for Navy aircraft and ships are a) low temperature properties, b) stability, c) combustion behavior, and d) safety. In general, these critical properties are controlled by composition. Therefore, a variety of instrumental analyses-capillary gas chromatography, liquid chromatography, carbon-13 and proton nmr, and electron impact and field ionization mass spectrometry-have been applied to jet and diesel fuels made from coal and shale. The low temperature properties are controlled by n-alkanes and the combustion behavior is degraded by aromatics as well as partially saturated polynuclear arometics. Fuel stability is degraded by sulfur and nitrogen compounds, both of which are prevalent in middle distillate fields derived from a alternative fossil fuel sources.

  17. Pollution reduction technology program for small jet aircraft engines: Class T1

    NASA Technical Reports Server (NTRS)

    Bruce, T. W.; Davis, F. G.; Mongia, H. C.

    1977-01-01

    Small jet aircraft engines (EPA class T1, turbojet and turbofan engines of less than 35.6 kN thrust) were evaluated with the objective of attaining emissions reduction consistent with performance constraints. Configurations employing the technological advances were screened and developed through full scale rig testing. The most promising approaches in full-scale engine testing were evaluated.

  18. 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.

  19. 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.

  20. 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.

  1. Jet fuels of higher volatility: An airline view

    SciTech Connect

    Trimble, M.H.

    1982-05-01

    Use of jet fuels of higher volatility is reviewed by some airlines periodically on a routine basis. Most often, however, airlines become concerned when aviation kerosine supply problems are encountered or anticipated. The purpose of this paper is to discuss the known principles of fuel selection and how they influence airline consideration.

  2. Personal exposure to JP-8 jet fuel vapors and exhaust at air force bases.

    PubMed

    Pleil, J D; Smith, L B; Zelnick, S D

    2000-03-01

    JP-8 jet fuel (similar to commercial/international jet A-1 fuel) is the standard military fuel for all types of vehicles, including the U.S. Air Force aircraft inventory. As such, JP-8 presents the most common chemical exposure in the Air Force, particularly for flight and ground crew personnel during preflight operations and for maintenance personnel performing routine tasks. Personal exposure at an Air Force base occurs through occupational exposure for personnel involved with fuel and aircraft handling and/or through incidental exposure, primarily through inhalation of ambient fuel vapors. Because JP-8 is less volatile than its predecessor fuel (JP-4), contact with liquid fuel on skin and clothing may result in prolonged exposure. The slowly evaporating JP-8 fuel tends to linger on exposed personnel during their interaction with their previously unexposed colleagues. To begin to assess the relative exposures, we made ambient air measurements and used recently developed methods for collecting exhaled breath in special containers. We then analyzed for certain volatile marker compounds for JP-8, as well as for some aromatic hydrocarbons (especially benzene) that are related to long-term health risks. Ambient samples were collected by using compact, battery-operated, personal whole-air samplers that have recently been developed as commercial products; breath samples were collected using our single-breath canister method that uses 1-L canisters fitted with valves and small disposable breathing tubes. We collected breath samples from various groups of Air Force personnel and found a demonstrable JP-8 exposure for all subjects, ranging from slight elevations as compared to a control cohort to > 100 [mutilpe] the control values. This work suggests that further studies should be performed on specific issues to obtain pertinent exposure data. The data can be applied to assessments of health outcomes and to recommendations for changes in the use of personal protective

  3. Integrated coke, asphalt and jet fuel production process and apparatus

    DOEpatents

    Shang, Jer Y.

    1991-01-01

    A process and apparatus for the production of coke, asphalt and jet fuel m a feed of fossil fuels containing volatile carbon compounds therein is disclosed. The process includes the steps of pyrolyzing the feed in an entrained bed pyrolyzing means, separating the volatile pyrolysis products from the solid pyrolysis products removing at least one coke from the solid pyrolysis products, fractionating the volatile pyrolysis products to produce an overhead stream and a bottom stream which is useful as asphalt for road pavement, condensing the overhead stream to produce a condensed liquid fraction and a noncondensable, gaseous fraction, and removing water from the condensed liquid fraction to produce a jet fuel-containing product. The disclosed apparatus is useful for practicing the foregoing process. the process provides a useful method of mass producing and jet fuels from materials such as coal, oil shale and tar sands.

  4. 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.

  5. Passenger Transmitters as A Possible Cause of Aircraft Fuel Ignition

    NASA Technical Reports Server (NTRS)

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

    2006-01-01

    An investigation was performed to study the potential for radio frequency (RF) power radiated from transmitting Portable Electronic Devices (PEDs) to create an arcing/sparking event within the fuel tank of a large transport aircraft. A survey of RF emissions from typical intentional transmitting PEDs was first performed. Aircraft measurements of RF coupling to the fuel tank and its wiring were also performed to determine the PEDs induced power on the wiring, and the re-radiated power within the fuel tank. Laboratory simulations were conducted to determine the required RF power level for an arcing/sparking event. Data analysis shows large positive safety margins, even with simulated faults on the wiring.

  6. Past, present and emerging toxicity issues for jet fuel

    SciTech Connect

    Mattie, David R.

    2011-07-15

    The US Air Force wrote the specification for the first official hydrocarbon-based jet fuel, JP-4, in 1951. This paper will briefly review the toxicity of the current fuel, JP-8, as compared to JP-4. JP-8 has been found to have low acute toxicity with the adverse effects being slight dermal irritation and weak dermal sensitization in animals. JP-4 also has low acute toxicity with slight dermal irritation as the adverse effect. Respiratory tract sensory irritation was greater in JP-8 than in JP-4. Recent data suggest exposure to jet fuel may contribute to hearing loss. Subchronic studies for 90 days with JP-8 and JP-4 showed little toxicity with the primary effect being male rat specific hydrocarbon nephropathy. A 1-year study was conducted for JP-4. The only tumors seen were associated with the male rat specific hydrocarbon nephropathy. A number of immunosuppressive effects have been seen after exposure to JP-8. Limited neurobehavioral effects have been associated with JP-8. JP-8 is not a developmental toxicant and has little reproductive toxicity. JP-4 has not been tested for immune, neurobehavioral or reproductive endpoints. JP-8 and JP-4 were negative in mutagenicity tests but JP-4 showed an increase in unscheduled DNA synthesis. Currently, JP-8 is being used as the standard for comparison of future fuels, including alternative fuels. Emerging issues of concern with jet fuels include naphthalene content, immunotoxicity and inhalation exposure characterization and modeling of complex mixtures such as jet fuels.

  7. Jet Noise Shielding Provided by a Hybrid Wing Body Aircraft

    NASA Technical Reports Server (NTRS)

    Doty, Michael J.; Brooks, Thomas F.; Burley, Casey L.; Bahr, Christopher J.; Pope, Dennis S.

    2014-01-01

    One approach toward achieving NASA's aggressive N+2 noise goal of 42 EPNdB cumulative margin below Stage 4 is through the use of novel vehicle configurations like the Hybrid Wing Body (HWB). Jet noise measurements from an HWB acoustic test in NASA Langley's 14- by 22-Foot Subsonic Tunnel are described. Two dual-stream, heated Compact Jet Engine Simulator (CJES) units are mounted underneath the inverted HWB model on a traversable support to permit measurement of varying levels of shielding provided by the fuselage. Both an axisymmetric and low noise chevron nozzle set are investigated in the context of shielding. The unshielded chevron nozzle set shows 1 to 2 dB of source noise reduction (relative to the unshielded axisymmetric nozzle set) with some penalties at higher frequencies. Shielding of the axisymmetric nozzles shows up to 6.5 dB of reduction at high frequency. The combination of shielding and low noise chevrons shows benefits beyond the expected additive benefits of the two, up to 10 dB, due to the effective migration of the jet source peak noise location upstream for increased shielding effectiveness. Jet noise source maps from phased array results processed with the Deconvolution Approach for the Mapping of Acoustic Sources (DAMAS) algorithm reinforce these observations.

  8. Direct oxidation of jet fuels and Pennsylvania crude oil in a solid oxide fuel cell

    NASA Astrophysics Data System (ADS)

    Zhou, Z. F.; Gallo, C.; Pague, M. B.; Schobert, H.; Lvov, S. N.

    A Cu-ceria solid oxide fuel cell (SOFC) is shown to generate electric power using jet fuels and Pennsylvania crude oil through direct oxidation of the fuels. The liquid fuels contained up to 910 ppm of sulfur and were injected into the anode compartment either with or without N 2 dilution. The performance of the fuel cell was stable over 30 h for jet fuels and Pennsylvania crude oil without N 2 dilution whereas N 2 dilution prolonged the stable power generation up to 100 h for jet fuel and up to 80 h for Pennsylvania crude oil. The generated power density was about 0.1 W cm -2 for both fuels.

  9. [Aviation fuels and aircraft emissions. A risk characterization for airport neighbors using Hamburg Airport as an example].

    PubMed

    Tesseraux, I; Mach, B; Koss, G

    1998-06-01

    Aviation fuels are well characterised regarding their physical and chemical properties. Health effects of fuel vapours and of liquid fuel are described after occupational exposure and in animal studies. Exposure of the general population (airport visitors and people living in the vicinity of airports) may occur during fuel supply particularly in warm summers (odour). Aircraft emissions vary with the engine type and the kind of fuel. Combustion of aviation fuel results in CO2, H2O, CO, C, NOx and a great number of organic compounds. Among the emitted polyaromatic hydrocarbons (PAH) no compound characteristic for jet engines (tracer) could be detected so far. Hardly any data exist on the toxicology of jet engine emissions. According to analyses of their chemical composition, however, they contain various toxicologically relevant compounds including carcinogenic substances. Measurements in ambient air around the Hamburg Airport show no elevated pollutant levels. However, no such data exist on aldehydes, black smoke or fine particles. Annoying odours have been stated in some areas around the airport, which were mainly attributed to the aircraft engine emissions rather than to fuel vapours.

  10. [Aviation fuels and aircraft emissions. A risk characterization for airport neighbors using Hamburg Airport as an example].

    PubMed

    Tesseraux, I; Mach, B; Koss, G

    1998-06-01

    Aviation fuels are well characterised regarding their physical and chemical properties. Health effects of fuel vapours and of liquid fuel are described after occupational exposure and in animal studies. Exposure of the general population (airport visitors and people living in the vicinity of airports) may occur during fuel supply particularly in warm summers (odour). Aircraft emissions vary with the engine type and the kind of fuel. Combustion of aviation fuel results in CO2, H2O, CO, C, NOx and a great number of organic compounds. Among the emitted polyaromatic hydrocarbons (PAH) no compound characteristic for jet engines (tracer) could be detected so far. Hardly any data exist on the toxicology of jet engine emissions. According to analyses of their chemical composition, however, they contain various toxicologically relevant compounds including carcinogenic substances. Measurements in ambient air around the Hamburg Airport show no elevated pollutant levels. However, no such data exist on aldehydes, black smoke or fine particles. Annoying odours have been stated in some areas around the airport, which were mainly attributed to the aircraft engine emissions rather than to fuel vapours. PMID:9686444

  11. Jet engine exhaust emissions of high altitude commercial aircraft projected to 1990

    NASA Technical Reports Server (NTRS)

    Grobman, J.; Ingebo, R. D.

    1974-01-01

    Projected minimum levels of engine exhaust emissions that may be practicably achievable for future commercial aircraft operating at high-altitude cruise conditions are presented. The forecasts are based on:(1) current knowledge of emission characteristics of combustors and augmentors; (2) the status of combustion research in emission reduction technology; and (3) predictable trends in combustion systems and operating conditions as required for projected engine designs that are candidates for advanced subsonic or supersonic commercial aircraft fueled by either JP fuel, liquefied natural gas, or hydrogen. Results are presented for cruise conditions in terms of both an emission index (g constituent/kg fuel) and an emission rate (g constituent/hr).

  12. Thermal Stability Testing of a Fischer-Tropsch Fuel and Various Blends with Jet A

    NASA Technical Reports Server (NTRS)

    Klettlinger, Jennifer Suder; Surgenor, Angela; Yen, Chia

    2010-01-01

    Fischer-Tropsch (F-T) jet fuel composition differs from petroleum-based, conventional commercial jet fuel because of differences in feedstock and production methodology. Fischer-Tropsch fuel typically has a lower aromatic and sulfur content and consists primarily of iso and normal parafins. The ASTM D3241 specification for Jet Fuel Thermal Oxidation Test (JFTOT) break point testing method was used to test the breakpoint of a baseline conventional Jet A, a commercial grade F-T jet fuel, and various blends of this F-T fuel in Jet A. The testing completed in this report was supported by the NASA Fundamental Aeronautics Subsonics Fixed Wing Project.

  13. Aircraft fuel tank slosh and vibration test

    NASA Astrophysics Data System (ADS)

    Zimmermann, H.

    1981-12-01

    A dynamic qualification test for a subsonic and a supersonic external drop tank for a European fighter is presented. The test rig and the specimens are described and the measuring results are discussed. It is shown that for the supersonic tank as well as for the subsonic tank a certain slosh angle an eigenfrequency of the rig increases the amplitudes at the excitation position and the accelerations on the tank. For the subsonic tank it seems that an eigenfrequency is excited for the nose down position of the tank. The qualification requirements are examined. It is proposed that instead of using an arbitrary vibration amplitude and frequency for excitation, frequency ranges and amplitudes which are averaged out of flight measurements at the tank attachment points on the aircraft be used and that the demand for a certain input amplitude at the top of the attachment bulkheads and an output amplitude at the bottom of the attachment bulkheads be deleted.

  14. V/STOL aircraft and the problem of jet-induced suckdown

    NASA Technical Reports Server (NTRS)

    Carlisle, Cherianne

    1988-01-01

    The suckdown condition encountered when jet propelled, Vertical/Short Takeoff and Landing aircraft hover near the ground is described. A discussion of this ground effect problem and how it is being investigated is followed by a more detailed description of one of the methods researchers are using to investigate the basic mechanisms that influence the suckdown condition. Specific parameters that are taken into account include the height of the jet above the ground, jet exit conditions, and model geometry. Data from a current investigation is presented along with some conclusions from other recent investigations in order to relate the significance of some of the parameters influencing suckdown. Suggestions are made for additional testing methods which might be useful to researchers investigating the mechanisms involved in jet induced suckdown.

  15. Perceived Noise Analysis for Offset Jets Applied to Commercial Supersonic Aircraft

    NASA Technical Reports Server (NTRS)

    Huff, Dennis L.; Henderson, Brenda S.; Berton, Jeffrey J.; Seidel, Jonathan A.

    2016-01-01

    A systems analysis was performed with experimental jet noise data, engine/aircraft performance codes and aircraft noise prediction codes to assess takeoff noise levels and mission range for conceptual supersonic commercial aircraft. A parametric study was done to identify viable engine cycles that meet NASA's N+2 goals for noise and performance. Model scale data from offset jets were used as input to the aircraft noise prediction code to determine the expected sound levels for the lateral certification point where jet noise dominates over all other noise sources. The noise predictions were used to determine the optimal orientation of the offset nozzles to minimize the noise at the lateral microphone location. An alternative takeoff procedure called "programmed lapse rate" was evaluated for noise reduction benefits. Results show there are two types of engines that provide acceptable mission range performance; one is a conventional mixed-flow turbofan and the other is a three-stream variable-cycle engine. Separate flow offset nozzles reduce the noise directed toward the thicker side of the outer flow stream, but have less benefit as the core nozzle pressure ratio is reduced. At the systems level for a three-engine N+2 aircraft with full throttle takeoff, there is a 1.4 EPNdB margin to Chapter 3 noise regulations predicted for the lateral certification point (assuming jet noise dominates). With a 10% reduction in thrust just after clearing the runway, the margin increases to 5.5 EPNdB. Margins to Chapter 4 and Chapter 14 levels will depend on the cumulative split between the three certification points, but it appears that low specific thrust engines with a 10% reduction in thrust (programmed lapse rate) can come close to meeting Chapter 14 noise levels. Further noise reduction is possible with engine oversizing and derated takeoff, but more detailed mission studies are needed to investigate the range impacts as well as the practical limits for safety and takeoff

  16. Urinary biomarkers of exposure to jet fuel (JP-8).

    PubMed Central

    Serdar, Berrin; Egeghy, Peter P; Waidyanatha, Suramya; Gibson, Roger; Rappaport, Stephen M

    2003-01-01

    Benzene, naphthalene, and 1- and 2-naphthol were measured in urine samples obtained from 322 U.S. Air Force personnel categorized a priori as likely to have low, moderate, or high exposure to jet fuel [jet propulsion fuel-8 (JP-8)]. In postexposure samples, levels of these analytes in the high-exposure group were 3- to 29-fold greater than in the low-exposure group and 2- to 12-fold greater than in the moderate-exposure group. Heavy exposure to JP-8 contributed roughly the same amount of benzene and more than three times the amount of naphthalene compared with cigarette smoking. Strong correlations were observed among postexposure levels of naphthalene-based biomarkers in urine and naphthalene in air and breath. We conclude that urinary naphthalene and the naphthols can serve as biomarkers of exposure to jet fuel. Of these, the naphthols are probably more useful because of their greater abundance and slower elimination kinetics. PMID:14594628

  17. Thermal Stability of Jet Fuels: Kinetics of Forming Deposit Precursors

    NASA Technical Reports Server (NTRS)

    Naegeli, David W.

    1997-01-01

    The focus of this study was on the autoxidation kinetics of deposit precursor formation in jet fuels. The objectives were: (1) to demonstrate that laser-induced fluorescence is a viable kinetic tool for measuring rates of deposit precursor formation in jet fuels; (2) to determine global rate expressions for the formation of thermal deposit precursors in jet fuels; and (3) to better understand the chemical mechanism of thermal stability. The fuels were isothermally stressed in small glass ampules in the 120 to 180 C range. Concentrations of deposit precursor, hydroperoxide and oxygen consumption were measured over time in the thermally stressed fuels. Deposit precursors were measured using laser-induced fluorescence (LIF), hydroperoxides using a spectrophotometric technique, and oxygen consumption by the pressure loss in the ampule. The expressions, I.P. = 1.278 x 10(exp -11)exp(28,517.9/RT) and R(sub dp) = 2.382 x 10(exp 17)exp(-34,369.2/RT) for the induction period, I.P. and rate of deposit precursor formation R(sub dp), were determined for Jet A fuel. The results of the study support a new theory of deposit formation in jet fuels, which suggest that acid catalyzed ionic reactions compete with free radical reactions to form deposit precursors. The results indicate that deposit precursors form only when aromatics are present in the fuel. Traces of sulfur reduce the rate of autoxidation but increase the yield of deposit precursor. Free radical chemistry is responsible for hydroperoxide formation and the oxidation of sulfur compounds to sulfonic acids. Phenols are then formed by the acid catalyzed decomposition of benzylic hydroperoxides, and deposit precursors are produced by the reaction of phenols with aldehydes, which forms a polymer similar to Bakelite. Deposit precursors appear to have a phenolic resin-like structure because the LIF spectra of the deposit precursors were similar to that of phenolic resin dissolved in TAM.

  18. VTOL in ground effect flows for closely spaced jets. [to predict pressure and upwash forces on aircraft structures

    NASA Technical Reports Server (NTRS)

    Migdal, D.; Hill, W. G., Jr.; Jenkins, R. C.

    1979-01-01

    Results of a series of in ground effect twin jet tests are presented along with flow models for closely spaced jets to help predict pressure and upwash forces on simulated aircraft surfaces. The isolated twin jet tests revealed unstable fountains over a range of spacings and jet heights, regions of below ambient pressure on the ground, and negative pressure differential in the upwash flow field. A separate computer code was developed for vertically oriented, incompressible jets. This model more accurately reflects fountain behavior without fully formed wall jets, and adequately predicts ground isobars, upwash dynamic pressure decay, and fountain lift force variation with height above ground.

  19. Determination of total and polycyclic aromatic hydrocarbons in aviation jet fuel.

    PubMed

    Bernabei, M; Reda, R; Galiero, R; Bocchinfuso, G

    2003-01-24

    The aviation jet fuel widely used in turbine engine aircraft is manufactured from straight-run kerosene. The combustion quality of jet fuel is largely related to the hydrocarbon composition of the fuel itself; paraffins have better burning properties than aromatic compounds, especially naphthalenes and light polycyclic aromatic hydrocarbons (PAHs), which are characterised as soot and smoke producers. For this reason the burning quality of fuel is generally measured as smoke fermation. This evaluation is carried out with UV spectrophotometric determination of total naphthalene hydrocarbons and a chromatographic analysis to determine the total aromatic compounds. These methods can be considered insufficient to evaluate the human health impact of these compounds due to their inability to measure trace (ppm) amounts of each aromatic hyrcarbon and each PAH in accordance with limitations imposed because of their toxicological properties. In this paper two analytical methods are presented. Both are based on a gas chromatographic technique with a mass detector operating in be selected ion monitoring mode. The first method was able to determine more than 60 aromatic hydrocarbons in a fuel sample in a 35-min chromatographic run, while the second was able to carry out the analysis of more than 30 PAHs in a 40-min chromatographic run. The linearity and sensitivity of the methods in measuring these analytes at trace levels are described.

  20. 49 CFR 173.172 - Aircraft hydraulic power unit fuel tank.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 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...

  1. 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... Class 1 and Class 7 § 173.172 Aircraft hydraulic power unit fuel tank. Aircraft hydraulic power unit... consist of an aluminum pressure vessel made from tubing and having welded heads. Primary containment...

  2. 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%.

  3. Similarity spectra analysis of high-performance jet aircraft noise.

    PubMed

    Neilsen, Tracianne B; Gee, Kent L; Wall, Alan T; James, Michael M

    2013-04-01

    Noise measured in the vicinity of an F-22A Raptor has been compared to similarity spectra found previously to represent mixing noise from large-scale and fine-scale turbulent structures in laboratory-scale jet plumes. Comparisons have been made for three engine conditions using ground-based sideline microphones, which covered a large angular aperture. Even though the nozzle geometry is complex and the jet is nonideally expanded, the similarity spectra do agree with large portions of the measured spectra. Toward the sideline, the fine-scale similarity spectrum is used, while the large-scale similarity spectrum provides a good fit to the area of maximum radiation. Combinations of the two similarity spectra are shown to match the data in between those regions. Surprisingly, a combination of the two is also shown to match the data at the farthest aft angle. However, at high frequencies the degree of congruity between the similarity and the measured spectra changes with engine condition and angle. At the higher engine conditions, there is a systematically shallower measured high-frequency slope, with the largest discrepancy occurring in the regions of maximum radiation.

  4. Similarity spectra analysis of high-performance jet aircraft noise.

    PubMed

    Neilsen, Tracianne B; Gee, Kent L; Wall, Alan T; James, Michael M

    2013-04-01

    Noise measured in the vicinity of an F-22A Raptor has been compared to similarity spectra found previously to represent mixing noise from large-scale and fine-scale turbulent structures in laboratory-scale jet plumes. Comparisons have been made for three engine conditions using ground-based sideline microphones, which covered a large angular aperture. Even though the nozzle geometry is complex and the jet is nonideally expanded, the similarity spectra do agree with large portions of the measured spectra. Toward the sideline, the fine-scale similarity spectrum is used, while the large-scale similarity spectrum provides a good fit to the area of maximum radiation. Combinations of the two similarity spectra are shown to match the data in between those regions. Surprisingly, a combination of the two is also shown to match the data at the farthest aft angle. However, at high frequencies the degree of congruity between the similarity and the measured spectra changes with engine condition and angle. At the higher engine conditions, there is a systematically shallower measured high-frequency slope, with the largest discrepancy occurring in the regions of maximum radiation. PMID:23556581

  5. Comparison of cosmic rays radiation detectors on-board commercial jet aircraft.

    PubMed

    Kubančák, Ján; Ambrožová, Iva; Brabcová, Kateřina Pachnerová; Jakůbek, Jan; Kyselová, Dagmar; Ploc, Ondřej; Bemš, Július; Štěpán, Václav; Uchihori, Yukio

    2015-06-01

    Aircrew members and passengers are exposed to increased rates of cosmic radiation on-board commercial jet aircraft. The annual effective doses of crew members often exceed limits for public, thus it is recommended to monitor them. In general, the doses are estimated via various computer codes and in some countries also verified by measurements. This paper describes a comparison of three cosmic rays detectors, namely of the (a) HAWK Tissue Equivalent Proportional Counter; (b) Liulin semiconductor energy deposit spectrometer and (c) TIMEPIX silicon semiconductor pixel detector, exposed to radiation fields on-board commercial Czech Airlines company jet aircraft. Measurements were performed during passenger flights from Prague to Madrid, Oslo, Tbilisi, Yekaterinburg and Almaty, and back in July and August 2011. For all flights, energy deposit spectra and absorbed doses are presented. Measured absorbed dose and dose equivalent are compared with the EPCARD code calculations. Finally, the advantages and disadvantages of all detectors are discussed.

  6. Comparison of cosmic rays radiation detectors on-board commercial jet aircraft.

    PubMed

    Kubančák, Ján; Ambrožová, Iva; Brabcová, Kateřina Pachnerová; Jakůbek, Jan; Kyselová, Dagmar; Ploc, Ondřej; Bemš, Július; Štěpán, Václav; Uchihori, Yukio

    2015-06-01

    Aircrew members and passengers are exposed to increased rates of cosmic radiation on-board commercial jet aircraft. The annual effective doses of crew members often exceed limits for public, thus it is recommended to monitor them. In general, the doses are estimated via various computer codes and in some countries also verified by measurements. This paper describes a comparison of three cosmic rays detectors, namely of the (a) HAWK Tissue Equivalent Proportional Counter; (b) Liulin semiconductor energy deposit spectrometer and (c) TIMEPIX silicon semiconductor pixel detector, exposed to radiation fields on-board commercial Czech Airlines company jet aircraft. Measurements were performed during passenger flights from Prague to Madrid, Oslo, Tbilisi, Yekaterinburg and Almaty, and back in July and August 2011. For all flights, energy deposit spectra and absorbed doses are presented. Measured absorbed dose and dose equivalent are compared with the EPCARD code calculations. Finally, the advantages and disadvantages of all detectors are discussed. PMID:25979739

  7. Measurement and correlation of jet fuel viscosities at low temperatures

    NASA Technical Reports Server (NTRS)

    Schruben, D. L.

    1985-01-01

    Apparatus and procedures were developed to measure jet fuel viscosity for eight current and future jet fuels at temperatures from ambient to near -60 C by shear viscometry. Viscosity data showed good reproducibility even at temperatures a few degrees below the measured freezing point. The viscosity-temperature relationship could be correlated by two linear segments when plotted as a standard log-log type representation (ASTM D 341). At high temperatures, the viscosity-temperature slope is low. At low temperatures, where wax precipitation is significant, the slope is higher. The breakpoint between temperature regions is the filter flow temperature, a fuel characteristic approximated by the freezing point. A generalization of the representation for the eight experimental fuels provided a predictive correlation for low-temperature viscosity, considered sufficiently accurate for many design or performance calculations.

  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. Raptor responses to low-level jet aircraft and sonic booms.

    PubMed

    Ellis, D H; Ellis, C H; Mindell, D P

    1991-01-01

    We estimated effects of low-level military jet aircraft and mid- to high-altitude sonic booms (actual and simulated) on nesting peregrine falcons (Falco peregrinus) and seven other raptors by observing their responses to test stimuli, determining nesting success for the test year, and evaluating site reoccupancy rates for the year following the tests. Frequent and nearby jet aircraft passes: (1) sometimes noticeably alarmed birds, (2) occasionally caused birds to fly from perches or eyries, (3) most often evoked only minimal responses, and (4) were never associated with reproductive failure. Similarly, responses to real and simulated mid- to high-altitude sonic booms were often minimal and never appeared productivity limiting. Eighteen (95%) of 19 nest sites subjected to low-level jet flights and/or simulated sonic booms in 1980 fledged young during that year. Eighteen (95%) of 19 sites disturbed in 1980 were reoccupied by pairs or lone birds of the same species in 1981. We subjected four pairs of prairie falcons (Falco mexicanus) to low-level aircraft at ad libitum levels during the courtship and incubation phases when adults were most likely to abandon: all four eyries fledged young. From heart rate (HR) data taken via a telemetering egg at another prairie falcon eyrie, we determined that stimulus-induced HR alterations were comparable to rate changes for birds settling to incubate following flight. While encouraging, our findings cannot be taken as conclusive evidence that jet flights and/or sonic booms will have no long-term negative effects for other raptor species or for other areas. In addition, we did not experiment with totally naive wild adults, rotary-winged aircraft, or low-level sonic booms. PMID:15092075

  10. Raptor responses to low-level jet aircraft and sonic booms

    USGS Publications Warehouse

    Ellis, D.H.; Ellis, C.H.; Mindell, D.P.

    1991-01-01

    We estimated effects of low-level military jet aircraft and mid- to high-altitude sonic booms (actual and simulated) on nesting peregrine falcons (Falco peregrinus) and seven other raptors by observing their responses to test stimuli, determining nesting success for the test year, and evaluating site reoccupancy rates for the year following the tests. Frequent and nearby jet aircraft passes: (1) sometimes noticeably alarmed birds, (2) occasionally caused birds toffy from perches or eyries, (3) most often evoked only minimal responses, and (4) were never associated with reproductive failure. Similarly, responses to real and simulated mid- to high-altitude sonic booms were often minimal and never appeared productivity limiting. Eighteen (95%) of 19 nest sites subjected to low-level jet flights and/or simulated sonic booms in 1980 fledged young during that year. Eighteen (95%) of l9 sites disturbed in 1980 were reoccupied by pairs or lone birds of the same species in 1981. We subjected four pairs of prairie falcons (Falco mexicanus) to low-level aircraft at ad libitum levels during the courtship and incubation phases when adults were most likely to abandon: all four eyries fledged young. From heart rate (HR) data taken via a telemetering egg at another prairie falcon eyrie, we determined that stimulus-induced HR alterations were comparable to rate changes for birds settling to incubate following flight. While encouraging, our findings cannot be taken as conclusive evidence that jet flights and/or sonic booms will have no long-term negative effects for other raptor species or for other areas. In addition, we did not experiment with totally naive wild adults, rotary-winged aircraft, or low-level sonic booms.

  11. Acoustic intensity near a high-powered military jet aircraft.

    PubMed

    Stout, Trevor A; Gee, Kent L; Neilsen, Tracianne B; Wall, Alan T; James, Michael M

    2015-07-01

    The spatial variation in vector acoustic intensity has been calculated between 100 and 3000 Hz near a high-performance military aircraft. With one engine of a tethered F-22A Raptor operating at military power, a tetrahedral intensity probe was moved to 27 locations in the geometric near and mid-fields to obtain the frequency-dependent intensity vector field. The angles of the maximum intensity region rotate from aft to sideline with increasing frequency, becoming less directional above 800 Hz. Between 100 and 400 Hz, which are principal radiation frequencies, the ray-traced dominant source region rapidly contracts and moves upstream, approaching nearly constant behavior by 1000 Hz. PMID:26233049

  12. Acoustic intensity near a high-powered military jet aircraft.

    PubMed

    Stout, Trevor A; Gee, Kent L; Neilsen, Tracianne B; Wall, Alan T; James, Michael M

    2015-07-01

    The spatial variation in vector acoustic intensity has been calculated between 100 and 3000 Hz near a high-performance military aircraft. With one engine of a tethered F-22A Raptor operating at military power, a tetrahedral intensity probe was moved to 27 locations in the geometric near and mid-fields to obtain the frequency-dependent intensity vector field. The angles of the maximum intensity region rotate from aft to sideline with increasing frequency, becoming less directional above 800 Hz. Between 100 and 400 Hz, which are principal radiation frequencies, the ray-traced dominant source region rapidly contracts and moves upstream, approaching nearly constant behavior by 1000 Hz.

  13. Computational models for the viscous/inviscid analysis of jet aircraft exhaust plumes. [predicting afterbody drag

    NASA Technical Reports Server (NTRS)

    Dash, S. M.; Pergament, H. S.; Thorpe, R. D.

    1980-01-01

    Computational models which analyze viscous/inviscid flow processes in jet aircraft exhaust plumes are discussed. These models are component parts of an NASA-LaRC method for the prediction of nozzle afterbody drag. Inviscid/shock processes are analyzed by the SCIPAC code which is a compact version of a generalized shock capturing, inviscid plume code (SCIPPY). The SCIPAC code analyzes underexpanded jet exhaust gas mixtures with a self-contained thermodynamic package for hydrocarbon exhaust products and air. A detailed and automated treatment of the embedded subsonic zones behind Mach discs is provided in this analysis. Mixing processes along the plume interface are analyzed by two upgraded versions of an overlaid, turbulent mixing code (BOAT) developed previously for calculating nearfield jet entrainment. The BOATAC program is a frozen chemistry version of BOAT containing the aircraft thermodynamic package as SCIPAC; BOATAB is an afterburning version with a self-contained aircraft (hydrocarbon/air) finite-rate chemistry package. The coupling of viscous and inviscid flow processes is achieved by an overlaid procedure with interactive effects accounted for by a displacement thickness type correction to the inviscid plume interface.

  14. Gust response of commercial jet aircraft including effects of autopilot operation

    NASA Technical Reports Server (NTRS)

    Goldberg, J. H.

    1982-01-01

    A simplified theory of aircraft vertical acceleration gust response based on a model including pitch, vertical displacement and control motions due to autopilot operation is presented. High-order autopilot transfer functions are utilized for improved accuracy in the determination of the overall response characteristics. Four representative commercial jet aircraft were studied over a wide range of operating conditions and comparisons of individual responses are given. It is shown that autopilot operation relative to the controls fixed case causes response attenuation of from 10 percent to approximately 25 percent depending on flight condition and increases in crossing number up to 30 percent, with variations between aircraft of from 5 percent to 10 percent, in general, reflecting the differences in autopilot design. A detailed computer program description and listing of the calculation procedure suitable for the general application of the theory to any airplane autopilot combination is also included.

  15. The role of nonlinear effects in the propagation of noise from high-power jet aircraft.

    PubMed

    Gee, Kent L; Sparrow, Victor W; James, Michael M; Downing, J Micah; Hobbs, Christopher M; Gabrielson, Thomas B; Atchley, Anthony A

    2008-06-01

    To address the question of the role of nonlinear effects in the propagation of noise radiated by high-power jet aircraft, extensive measurements were made of the F-22A Raptor during static engine run-ups. Data were acquired at low-, intermediate-, and high-thrust engine settings with microphones located 23-305 m from the aircraft along several angles. Comparisons between the results of a generalized-Burgers-equation-based nonlinear propagation model and the measurements yield favorable agreement, whereas application of a linear propagation model results in spectral predictions that are much too low at high frequencies. The results and analysis show that significant nonlinear propagation effects occur for even intermediate-thrust engine conditions and at angles well away from the peak radiation angle. This suggests that these effects are likely to be common in the propagation of noise radiated by high-power aircraft.

  16. Venturi air-jet vacuum ejectors for high-volume atmospheric sampling on aircraft platforms

    NASA Technical Reports Server (NTRS)

    Hill, Gerald F.; Sachse, Glen W.; Young, Douglas C.; Wade, Larry O.; Burney, Lewis G.

    1992-01-01

    Documentation of the installation and use of venturi air-jet vacuum ejectors for high-volume atmospheric sampling on aircraft platforms is presented. Information on the types of venturis that are useful for meeting the pumping requirements of atmospheric-sampling experiments is also presented. A description of the configuration and installation of the venturi system vacuum line is included with details on the modifications that were made to adapt a venturi to the NASA Electra aircraft at GSFC, Wallops Flight Facility. Flight test results are given for several venturis with emphasis on applications to the Differential Absorption Carbon Monoxide Measurement (DACOM) system at LaRC. This is a source document for atmospheric scientists interested in using the venturi systems installed on the NASA Electra or adapting the technology to other aircraft.

  17. Business Jet

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The Citation Jet, developed by Cessna Aircraft Company, Wichita, KS, is the first business jet to employ Langley Research Center's natural laminar flow (NLF) technology. NLF reduces drag and therefore saves fuel by using only the shape of the wing to keep the airflow smooth, or laminar. This reduces friction between the air and wing, and therefore, reduces drag. NASA's Central Industrial Applications Center, Rural Enterprises, Inc., Durant, OK, its Kansas affiliate, and Wichita State University assisted in the technology transfer.

  18. Comparison of advanced turboprop and conventional jet and propeller aircraft flyover noise annoyance: Preliminary results

    NASA Technical Reports Server (NTRS)

    Mccurdy, D. A.

    1985-01-01

    A laboratory experiment was conducted to compare the flyover noise annoyance of proposed advanced turboprop aircraft with that of conventional turboprop and jet aircraft. The effects of fundamental frequency and tone-to-broadband noise ratio on advanced turboprop annoyance were also examined. A computer synthesis system is used to generate 18 realistic, time varying simulations of propeller aircraft takeoff noise in which the harmonic content is systematically varied to represent the factorial combinations of six fundamental frequencies ranging from 67.5 Hz to 292.5 Hz and three tone-to-broadband noise ratios of 0, 15, and 30 dB. These advanced turboprop simulations along with recordings of five conventional turboprop takeoffs and five conventional jet takeoffs are presented at D-weighted sound pressure levels of 70, 80, and 90 dB to 32 subjects in an anechoic chamber. Analyses of the subjects' annoyance judgments compare the three categories of aircraft and examine the effects of the differences in harmonic content among the advanced turboprop noises. The annoyance prediction ability of various noise measurement procedures and corrections is also examined.

  19. Comparison of advanced turboprop and conventional jet and propeller aircraft flyover noise annoyance - Preliminary results

    NASA Technical Reports Server (NTRS)

    Mccurdy, D. A.

    1985-01-01

    A laboratory experiment was conducted to compare the flyover noise annoyance of proposed advanced turboprop aircraft with that of conventional turboprop and jet aircraft. The effects of fundamental frequency and tone-to-broadband noise ratio on advanced turboprop annoyance were also examined. A computer synthesis system was used to generate 18 realistic, time varyring simulations of propeller aircraft takeoff noise in which the harmonic content was systematically varied to represent the factorial combinations of six fundamental frequencies ranging from 67.5 Hz to 292.5 Hz and three tone-to-broadband noise ratios of 0, 15, and 30 dB. These advanced turboprop simulations along with recordings of five conventional turboprop takeoffs and five conventional jet takeoffs were presented at D-weighted sound pressure levels of 70, 80, and 90 dB to 32 subjects in an anechoic chamber. Analyses of the subjects' annoyance judgments compare the three categories of aircraft and examine the effects of the differences in harmonic content among the advanced turboprop noises. The annoyance prediction ability of various noise measurement procedures and corrections is also examined.

  20. Impact of aviation non-CO₂ combustion effects on the environmental feasibility of alternative jet fuels.

    PubMed

    Stratton, Russell W; Wolfe, Philip J; Hileman, James I

    2011-12-15

    Alternative fuels represent a potential option for reducing the climate impacts of the aviation sector. The climate impacts of alternatives fuel are traditionally considered as a ratio of life cycle greenhouse gas (GHG) emissions to those of the displaced petroleum product; however, this ignores the climate impacts of the non-CO(2) combustion effects from aircraft in the upper atmosphere. The results of this study show that including non-CO(2) combustion emissions and effects in the life cycle of a Synthetic Paraffinic Kerosene (SPK) fuel can lead to a decrease in the relative merit of the SPK fuel relative to conventional jet fuel. For example, an SPK fuel option with zero life cycle GHG emissions would offer a 100% reduction in GHG emissions but only a 48% reduction in actual climate impact using a 100-year time window and the nominal climate modeling assumption set outlined herein. Therefore, climate change mitigation policies for aviation that rely exclusively on relative well-to-wake life cycle GHG emissions as a proxy for aviation climate impact may overestimate the benefit of alternative fuel use on the global climate system.

  1. Military jet fuel from shale oil

    NASA Technical Reports Server (NTRS)

    Coppola, E. N.

    1980-01-01

    Investigations leading to a specification for aviation turbine fuel produced from whole crude shale oil are described. Refining methods involving hydrocracking, hydrotreating, and extraction processes are briefly examined and their production capabilities are assessed.

  2. Stabilization of T-6 jet fuel by mixtures of antioxidants

    SciTech Connect

    Golubeva, I.A.; Gutnikova, L.P.; Popova, T.V.; Vishnyakova, T.P.

    1985-09-01

    Work has been reported on synergistic combinations of additives for the stabilization of jet fuels. This paper investigates combinations of the additive KF-1 with dilauryl thiodipropionate (DLTDP). Data on the effects of these additive combinations on the post-test optical density, acidity and peroxide number of T-6 fuel is presented. Attention is also given to combinations of antioxidants with organometallic compounds. The stabilization of T-6 fuel by combination of KF-1 with phenosansesters of 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid and pentaerythritol, diethylene glycol, ethylene glycol, and thiodiethylene glycol is investigated.

  3. Fire deaths in aircraft without the crashworthy fuel system.

    PubMed

    Springate, C S; McMeekin, R R; Ruehle, C J

    1989-10-01

    Cases reported to the Armed Forces Institute of Pathology were examined for occupants of helicopters without the crashworthy fuel system (CWFS) who survived crashes but died as a result of postcrash fires. There were 16 fire deaths in the 9 such accidents which occurred between January 1976 and April 1984. All of these victims would have survived if there had been no postcrash fire. Partial body destruction by fire probably prevented inclusion of many other cases. The dramatic reduction in fire deaths and injuries due to installation of the CWFS in Army helicopters is discussed. The author concludes that fire deaths and injuries in aircraft accidents could almost be eliminated by fitting current and future aircraft with the CWFS.

  4. An evaluation of the relative fire hazards of jet A and jet B for commercial flight

    NASA Technical Reports Server (NTRS)

    Hibbard, R. R.; Hacker, P. T.

    1973-01-01

    The relative fire hazards of Jet A and Jet B aircraft fuels are evaluated. The evaluation is based on a consideration of the presence of and/or the generation of flammable mixtures in fuel systems, the ignition characteristics, and the flame propagation rates for the two fuel types. Three distinct aircraft operating regimes where fuel type may be a factor in fire hazards are considered. These are: (1) ground handling and refueling, (2) flight, and (3) crash. The evaluation indicates that the overall fire hazards for Jet A are less than for Jet B fuel.

  5. The influence of air duct geometry on air jet direction in aircraft cabin ventilated by mixing ventilation.

    NASA Astrophysics Data System (ADS)

    Fišer, J.; Jícha, M.

    2013-04-01

    The paper deals with instigation of influence of air duct geometry on air jet direction in aircraft cabin ventilated by mixing ventilation. CFD approach was used for investigation and model geometry was based on small aircraft cabin mock-up geometry. Model was also equipped by nine seats and five manikins that represent passengers. The air jet direction was observed for selected ambient environment parameters and several types of air duct geometry and influence of main air duct geometry on jets direction is discussed. The model was created in StarCCM+ ver. 6.04.014 software and polyhedral mesh was used.

  6. 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.

  7. 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.

  8. 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.

    1981-01-01

    A series of Model TFE731-2 engine tests were conducted with the Concept 2 variable geometry airblast fuel injector combustion system installed. The engine was tested to: (1) establish the emission levels over the selected points which comprise the Environmental Protection Agency Landing-Takeoff Cycle; (2) determine engine performance with the combustion system; and (3) evaulate the engine acceleration/deceleration characteristics. The hydrocarbon (HC), carbon monoxide (CO), and smoke goals were met. Oxides of nitrogen (NOx) were above the goal for the same configuration that met the other pollutant goals. The engine and combustor performance, as well as acceleration/deceleration characteristics, were acceptable. The Concept 3 staged combustor system was refined from earlier phase development and subjected to further rig refinement testing. The concept met all of the emissions goals.

  9. Perceived Noise Analysis for Offset Jets Applied to Commercial Supersonic Aircraft

    NASA Technical Reports Server (NTRS)

    Huff, Dennis L.; Henderson, Brenda S.; Berton, Jeffrey J.; Seidel, Jonathan A.

    2016-01-01

    A systems analysis was performed with experimental jet noise data, engine/aircraft performance codes and aircraft noise prediction codes to assess takeoff noise levels and mission range for conceptual supersonic commercial aircraft. A parametric study was done to identify viable engine cycles that meet NASAs N+2 goals for noise and performance. Model scale data from offset jets was used as input to the aircraft noise prediction code to determine the expected sound levels for the lateral certification point where jet noise dominates over all other noise sources. The noise predictions were used to determine the optimal orientation of the offset nozzles to minimize the noise at the lateral microphone location. An alternative takeoff procedure called programmed lapse rate was evaluated for noise reduction benefits. Results show there are two types of engines that provide acceptable range performance; one is a standard mixed-flow turbofan with a single-stage fan, and the other is a three-stream variable-cycle engine with a multi-stage fan. The engine with a single-stage fan has a lower specific thrust and is 8 to 10 EPNdB quieter for takeoff. Offset nozzles reduce the noise directed toward the thicker side of the outer flow stream, but have less benefit as the core nozzle pressure ratio is reduced and the bypass-to-core area ratio increases. At the systems level for a three-engine N+2 aircraft with full throttle takeoff, there is a 1.4 EPNdB margin to Chapter 3 noise regulations predicted for the lateral certification point (assuming jet noise dominates). With a 10 reduction in thrust just after takeoff rotation, the margin increases to 5.5 EPNdB. Margins to Chapter 4 and Chapter 14 levels will depend on the cumulative split between the three certification points, but it appears that low specific thrust engines with a 10 reduction in thrust (programmed lapse rate) can come close to meeting Chapter 14 noise levels. Further noise reduction is possible with additional

  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. Acoustic excitation of liquid fuel droplets and coaxial jets

    NASA Astrophysics Data System (ADS)

    Rodriguez, Juan Ignacio

    This experimental study focuses on two important problems relevant to acoustic coupling with condensed phase transport processes, with special relevance to liquid rocket engine and airbreathing engine combustion instabilities. The first part of this dissertation describes droplet combustion characteristics of various fuels during exposure to external acoustical perturbations. Methanol, ethanol, a liquid synthetic fuel derived from coal gasification via the Fischer-Tropsch process, and a blend of aviation fuel and the synthetic fuel are used. During acoustic excitation, the droplet is situated at or near a pressure node condition, where the droplet experiences the largest velocity perturbations, and at or near a pressure antinode condition, where the droplet is exposed to minimal velocity fluctuations. For unforced conditions, the values of the droplet burning rate constant K of the different fuels are consistent with data in the literature. The location of the droplet with respect to a pressure node or antinode also has a measurable effect on droplet burning rates, which are different for different fuels and in some cases are as high as 28% above the unforced burning rate value. Estimates of flame extinction due to acoustic forcing for different fuels are also obtained. The second part of this work consists of an experimental study on coaxial jet behavior under non-reactive, cryogenic conditions, with direct applications to flow mixing and unstable behavior characterization in liquid rocket engines. These experiments, conducted with nitrogen, span a range of outer to inner jet momentum flux ratios from 0.013 to 23, and explore subcritical, nearcritical and supercritical pressure conditions, with and without acoustic excitation, for two injector geometries. Acoustic forcing at 3 kHz is utilized to maximize the pressure fluctuations within the chamber acting on the jet, reaching maximum values of 4% of the mean chamber pressure. The effect of the magnitude and phase

  12. Long-term exposure to jet fuel: an investigation on occupationally exposed workers with special reference to the nervous system.

    PubMed

    Knave, B; Persson, H E; Goldberg, J M; Westerholm, P

    1976-09-01

    In the present study the results of a neurological and neurophysiological health examination of 29 aircraft factory workers chronically exposed to jet fuel vapors are presented. The exposed subjects were classified into a heavily exposed and a less heavily exposed group. The examination included a standardized clinical neurological examination, measurements of the conduction velocities in the peripheral nerves, and threshold determinations of vibratory sensations in the extremities. All 13 persons examined in the heavily exposed group and 7 of the 16 in the less heavily exposed group stated that they had repeatedly experienced acute effects (dizziness, respiratory tract symptoms, heart palpitations, a feeling of pressure on the chest, nausea, headache) of the jet fuel vapors in the inhaled air. A high rate of symptoms indicative of neurasthenia and psychasthenia and symptoms and signs indicative of polyneuropathy was observed both in the heavily exposed group and in the two groups combined in comparison with reference groups. Considering the presented facts concerning (a) the acute effects on repeated occasions, (b) the high rates of symptoms indicative of neurasthenia and psychasthenia and symptoms and signs indicative of polyneuropathy, and (c) the differences in the observations made between the two groups with varying degrees of exposure to jet fuel, the authors interpreted the results as indicative of a possible effect of long-term exposure to jet fuel on the nervous system.

  13. Personal exposure to JP-8 jet fuel vapors and exhaust at air force bases.

    PubMed Central

    Pleil, J D; Smith, L B; Zelnick, S D

    2000-01-01

    JP-8 jet fuel (similar to commercial/international jet A-1 fuel) is the standard military fuel for all types of vehicles, including the U.S. Air Force aircraft inventory. As such, JP-8 presents the most common chemical exposure in the Air Force, particularly for flight and ground crew personnel during preflight operations and for maintenance personnel performing routine tasks. Personal exposure at an Air Force base occurs through occupational exposure for personnel involved with fuel and aircraft handling and/or through incidental exposure, primarily through inhalation of ambient fuel vapors. Because JP-8 is less volatile than its predecessor fuel (JP-4), contact with liquid fuel on skin and clothing may result in prolonged exposure. The slowly evaporating JP-8 fuel tends to linger on exposed personnel during their interaction with their previously unexposed colleagues. To begin to assess the relative exposures, we made ambient air measurements and used recently developed methods for collecting exhaled breath in special containers. We then analyzed for certain volatile marker compounds for JP-8, as well as for some aromatic hydrocarbons (especially benzene) that are related to long-term health risks. Ambient samples were collected by using compact, battery-operated, personal whole-air samplers that have recently been developed as commercial products; breath samples were collected using our single-breath canister method that uses 1-L canisters fitted with valves and small disposable breathing tubes. We collected breath samples from various groups of Air Force personnel and found a demonstrable JP-8 exposure for all subjects, ranging from slight elevations as compared to a control cohort to > 100 [mutilpe] the control values. This work suggests that further studies should be performed on specific issues to obtain pertinent exposure data. The data can be applied to assessments of health outcomes and to recommendations for changes in the use of personal protective

  14. In situ venting of jet fuel-contaminated soil

    SciTech Connect

    Elliott, M.G.; DePaoli, D.W.

    1989-01-01

    The Air Force Engineering and Services center is performing a field demonstration of in situ soil venting at a 27,000-gallon jet fuel spill site at Hill AFB UT. In situ soil venting is a soil cleanup technique which uses vacuum blowers to pull large volumes of air through contaminated soil. The air flow sweeps out the soil gas, disrupting the equilibrium existing between the contaminants on the soil and in the vapor. This causes volatilization of the contaminants and subsequent removal in the air stream. In situ soil venting has been used for removing volatile contaminants such as gasoline and trichloroethylene, but a full-scale demonstration for removing jet fuel from soil has not been reported. This paper describes our initial site characterization, the one-vent pilot test, and the design and preliminary results of our full-scale in situ soil venting system. 5 refs., 7 figs.

  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. 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.

  17. Application of variable structure system theory to aircraft flight control. [AV-8A and the Augmentor Wing Jet STOL Research Aircraft

    NASA Technical Reports Server (NTRS)

    Calise, A. J.; Kadushin, I.; Kramer, F.

    1981-01-01

    The current status of research on the application of variable structure system (VSS) theory to design aircraft flight control systems is summarized. Two aircraft types are currently being investigated: the Augmentor Wing Jet STOL Research Aircraft (AWJSRA), and AV-8A Harrier. The AWJSRA design considers automatic control of longitudinal dynamics during the landing phase. The main task for the AWJSRA is to design an automatic landing system that captures and tracks a localizer beam. The control task for the AV-8A is to track velocity commands in a hovering flight configuration. Much effort was devoted to developing computer programs that are needed to carry out VSS design in a multivariable frame work, and in becoming familiar with the dynamics and control problems associated with the aircraft types under investigation. Numerous VSS design schemes were explored, particularly for the AWJSRA. The approaches that appear best suited for these aircraft types are presented. Examples are given of the numerical results currently being generated.

  18. Advanced thermally stable jet fuels. Technical progress report, 1995

    SciTech Connect

    Schobert, H.H.; Eser, S.; Song, C.

    1996-04-01

    The Penn State program in advanced thermally stable jet fuels has five components:(1) development of mechanisms of degradation and solids formation; (2) quantitative measurement of growth of sub- micrometer and micrometer sized particles suspended in fuels during thermal stressing; (3) characterization of carbonaceous deposits by various instrumental and microscopic methods; (4) elucidation of the role of additives in retarding the formation of carbonaceous solids; and (5) assessment of the potential of producing high yields of cycloalkanes and hydroaromatics by direct liquefaction of coal. Progress reports for these tasks are presented.

  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. Mixing enhancement in a scramjet combustor using fuel jet injection swirl

    NASA Astrophysics Data System (ADS)

    Flesberg, Sonja M.

    The scramjet engine has proven to be a viable means of powering a hypersonic vehicle, especially after successful flights of the X-51 WaveRider and various Hy-SHOT test vehicles. The major challenge associated with operating a scramjet engine is the short residence time of the fuel and oxidizer in the combustor. The fuel and oxidizer have only milliseconds to mix, ignite and combust in the combustion chamber. Combustion cannot occur until the fuel and oxidizer are mixed on a molecular level. Therefore the improvement of mixing is of utmost interest since this can increase combustion efficiency. This study investigated mixing enhancement of fuel and oxidizer within the combustion chamber of a scramjet by introducing swirl to the fuel jet. The investigation was accomplished with numerical simulations using STAR-CCM+ computational fluid dynamic software. The geometry of the University of Virginia Supersonic Combustion Facility was used to model the isolator, combustor and nozzle of a scramjet engine for simulation purposes. Experimental data from previous research at the facility was used to verify the simulation model before investigating the effect of fuel jet swirl on mixing. The model used coaxial fuel jet with a swirling annular jet. Single coaxial fuel jet and dual coaxial fuel jet configurations were simulated for the investigation. The coaxial fuel jets were modelled with a swirling annular jet and non-swirling core jet. Numerical analysis showed that fuel jet swirl not only increased mixing and entrainment of the fuel with the oxidizer but the mixing occurred further upstream than without fuel jet swirl. The burning efficiency was calculated for the all the configurations. An increase in burning efficiency indicated an increase in the mixing of H2 with O2. In the case of the single fuel jet models, the maximum burning efficiency increase due to fuel injection jet swirl was 23.3%. The research also investigated the possibility that interaction between two

  2. Sound Pressures and Correlations of Noise on the Fuselage of a Jet Aircraft in Flight

    NASA Technical Reports Server (NTRS)

    Shattuck, Russell D.

    1961-01-01

    Tests were conducted at altitudes of 10,000, 20,000, and 30,000 feet at speeds of Mach 0.4, 0.6, and O.8. It was found that the sound pressure levels on the aft fuselage of a jet aircraft in flight can be estimated using an equation involving the true airspeed and the free air density. The cross-correlation coefficient over a spacing of 2.5 feet was generalized with Strouhal number. The spectrum of the noise in flight is comparatively flat up to 10,000 cycles per second.

  3. Shuttle spacelab simulation using a Lear jet aircraft: Mission no. 3 (ASSESS program)

    NASA Technical Reports Server (NTRS)

    Reller, J. O., Jr.; Neel, C. B.; Mason, R. H.

    1974-01-01

    The third ASSESS mission using a Lear Jet aircraft conducted to continue the study of scientific experiment operations in a simulated Spacelab environment. Prior to the mission, research planning and equipment preparation were observed and documented. A flight readiness review for the experiment was conducted. Nine of the ten scheduled flights were completed during simulation mission and all major science objectives were accomplished. The equipment was well qualified for flight and gave little trouble; telescope malfunctions occurred early in the mission and were corrected. Both real-time and post-observation data evaluation were used to assess research progress and to plan subsequent flight observations for maximum effectiveness.

  4. A Survey of Jet Aircraft PM by TEM in APEX III

    NASA Technical Reports Server (NTRS)

    VanderWal, Randy L.; Bryg, Victoria M.

    2014-01-01

    Based upon field testing during the NASA led APEX III campaign conducted in November 2005 at the NASA Glenn Research Center in coordination with Continental Airlines and Cleveland Hopkins International Airport. This paper reports observations of particulate emissions collected from a suite of jet engine aircraft to assess differences and similarities in soot macro- micro- and nanostructure using transmission electron microscopy (TEM). Aggregates are compact, primary particle sizes varied and nanostructure mixed. Comparisons are made to more familiar laboratory flame-generated soot as a well-studied point of reference. Results are interpreted in terms of turbulence interacting with the different stages of particle formation and growth.

  5. Stability of sequences generated by nonlinear differential systems. [for analysis of glider jet aircraft motion

    NASA Technical Reports Server (NTRS)

    Brown, R. L.

    1979-01-01

    A local stability analysis is presented for both the analytic and numerical solutions of the initial value problem for a system of ordinary differential equations. It is shown that, using a proper choice of Liapunov function, a connected region of stable initial values of both the analytic solution and the one-leg k-step numerical solution can be approximated. Attention is given to the example of the two-dimensional problem involving the stability of the longitudinal equations of motion of a gliding jet aircraft.

  6. A survey of jet aircraft PM by TEM in APEX III

    NASA Astrophysics Data System (ADS)

    Huang, Chung-Hsuan; Bryg, Victoria M.; Vander Wal, Randy L.

    2016-09-01

    Results are reported for sampling non-volatile particulate matter from field tests during the NASA led APEX III campaign. This paper reports observations of particulate emissions collected from a suite of jet engine aircraft to assess differences and similarities in soot macro- micro- and nanostructure using TEM. Aggregates are compact, primary particle sizes varied and nanostructure is mixed. Comparisons are made to soot from a laboratory flame as a well-studied reference. Results are interpreted in terms of turbulence interacting with the different stages of particle formation and growth with implications for atmospheric processing and climate impact.

  7. 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.

  8. Performance Evaluation of Particle Sampling Probes for Emission Measurements of Aircraft Jet Engines

    NASA Technical Reports Server (NTRS)

    Lee, Poshin; Chen, Da-Ren; Sanders, Terry (Technical Monitor)

    2001-01-01

    Considerable attention has been recently received on the impact of aircraft-produced aerosols upon the global climate. Sampling particles directly from jet engines has been performed by different research groups in the U.S. and Europe. However, a large variation has been observed among published data on the conversion efficiency and emission indexes of jet engines. The variation results surely from the differences in test engine types, engine operation conditions, and environmental conditions. The other factor that could result in the observed variation is the performance of sampling probes used. Unfortunately, it is often neglected in the jet engine community. Particle losses during the sampling, transport, and dilution processes are often not discussed/considered in literatures. To address this issue, we evaluated the performance of one sampling probe by challenging it with monodisperse particles. A significant performance difference was observed on the sampling probe evaluated under different temperature conditions. Thermophoretic effect, nonisokinetic sampling and turbulence loss contribute to the loss of particles in sampling probes. The results of this study show that particle loss can be dramatic if the sampling probe is not well designed. Further, the result allows ones to recover the actual size distributions emitted from jet engines.

  9. 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.

  10. Liquid Fuel Emulsion Jet-in-Crossflow Penetration and Dispersion Under High Pressure Conditions

    NASA Astrophysics Data System (ADS)

    Gomez, Guillermo Andres

    The current work focuses on the jet-in-crossflow penetration and dispersion behavior of water-in-oil emulsions in a high pressure environment. Both fuel injection strategies of using a water-in-oil emulsion and a jet-in-crossflow have demonstrated unique benefits in improving gas turbine performance from an emissions and efficiency standpoint. A jet-in-crossflow is very practical for use in gas turbine engines, rocket propulsion, and aircraft engines since it utilizes already available crossflow air to atomize fuel. Injecting water into a combustion chamber in the form of a water-in-oil emulsion allows for pollutant emissions reduction while reducing efficiency loses that may result from using a separate water or steam injection circuit. Dispersion effects on oil droplets are expected, therefore investigating the distribution of both oil and water droplets in the crossflow is an objective in this work. Understanding the synchronization and injection behavior of the two strategies is of key interest due to their combined benefits. A water-to-oil ratio and an ambient pressure parameter are developed for emulsion jet-in-crossflow trajectories. To this end, a total of 24 emulsion jet-in-crossflow tests were performed with varying ambient pressures of 2-8 atm and momentum flux ratios of 50, 85, and 120. Sobel edge filtering was applied to each averaged image obtained from a high speed video of each test case. Averaged and filtered images were used to resolve top and bottom edges of the trajectory in addition to the overall peak intensity up to 40 mm downstream of the injection point. An optimized correlation was established and found to differ from literature based correlations obtained under atmospheric pressure conditions. Overall it was found that additional parameters were not necessary for the top edge and peak intensity correlations, but a need for a unique emulsion bottom edge and width trajectory correlation was recognized. In addition to investigating emulsion

  11. 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.

  12. Jet flames of a refuse derived fuel

    SciTech Connect

    Weber, Roman; Kupka, Tomasz; Zajac, Krzysztof

    2009-04-15

    This paper is concerned with combustion of a refuse derived fuel in a small-scale flame. The objective is to provide a direct comparison of the RDF flame properties with properties of pulverized coal flames fired under similar boundary conditions. Measurements of temperature, gas composition (O{sub 2}, CO{sub 2}, CO, NO) and burnout have demonstrated fundamental differences between the coal flames and the RDF flames. The pulverized coals ignite in the close vicinity of the burner and most of the combustion is completed within the first 300 ms. Despite the high volatile content of the RDF, its combustion extends far into the furnace and after 1.8 s residence time only a 94% burnout has been achieved. This effect has been attributed not only to the larger particle size of fluffy RDF particles but also to differences in RDF volatiles if compared to coal volatiles. Substantial amounts of oily tars have been observed in the RDF flames even though the flame temperatures exceeded 1300 C. The presence of these tars has enhanced the slagging propensity of RDF flames and rapidly growing deposits of high carbon content have been observed. (author)

  13. 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.

  14. 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.

  15. 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.

  16. Feedback laws for fuel minimization for transport aircraft

    NASA Technical Reports Server (NTRS)

    Price, D. B.; Gracey, C.

    1984-01-01

    The Theoretical Mechanics Branch has as one of its long-range goals to work toward solving real-time trajectory optimization problems on board an aircraft. This is a generic problem that has application to all aspects of aviation from general aviation through commercial to military. Overall interest is in the generic problem, but specific problems to achieve concrete results are examined. The problem is to develop control laws that generate approximately optimal trajectories with respect to some criteria such as minimum time, minimum fuel, or some combination of the two. These laws must be simple enough to be implemented on a computer that is flown on board an aircraft, which implies a major simplification from the two point boundary value problem generated by a standard trajectory optimization problem. In addition, the control laws allow for changes in end conditions during the flight, and changes in weather along a planned flight path. Therefore, a feedback control law that generates commands based on the current state rather than a precomputed open-loop control law is desired. This requirement, along with the need for order reduction, argues for the application of singular perturbation techniques.

  17. Effects of simulated jet aircraft noise on heart rate and behavior of desert ungulates

    SciTech Connect

    Weisenberger, M.E.; Krausman, P.R.; Wallace, M.C.

    1996-01-01

    Many landscapes underlying military designated air spaces have been established as national parks, wildlife refuges, or wilderness areas. The juxtaposition of public, wilderness, and military uses has led to questions of compatibility between aircraft and wildlife. We evaluated the effects of simulated low-altitude jet aircraft noise on the behavior and heart rate of captive desert mule deer (n = 6) and mountain sheep (n - 5). We measured heart rate and behavior related to the number of simulated overflights (n = 112 overflights/season) during 3 seasons. The heart rates of ungulates increased related to dB levels during simulated overflights (P {le} 0.05), but they returned to pre-disturbance levels in 60-180 seconds. Animal behavior also changed during overflights but returned to pre-disturbance condition in {le}252 seconds (P {le} 0.005). All animal responses decreased with increased exposure suggesting that they habituated to simulated sound levels of low-altitude aircraft. 43 refs., 5 tabs.

  18. Jet Noise Modeling for Suppressed and Unsuppressed Aircraft in Simulated Flight

    NASA Technical Reports Server (NTRS)

    Stone, James R.; Krejsa, Eugene A.; Clark, Bruce J; Berton, Jeffrey J.

    2009-01-01

    This document describes the development of further extensions and improvements to the jet noise model developed by Modern Technologies Corporation (MTC) for the National Aeronautics and Space Administration (NASA). The noise component extraction and correlation approach, first used successfully by MTC in developing a noise prediction model for two-dimensional mixer ejector (2DME) nozzles under the High Speed Research (HSR) Program, has been applied to dual-stream nozzles, then extended and improved in earlier tasks under this contract. Under Task 6, the coannular jet noise model was formulated and calibrated with limited scale model data, mainly at high bypass ratio, including a limited-range prediction of the effects of mixing-enhancement nozzle-exit chevrons on jet noise. Under Task 9 this model was extended to a wider range of conditions, particularly those appropriate for a Supersonic Business Jet, with an improvement in simulated flight effects modeling and generalization of the suppressor model. In the present task further comparisons are made over a still wider range of conditions from more test facilities. The model is also further generalized to cover single-stream nozzles of otherwise similar configuration. So the evolution of this prediction/analysis/correlation approach has been in a sense backward, from the complex to the simple; but from this approach a very robust capability is emerging. Also from these studies, some observations emerge relative to theoretical considerations. The purpose of this task is to develop an analytical, semi-empirical jet noise prediction method applicable to takeoff, sideline and approach noise of subsonic and supersonic cruise aircraft over a wide size range. The product of this task is an even more consistent and robust model for the Footprint/Radius (FOOTPR) code than even the Task 9 model. The model is validated for a wider range of cases and statistically quantified for the various reference facilities. The possible

  19. Platelet activating factor receptor binding plays a critical role in jet fuel-induced immune suppression.

    PubMed

    Ramos, Gerardo; Kazimi, Nasser; Nghiem, Dat X; Walterscheid, Jeffrey P; Ullrich, Stephen E

    2004-03-15

    Applying military jet fuel (JP-8) or commercial jet fuel (Jet-A) to the skin of mice suppresses the immune response in a dose-dependent manner. The release of biological response modifiers, particularly prostaglandin E2 (PGE2), is a critical step in activating immune suppression. Previous studies have shown that injecting selective cyclooxygenase-2 inhibitors into jet fuel-treated mice blocks immune suppression. Because the inflammatory phospholipid mediator, platelet-activating factor (PAF), up-regulates cyclooxygenase-2 production and PGE2 synthesis by keratinocytes, we tested the hypothesis that PAF-receptor binding plays a role in jet fuel-induced immune suppression. Treating keratinocyte cultures with PAF and/or jet fuel (JP-8 and Jet-A) stimulates PGE2 secretion. Jet fuel-induced PGE2 production was suppressed by treating the keratinocytes with specific PAF-receptor antagonists. Injecting mice with PAF, or treating the skin of the mice with JP-8, or Jet-A, induced immune suppression. Jet fuel-induced immune suppression was blocked when the jet fuel-treated mice were injected with PAF-receptor antagonists before treatment. Jet fuel treatment has been reported to activate oxidative stress and treating the mice with anti-oxidants (Vitamins C, or E or beta-hydroxy toluene), before jet fuel application, interfered with immune suppression. These findings confirm previous studies showing that PAF-receptor binding can modulate immune function. Furthermore, they suggest that PAF-receptor binding may be an early event in the induction of immune suppression by immunotoxic environmental agents that target the skin. PMID:15020195

  20. 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.

  1. Computer analysis of effects of altering jet fuel properties on refinery costs and yields

    NASA Technical Reports Server (NTRS)

    Breton, T.; Dunbar, D.

    1984-01-01

    This study was undertaken to evaluate the adequacy of future U.S. jet fuel supplies, the potential for large increases in the cost of jet fuel, and to what extent a relaxation in jet fuel properties would remedy these potential problems. The results of the study indicate that refiners should be able to meet jet fuel output requirements in all regions of the country within the current Jet A specifications during the 1990-2010 period. The results also indicate that it will be more difficult to meet Jet A specifications on the West Coast, because the feedstock quality is worse and the required jet fuel yield (jet fuel/crude refined) is higher than in the East. The results show that jet fuel production costs could be reduced by relaxing fuel properties. Potential cost savings in the East (PADDs I-IV) through property relaxation were found to be about 1.3 cents/liter (5 cents/gallon) in January 1, 1981 dollars between 1990 and 2010. However, the savings from property relaxation were all obtained within the range of current Jet A specifications, so there is no financial incentive to relax Jet A fuel specifications in the East. In the West (PADD V) the potential cost savings from lowering fuel quality were considerably greater than in the East. Cost savings from 2.7 to 3.7 cents/liter (10-14 cents/gallon) were found. In contrast to the East, on the West Coast a significant part of the savings was obtained through relaxation of the current Jet A fuel specifications.

  2. Coal liquefaction process wherein jet fuel, diesel fuel and/or ASTM No. 2 fuel oil is recovered

    DOEpatents

    Bauman, Richard F.; Ryan, Daniel F.

    1982-01-01

    An improved process for the liquefaction of coal and similar solid carbonaceous materials wherein a hydrogen donor solvent or diluent derived from the solid carbonaceous material is used to form a slurry of the solid carbonaceous material and wherein the naphthenic components from the solvent or diluent fraction are separated and used as jet fuel components. The extraction increases the relative concentration of hydroaromatic (hydrogen donor) components and as a result reduces the gas yield during liquefaction and decreases hydrogen consumption during said liquefaction. The hydrogenation severity can be controlled to increase the yield of naphthenic components and hence the yield of jet fuel and in a preferred embodiment jet fuel yield is maximized while at the same time maintaining solvent balance.

  3. Coal liquefaction process wherein jet fuel, diesel fuel and/or astm no. 2 fuel oil is recovered

    SciTech Connect

    Bauman, R.F.; Ryan, D.F.

    1982-06-01

    An improved process for the liquefaction of coal and similar solid carbonaceous materials wherein a hydrogen donor solvent or diluent derived from the solid carbonaceous material is used to form a slurry of the solid carbonaceous material and wherein the naphthenic components from the solvent or diluent fraction are separated and used as jet fuel components. The extraction increases the relative concentration of hydroaromatic (hydrogen donor) components and as a result reduces the gas yield during liquefaction and decreases hydrogen consumption during said liquefaction. The hydrogenation severity can be controlled to increase the yield of naphthenic components and hence the yield of jet fuel and in a preferred embodiment jet fuel yield is maximized while at the same time maintaining solvent balance.

  4. Neuropsychiatric symptoms in workers occupationally exposed to jet fuel--a combined epidemiological and casuistic study.

    PubMed

    Struwe, G; Knave, B; Mindus, P

    1983-01-01

    Some aircraft personel and airline industry workers are exposed to jet fuel, a mixture of aliphatic hydrocarbons (petroleum 80%) and some organic solvents (petroleum 80%) and some organic solvents (aromatic hydrocarbons 20%). In order to evaluate the possible neuropsychiatric sequeale of such long-term occupational exposure, we examined 30 workers exposed at about 250 mg/m3 for 4-32 years at a jet motor factory. They were compared with two control groups (2 x 30) of matched non-exposed workers. The medical history was first assessed by standardized interviews and examination of medical records kept by the factory physician. The exposed subjects had, after their employment, much more often sought medical advice because of emotional dysfunctions, such as depression and anxiety, than had the control groups (P less than 0.005). When the prevalent mental symptoms, indicative of brain lesion, later were rated by psychiatrists, the exposed workers scored higher than did the controls (P less than 0.001). 14 subjects showing most symptoms were then selected for a thorough neuropsychiatric clinical investigation comprising psychosocial inquiries, psychological testing, personality assessment and neurological/neurophysiological examination. Seven were judged to suffer from mild organic brain syndrome (i.e. "organic neurasthenia") of which one subject was a severe case. The subjects had all undergone a slow but steady personality change over the years--starting from an ordinary strength without neurotic traits and moving towards an asthenic state with fatigue, anxiety and vegetative hyperreactivity. No other cause for this change could be identified as an alternative to the occupational exposure to jet fuel. It is concluded that personality changes and emotional dysfunctions are the foremost effects of such long-term exposure to petroleum products. PMID:6575584

  5. Emergency Flight Control of a Twin-Jet Commercial Aircraft using Manual Throttle Manipulation

    NASA Technical Reports Server (NTRS)

    Cole, Jennifer H.; Cogan, Bruce R.; Fullerton, C. Gordon; Burken, John J.; Venti, Michael W.; Burcham, Frank W.

    2007-01-01

    The Department of Homeland Security (DHS) created the PCAR (Propulsion-Controlled Aircraft Recovery) project in 2005 to mitigate the ManPADS (man-portable air defense systems) threat to the commercial aircraft fleet with near-term, low-cost proven technology. Such an attack could potentially cause a major FCS (flight control system) malfunction or other critical system failure onboard the aircraft, despite the extreme reliability of current systems. For the situations in which nominal flight controls are lost or degraded, engine thrust may be the only remaining means for emergency flight control [ref 1]. A computer-controlled thrust system, known as propulsion-controlled aircraft (PCA), was developed in the mid 1990s with NASA, McDonnell Douglas and Honeywell. PCA's major accomplishment was a demonstration of an automatic landing capability using only engine thrust [ref 11. Despite these promising results, no production aircraft have been equipped with a PCA system, due primarily to the modifications required for implementation. A minimally invasive option is TOC (throttles-only control), which uses the same control principles as PCA, but requires absolutely no hardware, software or other aircraft modifications. TOC is pure piloting technique, and has historically been utilized several times by flight crews, both military and civilian, in emergency situations stemming from a loss of conventional control. Since the 1990s, engineers at NASA Dryden Flight Research Center (DFRC) have studied TOC, in both simulation and flight, for emergency flight control with test pilots in numerous configurations. In general, it was shown that TOC was effective on certain aircraft for making a survivable landing. DHS sponsored both NASA Dryden Flight Research Center (Edwards, CA) and United Airlines (Denver, Colorado) to conduct a flight and simulation study of the TOC characteristics of a twin-jet commercial transport, and assess the ability of a crew to control an aircraft down to

  6. Experimental and Numerical Studies for Soot Formation in Laminar Coflow Diffusion Flames of Jet A-1 and Synthetic Jet Fuels

    NASA Astrophysics Data System (ADS)

    Saffaripour, Meghdad

    In the present doctoral thesis, fundamental experimental and numerical studies are conducted for the laminar, atmospheric pressure, sooting, coflow diffusion flames of Jet A-1 and synthetic jet fuels. The first part of this thesis presents a comparative experimental study for Jet A-1, which is a widely used petroleum-based fuel, and four synthetically produced alternative jet fuels. The main goals of this part of the thesis are to compare the soot emission levels of the alternative fuels to those of a standard fuel, Jet A-1, and to determine the effect of fuel chemical composition on soot formation characteristics. To achieve these goals, experimental measurements are constructed and performed for flame temperature, soot concentration, soot particle size, and soot aggregate structure in the flames of pre-vaporized jet fuels. The results show that a considerable reduction in soot production, compared to the standard fuel, can be obtained by using synthetic fuels which will help in addressing future regulations. A strong correlation between the aromatic content of the fuels and the soot concentration levels in the flames is observed. The second part of this thesis presents the development and experimental validation of a fully-coupled soot formation model for laminar coflow jet fuel diffusion flames. The model is coupled to a detailed kinetic mechanism to predict the chemical structure of the flames and soot precursor concentrations. This model also provides information on size and morphology of soot particles. The flames of a three-component surrogate for Jet A-1, a three-component surrogate for a synthetic jet fuel, and pure n-decane are simulated using this model. Concentrations of major gaseous species and flame temperatures are well predicted by the model. Soot volume fractions are predicted reasonably well everywhere in the flame, except near the flame centerline where soot concentrations are underpredicted by a factor of up to five. There is an excellent

  7. Thermal Stability Testing of Fischer-Tropsch Fuel and Various Blends with Jet A, as Well as Aromatic Blend Additives

    NASA Technical Reports Server (NTRS)

    Klettlinger, J.; Rich, R.; Yen, C.; Surgenor, A.

    2011-01-01

    Fischer-Tropsch (F-T) jet fuel composition differs from petroleum-based, conventional commercial jet fuel because of differences in feedstock and production methodology. Fischer-Tropsch fuel typically has a lower aromatic and sulfur content and consists primarily of iso and normal parafins. The ASTM D3241 specification for Jet Fuel Thermal Oxidation Test (JFTOT) break point testing method was used to test the breakpoint of a baseline conventional Jet A, a commercial grade F-T jet fuel, and various blends of this F-T fuel in Jet A. The testing completed in this report was supported by the NASA Fundamental Aeronautics Subsonics Fixed Wing Project.

  8. 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.

  9. 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.

  10. Forecast of jet engine exhaust emissions for future high altitude commercial aircraft

    NASA Technical Reports Server (NTRS)

    Grobman, J.; Ingebo, R. D.

    1974-01-01

    Projected minimum levels of engine exhaust emissions that may be practicably achievable for future commercial aircraft operating at high altitude cruise conditions are presented. The forecasts are based on: (1) current knowledge of emission characteristics of combustors and augmentors; (2) the current status of combustion research in emission reduction technology; (3) predictable trends in combustion systems and operating conditions as required for projected engine designs that are candidates for advanced subsonic or supersonic commercial aircraft. Results are presented for cruise conditions in terms of an emission index, g pollutant/kg fuel. Two sets of engine exhaust emission predictions are presented: the first, based on an independent NASA study and the second, based on the consensus of an ad hoc committee composed of industry, university, and government representatives. The consensus forecasts are in general agreement with the NASA forecasts.

  11. On the reverse flow ceiling jet in pool fire-ventilation crossflow interactions in a simulated aircraft cabin interior

    NASA Technical Reports Server (NTRS)

    Kwack, E. Y.; Bankston, C. P.; Shakkottai, P.; Back, L. H.

    1989-01-01

    The behavior of the reverse flow ceiling jet against the ventilation flow from 0.58 to 0.87 m/s was investigated in a 1/3 scale model of a wide body aircraft interior. For all tests, strong reverse-flow ceiling jets of hot gases were detected well upstream of the fire. Both thicknesses of the reverse-flow ceiling jet and the smoke layer increased with the fire-crossflow parameter. The thickness of the smoke layer where the smoke flows along the main flow below the reverse-flow ceiling jet was almost twice that of the reverse-flow ceiling jet. Detailed spatial and time-varying temperatures of the gas in the test section were measured, and velocity profiles were also measured using a temperature compensated hot film.

  12. The effects of jet fuel on immune cells of fuel system maintenance workers.

    PubMed

    Rhodes, A Gayle; LeMasters, Grace Kawas; Lockey, James E; Smith, James W; Yiin, James H; Egeghy, Peter; Gibson, Roger

    2003-01-01

    Jet fuel is a common occupational exposure among commercial and military maintenance workers. JP-8 jet fuel, a military formulation, has shown immunotoxic effects in mice, but little data exist for humans. The aim of this cross-sectional study was to determine whether immune cell counts in the peripheral blood were altered among tank entry workers at three Air Force bases. After adjusting for covariates, fuel system maintenance personnel (n = 45) were found to have significantly higher counts of white blood cells (P = 0.01), neutrophils (P = 0.05), and monocytes (P = 0.02) when compared with a low-exposure group (n = 78), but no differences were noted in the numbers of total lymphocytes, T-cells, T-helper cells, T-suppressor cells, natural killer cells, and B-cells. Investigations are needed to evaluate the functional ability of these cells to produce lymphokines and cytokines and modulate the immune system.

  13. 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.

  14. 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.

  15. Classification of jet fuel properties by near-infrared spectroscopy using fuzzy rule-building expert systems and support vector machines.

    PubMed

    Xu, Zhanfeng; Bunker, Christopher E; Harrington, Peter de B

    2010-11-01

    Monitoring the changes of jet fuel physical properties is important because fuel used in high-performance aircraft must meet rigorous specifications. Near-infrared (NIR) spectroscopy is a fast method to characterize fuels. Because of the complexity of NIR spectral data, chemometric techniques are used to extract relevant information from spectral data to accurately classify physical properties of complex fuel samples. In this work, discrimination of fuel types and classification of flash point, freezing point, boiling point (10%, v/v), boiling point (50%, v/v), and boiling point (90%, v/v) of jet fuels (JP-5, JP-8, Jet A, and Jet A1) were investigated. Each physical property was divided into three classes, low, medium, and high ranges, using two evaluations with different class boundary definitions. The class boundaries function as the threshold to alarm when the fuel properties change. Optimal partial least squares discriminant analysis (oPLS-DA), fuzzy rule-building expert system (FuRES), and support vector machines (SVM) were used to build the calibration models between the NIR spectra and classes of physical property of jet fuels. OPLS-DA, FuRES, and SVM were compared with respect to prediction accuracy. The validation of the calibration model was conducted by applying bootstrap Latin partition (BLP), which gives a measure of precision. Prediction accuracy of 97 ± 2% of the flash point, 94 ± 2% of freezing point, 99 ± 1% of the boiling point (10%, v/v), 98 ± 2% of the boiling point (50%, v/v), and 96 ± 1% of the boiling point (90%, v/v) were obtained by FuRES in one boundaries definition. Both FuRES and SVM obtained statistically better prediction accuracy over those obtained by oPLS-DA. The results indicate that combined with chemometric classifiers NIR spectroscopy could be a fast method to monitor the changes of jet fuel physical properties.

  16. Aircraft fuel conservation. (Latest citations from the NTIS bibliographic database). Published Search

    SciTech Connect

    1995-12-01

    The bibliography contains citations concerning means to conserve fuel in airline operations. Included are abstracts dealing with aircraft design, engine design, propulsion efficiency, fuels, and operating procedures which conserve fuel.(Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  17. Aircraft fuel conservation. (Latest citations from the NTIS bibliographic database). Published Search

    SciTech Connect

    Not Available

    1994-05-01

    The bibliography contains citations concerning means to conserve fuel in airline operations. Included are abstracts dealing with aircraft design, engine design, propulsion efficiency, fuels, and operating procedures which conserve fuel. (Contains 250 citations and includes a subject term index and title list.)

  18. Aircraft fuel conservation. (Latest citations from the NTIS Bibliographic database). Published Search

    SciTech Connect

    Not Available

    1993-10-01

    The bibliography contains citations concerning means to conserve fuel in airline operations. Included are abstracts dealing with aircraft design, engine design, propulsion efficiency, fuels, and operating procedures which conserve fuel. (Contains 250 citations and includes a subject term index and title list.)

  19. Aircraft fuel conservation. (Latest citations from the NTIS bibliographic database). Published Search

    SciTech Connect

    1997-04-01

    The bibliography contains citations concerning means to conserve fuel in airline operations. Included are abstracts dealing with aircraft design, engine design, propulsion efficiency, fuels, and operating procedures which conserve fuel.(Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  20. Aircraft fuel conservation. (Latest citations from the NTIS bibliographic database). Published Search

    SciTech Connect

    1995-03-01

    The bibliography contains citations concerning means to conserve fuel in airline operations. Included are abstracts dealing with aircraft design, engine design, propulsion efficiency, fuels, and operating procedures which conserve fuel. (Contains 250 citations and includes a subject term index and title list.)

  1. ASSESS program: Shuttle Spacelab simulation using a Lear jet aircraft (mission no. 2)

    NASA Technical Reports Server (NTRS)

    Reller, J. O., Jr.; Neel, C. B.; Mason, R. H.; Pappas, C. C.

    1974-01-01

    The second shuttle Spacelab simulation mission of the ASSESS program was conducted at Ames Research Center by the Airborne Science Office (ASO) using a Lear jet aircraft based at a site remote from normal flight operations. Two experimenters and the copilot were confined to quarters on the site during the mission, departing only to do in-flight research in infrared astronomy. A total of seven flights were made in a period of 4 days. Results show that experimenters with relatively little flight experience can plan and carry out a successful research effort under isolated and physically rigorous conditions, much as would more experienced scientists. Perhaps the margin of success is not as great, but the primary goal of sustained acquisition of significant data over a 5-day period can be achieved.

  2. Jet stream winds - Enhanced aircraft data acquisition and analysis over Southwest Asia

    NASA Technical Reports Server (NTRS)

    Tenenbaum, J.

    1989-01-01

    A project is described for providing the accurate initial and verification analyses for the jet stream in regions where general circulation models are known to have large systematic errors, either due to the extreme sparsity of data or to incorrect physical parameterizations. For this purpose, finely spaced aircraft-based meteorological data for the Southwest Asian regions collected for three 10-day periods in the winter of 1988-1989 will be used, together with corresponding data for the North American regions used as a control, to rerun the assimilation cycles and forecast models of the NMC and the NASA Goddard Laboratory for Atmospheres. Data for Southeast Asia will be collected by three carriers with extensive wide-body routes crossing the total region, while data for the North American region will be obtained from the archives of ACARS and GTS.

  3. MEETING IN VANCOUVER, B.C.: MICRONUCLEUS STUDIES IN THE PERIPHERAL BLOOD AND BONE MARROW OF MICE TREATED WITH JET FUELS, JP-8 AND JET-A

    EPA Science Inventory

    The potential adverse effects of dermal and inhalation exposure of jet fuels are important for health hazard evaluation in humans. In an animal model, the genotoxic potential of jet fuels, JP-8 and Jet-A, was investigated. Mice were treated dermally with either a single or multip...

  4. MICRONUCLEUS STUDIES IN THE PERIPHERAL BLOOD AND BONE MARROW OF MICE TREATED WITH JET FUELS, JP-8 AND JET-A

    EPA Science Inventory

    The potential adverse effects of dermal and inhalation exposure of jet fuels are important for health hazard evaluation in humans. In an animal model, the genotoxic potential of jet fuels, JP-8 and Jet-A, was investigated. Mice were treated dermally with either a single or multip...

  5. 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.

  6. Effects of jet fuel spills on the microbial community of soil

    SciTech Connect

    Song, Hong-Gyu; Bartha, R. )

    1990-03-01

    Hydrocarbon residues, microbial numbers, and microbial activity were measured and correlated in loam soil contaminated by jet fuel spills resulting in 50 and 135 mg of hydrocarbon g of soil{sup {minus}1}. Contaminated soil was incubated at 27{degree}C either as well-aerated surface soil or as poorly aerated subsurface soil. In the former case, the effects of bioremediation treatment on residues, microbial numbers, and microbial activity were also assessed. Hydrocarbon residues were measured by quantitative gas chromatography. Enumerations included direct counts of metabolically active bacteria, measurement of mycelial length, plate counts of aerobic heterotrophs, and most probable numbers of hydrocarbon degraders. Activity was assessed by fluorescein diacetate (FDA) hydrolysis. Jet fuel disappeared much more rapidly from surface soil than it did from subsurface soil. In surface soil, microbial numbers and mycelial length were increased by 2 to 2.5 orders of magnitude as a result of jet fuel contamination alone and by 3 to 4 orders of magnitude as a result of the combination of jet fuel contamination and bioremediation. FDA hydrolysis was stimulated by jet fuel and bioremediation, but was inhibited by jet fuel alone. The latter was traced to an inhibition of the FDA assay by jet fuel biodegradation products. In subsurface soil, oxygen limitation strongly attenuated microbial responses to jet fuel. An increase in the most probable numbers of hydrocarbon degraders was accompanied by a decline in other aerobic heterotrophs, so that total plate counts changed little.

  7. Jet Fuel from Camelina: Jet Fuel From Camelina Sativa: A Systems Approach

    SciTech Connect

    2012-01-01

    PETRO Project: NC State will genetically modify the oil-crop plant Camelina sativa to produce high quantities of both modified oils and terpenes. These components are optimized for thermocatalytic conversion into energy-dense drop-in transportation fuels. The genetically engineered Camelina will capture more carbon than current varieties and have higher oil yields. The Camelina will be more tolerant to drought and heat, which makes it suitable for farming in warmer and drier climate zones in the US. The increased productivity of NC State’s-enhanced Camelina and the development of energy-effective harvesting, extraction, and conversion technology could provide an alternative non-petrochemical source of fuel.

  8. 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.

  9. Chemistry Characterization of Jet Aircraft Engine Particulate by XPS: Results from APEX III

    NASA Technical Reports Server (NTRS)

    Vander Wal, Randy L.; Bryg, Victoria M.

    2014-01-01

    This paper reports XPS analysis of jet exhaust particulate from a B737, Lear, ERJ, and A300 aircraft during the APEX III NASA led field campaign. Carbon hybridization and bonding chemistry are identified by high-resolution scans about the C1s core-shell region. Significant organic content as gauged by the sp3/sp2 ratio is found across engines and platforms. Polar oxygen functional groups include carboxylic, carbonyl and phenol with combined content of 20 percent or more. By lower resolution survey scans various elements including transition metals are identified along with lighter elements such as S, N, and O in the form of oxides. Burning additives within lubricants are probable sources of Na, Ba, Ca, Zn, P and possibly Sn. Elements present and their percentages varied significantly across all engines, not revealing any trend or identifiable cause for the differences, though the origin is likely the same for the same element when observed. This finding suggests that their presence can be used as a tracer for identifying soots from aircraft engines as well as diagnostic for monitoring engine performance and wear.

  10. Spacelab simulation using a Lear Jet aircraft: Mission no. 4 (ASSESS program)

    NASA Technical Reports Server (NTRS)

    Reller, J. O., Jr.; Neel, C. B.; Mason, R. H.

    1975-01-01

    The fourth ASSESS Spacelab simulation mission utilizing a Lear Jet aircraft featured trained experiment operators (EOs) in place of the participating scientists, to simulate the role and functions of payload specialists in Spacelab who may conduct experiments developed by other scientists. The experiment was a broadband infrared photometer coupled to a 30-cm, open port, IR telescope. No compromises in equipment design or target selection were made to simplify operator tasks; the science goals of the mission were selected to advance the mainline research program of the principle investigator (PI). Training of the EOs was the responsibility of the PI team and consisted of laboratory sessions, on-site training during experiment integration, and integrated mission training using the aircraft as a high-fidelity simulator. The EO permission experience in these several disciplines proved adequate for normal experiment operations, but marginal for the identification and remedy of equipment malfunctions. During the mission, the PI utilized a TV communication system to assist the EOs to overcome equipment difficulties; both science and operations were successfully implemented.

  11. Chemistry characterization of jet aircraft engine particulate matter by XPS: Results from APEX III

    NASA Astrophysics Data System (ADS)

    Vander Wal, Randy L.; Bryg, Victoria M.; Huang, Chung-Hsuan

    2016-09-01

    This paper reports X-ray photoelectron spectroscopy (XPS) analysis of jet exhaust particulate matter (PM) from a B737, Lear, ERJ and A300 aircraft during the APEX III NASA led field campaign. Carbon hybridization and bonding chemistry are identified by high-resolution scans about the C1s core-shell region. Significant organic content as gauged by the sp3/sp2 ratio is found across engines and powers. Polar oxygen functional groups include carboxylic, carbonyl and phenol with combined content of 20% or more. By survey scans various elements including transition metals are identified along with lighter elements such as S, N and O in the form of oxides. Additives within lubricants are probable sources of Na, Ba, Ca, Zn, P and possibly Sn. Elements present and their percentages varied significantly across all engines, not revealing any trend or identifiable cause for the differences, though the origin is likely the same for the same element when observed. This finding suggests that their collective presence could serve as an environmental tracer for identifying PM originating from aircraft engines and serving as a diagnostic for engine performance and wear.

  12. Estimate of contribution of jet aircraft operations to trace element concentration at or near airports

    NASA Technical Reports Server (NTRS)

    Fordyce, J. S.; Sheibley, D. W.

    1975-01-01

    Samples of ASTM type A jet fuel were analyzed for trace element content by instrumental neutron activation techniques. Forty-nine elements were sought. Only ten, aluminum, gold, indium, lanthanum, titanium, vanadium, barium, dysprosium, tellurium, and uranium, were observed at levels above the detection limits encountered; of these only aluminum, titanium, and barium were present at concentrations greater than 0.1 ppm. Estimates of exhaust gas concentrations are made, and the ambient contribution at or near airports is calculated by using the Los Angeles International Airport dispersion model. It is shown that the ambient contribution is about an order of magnitude below typical urban levels for virtually all elements sought.

  13. Estimate of contribution of jet aircraft operations to trace element concentration at or near airports

    NASA Technical Reports Server (NTRS)

    Fordyce, J. S.; Sheibley, D. W.

    1974-01-01

    Samples of ASTM type A jet fuel were analyzed for trace-element content by instrumental neutron activation techniques. Forty-nine elements were sought. Only ten, aluminum, gold, indium, lanthanum, titanium, vandium, barium, dysprosium, tellurium, and uranium, were observed at levels above the detection limits encountered; of these only aluminum, titanium, and barium were present at concentrations greater than 0.1 ppm. Estimates of exhaust gas concentrations are made, and the ambient contribution at or near airports is calculated by using the Los Angeles International Airport dispersion model. It is shown that the ambient contribution is about an order of magnitude below typical urban levels for virtually all elements sought.

  14. Development of a reduced area horizontal tail for a wide body jet aircraft

    NASA Technical Reports Server (NTRS)

    Rising, Jerry J.

    1984-01-01

    Commercial transport aircraft fuel consumption can be significantly reduced by decreasing the size of the horizontal tail. Work on reducing the horizontal tail area of the L-1011 is discussed. The reduced area horizontal tail program consisted of design, fabrication and wind tunnel testing of horizontal tails with reduced planform areas of 30 to 38 percent relative to the standard L-1011 tail. The total drag of the aircraft in cruise was reduced by approximately 2 percent. However, it was necessary to impose forward center of gravity limitations on the aircraft because the maximum lift goal of the reduced area tail was not achieved and sufficient nose-up control authority was not available. On a new design this problem could have been solved by moving the landing gear aft and enlarging the cut-out in the aft fuselage to allow for larger horizontal stabilizer deflections. However, since this is an existing design, these modifications were unfeasible and resulted in the center of gravity restriction.

  15. Aircraft wing fuel tank environmental simulator tests for evaluation of antimisting fuels. Final report, September 1982-August 1984

    SciTech Connect

    McConnell, P.M.; Tolle, F.F.; Mehta, H.K.

    1984-10-01

    The low-temperature performance of antimisting kerosene (AMK) in airframe fuel systems and in certain fuel system components was studied and compared to Jet A fuel. Water vapor ingested into fuel tanks during simulation of repeated descents through clouds and rain had little effect on AMK. AMK retained antimisting properties during exposure to severe environmental flight simulations. Jet-pump and boost-pump operation had no discernible effect on AMK flammability. Jet-pump performance with AMK was adversely affected. Main fuel boost pumps required up to 18% more power with AMK that with Jet A, and suction-feed performance was lower with ambient and -20/sup 0/C, but better than Jet A and -40/sup 0/C. Boost-pump performance was not affected by gel formations produced at low temperatures by the vapor-removal return flow shearing of AMK. Aerodynamic heating and cooling of AMK in the fuel tank was similar to Jet A. A high-pressure pump and needle valve used to degrade the AMK was inadequate, resulting in filter bypass at low temperatures.

  16. 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.

  17. Control of flames by tangential jet actuators in oxy-fuel burners

    SciTech Connect

    Boushaki, Toufik; Sautet, Jean-Charles; Labegorre, Bernard

    2009-11-15

    The active control of oxy-fuel flames from burners with separated jets is investigated. The control system consists of four small jet actuators, placed tangential to the exit of the main jets to generate a swirling flow. These actuators are able to modify the flow structure and to act on mixing between the reactants and consequently on the flame behavior. The burner (25 kW) is composed of separated jets, one jet of natural gas and one or two jets of pure oxygen. Experiments are conducted with three burner configurations, according to the number of jets, the jet exit velocities, and the separation distance between the jets. OH chemiluminescence measurements, particle image velocimetry, and measurements of NO{sub x} emissions are used to characterize the flow and the flame structure. Results show that the small jet actuators have a significant influence on the behavior of jets and the flame characteristics, particularly in the stabilization zone. It is shown that the control leads to a decrease in lift-off heights and to better stability of the flame. The use of jet actuators induces high jet spreading and an increase in turbulence intensity, which improves the mixing between the reactants and the surrounding fluid. Pollutant measurements show important results in terms of NO{sub x} reductions (up to 60%), in particular for low swirl intensity. The burner parameters, such as the number of jets and the spacing between the jets, also impact the flame behavior and NO{sub x} formation. (author)

  18. Public health, climate, and economic impacts of desulfurizing jet fuel.

    PubMed

    Barrett, Steven R H; Yim, Steve H L; Gilmore, Christopher K; Murray, Lee T; Kuhn, Stephen R; Tai, Amos P K; Yantosca, Robert M; Byun, Daewon W; Ngan, Fong; Li, Xiangshang; Levy, Jonathan I; Ashok, Akshay; Koo, Jamin; Wong, Hsin Min; Dessens, Olivier; Balasubramanian, Sathya; Fleming, Gregg G; Pearlson, Matthew N; Wollersheim, Christoph; Malina, Robert; Arunachalam, Saravanan; Binkowski, Francis S; Leibensperger, Eric M; Jacob, Daniel J; Hileman, James I; Waitz, Ian A

    2012-04-17

    In jurisdictions including the US and the EU ground transportation and marine fuels have recently been required to contain lower concentrations of sulfur, which has resulted in reduced atmospheric SO(x) emissions. In contrast, the maximum sulfur content of aviation fuel has remained unchanged at 3000 ppm (although sulfur levels average 600 ppm in practice). We assess the costs and benefits of a potential ultra-low sulfur (15 ppm) jet fuel standard ("ULSJ"). We estimate that global implementation of ULSJ will cost US$1-4bn per year and prevent 900-4000 air quality-related premature mortalities per year. Radiative forcing associated with reduction in atmospheric sulfate, nitrate, and ammonium loading is estimated at +3.4 mW/m(2) (equivalent to about 1/10th of the warming due to CO(2) emissions from aviation) and ULSJ increases life cycle CO(2) emissions by approximately 2%. The public health benefits are dominated by the reduction in cruise SO(x) emissions, so a key uncertainty is the atmospheric modeling of vertical transport of pollution from cruise altitudes to the ground. Comparisons of modeled and measured vertical profiles of CO, PAN, O(3), and (7)Be indicate that this uncertainty is low relative to uncertainties regarding the value of statistical life and the toxicity of fine particulate matter.

  19. Conversion of microalgae to jet fuel: process design and simulation.

    PubMed

    Wang, Hui-Yuan; Bluck, David; Van Wie, Bernard J

    2014-09-01

    Microalgae's aquatic, non-edible, highly genetically modifiable nature and fast growth rate are considered ideal for biomass conversion to liquid fuels providing promise for future shortages in fossil fuels and for reducing greenhouse gas and pollutant emissions from combustion. We demonstrate adaptability of PRO/II software by simulating a microalgae photo-bio-reactor and thermolysis with fixed conversion isothermal reactors adding a heat exchanger for thermolysis. We model a cooling tower and gas floatation with zero-duty flash drums adding solids removal for floatation. Properties data are from PRO/II's thermodynamic data manager. Hydrotreating is analyzed within PRO/II's case study option, made subject to Jet B fuel constraints, and we determine an optimal 6.8% bioleum bypass ratio, 230°C hydrotreater temperature, and 20:1 bottoms to overhead distillation ratio. Process economic feasibility occurs if cheap CO2, H2O and nutrient resources are available, along with solar energy and energy from byproduct combustion, and hydrotreater H2 from product reforming. PMID:24997379

  20. Conversion of microalgae to jet fuel: process design and simulation.

    PubMed

    Wang, Hui-Yuan; Bluck, David; Van Wie, Bernard J

    2014-09-01

    Microalgae's aquatic, non-edible, highly genetically modifiable nature and fast growth rate are considered ideal for biomass conversion to liquid fuels providing promise for future shortages in fossil fuels and for reducing greenhouse gas and pollutant emissions from combustion. We demonstrate adaptability of PRO/II software by simulating a microalgae photo-bio-reactor and thermolysis with fixed conversion isothermal reactors adding a heat exchanger for thermolysis. We model a cooling tower and gas floatation with zero-duty flash drums adding solids removal for floatation. Properties data are from PRO/II's thermodynamic data manager. Hydrotreating is analyzed within PRO/II's case study option, made subject to Jet B fuel constraints, and we determine an optimal 6.8% bioleum bypass ratio, 230°C hydrotreater temperature, and 20:1 bottoms to overhead distillation ratio. Process economic feasibility occurs if cheap CO2, H2O and nutrient resources are available, along with solar energy and energy from byproduct combustion, and hydrotreater H2 from product reforming.

  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. Noise data for a twin-engine commercial jet aircraft flying conventional, steep, and two-segment approaches

    NASA Technical Reports Server (NTRS)

    Hastings, E. C., Jr.; Mueller, A. W.; Hamilton, J. R.

    1977-01-01

    Center-line noise measurements of a twin-engine commercial jet aircraft were made during steep landing approach profiles, and during two-segment approach profiles for comparison with similar measurements made during conventional approaches. The steep and two-segment approaches showed significant noise reductions when compared with the -3 deg base line. The measured noise data were also used to develop a method for estimating the noise under the test aircraft at thrust and altitude conditions typical of current landing procedures and of landing procedures under development for the Advanced Air Traffic Control System.

  3. Experimental study on spray characteristics of alternate jet fuels using Phase Doppler Anemometry

    NASA Astrophysics Data System (ADS)

    Kannaiyan, Kumaran; Sadr, Reza

    2013-11-01

    Gas-to-Liquid (GTL) fuels have gained global attention due to their cleaner combustion characteristics. The chemical and physical properties of GTL jet fuels are different from conventional jet fuels owing to the difference in their production methodology. It is important to study the spray characteristics of GTL jet fuels as the change of physical properties can affect atomization, mixing, evaporation and combustion process, ultimately affecting emission process. In this work, spray characteristics of two GTL synthetic jet fuels are studied using a pressure-swirl nozzle at different injection pressures and atmospheric ambient condition. Phase Doppler Anemometry (PDA) measurements of droplet size and velocity are compared with those of regular Jet A-1 fuel at several axial and radial locations downstream of the nozzle exit. Experimental results show that although the GTL fuels have different physical properties such as viscosity, density, and surface tension, among each other the resultant change in the spray characteristics is insignificant. Furthermore, the presented results show that GTL fuel spray characteristics exhibit close similarity to those of Jet A-1 fuel. Funded by Qatar Science and Technology Park.

  4. Characterization of jet breakup mechanisms observed from simulant experiments of molten fuel penetrating coolant

    SciTech Connect

    Jones, B.G.

    1992-01-01

    The goal of this research program has been to add to our understanding of the breakup of molten fuel jets penetrating reactor coolant. Easily handled working fluids are used to simulate fuel jet breakup, so that detailed observations may be obtained from a relatively large number of experiments. The tools used for observing this behavior are high speed notion picture photography, Flash X-radiography, and X-ray cine. Jet breakup lengths are determined from motion pictures; the mechanisms by which the jets are fragmented may be inferred from radiographs.

  5. Effects of Jet Fuel Spills on the Microbial Community of Soil †

    PubMed Central

    Song, Hong-Gyu; Bartha, Richard

    1990-01-01

    Hydrocarbon residues, microbial numbers, and microbial activity were measured and correlated in loam soil contaminated by jet fuel spills resulting in 50 and 135 mg of hydrocarbon g of soil−1. Contaminated soil was incubated at 27°C either as well-aerated surface soil or as poorly aerated subsurface soil. In the former case, the effects of bioremediation treatment on residues, microbial numbers, and microbial activity were also assessed. Hydrocarbon residues were measured by quantitative gas chromatography. Enumerations included direct counts of metabolically active bacteria, measurement of mycelial length, plate counts of aerobic heterotrophs, and most probable numbers of hydrocarbon degraders. Activity was assessed by fluorescein diacetate (FDA) hydrolysis. Jet fuel disappeared much more rapidly from surface soil than it did from subsurface soil. In surface soil, microbial numbers and mycelial length were increased by 2 to 2.5 orders of magnitude as a result of jet fuel contamination alone and by 3 to 4 orders of magnitude as a result of the combination of jet fuel contamination and bioremediation. FDA hydrolysis was stimulated by jet fuel and bioremediation, but was inhibited by jet fuel alone. The latter was traced to an inhibition of the FDA assay by jet fuel biodegradation products. In subsurface soil, oxygen limitation strongly attenuated microbial responses to jet fuel. An increase in the most probable numbers of hydrocarbon degraders was accompanied by a decline in other aerobic heterotrophs, so that total plate counts changed little. The correlations between hydrocarbon residues, microbial numbers, and microbial activity help in elucidating microbial contributions to jet fuel elimination from soil. PMID:16348138

  6. Quantitative degradation studies of coal derived jet fuel using statistical analysis

    SciTech Connect

    Sanghani, P.C.; Boehman, A.L.

    1996-10-01

    The kinetics of coke formation from coal-derived jet fuel were studied using statistical methods. The degree of correlation between deposit (coke) growth and species concentration has been examined. Formation of deposits from the mixtures of jet fuel and tetradecane was proportional to the initial concentration of tetradecane present in the fuel. Decomposition of tetradecane was found to be first order with con-elation coefficient of 0.98. Other normal alkanes species such as dodecane, tridecane, and pentadecane which are present in very small amount also contribute significantly to deposit growth. Cycloalkanes, alkylated c1,c2,c3 benzenes, alkylated naphathalenes present in coal derived jet fuel were very stable compared to tetradecane. The statistical approach helps in identifying or arranging species in terms of their contribution to deposit formation. Grouping species on the basis of their correlation with deposit formation clarifies the required structure for a general kinetic model of the jet fuel degradation process.

  7. 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.

  8. Advanced thermally stable jet fuels: Technical progress report, October 1994--December 1994

    SciTech Connect

    Schobert, H.H.; Eser, S.; Song, C.; Hatcher, P.G.; Boehman, A.; Coleman, M.M.

    1995-02-01

    There are five tasks within this project on thermally stable coal-based jet fuels. Progress on each of the tasks is described. Task 1, Investigation of the quantitative degradation chemistry of fuels, has 5 subtasks which are described: Literature review on thermal stability of jet fuels; Pyrolytic and catalytic reactions of potential endothermic fuels: cis- and trans-decalin; Use of site specific {sup 13}C-labeling to examine the thermal stressing of 1-phenylhexane: A case study for the determination of reaction kinetics in complex fuel mixtures versus model compound studies; Estimation of critical temperatures of jet fuels; and Surface effects on deposit formation in a flow reactor system. Under Task 2, Investigation of incipient deposition, the subtask reported is Uncertainty analysis on growth and deposition of particles during heating of coal-derived aviation gas turbine fuels; under Task 3, Characterization of solid gums, sediments, and carbonaceous deposits, is subtask, Studies of surface chemistry of PX-21 activated carbon during thermal degradation of jet A-1 fuel and n-dodecane; under Task 4, Coal-based fuel stabilization studies, is subtask, Exploratory screening and development potential of jet fuel thermal stabilizers over 400 C; and under Task 5, Exploratory studies on the direct conversion of coal to high quality jet fuels, are 4 subtasks: Novel approaches to low-severity coal liquefaction and coal/resid co-processing using water and dispersed catalysts; Shape-selective naphthalene hydrogenation for production of thermally stable jet fuels; Design of a batch mode and a continuous mode three-phase reactor system for the liquefaction of coal and upgrading of coal liquids; and Exploratory studies on coal liquids upgrading using mesopores molecular sieve catalysts. 136 refs., 69 figs., 24 tabs.

  9. Force and pressure characteristics for a series of nose inlets at Mach numbers from 1.59 to 1.99 V : analysis and comparison on basis of ram-jet aircraft range and operational characteristics

    NASA Technical Reports Server (NTRS)

    Howard, E; Luidens, R W; Allen, J L

    1951-01-01

    Performance of four experimentally investigated axially symmetric spike-type nose inlets is compared on basis of ram-jet-engine aircraft range and operational problems. At design conditions, calculated peak engine efficiencies varied 25 percent from the highest value which indicates importance of inlet design. Calculations for a typical supersonic aircraft indicate possible increase in range if engine is flown at moderate angle of attack and result in engine lift utilized. For engines with fixed exhaust nozzle, propulsive thrust increases with increasing heat addition in subcritical flow region in spite of increasing additive drag. For the perforated inlet there is a range of increasing total-temperature ratios in subcritical flow region that does not yield an increase in propulsive thrust. Effects of inlet characteristics on speed stability of a typical aircraft for three types of fuel control is discussed.

  10. Interior and exterior fuselage noise measured on NASA's C-8a augmentor wing jet-STOL research aircraft

    NASA Technical Reports Server (NTRS)

    Shovlin, M. D.

    1977-01-01

    Interior and exterior fuselage noise levels were measured on NASA's C-8A Augmentor Wing Jet-STOL Research Aircraft in order to provide design information for the Quiet Short-Haul Research Aircraft (QSRA), which will use a modified C-8A fuselage. The noise field was mapped by 11 microphones located internally and externally in three areas: mid-fuselage, aft fuselage, and on the flight deck. Noise levels were recorded at four power settings varying from takeoff to flight idle and were plotted in one-third octave band spectra. The overall sound pressure levels of the external noise field were compared to previous tests and found to correlate well with engine primary thrust levels. Fuselage values were 145 + or - 3 dB over the aircraft's normal STOL operating range.

  11. Computational Thermochemistry of Jet Fuels and Rocket Propellants

    NASA Technical Reports Server (NTRS)

    Crawford, T. Daniel

    2002-01-01

    The design of new high-energy density molecules as candidates for jet and rocket fuels is an important goal of modern chemical thermodynamics. The NASA Glenn Research Center is home to a database of thermodynamic data for over 2000 compounds related to this goal, in the form of least-squares fits of heat capacities, enthalpies, and entropies as functions of temperature over the range of 300 - 6000 K. The chemical equilibrium with applications (CEA) program written and maintained by researchers at NASA Glenn over the last fifty years, makes use of this database for modeling the performance of potential rocket propellants. During its long history, the NASA Glenn database has been developed based on experimental results and data published in the scientific literature such as the standard JANAF tables. The recent development of efficient computational techniques based on quantum chemical methods provides an alternative source of information for expansion of such databases. For example, it is now possible to model dissociation or combustion reactions of small molecules to high accuracy using techniques such as coupled cluster theory or density functional theory. Unfortunately, the current applicability of reliable computational models is limited to relatively small molecules containing only around a dozen (non-hydrogen) atoms. We propose to extend the applicability of coupled cluster theory- often referred to as the 'gold standard' of quantum chemical methods- to molecules containing 30-50 non-hydrogen atoms. The centerpiece of this work is the concept of local correlation, in which the description of the electron interactions- known as electron correlation effects- are reduced to only their most important localized components. Such an advance has the potential to greatly expand the current reach of computational thermochemistry and thus to have a significant impact on the theoretical study of jet and rocket propellants.

  12. Effect of Fuel Additives on Spray Performance of Alternative Jet Fuels

    NASA Astrophysics Data System (ADS)

    Kannaiyan, Kumaran; Sadr, Reza

    2015-11-01

    Role of alternative fuels on reducing the combustion pollutants is gaining momentum in both land and air transport. Recent studies have shown that addition of nanoscale metal particles as fuel additives to liquid fuels have a positive effect not only on their combustion performance but also in reducing the pollutant formation. However, most of those studies are still in the early stages of investigation with the addition of nanoparticles at low weight percentages. Such an addition can affect the hydrodynamic and thermo-physical properties of the fuel. In this study, the near nozzle spray performance of gas-to-liquid jet fuel with and without the addition of alumina nanoparticles are investigated at macro- and microscopic levels using optical diagnostic techniques. At macroscopic level, the addition of nanoparticles is seen to enhance the sheet breakup process when compared to that of the base fuel. Furthermore, the microscopic spray characteristics such as droplet size and velocity are also found to be affected. Although the addition of nanoscale metal particles at low weight percentages does not affect the bulk fluid properties, the atomization process is found to be affected in the near nozzle region. Funded by Qatar National Research Fund.

  13. Aircraft IR/acoustic detection evaluation. Volume 2: Development of a ground-based acoustic sensor system for the detection of subsonic jet-powered aircraft

    NASA Technical Reports Server (NTRS)

    Kraft, Robert E.

    1992-01-01

    The design and performance of a ground-based acoustic sensor system for the detection of subsonic jet-powered aircraft is described and specified. The acoustic detection system performance criteria will subsequently be used to determine target detection ranges for the subject contract. Although the defined system has never been built and demonstrated in the field, the design parameters were chosen on the basis of achievable technology and overall system practicality. Areas where additional information is needed to substantiate the design are identified.

  14. Advanced thermally stable jet fuels: Technical progress report, July 1994--September 1994

    SciTech Connect

    Schobert, H.H.; Eser, S.; Song, C.; Hatcher, P.G.; Boehman, A.; Coleman, M.M.

    1994-07-01

    There are five tasks within this project on thermally stable coal-based jet fuels. Progress on each of the tasks is described. Task 1, Investigation of the quantitative degradation chemistry of fuels, has 3 subtasks which are described: Pyrolysis of n-alkylbenzenes; Thermal decomposition of n-tetradecane in near-critical region; and Re-examining the effects of reactant and inert gas pressure on tetradecane pyrolysis--Effect of cold volume in batch reactor. Under Task 2, Investigation of incipient deposition, the subtask reported is Uncertainty analysis on growth and deposition of particles during heating of coal-derived aviation gas turbine fuels; under Task 3, Investigation of the quantitative degradation chemistry of fuels, is subtask, Effects of high surface area activated carbon and decalin on thermal degradation of jet A-1 fuel and n-dodecane; under Task 4, Coal-based fuel stabilization studies, is subtask, Screening potential jet fuel stabilizers using the model compound dodecane; and under Task 5, Exploratory studies on the direct conversion of coal to high quality jet fuels, is subtask, Shape-selective naphthalene hydrogenation for production of thermally stable jet fuels. 25 refs., 64 figs., 22 tabs.

  15. Effect of hydroprocessing severity on characteristics of jet fuel from OSCO 2 and Paraho distillates

    NASA Technical Reports Server (NTRS)

    Prok, G. M.; Flores, F. J.; Seng, G. T.

    1981-01-01

    Jet A boiling range fuels and broad-property research fuels were produced by hydroprocessing shale oil distillates, and their properties were measured to characterize the fuels. The distillates were the fraction of whole shale oil boiling below 343 C from TOSCO 2 and Paraho syncrudes. The TOSCO 2 was hydroprocessed at medium severity, and the Paraho was hydroprocessed at high, medium, and low severities. Fuels meeting Jet A requirements except for the freezing point were produced from the medium severity TOSCO 2 and the high severity Paraho. Target properties of a broad property research fuel were met by the medium severity TOSCO 2 and the high severity Paraho except for the freezing point and a high hydrogen content. Medium and low severity Paraho jet fuels did not meet thermal stability and freezing point requirements.

  16. Conversion of crop seed oils to jet fuel and associated methods

    DOEpatents

    Ginosar, Daniel M.; Petkovic, Lucia M.; Thompson, David N.

    2010-05-18

    Aspects of the invention include methods to produce jet fuel from biological oil sources. The method may be comprised of two steps: hydrocracking and reforming. The process may be self-sufficient in heat and hydrogen.

  17. Alternative aviation turbine fuels

    NASA Technical Reports Server (NTRS)

    Grobman, J.

    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 smoke and carbon formation, increased combustor liner temperatures, and poorer ignition characteristics. This paper discusses 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.

  18. 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.

  19. Hydrocarbon group type determination in jet fuels by high performance liquid chromatography

    NASA Technical Reports Server (NTRS)

    Antoine, A. C.

    1977-01-01

    Thirty-two jet and diesel fuel samples of varying chemical composition and physical properties were prepared from oil shale and coal syncrudes. Hydrocarbon types in these samples were determined by a fluorescent indicator adsorption analysis, and the results from three laboratories are presented and compared. Two methods of rapid high performance liquid chromatography were used to analyze some of the samples, and these results are also presented and compared. Two samples of petroleum-based Jet A fuel are similarly analyzed.

  20. Jet fuel deposition and oxidation: Dilution, materials, oxygen, and temperature effects

    SciTech Connect

    Zabarnick, S.; Zelesnik, P.; Grinstead, R.R.

    1996-04-01

    Quartz crystal microbalance (QCM) and pressure measurements are used for determination of jet fuel thermal stability in a batch reactor. The QCM is able to monitor extremely small amounts of deposition in situ, while the pressure measurements provide qualitative data on the oxidation process. The dependence of the deposition amount was monitored as a function of the oxygen availability for two fuels. Also, the effect of QCM electrode materials was investigated. Deposition and oxidation were compared for the following electrode materials: gold, aluminum, silver, and platinum. The authors also studied the effect of dilution on oxidation and deposition. Jet fuel was diluted with increasing amounts of hydrocarbon solvent. It was observed that this dilution procedure can help characterize a fuel`s effective antioxidant concentration. Fuel dilution is also shown to be a good technique for improving thermal stability characteristics of poor fuels. Additionally they have studied the temperature effect on deposition for two fuels over the range 140 to 180 C.

  1. Evaluation of skin sensitization potential of jet fuels by murine local lymph node assay.

    PubMed

    Kanikkannan, N; Jackson, T; Sudhan Shaik, M; Singh, M

    2000-07-27

    Jet A and JP-8 are the major jet fuels used in civilian and military (US Air Force) flights, respectively. JP-8+100 is a new jet fuel recently introduced by the US Air Force. Besides lung exposure, skin is the potential route of exposure to jet fuels. The purpose of the present study was to investigate the skin sensitization potential of jet fuels (Jet A, JP-8 and JP-8+100) using murine Local lymph node assay (LLNA). Female CBA/Ca mice (8-12-weeks-old) were used in the study. Dinitrochlorobenzene (DNCB, 0.25% w/v) and paraaminobenzoic acid (PABA, 2.5% w/v) were used as positive and negative control, respectively and acetone: olive oil (4:1, AOO) was used as the vehicle (control). All three jet fuels caused a proliferative activity significantly greater than the control (P<0.01). Our results demonstrate that JP-8 is a weak skin sensitizer [stimulation index (SI)=3.17]. The SI of Jet A and JP-8+100 were 2.44 and 2.38, respectively, hence are not considered as skin sensitizers. Interestingly, the SI of JP-8 with butylated hydroxytoluene (BHT) was consistently lower than JP-8, though the difference was not statistically significant (P>0.05). BHT, which is an antioxidant additive of JP-8+100, reduced the skin sensitization potential of JP-8. Furthermore, the lower SI of JP-8+100 could be partially attributed to the presence of BHT. The findings reported here suggest that care should be taken to minimize dermal exposure to jet fuels especially JP-8 to avoid skin sensitization.

  2. Biological and health effects of exposure to kerosene-based jet fuels and performance additives.

    PubMed

    Ritchie, Glenn; Still, Kenneth; Rossi, John; Bekkedal, Marni; Bobb, Andrew; Arfsten, Darryl

    2003-01-01

    Over 2 million military and civilian personnel per year (over 1 million in the United States) are occupationally exposed, respectively, to jet propulsion fuel-8 (JP-8), JP-8 +100 or JP-5, or to the civil aviation equivalents Jet A or Jet A-1. Approximately 60 billion gallon of these kerosene-based jet fuels are annually consumed worldwide (26 billion gallon in the United States), including over 5 billion gallon of JP-8 by the militaries of the United States and other NATO countries. JP-8, for example, represents the largest single chemical exposure in the U.S. military (2.53 billion gallon in 2000), while Jet A and A-1 are among the most common sources of nonmilitary occupational chemical exposure. Although more recent figures were not available, approximately 4.06 billion gallon of kerosene per se were consumed in the United States in 1990 (IARC, 1992). These exposures may occur repeatedly to raw fuel, vapor phase, aerosol phase, or fuel combustion exhaust by dermal absorption, pulmonary inhalation, or oral ingestion routes. Additionally, the public may be repeatedly exposed to lower levels of jet fuel vapor/aerosol or to fuel combustion products through atmospheric contamination, or to raw fuel constituents by contact with contaminated groundwater or soil. Kerosene-based hydrocarbon fuels are complex mixtures of up to 260+ aliphatic and aromatic hydrocarbon compounds (C(6) -C(17+); possibly 2000+ isomeric forms), including varying concentrations of potential toxicants such as benzene, n-hexane, toluene, xylenes, trimethylpentane, methoxyethanol, naphthalenes (including polycyclic aromatic hydrocarbons [PAHs], and certain other C(9)-C(12) fractions (i.e., n-propylbenzene, trimethylbenzene isomers). While hydrocarbon fuel exposures occur typically at concentrations below current permissible exposure limits (PELs) for the parent fuel or its constituent chemicals, it is unknown whether additive or synergistic interactions among hydrocarbon constituents, up to six

  3. Experimental and Modeling Studies of the Combustion Characteristics of Conventional and Alternative Jet Fuels. Final Report

    NASA Technical Reports Server (NTRS)

    Meeks, Ellen; Naik, Chitral V.; Puduppakkam, Karthik V.; Modak, Abhijit; Egolfopoulos, Fokion N.; Tsotsis, Theo; Westbrook, Charles K.

    2011-01-01

    The objectives of this project have been to develop a comprehensive set of fundamental data regarding the combustion behavior of jet fuels and appropriately associated model fuels. Based on the fundamental study results, an auxiliary objective was to identify differentiating characteristics of molecular fuel components that can be used to explain different fuel behavior and that may ultimately be used in the planning and design of optimal fuel-production processes. The fuels studied in this project were Fischer-Tropsch (F-T) fuels and biomass-derived jet fuels that meet certain specifications of currently used jet propulsion applications. Prior to this project, there were no systematic experimental flame data available for such fuels. One of the key goals has been to generate such data, and to use this data in developing and verifying effective kinetic models. The models have then been reduced through automated means to enable multidimensional simulation of the combustion characteristics of such fuels in real combustors. Such reliable kinetic models, validated against fundamental data derived from laminar flames using idealized flow models, are key to the development and design of optimal combustors and fuels. The models provide direct information about the relative contribution of different molecular constituents to the fuel performance and can be used to assess both combustion and emissions characteristics.

  4. 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...

  5. 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...

  6. 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...

  7. 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...

  8. Gaseous Species Measurements of Alternative Jet Fuels in Sooting Laminar Coflow Diffusion Flames

    NASA Astrophysics Data System (ADS)

    Zabeti, Parham

    The gaseous species concentration of Jet A-1, GTL, CTL and a blend of 80 vol.% GTL and 20 vol.% hexanol jet fuels in laminar coflow diffusion flames have been measured and studied. These species are carbon monoxide, carbon dioxide, oxygen, methane, ethane, ethylene, propylene, and acetylene. Benzene and propyne concentrations were also detected in CTL flames. 1-Butene has been quantified for the blend of GTL and hexanol flame. The detailed experimental setup has been described and results from different flames are compared. The CO is produced in a same amount in all the flames. The CTL flame had the largest and GTL/hexanol flame had lowest CO2 concentrations. The results indicate that GTL and GTL hexanol blend flames produce similar concentrations for all the measured hydrocarbon species and have the highest concentration among all the jet fuels. The experimental results from Jet A-1 fuel are also compared with numerical studies by Saffaripour et al .

  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. 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

  11. Effect of fuel density and heating value on ram-jet airplane range

    NASA Technical Reports Server (NTRS)

    Henneberry, Hugh M

    1952-01-01

    An analytical investigation of the effects of fuel density and heating value on the cruising range of a ram-jet airplane was made. Results indicate that with present-day knowledge of chemical fuels, neither very high nor very low fuel densities have any advantages for long-range flight. Of the fuels investigated, the borohydrides and metallic boron have the greatest range potential. Aluminum and aluminum hydrocarbon slurries were inferior to pure hydrocarbon fuel and boron-hydrocarbon slurries were superior on a range basis. It was concluded that the practical difficulties associated with the use of liquid hydrogen fuel cannot be justified on a range basis.

  12. Future aviation fuels overview

    NASA Technical Reports Server (NTRS)

    Reck, G. M.

    1980-01-01

    The outlook for aviation fuels through the turn of the century is briefly discussed and the general objectives of the NASA Lewis Alternative Aviation Fuels Research Project are outlined. The NASA program involves the evaluation of potential characteristics of future jet aircraft fuels, the determination of the effects of those fuels on engine and fuel system components, and the development of a component technology to use those fuels.

  13. 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.

  14. Development of an advanced pitch active control system for a wide body jet aircraft

    NASA Technical Reports Server (NTRS)

    Guinn, Wiley A.; Rising, Jerry J.; Davis, Walt J.

    1984-01-01

    An advanced PACS control law was developed for a commercial wide-body transport (Lockheed L-1011) by using modern control theory. Validity of the control law was demonstrated by piloted flight simulation tests on the NASA Langley visual motion simulator. The PACS design objective was to develop a PACS that would provide good flying qualities to negative 10 percent static stability margins that were equivalent to those of the baseline aircraft at a 15 percent static stability margin which is normal for the L-1011. Also, the PACS was to compensate for high-Mach/high-g instabilities that degrade flying qualities during upset recoveries and maneuvers. The piloted flight simulation tests showed that the PACS met the design objectives. The simulation demonstrated good flying qualities to negative 20 percent static stability margins for hold, cruise and high-speed flight conditions. Analysis and wind tunnel tests performed on other Lockheed programs indicate that the PACS could be used on an advanced transport configuration to provide a 4 percent fuel savings which results from reduced trim drag by flying at negative static stability margins.

  15. Jet A fuel recovery using micellar flooding: Design and implementation.

    PubMed

    Kostarelos, Konstantinos; Lenschow, Søren R; Stylianou, Marinos A; de Blanc, Phillip C; Mygind, Mette Marie; Christensen, Anders G

    2016-09-01

    Surfactants offer two mechanisms for recovering NAPLs: 1) to mobilize NAPL by reducing NAPL/water interfacial tension, and; 2) to increase the NAPL's aqueous solubility-called solubilization-as an enhancement to pump & treat. The second approach has been well-studied and applied successfully in several pilot-scale and a few full-scale tests within the last 15years, known as Surfactant Enhanced Aquifer Remediation (SEAR). A useful source of information for this second approach is the "Surfactant-enhanced aquifer remediation (SEAR) design manual" from the U.S. Navy Facilities Engineering Command. Few attempts, however, have been made at recovering NAPLs using the mobilization approach presented in this paper. Now, a full-scale field implementation of the mobilization approach is planned to recover an LNAPL (Jet A fuel) from a surficial sand aquifer located in Denmark using a smaller amount of surfactant solution and fewer PVs of throughput compared with the SEAR approach. The approach will rely on mobilizing the LNAPL so that it is recovered ahead of the surfactant microemulsion, also known as a micellar flood. This paper will review the laboratory work performed as part of the design for a full-scale implementation of a micellar flood. Completed lab work includes screening of surfactants, phase behavior and detailed salinity scans of the most promising formulations, and generating a ternary diagram to be used for the numerical simulations of the field application. The site owners and regulators were able to make crucial decisions such as the anticipated field results based on this work.

  16. 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.

  17. 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.

  18. Comparison of Global Sizing Velocimetry and Phase Doppler Anemometry measurements of alternative jet fuel sprays

    NASA Astrophysics Data System (ADS)

    Sadr, Reza; Kannaiyan, Kumaran

    2013-11-01

    Atomization plays a crucial precursor role in liquid fuel combustion that directly affects the evaporation, mixing, and emission levels. Laser diagnostic techniques are often used to study the spray characteristics of liquid fuels. The objective of this work is to compare the spray measurements of Gas-to Liquid (GTL) jet fuels obtained using Global Sizing Velocimetry (GSV) and Phase Doppler Anemometry (PDA) techniques at global and local levels, respectively. The chemical and physical properties of GTL fuels are different from conventional jet fuels, owing to the difference in their production methodology. In this work, the experimental facility, the measurement techniques, and spray characteristics of two different GTL fuels are discussed and compared with those of Jet A-1 fuel. Results clearly demonstrate that although the global measurement gives an overall picture of the spray, fine details are obtained only through local measurements and complement in gaining more inferences into the spray characteristics. The results also show a close similarity in spray characteristics between GTL and Jet A-1 fuels. Funded by Qatar Science and Technology Park.

  19. Cost and fuel consumption per nautical mile for two engine jet transports using OPTIM and TRAGEN

    NASA Technical Reports Server (NTRS)

    Wiggs, J. F.

    1982-01-01

    The cost and fuel consumption per nautical mile for two engine jet transports are computed using OPTIM and TRAGEN. The savings in fuel and direct operating costs per nautical mile for each of the different types of optimal trajectories over a standard profile are shown.

  20. Oilseeds for use in biodiesel and drop-in renewable jet fuel

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Oilseeds, primarily soybean and canola, are currently used as feedstocks for biodiesel production. Oilseeds can also be used to produce drop-in renewable jet fuel and diesel products. While soybean and canola are the most common oilseed crops used for renewable fuel production in the U.S., many othe...

  1. BREATH MEASUREMENT OF TOTAL BODY BURDEN OF JP-8 JET FUEL FOR EPIDEMIOLOGICAL STUDY

    EPA Science Inventory

    A complex epidemiological investigation of the effects of acute exposure to JP-8 jet fuel in the U.S. Air Force was performed through the study of about 350 human subjects across six Air Force bases. The focus was on fuels system maintenance personnel as the "exposed"...

  2. Opportunities and challenges for developing an oilseed to renewable jet fuel industry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Military and commercial aviation have expressed interest in using renewable aviation biofuels, with an initial goal of 1 billion gallons of drop-in aviation biofuels by 2018. While these fuels could come from many sources, hydrotreated renewable jet fuel (HRJ) from vegetable oils have been demonstra...

  3. PROTOZOA IN SUBSURFACE SEDIMENTS FROM SITE CONTAMI- NATED WITH AVIATION GASOLINE OR JET FUEL

    EPA Science Inventory

    Numbers of protozoa in the subsurface of aviation gasoline and jet fuel spill areas at a Coast Guard base at Traverse City, Mich., were determined. Boreholes were drilled in an uncontaminated location, in contaminated but untreated parts of the fuel plumes, and in the aviation ga...

  4. 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.

  5. Parametric performance of a turbojet engine combustor using jet A and A diesel fuel

    NASA Technical Reports Server (NTRS)

    Butze, H. F.; Humenik, F. M.

    1979-01-01

    The performance of a single-can JT8D combustor was evaluated with Jet A and a high-aromatic diesel fuel over a parametric range of combustor-inlet conditions. Performance parameters investigated were combustion efficiency, emissions of CO, unburned hydrocarbons, and NOx, as well as liner temperatures and smoke. At all conditions the use of diesel fuel instead of Jet A resulted in increases in smoke numbers and liner temperatures; gaseous emissions, on the other hand, did not differ significantly between the two fuels.

  6. Full-scale wind-tunnel tests of a small unpowered jet aircraft with a T-tail

    NASA Technical Reports Server (NTRS)

    Soderman, P. T.; Aiken, T. N.

    1971-01-01

    The aerodynamic characteristics of a full scale executive type jet transport aircraft with a T-tail were investigated in a 40 x 80 ft (12.2 by 24.4 meter) wind tunnel (subsonic). Static, longitudinal, and lateral stability, and control characteristics were determined at angles of attack from -2 deg to +42 deg. The aircraft wing had 13 deg of sweep and an aspect ratio of 5.02. The aircraft was tested power off with various wing leading- and trailing-edge high lift devices. The basic configuration was tested with and without such components as engine nacelles, wing tip tanks, and empannage. Hinge-moment data were obtained and downwash angles in the horizontal-tail plane location were calculated. The data were obtained at Reynolds numbers of 4.1 million and 8.7 million based on mean aerodynamic chord. The model had static longitudinal stability through initial stall. Severe tail buffet occurred near the angle of attack for maximum lift. Above initial stall the aircraft had pronounced pitch-up, characteristic of T-tail configurations. A stable trim point was possible at angles of attack between 30 deg and 40 deg (depending on c.g. location and flap setting). Hinge-moment data showed no regions with adverse effects on stick force. Comparisons of wind-tunnel data and flight-test are presented.

  7. Sulfuric acid measurements in the exhaust plume of a jet aircraft in flight: Implications for the sulfuric acid formation efficiency

    NASA Astrophysics Data System (ADS)

    Curtius, J.; Arnold, F.; Schulte, P.

    2002-04-01

    Sulfuric acid concentrations were measured in the exhaust plume of a B737-300 aircraft in flight. The measurements were made onboard of the German research aircraft Falcon using the Volatile Aerosol Component Analyzer (VACA). The VACA measures total H2SO4, which is the sum of gaseous H2SO4 and aerosol H2SO4. Measurements took place at distances of 25-200 m behind the B737 corresponding to plume ages of about 0.1-1 seconds. The fuel sulfur content (FSC) of the fuel burned by the B737 engines was alternatively 2.6 and 56 mg sulfur per kilogram fuel (ppmm). H2SO4 concentrations measured in the plume for the 56 ppmm sulfur case were up to ~600 pptv. The average concentration of H2SO4 measured in the ambient atmosphere outside the aircraft plume was 88 pptv, the maximum ambient atmospheric H2SO4 was ~300 pptv. Average efficiencies ɛΔCO2 = 3.3 +/- 1.8% and ɛΔT = 2.9 +/- 1.6% for fuel sulfur conversion to sulfuric acid were inferred when relating the H2SO4 data to measurements of the plume tracers ΔCO2 and ΔT.

  8. 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…

  9. The Simulation of a Jumbo Jet Transport Aircraft. Volume 2: Modeling Data

    NASA Technical Reports Server (NTRS)

    Hanke, C. R.; Nordwall, D. R.

    1970-01-01

    The manned simulation of a large transport aircraft is described. Aircraft and systems data necessary to implement the mathematical model described in Volume I and a discussion of how these data are used in model are presented. The results of the real-time computations in the NASA Ames Research Center Flight Simulator for Advanced Aircraft are shown and compared to flight test data and to the results obtained in a training simulator known to be satisfactory.

  10. Advanced thermally stable jet fuels. Technical progress report, April 1994--June 1994

    SciTech Connect

    Schobert, H.H.; Eser, S.; Song, C.

    1994-07-01

    Research continued on coal-based, thermally stable, jet fuels. Significant progress has been made on the detection of polycyclic aromatic hydrocarbons present in highly stressed fuels, using high-performance liquid chromatography (HPLC) with diode-array detection. Gas chromatography is not able to detect compounds with {>=}6 fused aromatic rings, but such compounds can be identified using the HPLC method. The concentration of such compounds is low in comparison to aromatics of 1-3 rings, but the role of the large compounds in the formation of solid deposits may be crucial in determining the thermal stability of a fuel. The unusual properties of fluid fuels in the near-critical region appear to have significant effects on their thermal decomposition reactions. This issue has been investigated in the present reporting period using n-tetradecane as a model compound for fuel decomposition. Temperature-programmed retention indices are very useful for gas chromatographic and gas chromatography/mass spectrometric analysis of coal and petroleum derived jet fuels. We have demonstrated this in the identification of components in two JP-8 fuels and their liquid chromatographic fractions. The role of activated carbon surfaces as catalysts in the thermal stressing of jet fuel was investigated using n-dodecane and n-octane as model compounds. In some cases the reactions were spiked with addition of 5% decalin to test the ability of the carbon to catalyze the transformation of decalin to naphthalene. We have previously shown that benzyl alcohol and 1,4-benzenedimethanol are effective stabilizers at temperatures {>=}400{degrees}C for jet fuels and the model compound dodecane. The addition of ethanol to hydrocarbon/benzyl alcohol mixtures has a significant effect on the thermal stabilization of jet fuels above 400{degrees}C. Ethanol appears to function by reducing the benzaldehyde formed during the degradation of the benzyl alcohol. This reduction regenerates the benzyl alcohol.

  11. Fundamentals of the Control of Gas-Turbine Power Plants for Aircraft. Part 2; Principles of Control Common to Jet, Turbine-Propeller Jet, and Ducted-Fan Jet Power Plants

    NASA Technical Reports Server (NTRS)

    Kuehl, H.

    1947-01-01

    After defining the aims and requirements to be set for a control system of gas-turbine power plants for aircraft, the report will deal with devices that prevent the quantity of fuel supplied per unit of time from exceeding the value permissible at a given moment. The general principles of the actuation of the adjustable parts of the power plant are also discussed.

  12. Numeric Design and Performance Analysis of Solid Oxide Fuel Cell -- Gas Turbine Hybrids on Aircraft

    NASA Astrophysics Data System (ADS)

    Hovakimyan, Gevorg

    The aircraft industry benefits greatly from small improvements in aircraft component design. One possible area of improvement is in the Auxiliary Power Unit (APU). Modern aircraft APUs are gas turbines located in the tail section of the aircraft that generate additional power when needed. Unfortunately the efficiency of modern aircraft APUs is low. Solid Oxide Fuel Cell/Gas Turbine (SOFC/GT) hybrids are one possible alternative for replacing modern gas turbine APUs. This thesis investigates the feasibility of replacing conventional gas turbine APUs with SOFC/GT APUs on aircraft. An SOFC/GT design algorithm was created in order to determine the specifications of an SOFC/GT APU. The design algorithm is comprised of several integrated modules which together model the characteristics of each component of the SOFC/GT system. Given certain overall inputs, through numerical analysis, the algorithm produces an SOFC/GT APU, optimized for specific power and efficiency, capable of performing to the required specifications. The SOFC/GT design is then input into a previously developed quasi-dynamic SOFC/GT model to determine its load following capabilities over an aircraft flight cycle. Finally an aircraft range study is conducted to determine the feasibility of the SOFC/GT APU as a replacement for the conventional gas turbine APU. The design results show that SOFC/GT APUs have lower specific power than GT systems, but have much higher efficiencies. Moreover, the dynamic simulation results show that SOFC/GT APUs are capable of following modern flight loads. Finally, the range study determined that SOFC/GT APUs are more attractive over conventional APUs for longer range aircraft.

  13. Refining and blending of aviation turbine fuels.

    PubMed

    White, R D

    1999-02-01

    Aviation turbine fuels (jet fuels) are similar to other petroleum products that have a boiling range of approximately 300F to 550F. Kerosene and No.1 grades of fuel oil, diesel fuel, and gas turbine oil share many similar physical and chemical properties with jet fuel. The similarity among these products should allow toxicology data on one material to be extrapolated to the others. Refineries in the USA manufacture jet fuel to meet industry standard specifications. Civilian aircraft primarily use Jet A or Jet A-1 fuel as defined by ASTM D 1655. Military aircraft use JP-5 or JP-8 fuel as defined by MIL-T-5624R or MIL-T-83133D respectively. The freezing point and flash point are the principle differences between the finished fuels. Common refinery processes that produce jet fuel include distillation, caustic treatment, hydrotreating, and hydrocracking. Each of these refining processes may be the final step to produce jet fuel. Sometimes blending of two or more of these refinery process streams are needed to produce jet fuel that meets the desired specifications. Chemical additives allowed for use in jet fuel are also defined in the product specifications. In many cases, the customer rather than the refinery will put additives into the fuel to meet their specific storage or flight condition requirements.

  14. Dermal exposure to jet fuel suppresses delayed-type hypersensitivity: a critical role for aromatic hydrocarbons.

    PubMed

    Ramos, Gerardo; Limon-Flores, Alberto Yairh; Ullrich, Stephen E

    2007-12-01

    Dermal exposure to military (JP-8) and/or commercial (Jet-A) jet fuel suppresses cell-mediated immune reactions. Immune regulatory cytokines and biological modifiers, including platelet activating factor (PAF), prostaglandin E(2), and interleukin-10, have been implicated in the pathway of events leading to immune suppression. It is estimated that approximately 260 different hydrocarbons are found in jet fuel, and the exact identity of the active immunotoxic agent(s) is unknown. The recent availability of synthetic jet fuel (S-8), which is refined from natural gas, and is devoid of aromatic hydrocarbons, made it feasible to design experiments to address this problem. Here we tested the hypothesis that the aromatic hydrocarbons present in jet fuel are responsible for immune suppression. We report that applying S-8 to the skin of mice does not upregulate the expression of epidermal cyclooxygenase-2 (COX-2) nor does it induce immune suppression. Adding back a cocktail of seven of the most prevalent aromatic hydrocarbons found in jet fuel (benzene, toluene, ethylbenzene, xylene, 1,2,4-trimethlybenzene, cyclohexylbenzene, and dimethylnaphthalene) to S-8 upregulated epidermal COX-2 expression and suppressed a delayed-type hypersensitivity (DTH) reaction. Injecting PAF receptor antagonists, or a selective cycloozygenase-2 inhibitor into mice treated with S-8 supplemented with the aromatic cocktail, blocked suppression of DTH, similar to data previously reported using JP-8. These findings identify the aromatic hydrocarbons found in jet fuel as the agents responsible for suppressing DTH, in part by the upregulation of COX-2, and the production of immune regulatory factors and cytokines.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. Fuel conservative guidance for shipboard landing of powered-lift STOL aircraft

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

    A computer-simulation study was undertaken to investigate the application of Fuel Conservative Guidance (FCG) techniques, developed at NASA Ames Research Center, to improve the fuel efficiency and minimize recovery time of powered-lift short-takeoff-and-landing (STOL) airplanes operating from aircraft carriers at sea. The FCG system consists of a set of algorithms whose coefficients and parameters limits match those of the Quiet Short-Haul Research Aircraft. When a flightpath is specified by a set of initial conditions for the aircraft and a set of positional waypoints with associated airspeeds, the FCG synthesizes the necessary guidance commands to capture the specified path at any specified waypoint and to optimize fuel consumption and time fo fly along the path. Closed-form expressions are developed for calculating the altitude profile synthesized by the algorithm. 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 38 percent (434 lb of fuel) and the time required to fly the flightpath was reduced by as much as 28 percent (209 sec). Savings because of FCG were produced by: (1) shortening the total flight time and distance, and (2) keeping the airspeed high as long as possible to minimize time spent flying in a powered-lift mode.

  20. Investigations of transonic buffet control on civil aircraft wing with the use of tangential jet blowing

    NASA Astrophysics Data System (ADS)

    Abramova, K. A.; Petrov, A. V.; Potapchick, A. V.; Soudakov, V. G.

    2016-10-01

    Numerical and experimental investigations of transonic buffet control by tangential jet blowing are presented. To suppress the shock-induced boundary layer separation and the buffet at transonic speeds, compressed air jet is blown through a small slot nozzle tangentially to the upper surface of the supercritical airfoil. Numerical simulations were carried out on the basis of the unsteady Reynolds averaged Navier-Stokes (URANS) equations. Experimental studies of the tangential jet blowing were performed in the transonic wind tunnel T-112 of TsAGI. Results show that the jet moves the shock downstream, increases lift, suppresses flow separation under shock foot and delays buffet onset.

  1. Effect of crossflow velocity on the generation of lift fan jet noise in VTOL aircraft

    NASA Technical Reports Server (NTRS)

    Stimpert, D. L.; Fogg, R. G.

    1973-01-01

    Analytical studies based on a turbulent mixing noise prediction technique indicate that jet noise power levels are increased when a jet is situated in a crossflow. V/STOL model transport acoustic test data obtained in the NASA Ames 40 ft. x 80 ft. wind tunnel confirmed this jet noise power level increase due to crossflow. Increases up to 6 db at a Strouhal number of 2.5 and crossflow velocity to jet velocity ratio of 0.58 were observed. The power level increases observed in the experimental data confirm the predicted power level increases.

  2. Exposure to low levels of jet-propulsion fuel impairs brainstem encoding of stimulus intensity.

    PubMed

    Guthrie, O'neil W; Xu, Helen; Wong, Brian A; McInturf, Shawn M; Reboulet, Jim E; Ortiz, Pedro A; Mattie, David R

    2014-01-01

    Jet propulsion fuel-8 (JP-8) is a kerosene-based fuel that is used in military jets. The U.S. Armed Services and North Atlantic Treaty Organization countries adopted JP-8 as a standard fuel source and the U.S. military alone consumes more than 2.5 billion gallons annually. Preliminary epidemiologic data suggested that JP-8 may interact with noise to induce hearing loss, and animal studies revealed damage to presynaptic sensory cells in the cochlea. In the current study, Long-Evans rats were divided into four experimental groups: control, noise only, JP-8 only, and JP-8 + noise. A subototoxic level of JP-8 was used alone or in combination with a nondamaging level of noise. Functional and structural assays of the presynaptic sensory cells combined with neurophysiologic studies of the cochlear nerve revealed that peripheral auditory function was not affected by individual exposures and there was no effect when the exposures were combined. However, the central auditory nervous system exhibited impaired brainstem encoding of stimulus intensity. These findings may represent important and major shifts in the theoretical framework that governs current understanding of jet fuel and/or jet fuel + noise-induced ototoxicity. From an epidemiologic perspective, results indicate that jet fuel exposure may exert consequences on auditory function that may be more widespread and insidious than what was previously shown. It is possible that a large population of military personnel who are suffering from the effects of jet fuel exposure may be misidentified because they would exhibit normal hearing thresholds but harbor a "hidden" brainstem dysfunction.

  3. Application of digital human modeling and simulation for vision analysis of pilots in a jet aircraft: a case study.

    PubMed

    Karmakar, Sougata; Pal, Madhu Sudan; Majumdar, Deepti; Majumdar, Dhurjati

    2012-01-01

    Ergonomic evaluation of visual demands becomes crucial for the operators/users when rapid decision making is needed under extreme time constraint like navigation task of jet aircraft. Research reported here comprises ergonomic evaluation of pilot's vision in a jet aircraft in virtual environment to demonstrate how vision analysis tools of digital human modeling software can be used effectively for such study. Three (03) dynamic digital pilot models, representative of smallest, average and largest Indian pilot population were generated from anthropometric database and interfaced with digital prototype of the cockpit in Jack software for analysis of vision within and outside the cockpit. Vision analysis tools like view cones, eye view windows, blind spot area, obscuration zone, reflection zone etc. were employed during evaluation of visual fields. Vision analysis tool was also used for studying kinematic changes of pilot's body joints during simulated gazing activity. From present study, it can be concluded that vision analysis tool of digital human modeling software was found very effective in evaluation of position and alignment of different displays and controls in the workstation based upon their priorities within the visual fields and anthropometry of the targeted users, long before the development of its physical prototype.

  4. Advanced thermally stable jet fuels. Technical progress report, April 1995--June 1995

    SciTech Connect

    Schobert, H.H.; Eser, S.; Boehman, A.; Song, C.

    1995-08-01

    Research continued on thermally stable jet fuel from coal liquids and petroleum distillates. The oxidative and thermal stabilities of ten fuels have been studied by differential scanning calorimetry and in microautoclave reactors. The compositions of the stressed fuels (as well as the unreacted fuels) were characterized by gas chromatography and gas chromatography/mass spectrometry. In addition, simulated distillation curves were determined by thermogravimetric analysis. The product distributions and reaction mechanisms for the thermal decomposition of n-alkanes in near-critical and supercritical regions were studied. The emphasis of the work in this reporting period has been placed on reaction mechanisms and product distributions. Work is continuing on obtaining additional {sup 13}C-labeled jet fuel components for future thermal stressing studies. Compounds of current interest include 6-{sup 13}C-dodecane and 1-cyclohexyl-1-{sup 13}C-hexane. Further analysis of the formation of solids from the thermal stressing of decane and decalin has been performed.

  5. 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.

  6. Hydrocarbons (Jet Fuel JP-8) Induce Epigenetic Transgenerational Inheritance of Obesity, Reproductive Disease and Sperm Epimutations

    PubMed Central

    Tracey, Rebecca; Manikkam, Mohan; Guerrero-Bosagna, Carlos; Skinner, Michael K.

    2012-01-01

    Environmental compounds have been shown to promote epigenetic transgenerational inheritance of disease. The current study was designed to determine if a hydrocarbon mixture involving jet fuel (JP-8) promotes epigenetic transgenerational inheritance of disease. Gestating F0 generation female rats were transiently exposed during the fetal gonadal development period. The direct exposure F1 generation had an increased incidence of kidney abnormalities in both females and males, prostate and pubertal abnormalities in males, and primordial follicle loss and polycystic ovarian disease in females. The first transgenerational generation is the F3 generation, and the jet fuel lineage had an increased incidence of primordial follicle loss and polycystic ovarian disease in females, and obesity in both females and males. Analysis of the jet fuel lineage F3 generation sperm epigenome identified 33 differential DNA methylation regions, termed epimutations. Observations demonstrate hydrocarbons can promote epigenetic transgenerational inheritance of disease and sperm epimutations, potential biomarkers for ancestral exposures. PMID:23453003

  7. Performance of in situ soil venting system at jet fuel spill site

    SciTech Connect

    DePaoli, D.W.; Herbes, S.E.; Elliott, M.G.

    1989-01-01

    The Air Force Engineering and Services Center and Oak Ridge National Laboratory (ORNL) are performing a field demonstration of in situ venting at a 27,000-gal jet fuel spill site at Hill Air Force Base (AFB), Utah. In situ soil venting is a soil cleanup techniques that uses vacuum blowers to pull large volumes of air through contaminated soil. The air flow sweeps out the soil gas, disrupting the equilibrium existing between the contaminants on the soil and in the vapor. This causes volatilization of the contaminant and subsequent removal in the air stream. In situ soil venting has been used for removing volatile contaminants such as gasoline and trichloroethylene, but a full-scale demonstration for removing jet fuel from soil has not been reported. This paper briefly describes the jet fuel spill site and the design and results to date of our full-scale in situ soil venting system. 8 refs., 9 figs.

  8. Development of an Impinging-jet Fuel-injection Valve Nozzle

    NASA Technical Reports Server (NTRS)

    Spanogle, J A; Hemmeter, G H

    1931-01-01

    During an investigation to determine the possibilities and limitations of a two-stroke-cycle engine and ignition, it was necessary to develop a fuel injection valve nozzle to produce a disk-shaped, well dispersed spray. Preliminary tests showed that two smooth jets impinging upon each other at an angle of 74 degrees gave a spray with the desired characteristics. Nozzles were built on this basis and, when used in fuel-injection valves, produced a spray that fulfilled the original requirements. The spray is so well dispersed that it can be carried along with an air stream of comparatively low velocity or entrained with the fuel jet from a round-hole orifice. The characteristics of the spray from an impinging-jet nozzle limits its application to situations where wide dispersion is required by the conditions in the engine cylinder and the combustion chamber.

  9. Jet Fuel Kerosene is not Immunosuppressive in Mice or Rats Following Inhalation for 28 Days

    PubMed Central

    White, Kimber L.; DeLorme, Michael P.; Beatty, Patrick W.; Smith, Matthew J.; Peachee, Vanessa L.

    2013-01-01

    Previous reports indicated that inhalation of JP-8 aviation turbine fuel is immunosuppressive. However, in some of those studies, the exposure concentrations were underestimated, and percent of test article as vapor or aerosol was not determined. Furthermore, it is unknown whether the observed effects are attributable to the base hydrocarbon fuel (jet fuel kerosene) or to the various fuel additives in jet fuels. The present studies were conducted, in compliance with Good Laboratory Practice (GLP) regulations, to evaluate the effects of jet fuel kerosene on the immune system, in conjunction with an accurate, quantitative characterization of the aerosol and vapor exposure concentrations. Two female rodent species (B6C3F1 mice and Crl:CD rats) were exposed by nose-only inhalation to jet fuel kerosene at targeted concentrations of 0, 500, 1000, or 2000 mg/m3 for 6 h daily for 28 d. Humoral, cell-mediated, and innate immune functions were subsequently evaluated. No marked effects were observed in either species on body weights, spleen or thymus weights, the T-dependent antibody-forming cell response (plaque assay), or the delayed-type hypersensitivity (DTH) response. With a few exceptions, spleen cell numbers and phenotypes were also unaffected. Natural killer (NK) cell activity in mice was unaffected, while the NK assessment in rats was not usable due to an unusually low response in all groups. These studies demonstrate that inhalation of jet fuel kerosene for 28 d at levels up to 2000 mg/m3 did not adversely affect the functional immune responses of female mice and rats. PMID:24028664

  10. 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.

  11. A preliminary look at an optimal multivariable design for propulsion-only flight control of jet-transport aircraft

    NASA Technical Reports Server (NTRS)

    Azzano, Christopher P.

    1992-01-01

    Control of a large jet transport aircraft without the use of conventional control surfaces was studied. Engine commands were used to attempt to recreate the forces and moments typically provided by the elevator, ailerons, and rudder. Necessary conditions for aircraft controllability were developed pertaining to aircraft configuration such as the number of engines and engine placement. An optimal linear quadratic regulator controller was developed for the Boeing 707-720, in particular, for regulation of its natural dynamic modes. The design used a method of assigning relative weights to the natural modes, i.e., phugoid and dutch roll, for a more intuitive selection of the cost function. A prototype pilot command interface was then integrated into the loop based on pseudorate command of both pitch and roll. Closed loop dynamics were evaluated first with a batch linear simulation and then with a real time high fidelity piloted simulation. The NASA research pilots assisted in evaluation of closed loop handling qualities for typical cruise and landing tasks. Recommendations for improvement on this preliminary study of optimal propulsion only flight control are provided.

  12. 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.

  13. Feasibility of Producing and Using Biomass-Based Diesel and Jet Fuel in the United States

    SciTech Connect

    Milbrandt, A.; Kinchin, C.; McCormick, R.

    2013-12-01

    The study summarizes the best available public data on the production, capacity, cost, market demand, and feedstock availability for the production of biomass-based diesel and jet fuel. It includes an overview of the current conversion processes and current state-of-development for the production of biomass-based jet and diesel fuel, as well as the key companies pursuing this effort. Thediscussion analyzes all this information in the context of meeting the RFS mandate, highlights uncertainties for the future industry development, and key business opportunities.

  14. Progress on coal-derived fuels for aviation systems

    NASA Technical Reports Server (NTRS)

    Witcofski, R. D.

    1978-01-01

    Synthetic aviation kerosene (Syn. Jet-A), liquid methane (LCH4), and liquid hydrogen (LH2) appear to be the most promising coal-derived fuels. Liquid hydrogen aircraft configurations, their fuel systems, and their ground requirements at the airport are identified. These aircraft appear viable, particularly for long haul use, where aircraft fueled with coal derived LH2 would consume 9 percent less coal resources than would aircraft fueled with coal derived Syn. Jet-A. Distribution of hydrogen from the point of manufacture to airports may pose problems. Synthetic JET-A would appear to cause fewer concerns to the air transportation industry. Of the three candidate fuels, LCH4 is the most energy efficient to produce, and an aircraft fueled with coal derived LCH4 may provide both the most efficient utilization of coal resources and the least expensive ticket as well.

  15. Soviet aerospace industry - Propulsion research center focuses on developing fuel-efficient aircraft

    SciTech Connect

    Not Available

    1989-06-01

    The USSR's research and design resources for aircraft propulsion development are concentrated in Moscow's Central Institute for Aviation Motors; design bureaus concerned with specific design tasks have limited research staffs, and are accordingly dependent on this institute for fundamental studies and test support. Full-scale test rigs are located at a facility outside Moscow; aircraft engines of all sizes can be run there at simulated flight speeds. The state-of-the-art turbofan engine that has been developed by this system is the Soloviev D-90, a 35,000-lb thrust class engine powering the Tu-204 and Il-96-300 transport aircraft currently undergoing testing; a specific fuel consumption level of 0.58 at Mach 0.8/36,000 ft altitude has been achieved.

  16. 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.

  17. Jet Stream Analysis and Forecast Errors Using GADS Aircraft Observations in the DAO, ECMWF, and NCEP Models

    NASA Technical Reports Server (NTRS)

    Cardinali, Carla; Rukhovets, Leonid; Tenenbaum, Joel

    2003-01-01

    We have utilized an extensive set of independent British Airways flight data recording wind vector and temperature observations (the Global Aircraft Data Set [GADS] archive) in three ways: (a) as an independent check of operational analyses; (b) as an analysis observing system experiment (OSE) as if the GADS observations were available in real time; and (c) as the corresponding forecast simulation experiment applicable to future operational forecasts. Using a 31 day sample (0000 UTC 20 December 2000 through 0000 UTC 20 January 2000) from Winter 2000, we conclude that over the data-dense continental U. S. analyzed jet streaks are too weak by -2% to -5%. Over nearby data-sparse regions of Canada, analyzed jet streaks are too weak by -5% to -9%. The second range provides a limit on the accuracy of current jet streak analyses over the portions of the -85% of the earth's surface that are poorly covered by non-satellite observations. The -5% to -9% range is relevant for the pre-third generation satellite (AIRS, IASI, GIFTS) era.

  18. 76 FR 19903 - Special Conditions: Diamond Aircraft Industry Model DA-40NG; Diesel Cycle Engine

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-11

    ...These special conditions are issued for the Diamond Aircraft Industry (DAI) GmbH model DA-40NG the Austro Engine GmbH model E4 aircraft diesel engine (ADE) using turbine (jet) fuel. This airplane will have a novel or unusual design feature(s) associated with the installation of a diesel cycle engine utilizing turbine (jet) fuel. The applicable airworthiness regulations do not contain adequate......

  19. 76 FR 35912 - Business Jet Aircraft Industry: Structure and Factors Affecting Competitiveness; Institution of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-20

    ..., and business innovation; 4. Information on government policies and programs that focus on or otherwise involve the industry, including policies and programs affecting financing, aircraft research and... From the Federal Register Online via the Government Publishing Office INTERNATIONAL...

  20. FIELD-PRODUCED JP-8 STANDARD FOR CALIBRATION OF LOWER EXPLOSIVE LIMIT METERS USED BY JET FUEL TANK MAINTENANCE PERSONNEL

    EPA Science Inventory

    Thousands of military personnel and tens of thousands of civilian workers perform jet fuel tank entry procedures. Before entering the confined space of a jet fuel tank, OSHA regulations (29CFR1910.146) require the internal atmosphere be tested with a calibrated, direct-reading...

  1. A new approach for bio-jet fuel generation from palm oil and limonene in the absence of hydrogen.

    PubMed

    Zhang, Jingjing; Zhao, Chen

    2015-12-18

    The traditional methodology includes a carbon-chain shortening strategy to produce bio-jet fuel from lipids via a two-stage process with hydrogen. Here, we propose a new solution using a carbon-chain filling strategy to convert C10 terpene and lipids to jet fuel ranged hydrocarbons with aromatic hydrocarbon ingredients in the absence of hydrogen.

  2. Concepts for reducing exhaust emissions and fuel consumption of the aircraft piston engine

    NASA Technical Reports Server (NTRS)

    Rezy, B. J.; Stuckas, K. J.; Tucker, J. R.; Meyers, J. E.

    1979-01-01

    A study was made to reduce exhaust emissions and fuel consumption of a general aviation aircraft piston engine by applying known technology. Fourteen promising concepts such as stratified charge combustion chambers, cooling cylinder head improvements, and ignition system changes were evaluated for emission reduction and cost effectiveness. A combination of three concepts, improved fuel injection system, improved cylinder head with exhaust port liners and exhaust air injection was projected as the most cost effective and safe means of meeting the EPA standards for CO, HC and NO. The fuel economy improvement of 4.6% over a typical single engine aircraft flight profile does not though justify the added cost of the three concepts, and significant reductions in fuel consumption must be applied to the cruise mode where most of the fuel is used. The use of exhaust air injection in combination with exhaust port liners reduces exhaust valve stem temperatures which can result in longer valve guide life. The use of exhaust port liners alone can reduce engine cooling air requirements by 11% which is the equivalent of a 1.5% increase in propulsive power. The EPA standards for CO, HC and NO can be met in the IO-520 engine using air injection alone or the Simmonds improved fuel injection system.

  3. 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.

  4. Carbon-13 and proton nuclear magnetic resonance analysis of shale-derived refinery products and jet fuels and of experimental referee broadened-specification jet fuels

    NASA Technical Reports Server (NTRS)

    Dalling, D. K.; Bailey, B. K.; Pugmire, R. J.

    1984-01-01

    A proton and carbon-13 nuclear magnetic resonance (NMR) study was conducted of Ashland shale oil refinery products, experimental referee broadened-specification jet fuels, and of related isoprenoid model compounds. Supercritical fluid chromatography techniques using carbon dioxide were developed on a preparative scale, so that samples could be quantitatively separated into saturates and aromatic fractions for study by NMR. An optimized average parameter treatment was developed, and the NMR results were analyzed in terms of the resulting average parameters; formulation of model mixtures was demonstrated. Application of novel spectroscopic techniques to fuel samples was investigated.

  5. Propulsion. [NASA program for aircraft fuel consumption reduction

    NASA Technical Reports Server (NTRS)

    Nored, D. L.

    1978-01-01

    NASA aims at developing propulsion technology to reduce the fuel consumption of present engines by 5%, that of new engines of the late 1980s by at least 12%, and that of an advanced early 1990s turboprop by an additional 15%. This paper reviews three separate NASA programs which take up these aims. They are, respectively, Engine Component Improvement, Energy Efficient Engine, and Advanced Turboprops.

  6. Design of "model-friendly" turbulent non-premixed jet burners for C2+ hydrocarbon fuels

    NASA Astrophysics Data System (ADS)

    Zhang, Jiayao; Shaddix, Christopher R.; Schefer, Robert W.

    2011-07-01

    Experimental measurements in laboratory-scale turbulent burners with well-controlled boundary and flow configurations can provide valuable data for validating models of turbulence-chemistry interactions applicable to the design and analysis of practical combustors. This paper reports on the design of two canonical nonpremixed turbulent jet burners for use with undiluted gaseous and liquid hydrocarbon fuels, respectively. Previous burners of this type have only been developed for fuels composed of H2, CO, and/or methane, often with substantial dilution. While both new burners are composed of concentric tubes with annular pilot flames, the liquid-fuel burner has an additional fuel vaporization step and an electrically heated fuel vapor delivery system. The performance of these burners is demonstrated by interrogating four ethylene flames and one flame fueled by a simple JP-8 surrogate. Through visual observation, it is found that the visible flame lengths show good agreement with standard empirical correlations. Rayleigh line imaging demonstrates that the pilot flame provides a spatially homogeneous flow of hot products along the edge of the fuel jet. Planar imaging of OH laser-induced fluorescence reveals a lack of local flame extinction in the high-strain near-burner region for fuel jet Reynolds numbers (Re) less than 20 000, and increasingly common extinction events for higher jet velocities. Planar imaging of soot laser-induced incandescence shows that the soot layers in these flames are relatively thin and are entrained into vortical flow structures in fuel-rich regions inside of the flame sheet.

  7. Liquid phase products and solid deposit formation from thermally stressed model jet fuels

    NASA Technical Reports Server (NTRS)

    Kim, W. S.; Bittker, D. A.

    1984-01-01

    The relationship between solid deposit formation and liquid degradation product concentration was studied for the high temperature (400 C) stressing of three hydrocarbon model fuels. A Jet Fuel Thermal Oxidation Tester was used to simulate actual engine fuel system conditions. The effects of fuel type, dissolved oxygen concentration, and hot surface contact time (reaction time) were studied. Effects of reaction time and removal of dissolved oxygen on deposit formation were found to be different for n-dodecane and for 2-ethylnaphthalene. When ten percent tetralin is added to n-dodecane to give a simpler model of an actual jet fuel, the tetralin inhibits both the deposit formation and the degradation of n-dodecane. For 2-ethylnaphthalene primary product analyses indicate a possible self-inhibition at long reaction times of the secondary reactions which form the deposit precursors. The mechanism of the primary breakdown of these fuels is suggested and the primary products which participate in these precursor-forming reactions are identified. Some implications of the results to the thermal degradation of real jet fuels are given.

  8. Possible use of polyaphronated hydrocarbons at jet fuels

    SciTech Connect

    Sebba, F.; Schetz, J.A. ); Neff, R.B. )

    1987-04-01

    The Air Force is interested in low cost missile propulsion systems which meet the need for increased stand off range and can fly at high speeds at both low and high altitudes. Due to their high performance capabilities, liquid fueled ramjets are important candidates for these missions. They tend to perform well when the combustor length is long enough to enable all of the fuel to be burned before being lost through the exhaust nozzle. When a combustor has to be shortened due to size limitations, liquid fuel performance drops as a result of not burning all of the injected fuel. Proper fuel injection and atomization are essential factors in obtaining high performance in all liquid fueled ramjets and other air breathing combustion systems. Poor fuel atomization results in low combustion efficiency, contributes to combustion instability, and aids in the formation of pollutants. Very fine fuel atomization requires complex fuel control injection systems which are impractical for ramjet applications. The recent developments in the colloid system, polyaphrons, opens up the possibility that fuels prepared in this way may increase the performance of ramjet propulsion systems, particularly those which are limited in combustion efficiency due to short evaporation and residence times, such as is the case for the very compact swirl combustor configurations. Polyaphrons have the potential to induce better atomization thereby decreasing residence times required for individual droplet burning.

  9. Jet fuel ignition delay times: Shock tube experiments over wide conditions and surrogate model predictions

    SciTech Connect

    Vasu, Subith S.; Davidson, David F.; Hanson, Ronald K.

    2008-01-15

    Ignition delay times were measured for gas-phase jet fuel (Jet-A and JP-8) in air behind reflected shock waves in a heated high-pressure shock tube. Initial reflected shock conditions were as follows: temperatures of 715-1229 K, pressures of 17-51 atm, equivalence ratios of 0.5 and 1, and oxygen concentrations of 10 and 21% in synthetic air. Ignition delay times were measured using sidewall pressure and OH* emission at 306 nm. Longer ignition delay times at low temperatures (715-850 K) were accessed by utilizing driver-gas tailoring methods. Also presented is a review of previous ignition delay time measurements of kerosene-based fuels and recent work on surrogate fuel and kinetic mechanism development. To our knowledge, we report the first gas-phase shock tube ignition delay time data for JP-8, and our measurements for Jet-A are for a broader range of conditions than previously available. Our results have very low scatter and are in excellent agreement with the limited previous shock tube data for Jet-A. Although JP-8 and Jet-A have slightly different compositions, their ignition delay times are very similar. A simple 1/P dependence was found for ignition delay times from 874 to 1220 K for the pressure range studied for both fuels. Ignition delay time variations with equivalence ratio and oxygen concentration were also investigated. The new experimental results were compared with predictions of several kinetic mechanisms, using different jet fuel surrogate mixtures. (author)

  10. 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.

  11. BIOGEOCHEMICAL EVIDENCE FOR MICROBIAL COMMUNITY CHANGE IN A JET FUEL HYDROCARBONS-CONTAMINATED AQUIFER

    EPA Science Inventory

    A glacio-fluvial aquifer located at Wurtsmith Air Force Base, Michigan, had been contaminated with JP-4 fuel hydrocarbons released after the crash of a tanker aircraft in October of 1988 Microbial biomass and community structure, associated with the aquifer sediments, were chara...

  12. An experimental study of the autoignition characteristics of conventional jet fuel/oxidizer mixtures: Jet-A and JP-8

    SciTech Connect

    Kumar, Kamal; Sung, Chih-Jen

    2010-04-15

    Ignition delay times of Jet-A/oxidizer and JP-8/oxidizer mixtures are measured using a heated rapid compression machine at compressed charge pressures corresponding to 7, 15, and 30 bar, compressed temperatures ranging from 650 to 1100 K, and equivalence ratios varying from 0.42 to 2.26. When using air as the oxidant, two oxidizer-to-fuel mass ratios of 13 and 19 are investigated. To achieve higher compressed temperatures for fuel lean mixtures (equivalence ratio of {proportional_to}0.42), argon dilution is also used and the corresponding oxidizer-to-fuel mass ratio is 84.9. For the conditions studied, experimental results show two-stage ignition characteristics for both Jet-A and JP-8. Variations of both the first-stage and overall ignition delays with compressed temperature, compressed pressure, and equivalence ratio are reported and correlated. It is noted that the negative temperature coefficient phenomenon becomes more prominent at relatively lower pressures. Furthermore, the first-stage-ignition delay is found to be less sensitive to changes in equivalence ratio and primarily dependent on temperature. (author)

  13. Evaluation of plasma jet ignition for improved performance of alternate fuels

    NASA Astrophysics Data System (ADS)

    Grant, J. F.; Golenko, Z.; McIlwain, M. E.

    1982-08-01

    Alcohols, such as ethanol and methanol, are potential substitutes for gasolines during periods of fuel shortages. The pure alcohols have been reported to cause performance and starting problems when used to fuel internal combustion engines. This study characterized how three modes of ignition, OEM magneto, high energy conventional spark (CI) and plasma jet ignition (PJI) influenced the engine combustion properties of ethanol, methanol and gasoline alcohol blends. Specific combustion properties examined in these measurement were burning velocity and lean limit. In addition, the engine performance was determined for 30% alcohol gasoline containing blends. These engine performance measurements determined brake power, brake specific fuel consumption and brake emissions of carbon monoxide and hydrocarbons. The findings of this study suggest that high energy ignition systems, such as plasma jet ignition, will improve both fuel combustion properties and engine performance.

  14. Flame ignition studies of conventional and alternative jet fuels and surrogate components

    NASA Astrophysics Data System (ADS)

    Liu, Ning

    Practical jet fuels are widely used in air-breathing propulsion, but the chemical mechanisms that control their combustion are not yet understood. Thousands of components are contained in conventional and alternative jet fuels, making thus any effort to model their combustion behavior a daunting task. That has been the motivation behind the development of surrogate fuels that contain typically a small number of neat components, whose physical properties and combustion behavior mimic those of the real jet fuel, and whose kinetics could be modeled with increased degree of confidence. Towards that end, a large number of experimental data are required both for the real fuels and the attendant surrogate components that could be used to develop and validate detailed kinetic models. Those kinetic models could be used then upon reduction to model a combustor and eventually optimize its performance. Among all flame phenomena, ignition is rather sensitive to the oxidative and pyrolytic propensity of the fuel as well as to its diffusivity. The counterflow configuration is ideal in probing both the fuel reactivity and diffusivity aspects of the ignition process and it was used in the present work to determine the ignition temperatures of premixed and non-premixed flames of a variety of fuels relevant to air-breathing propulsion. The experiments were performed at atmospheric pressure, elevated unburned fuel mixture temperatures, and various strain rates that were measured locally. Several recent kinetic models were used in direct numerical simulations of the experiments and the computed results were tested against the experimental data. Furthermore, through sensitivity, reaction path, and structure analyses of the computed flames, insight was provided into the dominant mechanisms that control ignition. It was found that ignition is primarily sensitive to fuel diffusion and secondarily sensitive to chemical kinetics and intermediate species diffusivities under the low fuel

  15. Thermal oxidative stability of coal-based JP-900 jet fuel: Impact on selected physical properties

    NASA Astrophysics Data System (ADS)

    Berkhous, Scott K.

    The low-temperature oxidative stability of a fuel is determined by the potential for production of peroxides, leading to the formation of oxygenated products, change in color, and ultimately formation of sediment. The role of oxygenated products in determining the low-temperature physical properties of jet fuels has not been reported in the literature. The current study evaluates the impact of oxidative jet fuel stability on the following low-temperature properties: crystal size, crystal shape, freeze point, and viscosity. It was found that over the range of oxidative conditions studied, compositionally similar products were produced for each fuel. Increasing the reaction temperature, between 50°C and 200°C, and pressure, between atmospheric and 200 psi, altered the quantity of oxidation products, but did not significantly shift the composition of these products. Major products observed in the oxidation of jet fuel samples included alcohols, ketones, and to a lesser extent acids. The predominant crystal structures observed using cold-stage microscope techniques were small needle-like structures for cycloalkane-based fuels and large broad leaf-shaped structures for n-alkane-based fuels. The presence of oxidized compounds in the fuel samples decreased the overall size of the crystals and produced ribbon-shaped crystals in the n -alkane-based fuels. This was the result of the oxygenated functionalities of the polar compounds interrupting the regular alignment of molecules in the crystal structure. Major differences in the freeze points of oxidized and unoxidized fuel samples were not observed. However, the viscosities of the oxidized fuel samples were found to be higher at all temperatures than the unoxidized fuel samples. The model of Coutinho et al. was found to be effective for predicting the freeze point of n-alkane-rich fuels, but failed to accurately predict the freeze point of cycloalkane-based hydrocarbons. A model by Cookson et al. was found to be effective

  16. An evaluation of NASA's program for improving aircraft fuel efficiency

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The report provides commentary and recommendations where appropriate on each of the major elements of the program. Key findings of the committee included a recommendation that closer ties be established between NASA and the FAA to expedite the use and acceptance of the new technology. The committee also cited the potential for fuel savings through an imporved air traffic control system and recommended that the management of NASA and the FAA discuss ways and means to work together to exploit more effectively the capabilities and responsibilities of each to develop air traffic control.

  17. Life-cycle analysis of camelina biodiesel and jet-fuel

    NASA Astrophysics Data System (ADS)

    Dangol, Namrata

    Camelina sativa (Camelina) could be a potential feedstock to help meet the goal of 36 billion gallons of biofuel production in the United States by 2022, as set forth by EISA of 2007. This research is focused on assessing the energy balance and greenhouse gas (GHG) emissions from camelina biodiesel grown and produced in the Pacific Northwest (PNW) region of the USA. Data were collected from a camelina farm in the region and compared to literature values. Energy used in camelina crushing and transesterification were measured at the University of Idaho. Life cycle analysis showed that use of camelina biodiesel reduces GHG emissions by 72% compared to 2005 baseline diesel fuel. Camelina biodiesel at B100 level, however, did not meet the ASTM D6751 specification for oxidative stability without any additives but could be corrected with proper additive. Camelina had a smaller seed size compared to canola and consequently required 23% more energy for crushing. Despite higher energy use for crushing, the net energy ratio for camelina biodiesel was found to be 3.68. From the agronomic standpoint, camelina can be incorporated as a rotational crop into low rainfall areas of the PNW. Wheat areas of PNW with annual rainfall from 19 to 38 cm (7.5--15") and currently incorporating fallow into their rotations were considered as potential areas for camelina. There were 846,500 hectares (2.1 million acres) of land available in the region that could potentially produce 443.0 million L of biodiesel (117.1 million gal) and 1.2 billion kg of meal per year. This meal quantity is about 12.1% of the potential camelina meal that could be used as livestock feed in the PNW. Therefore, it was concluded that the meal has adequate market to be consumed locally as livestock feed. This research also conducted the life cycle analysis of camelina jet fuel produced in the laboratory scale facility. The jet fuel was produced via deoxygenation of the camelina oil in an inert environment, in the

  18. Advanced thermally stable jet fuels. Technical progress report, July 1995--September 1995

    SciTech Connect

    Schobert, H.H.; Eser, S.; Song, C.

    1995-10-01

    The Penn State program in advanced thermally stable jet engine fuels has five components: development of mechanisms of degradation and solids formation; quantitative measurement of growth of sub-micrometer-sized and micrometer particles suspended in fuels during thermal stresses; characterization of carbonaceous deposits by various instrumental and microscopic methods; elucidation of the role of additives in retarding the formation of carbonaceous solids; and assessment of the potential of producing high yields of cycloalkanes and hydroaromatics by direct coal liquefaction. Progress is described.

  19. Measurement of dose equivalent distribution on-board commercial jet aircraft.

    PubMed

    Kubančák, J; Ambrožová, I; Ploc, O; Pachnerová Brabcová, K; Štěpán, V; Uchihori, Y

    2014-12-01

    The annual effective doses of aircrew members often exceed the limit of 1 mSv for the public due to the increased level of cosmic radiation at the flight altitudes, and thus, it is recommended to monitor them [International Commission on Radiation Protection. 1990 Recommendations of the International Commission on Radiological Protection. ICRP Publication 60. Ann. ICRP 21: (1-3), (1991)]. According to the Monte Carlo simulations [Battistoni, G., Ferrari, A., Pelliccioni, M. and Villari, R. Evaluation of the doses to aircrew members taking into consideration the aircraft structures. Adv. Space Res. 36: , 1645-1652 (2005) and Ferrari, A., Pelliccioni, M. and Villari, R. Evaluation of the influence of aircraft shielding on the aircrew exposure through an aircraft mathematical model. Radiat. Prot. Dosim. 108: (2), 91-105 (2004)], the ambient dose equivalent rate Ḣ*(10) depends on the location in the aircraft. The aim of this article is to experimentally evaluate Ḣ*(10) on-board selected types of aircraft. The authors found that Ḣ*(10) values are higher in the front and the back of the cabin and lesser in the middle of the cabin. Moreover, total dosimetry characteristics obtained in this way are in a reasonable agreement with other data, in particular with the above-mentioned simulations. PMID:24344348

  20. Measurement of dose equivalent distribution on-board commercial jet aircraft.

    PubMed

    Kubančák, J; Ambrožová, I; Ploc, O; Pachnerová Brabcová, K; Štěpán, V; Uchihori, Y

    2014-12-01

    The annual effective doses of aircrew members often exceed the limit of 1 mSv for the public due to the increased level of cosmic radiation at the flight altitudes, and thus, it is recommended to monitor them [International Commission on Radiation Protection. 1990 Recommendations of the International Commission on Radiological Protection. ICRP Publication 60. Ann. ICRP 21: (1-3), (1991)]. According to the Monte Carlo simulations [Battistoni, G., Ferrari, A., Pelliccioni, M. and Villari, R. Evaluation of the doses to aircrew members taking into consideration the aircraft structures. Adv. Space Res. 36: , 1645-1652 (2005) and Ferrari, A., Pelliccioni, M. and Villari, R. Evaluation of the influence of aircraft shielding on the aircrew exposure through an aircraft mathematical model. Radiat. Prot. Dosim. 108: (2), 91-105 (2004)], the ambient dose equivalent rate Ḣ*(10) depends on the location in the aircraft. The aim of this article is to experimentally evaluate Ḣ*(10) on-board selected types of aircraft. The authors found that Ḣ*(10) values are higher in the front and the back of the cabin and lesser in the middle of the cabin. Moreover, total dosimetry characteristics obtained in this way are in a reasonable agreement with other data, in particular with the above-mentioned simulations.

  1. 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.

  2. Climate Impact and Economic Feasibility of Solar Thermochemical Jet Fuel Production.

    PubMed

    Falter, Christoph; Batteiger, Valentin; Sizmann, Andreas

    2016-01-01

    Solar thermochemistry presents a promising option for the efficient conversion of H2O and CO2 into liquid hydrocarbon fuels using concentrated solar energy. To explore the potential of this fuel production pathway, the climate impact and economic performance are analyzed. Key drivers for the economic and ecological performance are thermochemical energy conversion efficiency, the level of solar irradiation, operation and maintenance, and the initial investment in the fuel production plant. For the baseline case of a solar tower concentrator with CO2 capture from air, jet fuel production costs of 2.23 €/L and life cycle greenhouse gas (LC GHG) emissions of 0.49 kgCO2-equiv/L are estimated. Capturing CO2 from a natural gas combined cycle power plant instead of the air reduces the production costs by 15% but leads to LC GHG emissions higher than that of conventional jet fuel. Favorable assumptions for all involved process steps (30% thermochemical energy conversion efficiency, 3000 kWh/(m(2) a) solar irradiation, low CO2 and heliostat costs) result in jet fuel production costs of 1.28 €/L at LC GHG emissions close to zero. Even lower production costs may be achieved if the commercial value of oxygen as a byproduct is considered. PMID:26641878

  3. Climate Impact and Economic Feasibility of Solar Thermochemical Jet Fuel Production.

    PubMed

    Falter, Christoph; Batteiger, Valentin; Sizmann, Andreas

    2016-01-01

    Solar thermochemistry presents a promising option for the efficient conversion of H2O and CO2 into liquid hydrocarbon fuels using concentrated solar energy. To explore the potential of this fuel production pathway, the climate impact and economic performance are analyzed. Key drivers for the economic and ecological performance are thermochemical energy conversion efficiency, the level of solar irradiation, operation and maintenance, and the initial investment in the fuel production plant. For the baseline case of a solar tower concentrator with CO2 capture from air, jet fuel production costs of 2.23 €/L and life cycle greenhouse gas (LC GHG) emissions of 0.49 kgCO2-equiv/L are estimated. Capturing CO2 from a natural gas combined cycle power plant instead of the air reduces the production costs by 15% but leads to LC GHG emissions higher than that of conventional jet fuel. Favorable assumptions for all involved process steps (30% thermochemical energy conversion efficiency, 3000 kWh/(m(2) a) solar irradiation, low CO2 and heliostat costs) result in jet fuel production costs of 1.28 €/L at LC GHG emissions close to zero. Even lower production costs may be achieved if the commercial value of oxygen as a byproduct is considered.

  4. Biomass-derived Lignin to Jet Fuel Range Hydrocarbons via Aqueous Phase Hydrodeoxygenation

    SciTech Connect

    Wang, Hongliang; Ruan, Hao; Pei, Haisheng; Wang, Huamin; Chen, Xiaowen; Tucker, Melvin P.; Cort, John R.; Yang, Bin

    2015-09-14

    A catalytic process, involving the hydrodeoxygenation (HDO) of the dilute alkali extracted corn stover lignin catalysed by noble metal catalyst (Ru/Al2O3) and acidic zeolite (H+-Y), to produce lignin-substructure-based hydrocarbons (C7-C18), primarily C12-C18 cyclic structure hydrocarbons in the jet fuel range, was demonstrated.

  5. Photocatalytical oxidation of de-icing agents in aqueous solutions and aqueous extract of jet fuel.

    PubMed

    Krichevskaya, M; Malygina, T; Preis, S; Kallas, J

    2001-01-01

    Improper handling of jet fuel at abandoned military bases has resulted in heavy pollution of the soil and groundwater. Experimental research of photocatalytical oxidation (PCO) of jet fuel aqueous extract and aqueous solutions of de-icing agents was undertaken. The influence of different parameters - pH, concentration of substances to be oxidised, presence of inorganic admixtures, effect of OH. radical generators--on the PCO of solutions of de-icing agents and jet fuel aqueous extract was determined. The role of OH. radicals was found to be less important in determining the PCO rate. The PCO of organic pollutants was also investigated using a catalyst immobilised onto the surface of buoyant hollow glass microspheres. Attached titanium dioxide (TiO2) showed lower photocatalytical activity than when suspended in slurry, although it allows waters to be treated in simple shallow ponds without intensive stirring. The biodegradability of aqueous solutions of de-icing agents and jet fuel aqueous extract increased as PCO proceeded. PMID:11695445

  6. Combustion Gas Properties I-ASTM Jet a Fuel and Dry Air

    NASA Technical Reports Server (NTRS)

    Jones, R. E.; Trout, A. M.; Wear, J. D.; Mcbride, B. J.

    1984-01-01

    A series of computations was made to produce the equilibrium temperature and gas composition for ASTM jet A fuel and dry air. The computed tables and figures provide combustion gas property data for pressures from 0.5 to 50 atmospheres and equivalence ratios from 0 to 2.0.

  7. METHOD OF LIQUID-LIQUID EXTRACTION OF BLOOD SURROGATES FOR ASSESSING HUMAN EXPOSURE TO JET FUEL

    EPA Science Inventory

    A baseline method of liquid?liquid extraction for assessing human exposure to JP-8 jet fuel was established by extracting several representative compounds ranging from very volatile to semi-volatile organic compounds, including benzene, toluene, nonane, decane, undecane, tridec...

  8. The Utility of Naphthyl-Keratin Adducts as Biomarkers for Jet-Fuel Exposure

    EPA Science Inventory

    We investigated the association between biomarkers of dermal exposure, naphthyl-keratin adducts (NKA), and urine naphthalene biomarker levels in 105 workers routinely exposed to jet-fuel. A moderate correlation was observed between NKA and urine naphthalene levels (p = 0.061). Th...

  9. EXHALED HUMAN BREATH MEASUREMENT OF JET FUEL CONSTITUENTS: DISTINGUISHING BETWEEN INHALATION AND DERMAL EXPOSURE ROUTES

    EPA Science Inventory

    In response to anecdotal reports, perceived health issues, and widespread complaints, the U.S. military launched an investigation into the occupational and environmental human exposure to jet fuel. The work described in the presentation assesses the correlation between two breat...

  10. Analyzing hydrotreated renewable jet fuel (HRJ) feedstock availability using crop simulation modeling

    Technology Transfer Automated Retrieval System (TEKTRAN)

    While hydrotreated renewable jet fuel (HRJ) has been demonstrated for use in commercial and military aviation, a challenge to large-scale adoption is availability of cost competitive feedstocks. Brassica oilseed crops like Brassica napus, B. rapa, B. juncea, B. carinata, Sinapis alba, and Camelina s...

  11. Spatial distribution of jet fuel in the vadoze zone of a heterogeneous and fractured soil.

    PubMed

    Tzovolou, D N; Benoit, Y; Haeseler, F; Klint, K E; Tsakiroglou, C D

    2009-04-01

    The goal of the present work is to screen and evaluate all available data before selecting and testing remediation technologies on heterogeneous soils polluted by jet fuel. The migration pathways of non-aqueous phase liquids (NAPLs) in the subsurface relate closely with soil properties. A case study is performed on the vadoze zone of a military airport of north-west Poland contaminated by jet fuel. Soil samples are collected from various depths of two cells, and on-site and off-site chemical analyses of hydrocarbons are conducted by using Pollut Eval apparatus and GC-MS, respectively. The geological conceptual model of the site along with microscopic and hydraulic properties of the porous matrix and fractures enable us to interpret the non-uniform spatial distribution of jet fuel constituents. The total concentration of the jet fuel and its main hydrocarbon families (n-paraffins, major aromatics) over the two cells is governed by the slow preferential flow of NAPL through the porous matrix, the rapid NAPL convective flow through vertical desiccation and sub-horizontal glaciotectonic fractures, and n-paraffin biodegradation in upper layers where the rates of oxygen transfer is not limited by complexities of the pore structure. The information collected is valuable for the selection, implementation and evaluation of two in situ remediation methods.

  12. Effects of three activities on annoyance responses to recorded flyovers. [human tolerance of jet aircraft noise

    NASA Technical Reports Server (NTRS)

    Gunn, W. J.; Shepherd, W. T.; Fletcher, J. L.

    1975-01-01

    Human subjects participated in an experiment in which they were engaged in TV viewing, telephone listening, or reverie (no activity) for a 1/2-hour session. During the session, they were exposed to a series of recorded aircraft sounds at the rate of one flight every 2 minutes. At each session, four levels of flyover noise, separated by 5 db increments were presented several times in a Latin Square balanced sequence. The peak levels of the noisiest flyover in any session was fixed at 95, 90, 85, 75, or 70 db. At the end of the test session, subjects recorded their responses to the aircraft sounds, using a bipolar scale which covered the range from very pleasant to extremely annoying. Responses to aircraft noises are found to be significantly affected by the particular activity in which the subjects are engaged.

  13. Effect of fuel properties on performance of a single aircraft turbojet combustor

    NASA Technical Reports Server (NTRS)

    Butze, H. F.; Ehlers, R. C.

    1975-01-01

    The performance of a single-can JT8D combustor was investigated with a number of fuels exhibiting wide variations in chemical composition and volatility. Performance parameters investigated were combustion efficiency, emissions of CO, unburned hydrocarbons and NOx, as well as liner temperatures and smoke. At the simulated idle condition no significant differences in performance were observed. At cruise, liner temperatures and smoke increased sharply with decreasing hydrogen content of the fuel. No significant differences were observed in the performance of an oil-shale derived JP-5 and a petroleum-based Jet A fuel except for emissions of NOx which were higher with the oil-shale JP-5. The difference is attributed to the higher concentration of fuel-bound nitrogen in the oil-shale JP-5.

  14. Life-Cycle Analysis of Alternative Aviation Fuels in GREET

    SciTech Connect

    Elgowainy, A.; Han, J.; Wang, M.; Carter, N.; Stratton, R.; Hileman, J.; Malwitz, A.; Balasubramanian, S.

    2012-06-01

    The Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET) model, developed at Argonne National Laboratory, has been expanded to include well-to-wake (WTWa) analysis of aviation fuels and aircraft. This report documents the key WTWa stages and assumptions for fuels that represent alternatives to petroleum jet fuel. The aviation module in GREET consists of three spreadsheets that present detailed characterizations of well-to-pump and pump-to-wake parameters and WTWa results. By using the expanded GREET version (GREET1_2011), we estimate WTWa results for energy use (total, fossil, and petroleum energy) and greenhouse gas (GHG) emissions (carbon dioxide, methane, and nitrous oxide) for (1) each unit of energy (lower heating value) consumed by the aircraft or(2) each unit of distance traveled/ payload carried by the aircraft. The fuel pathways considered in this analysis include petroleum-based jet fuel from conventional and unconventional sources (i.e., oil sands); Fisher-Tropsch (FT) jet fuel from natural gas, coal, and biomass; bio-jet fuel from fast pyrolysis of cellulosic biomass; and bio-jet fuel from vegetable and algal oils, which falls under the American Society for Testing and Materials category of hydroprocessed esters and fatty acids. For aircraft operation, we considered six passenger aircraft classes and four freight aircraft classes in this analysis. Our analysis revealed that, depending on the feedstock source, the fuel conversion technology, and the allocation or displacement credit methodology applied to co-products, alternative bio-jet fuel pathways have the potential to reduce life-cycle GHG emissions by 55–85 percent compared with conventional (petroleum-based) jet fuel. Although producing FT jet fuel from fossil feedstock sources — such as natural gas and coal — could greatly reduce dependence on crude oil, production from such sources (especially coal) produces greater WTWa GHG emissions compared with petroleum jet

  15. Life-cycle analysis of alternative aviation fuels in GREET

    SciTech Connect

    Elgowainy, A.; Han, J.; Wang, M.; Carter, N.; Stratton, R.; Hileman, J.; Malwitz, A.; Balasubramanian, S.

    2012-07-23

    The Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET) model, developed at Argonne National Laboratory, has been expanded to include well-to-wake (WTWa) analysis of aviation fuels and aircraft. This report documents the key WTWa stages and assumptions for fuels that represent alternatives to petroleum jet fuel. The aviation module in GREET consists of three spreadsheets that present detailed characterizations of well-to-pump and pump-to-wake parameters and WTWa results. By using the expanded GREET version (GREET1{_}2011), we estimate WTWa results for energy use (total, fossil, and petroleum energy) and greenhouse gas (GHG) emissions (carbon dioxide, methane, and nitrous oxide) for (1) each unit of energy (lower heating value) consumed by the aircraft or (2) each unit of distance traveled/ payload carried by the aircraft. The fuel pathways considered in this analysis include petroleum-based jet fuel from conventional and unconventional sources (i.e., oil sands); Fisher-Tropsch (FT) jet fuel from natural gas, coal, and biomass; bio-jet fuel from fast pyrolysis of cellulosic biomass; and bio-jet fuel from vegetable and algal oils, which falls under the American Society for Testing and Materials category of hydroprocessed esters and fatty acids. For aircraft operation, we considered six passenger aircraft classes and four freight aircraft classes in this analysis. Our analysis revealed that, depending on the feedstock source, the fuel conversion technology, and the allocation or displacement credit methodology applied to co-products, alternative bio-jet fuel pathways have the potential to reduce life-cycle GHG emissions by 55-85 percent compared with conventional (petroleum-based) jet fuel. Although producing FT jet fuel from fossil feedstock sources - such as natural gas and coal - could greatly reduce dependence on crude oil, production from such sources (especially coal) produces greater WTWa GHG emissions compared with petroleum jet

  16. From animal cage to aircraft cabin: an overview of evidence translation in jet lag research.

    PubMed

    Atkinson, Greg; Batterham, Alan M; Dowdall, Nigel; Thompson, Andrew; van Drongelen, Alwin

    2014-12-01

    Recent laboratory experiments on rodents have increased our understanding of circadian rhythm mechanisms. Typically, circadian biologists attempt to translate their laboratory-based findings to treatment of jet lag symptoms in humans. We aimed to scrutinise the strength of the various links in the translational pathway from animal model to human traveller. First, we argue that the translation of findings from pre-clinical studies to effective jet lag treatments and knowledge regarding longer-term population health is not robust, e.g. the association between circadian disruption and cancer found in animal models does not translate well to cabin crew and pilots, who have a lower risk of most cancers. Jet lag symptoms are heterogeneous, making the true prevalence and the effects of any intervention difficult to quantify precisely. The mechanistic chain between in vitro and in vivo treatment effects has weak links, especially between circadian rhythm disruption in animals and the improvement of jet lag symptoms in humans. While the number of animal studies has increased exponentially between 1990 and 2014, only 1-2 randomised controlled trials on jet lag treatments are published every year. There is one relevant Cochrane review, in which only 2-4 studies on melatonin, without baseline measures, were meta-analysed. Study effect sizes reduced substantially between 1987, when the first paper on melatonin was published, and 2000. We suggest that knowledge derived from a greater number of human randomised controlled trials would provide a firmer platform for circadian biologists to cite jet lag treatment as an important application of their findings. PMID:25342081

  17. From animal cage to aircraft cabin: an overview of evidence translation in jet lag research.

    PubMed

    Atkinson, Greg; Batterham, Alan M; Dowdall, Nigel; Thompson, Andrew; van Drongelen, Alwin

    2014-12-01

    Recent laboratory experiments on rodents have increased our understanding of circadian rhythm mechanisms. Typically, circadian biologists attempt to translate their laboratory-based findings to treatment of jet lag symptoms in humans. We aimed to scrutinise the strength of the various links in the translational pathway from animal model to human traveller. First, we argue that the translation of findings from pre-clinical studies to effective jet lag treatments and knowledge regarding longer-term population health is not robust, e.g. the association between circadian disruption and cancer found in animal models does not translate well to cabin crew and pilots, who have a lower risk of most cancers. Jet lag symptoms are heterogeneous, making the true prevalence and the effects of any intervention difficult to quantify precisely. The mechanistic chain between in vitro and in vivo treatment effects has weak links, especially between circadian rhythm disruption in animals and the improvement of jet lag symptoms in humans. While the number of animal studies has increased exponentially between 1990 and 2014, only 1-2 randomised controlled trials on jet lag treatments are published every year. There is one relevant Cochrane review, in which only 2-4 studies on melatonin, without baseline measures, were meta-analysed. Study effect sizes reduced substantially between 1987, when the first paper on melatonin was published, and 2000. We suggest that knowledge derived from a greater number of human randomised controlled trials would provide a firmer platform for circadian biologists to cite jet lag treatment as an important application of their findings.

  18. Protozoa in subsurface sediments from sites contaminated with aviation gasoline or jet fuel

    SciTech Connect

    Sinclair, J.L.; Kampbell, D.H.; Cook, M.L.; Wilson, J.T.

    1993-01-01

    Numbers of protozoa in the subsurface of aviation gasoline and jet fuel spill areas at a Coast Guard base at Traverse City, Mich., were determined. Boreholes were drilled in an uncontaminated location, in contaminated but untreated parts of the fuel plumes, and in the aviation gasoline source area undergoing H2O2 biotreatment. Protozoa were found to occur in elevated numbers in the unsaturated zone, where fuel vapors mixed with atmospheric oxygen, and below the layer of floating fuel, where uncontaminated groundwater came into contact with fuel. Numbers of protozoa in some contaminated areas equalled or exceeded those found in surface soil. The abundance of protozoa in the biotreatment area was high enough that it would be expected to significantly reduce the bacterial community that was degrading the fuel.

  19. Near-field shock formation in noise propagation from a high-power jet aircraft.

    PubMed

    Gee, Kent L; Neilsen, Tracianne B; Downing, J Micah; James, Michael M; McKinley, Richard L; McKinley, Robert C; Wall, Alan T

    2013-02-01

    Noise measurements near the F-35A Joint Strike Fighter at military power are analyzed via spatial maps of overall and band pressure levels and skewness. Relative constancy of the pressure waveform skewness reveals that waveform asymmetry, characteristic of supersonic jets, is a source phenomenon originating farther upstream than the maximum overall level. Conversely, growth of the skewness of the time derivative with distance indicates that acoustic shocks largely form through the course of near-field propagation and are not generated explicitly by a source mechanism. These results potentially counter previous arguments that jet "crackle" is a source phenomenon.

  20. Near-field shock formation in noise propagation from a high-power jet aircraft.

    PubMed

    Gee, Kent L; Neilsen, Tracianne B; Downing, J Micah; James, Michael M; McKinley, Richard L; McKinley, Robert C; Wall, Alan T

    2013-02-01

    Noise measurements near the F-35A Joint Strike Fighter at military power are analyzed via spatial maps of overall and band pressure levels and skewness. Relative constancy of the pressure waveform skewness reveals that waveform asymmetry, characteristic of supersonic jets, is a source phenomenon originating farther upstream than the maximum overall level. Conversely, growth of the skewness of the time derivative with distance indicates that acoustic shocks largely form through the course of near-field propagation and are not generated explicitly by a source mechanism. These results potentially counter previous arguments that jet "crackle" is a source phenomenon. PMID:23363199

  1. Refinery Integration of By-Products from Coal-Derived Jet Fuels

    SciTech Connect

    Caroline Clifford; Andre Boehman; Chunshan Song; Bruce Miller; Gareth Mitchell

    2008-03-31

    The final report summarizes the accomplishments toward project goals during length of the project. The goal of this project was to integrate coal into a refinery in order to produce coal-based jet fuel, with the major goal to examine the products other than jet fuel. These products are in the gasoline, diesel and fuel oil range and result from coal-based jet fuel production from an Air Force funded program. The main goal of Task 1 was the production of coal-based jet fuel and other products that would need to be utilized in other fuels or for non-fuel sources, using known refining technology. The gasoline, diesel fuel, and fuel oil were tested in other aspects of the project. Light cycle oil (LCO) and refined chemical oil (RCO) were blended, hydrotreated to removed sulfur, and hydrogenated, then fractionated in the original production of jet fuel. Two main approaches, taken during the project period, varied where the fractionation took place, in order to preserve the life of catalysts used, which includes (1) fractionation of the hydrotreated blend to remove sulfur and nitrogen, followed by a hydrogenation step of the lighter fraction, and (2) fractionation of the LCO and RCO before any hydrotreatment. Task 2 involved assessment of the impact of refinery integration of JP-900 production on gasoline and diesel fuel. Fuel properties, ignition characteristics and engine combustion of model fuels and fuel samples from pilot-scale production runs were characterized. The model fuels used to represent the coal-based fuel streams were blended into full-boiling range fuels to simulate the mixing of fuel streams within the refinery to create potential 'finished' fuels. The representative compounds of the coal-based gasoline were cyclohexane and methyl cyclohexane, and for the coal-base diesel fuel they were fluorine and phenanthrene. Both the octane number (ON) of the coal-based gasoline and the cetane number (CN) of the coal-based diesel were low, relative to commercial

  2. 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

  3. Transport jet aircraft noise abatement in foreign countries: Growth, structure, impact. Volume 1: Europe, July 1980

    NASA Technical Reports Server (NTRS)

    Spencer, F. A.

    1980-01-01

    The development and implementation of aircraft noise control regulations in various European states are described. The countries include the United Kingdom, France, Switzerland, Federal Republic of Germany, Sweden, Denmark, and the Netherlands. Topics discussed include noise monitoring, airport curfews, land use planning, and the government structure for noise regulation.

  4. Jet aircraft engine emissions database development: 1992 military, charter, and nonscheduled traffic

    NASA Technical Reports Server (NTRS)

    Metwally, Munir

    1995-01-01

    Studies relating to environmental emissions database for the military, charter, and non-scheduled traffic for the year 1992 were conducted by McDonnell Douglas Aerospace Transport Aircraft. The report also includes a comparison with a previous emission database for year 1990. Discussions of the methodology used in formulating these databases are provided.

  5. Effects of Fuel Composition on Combustion Stability and NO X Emissions for Traditional and Alternative Jet Fuels

    NASA Astrophysics Data System (ADS)

    Vijlee, Shazib Z.

    Synthetic jet fuels are studied to help understand their viability as alternatives to traditionally derived jet fuel. Two combustion parameters -- flame stability and NOX emissions -- are used to compare these fuels through experiments and models. At its core, this is a fuels study comparing how chemical makeup and behavior relate. Six 'real', complex fuels are studied in this work -- four are synthetic from alternative sources and two are traditional from petroleum sources. Two of the synthetic fuels are derived from natural gas and coal via the Fischer Tropsch catalytic process. The other two are derived from Camelina oil and tallow via hydroprocessing. The traditional military jet fuel, JP8, is used as a baseline as it is derived from petroleum. The sixth fuel is derived from petroleum and is used to study the effects of aromatic content on the synthetic fuels. The synthetic fuels lack aromatic compounds, which are an important class of hydrocarbons necessary for fuel handling systems to function properly. Several single-component fuels are studied (through models and/or experiments) to facilitate interpretation and understanding. The flame stability study first compares all the 'real', complex fuels for blowout. A toroidal stirred reactor is used to try and isolate temperature and chemical effects. The modeling study of blowout in the toroidal reactor is the key to understanding any fuel-based differences in blowout behavior. A detailed, reacting CFD model of methane is used to understand how the reactor stabilizes the flame and how that changes as the reactor approaches blowout. A 22 species reduced form of GRI 3.0 is used to model methane chemistry. The knowledge of the radical species role is utilized to investigate the differences between a highly aliphatic fuel (surrogated by iso-octane) and a highly aromatic fuel (surrogated by toluene). A perfectly stirred reactor model is used to study the chemical kinetic pathways for these fuels near blowout. The

  6. Characterization of jet breakup mechanisms observed from simulant experiments of molten fuel penetrating coolant. Technical progress report, FY 1992

    SciTech Connect

    Jones, B.G.

    1992-08-01

    The goal of this research program has been to add to our understanding of the breakup of molten fuel jets penetrating reactor coolant. Easily handled working fluids are used to simulate fuel jet breakup, so that detailed observations may be obtained from a relatively large number of experiments. The tools used for observing this behavior are high speed notion picture photography, Flash X-radiography, and X-ray cine. Jet breakup lengths are determined from motion pictures; the mechanisms by which the jets are fragmented may be inferred from radiographs.

  7. Direct numerical simulation of ignition in turbulent n-heptane liquid-fuel spray jets

    SciTech Connect

    Wang, Y.; Rutland, C.J.

    2007-06-15

    Direct numerical simulation was used for fundamental studies of the ignition of turbulent n-heptane liquid-fuel spray jets. A chemistry mechanism with 33 species and 64 reactions was adopted to describe the chemical reactions. The Eulerian method is employed to solve the carrier-gas flow field and the Lagrangian method is used to track the liquid-fuel droplets. Two-way coupling interaction is considered through the exchange of mass, momentum, and energy between the carrier-gas fluid and the liquid-fuel spray. The initial carrier-gas temperature was 1500 K. Six cases were simulated with different droplet radii (from 10 to 30 {mu}m) and two initial velocities (100 and 150 m/s). From the simulations, it was found that evaporative cooling and turbulence mixing play important roles in the ignition of liquid-fuel spray jets. Ignition first occurs at the edges of the jets where the fuel mixture is lean, and the scalar dissipation rate and the vorticity magnitude are very low. For smaller droplets, ignition occurs later than for larger droplets due to increased evaporative cooling. Higher initial droplet velocity enhances turbulence mixing and evaporative cooling. For smaller droplets, higher initial droplet velocity causes the ignition to occur earlier, whereas for larger droplets, higher initial droplet velocity delays the ignition time. (author)

  8. Toxicity of Jet A (aviation fuel) selected aquatic organisms. Technical report, August 1987-February 1988

    SciTech Connect

    Haley, M.V.; Landis, W.G.

    1989-03-01

    JP8 (jet propulsion) is an aviation fuel being considered for replacement of diesel fuel used in the generation of smoke on the battlefield. JP8 is projected to be more economical and also be used as a fuel for the ground machinery used in the transport and dissemination of JP8. Also, fog oil has naphthene constituents above the Occupational Safety and Health Administration (OSHA) standards. JP8 trailing and testing could lead to contaminating surrounding aquatic ecosystems through runoff or wind transport. Therefore, the toxicity of JP8 to aquatic organisms must be known. Jet A (aviation fuel) was substituted for JP8 due to availability and similar distillation procedure. The aquatic toxicity of the soluble fraction of Jet A (aviation fuel) was examined. Acute 48-hr bioassays were performed using the water flea, Daphnia magna, and 96-hr growth inhibition bioassays were performed using a green unicellular alga, Selenastrum capricornutum. All tests were conducted according to guidelines set by the U.S. Environmental Protection Agency (EPA) and the American Society for Testing and Materials (ASTM). The 48-hr EC50 for D. magna was 3.1 mg/L. The 96-hr IC50 for S. capricornutum was 4.2 mg/L.

  9. Preliminary Investigation of Performance and Starting Characteristics of Liquid Fluorine : Liquid Oxygen Mixtures with Jet Fuel

    NASA Technical Reports Server (NTRS)

    Rothenberg, Edward A; Ordin, Paul M

    1954-01-01

    The performance of jet fuel with an oxidant mixture containing 70 percent liquid fluorine and 30 percent liquid oxygen by weight was investigated in a 500-pound-thrust engine operating at a chamber pressure of 300 pounds per square inch absolute. A one-oxidant-on-one-fuel skewed-hole impinging-jet injector was evaluated in a chamber of characteristic length equal to 50 inches. A maximum experimental specific impulse of 268 pound-seconds per pound was obtained at 25 percent fuel, which corresponds to 96 percent of the maximum theoretical specific impulse based on frozen composition expansion. The maximum characteristic velocity obtained was 6050 feet per second at 23 percent fuel, or 94 percent of the theoretical maximum. The average thrust coefficient was 1.38 for the 500-pound thrust combustion-chamber nozzle used, which was 99 percent of the theoretical (frozen) maximum. Mixtures of fluorine and oxygen were found to be self-igniting with jet fuel with fluorine concentrations as low as 4 percent, when low starting propellant flow rated were used.

  10. 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.

  11. Jet fuel property changes and their effect on producibility and cost in the U.S., Canada, and Europe

    NASA Technical Reports Server (NTRS)

    Varga, G. M., Jr.; Avella, A. J., Jr.; Cunningham, A. R.; Featherston, C. D.; Gorgol, J. F.; Graf, A. J.; Lieberman, M.; Oliver, G. A.

    1985-01-01

    The effects of changes in properties and blending stocks on the refinery output and cost of jet fuel in the U.S., Canada, and Europe were determined. Computerized refinery models that minimize production costs and incorporated a 1981 cost structure and supply/demand projections to the year 2010 were used. Except in the West U.S., no changes in jet fuel properties were required to meet all projected demands, even allowing for deteriorating crude qualities and changes in competing product demand. In the West U.S., property changes or the use of cracked blendstocks were projected to be required after 1990 to meet expected demand. Generally, relaxation of aromatics and freezing point, or the use of cracked stocks produced similar results, i.e., jet fuel output could be increased by up to a factor of three or its production cost lowered by up to $10/cu m. High quality hydrocracked stocks are now used on a limited basis to produce jet fuel. The conversion of U.S. and NATO military forces from wide-cut to kerosene-based jet fuel is addressed. This conversion resulted in increased costs of several hundred million dollars annually. These costs can be reduced by relaxing kerosene jet fuel properties, using cracked stocks and/or considering the greater volumetric energy content of kerosene jet fuel.

  12. FAR-TECH's Nanoparticle Plasma Jet System and its Application to Disruptions, Deep Fueling, and Diagnostics

    NASA Astrophysics Data System (ADS)

    Thompson, J. R.; Bogatu, I. N.; Galkin, S. A.; Kim, J. S.

    2012-10-01

    Hyper-velocity plasma jets have potential applications in tokamaks for disruption mitigation, deep fueling and diagnostics. Pulsed power based solid-state sources and plasma accelerators offer advantages of rapid response and mass delivery at high velocities. Fast response is critical for some disruption mitigation scenario needs, while high velocity is especially important for penetration into tokamak plasma and its confining magnetic field, as in the case of deep fueling. FAR-TECH is developing the capability of producing large-mass hyper-velocity plasma jets. The prototype solid-state source has produced: 1) >8.4 mg of H2 gas only, and 2) >25 mg of H2 and >180 mg of C60 in a H2/C60 gas mixture. Using a coaxial plasma gun coupled to the source, we have successfully demonstrated the acceleration of composite H/C60 plasma jets, with momentum as high as 0.6 g.km/s, and containing an estimated C60 mass of ˜75 mg. We present the status of FAR-TECH's nanoparticle plasma jet system and discuss its application to disruptions, deep fueling, and diagnostics. A new TiH2/C60 solid-state source capable of generating significantly higher quantities of H2 and C60 in <0.5 ms will be discussed.

  13. Experimental verification of the thermodynamic properties for a jet-A fuel

    NASA Technical Reports Server (NTRS)

    Graciasalcedo, Carmen M.; Brabbs, Theodore A.; Mcbride, Bonnie J.

    1988-01-01

    Thermodynamic properties for a Jet-A fuel were determined by Shell Development Company in 1970 under a contract for NASA Lewis Research Center. The polynomial fit necessary to include Jet-A fuel (liquid and gaseous phases) in the library of thermodynamic properties of the NASA Lewis Chemical Equilibrium Program is calculated. To verify the thermodynamic data, the temperatures of mixtures of liquid Jet-A injected into a hot nitrogen stream were experimentally measured and compared to those calculated by the program. Iso-octane, a fuel for which the thermodynamic properties are well known, was used as a standard to calibrate the apparatus. The measured temperatures for the iso-octane/nitrogen mixtures reproduced the calculated temperatures except for a small loss due to the non-adiabatic behavior of the apparatus. The measurements for Jet-A were corrected for this heat loss and showed excellent agreement with the calculated temperatures. These experiments show that this process can be adequately described by the thermodynamic properties fitted for the Chemical Equilibrium Program.

  14. 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

  15. 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.

  16. Mast cells mediate the immune suppression induced by dermal exposure to JP-8 jet fuel.

    PubMed

    Limón-Flores, Alberto Y; Chacón-Salinas, Rommel; Ramos, Gerardo; Ullrich, Stephen E

    2009-11-01

    Applying jet propulsion-8 (JP-8) jet fuel to the skin of mice induces immune suppression. Applying JP-8 to the skin of mice suppresses T-cell-mediated immune reactions including, contact hypersensitivity (CHS) delayed-type hypersensitivity and T-cell proliferation. Because dermal mast cells play an important immune regulatory role in vivo, we tested the hypothesis that mast cells mediate jet fuel-induced immune suppression. When we applied JP-8 to the skin of mast cell deficient mice CHS was not suppressed. Reconstituting mast cell deficient mice with wild-type bone marrow derived mast cells (mast cell "knock-in mice") restored JP-8-induced immune suppression. When, however, mast cells from prostaglandin E(2) (PGE(2))-deficient mice were used, the ability of JP-8 to suppress CHS was not restored, indicating that mast cell-derived PGE(2) was activating immune suppression. Examining the density of mast cells in the skin and lymph nodes of JP-8-treated mice indicated that jet fuel treatment caused an initial increase in mast cell density in the skin, followed by increased numbers of mast cells in the subcutaneous space and then in draining lymph nodes. Applying JP-8 to the skin increased mast cell expression of CXCR4, and increased the expression of CXCL12 by draining lymph node cells. Because CXCL12 is a chemoattractant for CXCR4+ mast cells, we treated JP-8-treated mice with AMD3100, a CXCR4 antagonist. AMD3100 blocked the mobilization of mast cells to the draining lymph node and inhibited JP-8-induced immune suppression. Our findings demonstrate the importance of mast cells in mediating jet fuel-induced immune suppression.

  17. Application study of filamentary composites in a commercial jet aircraft fuselage

    NASA Technical Reports Server (NTRS)

    Johnson, R. W.; June, R. R.

    1972-01-01

    A study of applications of filamentary composite materials to aircraft fuselage structure was performed. General design criteria were established and material studies conducted using the 727-200 forebody as the primary structural component. Three design approaches to the use of composites were investigated: uniaxial reinforcement of metal structure, uniaxial and biaxial reinforcement of metal structure, and an all-composite design. Materials application studies for all three concepts were conducted on fuselage shell panels, keel beam, floor beams, floor panels, body frames, fail-safe straps, and window frames. Cost benefit studies were conducted and developmental program costs estimated. On the basis of weight savings, cost effectiveness, developmental program costs, and potential for early application on commercial aircraft, the unaxial design is recommended for a 5-year flight service evaluation program.

  18. An investigation of air solubility in Jet A fuel at high pressures

    NASA Technical Reports Server (NTRS)

    Faeth, G. M.

    1981-01-01

    Problems concerned with the supercritical injection concept are discussed. Supercritical injection involves dissolving air into a fuel prior to injection. A similar effect is obtained by preheating the fuel so that a portion of the fuel flashes when its pressure is reduced. Flashing improves atomization properties and the presence of air in the primary zone of a spray flame reduces the formation of pollutants. The investigation is divided into three phases: (1) measure the solubility and density properties of fuel/gas mixtures, including Jet A/air, at pressures and correlate these results using theory; (2) investigate the atomization properties of flashing liquids, including fuel/dissolved gas systems. Determine and correlate the effect of inlet properties and injector geometry on mass flow rates, Sauter mean diameter and spray angles; (3) examine the combustion properties of flashing injection in an open burner flame, considering flame shape and soot production.

  19. 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.

  20. Life cycle greenhouse gas emissions of sugar cane renewable jet fuel.

    PubMed

    Moreira, Marcelo; Gurgel, Angelo C; Seabra, Joaquim E A

    2014-12-16

    This study evaluated the life cycle GHG emissions of a renewable jet fuel produced from sugar cane in Brazil under a consequential approach. The analysis included the direct and indirect emissions associated with sugar cane production and fuel processing, distribution, and use for a projected 2020 scenario. The CA-GREET model was used as the basic analytical tool, while Land Use Change (LUC) emissions were estimated employing the GTAP-BIO-ADV and AEZ-EF models. Feedstock production and LUC impacts were evaluated as the main sources of emissions, respectively estimated as 14.6 and 12 g CO2eq/MJ of biofuel in the base case. However, the renewable jet fuel would strongly benefit from bagasse and trash-based cogeneration, which would enable a net life cycle emission of 8.5 g CO2eq/MJ of biofuel in the base case, whereas Monte Carlo results indicate 21 ± 11 g CO2eq/MJ. Besides the major influence of the electricity surplus, the sensitivity analysis showed that the cropland-pasture yield elasticity and the choice of the land use factor employed to sugar cane are relevant parameters for the biofuel life cycle performance. Uncertainties about these estimations exist, especially because the study relies on projected performances, and further studies about LUC are also needed to improve the knowledge about their contribution to the renewable jet fuel life cycle.

  1. Investigation of jet fuel thermal stability using photon correlation spectroscopy and a quartz crystal microbalance

    SciTech Connect

    Trott, W.M.

    1995-12-31

    In order to provide input for the development of predictive models of jet fuel degradation and deposition of solids, an experimental assembly for integrated photon correlation spectroscopy (PCS) and quartz crystal microbalance (QCM) measurements on heated fuels has been designed and tested. PCS provides in situ, real-time monitoring of particle formation in the liquid while the microbalance system yields complementary measurements of mass desposited on a surface. Materials examined include Jet A POSF-2827, a non-hydro-treated fuel, and Jet A POSF-2747 (high hydro-treated). POSF-2827 rapidly generates large numbers of submicron-diameter particles at modest temperatures (T=130-150{degrees}C). After a few hours, this process leads to multiple scattering effects that complicate interpretation of PCS data. Mass deposition rates (as measured by the QCM) range from 0.2-0.9 {mu}g-cm{sup -2}-hr{sup -1} over the same temperature range. Lower particle formation and deposition rates are seen with the hydro-treated fuel.

  2. Measured noise reductions resulting from modified approach procedures for business jet aircraft

    NASA Technical Reports Server (NTRS)

    Burcham, F. W., Jr.; Putnam, T. W.; Lasagna, P. L.; Parish, O. O.

    1975-01-01

    Five business jet airplanes were flown to determine the noise reductions that result from the use of modified approach procedures. The airplanes tested were a Gulfstream 2, JetStar, Hawker Siddeley 125-400, Sabreliner-60 and LearJet-24. Noise measurements were made 3, 5, and 7 nautical miles from the touchdown point. In addition to a standard 3 deg glide slope approach, a 4 deg glide slope approach, a 3 deg glide slope approach in a low-drag configuration, and a two-segment approach were flown. It was found that the 4 deg approach was about 4 EPNdB quieter than the standard 3 deg approach. Noise reductions for the low-drag 3 deg approach varied widely among the airplanes tested, with an average of 8.5 EPNdB on a fleet-weighted basis. The two-segment approach resulted in noise reductions of 7 to 8 EPNdB at 3 and 5 nautical miles from touchdown, but only 3 EPNdB at 7 nautical miles from touchdown when the airplanes were still in level flight prior to glide slope intercept. Pilot ratings showed progressively increasing workload for the 4 deg, low-drag 3 deg, and two-segment approaches.

  3. 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.

  4. 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.

  5. Effects of potential additives to promote seal swelling on the thermal stability of synthetic jet fuels

    SciTech Connect

    Lind, D.D.; Gormley, R.G.; Zandhuis, P.H.; Baltrus, J.P.

    2007-10-01

    Synthetic fuels derived from the Fischer-Tropsch (F-T) process using natural gas or coal-derived synthesis gas as feedstocks can be used for powering of ground vehicles, aircraft and ships. Because of their chemical and physical properties, F-T fuels will probably require additives in order to meet specifications with respect to lubricity and seal swell capability for use in ground and air vehicles. These additives can include oxygenates and compounds containing other heteroatoms that may adversely affect thermal stability. In order to understand what additives will be the most beneficial, a comprehensive experimental and computational study of conventional and additized fuels has been undertaken. The experimental approach includes analysis of the trace oxygenate and nitrogen-containing compounds present in conventional petroleum-derived fuels and trying to relate their presence (or absence) to changes in the desired properties of the fuels. This paper describes the results of efforts to test the thermal stability of synthetic fuels and surrogate fuels containing single-component additives that have been identified in earlier research as the best potential additives for promoting seal swelling in synthetic fuels, as well as mixtures of synthetic and petroleum-derived fuels.

  6. Transpiration cooling in the locality of a transverse fuel jet for supersonic combustors

    NASA Technical Reports Server (NTRS)

    Northam, G. Burton; Capriotti, Diego P.; Byington, Carl S.

    1990-01-01

    The objective of the current work was to determine the feasibility of transpiration cooling for the relief of the local heating rates in the region of a sonic, perpendicular, fuel jet of gaseous hydrogen. Experiments were conducted to determine the interaction between the cooling required and flameholding limits of a transverse jet in a high-enthalpy, Mach 3 flow in both open-jet and direct-connect test mode. Pulsed shadowgraphs were used to illustrate the flow field. Infrared thermal images indicated the surface temperatures, and the OH(-) emission of the flame was used to visualize the limits of combustion. Wall, static presures indicated the location of the combustion within the duct and were used to calculate the combustion efficiency. The results from both series of tests at facility total temperatures of 1700 K and 2000 K are presented.

  7. Mixing of Pure Air Jets with a Reacting Fuel-Rich Crossflow

    NASA Technical Reports Server (NTRS)

    Leong, M. Y.; Samuelsen, G. S.; Holdeman, J. D.

    1997-01-01

    Jets in a crossflow play an integral role in practical combustion systems such as can and annular gas turbine combustors in conventional systems, and the Rich-burn/Quick-mix/Lean-burn (RQL) combustor utilized in stationary applications and proposed for advanced subsonic and supersonic transports. The success of the RQL combustor rests with the performance of the quick-mixing section that bridges the rich and lean zones. The mixing of jet air with a rich crossflow to bring the reaction to completion in the lean zone must be performed rapidly and thoroughly in order to decrease the extent of near-stoichiometric fluid pocket formation. Fluid pockets at near-stoichiometric equivalence ratios are undesirable because the high temperatures attained accelerate pollutant formation kinetics associated with nitric oxide (NO). The present study develops a model experiment designed to reveal the processes that occur when jet air is introduced into hot effluent emanating from a fuel-rich reaction zone.

  8. Oxygen and Fuel Jet Diffusion Flame Studies in Microgravity Motivated by Spacecraft Oxygen Storage Fire Safety

    NASA Technical Reports Server (NTRS)

    Sunderland, P. B.; Yuan, Z.-G.; Krishnan, S. S.; Abshire, J. M.; Gore, J. P.

    2003-01-01

    Owing to the absence of past work involving flames similar to the Mir fire namely oxygen-enhanced, inverse gas-jet diffusion flames in microgravity the objectives of this work are as follows: 1. Observe the effects of enhanced oxygen conditions on laminar jet diffusion flames with ethane fuel. 2. Consider both earth gravity and microgravity. 3. Examine both normal and inverse flames. 4. Compare the measured flame lengths and widths with calibrated predictions of several flame shape models. This study expands on the work of Hwang and Gore which emphasized radiative emissions from oxygen-enhanced inverse flames in earth gravity, and Sunderland et al. which emphasized the shapes of normal and inverse oxygen-enhanced gas-jet diffusion flames in microgravity.

  9. A Characterization and Evaluation of Coal Liquefaction Process Streams. Results of Inspection Tests on Nine Coal-Derived Distillation Cuts in the Jet Fuel Boiling Range

    SciTech Connect

    S. D. Brandes; R. A. Winschel

    1999-12-30

    This report describes the assessment of the physical and chemical properties of the jet fuel (180-300 C) distillation fraction of nine direct coal liquefaction products and compares those properties to the corresponding specifications for aviation turbine fuels. These crude coal liquids were compared with finished fuel specifications specifically to learn what the refining requirements for these crudes will be to make them into finished fuels. The properties of the jet fuel fractions were shown in this work to require extensive hydrotreating to meet Jet A-1 specifications. However, these materials have a number of desirable qualities as feedstocks for the production of high energy-density jet fuels.

  10. Performance of hybrid ball bearings in oil and jet fuel

    NASA Astrophysics Data System (ADS)

    Schrader, Stephen M.; Pfaffenberger, Eugene E.

    1992-07-01

    A 308-size hybrid ball bearing, with ceramic balls and steel rings, was tested using a diester oil and gas turbine fuel as lubricants at several speeds and loads. Heat generation data from this test work was then correlated with the heat generation model from a widely used computer code. The ability of this hybrid split inner ring bearing design to endure thrust reversals, which are expected in many turbine applications, was demonstrated. Finally, the bearing was successfully endurance tested in JP-10 fuel for 25 hours at 7560 N axial load and 36,000 rpm. This work has successfully demonstrated the technology necessary to use fuel-lubricated hybrid bearings in limited-life gas turbine engine applications such as missiles, drones, and other unmanned air vehicles (UAVs). In addition, it has provided guidance for use in designing such bearing systems. As a result, the benefits of removing the conventional oil lubricant system, i.e., design simplification and reduced maintenance, can be realized.

  11. Performance of hybrid ball bearings in oil and jet fuel

    SciTech Connect

    Schrader, S.M.; Pfaffenberger, E.E. )

    1992-07-01

    A 308-size hybrid ball bearing, with ceramic balls and steel rings, was tested using a diester oil and gas turbine fuel as lubricants at several speeds and loads. Heat generation data from this test work was then correlated with the heat generation model from a widely used computer code. The ability of this hybrid split inner ring bearing design to endure thrust reversals, which are expected in many turbine applications, was demonstrated. Finally, the bearing was successfully endurance tested in JP-10 fuel for 25 hours at 7560 N axial load and 36,000 rpm. This work has successfully demonstrated the technology necessary to use fuel-lubricated hybrid bearings in limited-life gas turbine engine applications such as missiles, drones, and other unmanned air vehicles (UAVs). In addition, it has provided guidance for use in designing such bearing systems. As a result, the benefits of removing the conventional oil lubricant system, i.e., design simplification and reduced maintenance, can be realized. 6 refs.

  12. Shuttle sortie simulation using a Lear jet aircraft: Mission no. 1 (assess program)

    NASA Technical Reports Server (NTRS)

    Mulholland, D. R.; Reller, J. O., Jr.; Nell, C. B., Jr.; Mason, R. H.

    1972-01-01

    The shuttle sortie simulation mission of the Airborne Science/Shuttle Experiments System Simulation Program which was conducted using the CV-990 aircraft is reported. The seven flight, five day mission obtained data on experiment preparation, type of experiment components, operation and maintenance, data acquisition, crew functions, timelines and interfaces, use of support equipment and spare parts, power consumption, work cycles, influence of constraints, and schedule impacts. This report describes the experiment, the facilities, the operation, and the results analyzed from the standpoint of their possible use in aiding the planning for experiments in the Shuttle Sortie Laboratory.

  13. Enhanced fuel efficiency on tractor-trailers using synthetic jet-based active flow control

    NASA Astrophysics Data System (ADS)

    Amitay, Michael; Menicovich, David; Gallardo, Daniele

    2016-04-01

    The application of piezo-electrically-driven synthetic-jet-based active flow control to reduce drag on tractor-trailers was explored experimentally in wind tunnel testing as well as full-scale road tests. Aerodynamic drag accounts for more than 50% of the usable energy at highway speeds, a problem that applies primarily to trailer trucks. Therefore, a reduction in aerodynamic drag results in large saving of fuel and reduction in CO2 emissions. The active flow control technique that is being used relies on a modular system comprised of distributed, small, highly efficient actuators. These actuators, called synthetic jets, are jets that are synthesized at the edge of an orifice by a periodic motion of a piezoelectric diaphragm(s) mounted on one (or more) walls of a sealed cavity. The synthetic jet is zero net mass flux (ZNMF), but it allows momentum transfer to flow. It is typically driven near diaphragm and/or cavity resonance, and therefore, small electric input [O(10W)] is required. Another advantage of this actuator is that no plumbing is required. The system doesn't require changes to the body of the truck, can be easily reconfigured to various types of vehicles, and consumes small amounts of electrical power from the existing electrical system of the truck. Preliminary wind tunnel results showed up to 18% reduction in fuel consumption, whereas road tests also showed very promising results.

  14. Hydrocarbon group type determination in jet fuels by high performance liquid chromatography

    NASA Technical Reports Server (NTRS)

    Antoine, A. C.

    1977-01-01

    Results are given for the analysis of some jet and diesel fuel samples which were prepared from oil shale and coal syncrudes. Thirty-two samples of varying chemical composition and physical properties were obtained. Hydrocarbon types in these samples were determined by fluorescent indicator adsorption (FIA) analysis, and the results from three laboratories are presented and compared. Recently, rapid high performance liquid chromatography (HPLC) methods have been proposed for hydrocarbon group type analysis, with some suggestion for their use as a replacement of the FIA technique. Two of these methods were used to analyze some of the samples, and these results are also presented and compared. Two samples of petroleum-based Jet A fuel are similarly analyzed.

  15. Fuel system design concepts for broad property fuels

    NASA Technical Reports Server (NTRS)

    Versaw, E. F.

    1984-01-01

    The results of a study assessing the impact of using jet fuel with relaxed specification properties on an aircraft fuel system are given. The study objectives were to identify credible values for specific fuel properties which might be relaxed, to evolve advanced fuel system designs for airframe and engines which would permit use of the specified relaxed properties fuels, and to evaluate performance of the candidate advanced fuel systems and the relaxed property fuels in a typical transport aircraft. The study used, as a baseline, the fuel system incorporated in the Lockheed Tristar. This aircraft is powered by three RB.211-524 Rolls-Royce engines and incorporates a Pratt and Whitney ST6C-421 auxiliary power unit for engine starting and inflight emergency electrical power. The fuel property limits examined are compared with commercial Jet A kerosene and the NASA RFP fuel properties. A screening of these properties established that a higher freezing point and a lower thermal stability would impact fuel system design more significantly than any of the other property changes. Three candidate fuel systems which combine the ability to operate with fuels having both a high freeze point and a low thermal stability are described. All candidates employ bleed air to melt fuel freeze-out prior to starting the APU or an inoperable engine. The effects of incorporating these systems on aircraft weight and engine specific fuel consumption are given.

  16. 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.

  17. 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.

  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. 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.

  20. 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.

  1. 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.

  2. Synthesis of jet fuel range branched cycloalkanes with mesityl oxide and 2-methylfuran from lignocellulose.

    PubMed

    Li, Shanshan; Li, Ning; Wang, Wentao; Li, Lin; Wang, Aiqin; Wang, Xiaodong; Zhang, Tao

    2016-01-01

    Jet fuel range branched cycloalkanes with high density (0.82 g mL(-1)) and low freezing point (217-219 K) was first prepared by the solvent-free intramolecular aldol condensation of the trione from the hydrolysis of the alkylation product of mesityl oxide and 2-methylfuran (or the one-pot reaction of mesityl oxide, 2-methylfuran and water), followed by hydrodeoxygenation (HDO). PMID:27582417

  3. Synthesis of jet fuel range branched cycloalkanes with mesityl oxide and 2-methylfuran from lignocellulose

    PubMed Central

    Li, Shanshan; Li, Ning; Wang, Wentao; Li, Lin; Wang, Aiqin; Wang, Xiaodong; Zhang, Tao

    2016-01-01

    Jet fuel range branched cycloalkanes with high density (0.82 g mL−1) and low freezing point (217–219 K) was first prepared by the solvent-free intramolecular aldol condensation of the trione from the hydrolysis of the alkylation product of mesityl oxide and 2-methylfuran (or the one-pot reaction of mesityl oxide, 2-methylfuran and water), followed by hydrodeoxygenation (HDO). PMID:27582417

  4. Synthesis of jet fuel range branched cycloalkanes with mesityl oxide and 2-methylfuran from lignocellulose

    NASA Astrophysics Data System (ADS)

    Li, Shanshan; Li, Ning; Wang, Wentao; Li, Lin; Wang, Aiqin; Wang, Xiaodong; Zhang, Tao

    2016-09-01

    Jet fuel range branched cycloalkanes with high density (0.82 g mL‑1) and low freezing point (217–219 K) was first prepared by the solvent-free intramolecular aldol condensation of the trione from the hydrolysis of the alkylation product of mesityl oxide and 2-methylfuran (or the one-pot reaction of mesityl oxide, 2-methylfuran and water), followed by hydrodeoxygenation (HDO).

  5. Partitioning behavior of aromatic components in jet fuel into diverse membrane-coated fibers.

    PubMed

    Baynes, Ronald E; Xia, Xin-Rui; Barlow, Beth M; Riviere, Jim E

    2007-11-01

    Jet fuel components are known to partition into skin and produce occupational irritant contact dermatitis (OICD) and potentially adverse systemic effects. The purpose of this study was to determine how jet fuel components partition (1) from solvent mixtures into diverse membrane-coated fibers (MCFs) and (2) from biological media into MCFs to predict tissue distribution. Three diverse MCFs, polydimethylsiloxane (PDMS, lipophilic), polyacrylate (PA, polarizable), and carbowax (CAR, polar), were selected to simulate the physicochemical properties of skin in vivo. Following an appropriate equilibrium time between the MCF and dosing solutions, the MCF was injected directly into a gas chromatograph/mass spectrometer (GC-MS) to quantify the amount that partitioned into the membrane. Three vehicles (water, 50% ethanol-water, and albumin-containing media solution) were studied for selected jet fuel components. The more hydrophobic the component, the greater was the partitioning into the membranes across all MCF types, especially from water. The presence of ethanol as a surrogate solvent resulted in significantly reduced partitioning into the MCFs with discernible differences across the three fibers based on their chemistries. The presence of a plasma substitute (media) also reduced partitioning into the MCF, with the CAR MCF system being better correlated to the predicted partitioning of aromatic components into skin. This study demonstrated that a single or multiple set of MCF fibers may be used as a surrogate for octanol/water systems and skin to assess partitioning behavior of nine aromatic components frequently formulated with jet fuels. These diverse inert fibers were able to assess solute partitioning from a blood substitute such as media into a membrane possessing physicochemical properties similar to human skin. This information may be incorporated into physiologically based pharmacokinetic (PBPK) models to provide a more accurate assessment of tissue dosimetry of

  6. Effect of esters on lubricity of hydrotreated jet fuel

    SciTech Connect

    Kislenko, A.S.; Krylov, I.F.; Sokolova, G.I.; Vishnyakova, T.P.

    1985-07-01

    The authors synthesized a number of esters of stearic acid with polyhydric alcohols and ran comparative tests on aliphatic alcohols to determine their effects on the antiwear properties of the fuel. They conclude that the differences in effectiveness in improving the lubricity by the use of aliphatic alcohols and the full and partial esters of polyhydric alcohols and stearic acid can be explained by the presence of hydroxyl and ester groups close to each other in partial esters. This is reflected in the higher polarity of the partial esters, a higher rate of adsorption, and a stronger bonding of the adsorbed layer to the metal surface.

  7. 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.

  8. Investigation of air solubility in jet A fuel at high pressures

    NASA Technical Reports Server (NTRS)

    Rupprecht, S. D.; Faeth, G. M.

    1981-01-01

    The solubility and density properties of saturated mixtures of fuels and gases were measured. The fuels consisted of Jet A and dodecane, the gases were air and nitrogen. The test range included pressures of 1.03 to 10.34 MPa and temperatures of 298 to 373 K. The results were correlated successfully, using the Soave equation of state. Over this test range, dissolved gas concentrations were roughly proportional to pressure and increased slightly with increasing temperature. Mixture density was relatively independent of dissolved gas concentration.

  9. Advanced thermally stable jet fuels. Technical progress report, October 1993--December 1993

    SciTech Connect

    Schobert, H.H.; Eser, S.; Song, C.; Hatcher, P.G.; Walsh, P.M.; Coleman, M.M.

    1994-01-01

    The Penn State program in advancd thermally stable coal-based jet fuels has five broad objectives: (1) development of mechanisms of degradation and solids formation; (2) quantitative measurement of growth of sub-micrometer and micrometer-sized particles suspended in fuels during thermal stressing; (3) characterization of carbonaceous deposits by various instrumental and microscopic methods; (4) elucidation of the role of additives in retarding them formation of vcarbonaceous solids; and, (5) assessment of the potential of production of high yields of cycloalkanes by direct liquefaction of coal.

  10. Plain-jet airblast atomization of alternative liquid petroleum fuels under high ambient air pressure conditions

    NASA Astrophysics Data System (ADS)

    Jasuja, A. K.

    1982-04-01

    The effects that air and fuel properties have upon the spray mean drop size characteristics of a plain-jet airblast atomizer of the type employed in the gas turbine engine are investigated. The tests used kerosene, gas oil and a high-viscosity blend of gas oil in residual fuel oil, and covered a wide range of ambient air pressures. Laser light-scattering technique was employed for drop size measurements. It is concluded that the atomizer's measured mean drop size characteristics are only slightly different from those of the pre-filming type, especially when operating on low-viscosity kerosene under higher ambient air pressure. The beneficial effect of increased levels of ambient air pressure on mean drop size is shown to be much reduced in the case of high-viscosity fuels, thus making the attainment of good atomization performance on such fuels difficult. An expression is derived for correlating the obtained mean drop size data.

  11. REFINERY INTEGRATION OF BY-PRODUCTS FROM COAL-DERIVED JET FUELS

    SciTech Connect

    Leslie R. Rudnick; Andre Boehman; Chunshan Song; Bruce Miller; Gareth Mitchell

    2005-05-18

    This report summarizes the accomplishments toward project goals during the first six months of the second year of the project to assess the properties and performance of coal based products. These products are in the gasoline, diesel and fuel oil range and result from coal based jet fuel production from an Air Force funded program. Specific areas of progress include generation of coal based material that has been fractionated into the desired refinery cuts, acquisition and installation of a research gasoline engine, and modification of diesel engines for use in evaluating diesel produced in the project. The desulfurization of sulfur containing components of coal and petroleum is being studied so that effective conversion of blended coal and petroleum streams can be efficiently converted to useful refinery products. Equipment is now in place to begin fuel oil evaluations to assess the quality of coal based fuel oil. Coal samples have procured and are being assessed for cleaning prior to use in coking studies.

  12. Exhaust emissions from a premixing, prevaporizing flame tube using liquid jet A fuel

    NASA Technical Reports Server (NTRS)

    Marek, C. J.; Papathakos, L. C.

    1976-01-01

    Emissions of nitrogen oxides, carbon monoxide, and unburned hydrocarbons were measured in a burner where liquid Jet A fuel was sprayed into the heated air stream and vaporized upstream of a perforated plate flameholder. The burner was tested at inlet air temperatures at 640, 800, and 833 K, an inlet pressure of 5.6 X 100,000 N/m squared, a reference velocity of 25 m/sec, and equivalence ratios from lean blowout to 0.7. Nitrogen oxide levels of below 1.0 g NO2/kg fuel were obtained at combustion efficiencies greater than 99 percent. The measured emission levels for the liquid fuel agreed well with previously reported premixed gaseous propane data and agreed with well stirred reactor predictions. Autoignition of the premixed fuel air mixture was a problem at inlet temperatures above 650 K with 104 msec premixing time.

  13. Refinery Integration of By-Products from Coal-Derived Jet Fuels

    SciTech Connect

    Leslie R. Rudnick; Andre Boehman; Chunshan Song; Bruce Miller; John Andresen

    2004-09-17

    This report summarizes the accomplishments toward project goals during the first twelve months of the project to assess the properties and performance of coal based products. These products are in the gasoline, diesel and fuel oil range and result from coal based jet fuel production from an Air Force funded program. Specific areas of progress include generation of coal based material that has been fractionated into the desired refinery cuts, acquisition and installation of a research gasoline engine, and modification of diesel engines for use in evaluating diesel produced in the project. The desulfurization of sulfur containing components of coal and petroleum is being studied so that effective conversion of blended coal and petroleum streams can be efficiently converted to useful refinery products. Equipment is now in place to begin fuel oil evaluations to assess the quality of coal based fuel oil. Coal samples have procured and are being assessed for cleaning prior to use in coking studies.

  14. REFINERY INTEGRATION OF BY-PRODUCTS FROM COAL-DERIVED JET FUELS

    SciTech Connect

    Leslie R. Rudnick; Andre Boehman; Chunshan Song; Bruce Miller; John Andresen

    2004-04-23

    This report summarizes the accomplishments toward project goals during the first six months of the project to assess the properties and performance of coal based products. These products are in the gasoline, diesel and fuel oil range and result from coal based jet fuel production from an Air Force funded program. Specific areas of progress include generation of coal based material that has been fractionated into the desired refinery cuts, acquisition and installation of a research gasoline engine, and modification of diesel engines for use in evaluating diesel produced in the project. The desulfurization of sulfur containing components of coal and petroleum is being studied so that effective conversion of blended coal and petroleum streams can be efficiently converted to useful refinery products. Equipment is now in place to begin fuel oil evaluations to assess the quality of coal based fuel oil. Coal samples have procured and are being assessed for cleaning prior to use in coking studies.

  15. Reduced Equations for Calculating the Combustion Rates of Jet-A and Methane Fuel

    NASA Technical Reports Server (NTRS)

    Molnar, Melissa; Marek, C. John

    2003-01-01

    Simplified kinetic schemes for Jet-A and methane fuels were developed to be used in numerical combustion codes, such as the National Combustor Code (NCC) that is being developed at Glenn. These kinetic schemes presented here result in a correlation that gives the chemical kinetic time as a function of initial overall cell fuel/air ratio, pressure, and temperature. The correlations would then be used with the turbulent mixing times to determine the limiting properties and progress of the reaction. A similar correlation was also developed using data from NASA's Chemical Equilibrium Applications (CEA) code to determine the equilibrium concentration of carbon monoxide as a function of fuel air ratio, pressure, and temperature. The NASA Glenn GLSENS kinetics code calculates the reaction rates and rate constants for each species in a kinetic scheme for finite kinetic rates. These reaction rates and the values obtained from the equilibrium correlations were then used to calculate the necessary chemical kinetic times. Chemical kinetic time equations for fuel, carbon monoxide, and NOx were obtained for both Jet-A fuel and methane.

  16. Effect of advanced technology and fuel efficient engine on a supersonic-cruise executive jet with a small cabin

    NASA Technical Reports Server (NTRS)

    Beissner, F. L., Jr.; Lovell, W. A.; Robins, A. W.; Swanson, E. E.

    1983-01-01

    An analytical study of a supersonic-cruise, executive, jet aircraft indicated the effects of using advanced technology. The twin-engine, arrow-wing vehicle was configured with a cabin of minimum practical size to hold one pilot, eight passengers, and their baggage. The primary differences between this configuration that of a previous report were the reduction in cabin size and the use of engines that are more fuel-efficient. Both conceptual vehicles are capable of forming the same mission. The current vehicle has a range of 3,350 nautical miles at Mach 2.3 cruise and 2,700 nautical miles at Mach 0.9. The concept description includes configuration definition, aerodynamic and propulsion-system characteristics, and mass properties. Performance analyses are documented for intercontinental and transcontinental flight profiles. In the latter case, a reduction in sonic-boom overpressure from 1.3 to 1.0 pounds per square foot was achieved by varying the flight profile slightly from that for optimum performance.

  17. Synthesis and analysis of jet fuel from shale oil and coal syncrudes

    NASA Technical Reports Server (NTRS)

    Gallagher, J. P.; Collins, T. A.; Nelson, T. J.; Pedersen, M. J.; Robison, M. G.; Wisinski, L. J.

    1976-01-01

    Thirty-two jet fuel samples of varying properties were produced from shale oil and coal syncrudes, and analyzed to assess their suitability for use. TOSCO II shale oil and H-COAL and COED syncrudes were used as starting materials. The processes used were among those commonly in use in petroleum processing-distillation, hydrogenation and catalytic hydrocracking. The processing conditions required to meet two levels of specifications regarding aromatic, hydrogen, sulfur and nitrogen contents at two yield levels were determined and found to be more demanding than normally required in petroleum processing. Analysis of the samples produced indicated that if the more stringent specifications of 13.5% hydrogen (min.) and 0.02% nitrogen (max.) were met, products similar in properties to conventional jet fuels were obtained. In general, shale oil was easier to process (catalyst deactivation was seen when processing coal syncrudes), consumed less hydrogen and yielded superior products. Based on these considerations, shale oil appears to be preferred to coal as a petroleum substitute for jet fuel production.

  18. Toward a second generation fuel efficient supersonic cruise aircraft performance characteristics and benefits

    NASA Technical Reports Server (NTRS)

    Vachal, J. D.

    1976-01-01

    The need for greatly improved fuel efficiency and off-design subsonic characteristics is discussed. Engine-airframe matching studies are presented which show the benefits of a configuration designed for much lower supersonic drag levels (blended wing-fuselage) and how well this airframe matches with the new advanced variable-cycle engines. The benefits of advanced takeoff procedures and systems together with the co-annular noise effect in achieving low noise levels with a small cruise-sized engine are discussed. It is concluded that the technology advances when carefully integrated through detailed engine-airframe matching studies on a validated baseline airplane lead to a much improved supersonic cruise aircraft, i.e., more range, less fuel consumption, noise flexibility and satisfactory off-design characteristics.

  19. 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

  20. 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.

  1. Analysis of a topping-cycle, aircraft, gas-turbine-engine system which uses cryogenic fuel

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

    A topping-cycle aircraft engine system which uses a cryogenic fuel was investigated. This system consists of a main turboshaft engine that 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) 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 with that of the reference turboshaft engine.

  2. 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.

  3. Refinery Integration of By-Products from Coal-Derived Jet Fuels

    SciTech Connect

    Caroline E. Burgess Clifford; Andre Boehman; Chunshan Song; Bruce Miller; Gareth Mitchell

    2006-05-17

    This report summarizes the accomplishments toward project goals during the first six months of the third year of the project to assess the properties and performance of coal based products. These products are in the gasoline, diesel and fuel oil range and result from coal based jet fuel production from an Air Force funded program. Specific areas of progress include generation of coal based material that has been fractionated into the desired refinery cuts, acquisition and installation of a research gasoline engine, and modification of diesel engines for use in evaluating diesel produced in the project. Characterization of the gasoline fuel indicates a dominance of single ring alkylcycloalkanes that have a low octane rating; however, blends containing these compounds do not have a negative effect upon gasoline when blended in refinery gasoline streams. Characterization of the diesel fuel indicates a dominance of 3-ring aromatics that have a low cetane value; however, these compounds do not have a negative effect upon diesel when blended in refinery diesel streams. The desulfurization of sulfur containing components of coal and petroleum is being studied so that effective conversion of blended coal and petroleum streams can be efficiently converted to useful refinery products. Equipment is now in place to begin fuel oil evaluations to assess the quality of coal based fuel oil. Combustion and characterization of fuel oil indicates that the fuel is somewhere in between a No. 4 and a No. 6 fuel oil. Emission testing indicates the fuel burns similarly to these two fuels, but trace metals for the coal-based material are different than petroleum-based fuel oils. Co-coking studies using cleaned coal are highly reproducible in the pilot-scale delayed coker. Evaluation of the coke by Alcoa, Inc. indicated that while the coke produced is of very good quality, the metals content of the carbon is still high in iron and silica. Coke is being evaluated for other possible uses

  4. Fuel Regression Characteristics of Cascaded Multistage Impinging-Jet (CAMUI) Type Hybrid Rocket

    NASA Astrophysics Data System (ADS)

    Itoh, Mitsunori; Maeda, Takenori; Kakikura, Akihito; Kaneko, Yudai; Mori, Kazuhiro; Nakashima, Takuji; Wakita, Masashi; Uematsu, Tsutomu; Totani, Tsuyoshi; Oshima, Nobuyuki; Nagata, Harunori

    A series of lab-scale firing tests was conducted to investigate the fuel regression characteristics of Cascaded Multistage Impinging-jet (CAMUI) type hybrid rocket. The alternative fuel grain used in this rocket consists of a number of cylindrical fuel blocks with two ports, which were aligned along the axis of the combustion chamber with a small gap. The ports are aligned staggered with respect to ones of neighboring blocks so that the combustion gas flow impinges on the forward-end surface of each block. In this fuel grain, forward-end surfaces, back-end surfaces and ports of fuel blocks contribute as burning surfaces. Polyethylene and LOX were used as a propellant, and the tests were conducted at the chamber pressure of 0.5 2MPa and the mass flux of 50 200kg/m2s. Main results obtained in this study are in the followings: The regression rate of each surface was obtained as a function of the propellant mass flux and local equivalent ratio of the combustion gas. At back-end surfaces the regression rate has a high sensitivity on the gap height of neighboring fuel blocks. These fuel regression characteristics will contribute as fundamental data to improve the optimum design of the fuel grain.

  5. Response to actual and simulated recordings of conventional takeoff and landing jet aircraft

    NASA Technical Reports Server (NTRS)

    Mabry, J. E.; Sullivan, B. M.

    1978-01-01

    Comparability between noise characteristics of synthesized recordings of aircraft in flight and actual recordings were investigated. Although the synthesized recordings were more smoothly time-varying than the actual recordings and the synthesizer could not produce a comb-filter effect that was present in the actual recordings, results supported the conclusion that annoyance response is comparable to the synthesized and actual recordings. A correction for duration markedly improved the validity of engineering calculation procedures designed to measure noise annoyance. Results led to the conclusion that the magnitude estimation psychophysical method was a highly reliable approach for evaluating engineering calculation procedures designed to measure noise annoyance. For repeated presentations of pairs of actual recordings, differences between judgment results for identical signals ranged from 0.0 to 0.5 db.

  6. 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.

  7. Noise and static performance characteristics of a STOL aircraft jet flap

    NASA Technical Reports Server (NTRS)

    Harkonen, D. L.; Mcbride, J. F.; Okeefe, J. V.

    1974-01-01

    Static noise and performance tests were conducted on a 1/4-scale jet flap model with a multilobe nozzle of array area ratio of 2.7. The model nozzle and flap tested were a two-dimensional section of a distributed blowing system similar to previously investigated augmentor wing systems without the upper shroud and intake door. Noise data were measured with the nozzle alone and also during attached flow conditions with the flap at two turning angles representing takeoff and approach conditions. The noise data are scaled to a 200,000-lb TOGW four-engine airplane and are presented in terms of perceived noise level and one-third octave band sound pressure level. Comparisons are made with the noise levels produced by an augmentor wing airplane fitted with a three-element acoustically lined augmentor flap. The static performance is presented in terms of thrust recovery and effective turning angle.

  8. From lignin to cycloparaffins and aromatics: directional synthesis of jet and diesel fuel range biofuels using biomass.

    PubMed

    Bi, Peiyan; Wang, Jicong; Zhang, Yajing; Jiang, Peiwen; Wu, Xiaoping; Liu, Junxu; Xue, He; Wang, Tiejun; Li, Quanxin

    2015-05-01

    The continual growth in commercial aviation fuels and more strict environmental legislations have led to immense interest in developing green aviation fuels from biomass. This paper demonstrated a controllable transformation of lignin into jet and diesel fuel range hydrocarbons, involving directional production of C8-C15 aromatics by the catalytic depolymerization of lignin into C6-C8 low carbon aromatic monomers coupled with the alkylation of aromatics, and the directional production of C8-C15 cycloparaffins by the hydrogenation of aromatics. The key step, the production of the desired C8-C15 aromatics with the selectivity up to 94.3%, was achieved by the low temperature alkylation reactions of the lignin-derived monomers using ionic liquid. The synthetic biofuels basically met the main technical requirements of conventional jet fuels. The transformation potentially provides a useful way for the development of cycloparaffinic and aromatic components in jet fuels using renewable lignocellulose biomass. PMID:25710678

  9. From lignin to cycloparaffins and aromatics: directional synthesis of jet and diesel fuel range biofuels using biomass.

    PubMed

    Bi, Peiyan; Wang, Jicong; Zhang, Yajing; Jiang, Peiwen; Wu, Xiaoping; Liu, Junxu; Xue, He; Wang, Tiejun; Li, Quanxin

    2015-05-01

    The continual growth in commercial aviation fuels and more strict environmental legislations have led to immense interest in developing green aviation fuels from biomass. This paper demonstrated a controllable transformation of lignin into jet and diesel fuel range hydrocarbons, involving directional production of C8-C15 aromatics by the catalytic depolymerization of lignin into C6-C8 low carbon aromatic monomers coupled with the alkylation of aromatics, and the directional production of C8-C15 cycloparaffins by the hydrogenation of aromatics. The key step, the production of the desired C8-C15 aromatics with the selectivity up to 94.3%, was achieved by the low temperature alkylation reactions of the lignin-derived monomers using ionic liquid. The synthetic biofuels basically met the main technical requirements of conventional jet fuels. The transformation potentially provides a useful way for the development of cycloparaffinic and aromatic components in jet fuels using renewable lignocellulose biomass.

  10. Jet shielding of jet noise

    NASA Technical Reports Server (NTRS)

    Simonich, J. C.; Amiet, R. K.; Schlinker, R. H.

    1986-01-01

    An experimental and theoretical study was conducted to develop a validated first principle analysis for predicting the jet noise reduction achieved by shielding one jet exhaust flow with a second, closely spaced, identical jet flow. A generalized fuel jet noise analytical model was formulated in which the acoustic radiation from a source jet propagates through the velocity and temperature discontinuity of the adjacent shielding jet. Input variables to the prediction procedure include jet Mach number, spacing, temperature, diameter, and source frequency. Refraction, diffraction, and reflection effects, which control the dual jet directivity pattern, are incorporated in the theory. The analysis calculates the difference in sound pressure level between the dual jet configuration and the radiation field based on superimposing two independent jet noise directivity patterns. Jet shielding was found experimentally to reduce noise levels in the common plane of the dual jet system relative to the noise generated by two independent jets.

  11. Measurement and characterization of fully transient diesel fuel jet processes in an optical engine with production injectors

    NASA Astrophysics Data System (ADS)

    Neal, Nicholas; Rothamer, David

    2016-10-01

    The effects of transient rate-of-injection profiles on high-pressure diesel fuel jets have been studied in an optically accessible internal combustion engine. High-speed optical imaging measurements were applied over a range of ambient conditions, fuel types, and injection parameters. This paper demonstrates that during the early part of the injection, while the liquid core is disintegrating, the penetration is functionally linked to the inviscid orifice exit velocity up until a downstream distance hypothesized to be the jet breakup length. The jets then transitioned to a mixing dominated penetration behavior afterward. Therefore, for cases that exhibit transient rate-of-injection profiles, quasi-steady penetration analytical solutions for penetration have poor agreement with the empirical data. The development of an adaptive edgefinding algorithm for accurately detecting jets in engines is detailed. These findings indicate that empirical correlations widely used throughout the engine community for estimating jet penetration do not accurately represent actual injection parameters under transient conditions.

  12. Preliminary Analysis of the Effect of Flow Separation Due to Rocket Jet Pluming on Aircraft Dynamic Stability During Atmospheric Exit

    NASA Technical Reports Server (NTRS)

    Dryer, Murray; North, Warren J.

    1959-01-01

    A theoretical investigation was conducted to determine the effects of body boundary-layer separation resulting from a highly underexpanded jet on the dynamic stability of a typical rocket aircraft during an atmospheric exit trajectory. The particular flight condition studied on a digital computer for five degrees of freedom was at Mach 6.0 and 150,000 feet. In view of the unknown character of the separated flow field, two estimates of the pressures in the separated region were made to calculate the unbalanced forces and moments. These estimates, based on limited fundamental zero-angle-of-attack studies and observations, are believed to cover what may be the actual case. In addition to a fixed control case, two simulated pilot control inputs were studied: rate-limited and instantaneous responses. The resulting-motions with and without boundary-layer separation were compared for various initial conditions. The lower of the assumed misalinement forces and moments led to a situation whereby a slowly damped motion could be satisfactorily controlled with rate-limited control input. The higher assumption led to larger amplitude, divergent motions when the same control rates were used. These motions were damped only when the instantaneous control responses were assumed.

  13. Binder Jetting: A Novel Solid Oxide Fuel-Cell Fabrication Process and Evaluation

    NASA Astrophysics Data System (ADS)

    Manogharan, Guha; Kioko, Meshack; Linkous, Clovis

    2015-03-01

    With an ever-growing concern to find a more efficient and less polluting means of producing electricity, fuel cells have constantly been of great interest. Fuel cells electrochemically convert chemical energy directly into electricity and heat without resorting to combustion/mechanical cycling. This article studies the solid oxide fuel cell (SOFC), which is a high-temperature (100°C to 1000°C) ceramic cell made from all solid-state components and can operate under a wide range of fuel sources such as hydrogen, methanol, gasoline, diesel, and gasified coal. Traditionally, SOFCs are fabricated using processes such as tape casting, calendaring, extrusion, and warm pressing for substrate support, followed by screen printing, slurry coating, spray techniques, vapor deposition, and sputter techniques, which have limited control in substrate microstructure. In this article, the feasibility of engineering the porosity and configuration of an SOFC via an additive manufacturing (AM) method known as binder jet printing was explored. The anode, cathode and oxygen ion-conducting electrolyte layers were fabricated through AM sequentially as a complete fuel cell unit. The cell performance was measured in two modes: (I) as an electrolytic oxygen pump and (II) as a galvanic electricity generator using hydrogen gas as the fuel. An analysis on influence of porosity was performed through SEM studies and permeability testing. An additional study on fuel cell material composition was conducted to verify the effects of binder jetting through SEM-EDS. Electrical discharge of the AM fabricated SOFC and nonlinearity of permeability tests show that, with additional work, the porosity of the cell can be modified for optimal performance at operating flow and temperature conditions.

  14. A Nonlinear Fuel Optimal Reaction Jet Control Law

    SciTech Connect

    Breitfeller, E.; Ng, L.C.

    2002-06-30

    We derive a nonlinear fuel optimal attitude control system (ACS) that drives the final state to the desired state according to a cost function that weights the final state angular error relative to the angular rate error. Control is achieved by allowing the pulse-width-modulated (PWM) commands to begin and end anywhere within a control cycle, achieving a pulse width pulse time (PWPT) control. We show through a MATLAB{reg_sign} Simulink model that this steady-state condition may be accomplished, in the absence of sensor noise or model uncertainties, with the theoretical minimum number of actuator cycles. The ability to analytically achieve near-zero drift rates is particularly important in applications such as station-keeping and sensor imaging. Consideration is also given to the fact that, for relatively small sensor and model errors, the controller requires significantly fewer actuator cycles to reach the final state error than a traditional proportional-integral-derivative (PID) controller. The optimal PWPT attitude controller may be applicable for a high performance kinetic energy kill vehicle.

  15. VOC and hazardous air pollutant emission factors for military aircraft fuel cell inspection, maintenance, and repair operations

    SciTech Connect

    Nand, K.; Sahu, R.

    1997-12-31

    Accurate emission estimation is one of the key aspects of implementation of any air quality program. The Federal Title 5 program, specially requires an accurate and updated inventory of criteria as well hazardous air pollutants (HAPs) from all facilities. An overestimation of these two categories of pollutants, may cause the facility to be classified as a major source, when in fact it may actually be a minor source, and may also trigger unnecessary compliance requirements. A good example of where overestimation of volatile organic compounds (VOCs) and HAPs is easily possible are military aircraft fuel cells inspection, maintenance, and repair operations. The military aircraft fuel tanks, which are commonly identified as fuel cells, are routinely inspected for maintenance and repairs at military aircraft handling facilities. Prior to entry into the fuel cell by an inspector, fuel cells are first drained into bowsers and then purged with fresh air; the purged air is generally released without any controls to the atmosphere through a stack. The VOC and HAPs emission factors from these operations are not available in the literature for JP-8 fuel, which is being used increasingly by military aircraft. This paper presents two methods for estimating emissions for this source type, which are based on engineering calculations and professional judgment. This paper presents several methods for estimating emissions for this source type, which are based on engineering calculations and professional judgment. There are three emission producing phases during the draining and purging operations: (1) emissions during splash loading of bowsers (unloading of fuel cells), (2) emissions from spillage of fuel during loading of bowsers, and (3) emissions from fuel cell purging operations. Results of the emission estimation, including a comparison of the two emission estimation methods are presented in this paper.

  16. A reexamination of the formation of exhaust condensation trails by jet aircraft

    SciTech Connect

    Hanson, H.M.; Hanson, D.M.

    1995-11-01

    With the end of World War II, it became apparent that a study should be undertaken to identify the factors controlling the production of aircraft condensation trails (contrails). This early work provided a theoretical prediction of T{sub c}, the critical temperature at which the values of the relative humidity and pressure are such that the formation of the contrail phenomenon will occur. As empirical data were obtained, the general agreement at increased altitude was not precise and several studies were made to obtain both theoretical and empirical fits that would provide a {open_quotes}yes/no{close_quotes} decision. These modifications did allow a better decision for the formation of contrails but were found to be increasingly inaccurate at greater altitudes. This study provides an improved algorithm that yields a theoretical prediction that is in general agreement with the available empirical data at all altitudes. It demonstrates that there is a need for additional effort in the identification and precision of relative humidity and pressure that are input to this computation. 7 refs., 3 figs.

  17. The swelling of nitrile rubber by selected species in a synthetic jet turbine fuel

    NASA Astrophysics Data System (ADS)

    Graham, John Lynn

    The swelling of nitrile O-ring seals in petroleum distillate fuels has long been attributed to the aromatic species in these fuels. This presents a problem for synthetic fuels as they typically do not contain these aromatic species and thus may cause O-ring seals to shrink and fail. The composition of petroleum distillate fuels is extremely complex and it is not clear whether the swelling property originates from the aromatics in general, or if certain aromatics contribute more swelling character than others. Consequently, developing a general description of an efficient swelling promoter for O-rings in liquid hydrocarbon fuels will allow an unambiguous selection of candidate swelling agents for synthetic fuels. To accomplish this, a study was undertaken of the swelling of nitrile rubber (the most widely used O-ring material) in JP-5 (the jet propulsion fuel used by the U.S. Navy) and its synthetic equivalent S-5. Briefly, examining the molecular structure of nitrile rubber showed the fuel resistance of this polymer resides in the polar character of the cyano group suggesting that polar species in general, and hydrogen-bonded species in particular, should serve as efficient swelling promoters. A thorough test program utilizing a unique optical dilatometry method to provide temporal volume swell data, a GC-MS method for measuring the polymer/fuel partitioning, and a spectroscopic examination of thin nitrile rubber films confirmed this hypothesis. This program also showed that swelling character increases with decreasing molar volume which is consistent with previous work and general theories of solubility. Overall, this study showed that the most efficient aromatic swelling promoters for nitrile rubber are naphthalenes and asymmetrically substituted alkyl benzenes. However, polar species such as ketones and alcohols can be more efficient than aromatics while phenols and aromatic alcohols represent the most efficient potential swelling promoters for nitrile rubber in

  18. Life cycle assessment of camelina oil derived biodiesel and jet fuel in the Canadian Prairies.

    PubMed

    Li, Xue; Mupondwa, Edmund

    2014-05-15

    This study evaluated the environmental impact of biodiesel and hydroprocessed renewable jet fuel derived from camelina oil in terms of global warming potential, human health, ecosystem quality, and energy resource consumption. The life cycle inventory is based on production activities in the Canadian Prairies and encompasses activities ranging from agricultural production to oil extraction and fuel conversion. The system expansion method is used in this study to avoid allocation and to credit input energy to co-products associated with the products displaced in the market during camelina oil extraction and fuel processing. This is the preferred allocation method for LCA analysis in the context of most renewable and sustainable energy programs. The results show that greenhouse gas (GHG) emissions from 1 MJ of camelina derived biodiesel ranged from 7.61 to 24.72 g CO2 equivalent and 3.06 to 31.01 kg CO2/MJ equivalent for camelina HRJ fuel. Non-renewable energy consumption for camelina biodiesel ranged from 0.40 to 0.67 MJ/MJ; HRJ fuel ranged from -0.13 to 0.52 MJ/MJ. Camelina oil as a feedstock for fuel production accounted for the highest contribution to overall environmental performance, demonstrating the importance of reducing environmental burdens during the agricultural production process. Attaining higher seed yield would dramatically lower environmental impacts associated with camelina seed, oil, and fuel production. The lower GHG emissions and energy consumption associated with camelina in comparison with other oilseed derived fuel and petroleum fuel make camelina derived fuel from Canadian Prairies environmentally attractive. PMID:24572928

  19. Life cycle assessment of camelina oil derived biodiesel and jet fuel in the Canadian Prairies.

    PubMed

    Li, Xue; Mupondwa, Edmund

    2014-05-15

    This study evaluated the environmental impact of biodiesel and hydroprocessed renewable jet fuel derived from camelina oil in terms of global warming potential, human health, ecosystem quality, and energy resource consumption. The life cycle inventory is based on production activities in the Canadian Prairies and encompasses activities ranging from agricultural production to oil extraction and fuel conversion. The system expansion method is used in this study to avoid allocation and to credit input energy to co-products associated with the products displaced in the market during camelina oil extraction and fuel processing. This is the preferred allocation method for LCA analysis in the context of most renewable and sustainable energy programs. The results show that greenhouse gas (GHG) emissions from 1 MJ of camelina derived biodiesel ranged from 7.61 to 24.72 g CO2 equivalent and 3.06 to 31.01 kg CO2/MJ equivalent for camelina HRJ fuel. Non-renewable energy consumption for camelina biodiesel ranged from 0.40 to 0.67 MJ/MJ; HRJ fuel ranged from -0.13 to 0.52 MJ/MJ. Camelina oil as a feedstock for fuel production accounted for the highest contribution to overall environmental performance, demonstrating the importance of reducing environmental burdens during the agricultural production process. Attaining higher seed yield would dramatically lower environmental impacts associated with camelina seed, oil, and fuel production. The lower GHG emissions and energy consumption associated with camelina in comparison with other oilseed derived fuel and petroleum fuel make camelina derived fuel from Canadian Prairies environmentally attractive.

  20. Cryogenic and Simulated Fuel Jet Breakup in Argon, Helium and Nitrogen Gas Flows

    NASA Technical Reports Server (NTRS)

    Ingebo, Robert D.

    1995-01-01

    Two-phase flow atomization of liquid nitrogen jets was experimentally investigated. They were co-axially injected into high-velocity gas flows of helium, nitrogen and argon, respectively, and atomized internally inside a two-fluid fuel nozzle. Cryogenic sprays with relatively high specific surface areas were produced, i.e., ratios of surface area to volume were fairly high. This was indicated by values of reciprocal Sauter mean diameters, RSMD's, as measured with a scattered- light scanning instrument developed at NASA Lewis Research Center. Correlating expressions were derived for the three atomizing gases over a gas temperature range of 111 to 422 K. Also, the correlation was extended to include waterjet breakup data that had been previously obtained in simulating fuel jet breakup in sonic velocity gas flow. The final correlating expression included a new dimensionless molecular-scale acceleration group. It was needed to correlate RSMD data, for LN2 and H2O sprays, with the fluid properties of the liquid jets and atomizing gases used in this investigation.

  1. Flight test experience and controlled impact of a remotely piloted jet transport aircraft

    NASA Technical Reports Server (NTRS)

    Horton, Timothy W.; Kempel, Robert W.

    1988-01-01

    The Dryden Flight Research Center Facility of NASA Ames Research Center (Ames-Dryden) and the FAA conducted the controlled impact demonstration (CID) program using a large, four-engine, remotely piloted jet transport airplane. Closed-loop primary flight was controlled through the existing onboard PB-20D autopilot which had been modified for the CID program. Uplink commands were sent from a ground-based cockpit and digital computer in conjunction with an up-down telemetry link. These uplink commands were received aboard the airplane and transferred through uplink interface systems to the modified PB-20D autopilot. Both proportional and discrete commands were produced by the ground system. Prior to flight tests, extensive simulation was conducted during the development of ground-based digital control laws. The control laws included primary control, secondary control, and racetrack and final approach guidance. Extensive ground checks were performed on all remotely piloted systems; however, piloted flight tests were the primary method and validation of control law concepts developed from simulation. The design, development, and flight testing of control laws and systems required to accomplish the remotely piloted mission are discussed.

  2. Refinery Integration of By-Products from Coal-Derived Jet Fuels

    SciTech Connect

    Leslie R. Rudnick; Andre Boehman; Chunshan Song; Bruce Miller; Gareth Mitchell

    2005-11-17

    This report summarizes the accomplishments toward project goals during the first six months of the second year of the project to assess the properties and performance of coal based products. These products are in the gasoline, diesel and fuel oil range and result from coal based jet fuel production from an Air Force funded program. Specific areas of progress include generation of coal based material that has been fractionated into the desired refinery cuts, acquisition and installation of a research gasoline engine, and modification of diesel engines for use in evaluating diesel produced in the project. The desulfurization of sulfur containing components of coal and petroleum is being studied so that effective conversion of blended coal and petroleum streams can be efficiently converted to useful refinery products. Evaluations to assess the quality of coal based fuel oil are reported. Coal samples have procured and are being assessed for cleaning prior to use in coking studies.

  3. Advanced thermally stable jet fuels. Technical progress report, January 1995--March 1995

    SciTech Connect

    Schobert, H.H.; Eser, S.; Song, C.

    1995-06-01

    Quantitative structure-property relationships have been applied to study the thermal stability of pure hydrocarbons typical of jet fuel components. A simple method of chemical structure description in terms of Benson groups was tested in searching for structure-property relationships for the hydrocarbons tested experimentally in this program. Molecular connectivity as a structure-based approach to chemical structure-property relationship analysis was also tested. Further development of both the experimental data base and computational methods will be necessary. Thermal decomposition studies, using glass tube reactors, were extended to two additional model compounds: n-decane and n-dodecane. Efforts on refining the deposit growth measurement and characterization of suspended matter in stressed fuels have lead to improvements in the analysis of stressed fuels. Catalytic hydrogenation and dehydrogenation studies utilizing a molybdenum sulfide catalyst are also described.

  4. Pollution Reduction Technology Program for Small Jet Aircraft Engines, Phase 2

    NASA Technical Reports Server (NTRS)

    Bruce, T. W.; Davis, F. G.; Kuhn, T. E.; Mongia, H. C.

    1978-01-01

    A series of iterative combustor pressure rig tests were conducted on two combustor concepts applied to the AiResearch TFE731-2 turbofan engine combustion system for the purpose of optimizing combustor performance and operating characteristics consistant with low emissions. The two concepts were an axial air-assisted airblast fuel injection configuration with variable-geometry air swirlers and a staged premix/prevaporization configuration. The iterative rig testing and modification sequence on both concepts was intended to provide operational compatibility with the engine and determine one concept for further evaluation in a TFE731-2 engine.

  5. Comparison of several Brassica species in the north central U.S. for potential jet fuel feedstock

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hydrotreated renewable jet fuel (HRJ) derived from crop oils has been commercially demonstrated but full-scale production has been hindered by feedstock costs that make the product more costly than petroleum-based fuels. Maintaining low feedstock costs while developing crops attractive to farmers to...

  6. Agronomic comparison of several brassica species in the U.S. Corn Belt as feedstock for hydrotreated jet fuel

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Through a patented process developed in the U.S., hydrotreated renewable jet fuel (HRJ) derived from plant oils has been commercially demonstrated. However, full-scale production has not yet come to fruition because HRJ is not economically competitive with petroleum-based fuels due to high feedstock...

  7. 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.

  8. Lubricity of well-characterized jet and broad-cut fuels by ball-on-cylinder machine

    NASA Technical Reports Server (NTRS)

    Prok, G. M.; Kim, W. S.

    1984-01-01

    A ball-on-cylinder machine (BOCM) was used to measure the lubricity of fuels. The fuels tested were well-characterized fuels available from other programs at the NASA Lewis Research Center plus some in-house mildly hydroprocessed shale fuels from other programs included Jet-A, ERBS fuel, ERBS blends, and blend stock. The BOCM tests were made before and after clay treatment of some of these fuels with both humidified air and dry nitrogen as the preconditioning and cover gas. As expected, clay treatment always reduced fuel lubricity. Using nitrogen preconditioning and cover gas always resulted in a smaller wear scar diameter than when humidified air was used. Also observed was an indication of lower lubricity with lower boiling range fuels and lower aromatic fuels. Gas chromatographic analysis indicted changes in BOCM-stressed fuels.

  9. Topical absorption and toxicity studies of jet fuel hydrocarbons in skin

    NASA Astrophysics Data System (ADS)

    Muhammad, Faqir

    Kerosene-based fuels have been used for many decades. Over 2 million military and civilian personnel each year are occupationally exposed to various jet fuel mixtures. Dermatitis is one of the major health concerns associated with these exposures. In the past, separate absorption and toxicity studies have been conducted to find the etiology of such skin disorders. There was a need for integrated absorption and toxicity studies to define the causative constituents of jet fuel responsible for skin irritation. The focus of this thesis was to study the percutaneous absorption and to identify the hydrocarbons (HC) causing irritation in jet fuels so that preventive measures could be taken in the future. The initial study was conducted to understand the possible mechanism for additive interactions on hydrocarbon absorption/disposition in silastic, porcine skin and isolated perfused porcine skin flap (IPPSF) models. The influence of JP-8 (100) additives (MDA, BHT, 8Q405) on the dermal kinetics of 14C-naphthalene and 14C/3H-dodecane as markers of HC absorption was evaluated. This study indicated that individual and combination of additives influenced marker disposition in different membranes. MDA was a significant suppressor while BHT was a significant enhancer of naphthalene absorption in IPPSF. The 8Q405 significantly reduced naphthalene content in dosed silastic and skin indicating a direct interaction between additive and marker HC. Similarly, the individual MDA and BHT significantly retained naphthalene in the stratum corneum of porcine skin, but the combination of both of these additives statistically decreased the marker retention in the stratum corneum suggesting a potential biological interaction. This study concluded that all components of a chemical mixture should be assessed since the effects of single components administered alone or as pairs may be confounded when all are present in the complete mixture. However, this study indicated that the marker HC

  10. Characterization of Synthetic GTL Jet Fuel for use in Gas Turbine Engines

    NASA Astrophysics Data System (ADS)

    Sadr, Reza; Kannaiyan, Kumaran

    2010-11-01

    Stringent emission regulations have instigated the search for alternative-clean source of energy. Recently, Gas-to-Liquid (GTL) fuel has grabbed the global attention by its clean combustion characteristics owing to the absence of aromatics and Sulphur. However, this will introduce potential risks and benefits. Last fall Qatar airways has proven the feasibility of using GTL as a potential alternative clean fuel by a 3200 mile flight using a fuel blend of 50% JetA + 50% GTL. Researchers from Texas A & M University at Qatar (TAMUQ) in collaboration with their counterparts in Rolls-Royce (RR), UK, and German Aerospace Laboratory (DLR) are in a joint effort to establish an in-depth characterization of the combustion performance of GTL fuel in gas turbine engines. In TAMUQ, the research focus is to investigate the spray characteristics of GTL fuels. The results will be compared with that of standard fuel and correlate with combustion results to gain insights on GTL performance. This will help designers to optimize the nozzle geometry to improve the combustor performance. The objective of this talk is to introduce this ongoing effort and to discuss the experimental facility and preliminary results.

  11. Protozoa in Subsurface Sediments from Sites Contaminated with Aviation Gasoline or Jet Fuel

    PubMed Central

    Sinclair, James L.; Kampbell, Don H.; Cook, Mike L.; Wilson, John T.

    1993-01-01

    Numbers of protozoa in the subsurface of aviation gasoline and jet fuel spill areas at a Coast Guard base at Traverse City, Mich., were determined. Boreholes were drilled in an uncontaminated location, in contaminated but untreated parts of the fuel plumes, and in the aviation gasoline source area undergoing H2O2 biotreatment. Samples were taken from the unsaturated zone to depths slightly below the floating free product in the saturated zone. Protozoa were found to occur in elevated numbers in the unsaturated zone, where fuel vapors mixed with atmospheric oxygen, and below the layer of floating fuel, where uncontaminated groundwater came into contact with fuel. The same trends were noted in the biotreatment area, except that numbers of protozoa were higher. Numbers of protozoa in some contaminated areas equalled or exceeded those found in surface soil. The abundance of protozoa in the biotreatment area was high enough that it would be expected to significantly reduce the bacterial community that was degrading the fuel. Little reduction in hydraulic conductivity was observed, and no bacterial fouling of the aquifer was observed during biotreatment. PMID:16348871

  12. Protozoa in subsurface sediments from sites contaminated with aviation gasoline or jet fuel.

    PubMed

    Sinclair, J L; Kampbell, D H; Cook, M L; Wilson, J T

    1993-02-01

    Numbers of protozoa in the subsurface of aviation gasoline and jet fuel spill areas at a Coast Guard base at Traverse City, Mich., were determined. Boreholes were drilled in an uncontaminated location, in contaminated but untreated parts of the fuel plumes, and in the aviation gasoline source area undergoing H(2)O(2) biotreatment. Samples were taken from the unsaturated zone to depths slightly below the floating free product in the saturated zone. Protozoa were found to occur in elevated numbers in the unsaturated zone, where fuel vapors mixed with atmospheric oxygen, and below the layer of floating fuel, where uncontaminated groundwater came into contact with fuel. The same trends were noted in the biotreatment area, except that numbers of protozoa were higher. Numbers of protozoa in some contaminated areas equalled or exceeded those found in surface soil. The abundance of protozoa in the biotreatment area was high enough that it would be expected to significantly reduce the bacterial community that was degrading the fuel. Little reduction in hydraulic conductivity was observed, and no bacterial fouling of the aquifer was observed during biotreatment.

  13. Performance and emissions of a catalytic reactor with propane, diesel, and Jet A fuels

    NASA Technical Reports Server (NTRS)

    Anderson, D. N.

    1977-01-01

    Tests were made to determine the performance and emissions of a catalytic reactor operated with propane, No. 2 diesel, and Jet A fuels. A 12-cm diameter and 16-cm long catalytic reactor using a proprietary noble metal catalyst was operated at an inlet temperature of 800 K, a pressure of 300,000 Pa and reference velocities of 10 to 15 m/s. No significant differences between the performance of the three fuels were observed when 98.5 percent purity propane was used. The combustion efficiency for 99.8-percent purity propane tested later was significantly lower, however. The diesel fuel contained 135 ppm of bound nitrogen and consequently produced the highest NOx emissions of the three fuels. As much as 85 percent of the bound nitrogen was converted to NOx. Steady-state emissions goals based on half the most stringent proposed automotive standards were met when the reactor was operated at an adiabatic combustion temperature higher than 1350 K with all fuels except the 99.8-percent purity propane. With that fuel, a minimum temperature of 1480 K was required.

  14. A study to estimate and compare the total particulate matter emission indices (EIN) between traditional jet fuel and two blends of Jet A/Camelina biofuel used in a high by-pass turbofan engine: A case study of Honeywell TFE-109 engine

    NASA Astrophysics Data System (ADS)

    Shila, Jacob Joshua Howard

    The aviation industry is expected to grow at an annual rate of 5% until the year 2031 according to Boeing Outlook Report of 2012. Although the aerospace manufacturers have introduced new aircraft and engines technologies to reduce the emissions generated by aircraft engines, about 15% of all aircraft in 2032 will be using the older technologies. Therefore, agencies such as the National Aeronautics and Astronautics Administration (NASA), Federal Aviation Administration (FAA), the Environmental Protection Agency (EPA) among others together with some academic institutions have been working to characterize both physical and chemical characteristics of the aircraft particulate matter emissions to further understand their effects to the environment. The International Civil Aviation Organization (ICAO) is also working to establish an inventory with Particulate Matter emissions for all the aircraft turbine engines for certification purposes. This steps comes as a result of smoke measurements not being sufficient to provide detailed information on the effects of Particulate Matter (PM) emissions as far as the health and environmental concerns. The use of alternative fuels is essential to reduce the impacts of emissions released by Jet engines since alternative aviation fuels have been studied to lower particulate matter emissions in some types of engines families. The purpose of this study was to determine whether the emission indices of the biofuel blended fuels were lower than the emission indices of the traditional jet fuel at selected engine thrust settings. The biofuel blends observed were 75% Jet A-25% Camelina blend biofuel, and 50% Jet A-50% Jet A blend biofuel. The traditional jet fuel in this study was the Jet A fuel. The results of this study may be useful in establishing a baseline for aircraft engines' PM inventory. Currently the International Civil Aviation Organization (ICAO) engines emissions database contains only gaseous emissions data for only the TFE 731

  15. Pollution reduction technology program for small jet aircraft engines, phase 1

    NASA Technical Reports Server (NTRS)

    Bruce, T. W.; Davis, F. G.; Kuhn, T. E.; Mongia, H. C.

    1977-01-01

    A series of combustor pressure rig screening tests was conducted on three combustor concepts applied to the TFE731-2 turbofan engine combustion system for the purpose of evaluating their relative emissions reduction potential consistent with prescribed performance, durability, and envelope contraints. The three concepts and their modifications represented increasing potential for reducing emission levels with the penalty of increased hardware complexity and operational risk. Concept 1 entailed advanced modifications to the present production TFE731-2 combustion system. Concept 2 was based on the incorporation of an axial air-assisted airblast fuel injection system. Concept 3 was a staged premix/prevaporizing combustion system. Significant emissions reductions were achieved in all three concepts, consistent with acceptable combustion system performance. Concepts 2 and 3 were identified as having the greatest achievable emissions reduction potential, and were selected to undergo refinement to prepare for ultimate incorporation within an engine.

  16. Pulmonary Evaluation of Permissible Exposure Limit of Syntroleum S-8 Synthetic Jet Fuel in Mice

    PubMed Central

    Wong, Simon S.; Thomas, Alana; Barbaris, Brian; Lantz, R. Clark; Witten, Mark L.

    2009-01-01

    No current studies have systematically examined pulmonary health effects associated with Syntroleum S-8 synthetic jet fuel (S-8). In order to gain an understanding about the threshold concentration in which lung injury is observed, C57BL/6 male mice were nose-only exposed to S-8 for 1 h/day for 7 days at average concentrations of 0 (control), 93, 352, and 616 mg/m3. Evaluation of pulmonary function, airway epithelial barrier integrity, and pathohistology was performed 24 h after the final exposures. Significant decreases were detected in expiratory lung resistance and total lung compliance of the 352 mg/m3 group, for which no clear concentration-dependent alterations could be determined. No significant changes in respiratory permeability were exhibited, indicating that there was no loss of epithelial barrier integrity following S-8 exposure. However, morphological examination and morphometric analysis of distal lung tissue, by using transmission electron microscopy, revealed cellular damage in alveolar type II epithelial cells, with significant increases in volume density of lamellar bodies/vacuoles at 352 and 616 S-8 mg/m3. Moreover, terminal bronchiolar Clara injury, as evidenced by apical membrane blebs, was observed at relatively low concentrations, suggesting if this synthetic jet fuel is utilized, the current permissible exposure limit of 350 mg/m3 for hydrocarbon fuels should cautiously be applied. PMID:19357071

  17. Unitized regenerative fuel cells for solar rechargeable aircraft and zero emission vehicles

    SciTech Connect

    Mitlitsky, F.; Colella, N.J.; Myers, B.

    1994-09-06

    A unitized regenerative fuel cell (URFC) produces power and electrolytically regenerates its reactants using a single stack of reversible cells. URFCs have been designed for high altitude long endurance (HALE) solar rechargeable aircraft (SRA), zero emission vehicles (ZEVs), hybrid energy storage/propulsion systems for long duration satellites, energy storage for remote (off-grid) power sources, and peak shaving for on-grid applications. URFCs 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 ZEVs using hydrogen/air with oxygen supercharging. Overlapping and synergistic development and testing opportunities for these two technologies will be highlighted.

  18. Advanced thermally stable jet fuels. Technical progress report, July 1993--September 1993

    SciTech Connect

    Schobert, H.H.; Eser, S.; Song, C.; Hatcher, P.G.; Walsh, P.M.; Coleman, M.M.

    1993-12-01

    The Penn State program in advanced thermally stable coal-based jet fuels has five broad objectives: (1) development of mechanisms of degradation and solids formation; (2) quantitative measurement of growth of sub-micrometer and micrometer-sized particles suspended in fuels during thermal stressing; (3) characterization of carbonaceous deposits by various instrumental and microscopic methods; (4) elucidation of the role of additives in retarding the formation of carbonaceous solids; (5) assessment of the potential of production of high yields of cycloalkanes by direct liquefaction of coal. An exploratory study was conducted to investigate the pyrolysis of n-butylbenzene in a flow reactor at atmospheric pressure. A number of similarities to trends previously observed in high-pressure static reactions were identified. The product distribution from pyrolysis of n-tetradecane at 400{degrees}C and 425{degrees}C was investigated. The critical temperatures of a suite of petroleum- and coal-derived jet fuels were measured by a rapidly heating sealed tube method. Work has continued on refining the measurements of deposit growth for stressing mixtures of coal-derived JP-8C with tetradecane. Current work has given emphasis to the initial stages of fuel decomposition and the onset of deposition. Pretreatment of JPTS fuel with PX-21 activated carbon (50 mg of PX-21 in 15 mL JPTS) delayed degradation and prevented carbon deposition during thermal stressing at 425{degrees}C for 5 h in nitrogen and air atmospheres. Clear indications of initial and subsequent deposit formation on different metal surfaces have been identified for thermal stressing of dodecane. Seven additives were tested for their ability to retard decomposition of dodecane at 450{degrees}C under nitrogen. Nuclear magnetic resonance data for Dammar resin indicates that structures proposed in the literature are not entirely correct.

  19. Effects of JP-8 Jet Fuel on Homeostasis of Clone 9 Rat Liver Cells

    NASA Technical Reports Server (NTRS)

    Wilson, C. L.; Barhoumi, R.; Burghardt, R.; Miladi, A.; Jung, A.

    2000-01-01

    Chronic exposure to JP-8 and other kerosene-based petroleum distillates has been associated with hepatic, renal, neurologic, pulmonary, and immune toxicity. However, the effects of kerosene-type jet fuels on cellular homeostasis hitherto have not been reported. Fluorescence imaging using a Meridian Ultima laser scanning fluorescence microscope was used to evaluate the effect of JP-8 jet fuel on a communication competent rat liver cell line. Several endpoints of cellular function were measured including gap junctional intercellular communication (GJIC), mitochondrial and plasma membrane potential (MMP and PMP, respectively), intracellular glutathione (GSH) concentration, glutathione-S-transferase (GST) activity, and reactive oxygen species (ROS) generation. Cells were treated with JP-8 (0.01 to 2% in ethanol (EtOH)) for the following time points: 1 h, 24 h, 48 h, and analysis immediately after addition of jet fuel. GJIC analyzed directly after addition of 1% JP-8 was reduced 4.9-fold relative to EtOH-dosed control groups and further reduction (12.6-fold) was observed in cells treated for 1 h. Moreover, GJIC was not recoverable in cells treated with 1% JP-8 for 1 h and subsequently washed and incubated in fresh medium for 1 h. Significant changes in GSH content and GST activity were observed in cells analyzed directly after addition of 1% JP-8. GSH content increased in cells treated for 1 h with less than 2% JP-8 whereas treatment with 2% JP-8 for 1 h resulted in a 50% reduction in intracellular GSH relative to EtOH-dosed controls. Cells treated with 1% JP-8 for 48 h exhibited changes in GSH levels. However, higher JP-8 concentrations exhibited more pronounced changes in GSH and GST, which led to suppression of GSH synthesis. ROS increased in a dose-responsive fashion at JP-8 concentrations up to 1%, but decreased to 80% of control values at 2% and 3% JP-8. A 25% reduction in PMP was observed in cells treated for 1 h with 1% JP-8. In contrast, cells treated for 48 h

  20. Phenomenological study of the behavior of some silica formers in a high velocity jet fuel burner

    NASA Technical Reports Server (NTRS)

    Cawley, J. D.; Handschuh, R. F.

    1985-01-01

    Samples of four silica formers: single crystal SiC, sintered alpha-SiC, reaction sintered Si3N4 and polycrystalline MoSi2, were subjected to a Mach 1 jet fuel burner for 1 hr, at a sample temperature of 1375 deg C (2500 deg F). Two phenomena were identified which may be deleterious to a gas turbine application of these materials. The glass layer formed on the MoSi2 deformed appreciably under the aerodynamic load. A scale developed on the samples of the other materials which consisted of particular matter from the gas stream entrapped in a SiO2 matrix.

  1. Relationship between ignition processes and the lift-off length of diesel fuel jets.

    SciTech Connect

    Siebers, Dennis L.; Idicheria, Cherian A.; Pickett, Lyle M.

    2005-06-01

    The reaction zone of a diesel fuel jet stabilizes at a location downstream of the fuel injector once the initial autoignition phase is over. This distance is referred to as flame lift-off length. Recent investigations have examined the effects of a wide range of parameters (injection pressure, orifice diameter, and ambient gas temperature, density and oxygen concentration) on lift-off length under quiescent diesel conditions. Many of the experimental trends in lift-off length were in agreement with scaling laws developed for turbulent, premixed flame propagation in gas-jet lifted flames at atmospheric conditions. However, several effects did not correlate with the gas-jet scaling laws, suggesting that other mechanisms could be important to lift-off stabilization at diesel conditions. This paper shows experimental evidence that ignition processes affect diesel lift-off stabilization. Experiments were performed in the same optically-accessible combustion vessel as the previous lift-off research. The experimental results show that the ignition quality of a fuel affects lift-off. Fuels with shorter ignition delays generally produce shorter lift-off lengths. In addition, a cool flame is found upstream of, or near the same axial location as, the quasi-steady lift-off length, indicating that first-stage ignition processes affect lift-off. High-speed chemiluminescence imaging also shows that high-temperature self-ignition occasionally occurs in kernels that are upstream of, and detached from, the high-temperature reaction zone downstream, suggesting that the lift-off stabilization is not by flame propagation into upstream reactants in this instance. Finally, analysis of the previous lift-off length database shows that the time-scale for jet mixing from injector-tip orifice to lift-off length collapses to an Arrhenius-type expression, a common method for describing ignition delay in diesel sprays. This Arrhenius-based lift-off length correlation shows comparable accuracy as

  2. Advanced air transport concepts. [review of design methods for very large aircraft

    NASA Technical Reports Server (NTRS)

    Molloy, J. K.

    1979-01-01

    The concepts of laminar flow control, very large all-wing aircraft, an aerial relay transportation system and alternative fuels, which would enable large improvements in fuel conservation in air transportation in the 1990's are discussed. Laminar boundary layer control through suction would greatly reduce skin friction and has been reported to reduce fuel consumption by up to 29%. Distributed load aircraft, in which all fuel and payload are carried in the wing and the fuselage is absent, permit the use of lighter construction materials and the elimination of fuselage and tail drag. Spanloader aircraft with laminar flow control could be used in an aerial relay transportation system which would employ a network of continuously flying liners supplied with fuel, cargo and crews by smaller feeder aircraft. Liquid hydrogen and methane fuels derived from coal are shown to be more weight efficient and less costly than coal-derived synthetic jet fuels.

  3. Subtask 3.11 - Production of CBTL-Based Jet Fuels from Biomass-Based Feedstocks and Montana Coal

    SciTech Connect

    Sharma, Ramesh

    2014-06-01

    The Energy & Environmental Research Center (EERC), in partnership with the U.S. Department of Energy (DOE) and Accelergy Corporation, an advanced fuels developer with technologies exclusively licensed from Exxon Mobil, undertook Subtask 3.11 to use a recently installed bench-scale direct coal liquefaction (DCL) system capable of converting 45 pounds/hour of pulverized, dried coal to a liquid suitable for upgrading to fuels and/or chemicals. The process involves liquefaction of Rosebud mine coal (Montana coal) coupled with an upgrading scheme to produce a naphthenic fuel. The upgrading comprises catalytic hydrotreating and saturation to produce naphthenic fuel. A synthetic jet fuel was prepared by blending equal volumes of naphthenic fuel with similar aliphatic fuel derived from biomass and 11 volume % of aromatic hydrocarbons. The synthetic fuel was tested using standard ASTM International techniques to determine compliance with JP-8 fuel. The composite fuel thus produced not only meets but exceeds the military aviation fuel-screening criteria. A 500-milliliter synthetic jet fuel sample which met internal screening criteria was submitted to the Air Force Research Laboratory (AFRL) at Wright–Patterson Air Force Base, Dayton, Ohio, for evaluation. The sample was confirmed by AFRL to be in compliance with U.S. Air Force-prescribed alternative aviation fuel initial screening criteria. The results show that this fuel meets or exceeds the key specification parameters for JP-8, a petroleum-based jet fuel widely used by the U.S. military. JP-8 specifications include parameters such as freeze point, density, flash point, and others; all of which were met by the EERC fuel sample. The fuel also exceeds the thermal stability specification of JP-8 fuel as determined by the quartz crystalline microbalance (QCM) test also performed at an independent laboratory as well as AFRL. This means that the EERC fuel looks and acts identically to petroleum-derived jet fuel and can be used

  4. 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

  5. Chemical Processing of Non-Crop Plants for Jet Fuel Blends Production

    NASA Technical Reports Server (NTRS)

    Kulis, M. J.; Hepp, A. F.; McDowell, M.; Ribita, D.

    2009-01-01

    The use of Biofuels has been gaining in popularity over the past few years due to their ability to reduce the dependence on fossil fuels. Biofuels as a renewable energy source can be a viable option for sustaining long-term energy needs if they are managed efficiently. We describe our initial efforts to exploit algae, halophytes and other non-crop plants to produce synthetics for fuel blends that can potentially be used as fuels for aviation and non-aerospace applications. Our efforts have been dedicated to crafting efficient extraction and refining processes in order to extract constituents from the plant materials with the ultimate goal of determining the feasibility of producing biomass-based jet fuel from the refined extract. Two extraction methods have been developed based on communition processes, and liquid-solid extraction techniques. Refining procedures such as chlorophyll removal and transesterification of triglycerides have been performed. Gas chromatography in tandem with mass spectroscopy is currently being utilized in order to qualitatively determine the individual components of the refined extract. We also briefly discuss and compare alternative methods to extract fuel-blending agents from alternative biofuels sources.

  6. 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.

  7. Reduction of gaseous pollutant emissions from gas turbine combustors using hydrogen-enriched jet fuel

    NASA Technical Reports Server (NTRS)

    Clayton, R. M.

    1976-01-01

    Recent progress in an evaluation of the applicability of the hydrogen enrichment concept to achieve ultralow gaseous pollutant emission from gas turbine combustion systems is described. The target emission indexes for the program are 1.0 for oxides of nitrogen and carbon monoxide, and 0.5 for unburned hydrocarbons. The basic concept utilizes premixed molecular hydrogen, conventional jet fuel, and air to depress the lean flammability limit of the mixed fuel. This is shown to permit very lean combustion with its low NOx production while simulataneously providing an increased flame stability margin with which to maintain low CO and HC emission. Experimental emission characteristics and selected analytical results are presented for a cylindrical research combustor designed for operation with inlet-air state conditions typical for a 30:1 compression ratio, high bypass ratio, turbofan commercial engine.

  8. Composition-explicit distillation curves of aviation fuel JP-8 and a coal-based jet fuel

    SciTech Connect

    Beverly L. Smith; Thomas J. Bruno

    2007-09-15

    We have recently introduced several important improvements in the measurement of distillation curves for complex fluids. The modifications to the classical measurement provide for (1) a composition explicit data channel for each distillate fraction (for both qualitative and quantitative analysis); (2) temperature measurements that are true thermodynamic state points; (3) temperature, volume, and pressure measurements of low uncertainty suitable for an equation of state development; (4) consistency with a century of historical data; (5) an assessment of the energy content of each distillate fraction; (6) a trace chemical analysis of each distillate fraction; and (7) a corrosivity assessment of each distillate fraction. The most significant modification is achieved with a new sampling approach that allows precise qualitative as well as quantitative analyses of each fraction, on the fly. We have applied the new method to the measurement of rocket propellant, gasoline, and jet fuels. In this paper, we present the application of the technique to representative batches of the military aviation fuel JP-8, and also to a coal-derived fuel developed as a potential substitute. We present not only the distillation curves but also a chemical characterization of each fraction and discuss the contrasts between the two fluids. 26 refs., 5 figs., 6 tabs.

  9. Development of an advanced pitch active control system and a reduced area horizontal tail for a wide-body jet aircraft

    NASA Technical Reports Server (NTRS)

    Guinn, Wiley A.

    1984-01-01

    The development of an advanced pitch active control system (PACS) and a reduced area horizontal tail for a wide-body jet transport (L-1011) with a flying horizontal stabilizer is discussed. The advanced PACS control law design objectives were to provide satisfactory handling qualities for aft c.g. flight conditions to negative static stability margins of 10 percent and to provide good maneuver control column force gradients for nonlinear stability flight conditions. Validity of the control laws were demonstrated by piloted flight simulation tests on the NASA Langley Visual Motion Simulator. Satisfactory handling qualities were actually demonstrated to a negative 20 percent static stability margin. The PACS control laws were mechanized to provide the system architecture that would be suitable for an L-1011 flight test program to a negative stability margin of 3 percent which represents the aft c.g. limits of the aircraft. Reduced area horizontal tail designs of 30 and 38 percent with respect to the L-1011 standard tail were designed, fabricated and wind tunnel tested. Drag reductions and weight savings of the 30 percent smaller tail would provide an L/D benefit of about 2% and the 38% small tail L/D benefit would be about 3 percent. However, forward c.g. limitations would have to be imposed on the aircraft because the maximum horizontal tail lift goal was not achieved and sufficient aircraft nose-up control authority was not available. This limitation would not be required for a properly designed new aircraft.

  10. Measurements of fuel mixture fraction oscillations of a turbulent jet non-premixed flame

    SciTech Connect

    Kanga, D.M.; Fernandez, V.; Culick, F.E.C.; Ratner, A.

    2009-01-15

    This work describes new type of combustion instability for which the 3-way coupling between mixing, flame heat release, and acoustics is modified by local buoyancy effects. Measurements of fuel mixture fraction are made for a non-premixed jet flame in a combustion chamber to assess the dynamics of mixing under imposed acoustic oscillations (22-55 Hz). Infrared laser absorption and phase resolved acetone-planar laser induced fluorescence are used to measure the fuel mixture fraction and then the degree of fuel/air mixing is calculated by determining the unmixedness. Results show acoustic excitation causes oscillations in the degree of fuel/air mixing at the driving frequency, which results in oscillatory flame behavior. This oscillatory flame behavior couples to the buoyancy and this in turn affects the mixing. Results also show that the mixing becomes less effective when the excitation frequency is increased or when the flame is present, compared to the non-reacting case. This work describes a key coupling mechanism that occurs when buoyancy is a significant factor in the flow field. (author)

  11. Metal organic chemical vapor deposition of environmental barrier coatings for the inhibition of solid deposit formation from heated jet fuel

    NASA Astrophysics Data System (ADS)

    Mohan, Arun Ram

    Solid deposit formation from jet fuel compromises the fuel handling system of an aviation turbine engine and increases the maintenance downtime of an aircraft. The deposit formation process depends upon the composition of the fuel, the nature of metal surfaces that come in contact with the heated fuel and the operating conditions of the engine. The objective of the study is to investigate the effect of substrate surfaces on the amount and nature of solid deposits in the intermediate regime where both autoxidation and pyrolysis play an important role in deposit formation. A particular focus has been directed to examining the effectiveness of barrier coatings produced by metal organic chemical vapor deposition (MOCVD) on metal surfaces for inhibiting the solid deposit formation from jet fuel degradation. In the first part of the experimental study, a commercial Jet-A sample was stressed in a flow reactor on seven different metal surfaces: AISI316, AISI 321, AISI 304, AISI 347, Inconel 600, Inconel 718, Inconel 750X and FecrAlloy. Examination of deposits by thermal and microscopic analysis shows that the solid deposit formation is influenced by the interaction of organosulfur compounds and autoxidation products with the metal surfaces. The nature of metal sulfides was predicted by Fe-Ni-S ternary phase diagram. Thermal stressing on uncoated surfaces produced coke deposits with varying degree of structural order. They are hydrogen-rich and structurally disordered deposits, spherulitic deposits, small carbon particles with relatively ordered structures and large platelets of ordered carbon structures formed by metal catalysis. In the second part of the study, environmental barrier coatings were deposited on tube surfaces to inhibit solid deposit formation from the heated fuel. A new CVD system was configured by the proper choice of components for mass flow, pressure and temperature control in the reactor. A bubbler was designed to deliver the precursor into the reactor

  12. IN-SITU AIR INJECTION, SOIL VACUUM EXTRACTION AND ENHANCED BIODEGRADATION: A CASE STUDY IN A JP-4 JET FUEL CONTAMINATED SITE

    EPA Science Inventory

    The U.S. Environmental Protection Agency (U.S. EPA) and the U.S. Coast Guard (USCG) conducted a joint demonstration of in situ remediation of a JP-4 jet fuel spill at the USCG Support Center in Elizabeth City, North Carolina. The jet fuel was trapped beneath a clay layer that ext...

  13. Spontaneous ignition in afterburner segment tests at an inlet temperature of 1240 K and a pressure of 1 atmosphere with ASTM jet-A fuel

    NASA Technical Reports Server (NTRS)

    Schultz, D. F.; Branstetter, J. R.

    1973-01-01

    A brief testing program was undertaken to determine if spontaneous ignition and stable combustion could be obtained in a jet engine afterburning operating with an inlet temperature of 1240 K and a pressure of 1 atmosphere with ASTM Jet-A fuel. Spontaneous ignition with 100-percent combustion efficiency and stable burning was obtained using water-cooled fuel spraybars as flameholders.

  14. Study of aircraft crashworthiness for fire protection

    NASA Technical Reports Server (NTRS)

    Cominsky, A.

    1981-01-01

    Impact-survivable postcrash fire accidents were surveyed. The data base developed includes foreign and domestic accidents involving airlines and jet aircraft. The emphasis was placed on domestic accidents, airlines, and jet aircraft due principally to availability of information. Only transport category aircraft in commercial service designed under FAR Part 25 were considered. A matrix was prepared to show the relationships between the accident characteristics and the fire fatalities. Typical postcrash fire scenaries were identified. Safety concepts were developed for three engineering categories: cabin interiors - cabin subsystems; power plant - engines and fuel systems; and structural mechanics - primary and secondary structures. The parameters identified for concept evaluation are cost, effectiveness, and societal concerns. Three concepts were selected for design definition and cost and effectiveness analysis: improved fire-resistant seat materials; anti-misting kerosene; and additional cabin emergency exits.

  15. Ram-jet Performance

    NASA Technical Reports Server (NTRS)

    Cervenko, A. J.; Friedman, R.

    1956-01-01

    The ram jet is basically one of the most dimple types of aircraft engine. It consists only of an inlet diffuser, a combustion system, and an exit nozzle. A typical ram-jet configuration is shown in figure 128. The engine operates on the Brayton cycle, and ideal cycle efficiency depends only on the ratio of engine to ambient pressure. The increased, engine pressures are obtained by ram action alone, and for this reason the ram jet has zero thrust at zero speed. Therefore, ram-jet-powered aircraft must be boosted to flight speeds close to a Mach number of 1.0 before appreciable thrust is generated by the engine. Since pressure increases are obtained by ram action alone, combustor-inlet pressures and temperatures are controlled by the flight speed, the ambient atmospheric condition, and by the efficiency of the inlet diffuser. These pressures and temperatures, as functions of flight speed and altitude, are shown in figure 129 for the NACA standard atmosphere and for practical values of diffuser efficiency. It can be seen that very wide ranges of combustor-inlet temperatures and pressures may be encountered over the ranges of flight velocity and altitude at which ram jets may be operated. Combustor-inlet temperatures from 500 degrees to 1500 degrees R and inlet pressures from 5 to 100 pounds per square inch absolute represent the approximate ranges of interest in current combustor development work. Since the ram jet has no moving parts in the combustor outlet, higher exhaust-gas temperatures than those used in current turbojets are permissible. Therefore, fuel-air ratios equivalent to maximum rates of air specific impulse or heat release can be used, and, for hydrocarbon fuels, this weight ratio is about 0.070. Lower fuel-air ratios down to about 0.015 may also be required to permit efficient cruise operation. This fuel-air-ratio range of 0.015 to 0.070 used in ram jets can be compared with the fuel-air ratios up to 0.025 encountered in current turbojets. Ram-jet

  16. Refinery Integration of By-Products from Coal-Derived Jet Fuels

    SciTech Connect

    Caroline E. Burgess Clifford; Andre Boehman; Chunshan Song; Bruce Miller; Gareth Mitchell

    2007-03-17

    This report summarizes the accomplishments toward project goals during the no cost extension period of the third year of the project to assess the properties and performance of coal based products. These products are in the gasoline, diesel and fuel oil range and result from coal based jet fuel production from an Air Force funded program. Specific areas of progress include generation of coal based material that has been fractionated into the desired refinery cuts for a third round of testing, the use of a research gasoline engine to test coal-based gasoline, and modification of diesel engines for use in evaluating diesel produced in the project. At the pilot scale, the hydrotreating process was modified to separate the heavy components from the LCO and RCO fractions before hydrotreating in order to improve the performance of the catalysts in further processing. Hydrotreating and hydrogenation of the product has been completed, and due to removal of material before processing, yield of the jet fuel fraction has decreased relative to an increase in the gasoline fraction. Characterization of the gasoline fuel indicates a dominance of single ring alkylcycloalkanes that have a low octane rating; however, blends containing these compounds do not have a negative effect upon gasoline when blended in refinery gasoline streams. Characterization of the diesel fuel indicates a dominance of 3-ring aromatics that have a low cetane value; however, these compounds do not have a negative effect upon diesel when blended in refinery diesel streams. Both gasoline and diesel continue to be tested for combustion performance. The desulfurization of sulfur containing components of coal and petroleum is being studied so that effective conversion of blended coal and petroleum streams can be efficiently converted to useful refinery products. Activated carbons have proven useful to remove the heavy sulfur components, and unsupported Ni/Mo and Ni/Co catalysts have been very effective for

  17. Analytical study of STOL Aircraft in ground effect. Part 1: Nonplanar, nonlinear wing/jet lifting surface method

    NASA Technical Reports Server (NTRS)

    Shollenberger, C. A.; Smyth, D. N.

    1978-01-01

    A nonlinear, nonplanar three dimensional jet flap analysis, applicable to the ground effect problem, is presented. Lifting surface methodology is developed for a wing with arbitrary planform operating in an inviscid and incompressible fluid. The classical, infintely thin jet flap model is employed to simulate power induced effects. An iterative solution procedure is applied within the analysis to successively approximate the jet shape until a converged solution is obtained which closely satisfies jet and wing boundary conditions. Solution characteristics of the method are discussed and example results are presented for unpowered, basic powered and complex powered configurations. Comparisons between predictions of the present method and experimental measurements indicate that the improvement of the jet with the ground plane is important in the analyses of powered lift systems operating in ground proximity. Further development of the method is suggested in the areas of improved solution convergence, more realistic modeling of jet impingement and calculation efficiency enhancements.

  18. Power generation performance of direct flame fuel cell (DFFC) impinged by small jet flames

    NASA Astrophysics Data System (ADS)

    Nakamura, Yuji; Endo, Shota

    2015-10-01

    This paper investigated the effect of cell temperature and product species concentration induced by a small jet flame on the power generation performance of a direct flame fuel cell (DFFC). The cell is placed above the small-scale jet flame and the heated product’s gases are impinged toward it. This system is considered to be the simplest and smallest unit of such power generation devices to have been developed. Methane is used as fuel and an equivalence ratio (φ ) of the mixture (with oxygen) and the distance between the cell and the burner surface (d) are considered as the experimental parameters. It turns out that open circuit voltage increases linearly with the increase of temperature in a wide range of equivalence ratios. However, it increases drastically to the point at which the equivalence ratio becomes small enough (φ   ⩽  2.0 in the present study) within the specific distance range to bring about the appearance of an inner flame. This could provide sufficient heat and oxygen for the anode, contributing to the generation of the cell’s high electric potential. It is also noted that the appearance of the inner flame does not promise to better the performance unless the preferred conditions (high temperature, low oxygen, rich fuel) near the cell are achieved. The Nernst equation works well for predicting the open circuit voltage under the conditions studied. Systematic design of the entire power generation system is preferable when a miniaturized power generation system is considered by applying DFFC.

  19. Advanced thermally stable jet fuels. Technical progress report, August 1992--October 1992

    SciTech Connect

    Schobert, H.H.; Eser, S.; Song, C.; Hatcher, P.G.; Walsh, P.M.; Coleman, M.M.; Bortiatynski, J.; Burgess, C.; Dutta, R.; Gergova, K.; Lai, W.C.; Li, J.; McKinney, D.; Parfitt, D.; Peng, Y.; Sanghani, P.; Yoon, E.

    1993-02-01

    The Penn State program in advanced thermally stable coal-based jet fuels has five borad objectives: (1) development of mechanisms of degradation and solids formation; (2) quantitative measurement of growth of sub-micrometer and miocrometer-sized particles suspended in fuels during thermal stressing; (3) characterization of carbonaceous deposits by various instrumental and microscopic methods; (4) elucidation of the role of additives in retarding the formation of carbonaceous solids; and (5) assessment of the potential of production of high yields of cycloalkanes by direct liquefaction of coal. Pyrolysis of four isomers of butylbenzene was investigated in static microautoclave reactors at 450{degrees}C under 0.69 MPa of UHP N{sub 2}. Thee rates of disappearance of substrates were found to depend upon the bonding energy of C{alpha}-C{beta} bond in the side chain in the initial period of pyrolysis reactions. Possible catalytic effects of metal surfaces on thermal degradation and deposit formation at temperatures >400{degrees}C have been studied. Carbon deposition depends on the composition of the metal surfaces, and also depends on the chemical compositions of the reactants. Thermal stressing of JP-8 was conducted in the presence of alumina, carbonaceous deposits recovered from earlier stressing experiments, activated carbon, carbon black, and graphite. The addition of different solid carbons during thermal stressing leads to different reaction mechanisms. {sup 13}C NMR spectroscopy, along with {sup 13}C-labeling techniques, have been used to examine the thermal stability of a jet fuel sample mixed with 5% benzyl alcohol. Several heterometallic complexes consisting of two transition metals and sulfur in a single molecule were synthesized and tested as precursors of bimetallic dispersed catalysts for liquefaction of a Montana subbituminous and Pittsburgh No. 8 bituminous coals.

  20. Combustion Temperature Measurement by Spontaneous Raman Scattering in a Jet-A Fueled Gas Turbine Combustor Sector

    NASA Technical Reports Server (NTRS)

    Hicks, Yolanda R.; DeGroot, Wilhelmus A.; Locke, Randy J.; Anderson, Robert C.

    2002-01-01

    Spontaneous vibrational Raman scattering was used to measure temperature in an aviation combustor sector burning jet fuel. The inlet temperature ranged from 670 K (750 F) to 756 K (900 F) and pressures from 13 to 55 bar. With the exception of a discrepancy that we attribute to soot, good agreement was seen between the Raman-derived temperatures and the theoretical temperatures calculated from the inlet conditions. The technique used to obtain the temperature uses the relationship between the N2 anti-Stokes and Stokes signals, within a given Raman spectrum. The test was performed using a NASA-concept fuel injector and Jet-A fuel over a range of fuel/air ratios. This work represents the first such measurements in a high-pressure, research aero-combustor facility.