WorldWideScience

Sample records for jet aircraft altitudes

  1. An empirical approach to the measurement of the cosmic radiation field at jet aircraft altitudes

    CERN Document Server

    Green, A R; Lewis, B J; Kitching, F; McCall, M J; Desormeaux, M; Butler, A A

    2005-01-01

    Researchers at the Royal Military College of Canada have accumulated extensive dose measurements performed at jet altitudes on over 160 flights and with a wide variety of detectors including a tissue equivalent proportional counter (TEPC), a smart wide energy neutron detection instrument (SWENDI), bubble detectors, thermoluminescent detectors (TLD) and an ion chamber. The summation of the individual low and high LET results from the latter equipment compared successfully to those from the TEPC on each flight. The data from these numerous worldwide flights have been encapsulated into a program that calculates the radiation dose for any flight in the world at any period in the solar cycle. This experimentally based program, Predictive Code for AIRcrew Exposure (PCAIRE) has been designed to be used by the airline industry to meet national dosimetry requirements. In Canada, for example, such a code can be used, supported by periodic measurements. With this latter requirement in mind and a desire to decrease equip...

  2. NO{sub x} emission indices of subsonic wide-bodied jet aircraft at cruise altitude: In situ measurements and predictions

    Energy Technology Data Exchange (ETDEWEB)

    Schulte, P.; Schlager, H.; Schumann, U. [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Wessling (Germany). Inst. fuer Physik der Atmosphaere; Baughcum, S.L. [Boeing Co., Seattle, WA (United States); Deidewig, F. [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Koeln (Germany). Inst. fuer Antriebstechnik

    1996-10-01

    In situ measurements of NO, NO{sub 2}, and CO{sub 2} volume mixing ratios have been carried out in the near field exhaust plumes of seven subsonic wide-bodied jet aircraft using the DLR research aircraft `Falcon`. For three additional aircraft only NO and CO{sub 2} was measured. Plume ages of 50 s to 150 s have been covered, with maximum observed exhaust gas enhancements of 319 ppbv and 51 ppmv for {Delta}[NO{sub x}] and {Delta}[CO{sub 2}], respectively, relative to ambient values. These measurements are used to derive NO{sub x} emission indices for seven of the individual aircraft/engine combinations. The NO{sub x} emission indices derived range from 12.3 g/kg to 30.4 g/kg. They are compared with predicted emission index values, calculated for the same aircraft engine and the actual conditions using two newly developed fuel flow correlation methods. The calculated emission indices were mostly within or close to the error limits of the measured values. On average, the predictions from both methods were 12% lower than the measured values, with an observed maximum deviation of 25%. The ratio {gamma}=[NO{sub 2}]/[NO{sub x}] found during the present measurements ranged from 0.06 to 0.11 for five daytime cases and was around 0.22 for two nighttime cases. By use of a simple box model of the plume chemistry and dilution these data were used to estimate the initial value {gamma}{sub 0} present at the engine exit plane. {gamma}{sub 0} values between 0 and 0.15 were found. These where applied to estimate the corresponding NO{sub 2} for the three cases where only NO was measured. (orig.)

  3. System for indicating fuel-efficient aircraft altitude

    Science.gov (United States)

    Gary, B. L. (Inventor)

    1984-01-01

    A method and apparatus are provided for indicating the altitude at which an aircraft should fly so the W/d ratio (weight of the aircraft divided by the density of air) more closely approaches the optimum W/d for the aircraft. A passive microwave radiometer on the aircraft is directed at different angles with respect to the horizon to determine the air temperature, and therefore the density of the air, at different altitudes. The weight of the aircraft is known. The altitude of the aircraft is changed to fly the aircraft at an altitude at which is W/d ratio more closely approaches the optimum W/d ratio for that aircraft.

  4. Gaseous ion-composition measurements in the young exhaust plume of jet aircraft at cruising altitudes. Implications for aerosols and gaseous sulfuric acid

    Energy Technology Data Exchange (ETDEWEB)

    Arnold, F.; Wohlfrom, K.H.; Klemm, M.; Schneider, J.; Gollinger, K. [Max-Planck-Inst. for Nuclear Physics, Heidelberg (Germany); Schumann, U.; Busen, R. [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Wessling (Germany). Inst. fuer Physik der Atmosphaere

    1997-12-31

    Mass spectrometric measurements were made in the young exhaust plume of an Airbus (A310) at cruising altitudes at distances between 400 and 800 m behind the Airbus (averaged plume age: 3.4 sec). The measurements indicate that gaseous sulfuric acid (GSA) number densities were less than 1.3 x 10{sup 8} cm{sup -3} which is smaller than the expected total sulfuric acid. Hence the missing sulfuric acid must have been in the aerosol phase. These measurements also indicate a total aerosol surface area density A{sub T} {<=} 5.4 x 10{sup -5} cm{sup 2} per cm{sup 3} which is consistent with simultaneously measured soot and water contrail particles. However, homogeneous nucleation leading to (H{sub 2}SO{sub 4}){sub x}(H{sub 2}O){sub y}-clusters can not be ruled out. (author) 16 refs.

  5. Gaseous ion-composition measurements in the young exhaust plume of jet aircraft at cruising altitudes. Implications for aerosols and gaseous sulfuric acid

    Energy Technology Data Exchange (ETDEWEB)

    Arnold, F; Wohlfrom, K H; Klemm, M; Schneider, J; Gollinger, K [Max-Planck-Inst. for Nuclear Physics, Heidelberg (Germany); Schumann, U; Busen, R [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Wessling (Germany). Inst. fuer Physik der Atmosphaere

    1998-12-31

    Mass spectrometric measurements were made in the young exhaust plume of an Airbus (A310) at cruising altitudes at distances between 400 and 800 m behind the Airbus (averaged plume age: 3.4 sec). The measurements indicate that gaseous sulfuric acid (GSA) number densities were less than 1.3 x 10{sup 8} cm{sup -3} which is smaller than the expected total sulfuric acid. Hence the missing sulfuric acid must have been in the aerosol phase. These measurements also indicate a total aerosol surface area density A{sub T} {<=} 5.4 x 10{sup -5} cm{sup 2} per cm{sup 3} which is consistent with simultaneously measured soot and water contrail particles. However, homogeneous nucleation leading to (H{sub 2}SO{sub 4}){sub x}(H{sub 2}O){sub y}-clusters can not be ruled out. (author) 16 refs.

  6. Monte Carlo Calculation of the Radiation Field at Aircraft Altitudes

    Energy Technology Data Exchange (ETDEWEB)

    Roesler, Stefan

    2001-08-24

    Energy spectra of secondary cosmic rays are calculated for aircraft altitudes and a discrete set of solar modulation parameters and rigidity cutoff values covering all possible conditions. The calculations are based on the Monte Carlo code FLUKA and on the most recent information on the interstellar cosmic ray flux including a detailed model of solar modulation. Results are compared to a large variety of experimental data obtained on ground and aboard of aircrafts and balloons, such as neutron, proton, and muon spectra and yields of charged particles. Furthermore, particle fluence is converted into ambient dose equivalent and effective dose and the dependence of these quantities on height above sea level, solar modulation, and geographic location is studied. Finally, calculated dose equivalent is compared to results of comprehensive measurements performed aboard of aircrafts.

  7. Development and testing of airfoils for high-altitude aircraft

    Science.gov (United States)

    Drela, Mark (Principal Investigator)

    1996-01-01

    Specific tasks included airfoil design; study of airfoil constraints on pullout maneuver; selection of tail airfoils; examination of wing twist; test section instrumentation and layout; and integrated airfoil/heat-exchanger tests. In the course of designing the airfoil, specifically for the APEX test vehicle, extensive studies were made over the Mach and Reynolds number ranges of interest. It is intended to be representative of airfoils required for lightweight aircraft operating at extreme altitudes, which is the primary research objective of the APEX program. Also considered were thickness, pitching moment, and off-design behavior. The maximum ceiling parameter M(exp 2)C(sub L) value achievable by the Apex-16 airfoil was found to be a strong constraint on the pullout maneuver. The NACA 1410 and 2410 airfoils (inverted) were identified as good candidates for the tail, with predictable behavior at low Reynolds numbers and good tolerance to flap deflections. With regards to wing twist, it was decided that a simple flat wing was a reasonable compromise. The test section instrumentation consisted of surface pressure taps, wake rakes, surface-mounted microphones, and skin-friction gauges. Also, a modest wind tunnel test was performed for an integrated airfoil/heat-exchanger configuration, which is currently on Aurora's 'Theseus' aircraft. Although not directly related to the APEX tests, the aerodynamics or heat exchangers has been identified as a crucial aspect of designing high-altitude aircraft and hence is relevant to the ERAST program.

  8. Capabilities of unmanned aircraft vehicles for low altitude weed detection

    Science.gov (United States)

    Pflanz, Michael; Nordmeyer, Henning

    2014-05-01

    Sustainable crop production and food security require a consumer and environmental safe plant protection. It is recently known, that precise weed monitoring approaches could help apply pesticides corresponding to field variability. In this regard the site-specific weed management may contribute to an application of herbicides with higher ecologically aware and economical savings. First attempts of precision agriculture date back to the 1980's. Since that time, remote sensing from satellites or manned aircrafts have been investigated and used in agricultural practice, but are currently inadequate for the separation of weeds in an early growth stage from cultivated plants. In contrast, low-cost image capturing at low altitude from unmanned aircraft vehicles (UAV) provides higher spatial resolution and almost real-time processing. Particularly, rotary-wing aircrafts are suitable for precise path or stationary flight. This minimises motion blur and provides better image overlapping for stitching and mapping procedures. Through improved image analyses and the recent increase in the availability of microcontrollers and powerful batteries for UAVs, it can be expected that the spatial mapping of weeds will be enhanced in the future. A six rotors microcopter was equipped with a modified RGB camera taking images from agricultural fields. The hexacopter operates within predefined pathways at adjusted altitudes (from 5 to 10 m) by using GPS navigation. Different scenarios of optical weed detection have been carried out regarding to variable altitude, image resolution, weed and crop growth stages. Our experiences showed high capabilities for site-specific weed control. Image analyses with regard to recognition of weed patches can be used to adapt herbicide application to varying weed occurrence across a field.

  9. Energy management strategy for solar-powered high-altitude long-endurance aircraft

    International Nuclear Information System (INIS)

    Gao, Xian-Zhong; Hou, Zhong-Xi; Guo, Zheng; Liu, Jian-Xia; Chen, Xiao-Qian

    2013-01-01

    Highlights: ► A new Energy Management Strategy (EMS) for high-altitude solar-powered aircraft is purposed. ► The simulations show that the aircraft can always keep the altitude above 16 km with the proposed EMS. ► The proposed EMS is capable to alleviate the power consumed for aircraft during night. ► The main technologies to improve the flight performance of aircraft are analyzed. - Abstract: Development of solar-powered High-Altitude Long-Endurance (HALE) aircraft has a great impact on both military and civil aviation industries since its features in high-altitude and energy source can be considered inexhaustible. Owing to the development constraints of rechargeable batteries, the solar-powered HALE aircraft must take amount of rechargeable batteries to fulfill the energy requirement in night, which greatly limits the operation altitude of aircraft. In order to solve this problem, a new Energy Management Strategy (EMS) is proposed based on the idea that the solar energy can be partly stored in gravitational potential in daytime. The flight path of HALE aircraft is divided into three stages. During the stage 1, the solar energy is stored in both lithium–sulfur battery and gravitational potential. The gravitational potential is released in stage 2 by gravitational gliding and the required power in stage 3 is supplied by lithium–sulfur battery. Correspondingly, the EMS is designed for each stage. The simulation results show that the aircraft can always keep the altitude above 16 km with the proposed EMS, and the power consumed during night can be also alleviated. Comparing with the current EMS, about 23.5% energy is remained in batteries with the proposed EMS during one day–night cycle. The sensitivities of the improvement of crucial technologies to the performance of aircraft are also analyzed. The results show that the enhancement of control and structural system, lithium–sulfur battery, and solar cell are ranked in descending order for the

  10. Aircraft Survivability: Survivability in The Low Altitude Regime, Summer 2009

    Science.gov (United States)

    2009-01-01

    elevation, sun location, temperature, humidity, ozone level, visibility, cloud coverage, and wind speed and direction. Survivability in the Low Altitude...JASP Summer PMSG 14–16 July 2009 Key West, FL AUG 45th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit 2–5 August 2009 Denver, CO

  11. Perseus A High Altitude Remotely Piloted Aircraft being Towed in Flight

    Science.gov (United States)

    1994-01-01

    Perseus A, a remotely piloted, high-altitude research vehicle designed by Aurora Flight Sciences Corp., takes off from Rogers Dry Lake at the Dryden Flight Research Center, Edwards, California. The Perseus was towed into the air by a ground vehicle. At about 700 ft. the aircraft was released and the engine turned the propeller to take the plane to its desired altitude. Perseus B is a remotely piloted aircraft developed as a design-performance testbed under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) project. Perseus is one of several flight vehicles involved in the ERAST project. A piston engine, propeller-powered aircraft, Perseus was designed and built by Aurora Flight Sciences Corporation, Manassas, Virginia. The objectives of Perseus B's ERAST flight tests have been to reach and maintain horizontal flight above altitudes of 60,000 feet and demonstrate the capability to fly missions lasting from 8 to 24 hours, depending on payload and altitude requirements. The Perseus B aircraft established an unofficial altitude record for a single-engine, propeller-driven, remotely piloted aircraft on June 27, 1998. It reached an altitude of 60,280 feet. In 1999, several modifications were made to the Perseus aircraft including engine, avionics, and flight-control-system improvements. These improvements were evaluated in a series of operational readiness and test missions at the Dryden Flight Research Center, Edwards, California. Perseus is a high-wing monoplane with a conventional tail design. Its narrow, straight, high-aspect-ratio wing is mounted atop the fuselage. The aircraft is pusher-designed with the propeller mounted in the rear. This design allows for interchangeable scientific-instrument payloads to be placed in the forward fuselage. The design also allows for unobstructed airflow to the sensors and other devices mounted in the payload compartment. The Perseus B that underwent test and development in 1999 was the third generation of the

  12. Analysis of the Hybrid Power System for High-Altitude Unmanned Aircraft

    Directory of Open Access Journals (Sweden)

    Kangwen Sun

    2015-01-01

    Full Text Available The application of single solar array on high-altitude unmanned aircraft will waste energy because of its low conversion efficiency. Furthermore, since its energy utilization is limited, the surface temperature of solar array will rise to 70°C due to the waste solar energy, thus reducing the electrical performance of the solar array. In order to reuse the energy converted into heat by solar array, a hybrid power system is presented in this paper. In the hybrid power system, a new electricity-generating method is adopted to spread the photovoltaic cell on the wing surface and arrange photothermal power in the wing box section. Because the temperature on the back of photovoltaic cell is high, it can be used as the high-temperature heat source. The lower wing surface can be a low-temperature cold source. A high-altitude unmanned aircraft was used to analyze the performances of pure solar-powered aircraft and hybrid powered aircraft. The analysis result showed that the hybrid system could reduce the area of wing by 19% and that high-altitude unmanned aircraft with a 35 m or less wingspan could raise the utilization rate of solar energy per unit area after adopting the hybrid power system.

  13. Reduction of Altitude Diffuser Jet Noise Using Water Injection

    Science.gov (United States)

    Allgood, Daniel C.; Saunders, Grady P.; Langford, Lester A.

    2011-01-01

    A feasibility study on the effects of injecting water into the exhaust plume of an altitude rocket diffuser for the purpose of reducing the far-field acoustic noise has been performed. Water injection design parameters such as axial placement, angle of injection, diameter of injectors, and mass flow rate of water have been systematically varied during the operation of a subscale altitude test facility. The changes in acoustic far-field noise were measured with an array of free-field microphones in order to quantify the effects of the water injection on overall sound pressure level spectra and directivity. The results showed significant reductions in noise levels were possible with optimum conditions corresponding to water injection at or just upstream of the exit plane of the diffuser. Increasing the angle and mass flow rate of water injection also showed improvements in noise reduction. However, a limit on the maximum water flow rate existed as too large of flow rate could result in un-starting the supersonic diffuser.

  14. Radiation Safety Issues in High Altitude Commercial Aircraft

    Science.gov (United States)

    Wilson, John W.; Cucinotta, Francis A.; Shinn, Judy L.

    1995-01-01

    The development of a global economy makes the outlook for high speed commercial intercontinental flight feasible, and the development of various configurations operating from 20 to 30 km have been proposed. In addition to the still unresolved issues relating to current commercial operations (12-16 km), the higher dose rates associated with the higher operating altitudes makes il imperative that the uncertainties in the atmospheric radiation environment and the associated health risks be re-examined. Atmospheric radiation associated with the galactic cosmic rays forms a background level which may, under some circumstances, exceed newly recommended allowable exposure limits proposed on the basis of recent evaluations of the A -bomb survivor data (due to increased risk coefficients). These larger risk coefficients, within the context of the methodology for estimating exposure limits, are resulting in exceedingly low estimated allowable exposure limits which may impact even present day flight operations and was the reason for the CEC workshop in Luxembourg (1990). At higher operating altitudes, solar particles events can produce exposures many orders of magnitude above background levels and pose significant health risks to the most sensitive individuals (such as during pregnancy). In this case the appropriate quality factors are undefined, and some evidence exists which indicates that the quality factor for stochastic effects is a substantial underestimate.

  15. Effect of power system technology and mission requirements on high altitude long endurance aircraft

    Science.gov (United States)

    Colozza, Anthony J.

    1994-01-01

    An analysis was performed to determine how various power system components and mission requirements affect the sizing of a solar powered long endurance aircraft. The aircraft power system consists of photovoltaic cells and a regenerative fuel cell. Various characteristics of these components, such as PV cell type, PV cell mass, PV cell efficiency, fuel cell efficiency, and fuel cell specific mass, were varied to determine what effect they had on the aircraft sizing for a given mission. Mission parameters, such as time of year, flight altitude, flight latitude, and payload mass and power, were also altered to determine how mission constraints affect the aircraft sizing. An aircraft analysis method which determines the aircraft configuration, aspect ratio, wing area, and total mass, for maximum endurance or minimum required power based on the stated power system and mission parameters is presented. The results indicate that, for the power system, the greatest benefit can be gained by increasing the fuel cell specific energy. Mission requirements also substantially affect the aircraft size. By limiting the time of year the aircraft is required to fly at high northern or southern latitudes, a significant reduction in aircraft size or increase in payload capacity can be achieved.

  16. A Strong High Altitude Narrow Jet At Saturn'S Equator From Cassini/ISS Images

    Science.gov (United States)

    Garcia-Melendo, Enrique; Sánchez-Lavega, A.; Legarreta, J.; Pérez-Hoyos, S.; Hueso, R.

    2010-10-01

    The intense equatorial eastward jets observed at cloud level in Jupiter and Saturn, represent a major challenge for geophysical fluid dynamics. Saturn's equatorial jet is of particular interest in view of its three dimensional structure, suspected large temporal variability, and related stratospheric semiannual oscillation. Here we report the discovery at the upper cloud level of an extremely narrow and strong jet centered in the middle of the broad equatorial jet. Previously published works on Saturn's equatorial winds at cloud level provided only a partial coverage. Automatic correlation of brightness scans and manually tracked cloud features, retrieved from images obtained by the Cassini Imaging Science Subsystem (ISS), show that the jet reaches 430 ms-1 with a peak speed difference of 180 ms-1 relative to nearby latitudes at 60 mbar and 390 ms-1 at depths > 500 mbar. Images were obtained in two filters: MT3, centred at the 889nm strong methane absorption band, and CB3 centred at the near infrared 939nm continuum, which are sensitive to different altitude levels at the upper clouds and hazes. Contrarily to what is observed in other latitudes, its velocity increases with altitude. Our findings helps to extend the view we have of the equatorial stratospheric dynamics of fast rotating planets beyond the best known terrestrial environment, and extract more general consequences of the interaction between waves and mean flow. It remains to be known if this equatorial jet structure, now determined in detail in three dimensions, is permanent or variable with the seasonal solar insolation cycle, including the variable shadow cast by the rings. EGM, ASL, JL, SPH, and RH have been funded by the Spanish MICIIN AYA2009-10701 with FEDER support and ASL, JL, SPH, and RH by Grupos Gobierno Vasco IT-464-07

  17. Integrated Modelling of an Unmanned High-Altitude Solar-Powered Aircraft for Control Law Design Analysis

    OpenAIRE

    Klöckner, Andreas; Leitner, Martin; Schlabe, Daniel; Looye, Gertjan

    2013-01-01

    Solar-powered high-altitude unmanned platforms are highly optimized and integrated aircraft. In order to account for the complex, multi-physical interactions between their systems, we propose using integrated simulation models throughout the aircraft’s life cycle. Especially small teams with limited ressources should benefit from this approach. In this paper, we describe our approach to an integrated model of the Electric High-Altitude Solar-Powered Aircraft ELHASPA. It includes aspects of th...

  18. Methods for reducing pollutant emissions from jet aircraft

    Science.gov (United States)

    Butze, H. F.

    1971-01-01

    Pollutant emissions from jet aircraft and combustion research aimed at reducing these emissions are defined. The problem of smoke formation and results achieved in smoke reduction from commercial combustors are discussed. Expermental results of parametric tests performed on both conventional and experimental combustors over a range of combustor-inlet conditions are presented. Combustor design techniques for reducing pollutant emissions are discussed. Improved fuel atomization resulting from the use of air-assist fuel nozzles has brought about significant reductions in hydrocarbon and carbon monoxide emissions at idle. Diffuser tests have shown that the combustor-inlet airflow profile can be controlled through the use of diffuser-wall bleed and that it may thus be possible to reduce emissions by controlling combustor airflow distribution. Emissions of nitric oxide from a shortlength annular swirl-can combustor were significantly lower than those from a conventional combustor operating at similar conditions.

  19. Engine jet entrainment in the near field of an aircraft

    Energy Technology Data Exchange (ETDEWEB)

    Garnier, F.; Jacquin, L.; Laverdant, A. [Office National d`Etudes et de Recherches Aerospatiales (ONERA), 92 - Chatillon (France)

    1997-12-31

    A simplified approach has been applied to analyse the mixing and entrainment processes of the engine exhaust through their interaction with the vortex wake of an aircraft. These investigations are focused on the near filed, extending from exit nozzle to the beginning of the vortex phase (i.e. to about twenty seconds after the wake is generated). This study is performed using an integral model and a numerical simulation for a two-engine large civil aircraft. The properties of the wing-tip vortices on the calculation of the dilution ratio (defined as a tracer concentration) have been shown. The mixing process is also affected by the buoyancy effect, but only after the jet regime, when the trapping in the vortex core has occurred. Qualitative comparison with contrail photography shows similar features. Finally the distortion and stretching of the plume streamlines inside the vortices can be observed, and the role of the descent of the vortices on the maximum tracer concentration has been discussed. (author) 19 refs.

  20. Engine jet entrainment in the near field of an aircraft

    Energy Technology Data Exchange (ETDEWEB)

    Garnier, F; Jacquin, L; Laverdant, A [Office National d` Etudes et de Recherches Aerospatiales (ONERA), 92 - Chatillon (France)

    1998-12-31

    A simplified approach has been applied to analyse the mixing and entrainment processes of the engine exhaust through their interaction with the vortex wake of an aircraft. These investigations are focused on the near filed, extending from exit nozzle to the beginning of the vortex phase (i.e. to about twenty seconds after the wake is generated). This study is performed using an integral model and a numerical simulation for a two-engine large civil aircraft. The properties of the wing-tip vortices on the calculation of the dilution ratio (defined as a tracer concentration) have been shown. The mixing process is also affected by the buoyancy effect, but only after the jet regime, when the trapping in the vortex core has occurred. Qualitative comparison with contrail photography shows similar features. Finally the distortion and stretching of the plume streamlines inside the vortices can be observed, and the role of the descent of the vortices on the maximum tracer concentration has been discussed. (author) 19 refs.

  1. Measuring the aerial application of oil dispersant from very large aircraft at moderate altitude

    International Nuclear Information System (INIS)

    Fay, R.R.; Giammona, C.P.; Binkley, K.; Engelhardt, F.R.

    1993-01-01

    As part of a study of various aspects of oil dispersant application technology, a comparison study was conducted employing the Airborne Dispersant Delivery System (ADDS) pack and the Modular Aerial Spray System (MASS) in C-130 Hercules aircraft at altitudes of 50-150 ft above ground and at speeds up to 200 knots. Dyed Corexit 9527 was applied at a target dose rate of 5 gal/acre over a collection grid composed of metal trays, Kromekote cards, oil-sensitive cards, a continuous trough, and a WRK string collector. Analysis of the collected dispersant was done by colorimetry, fluorometry, and image analysis. Correlations through the different methodologies demonstrated that high speed, moderate altitude application of oil dispersant could be successful in delivering dispersant to the surface at effective concentration and drop size. Environmental studies of the test area showed no residual dispersant in the soil following cessation of spraying. 1 ref

  2. In situ emission measurements in the wake of subsonic jet airliners at cruise altitude

    Energy Technology Data Exchange (ETDEWEB)

    Schulte, P; Schlager, H; Schumann, U [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Wessling (Germany). Inst. fuer Physik der Atmosphaere; Baughcum, St [Boeing Co., Seattle, WA (United States); Deidewig, F [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Koeln (Germany). Inst. fuer Antriebstechnik

    1998-12-31

    In the course of the POLINAT campaigns of 1994 and 1995 several flights were carried out to measure NO{sub x} and CO{sub 2} in the young exhaust plumes of commercial wide-bodied jet airlines at altitude. From these measurements in flight NO{sub x} emission indices were derived which were used to test current NO{sub x} emission index prediction methods. Taking into account the error of the measurements and uncertainties in the input parameters for the predictions, the results of the two fuel flow base prediction methods agreed well with the measured values. (author) 13 refs.

  3. In situ emission measurements in the wake of subsonic jet airliners at cruise altitude

    Energy Technology Data Exchange (ETDEWEB)

    Schulte, P.; Schlager, H.; Schumann, U. [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Wessling (Germany). Inst. fuer Physik der Atmosphaere; Baughcum, St. [Boeing Co., Seattle, WA (United States); Deidewig, F. [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Koeln (Germany). Inst. fuer Antriebstechnik

    1997-12-31

    In the course of the POLINAT campaigns of 1994 and 1995 several flights were carried out to measure NO{sub x} and CO{sub 2} in the young exhaust plumes of commercial wide-bodied jet airlines at altitude. From these measurements in flight NO{sub x} emission indices were derived which were used to test current NO{sub x} emission index prediction methods. Taking into account the error of the measurements and uncertainties in the input parameters for the predictions, the results of the two fuel flow base prediction methods agreed well with the measured values. (author) 13 refs.

  4. 76 FR 35912 - Business Jet Aircraft Industry: Structure and Factors Affecting Competitiveness; Institution of...

    Science.gov (United States)

    2011-06-20

    ... structure of the global industry, including supply chain relationships and foreign direct investment; 2. An... competitiveness of the business jet aircraft industry in the United States, Brazil, Canada, Europe, and China. To...

  5. Engineering assessment of in situ sulfate production onboard aircraft at high altitude

    Science.gov (United States)

    Smith, J.; Dykema, J. A.; Keith, D.

    2016-12-01

    Stratospheric injection of scattering aerosols has been proposed as a way to reduce global temperature increases by decreasing net atmospheric radiative forcing. Several methods have been suggested as a means of implementing solar geoengineering, and high altitude aircraft have been identified as an accessible means delivering sulfate aerosols to the lower and mid-stratosphere. This research initiative analyzes the design features of an onboard open cycle chemical plant capable of in situ sulfur to sulfate conversion, and compares the required mass to that of transporting pre-fabricated gaseous or liquid sulfate aerosol precursors. Scaling from aero-derivative gas turbine engines, commercial catalytic converters, and existing aerospace materials indicate that aircraft equipped with such a system could provide a substantial mass benefit compared to direct transport of compound sulfate products.

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

    Science.gov (United States)

    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.

  7. Unmanned Aircraft Systems Traffic Management (UTM) Safely Enabling UAS Operations in Low-Altitude Airspace

    Science.gov (United States)

    Kopardekar, Parimal H.

    2016-01-01

    Unmanned Aircraft System (UAS) Traffic Management (UTM) Enabling Civilian Low-Altitude Airspace and Unmanned Aircraft System Operations What is the problem? Many beneficial civilian applications of UAS have been proposed, from goods delivery and infrastructure surveillance, to search and rescue, and agricultural monitoring. Currently, there is no established infrastructure to enable and safely manage the widespread use of low-altitude airspace and UAS operations, regardless of the type of UAS. A UAS traffic management (UTM) system for low-altitude airspace may be needed, perhaps leveraging concepts from the system of roads, lanes, stop signs, rules and lights that govern vehicles on the ground today, whether the vehicles are driven by humans or are automated. What system technologies is NASA exploring? Building on its legacy of work in air traffic management for crewed aircraft, NASA is researching prototype technologies for a UAS Traffic Management (UTM) system that could develop airspace integration requirements for enabling safe, efficient low-altitude operations. While incorporating lessons learned from the today's well-established air traffic management system, which was a response that grew out of a mid-air collision over the Grand Canyon in the early days of commercial aviation, the UTM system would enable safe and efficient low-altitude airspace operations by providing services such as airspace design, corridors, dynamic geofencing, severe weather and wind avoidance, congestion management, terrain avoidance, route planning and re-routing, separation management, sequencing and spacing, and contingency management. One of the attributes of the UTM system is that it would not require human operators to monitor every vehicle continuously. The system could provide to human managers the data to make strategic decisions related to initiation, continuation, and termination of airspace operations. This approach would ensure that only authenticated UAS could operate

  8. Supercharging system behavior for high altitude operation of an aircraft 2-stroke Diesel engine

    International Nuclear Information System (INIS)

    Carlucci, Antonio Paolo; Ficarella, Antonio; Laforgia, Domenico; Renna, Alessandro

    2015-01-01

    Highlights: • Different supercharging architectures have been compared for an aircraft 2T engine. • The supercharging architectures are compared to minimize the fuel consumption. • The architecture with the highest conversion efficiency was determined. - Abstract: Different studies on both 2- and 4-stroke engines have shown how the choice of different supercharging architectures can influence engine performance. Among them, architectures coupling one turbocharger with a mechanical compressor or two turbochargers are found to be the most performing in terms of engine output power and efficiency. However, defining the best supercharging architecture for aircraft 2-stroke engines is a quite complex task because the supercharging system as well as the ambient conditions influence the engine performance/efficiency. This is due to the close interaction between supercharging, trapping, scavenging and combustion processes. The aim of the present work is the comparison between different architectures (single turbocharger, double turbocharger, single turbocharger combined with a mechanical compressor, single turbocharger with an electrically-assisted turbocharger, with intercooler or aftercooler) designed to supercharge an aircraft 2-stroke Diesel engine for general aviation and unmanned aerial vehicles characterized by a very high altitude operation and long fuel distance. A 1D model of the engine purposely designed has been used to compare the performance of the different supercharging systems in terms of power, fuel consumption, and their effect on trapping and scavenging efficiency at different altitudes. The analysis shows that the engine target power is reached by a 2 turbochargers architecture; in this way, in fact, the cylinder filling, and consequently the engine performance, are maximized. Moreover, it is shown that the performance of a 2 turbochargers architecture performance can be further improved connecting electrically and not mechanically the low

  9. Validation of modelling the radiation exposure due to solar particle events at aircraft altitudes

    International Nuclear Information System (INIS)

    Beck, P.; Bartlett, D. T.; Bilski, P.; Dyer, C.; Flueckiger, E.; Fuller, N.; Lantos, P.; Reitz, G.; Ruehm, W.; Spurny, F.; Taylor, G.; Trompier, F.; Wissmann, F.

    2008-01-01

    Dose assessment procedures for cosmic radiation exposure of aircraft crew have been introduced in most European countries in accordance with the corresponding European directive and national regulations. However, the radiation exposure due to solar particle events is still a matter of scientific research. Here we describe the European research project CONRAD, WP6, Subgroup-B, about the current status of available solar storm measurements and existing models for dose estimation at flight altitudes during solar particle events leading to ground level enhancement (GLE). Three models for the numerical dose estimation during GLEs are discussed. Some of the models agree with limited experimental data reasonably well. Analysis of GLEs during geomagnetically disturbed conditions is still complex and time consuming. Currently available solar particle event models can disagree with each other by an order of magnitude. Further research and verification by on-board measurements is still needed. (authors)

  10. Jet stream winds - Comparisons of analyses with independent aircraft data over Southwest Asia

    Science.gov (United States)

    Tenenbaum, J.

    1991-01-01

    Cruise-level wind data from commercial aircraft are obtained, and these data are compared with operational jet stream analyses over southwest Asia, an area of limited conventional data. Results from an ensemble of 11 cases during January 1989 and individual cases during December 1988-March 1989 are presented. The key results are: (1) European Centre for Medium-Range Weather Forecasts (ECMWF), National Meteorological Center, and United Kingdom Meteorological Office analyses of the subtropical jet in southwest Asia are 11 percent, 17 percent, and 17 percent weaker, respectively, than aircraft observations; (2) analyzed poleward shears range up to 1 f (0.00007/s) compared with up to 3 f (0.00021/s) in the aircraft observations where f is the local Coriolis parameters; (3) the ECMWF errors are largest at the base of the jet; (4) the mean ECMWF core location is latitudinally correct but has an rms latitude variance of 1.5 deg; (5) isolated erroneous radiosondes produce unmeteorological structures in the analyzed subtropical jet stream; and (6) the increased utilization of automated aircraft reports is likely to produce a spurious secular increase in the apparent strength of the jets. The magnitude and spatial extent of the errors seen are near limits of current GCM resolution (100 km) but should be resolvable. The results imply that studies of GCM systematic jet stream wind errors in weather and climate forecasts must be interpreted with caution in this region.

  11. Dynamics modeling and control of a transport aircraft for ultra-low altitude airdrop

    Directory of Open Access Journals (Sweden)

    Liu Ri

    2015-04-01

    Full Text Available The nonlinear aircraft model with heavy cargo moving inside is derived by using the separation body method, which can describe the influence of the moving cargo on the aircraft attitude and altitude accurately. Furthermore, the nonlinear system is decoupled and linearized through the input–output feedback linearization method. On this basis, an iterative quasi-sliding mode (SM flight controller for speed and pitch angle control is proposed. At the first-level SM, a global dynamic switching function is introduced thus eliminating the reaching phase of the sliding motion. At the second-level SM, a nonlinear function with the property of “smaller errors correspond to bigger gains and bigger errors correspond to saturated gains” is designed to form an integral sliding manifold, and the overcompensation of the integral term to big errors is weakened. Lyapunov-based analysis shows that the controller with strong robustness can reject both constant and time-varying model uncertainties. The performance of the proposed control strategy is verified in a maximum load airdrop mission.

  12. Real-Time Autonomous Obstacle Avoidance for Low-Altitude Fixed-Wing Aircraft

    Science.gov (United States)

    Owlia, Shahboddin

    The GeoSurv II is an Unmanned Aerial Vehicle (UAV) being developed by Carleton University and Sander Geophysics. This thesis is in support of the GeoSurv II project. The objective of the GeoSurv II project is to create a fully autonomous UAV capable of performing geophysical surveys. In order to achieve this level of autonomy, the UAV, which due to the nature of its surveys flies at low altitude, must be able to avoid potential obstacles such as trees, powerlines, telecommunication towers, etc. Developing a method to avoid these obstacles is the objective of this thesis. The literature is rich in methods for trajectory planning and mid-air collision avoidance with other aircraft. In contrast, in this thesis, a method for avoiding static obstacles that are not known a priori is developed. The potential flow theory and panel method are borrowed from fluid mechanics and are employed to generate evasive maneuvers when obstacles are encountered. By means of appropriate modelling of obstacles, the aircraft's constraints are taken into account such that the evasive maneuvers are feasible for the UAV. Moreover, the method is developed with consideration of the limitations of obstacle detection in GeoSurv II. Due to the unavailability of the GeoSurv II aircraft, and the lack of a complete model for GeoSurv II, the method developed is implemented on the non-linear model of the Aerosonde UAV. The Aerosonde model is then subjected to various obstacle scenarios and it is seen that the UAV successfully avoids the obstacles.

  13. Impact of pulsed jet actuators on aircraft mass and fuel consumption

    NARCIS (Netherlands)

    Bertels, F.G.A.; van Dijk, R.E.C.; Elmendorp, R.J.M.; Vos, R.

    2016-01-01

    Pulsed jet actuators (PJAs) are one of the candidate technologies to be integrated in Fowler flaps to increase the maximum lift coefficient of transport aircraft in the landing configuration. The total system consists of the actuators plus sensors, a piping system to supply pressurized air and a

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

    Science.gov (United States)

    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.

  15. COMPARISON OF COSMIC RAYS RADIATION DETECTORS ON-BOARD COMMERCIAL JET AIRCRAFT

    Czech Academy of Sciences Publication Activity Database

    Kubančák, Ján; Ambrožová, Iva; Pachnerová Brabcová, Kateřina; Jakoubek, J.; Kyselová, D.; Ploc, Ondřej; Bemš, J.; Štěpán, Václav; Uchihori, Y.

    2015-01-01

    Roč. 164, č. 4 (2015), s. 484-488 ISSN 0144-8420 R&D Projects: GA MŠk(CZ) LG13031 Institutional support: RVO:61389005 Keywords : cosmic radiation * commercial jet aircraft * radiation dose Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 0.894, year: 2015

  16. Active aeroelastic control aspects of an aircraft wing by using synthetic jet actuators : Modeling, simulations, experiments

    NARCIS (Netherlands)

    Donnell, K.O.; Schober, S.; Stolk, M.; Marzocca, P.; De Breuker, R.; Abdalla, M.; Nicolini, E.; Gürdal, Z.

    2007-01-01

    This paper discusses modeling, simulations and experimental aspects of active aeroelastic control on aircraft wings by using Synthetic Jet Actuators (SJAs). SJAs, a particular class of zero-net mass-flux actuators, have shown very promising results in numerous aeronautical applications, such as

  17. Longitudinal Static Stability and wake visualization of high altitude long endurance aircraft developed in Bandung institute of technology

    Science.gov (United States)

    Irsyad Lukman, E.; Agoes Moelyadi, M.

    2018-04-01

    A High Altitude Long Endurance (HALE) Unamanned Aerial Vehicle (UAV) is currently being researched in Bandung Institute of Technology. The HALE is designed to be a pseudo-sattelite for information and communication purpose in Indonesia. This paper would present the longitudinal static stability of the aircraft that was analysed using DATCOM as well as simulation of the wing using ANSYS CFX. Result shows that the aircraft has acceptable stability and the wake from the wing at climbing condition cannot be ignored, however it does not affect the horizontal tail.

  18. Spatial Heterodyne Observation of Water (SHOW) from a high altitude aircraft

    Science.gov (United States)

    Bourassa, A. E.; Langille, J.; Solheim, B.; Degenstein, D. A.; Letros, D.; Lloyd, N. D.; Loewen, P.

    2017-12-01

    The Spatial Heterodyne Observations of Water instrument (SHOW) is limb-sounding satellite prototype that is being developed in collaboration between the University of Saskatchewan, York University, the Canadian Space Agency and ABB. The SHOW instrument combines a field-widened SHS with an imaging system to observe limb-scattered sunlight in a vibrational band of water (1363 nm - 1366 nm). Currently, the instrument has been optimized for deployment on NASA's ER-2 aircraft. Flying at an altitude of 70, 000 ft the ER-2 configuration and SHOW viewing geometry provides high spatial resolution (limb-measurements of water vapor in the Upper troposphere and lower stratosphere region. During an observation campaign from July 15 - July 22, the SHOW instrument performed 10 hours of observations from the ER-2. This paper describes the SHOW measurement technique and presents the preliminary analysis and results from these flights. These observations are used to validate the SHOW measurement technique and demonstrate the sampling capabilities of the instrument.

  19. NASA/USRA high altitude research aircraft. Gryphon: Soar like an eagle with the roar of a lion

    Science.gov (United States)

    Rivera, Jose; Nunes, Anne; Mcray, Mike; Wong, Walter; Ong, Audrey; Coble, Scott

    1991-01-01

    At the equator, the ozone layer ranges from 65,000 to 130,000+ feet. This is beyond the capabilities of the ER-2, which is NASA's current high altitude reconnaissance aircraft. The Universities Space Research Association, in cooperation with NASA, is sponsoring an undergraduate program which is geared to designing an aircraft that can study the ozoned layer at the equator. This aircraft must be able to satisfy four mission profiles. Mission one is a polar mission which ranges from Chile to the South Pole and back to Chile, a total range of 6000 n. mi. at 100,000 feet with a 2500 lb. payload. The second mission is also a polar mission with a decreased altitude of 70,000 feet and an increased payload of 4000 lb. For the third mission, the aircraft will take-off at NASA Ames, cruise at 100,000 feet carrying a 2500 lb. payload, and land in Puerto Montt, Chile. The final mission requires the aircraft to take-off at NASA Ames, cruise at 100,000 feet with a 1000 lb. payload, make an excursion to 120,000 feet, and land at Howard AFB, Panama. All three missions require that a subsonic Mach number be maintained due to constraints imposed by the air sampling equipment. The aircraft need not be manned for all four missions. Three aircraft configurations were determined to be the most suitable for meeting the above requirements. The performance of each configuration is analyzed to investigate the feasibility of the project requirements. In the event that a requirement can not be obtained within the given constraints, recommendations for proposal modifications are given.

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

    Science.gov (United States)

    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.

  1. Experimental characterization of the COndensation PArticle counting System for high altitude aircraft-borne application

    Directory of Open Access Journals (Sweden)

    S. Borrmann

    2009-06-01

    Full Text Available A characterization of the ultra-fine aerosol particle counter COPAS (COndensation PArticle counting System for operation on board the Russian high altitude research aircraft M-55 Geophysika is presented. The COPAS instrument consists of an aerosol inlet and two dual-channel continuous flow Condensation Particle Counters (CPCs operated with the chlorofluorocarbon FC-43. It operates at pressures between 400 and 50 hPa for aerosol detection in the particle diameter (dp range from 6 nm up to 1 μm. The aerosol inlet, designed for the M-55, is characterized with respect to aspiration, transmission, and transport losses. The experimental characterization of counting efficiencies of three CPCs yields dp50 (50% detection particle diameter of 6 nm, 11 nm, and 15 nm at temperature differences (ΔT between saturator and condenser of 17°C, 30°C, and 33°C, respectively. Non-volatile particles are quantified with a fourth CPC, with dp50=11 nm. It includes an aerosol heating line (250°C to evaporate H2SO4-H2O particles of 11 nm<dp<200 nm at pressures between 70 and 300 hPa. An instrumental in-flight inter-comparison of the different COPAS CPCs yields correlation coefficients of 0.996 and 0.985. The particle emission index for the M-55 in the range of 1.4–8.4×1016 kg−1 fuel burned has been estimated based on measurements of the Geophysika's own exhaust.

  2. Aging Evaluation Programs for Jet Transport Aircraft Structural Integrity

    Directory of Open Access Journals (Sweden)

    Borivoj Galović

    2012-10-01

    Full Text Available The paper deals with criteria and procedures in evaluationof timely preventive maintenance recommendations that willsupport continued safe operation of aging jet transports untiltheir retirement from service. The active service life of commercialaircraft has increased in recent years as a result of low fuelcost, and increasing costs and delivery times for fleet replacements.Air transport industry consensus is that older jet transportswill continue in service despite anticipated substantial increasesin required maintenance. Design concepts, supportedby testing, have worked well due to the system that is used to ensureflying safety. Continuing structural integrity by inspectionand overhaul recommendation above the level contained inmaintenance and service bulletins is additional requirement, insuch cases. Airplane structural safety depends on the performanceof all participants in the system and the responsibility forsafety cannot be delegated to a single participant. This systemhas three major participants: the manufacturers who design,build and support airplanes in service, the airlines who operate,inspect and mantain airplanes and the airworthiness authoritieswho establish rules and regulations, approve the design andpromote airline maintenance performance.

  3. Radar Observations of Convective Systems from a High-Altitude Aircraft

    Science.gov (United States)

    Heymsfield, G.; Geerts, B.; Tian, L.

    1999-01-01

    Reflectivity data collected by the precipitation radar on board the tropical Rainfall Measuring Mission (TRMM) satellite, orbiting at 350 km altitude, are compared to reflectivity data collected nearly simultaneously by a doppler radar aboard the NASA ER-2 flying at 19-20 km altitude, i.e. above even the deepest convection. The TRMM precipitation radar is a scanning device with a ground swath width of 215 km, and has a resolution of about a4.4 km in the horizontal and 250 m in the vertical (125 m in the core swath 48 km wide). The TRMM radar has a wavelength of 217 cm (13.8 GHz) and the Nadir mirror echo below the surface is used to correct reflectivity for loss by attenuation. The ER-2 Doppler radar (EDOP) has two antennas, one pointing to the nadir, 34 degrees forward. The forward pointing beam receives both the normal and the cross-polarized echos, so the linear polarization ratio field can be monitored. EDOP has a wavelength of 3.12 cm (9.6 GHz), a vertical resolution of 37.5 m and a horizontal along-track resolution of about 100 m. The 2-D along track airflow field can be synthesized from the radial velocities of both beams, if a reflectivity-based hydrometer fall speed relation can be assumed. It is primarily the superb vertical resolution that distinguishes EDOP from other ground-based or airborne radars. Two experiments were conducted during 1998 into validate TRMM reflectivity data over convection and convectively-generated stratiform precipitation regions. The Teflun-A (TEXAS-Florida Underflight) experiment, was conducted in April and May and focused on mesoscale convective systems mainly in southeast Texas. TEFLUN-B was conducted in August-September in central Florida, in coordination with CAMEX-3 (Convection and Moisture Experiment). The latter was focused on hurricanes, especially during landfall, whereas TEFLUN-B concentrated on central; Florida convection, which is largely driven and organized by surface heating and ensuing sea breeze circulations

  4. Pressure breathing in fighter aircraft for G accelerations and loss of cabin pressurization at altitude--a brief review.

    Science.gov (United States)

    Lauritzsen, Lars P; Pfitzner, John

    2003-04-01

    The purpose of this brief review is to outline the past and present use of pressure breathing, not by patients but by fighter pilots. Of the historical and recent references quoted, most are from aviation-medicine journals that are not often readily available to anesthesiologists. Pressure breathing at moderate levels of airway pressure gave World War II fighter pilots a tactical altitude advantage. With today's fast and highly maneuverable jet fighters, very much higher airway pressures of the order of 8.0 kPa (identical with 60 mmHg) are used. They are used in conjunction with a counterpressure thoracic vest and an anti-G suit for the abdomen and lower body. Pressurization is activated automatically in response to +Gz accelerations, and to a potentially catastrophic loss of cabin pressurization at altitude. During +Gz accelerations, pressure breathing has been shown to maintain cerebral perfusion by raising the systemic arterial pressure, so increasing the level of G-tolerance that is afforded by the use of anti-G suits and seat tilt-back angles alone. This leaves the pilot less reliant on rigorous, and potentially distracting, straining maneuvers. With loss of cabin pressurization at altitude, pressure breathing of 100% oxygen at high airway pressures enables the pilot's alveolar PO(2) to be maintained at a safe level during emergency descent. Introduced in military aviation, pressure breathing for G-tolerance and pressure breathing for altitude presented as concepts that may be of general physiological interest to many anesthesiologists.

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

    International Nuclear Information System (INIS)

    Kubancak, J.; Ambrozova, I.; Ploc, O.; Pachnerova Brabcova, K.; Stepan, V.; Uchihori, Y.

    2014-01-01

    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 H*(10) depends on the location in the aircraft. The aim of this article is to experimentally evaluate H*(10) on-board selected types of aircraft. The authors found that H*(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. (authors)

  6. Military jet pilots have higher p-wave dispersions compared to the transport aircraft aircrew

    Directory of Open Access Journals (Sweden)

    Mustafa Çakar

    2016-08-01

    Full Text Available Objectives: For the purpose of flight safety military aircrew must be healthy. P-wave dispersion (PWD is the p-wave length difference in an electrocardiographic (ECG examination and represents the risk of developing atrial fibrillation. In the study we aimed at investigating PWD in healthy military aircrew who reported for periodical examinations. Material and Methods: Seventy-five asymptomatic military aircrew were enrolled in the study. All the subjects underwent physical, radiologic and biochemical examinations, and a 12-lead electrocardiography. P-wave dispersions were calculated. Results: The mean age of the study participants was 36.15±8.97 years and the mean p-wave duration was 100.8±12 ms in the whole group. Forty-seven subjects were non-pilot aircrew, and 28 were pilots. Thirteen study subjects were serving in jets, 49 in helicopters, and 13 were transport aircraft pilots. Thirty-six of the helicopter and 11 of the transport aircraft aircrew were non-pilot aircrew. P-wave dispersion was the lowest in the transport aircraft aircrew, and the highest in jet pilots. P-wave dispersions were similar in the pilots and non-pilot aircrew. Twenty-three study subjects were overweight, 19 had thyroiditis, 26 had hepatosteatosis, 4 had hyperbilirubinemia, 2 had hypertension, and 5 had hyperlipidemia. The PWD was significantly associated with thyroid-stimulating hormone (TSH levels. Serum uric acid levels were associated with p-wave durations. Serum TSH levels were the most important predictor of PWD. Conclusions: When TSH levels were associated with PWD, uric acid levels were associated with p-wave duration in the military aircrew. The jet pilots had higher PWDs. These findings reveal that military jet pilots may have a higher risk of developing atrial fibrillation, and PWD should be recorded during periodical examinations.

  7. Unmanned Aerial Vehicles: Progress Toward Meeting High Altitude Endurance Aircraft Price Goals

    National Research Council Canada - National Science Library

    1998-01-01

    ...) High Altitude Endurance (HAE) Unmanned Aerial Vehicle (UAV) program to determine whether the average flyaway cost for the Global Hawk and DarkStar HAE alr vehicles will be within DOD's cost goal...

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

    Science.gov (United States)

    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.

  9. Aircraft dual-shaft jet engine with indirect action fuel flow controller

    Science.gov (United States)

    Tudosie, Alexandru-Nicolae

    2017-06-01

    The paper deals with an aircraft single-jet engine's control system, based on a fuel flow controller. Considering the engine as controlled object and its thrust the most important operation effect, from the multitude of engine's parameters only its rotational speed n is measurable and proportional to its thrust, so engine's speed has become the most important controlled parameter. Engine's control system is based on fuel injection Qi dosage, while the output is engine's speed n. Based on embedded system's main parts' mathematical models, the author has described the system by its block diagram with transfer functions; furthermore, some Simulink-Matlab simulations are performed, concerning embedded system quality (its output parameters time behavior) and, meanwhile, some conclusions concerning engine's parameters mutual influences are revealed. Quantitative determinations are based on author's previous research results and contributions, as well as on existing models (taken from technical literature). The method can be extended for any multi-spool engine, single- or twin-jet.

  10. New method of calculating the power at altitude of aircraft engines equipped with superchargers on the basis of tests made under sea-level conditions

    Science.gov (United States)

    Sarracino, Marcello

    1941-01-01

    The present article deals with what is considered to be a simpler and more accurate method of determining, from the results of bench tests under approved rating conditions, the power at altitude of a supercharged aircraft engine, without application of correction formulas. The method of calculating the characteristics at altitude, of supercharged engines, based on the consumption of air, is a more satisfactory and accurate procedure, especially at low boost pressures.

  11. Nonlinear acoustic propagation of launch vehicle and military jet aircraft noise

    Science.gov (United States)

    Gee, Kent L.

    2010-10-01

    The noise from launch vehicles and high-performance military jet aircraft has been shown to travel nonlinearly as a result of an amplitude-dependent speed of sound. Because acoustic pressure compressions travel faster than rarefactions, the waveform steepens and shocks form. This process results in a very different (and readily audible) noise signature and spectrum than predicted by linear models. On-going efforts to characterize the nonlinearity using statistical and spectral measures are described with examples from recent static tests of solid rocket boosters and the F-22 Raptor.

  12. The equivalence of gravitational potential and rechargeable battery for high-altitude long-endurance solar-powered aircraft on energy storage

    International Nuclear Information System (INIS)

    Gao, Xian-Zhong; Hou, Zhong-Xi; Guo, Zheng; Fan, Rong-Fei; Chen, Xiao-Qian

    2013-01-01

    Highlights: • The scope of this paper is to apply solar energy to achieve the high-altitude long-endurance flight. • The equivalence of gravitational potential and rechargeable battery is discussed. • Four kinds of factors have been discussed to compare the two method of energy storage. • This work can provide some governing principles for the application of solar-powered aircraft. - Abstract: Applying solar energy is one of the most promising methods to achieve the aim of High-altitude Long-endurance (HALE) flight, and solar-powered aircraft is usually taken by the research groups to develop HALE aircraft. However, the crucial factor which constrains the solar-powered aircraft to achieve the aim of HALE is the problem how to fulfill the power requirement under weight constraint of rechargeable batteries. Motivated by the birds store energy from thermal by gaining height, the method of energy stored by gravitational potential for solar-powered aircraft have attracted great attentions in recent years. In order to make the method of energy stored in gravitational potential more practical in solar-powered aircraft, the equivalence of gravitational potential and rechargeable battery for aircraft on energy storage has been analyzed, and four kinds of factors are discussed in this paper: the duration of solar irradiation, the charging rate, the energy density of rechargeable battery and the initial altitude of aircraft. This work can provide some governing principles for the solar-powered aircraft to achieve the unlimited endurance flight, and the endurance performance of solar-powered aircraft may be greatly improved by the application of energy storage using gravitational potential

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  15. Compact, Lightweight, Ceramic Matrix Composite (CMC) Based Acoustic Liners for Reducing Subsonic Jet Aircraft Engine Noise

    Science.gov (United States)

    Kiser, J. Douglas; Grady, Joseph E.; Miller, Christopher J.; Hultgren, Lennart S.; Jones, Michael G.

    2016-01-01

    Recent developments have reduced fan and jet noise contributions to overall subsonic aircraft jet-engine noise. Now, aircraft designers are turning their attention toward reducing engine core noise. The NASA Glenn Research Center and NASA Langley Research Center have teamed to investigate the development of a compact, lightweight acoustic liner based on oxide/oxide ceramic matrix composite (CMC) materials. The NASA team has built upon an existing oxide/oxide CMC sandwich structure concept that provides monotonal noise reduction. Oxide/oxide composites have good high temperature strength and oxidation resistance, which could allow them to perform as core liners at temperatures up to 1000C (1832F), and even higher depending on the selection of the composite constituents. NASA has initiated the evaluation of CMC-based liners that use cells of different lengths (variable-depth channels) or effective lengths to achieve broadband noise reduction. Reducing the overall liner thickness is also a major goal, to minimize the volume occupied by the liner. As a first step toward demonstrating the feasibility of our concepts, an oxide/oxide CMC acoustic testing article with different channel lengths was tested. Our approach, summary of test results, current status, and goals for the future are reported.

  16. Energy Expenditures of Caribou Responding to Low-Altitude Jet Aircraft.

    Science.gov (United States)

    1993-09-01

    collared female caribou of the Delta Herd , 5 controls and 5 treatments (i.e., overflown), carried animal noise monitors and were overflown in April... Porcupine Caribou Model (CARIBOU), predicted that, for the sound exposures of the field study, changes in energy expenditure, forage intake, energy balance...and consequent pregnancy rate were small. Although we project no significant decrease in fecundity and thus, herd productivity in response to the

  17. A Concluding Study of the Altitude Determination Deficiencies of the Service Aircraft Instrumentation Package (SAIP)

    Science.gov (United States)

    1993-03-25

    manually . M2F=3.28083989 A=size( HTP ); TO= HTP (I,2)+273.15; PO= HTP (I,3); H0= HTP (1,1); R=287.04; GSL=9.7957; H=[]; P3=0; RAD=20820807; axis((0,5000,0,30...contributed, but I would especially like to acknowledge Bob Nagy of the Geophysics Department for his assistance in providing, and interpreting the...teet to under 250 feet at an altitude of 30,000 feet. The method does require the sounding data to be manually examined to pick out the layer. When a

  18. Determination and stabilization of the altitude of an aircraft in space using semi-conductor detectors

    International Nuclear Information System (INIS)

    Gilly, L.

    1967-01-01

    The device studied in this report can be used as altimeter or as altitude stabilizer (B.F. number PV 100-107, March 23, 1967). It includes essentially a 'surface barrier' semiconductor detector which counts alpha particles of a radioactive source. Two sources are used corresponding to two possible utilizations of the device. This report describes experiences made in laboratory which comprises electronic tests and a physic study. Systematic analysis of experimental errors is made comparatively with aneroid altimeters. An industrial device project is given. (author) [fr

  19. Chasing the Great American 2017 Total Solar Eclipse: Coronal Results from NASA's WB-57F High-Altitude Research Aircraft

    Science.gov (United States)

    Caspi, A.; Tsang, C.; DeForest, C. E.; Seaton, D. B.; Bryans, P.; Burkepile, J.; Casey, T. A.; Collier, J.; Darrow, D.; DeLuca, E.; Durda, D. D.; Gallagher, P.; Golub, L.; Judge, P. G.; Laurent, G. T.; Lewis, J.; Mallini, C.; Parent, T.; Propp, T.; Steffl, A.; Tomczyk, S.; Warner, J.; West, M. J.; Wiseman, J.; Zhukov, A.

    2017-12-01

    Total solar eclipses present rare opportunities to study the complex solar corona, down to altitudes of just a few percent of a solar radius above the surface, using ground-based and airborne observatories that would otherwise be dominated by the intense solar disk and high sky brightness. Studying the corona is critical to gaining a better understanding of physical processes that occur on other stars and astrophysical objects, as well as understanding the dominant driver of space weather that affects human assets at Earth and elsewhere. For example, it is still poorly understood how the corona is heated to temperatures of 1-2 MK globally and up to 5-10 MK above active regions, while the underlying chromosphere is 100 times cooler; numerous theories abound, but are difficult to constrain due to the limited sensitivities and cadences of prior measurements. The origins and stability of coronal fans, and the extent of their reach to the middle and outer corona, are also not well known, limited in large part by sensitivities and fields of view of existing observations. Airborne observations during the eclipse provide unique advantages; by flying in the stratosphere at altitudes of 50 kft or higher, they avoid all weather, the seeing quality is enormously improved, and additional wavelengths such as near- IR also become available due to significantly reduced water absorption. For an eclipse, an airborne observatory can also follow the shadow, increasing the total observing time by 50% or more. We present results of solar coronal measurements from airborne observations of the 2017 Great American Total Solar Eclipse using two of NASA's WB-57 high-altitude research aircraft, each equipped with two 8.7" telescopes feeding high-sensitivity visible (green-line) and medium-wave IR (3-5 μm) cameras operating at high cadence (30 Hz) with 3 arcsec/pixel platescale and ±3 R_sun fields of view. The aircraft flew along the eclipse path, separated by 110 km, to observe a summed 7

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

    Science.gov (United States)

    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

  1. Modeling energy and reproductive costs in caribou exposed to low flying military jet aircraft

    Directory of Open Access Journals (Sweden)

    B.R. Luick

    1996-01-01

    Full Text Available We used simulation modeling to estimate the effect of low-flying military jet aircraft on the productivity of caribou. The base model (CARIBOU, CWS Whitehorse, Yukon Territory uses daily intake and expenditure of energy to assess the condition of female caribou throughout the annual cycle. The activity budget of the model caribou was adjusted based on field observations of responses to noise disturbance. A subroutine was added that predicted the likelihood of conception based on fall body fat weight. Caribou responses to overflights were evaluated by equipping free-ranging caribou with radio collars and activity sensors that could distinguish between resting and active periods. Collared animals were exposed to 110 overflights by A-10, F-15 and F- 16 jet aircraft during late-winter, post-calving and the insect season. Noise exposure levels for individual animals either were measured directly with collar-mounted dosimeters or were estimated based on the proximity of the caribou to the aircraft during the overflight. A Time-averaged Sound Level (LT was calculated from the total daily noise exposure for each animal and linear regression was used to evaluate the influence of daily noise exposure on daily hours spent resting. Results of these analyses then were used to modify the time budgets in the CARIBOU model. That is, if time spent resting declined, then time spent in the two rest classes (lying and standing were proportionately redistributed into the three active classes (foraging, walking and running. Model simulations indicated that caribou increased forage intake in response to increased noise exposure, but it also predicted that increased noise exposure would cause a reduced accumulation of body fat. Because body fat in fall has successfully been used to predict the probability of pregnancy (see Gerhart et al, 1993, this relationship was used in the model. Preliminary model simulations indicate that increased noise exposure decreases the

  2. Mathematical model of an indirect action fuel flow controller for aircraft jet engines

    Science.gov (United States)

    Tudosie, Alexandru-Nicolae

    2017-06-01

    The paper deals with a fuel mass flow rate controller with indirect action for aircraft jet engines. The author has identified fuel controller's main parts and its operation mode, then, based on these observations, one has determined motion equations of each main part, which have built system's non-linear mathematical model. In order to realize a better study this model was linearised (using the finite differences method) and then adimensionalized. Based on this new form of the mathematical model, after applying Laplace transformation, the embedded system (controller+engine) was described by the block diagram with transfer functions. Some Simulink-Matlab simulations were performed, concerning system's time behavior for step input, which lead to some useful conclusions and extension possibilities.

  3. Planetary Science from NASA's WB-57 Canberra High Altitude Research Aircraft During the Great American Eclipse of 2017

    Science.gov (United States)

    Tsang, C.; Caspi, A.; DeForest, C. E.; Durda, D. D.; Steffl, A.; Lewis, J.; Wiseman, J.; Collier, J.; Mallini, C.; Propp, T.; Warner, J.

    2017-12-01

    The Great American Eclipse of 2017 provided an excellent opportunity for heliophysics research on the solar corona and dynamics that encompassed a large number of research groups and projects, including projects flown in the air and in space. Two NASA WB-57F Canberra high altitude research aircraft were launched from NASA's Johnson Space Center, Ellington Field into the eclipse path. At an altitude of 50,000ft, and outfitted with visible and near-infrared cameras, these aircraft provided increased duration of observations during eclipse totality, and much sharper images than possible on the ground. Although the primary mission goal was to study heliophysics, planetary science was also conducted to observe the planet Mercury and to search for Vulcanoids. Mercury is extremely challenging to study from Earth. The 2017 eclipse provided a rare opportunity to observe Mercury under ideal astronomical conditions. Only a handful of near-IR thermal images of Mercury exist, but IR images provide critical surface property (composition, albedo, porosity) information, essential to interpreting lower resolution IR spectra. Critically, no thermal image of Mercury currently exists. By observing the nightside surface during the 2017 Great American Eclipse, we aimed to measure the diurnal temperature as a function of local time (longitude) and attempted to deduce the surface thermal inertia integrated down to a few-cm depth below the surface. Vulcanoids are a hypothesized family of asteroids left over from the formation of the solar system, in the dynamically stable orbits between the Sun and Mercury at 15-45 Rs (4-12° solar elongation). Close proximity to the Sun, plus their small theoretical sizes, make Vulcanoid searches rare and difficult. The 2017 eclipse was a rare opportunity to search for Vulcanoids. If discovered these unique, highly refractory and primordial bodies would have a significant impact on our understanding of solar system formation. Only a handful of deep

  4. Vertical Cloud Climatology During TC4 Derived from High-Altitude Aircraft Merged Lidar and Radar Profiles

    Science.gov (United States)

    Hlavka, Dennis; Tian, Lin; Hart, William; Li, Lihua; McGill, Matthew; Heymsfield, Gerald

    2009-01-01

    Aircraft lidar works by shooting laser pulses toward the earth and recording the return time and intensity of any of the light returning to the aircraft after scattering off atmospheric particles and/or the Earth s surface. The scattered light signatures can be analyzed to tell the exact location of cloud and aerosol layers and, with the aid of a few optical assumptions, can be analyzed to retrieve estimates of optical properties such as atmospheric transparency. Radar works in a similar fashion except it sends pulses toward earth at a much larger wavelength than lidar. Radar records the return time and intensity of cloud or rain reflection returning to the aircraft. Lidar can measure scatter from optically thin cirrus and aerosol layers whose particles are too small for the radar to detect. Radar can provide reflection profiles through thick cloud layers of larger particles that lidar cannot penetrate. Only after merging the two instrument products can accurate measurements of the locations of all layers in the full atmospheric column be achieved. Accurate knowledge of the vertical distribution of clouds is important information for understanding the Earth/atmosphere radiative balance and for improving weather/climate forecast models. This paper describes one such merged data set developed from the Tropical Composition, Cloud and Climate Coupling (TC4) experiment based in Costa Rica in July-August 2007 using the nadir viewing Cloud Physics Lidar (CPL) and the Cloud Radar System (CRS) on board the NASA ER-2 aircraft. Statistics were developed concerning cloud probability through the atmospheric column and frequency of the number of cloud layers. These statistics were calculated for the full study area, four sub-regions, and over land compared to over ocean across all available flights. The results are valid for the TC4 experiment only, as preferred cloud patterns took priority during mission planning. The TC4 Study Area was a very cloudy region, with cloudy

  5. Reliability analysis of nuclear containment without metallic liners against jet aircraft crash

    Energy Technology Data Exchange (ETDEWEB)

    Siddiqui, N.A.; Iqbal, M.A.; Abbas, H. E-mail: abbas_husain@hotmail.com; Paul, D.K

    2003-09-01

    The present study presents a methodology for detailed reliability analysis of nuclear containment without metallic liners against aircraft crash. For this purpose, a nonlinear limit state function has been derived using violation of tolerable crack width as failure criterion. This criterion has been considered as failure criterion because radioactive radiations may come out if size of crack becomes more than the tolerable crack width. The derived limit state uses the response of containment that has been obtained from a detailed dynamic analysis of nuclear containment under an impact of a large size Boeing jet aircraft. Using this response in conjunction with limit state function, the reliabilities and probabilities of failures are obtained at a number of vulnerable locations employing an efficient first-order reliability method (FORM). These values of reliability and probability of failure at various vulnerable locations are then used for the estimation of conditional and annual reliabilities of nuclear containment as a function of its location from the airport. To study the influence of the various random variables on containment reliability the sensitivity analysis has been performed. Some parametric studies have also been included to obtain the results of field and academic interest.

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

    Science.gov (United States)

    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.

  7. Investigation of thermoelastic stresses induced at high altitudes on aircraft external fuel tanks

    Science.gov (United States)

    Mousseau, Stephanie Lynn Steber

    As composite technology has grown over the past several decades, the use of composite materials in military applications has become more feasible and widely accepted. Although composite materials provide many benefits, including strength optimization and reduced weight, damage and repair of these materials creates an additional challenge, especially when operating in a marine environment, such as on a carrier deck. This is evident within the Navy, as excessive damage often leads to the scrapping of F/A-18 External Fuel Tanks. This damage comes in many forms, the most elusive of which is delamination. Often the delamination found on the tanks is beyond repairable limits and the cause unknown, making it difficult to predict and prevent. The purpose of this investigation was to study the structure of the Navy's 330 gallon External Fuel Tanks and investigate one potential cause of delamination, stresses induced at high altitudes by cold temperatures. A stress analysis was completed using finite element software, and validation of the model was accomplished through testing of a scale model specimen. Due to the difficulties in modeling and predicting delamination, such as unknown presence of voids and understanding failure criteria, delamination was not modeled in Abaqus, rather stresses were observed and characteristics were studied to understand the potential for delamination within the layup. In addition, studies were performed to understand the effect of material properties and layup sequence on the stress distribution within the tank. Alternative design solutions are presented which could reduce the radial stresses within the tank, and recommendations are made for further study to understand the trade-offs between stress, cost, and manufacturability.

  8. Flight Characteristics Analysis Based on QAR Data of a Jet Transport During Landing at a High-altitude Airport

    Institute of Scientific and Technical Information of China (English)

    C. Edward Lan; WU Kaiyuan; YU Jiang

    2012-01-01

    Flight data of a twin-jet transport aircraft in revenue flight are analyzed for potential safety problems.Data from the quick access recorder (QAR) are first filtered through the kinematic compatibility analysis.The filtered data are then organized into longitudinal- and lateral-directional aerodynamic model data with dynamic ground effect.The dynamic ground effect requires the radio height and sink rate in the models.The model data ere then refined into numerical models through a funzzy logic algorithm without data smoothing in advance.These numerical models describe nonlinear and unsteady aerodynamics and are used in nonlinear flight dynamics simulation.For the jet transport under study,it is found that the effect of crosswind is significant enough to excite the Dutch roll motion.Through a linearized analysis in flight dynamics at every instant of time,the Dutch roll motion is found to be in nonlinear oscillation without clear damping of the amplitude.In the analysis,all stability derivatives vary with time and hence are nonlinear functions of state variables.Since the Dutch roll motion is not damped despite the fact that a full-time yaw damper is engaged,it is concluded that the design data for the yaw damper is not sufficiendy realistic and the contribution of time derivative of sideslip angle to damping should be considered.As a result of nonlinear flight simulation,the vertical wind acting on the aircrafl is estimated to be mostly updraft which varies along the flight path before touchdown.Varying updraft appears to make the descent rate more difficult to control to result in a higher g-load at touchdown.

  9. Evaluating remotely sensed plant count accuracy with differing unmanned aircraft system altitudes, physical canopy separations, and ground covers

    Science.gov (United States)

    Leiva, Josue Nahun; Robbins, James; Saraswat, Dharmendra; She, Ying; Ehsani, Reza

    2017-07-01

    This study evaluated the effect of flight altitude and canopy separation of container-grown Fire Chief™ arborvitae (Thuja occidentalis L.) on counting accuracy. Images were taken at 6, 12, and 22 m above the ground using unmanned aircraft systems. Plants were spaced to achieve three canopy separation treatments: 5 cm between canopy edges, canopy edges touching, and 5 cm of canopy edge overlap. Plants were placed on two different ground covers: black fabric and gravel. A counting algorithm was trained using Feature Analyst®. Total counting error, false positives, and unidentified plants were reported for images analyzed. In general, total counting error was smaller when plants were fully separated. The effect of ground cover on counting accuracy varied with the counting algorithm. Total counting error for plants placed on gravel (-8) was larger than for those on a black fabric (-2), however, false positive counts were similar for black fabric (6) and gravel (6). Nevertheless, output images of plants placed on gravel did not show a negative effect due to the ground cover but was impacted by differences in image spatial resolution.

  10. Ecological Risk Assessment Framework for Low-Altitude Overflights by Fixed-Wing and Rotary-Wing Military Aircraft

    Energy Technology Data Exchange (ETDEWEB)

    Efroymson, R.A.

    2001-01-12

    This is a companion report to the risk assessment framework proposed by Suter et al. (1998): ''A Framework for Assessment of Risks of Military Training and Testing to Natural Resources,'' hereafter referred to as the ''generic framework.'' The generic framework is an ecological risk assessment methodology for use in environmental assessments on Department of Defense (DoD) installations. In the generic framework, the ecological risk assessment framework of the US Environmental Protection Agency (EPA 1998) is modified for use in the context of (1) multiple and diverse stressors and activities at a military installation and (2) risks resulting from causal chains, e.g., effects on habitat that indirectly impact wildlife. Both modifications are important if the EPA framework is to be used on military installations. In order for the generic risk assessment framework to be useful to DoD environmental staff and contractors, the framework must be applied to specific training and testing activities. Three activity-specific ecological risk assessment frameworks have been written (1) to aid environmental staff in conducting risk assessments that involve these activities and (2) to guide staff in the development of analogous frameworks for other DoD activities. The three activities are: (1) low-altitude overflights by fixed-wing and rotary-wing aircraft (this volume), (2) firing at targets on land, and (3) ocean explosions. The activities were selected as priority training and testing activities by the advisory committee for this project.

  11. Investigation of the I-40 Jet-Propulsion Engine in the Cleveland Altitude Wind Tunnel. V - Operational Characteristics. 5; Operational Characteristics

    Science.gov (United States)

    Golladay, Richard L.; Gendler, Stanley L.

    1947-01-01

    An investigation has been conducted in the Cleveland altitude wind tunnel to determine the operational characteristics of the I-40 jet-propulsion engine over a range of pressure altitudes from 10,000 to 50,000 feet and ram-pressure ratios from 1.00 to 1.76. Engine operational data were obtained with the engine in the standard configuration and with various modifications of the fuel system, the electrical system, and the combustion chambers. The effects of altitude and airspeed on operating speed range, starting, windmilli.ng, acceleration, speed regulation, cooling, and vibration of the standard and modified engines were determined, and damage to parts was noted. Maximum engine speed was obtainable at all altitudes and airspeeds wi th each fuel-control system investigated. The minimum idling speed was raised by increases in altitude and airspeed. The lowest minimum stable speeds were obtained with the standard configuration using 40-gallon nozzles with individual metering plugs. The engine was started normally at altitudes as high as 20,000 feet with all of the fuel systems and ignition combinations except one. Ignition at 70,000 feet was difficult and, although successful ignition occurred, acceleration was slow and usually characterized by excessive tail-pipe temperature. During windmilling investigations of the engine equipped with the standard fuel system, the engine could not be started at ram-pressure ratios of 1.1 to 1.7 at altitudes of 10,000, 20,000 and 30,000 feet. When equipped with the production barometric and Monarch 40-gallon nozzles, the engine accelerated in 12 seconds from an engine speed of 6000 rpm to 11,000 rpm at 20,000 feet and an average tail-pipe temperature of 11000 F. At the same altitude and temperature, all the engine configurations had approximately the same rate of acceleration. The Woodward governor produced the safest accelerations, inasmuch as it could be adjusted to automatically prevent acceleration blow out. The engine speed was

  12. Design and simulation of solar powered aircraft for year-round operation at high altitude; Auslegung und Simulation von hochfliegenden, dauerhaft stationierbaren Solardrohnen

    Energy Technology Data Exchange (ETDEWEB)

    Keidel, B.

    2000-05-18

    An unmanned solar powered aircraft configuration called SOLITAIR has been designed. This aircraft is intended to be used as an high altitude long endurance (HALE) sensor platform for year-round operation at intermediate latitudes up to about {+-}55 . For the design studies leading to this aircraft configuration, a software package has been developed which enables an effective design and a proper simulation of the entire solar aircraft system for various flight missions. The performance analysis and the mission simulation showed, that a configuration with large additional solar panels, that can be tilted in order to follow the sun angle during daytime operation appears to be superior to aircraft configurations with wing-mounted solar cells for the desired operational area. In order to examine the basic flight characteristics of the SOLITAIR configuration a remote controlled demonstration model has been built and test flown. [German] In der vorliegenden Arbeit wurden Moeglichkeiten geschaffen, um Gesamtsystemkonfigura-tionen unbemannter hochfliegender Solarflugzeuge fuer unterschiedliche Anwendungsfaelle auszulegen und die Flugleistungen sowie die Missionsfaehigkeit dieser Konfigurationen aufzuzeigen. Mit den geschaffenen und verifizierten Entwicklungswerkzeugen wurde eine Solarflugzeugkonfiguration entworfen und mittels eines Demonstrationsmodells erprobt. Mit dieser Konfiguration kann eine dauerhafte Stationierbarkeit von ca. 55 suedlicher bis 55 noerdlicher Breite erreicht werden. Dies stellt eine bedeutende Erweiterung des bisher fuer moeglich gehaltenen Nutzungsbereiches solcher Flugzeuge dar.

  13. NASA Jet Noise Research

    Science.gov (United States)

    Henderson, Brenda

    2016-01-01

    The presentation highlights NASA's jet noise research for 2016. Jet-noise modeling efforts, jet-surface interactions results, acoustic characteristics of multi-stream jets, and N+2 Supersonic Aircraft system studies are presented.

  14. Breeding for Increased Water Use Efficiency in Corn (Maize) Using a Low-altitude Unmanned Aircraft System

    Science.gov (United States)

    Shi, Y.; Veeranampalayam-Sivakumar, A. N.; Li, J.; Ge, Y.; Schnable, J. C.; Rodriguez, O.; Liang, Z.; Miao, C.

    2017-12-01

    Low-altitude aerial imagery collected by unmanned aircraft systems (UAS) at centimeter-level spatial resolution provides great potential to collect high throughput plant phenotyping (HTP) data and accelerate plant breeding. This study is focused on UAS-based HTP for breeding increased water use efficiency in corn in eastern Nebraska. The field trail is part of an effort by the Genomes to Fields consortium effort to grow and phenotype many of the same corn (maize) hybrids at approximately 40 locations across the United States and Canada in order to stimulate new research in crop modeling, the development of new plant phenotyping technologies and the identification of genetic loci that control the adaptation of specific corn (maize) lines to specific environments. It included approximately 250 maize hybrids primary generated using recently off patent material from major seed companies. These lines are the closest material to what farmers are growing today which can be legally used for research purposes and genotyped by the public sector. During the growing season, a hexacopter equipped with a multispectral and a RGB cameras was flown and used to image this 1-hectare field trial near Mead, NE. Sensor data from the UAS were correlated directly with grain yield, measured at the end of the growing season, and were also be used to quantify other traits of interest to breeders including flowering date, plant height, leaf orientation, canopy spectral, and stand count. The existing challenges of field data acquisition (to ensure data quality) and development of effective image processing algorithms (such as detecting corn tassels) will be discussed. The success of this study and others like it will speed up the process of phenotypic data collection, and provide more accurate and detailed trait data for plant biologists, plant breeders, and other agricultural scientists. Employing advanced UAS-based machine vision technologies in agricultural applications have the potential

  15. Process for Refining and Validating a Finite Element Model of an Experimental High-Altitude, Long-Endurance (HALE) Aircraft

    Science.gov (United States)

    2011-06-01

    7 Figure 4. Helios flying near the Hawaiian islands of Niihau and Lehua [15] ................... 8 Figure 5. Plan view of ERAST Program aircraft...Figure 4. Helios flying near the Hawaiian islands of Niihau and Lehua [15] 9 Figure 5. Plan view of ERAST Program aircraft

  16. Creation of a Dynamical Stratospheric Turbulence Forecasting and Nowcasting Tool for High Altitude Airships and Other Aircraft

    National Research Council Canada - National Science Library

    Fritts, David C

    2008-01-01

    ... for which significant wave and turbulence activity may pose an operational or functional risk. The specific goal for MDA purposes was to create a forecasting methodology for turbulence activity at the expected High Altitude Airship (HAA...

  17. Altitude-Wind-Tunnel Investigation of the 19B-2, 19B-8 and 19XB-1 Jet- Propulsion Engines. 4; Analysis of Compressor Performance

    Science.gov (United States)

    Dietz, Robert O.; Kuenzig, John K.

    1947-01-01

    Investigations were conducted in the Cleveland altitude wind tunnel to determine the performance and operational characteristics of the 19B-2, 19B-8, and 19XS-1 turbojet engines. One objective was to determine the effect of altitude, flight Mach number, and tail-pipe-nozzle area on the performance characteristics of the six-stage and ten-stage axial-flow compressors of the 19B-8 and 19XB-1 engines, respectively, The data were obtained over a range of simulated altitudes and flight Mach numbers. At each simulated flight condition the engine was run over its full operable range of speeds. Performance characteristics of the 19B-8 and 19XB-1 compressors for the range of operation obtainable in the turboJet-engine installation are presented. Compressor characteristics are presented as functions of air flow corrected to sea-level conditions, compressor Mach number, and compressor load coefficient. For the range of compressor operation investigated, changes in Reynolds number had no measurable effect on the relations among compressor Mach number, corrected air flow, compressor load coefficient, compressor pressure ratio, and compressor efficiency. The operating lines for the 19B-8 compressor lay on the low-air-flow side of the region of maximum compressor efficiency; the 19B-8 compressor operated at higher average pressure coefficients per stage and produced a lower over-all pressure ratio than did the 19XB-1 compressor.

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

    Science.gov (United States)

    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.

  19. THE KINETICS OF CONTAMINANTS ACCUMULATION IN THE JET FUEL DURING THE TECHNOLOGICAL PROCESS OF ITS PREPARATION FOR AIRCRAFT REFUELING

    Directory of Open Access Journals (Sweden)

    A. A. Brailko

    2017-01-01

    Full Text Available Much attention is payed to the tasks for ensuring domestic and international aircraft safety and regularity, which are multifaceted and complex. One of them is the system of ensuring the quality of aviation fuel for refueling aircraft at airports. A significant influence of the quality, chemical composition and fuel range on the reliability and lifetime of components and parts of the aircraft fuel system was studied in the process of development and experience accumulation of aircraft operating, processes of aviation fuel production, as well as during storage, quality control, transportation, refueling preparation and aircraft refueling. Currently, work is being done to study the influence of fuel quality on the units of the technological scheme of fuel-filling complexes, which provide the required cleanliness of the fuel according to the regulations. The article describes the trend level of aviation fuel cleanliness at the stages from receipt to issuance to the refueling station. The evaluation of compliance with existing regulations on the level of jet fuel cleanliness and the efficiency of fuel cleaning facilities is carried out. It is stated that one of the problems of insufficient level of aviation fuel cleaning quality is a violation of the acceptable contamination level of the fuel before the filter. It was found that the disadvantage of the used filter paper is the fiber wash out process. According to this research it was found that while cleaning fuel from mechanical admixtures it is necessary to take into account the technical condition of the filtering element, and proposal was developed for fuel-filling systems to ensure aviation fuel cleanliness in compliance with regulations.

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

    Science.gov (United States)

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

    2009-09-01

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

  1. Exposures to jet fuel and benzene during aircraft fuel tank repair in the U.S. Air Force.

    Science.gov (United States)

    Carlton, G N; Smith, L B

    2000-06-01

    Jet fuel and benzene vapor exposures were measured during aircraft fuel tank entry and repair at twelve U.S. Air Force bases. Breathing zone samples were collected on the fuel workers who performed the repair. In addition, instantaneous samples were taken at various points during the procedures with SUMMA canisters and subsequent analysis by mass spectrometry. The highest eight-hour time-weighted average (TWA) fuel exposure found was 1304 mg/m3; the highest 15-minute short-term exposure was 10,295 mg/m3. The results indicate workers who repair fuel tanks containing explosion suppression foam have a significantly higher exposure to jet fuel as compared to workers who repair tanks without foam (p fuel, absorbed by the foam, to volatilize during the foam removal process. Fuel tanks that allow flow-through ventilation during repair resulted in lower exposures compared to those tanks that have only one access port and, as a result, cannot be ventilated efficiently. The instantaneous sampling results confirm that benzene exposures occur during fuel tank repair; levels up to 49.1 mg/m3 were found inside the tanks during the repairs. As with jet fuel, these elevated benzene concentrations were more likely to occur in foamed tanks. The high temperatures associated with fuel tank repair, along with the requirement to wear vapor-permeable cotton coveralls for fire reasons, could result in an increase in the benzene body burden of tank entrants.

  2. Statistical summary of commercial jet aircraft accidents : worldwide operations, 1959-2009

    Science.gov (United States)

    2010-07-01

    The accident statistics presented in this summary are confined to worldwide commercial jet airplanes that are heavier than 60,000 pounds maximum gross weight. Within that set of airplanes, there are two groups excluded: : 1) Airplanes manufactured in...

  3. Unmanned Aircraft System (UAS) Traffic Management (UTM): Enabling Civilian Low-Altitude Airspace and Unmanned Aerial System Operations

    Science.gov (United States)

    Kopardekar, Parimal Hemchandra

    2016-01-01

    Just a year ago we laid out the UTM challenges and NASA's proposed solutions. During the past year NASA's goal continues to be to conduct research, development and testing to identify airspace operations requirements to enable large-scale visual and beyond visual line-of-sight UAS operations in the low-altitude airspace. Significant progress has been made, and NASA is continuing to move forward.

  4. ERBS fuel addendum: Pollution reduction technology program small jet aircraft engines, phase 3

    Science.gov (United States)

    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.

  5. The NASA Pollution-Reduction Technology Program for small jet aircraft engines - A status report

    Science.gov (United States)

    Fear, J. S.

    1976-01-01

    A three-phase experimental program is described which has the objective of enabling EPA Class T1 jet engines to meet the 1979 EPA emissions standards. In Phase I, three advanced combustor concepts, designed for the AiResearch TFE 731-2 turbofan engine, were evaluated in screening tests. Goals for carbon monoxide and unburned hydrocarbons were met or closely approached with two of the concepts with relatively modest departures from conventional combustor design practices. A more advanced premixing/prevaporizing combustor, while appearing to have the potential for meeting the oxides of nitrogen goal as well, will require extensive development to make it a practical combustion system. Smoke numbers for the two combustor concepts which will be carried forward into Phase II of the program were well within the EPA smoke standard. Phase II, Combustor-Engine Compatibility Testing, which is in its early stages, and planned Phase III, Combustor-Engine Demonstration Testing, are also described.

  6. Synthetic Jet Actuator-Based Aircraft Tracking Using a Continuous Robust Nonlinear Control Strategy

    Directory of Open Access Journals (Sweden)

    N. Ramos-Pedroza

    2017-01-01

    Full Text Available A robust nonlinear control law that achieves trajectory tracking control for unmanned aerial vehicles (UAVs equipped with synthetic jet actuators (SJAs is presented in this paper. A key challenge in the control design is that the dynamic characteristics of SJAs are nonlinear and contain parametric uncertainty. The challenge resulting from the uncertain SJA actuator parameters is mitigated via innovative algebraic manipulation in the tracking error system derivation along with a robust nonlinear control law employing constant SJA parameter estimates. A key contribution of the paper is a rigorous analysis of the range of SJA actuator parameter uncertainty within which asymptotic UAV trajectory tracking can be achieved. A rigorous stability analysis is carried out to prove semiglobal asymptotic trajectory tracking. Detailed simulation results are included to illustrate the effectiveness of the proposed control law in the presence of wind gusts and varying levels of SJA actuator parameter uncertainty.

  7. Design and analysis of annular combustion chamber of a low bypass turbofan engine in a jet trainer aircraft

    Directory of Open Access Journals (Sweden)

    C. Priyant Mark

    2016-06-01

    Full Text Available The design of an annular combustion chamber in a gas turbine engine is the backbone of this paper. It is specifically designed for a low bypass turbofan engine in a jet trainer aircraft. The combustion chamber is positioned in between the compressor and turbine. It has to be designed based on the constant pressure, enthalpy addition process. The present methodology deals with the computation of the initial design parameters from benchmarking of real-time industry standards and arriving at optimized values. It is then studied for feasibility and finalized. Then the various dimensions of the combustor are calculated based on different empirical formulas. The air mass flow is then distributed across the zones of the combustor. The cooling requirement is met using the cooling holes. Finally the variations of parameters at different points are calculated. The whole combustion chamber is modeled using Siemens NX 8.0, a modeling software and presented. The model is then analyzed using various parameters at various stages and levels to determine the optimized design. The aerodynamic flow characteristics is simulated numerically by means of ANSYS 14.5 software suite. The air-fuel mixture, combustion-turbulence, thermal and cooling analysis is carried out. The analysis is performed at various scenarios and compared. The results are then presented in image outputs and graphs.

  8. High Altitude Long Endurance Remotely Operated Aircraft - National Airspace System Integration - Simulation IPT: Detailed Airspace Operations Simulation Plan. Version 1.0

    Science.gov (United States)

    2004-01-01

    The primary goal of Access 5 is to allow safe, reliable and routine operations of High Altitude-Long Endurance Remotely Operated Aircraft (HALE ROAs) within the National Airspace System (NAS). Step 1 of Access 5 addresses the policies, procedures, technologies and implementation issues of introducing such operations into the NAS above pressure altitude 40,000 ft (Flight Level 400 or FL400). Routine HALE ROA activity within the NAS represents a potentially significant change to the tasks and concerns of NAS users, service providers and other stakeholders. Due to the complexity of the NAS, and the importance of maintaining current high levels of safety in the NAS, any significant changes must be thoroughly evaluated prior to implementation. The Access 5 community has been tasked with performing this detailed evaluation of routine HALE-ROA activities in the NAS, and providing to key NAS stakeholders a set of recommended policies and procedures to achieve this goal. Extensive simulation, in concert with a directed flight demonstration program are intended to provide the required supporting evidence that these recommendations are based on sound methods and offer a clear roadmap to achieving safe, reliable and routine HALE ROA operations in the NAS. Through coordination with NAS service providers and policy makers, and with significant input from HALE-ROA manufacturers, operators and pilots, this document presents the detailed simulation plan for Step 1 of Access 5. A brief background of the Access 5 project will be presented with focus on Steps 1 and 2, concerning HALE-ROA operations above FL400 and FL180 respectively. An overview of project management structure follows with particular emphasis on the role of the Simulation IPT and its relationships to other project entities. This discussion will include a description of work packages assigned to the Simulation IPT, and present the specific goals to be achieved for each simulation work package, along with the associated

  9. THE KINETICS OF CONTAMINANTS ACCUMULATION IN THE JET FUEL DURING THE TECHNOLOGICAL PROCESS OF ITS PREPARATION FOR AIRCRAFT REFUELING

    OpenAIRE

    A. A. Brailko

    2017-01-01

    Much attention is payed to the tasks for ensuring domestic and international aircraft safety and regularity, which are multifaceted and complex. One of them is the system of ensuring the quality of aviation fuel for refueling aircraft at airports. A significant influence of the quality, chemical composition and fuel range on the reliability and lifetime of components and parts of the aircraft fuel system was studied in the process of development and experience accumulation of aircraft operati...

  10. Development of a portable micro-environmental cell for the testing of neutron bubble detectors in a simulated jet-aircraft environment

    International Nuclear Information System (INIS)

    Tume, P.; Bennett, L.G.I.; Lewis, B.J.; Wieland, H.K.; Reid, M.K.; Cousins, T.

    1998-01-01

    Neutron-sensitive bubble detectors were chosen as a primary detection tool to survey the dose equivalent received by aircrew exposed to natural radiation. As part of the qualification criterion, a novel micro-environmental cell was designed, assembled and tested. This apparatus is capable of simulating the climate, i.e., pressure, temperature and relative humidity, inside a jet aircraft while irradiating bubble detectors in-situ. The cell environment was manipulated using an on-line control and data acquisition system developed using LabView software. (author)

  11. Altitude exposures during commercial flight: a reappraisal.

    Science.gov (United States)

    Hampson, Neil B; Kregenow, David A; Mahoney, Anne M; Kirtland, Steven H; Horan, Kathleen L; Holm, James R; Gerbino, Anthony J

    2013-01-01

    Hypobaric hypoxia during commercial air travel has the potential to cause or worsen hypoxemia in individuals with pre-existing cardiopulmonary compromise. Knowledge of cabin altitude pressures aboard contemporary flights is essential to counseling patients accurately about flying safety. The objective of the study was to measure peak cabin altitudes during U.S. domestic commercial flights on a variety of aircraft. A handheld mountaineering altimeter was carried by the investigators in the plane cabin during commercial air travel and peak cabin altitude measured. The values were then compared between aircraft models, aircraft classes, and distances flown. The average peak cabin altitude on 207 flights aboard 17 different aircraft was 6341 +/- 1813 ft (1933 m +/- 553 m), significantly higher than when measured in a similar fashion in 1988. Peak cabin altitude was significantly higher for flights longer than 750 mi (7085 +/- 801 ft) compared to shorter flights (5160 +/- 2290 ft/1573 +/- 698 m). Cabin altitude increased linearly with flight distance for flights up to 750 mi in length, but was independent of flight distance for flights exceeding 750 mi. Peak cabin altitude was less than 5000 ft (1524 m) in 70% of flights shorter than 500 mi. Peak cabin altitudes greater than 8000 ft (2438 m) were measured on approximately 10% of the total flights. Peak cabin altitude on commercial aircraft flights has risen over time. Cabin altitude is lower with flights of shorter distance. Physicians should take these factors into account when determining an individual's need for supplemental oxygen during commercial air travel.

  12. Measurement of the energy spectrum of cosmic-ray induced neutrons aboard an ER-2 high-altitude airplane

    CERN Document Server

    Goldhagen, P E; Kniss, T; Reginatto, M; Singleterry, R C; Van Steveninck, W; Wilson, J W

    2002-01-01

    Crews working on present-day jet aircraft are a large occupationally exposed group with a relatively high average effective dose from galactic cosmic radiation. Crews of future high-speed commercial aircraft flying at higher altitudes would be even more exposed. To help reduce the significant uncertainties in calculations of such exposures, the atmospheric ionizing radiation (AIR) project, an international collaboration of 15 laboratories, made simultaneous radiation measurements with 14 instruments on five flights of a NASA ER-2 high-altitude aircraft. The primary AIR instrument was a highly sensitive extended-energy multisphere neutron spectrometer with lead and steel shells placed within the moderators of two of its 14 detectors to enhance response at high energies. Detector responses were calculated for neutrons and charged hadrons at energies up to 100 GeV using MCNPX. Neutron spectra were unfolded from the measured count rates using the new MAXED code. We have measured the cosmic-ray neutron spectrum (t...

  13. Numerical and experimental study of the mixture of engine jets in the wake vortices of an airline aircraft; Etude numerique et experimentale du melange des jets de moteur dans les tourbillons de sillage d'un avion de ligne

    Energy Technology Data Exchange (ETDEWEB)

    Brunet, St.

    1999-07-01

    This study is a contribution to the understanding of the formation and duration of aircraft condensation trails. The development of a numerical code based on the direct resolution of the 3-D compressible Navier-Stokes equations has been done first. Then, an experiment has been carried out in a wind tunnel to analyze the problem of the mixture of heated jets in a wing wake. A first validation of the numerical method has been carried out from bibliographic results and measurements of the mixture evolution of an inert tracer contained in the engine jets during a flight test. In order to characterize the condensation inside the wake, the evolution of the local water vapor saturation ratio has been calculated. The influence of the Crow instability on the mixture of effluents in the high atmosphere is also shown. Finally, a comparison is made between the numerical simulation results and the experimental measurements obtained in this study. The numerical results have also permitted to characterize the low scale exchange mechanisms between a turbulent jet and a swirl flow. (J.S.)

  14. Aircraft Fuel Cell Power Systems

    Science.gov (United States)

    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

  15. Altitude Lab

    Data.gov (United States)

    Federal Laboratory Consortium — The Altitude Lab evaluates the performance of complete oxygen systems operated in individually controlled hypobaric chambers, which duplicate pressures that would be...

  16. Determination and stabilization of the altitude of an aircraft in space using semi-conductor detectors; Determination et stabilisation de l'altitude d'un aeronef par detecteur a semiconducteur

    Energy Technology Data Exchange (ETDEWEB)

    Gilly, L. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1967-07-01

    The device studied in this report can be used as altimeter or as altitude stabilizer (B.F. number PV 100-107, March 23, 1967). It includes essentially a 'surface barrier' semiconductor detector which counts alpha particles of a radioactive source. Two sources are used corresponding to two possible utilizations of the device. This report describes experiences made in laboratory which comprises electronic tests and a physic study. Systematic analysis of experimental errors is made comparatively with aneroid altimeters. An industrial device project is given. (author) [French] L'appareil etudie dans ce rapport peut etre utilise soit en altimetre, soit en stabilisateur d'altitude (B.F. numero PV 100-107, 23 mars 1967). Il comprend essentiellement un detecteur semiconducteur du type 'barriere de surface' qui compte les particules alpha d'une source radioactive. Deux sources sont utilisees correspondant aux deux utilisations possibles de l'appareil. Ce rapport decrit les experiences realisees en laboratoire, qui comprennent des tests electroniques et une etude physique. L'analyse systematique des diverses erreurs experimentales est faite, en comparaison avec les altimetres du type 'aneroide'. Un projet d'appareil est donne. (auteur)

  17. Determination and stabilization of the altitude of an aircraft in space using semi-conductor detectors; Determination et stabilisation de l'altitude d'un aeronef par detecteur a semiconducteur

    Energy Technology Data Exchange (ETDEWEB)

    Gilly, L [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1967-07-01

    The device studied in this report can be used as altimeter or as altitude stabilizer (B.F. number PV 100-107, March 23, 1967). It includes essentially a 'surface barrier' semiconductor detector which counts alpha particles of a radioactive source. Two sources are used corresponding to two possible utilizations of the device. This report describes experiences made in laboratory which comprises electronic tests and a physic study. Systematic analysis of experimental errors is made comparatively with aneroid altimeters. An industrial device project is given. (author) [French] L'appareil etudie dans ce rapport peut etre utilise soit en altimetre, soit en stabilisateur d'altitude (B.F. numero PV 100-107, 23 mars 1967). Il comprend essentiellement un detecteur semiconducteur du type 'barriere de surface' qui compte les particules alpha d'une source radioactive. Deux sources sont utilisees correspondant aux deux utilisations possibles de l'appareil. Ce rapport decrit les experiences realisees en laboratoire, qui comprennent des tests electroniques et une etude physique. L'analyse systematique des diverses erreurs experimentales est faite, en comparaison avec les altimetres du type 'aneroide'. Un projet d'appareil est donne. (auteur)

  18. Unmanned Aircraft Systems: The Road to Effective Integration

    National Research Council Canada - National Science Library

    Petrock, Christopher T; Huizenga, Thomas D

    2006-01-01

    ...) sharing airspace with manned assets. There have been at least two recent collisions between unmanned and rotary-wing aircraft at lower altitudes in Iraq, as well as numerous near misses with fixed-wing aircraft at higher altitudes...

  19. Red sprites and blue jets: Thunderstorm-excited optical emissions in the stratosphere, mesosphere, and ionosphere

    International Nuclear Information System (INIS)

    Sentman, D.D.; Wescott, E.M.

    1995-01-01

    Recent low light level monochrome television observations obtained from the ground and from the space shuttle, and low light level color and monochrome television images obtained from aboard jet aircraft, have shown that intense lightning in mesoscale thunderstorm systems may excite at least two distinct types of optical emissions that together span the space between the tops of some thunderstorms and the ionosphere. The first of these emissions, dubbed ''sprites,'' are luminous red structures that typically span the altitude range 60--90 km, often with faint bluish tendrils dangling below. A second, rarer, type of luminous emission are ''blue jets'' that appear to spurt upward out of the anvil top in narrow cones to altitudes of 40--50 km at speeds of ∼100 km/s. In this paper the principal observational characteristics of sprites and jets are presented, and several proposed production mechanisms are reviewed. copyright 1995 American Institute of Physics

  20. CARETS: A prototype regional environmental information system. Volume 6: Cost, accuracy and consistency comparisons of land use maps made from high-altitude aircraft photography and ERTS imagery

    Science.gov (United States)

    Alexander, R. H. (Principal Investigator); Fitzpatrick, K. A.

    1975-01-01

    The author has identified the following significant results. Level 2 land use maps produced at three scales (1:24,000, 1:100,000, and 1:250,000) from high altitude photography were compared with each other and with point data obtained in the field. The same procedures were employed to determine the accuracy of the Level 1 land use maps produced at 1:250,000 from high altitude photography and color composite ERTS imagery. Accuracy of the Level 2 maps was 84.9 percent at 1:24,000, 77.4 percent at 1:100,000 and 73.0 percent at 1:250,000. Accuracy of the Level 1 1:250,000 maps was 76.5 percent for aerial photographs and 69.5 percent for ERTS imagery. The cost of Level 2 land use mapping at 1:24,000 was found to be high ($11.93 per sq km). The cost of mapping at 1:100,000 ($1.75) was about two times as expensive as mapping at 1:250,000 ($.88), and the accuracy increased by only 4.4 percent.

  1. The Aircraft Industry

    National Research Council Canada - National Science Library

    Fitzgerald, Tim; Baiche, Noureddine; Brewer, Mike; Collins, Al; Knapp, Kathy; Kott, Marilyn; McGill, Duncan; Mensah, Dunstan; Neighbors, Mark; Reardon, Dee

    2005-01-01

    .... As the airline companies prepare to buy new Boeing and Airbus passenger jets, they remain under intense pressure to cut costs in order to remain profitable, forcing aircraft and engine manufacturers...

  2. Spatial Heterodyne Observations of Water (SHOW) vapour in the upper troposphere and lower stratosphere from a high altitude aircraft: Modelling and sensitivity analysis

    Science.gov (United States)

    Langille, J. A.; Letros, D.; Zawada, D.; Bourassa, A.; Degenstein, D.; Solheim, B.

    2018-04-01

    A spatial heterodyne spectrometer (SHS) has been developed to measure the vertical distribution of water vapour in the upper troposphere and the lower stratosphere with a high vertical resolution (∼500 m). The Spatial Heterodyne Observations of Water (SHOW) instrument combines an imaging system with a monolithic field-widened SHS to observe limb scattered sunlight in a vibrational band of water (1363 nm-1366 nm). The instrument has been optimized for observations from NASA's ER-2 aircraft as a proof-of-concept for a future low earth orbit satellite deployment. A robust model has been developed to simulate SHOW ER-2 limb measurements and retrievals. This paper presents the simulation of the SHOW ER-2 limb measurements along a hypothetical flight track and examines the sensitivity of the measurement and retrieval approach. Water vapour fields from an Environment and Climate Change Canada forecast model are used to represent realistic spatial variability along the flight path. High spectral resolution limb scattered radiances are simulated using the SASKTRAN radiative transfer model. It is shown that the SHOW instrument onboard the ER-2 is capable of resolving the water vapour variability in the UTLS from approximately 12 km - 18 km with ±1 ppm accuracy. Vertical resolutions between 500 m and 1 km are feasible. The along track sampling capability of the instrument is also discussed.

  3. An Operational Model for the Prediction of Jet Blast

    Science.gov (United States)

    2012-01-09

    This paper presents an operational model for the prediction of jet blast. The model was : developed based upon three modules including a jet exhaust model, jet centerline decay : model and aircraft motion model. The final analysis was compared with d...

  4. Aeroacoustics of compressible subsonic jets : Direct Numerical Simulation of a low Reynolds number subsonic jet and the associated sound field

    NARCIS (Netherlands)

    Moore, P.D.

    2009-01-01

    Jet noise is an extensively studied phenomenon since the deployment of the first civil jet aircraft more than 50 years ago. Jet noise makes up a considerable portion of the total noise of jet aircraft, and the expansion of the numbers of airplanes and airports has only been possible by keeping the

  5. Volcanic Ash -Aircraft Encounter Damages: in Volcanological Point of View

    Science.gov (United States)

    Aydar, Erkan; Aladaǧ, Çaǧdaş Hakan; Menteş, Turhan

    2017-04-01

    The jet era or age began at 1930 and 40's in aviation sector, with the production of first jet engine for the aircrafts. Since 1950's, the commercial aviation with regular flights were established. Civil aviation and air-transport drastically increased due to intensive demand, and declared at least 10 fold since 1970 by IATA report. Parallelly to technological and economical developpement, the commercial jets became more comfortable, secure and rapid, bringing the world smaller, the countries closer. On the other hand, according to Global Volcanism Program Catalogues of Smithsonian Institute, about 1,500 volcanoes have erupted in the Holocene, 550 of them have had historical eruptions and considered as active. Besides an average of 55-60 volcanoes erupt each year, and about 8-10 of these eruptions produce ash clouds that reach aircraft flight altitudes (Salinas and Watt, 2004). Volcanic ash can be expected to be in air routes at altitudes greater than 9 km (30,000 ft) for roughly 20 days per year worldwide (Miller &Casadeval, 2000). A precious compilation of incidents due to encounters of aircrafts with volcanic ash clouds covering the years between 1953 and 2009 was used in this work (Guffanti et al., 2010-USGS Report) with an additional information on Eyfjallajökull-2010 eruption. According to this compilation,129 incidents happened within the concerned time interval. The damages, in general, fall in second and third class of Severity index, indicating the damages are limited on airframe of the planes, or some abrasions in jet engine, windblast etc.. We focused on fourth class of severity index involving the damages on jet engine of aircraft (engine fail) due to ingestion of volcanic ash and investigate eruption style and caused damage relationships. During the eruptive sequences of Mts Saint Helen (USA), Galunggung (Indonesia, 2 incidents), Redoubt (USA), Pinatubo (Philipinnes), Unzen (Japan), Manam (Papua New Guinea), Soufriere Hills (Lesser Antilles), Chaiten

  6. A Thermodynamic, kinematic and microphysical analysis of a jet and gigantic jet-producing Florida thunderstorm

    Science.gov (United States)

    Lazarus, S. M.; Splitt, M. E.; Brownlee, James; Spiva, Nicholas; Liu, Ningyu

    2015-08-01

    This paper presents a meteorological analysis of a storm that produced two jets, four gigantic jets (GJ), and a starter, which were observed by two radars as well as the Kennedy Space Center 4-Dimensional Lightning Surveillance System on 3 August 2013 in Central Florida. The work is the first application of dual polarization data to a jet-producing storm and is the fifth case related to a tropical disturbance. The storm environment is consistent with the moist tropical paradigm that characterizes about three quarters of the surface and aircraft observed jet and GJ events. The most unstable (MU) convective available potential energy is not unusual for Florida summer convection and is below the climatological mean for these events. An unusual speed shear layer is located near the storm equilibrium level (EL) and the storm exhibits a tilted structure with CGs displaced upshear. The turbulence, as measured by the eddy dissipation rate, is extreme near the storm top during the event window, consistent with the GJ mixing hypothesis. The individual events are collocated with, and track along, the center axis of the divergent outflow at the EL and occur within the region of the coldest GOES IR temperatures—placing the events within the overshoot. The dual polarization data indicate a deep graupel column, extending above the mixed phase layer, to a 13 km altitude.

  7. Fuel-Conservation Guidance System for Powered-Lift Aircraft

    Science.gov (United States)

    Erzberger, Heinz; McLean, John D.

    1981-01-01

    A technique is described for the design of fuel-conservative guidance systems and is applied to a system that was flight tested on board NASA's sugmentor wing jet STOL research aircraft. An important operational feature of the system is its ability to rapidly synthesize fuel-efficient trajectories for a large set of initial aircraft positions, altitudes, and headings. This feature allows the aircraft to be flown efficiently under conditions of changing winds and air traffic control vectors. Rapid synthesis of fuel-efficient trajectories is accomplished in the airborne computer by fast-time trajectory integration using a simplified dynamic performance model of the aircraft. This technique also ensures optimum flap deployment and, for powered-lift STOL aircraft, optimum transition to low-speed flight. Also included in the design is accurate prediction of touchdown time for use in four-dimensional guidance applications. Flight test results have demonstrated that the automatically synthesized trajectories produce significant fuel savings relative to manually flown conventional approaches.

  8. Alternate Fuels for Use in Commercial Aircraft

    Science.gov (United States)

    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.

  9. Inerting Aircraft Fuel Systems Using Exhaust Gases

    Science.gov (United States)

    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.

  10. Aerosol vertical distribution, new particle formation, and jet aircraft particle emissions in the free troposhere and tropopause region; Vertikalverteilung und Neubildungsprozesse des Aerosols und partikelfoermige Flugzeugemissionen in der freien Troposphaere und Tropopausenregion

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, F P

    2000-07-01

    A contribution to the understanding of natural and anthropogenously induced particle formation as well as aerosol physical transformation processes within the free troposphere (FT) is introduced. Documentation and interpretation of empirical data relevant with respect to possible climatologic impact of anthropogenous aerosol emissions into the atmosphere is presented. The first section describes new technique for high spatial resolution measurements of ultrafine aerosol particles by condensation nucleus counters (CNCs), a necessary prerequisite for the observation of natural particle formation and jet aircraft emissions. The second section illustrates vertical distribution and variability ranges of the aerosol in the FT and the tropopause region (TP). Typical microphysical states of the atmospheric aerosol within the Northern Hemisphere are documented by means of systematic measurements during more than 60 flight missions. Simple mathematical parameterizations of the aerosol vertical distribution and aerosol size distributions are developed. Important aerosol sources within the FT are localized and possible aerosol formation processes are discussed. The third section is focussed on jet-engine particle emissions within the FT and TP. A unique inflight experiment for detection of extremely high concentrations (>10{sup 6} cm{sup -3}) of extremely small (donw to <3 nm) aerosols inside the exhaust plumes of several jet aircraft is described. Particle emission indices and emission-controlling parameters are deduced. Most important topic is the impact of fuel sulfur content of kerosine on number, size and chemical composition of jet particle emissions. Generalized results are parameterized in form of lognormal aerosol particle size distributions. (orig.) [German] Ein Beitrag zum Verstaendnis natuerlicher und anthropogen induzierter Aerosolneubildung sowie physikalischer Aerosolumwandlung in der freien Troposphaere wird vorgestellt. Empirisch gewonnenes Datenmaterial wird

  11. COMMERCIAL SUPERSONIC TRANSPORT PROGRAM. PHASE II-C REPORT. HIGH STRENGTH STEEL EVALUATION FOR SUPERSONIC AIRCRAFT.

    Science.gov (United States)

    JET TRANSPORT AIRCRAFT, *AIRFRAMES, SUPERSONIC AIRCRAFT, STEEL , STRUCTURAL PROPERTIES, FRACTURE(MECHANICS), FATIGUE(MECHANICS), STRESS CORROSION...MICROPHOTOGRAPHY, HIGH TEMPERATURE, NICKEL ALLOYS, COBALT ALLOYS, CARBON, BAINITE , COMMERCIAL AIRCRAFT.

  12. In-flight imaging of transverse gas jets injected into transonic and supersonic crossflows: Design and development. M.S. Thesis, Mar. 1993

    Science.gov (United States)

    Wang, Kon-Sheng Charles

    1994-01-01

    The design and development of an airborne flight-test experiment to study nonreacting gas jets injected transversely into transonic and supersonic crossflows is presented. Free-stream/crossflow Mach numbers range from 0.8 to 2.0. Planar laser-induced fluorescence (PLIF) of an iodine-seeded nitrogen jet is used to visualize the jet flow. Time-dependent images are obtained with a high-speed intensified video camera synchronized to the laser pulse rate. The entire experimental assembly is configured compactly inside a unique flight-test-fixture (FTF) mounted under the fuselage of the F-104G research aircraft, which serves as a 'flying wind tunnel' at NASA Dryden Flight Research Center. The aircraft is flown at predetermined speeds and altitudes to permit a perfectly expanded (or slightly underexpanded) gas jet to form just outside the FTF at each free-stream Mach number. Recorded gas jet images are then digitized to allow analysis of jet trajectory, spreading, and mixing characteristics. Comparisons will be made with analytical and numerical predictions. This study shows the viability of applying highly sophisticated groundbased flow diagnostic techniques to flight-test vehicle platforms that can achieve a wide range of thermo/fluid dynamic conditions. Realistic flow environments, high enthalpies, unconstrained flowfields, and moderate operating costs are also realized, in contrast to traditional wind-tunnel testing.

  13. Active Control of Supersonic Impinging Jets Using Supersonic Microjets

    National Research Council Canada - National Science Library

    Alvi, Farrukh

    2005-01-01

    .... Supersonic impinging jets occur in many applications including in STOVL aircraft where they lead to a highly oscillatory flow with very high unsteady loads on the nearby aircraft structures and the landing surfaces...

  14. Analysis of the engine fragment threat and the crush environment for small packages carried on U.S. commercial jet aircraft

    International Nuclear Information System (INIS)

    Hartman, W.F.; McClure, J.D.; von Riesemann, W.A.

    1978-01-01

    The results of two separate analyses are reported. The engine fragment analysis determined the probability of a small package being in the path of a fragment from a failure in a gas turbine engine. The calculated values show that, depending on aircraft type, the incidence rate varies by approximately an order of magnitude from a high of about once per 5 million flights to a low of nearly once every 40 million package flights for a flight of five hours' duration. The analysis of the crush environment consisted of an examination of two principal crush modes, i.e., vertical and longitudinal crush. The vertical crush mode was examined by formulating a structural model of the cargo deck beams of the aircraft. The longitudinal crush mode was studied by using dynamic models of the aircraft cargo and the radioactive material package (RAM). The results of the analysis of these crush modes provided the basis for the formulation of a 310 kN/(70,000 lb) crush test to simulate vertical crush. The longitudinal crush analysis indicated that it was possible, under infrequently occurring conditions, to produce extremely large crush forces and hence it was recommended that RAM packages be located in the aft end of aircraft cargo compartments to minimize the effects of longitudinal crush

  15. Impingement heat/mass transfer to hybrid synthetic jets and other reversible pulsating jets

    Czech Academy of Sciences Publication Activity Database

    Trávníček, Zdeněk; Vít, T.

    2015-01-01

    Roč. 85, June (2015), s. 473-487 ISSN 0017-9310 R&D Projects: GA ČR GA14-08888S Institutional support: RVO:61388998 Keywords : impinging jet * reversible pulsating jet * synthetic jet Subject RIV: JU - Aeronautics, Aerodynamics, Aircrafts Impact factor: 2.857, year: 2015 http://www.sciencedirect.com/science/article/pii/S001793101500143X

  16. Aircraft Vortex Wake Decay Near the Ground

    Science.gov (United States)

    1977-05-01

    A multi-faceted experimental and analytical research program was carried out to explore the details of aircraft wake vortex breakdown under conditions representative of those which prevail at low altitudes in the vicinity of airports. Three separate ...

  17. Combat aircraft noise

    Science.gov (United States)

    Sgarbozza, M.; Depitre, A.

    1992-04-01

    A discussion of the characteristics and the noise levels of combat aircraft and of a transport aircraft in taking off and landing are presented. Some methods of noise reduction are discussed, including the following: operational anti-noise procedures; and concepts of future engines (silent post-combustion and variable cycle). Some measurement results concerning the noise generated in flight at great speeds and low altitude will also be examined. Finally, the protection of the environment of French air bases against noise will be described and the possibilities of regulation examined.

  18. Athletes at High Altitude.

    Science.gov (United States)

    Khodaee, Morteza; Grothe, Heather L; Seyfert, Jonathan H; VanBaak, Karin

    2016-01-01

    Athletes at different skill levels perform strenuous physical activity at high altitude for a variety of reasons. Multiple team and endurance events are held at high altitude and may place athletes at increased risk for developing acute high altitude illness (AHAI). Training at high altitude has been a routine part of preparation for some of the high level athletes for a long time. There is a general belief that altitude training improves athletic performance for competitive and recreational athletes. A review of relevant publications between 1980 and 2015 was completed using PubMed and Google Scholar. Clinical review. Level 3. AHAI is a relatively uncommon and potentially serious condition among travelers to altitudes above 2500 m. The broad term AHAI includes several syndromes such as acute mountain sickness (AMS), high altitude pulmonary edema (HAPE), and high altitude cerebral edema (HACE). Athletes may be at higher risk for developing AHAI due to faster ascent and more vigorous exertion compared with nonathletes. Evidence regarding the effects of altitude training on athletic performance is weak. The natural live high, train low altitude training strategy may provide the best protocol for enhancing endurance performance in elite and subelite athletes. High altitude sports are generally safe for recreational athletes, but they should be aware of their individual risks. Individualized and appropriate acclimatization is an essential component of injury and illness prevention.

  19. DLR HABLEG- High Altitude Balloon Launched Experimental Glider

    Science.gov (United States)

    Wlach, S.; Schwarzbauch, M.; Laiacker, M.

    2015-09-01

    The group Flying Robots at the DLR Institute of Robotics and Mechatronics in Oberpfaffenhofen conducts research on solar powered high altitude aircrafts. Due to the high altitude and the almost infinite mission duration, these platforms are also denoted as High Altitude Pseudo-Satellites (HAPS). This paper highlights some aspects of the design, building, integration and testing of a flying experimental platform for high altitudes. This unmanned aircraft, with a wingspan of 3 m and a mass of less than 10 kg, is meant to be launched as a glider from a high altitude balloon in 20 km altitude and shall investigate technologies for future large HAPS platforms. The aerodynamic requirements for high altitude flight included the development of a launch method allowing for a safe transition to horizontal flight from free-fall with low control authority. Due to the harsh environmental conditions in the stratosphere, the integration of electronic components in the airframe is a major effort. For regulatory reasons a reliable and situation dependent flight termination system had to be implemented. In May 2015 a flight campaign was conducted. The mission was a full success demonstrating that stratospheric research flights are feasible with rather small aircrafts.

  20. 75 FR 5203 - Certification of Aircraft and Airmen for the Operation of Light-Sport Aircraft; Modifications to...

    Science.gov (United States)

    2010-02-01

    ... training courses approved under part 141. 22. Revise the minimum safe-altitude requirements for powered... that glider pilots are permitted to fly at that altitude. One commenter suggested that training in the... pilots receive training in reduced aircraft performance at high-density altitudes and in the effect of...

  1. Study of short-haul aircraft operating economics. Phase 2: an analysis of the impact of jet modernization on local service airline operating costs. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Andrastek, D.A.

    1976-05-01

    The objectives of this phase of the study were (1) to assess the 10 year operating cost trends of the local service airlines operating in the 1965 through 1974 period, (2) to glean from these trends the technological and operational parameters which were impacted most significantly by the transition to newer pure jet, short haul transports, and effected by changing fuel prices and cost of living indices, and (3) to develop, construct, and evaluate an operating cost forecasting model which would incorporate those factors which best predicted airline total operating cost behavior over that 10-year period.

  2. Annular Impinging Jet Controlled by Radial Synthetic Jets

    Czech Academy of Sciences Publication Activity Database

    Trávníček, Zdeněk; Tesař, Václav; Broučková, Zuzana; Peszyński, K.

    2014-01-01

    Roč. 35, 16-17 (2014), s. 1450-1461 ISSN 0145-7632 R&D Projects: GA ČR GA14-08888S; GA AV ČR(CZ) IAA200760801 Institutional support: RVO:61388998 Keywords : impinging jet * hybrid synthetic jet * flow control Subject RIV: JU - Aeronautics, Aerodynamics, Aircrafts Impact factor: 0.814, year: 2014 http://dx.doi.org/10.1080/01457632.2014.889467

  3. The radiation protection problems of high altitude and space flight

    International Nuclear Information System (INIS)

    Fry, R.J.M.

    1993-01-01

    This paper considers the radiation environment in aircraft at high altitudes and spacecraft in low earth orbit and in deep space and the factors that influence the dose equivalents. Altitude, latitude and solar cycle are the major influences for flights below the radiation belts. In deep space, solar cycle and the occurrence of solar particle events are the factors of influence. The major radiation effects of concern are cancer and infertility in males. In high altitude aircraft the radiation consists mainly of protons and neutrons, with neutrons contributing about half the equivalent dose. The average dose rate at altitudes of transcontinental flights that approach the polar regions are greater by a factor of about 2.5 than on routes at low latitudes. Current estimates of does to air crews suggest they are well within the ICRP (1990) recommended dose limits for radiation workers

  4. Jet observables without jet algorithms

    Energy Technology Data Exchange (ETDEWEB)

    Bertolini, Daniele; Chan, Tucker; Thaler, Jesse [Center for Theoretical Physics, Massachusetts Institute of Technology,Cambridge, MA 02139 (United States)

    2014-04-02

    We introduce a new class of event shapes to characterize the jet-like structure of an event. Like traditional event shapes, our observables are infrared/collinear safe and involve a sum over all hadrons in an event, but like a jet clustering algorithm, they incorporate a jet radius parameter and a transverse momentum cut. Three of the ubiquitous jet-based observables — jet multiplicity, summed scalar transverse momentum, and missing transverse momentum — have event shape counterparts that are closely correlated with their jet-based cousins. Due to their “local” computational structure, these jet-like event shapes could potentially be used for trigger-level event selection at the LHC. Intriguingly, the jet multiplicity event shape typically takes on non-integer values, highlighting the inherent ambiguity in defining jets. By inverting jet multiplicity, we show how to characterize the transverse momentum of the n-th hardest jet without actually finding the constituents of that jet. Since many physics applications do require knowledge about the jet constituents, we also build a hybrid event shape that incorporates (local) jet clustering information. As a straightforward application of our general technique, we derive an event-shape version of jet trimming, allowing event-wide jet grooming without explicit jet identification. Finally, we briefly mention possible applications of our method for jet substructure studies.

  5. Classical altitude training.

    Science.gov (United States)

    Friedmann-Bette, B

    2008-08-01

    For more than 40 years, the effects of classical altitude training on sea-level performance have been the subject of many scientific investigations in individual endurance sports. To our knowledge, no studies have been performed in team sports like football. Two well-controlled studies showed that living and training at an altitude of >or=1800-2700 m for 3-4 weeks is superior to equivalent training at sea level in well-trained athletes. Most of the controlled studies with elite athletes did not reveal such an effect. However, the results of some uncontrolled studies indicate that sea-level performance might be enhanced after altitude training also in elite athletes. Whether hypoxia provides an additional stimulus for muscular adaptation, when training is performed with equal intensity compared with sea-level training is not known. There is some evidence for an augmentation of total hemoglobin mass after classical altitude training with duration >or=3 weeks at an altitude >or=2000 m due to altitude acclimatization. Considerable individual variation is observed in the erythropoietic response to hypoxia and in the hypoxia-induced reduction of aerobic performance capacity during training at altitude, both of which are thought to contribute to inter-individual variation in the improvement of sea-level performance after altitude training.

  6. The microburst - Hazard to aircraft

    Science.gov (United States)

    Mccarthy, J.; Serafin, R.

    1984-01-01

    In encounters with microbursts, low altitude aircraft first encounter a strong headwind which increases their wing lift and altitude; this phenomenon is followed in short succession by a decreasing headwind component, a downdraft, and finally a strong tailwind that catastrophically reduces wing lift and precipitates a crash dive. It is noted that the potentially lethal low altitude wind shear of a microburst may lie in apparently harmless, rain-free air beneath a cloud base. Occasionally, such tell-tale signs as localized blowing of ground dust may be sighted in time. Microbursts may, however, occur in the heavy rain of a thunderstorm, where they will be totally obscured from view. Wind shear may be detected by an array of six anemometers and vanes situated in the vicinity of an airport, and by Doppler radar equipment at the airport or aboard aircraft.

  7. HIGH-ALTITUDE ILLNESS

    Directory of Open Access Journals (Sweden)

    Dwitya Elvira

    2015-05-01

    Full Text Available AbstrakHigh-altitude illness (HAI merupakan sekumpulan gejala paru dan otak yang terjadi pada orang yang baru pertama kali mendaki ke ketinggian. HAI terdiri dari acute mountain sickness (AMS, high-altitude cerebral edema (HACE dan high-altitude pulmonary edema (HAPE. Tujuan tinjauan pustaka ini adalah agar dokter dan wisatawan memahami risiko, tanda, gejala, dan pengobatan high-altitude illness. Perhatian banyak diberikan terhadap penyakit ini seiring dengan meningkatnya popularitas olahraga ekstrim (mendaki gunung tinggi, ski dan snowboarding dan adanya kemudahan serta ketersediaan perjalanan sehingga jutaan orang dapat terpapar bahaya HAI. Di Pherice, Nepal (ketinggian 4343 m, 43% pendaki mengalami gejala AMS. Pada studi yang dilakukan pada tempat wisata di resort ski Colorado, Honigman menggambarkan kejadian AMS 22% pada ketinggian 1850 m sampai 2750 m, sementara Dean menunjukkan 42% memiliki gejala pada ketinggian 3000 m. Aklimatisasi merupakan salah satu tindakan pencegahan yang dapat dilakukan sebelum pendakian, selain beberapa pengobatan seperti asetazolamid, dexamethasone, phosopodiestrase inhibitor, dan ginko biloba.Kata kunci: high-altitude illness, acute mountain sickness, edema cerebral, pulmonary edema AbstractHigh-altitude illness (HAI is symptoms of lung and brain that occurs in people who first climb to altitude. HAI includes acute mountain sickness (AMS, high-altitude cerebral edema (HACE and high altitude pulmonary edema (HAPE. The objective of this review was to understand the risks, signs, symptoms, and treatment of high-altitude illness. The attention was given to this disease due to the rising popularity of extreme sports (high mountain climbing, skiing and snowboarding and the ease and availability of the current travelling, almost each year, millions of people could be exposed to the danger of HAI. In Pherice, Nepal (altitude 4343 m, 43% of climbers have symptoms of AMS. Furthermore, in a study conducted at sites in

  8. Systems Design and Experimental Evaluation of a High-Altitude Relight Test Facility

    Science.gov (United States)

    Paxton, Brendan

    Novel advances in gas turbine engine combustor technology, led by endeavors into fuel efficiency and demanding environmental regulations, have been fraught with performance and safety concerns. While the majority of low emissions gas turbine engine combustor technology has been necessary for power generation applications, the push for ultra-low NOx combustion in aircraft jet engines has been ever present. Recent state-of-the-art combustor designs notably tackle historic emissions challenges by operating at fuel-lean conditions, which are characterized by an increase in the amount of air flow sent to the primary combustion zone. While beneficial in reducing NOx emissions, the fuel-lean mechanisms that characterize these combustor designs rely heavily upon high-energy and high-velocity air flows to sufficiently mix and atomize fuel droplets, ultimately leading to flame stability concerns during low-power operation. When operating at high-altitude conditions, these issues are further exacerbated by the presence of low ambient air pressures and temperatures, which can lead to engine flame-out situations and hamper engine relight attempts. To aid academic and industrial research ventures into improving the high-altitude lean blow-out and relight performance of modern gas turbine engine combustor technologies, the High-Altitude Relight Test Facility (HARTF) was designed and constructed at the University of Cincinnati (UC) Combustion and Fire Research Laboratory (CFRL). Following its construction, an experimental evaluation of its abilities to facilitate optically-accessible ignition, combustion, and spray testing for gas turbine engine combustor hardware at simulated high-altitude conditions was performed. In its evaluation, performance limit references were established through testing of the HARTF vacuum and cryogenic air-chilling capabilities. These tests were conducted with regard to end-user control---the creation and the maintenance of a realistic high-altitude

  9. PIV Measurements of Chevrons on F400-Series Tactical Aircraft Nozzle Model

    Science.gov (United States)

    Bridges, James; Wernet, Mark P.; Frate, Franco C.

    2011-01-01

    Reducing noise of tactical jet aircraft has taken on fresh urgency as core engine technologies allow higher specific-thrust engines and as society become more concerned for the health of its military workforce. Noise reduction on this application has lagged the commercial field as incentives for quieting military aircraft have not been as strong as in their civilian counterparts. And noise reduction strategies employed on civilian engines may not be directly applicable due to the differences in exhaust system architecture and mission. For instance, the noise reduction technology of chevrons, examined in this study, will need to be modified to take into account the special features of tactical aircraft nozzles. In practice, these nozzles have divergent slats that are tied to throttle position, and at take off the jet flow is highly overexpanded as the nozzle is optimized for cruise altitude rather than sea level. In simple oil flow visualization experiments conducted at the onset of the current test program flow barely stays attached at end of nozzle at takeoff conditions. This adds a new twist to the design of chevrons. Upon reaching the nozzle exit the flow shrinks inward radially, meaning that for a chevron to penetrate the flow it must extend much farther away from the baseline nozzle streamline. Another wrinkle is that with a variable divergence angle on the nozzle, the effective penetration will differ with throttle position and altitude. The final note of realism introduced in these experiments was to simulate the manner in which bypass flow is bled into the nozzle wall in real engines to cool the nozzle, which might cause very fat boundary layer at exit. These factors, along with several other issues specific to the application of chevrons to convergent-divergent nozzles have been explored with particle image velocimetry measurements and are presented in this paper.

  10. Electric jets following the occurrence of sprites

    Science.gov (United States)

    Lee, L.; Chou, J.; Huang, S.; Chang, S.; Wu, Y.; Lee, Y.; Kuo, C.; Chen, A. B.; Su, H.; Hsu, R.; Frey, H. U.; Mende, S. B.; Takahashi, Y.; Lee, L.

    2010-12-01

    Sprites are discharges occurring at the altitudes ~40 to 90 km, which are usually associated with positive cloud-to-ground lightning (+CGs). Electric jets, which include blue jets (BJs) with the terminal altitude of ~40km and gigantic jets (GJs) emanating to the lower ionosphere, are upward discharges from the cloud tops toward the upper atmosphere. From previous ground observations, it has been reported that the secondary discharges (“palm-tree” [Heavner, 2000] or “sprite-initiated secondary TLEs” [Marshall and Inan, 2007]) following sprites occurred in altitudes between the cloud top and the bottom of the sprite. From July 2004 to June 2010, ISUAL has recorded dozens of events which resemble the secondary TLEs. From image and photometric data recorded by ISUAL, all these secondary TLEs have the characteristics of jets, so we call these events “secondary jets”. These secondary jets are categorized into two groups according to their emanating horizontal positions in relative to the sprites. Group-I secondary jets occurred in the cloud top region which is directly below the sprites. The terminal altitude is ~ 40-50km for most of group-I secondary jets. Several group-I secondary jets appear to originate from the cloud top region below the symmetric center of the clustering sprites and then propagate toward the lower ionosphere. While the group-II secondary jets originate from region outside the shielding area of the clustering sprites. In this paper, the image and the photometric characteristics of the secondary jets will be presented and the possible generating mechanisms will be discussed.

  11. Multi-objective optimization of aircraft design for emission and cost reductions

    Directory of Open Access Journals (Sweden)

    Wang Yu

    2014-02-01

    Full Text Available Pollutant gases emitted from the civil jet are doing more and more harm to the environment with the rapid development of the global commercial aviation transport. Low environmental impact has become a new requirement for aircraft design. In this paper, estimation method for emission in aircraft conceptual design stage is improved based on the International Civil Aviation Organization (ICAO aircraft engine emissions databank and the polynomial curve fitting methods. The greenhouse gas emission (CO2 equivalent per seat per kilometer is proposed to measure the emissions. An approximate sensitive analysis and a multi-objective optimization of aircraft design for tradeoff between greenhouse effect and direct operating cost (DOC are performed with five geometry variables of wing configuration and two flight operational parameters. The results indicate that reducing the cruise altitude and Mach number may result in a decrease of the greenhouse effect but an increase of DOC. And the two flight operational parameters have more effects on the emissions than the wing configuration. The Pareto-optimal front shows that a decrease of 29.8% in DOC is attained at the expense of an increase of 10.8% in greenhouse gases.

  12. High altitude illness

    Science.gov (United States)

    Hartman-Ksycińska, Anna; Kluz-Zawadzka, Jolanta; Lewandowski, Bogumił

    High-altitude illness is a result of prolonged high-altitude exposure of unacclimatized individuals. The illness is seen in the form of acute mountain sickness (AMS) which if not treated leads to potentially life-threatening high altitude pulmonary oedema and high-altitude cerebral oedema. Medical problems are caused by hypobaric hypoxia stimulating hypoxia-inducible factor (HIF) release. As a result, the central nervous system, circulation and respiratory system function impairment occurs. The most important factor in AMS treatment is acclimatization, withdrawing further ascent and rest or beginning to descent; oxygen supplementation, and pharmacological intervention, and, if available, a portable hyperbaric chamber. Because of the popularity of high-mountain sports and tourism better education of the population at risk is essential.

  13. Endurance training at altitude.

    Science.gov (United States)

    Saunders, Philo U; Pyne, David B; Gore, Christopher J

    2009-01-01

    Since the 1968 Olympic Games when the effects of altitude on endurance performance became evident, moderate altitude training ( approximately 2000 to 3000 m) has become popular to improve competition performance both at altitude and sea level. When endurance athletes are exposed acutely to moderate altitude, a number of physiological responses occur that can comprise performance at altitude; these include increased ventilation, increased heart rate, decreased stroke volume, reduced plasma volume, and lower maximal aerobic power ((.)Vo(2max)) by approximately 15% to 20%. Over a period of several weeks, one primary acclimatization response is an increase in the volume of red blood cells and consequently of (.)Vo(2max). Altitudes > approximately 2000 m for >3 weeks and adequate iron stores are required to elicit these responses. However, the primacy of more red blood cells for superior sea-level performance is not clear-cut since the best endurance athletes in the world, from Ethiopia (approximately 2000 to 3000 m), have only marginally elevated hemoglobin concentrations. The substantial reduction in (.)Vo(2max) of athletes at moderate altitude implies that their training should include adequate short-duration (approximately 1 to 2 min), high-intensity efforts with long recoveries to avoid a reduction in race-specific fitness. At the elite level, athlete performance is not dependent solely on (.)Vo(2max), and the "smallest worthwhile change" in performance for improving race results is as little as 0.5%. Consequently, contemporary statistical approaches that utilize the concept of the smallest worthwhile change are likely to be more appropriate than conventional statistical methods when attempting to understand the potential benefits and mechanisms of altitude training.

  14. Altitude and endurance training.

    Science.gov (United States)

    Rusko, Heikki K; Tikkanen, Heikki O; Peltonen, Juha E

    2004-10-01

    The benefits of living and training at altitude (HiHi) for an improved altitude performance of athletes are clear, but controlled studies for an improved sea-level performance are controversial. The reasons for not having a positive effect of HiHi include: (1) the acclimatization effect may have been insufficient for elite athletes to stimulate an increase in red cell mass/haemoglobin mass because of too low an altitude (altitude training period (training effect at altitude may have been compromised due to insufficient training stimuli for enhancing the function of the neuromuscular and cardiovascular systems; and (3) enhanced stress with possible overtraining symptoms and an increased frequency of infections. Moreover, the effects of hypoxia in the brain may influence both training intensity and physiological responses during training at altitude. Thus, interrupting hypoxic exposure by training in normoxia may be a key factor in avoiding or minimizing the noxious effects that are known to occur in chronic hypoxia. When comparing HiHi and HiLo (living high and training low), it is obvious that both can induce a positive acclimatization effect and increase the oxygen transport capacity of blood, at least in 'responders', if certain prerequisites are met. The minimum dose to attain a haematological acclimatization effect is > 12 h a day for at least 3 weeks at an altitude or simulated altitude of 2100-2500 m. Exposure to hypoxia appears to have some positive transfer effects on subsequent training in normoxia during and after HiLo. The increased oxygen transport capacity of blood allows training at higher intensity during and after HiLo in subsequent normoxia, thereby increasing the potential to improve some neuromuscular and cardiovascular determinants of endurance performance. The effects of hypoxic training and intermittent short-term severe hypoxia at rest are not yet clear and they require further study.

  15. Jet fragmentation

    International Nuclear Information System (INIS)

    Saxon, D.H.

    1985-10-01

    The paper reviews studies on jet fragmentation. The subject is discussed under the topic headings: fragmentation models, charged particle multiplicity, bose-einstein correlations, identified hadrons in jets, heavy quark fragmentation, baryon production, gluon and quark jets compared, the string effect, and two successful models. (U.K.)

  16. Multi-Fuel Rotary Engine for General Aviation Aircraft

    Science.gov (United States)

    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.

  17. Blue jets and gigantic jets: transient luminous events between thunderstorm tops and the lower ionosphere

    International Nuclear Information System (INIS)

    Pasko, V P

    2008-01-01

    An overview of general phenomenology and proposed physical mechanisms of large scale electrical discharges termed 'blue jets' and 'gigantic jets' observed at high altitude in the Earth's atmosphere above thunderstorms is presented. The primary emphasis is placed on summarizing available experimental data on the observed morphological features of upward jet discharges and on the discussion of recently advanced theories describing electrodynamic conditions, which facilitate escape of conventional lightning leaders from thundercloud tops and their upward propagation toward the ionosphere. It is argued that the filamentary plasma structures observed in blue jet and gigantic jet discharges are directly linked to the processes in streamer zones of lightning leaders, scaled by a significant reduction of air pressure at high altitudes.

  18. High Altitude and Heart

    Directory of Open Access Journals (Sweden)

    Murat Yalcin

    2011-04-01

    Full Text Available Nowadays, situations associated with high altitude such as mountaineering, aviation increasingly draw the attention of people. Gas pressure decreases and hypoxia is encountered when climbing higher. Physiological and pathological responses of human body to different heights are different. Therefore, physiological and pathological changes that may occur together with height and to know the clinical outcomes of these are important . Acute mountain sickness caused by high altitude and high altitude cerebral edema are preventable diseases with appropriate precautions. Atmospheric oxygen decreasing with height, initiates many adaptive mechanisms. These adaptation mechanisms and acclimatization vary widely among individuals because of reasons such as environmental factors, exercise and cold. High altitude causes different changes in the cardiovascular system with various mechanisms. Although normal individuals easily adapt to these changes, this situation can lead to undesirable results in people with heart disease. For this reason, it should be known the effective evaluation of the people with known heart disease before traveling to high altitude and the complications due to the changes with height and the recommendations can be made to these patients. [TAF Prev Med Bull 2011; 10(2.000: 211-222

  19. Characteristic study of DC electric Arc plasma igniter jet

    International Nuclear Information System (INIS)

    Lan Yudan; He Liming; Du Hongliang; Wang Feng; Chen Xin

    2012-01-01

    The spectrometer was adopted to measure the emission spectrum of Ar plasma jet at the igniter exit. Boltzmann curve slope method was applied to calculate the jet electron temperature. Ionization equilibrium equation was used to calculate jet temperature and measure the laws that jet length, jet velocity, electron temperature and jet temperature of igniter exit change with arc current and inlet Ar flow rate. Whether the electron temperature could be used to replace jet temperature in aircraft plasma arc jet was also discussed. The experiment results show that arc current reduces with the rising of inlet Ar flow rate; exit jet length and velocity increase with the rising of arc current, and increase at first and then reduce with the rising of inlet Ar flow rate; exit electron temperature, electron density and jet temperature increase with the rising of arc current and reduce with the rising of inlet Ar flow rate. (authors)

  20. High altitude organic gold

    DEFF Research Database (Denmark)

    Pouliot, Mariève; Pyakurel, Dipesh; Smith-Hall, Carsten

    2018-01-01

    Ethnopharmacological relevance Ophiocordyceps sinensis (Berk.) G.H.Sung, J.M.Sung, Hywel-Jones & Spatafora, a high altitude Himalayan fungus-caterpillar product found in alpine meadows in China, Bhutan, Nepal, and India, has been used in the Traditional Chinese Medicine system for over 2000 years...

  1. Pathfinder-Plus aircraft in flight

    Science.gov (United States)

    1998-01-01

    The Pathfinder-Plus solar-powered aircraft is shown taking off from a runway, then flying at low altitude over the ocean. The vehicle, which looks like a flying ruler, operates at low airspeed. Among the missions proposed for a solar-powered aircraft are communications relay, atmospheric studies, pipeline monitoring and gas leak detection, environmental monitoring using thermal and radar images, and disaster relief and monitoring.

  2. International Pacific Air and Space Technology Conference and Aircraft Symposium, 29th, Gifu, Japan, Oct. 7-11, 1991, Proceedings

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    Various papers on air and space technology are presented. Individual topics addressed include: media selection analysis: implications for training design, high-speed challenge for rotary wing aircraft, high-speed VSTOL answer to congestion, next generation in computational aerodynamics, acrobatic airship 'Acrostat', ducted fan VTOL for working platform, Arianespace launch of Lightsats, small particle acceleration by minirailgun, free-wake analyses of a hovering rotor using panel method, update of the X-29 high-angle-of-attack program, economic approach to accurate wing design, flow field around thick delta wing with rounded leading edge, aerostructural integrated design of forward-swept wing, static characteristics of a two-phase fluid drop system, simplfied-model approach to group combustion of fuel spray, avionics flight systems for the 21st century. Also discussed are: Aircraft Command in Emergency Situations, spectrogram diagnosis of aircraft disasters, shock interaction induced by two hemisphere-cylinders, impact response of composite UHB propeller blades, high-altitude lighter-than-air powered platform, integrated wiring system, auxiliary power units for current and future aircraft, Space Shuttle Orbiter Auxiliary Power Unit status, numerical analysis of RCS jet in hypersonic flights, energy requirements for the space frontier, electrical system options for space exploration, aerospace plane hydrogen scramjet boosting, manual control of vehicles with time-varying dynamics, design of strongly stabilizing controller, development of the Liquid Apogee Propulsion System for ETS-VI

  3. International Pacific Air and Space Technology Conference and Aircraft Symposium, 29th, Gifu, Japan, Oct. 7-11, 1991, Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    1991-01-01

    Various papers on air and space technology are presented. Individual topics addressed include: media selection analysis: implications for training design, high-speed challenge for rotary wing aircraft, high-speed VSTOL answer to congestion, next generation in computational aerodynamics, acrobatic airship 'Acrostat', ducted fan VTOL for working platform, Arianespace launch of Lightsats, small particle acceleration by minirailgun, free-wake analyses of a hovering rotor using panel method, update of the X-29 high-angle-of-attack program, economic approach to accurate wing design, flow field around thick delta wing with rounded leading edge, aerostructural integrated design of forward-swept wing, static characteristics of a two-phase fluid drop system, simplfied-model approach to group combustion of fuel spray, avionics flight systems for the 21st century. Also discussed are: Aircraft Command in Emergency Situations, spectrogram diagnosis of aircraft disasters, shock interaction induced by two hemisphere-cylinders, impact response of composite UHB propeller blades, high-altitude lighter-than-air powered platform, integrated wiring system, auxiliary power units for current and future aircraft, Space Shuttle Orbiter Auxiliary Power Unit status, numerical analysis of RCS jet in hypersonic flights, energy requirements for the space frontier, electrical system options for space exploration, aerospace plane hydrogen scramjet boosting, manual control of vehicles with time-varying dynamics, design of strongly stabilizing controller, development of the Liquid Apogee Propulsion System for ETS-VI.

  4. Characteristics and generation of secondary jets and secondary gigantic jets

    Science.gov (United States)

    Lee, Li-Jou; Huang, Sung-Ming; Chou, Jung-Kung; Kuo, Cheng-Ling; Chen, Alfred B.; Su, Han-Tzong; Hsu, Rue-Rou; Frey, Harald U.; Takahashi, Yukihiro; Lee, Lou-Chuang

    2012-06-01

    Secondary transient luminous events (TLEs) recorded by the ISUAL-FORMOSAT2 mission can either be secondary jets or secondary gigantic jets (GJs), depending on their terminal altitudes. The secondary jets emerge from the cloud top beneath the preceding sprites and extend upward to the base of the sprites at ˜50 km. The secondary jets likely are negative electric discharges with vertically straight luminous columns, morphologically resembling the trailing jet of the type-I GJs. The number of luminous columns in a secondary jet seems to be affected by the size of the effective capacitor plate formed near the base of the preceding sprites and the charge distribution left behind by the sprite-inducing positive cloud-to-ground discharges. The secondary GJs originate from the cloud top under the shielding area of the preceding sprites, and develop upward to reach the lower ionosphere at ˜90 km. The observed morphology of the secondary GJs can either be the curvy shifted secondary GJs extending outside the region occupied by the preceding sprites or the straight pop-through secondary GJs developing through the center of the preceding circular sprites. A key factor in determining the terminal height of the secondary TLEs appears to be the local ionosphere boundary height that established by the preceding sprites. The abundance and the distribution of the negative charge in the thundercloud following the sprite-inducing positive cloud-to-ground discharges may play important role in the generation of the secondary TLEs.

  5. Modeling of aircraft exhaust emissions and infrared spectra for remote measurement of nitrogen oxides

    Directory of Open Access Journals (Sweden)

    K. Beier

    Full Text Available Infrared (IR molecular spectroscopy is proposed to perform remote measurements of NOx concentrations in the exhaust plume and wake of aircraft. The computer model NIRATAM is applied to simulate the physical and chemical properties of the exhaust plume and to generate low resolution IR spectra and synthetical thermal images of the aircraft in its natural surroundings. High-resolution IR spectra of the plume, including atmospheric absorption and emission, are simulated using the molecular line-by-line radiation model FASCODE2. Simulated IR spectra of a Boeing 747-400 at cruising altitude for different axial and radial positions in the jet region of the exhaust plume are presented. A number of spectral lines of NO can be identified that can be discriminated from lines of other exhaust gases and the natural atmospheric background in the region around 5.2 µm. These lines can be used to determine NO concentration profiles in the plume. The possibility of measuring nitrogen dioxide NO2 is also discussed briefly, although measurements turn out to be substantially less likely than those of NO. This feasibility study compiles fundamental data for the optical and radiometric design of an airborne Fourier transform spectrometer and the preparation of in-flight measurements for monitoring of aircraft pollutants.

  6. Modeling of aircraft exhaust emissions and infrared spectra for remote measurement of nitrogen oxides

    Directory of Open Access Journals (Sweden)

    K. Beier

    1994-08-01

    Full Text Available Infrared (IR molecular spectroscopy is proposed to perform remote measurements of NOx concentrations in the exhaust plume and wake of aircraft. The computer model NIRATAM is applied to simulate the physical and chemical properties of the exhaust plume and to generate low resolution IR spectra and synthetical thermal images of the aircraft in its natural surroundings. High-resolution IR spectra of the plume, including atmospheric absorption and emission, are simulated using the molecular line-by-line radiation model FASCODE2. Simulated IR spectra of a Boeing 747-400 at cruising altitude for different axial and radial positions in the jet region of the exhaust plume are presented. A number of spectral lines of NO can be identified that can be discriminated from lines of other exhaust gases and the natural atmospheric background in the region around 5.2 µm. These lines can be used to determine NO concentration profiles in the plume. The possibility of measuring nitrogen dioxide NO2 is also discussed briefly, although measurements turn out to be substantially less likely than those of NO. This feasibility study compiles fundamental data for the optical and radiometric design of an airborne Fourier transform spectrometer and the preparation of in-flight measurements for monitoring of aircraft pollutants.

  7. Rotor Systems of Aircraft Jet Engines

    Directory of Open Access Journals (Sweden)

    Ján Kamenický

    2000-01-01

    engine's both coaxial rotors, their supports (including their hydrodynamic dampers, and its casing as well. Besides the short description of the engine design peculiarities and of its calculating model, there is also a short description of the used method of calculations, with focus on its peculiarities as well. Finally, some results of calculations and conclusions that follow from them are presented.

  8. Altitude Compensating Nozzle

    Science.gov (United States)

    Ruf, Joseph H.; Jones, Daniel

    2015-01-01

    The dual-bell nozzle (fig. 1) is an altitude-compensating nozzle that has an inner contour consisting of two overlapped bells. At low altitudes, the dual-bell nozzle operates in mode 1, only utilizing the smaller, first bell of the nozzle. In mode 1, the nozzle flow separates from the wall at the inflection point between the two bell contours. As the vehicle reaches higher altitudes, the dual-bell nozzle flow transitions to mode 2, to flow full into the second, larger bell. This dual-mode operation allows near optimal expansion at two altitudes, enabling a higher mission average specific impulse (Isp) relative to that of a conventional, single-bell nozzle. Dual-bell nozzles have been studied analytically and subscale nozzle tests have been completed.1 This higher mission averaged Isp can provide up to a 5% increase2 in payload to orbit for existing launch vehicles. The next important step for the dual-bell nozzle is to confirm its potential in a relevant flight environment. Toward this end, NASA Marshall Space Flight Center (MSFC) and Armstrong Flight Research Center (AFRC) have been working to develop a subscale, hot-fire, dual-bell nozzle test article for flight testing on AFRC's F15-D flight test bed (figs. 2 and 3). Flight test data demonstrating a dual-bell ability to control the mode transition and result in a sufficient increase in a rocket's mission averaged Isp should help convince the launch service providers that the dual-bell nozzle would provide a return on the required investment to bring a dual-bell into flight operation. The Game Changing Department provided 0.2 FTE to ER42 for this effort in 2014.

  9. Weed detection using unmanned aircraft vehicles

    Directory of Open Access Journals (Sweden)

    Pflanz, Michael

    2014-03-01

    Full Text Available In contrast to agricultural remote sensing technologies, which are based on images from satellites or manned aircrafts, photogrammetry at low altitude from unmanned aircraft vehicles lead to higher spatial resolution, real-time processing and lower costs. Moreover multicopter aircrafts are suitable vehicles to perform precise path or stationary flights. In terms of vegetation photogrammetry this minimises motion blur and provide better image overlapping for stitching and mapping procedures. Through improved image analyses and through the recent increase in the availability of powerful batteries, microcontrollers and multispectral cameras, it can be expected in future that spatial mapping of weeds from low altitudes will be promoted. A small unmanned aircraft vehicle with a modified RGB camera was tested taking images from agricultural fields. A microcopter with six rotors was applied. The hexacopter in particular is GPS controlled and operates within predefined areas at given altitudes (from 5 to 10 m. Different scenarios of photogrammetrically weed detection have been carried out regarding to variable altitude, image resolution, weed and crop growth stages. First experiences with microcopter showed a high potential for site-specific weed control. Images analyses with regards to recognition of weed patches can be used to adapt herbicide applications to varying weed occurrence across a field.

  10. [Arterial hypertension due to altitude].

    Science.gov (United States)

    Domej, Wolfgang; Trapp, Michael; Miggitsch, Eva Maria; Krakher, Tiziana; Riedlbauer, Rita; Roher, Peter; Schwaberger, Günther

    2008-01-01

    The behavior of blood pressure under hypoxic conditions depends on individual factors, altitude and duration of stay at altitude. While most humans are normotensive at higher altitudes, a few will react with moderate hypertension or hypotension. Excessive elevation of arterial blood pressure is not even to be expected below 4,000 m. Rather, several weeks' stay at higher altitude will decrease systolic and diastolic blood pressure at rest as well as during physical exertion. A high-altitude treatment for rehabilitation purposes at moderate altitude may be recommended for patients with cardio-circulatory disorders. Improvements can last several months even after returning to accustomed altitudes. Furthermore, endurance-trained hypertensive patients with pharmacologically controlled arterial blood pressure might be able to participate in mountain treks without additional health risk.

  11. High-Altitude Platforms — Present Situation and Technology Trends

    OpenAIRE

    d’Oliveira, Flavio Araripe; Melo, Francisco Cristovão Lourenço de; Devezas, Tessaleno Campos

    2016-01-01

    ABSTRACT High-altitude platforms (HAPs) are aircraft, usually unmanned airships or airplanes positioned above 20 km, in the stratosphere, in order to compose a telecommunications network or perform remote sensing. In the 1990 and 2000 decades, several projects were launched, but very few had continued. In 2014, 2 major Internet companies (Google and Facebook) announced investments in new HAP projects to provide Internet access in regions without communication infrastructure (terrestrial or sa...

  12. The HAMMER: High altitude multiple mission environmental researcher

    Science.gov (United States)

    Hayashi, Darren; Zylla, Cara; Amaro, Ernesto; Colin, Phil; Klause, Thomas; Lopez, Bernardo; Williamson, Danna

    1991-01-01

    At the equator, the ozone layer ranges from 65,000 to 130,000+ feet which is beyond the capabilities of the ER-2, NASA's current high altitude reconnaissance aircraft. The Universities Space Research Association, in cooperation with NASA, is sponsoring an undergraduate program which is geared to designing an aircraft that can study the ozone layer at the equator. This aircraft must be able to satisfy four mission profiles. Mission one is a polar mission which ranges from Chile to the South Pole and back to Chile, a total range of 6000 n. mi. at 100,000 feet with a 2500 lb. payload. The second mission is also a polar mission with a decreased altitude of 70,000 feet and an increased payload of 4000 lb. For the third mission, the aircraft will take-off at NASA Ames, cruise at 100,000 feet carrying a 2500 lb. payload, and land in Puerto Montt, Chile. The final mission requires the aircraft to take-off at NASA Ames, cruise at 100,000 feet with a 1000 lb. payload, make an excursion to 120,000 feet, and land at Howard AFB, Panama. All three missions require that a subsonic Mach number is maintained due to constraints imposed by the air sampling equipment. The aircraft need not be manned for all four missions. Three aircraft configurations were determined to be the most suitable for meeting the above requirements. The performance of each configuration is analyzed to investigate the feasibility of the project requirements. In the event that a requirement can not be obtained within the given constraints, recommendations for proposal modifications are given.

  13. Successive leadership changes in the regional jet industry

    NARCIS (Netherlands)

    Vertesy, D.

    2014-01-01

    This study examines leadership dynamics in the regional jet manufacturing industry from the 1980s onwards. With the help of leading products (aircraft or aircraft family), British Aerospace (BAe), Fokker, Bombardier and Embraer consecutively took the leadership in terms of new deliveries. In order

  14. Boosted jets

    International Nuclear Information System (INIS)

    Juknevich, J.

    2014-01-01

    We present a study of the substructure of jets high transverse momentum at hadron colliders. A template method is introduced to distinguish heavy jets by comparing their energy distributions to the distributions of a set of templates which describe the kinematical information from signal or background. As an application, a search for a boosted Higgs boson decaying into bottom quarks in association with a leptonically decaying W boson is presented as well. (author)

  15. Advanced thermally stable jet fuels

    Energy Technology Data Exchange (ETDEWEB)

    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. Emerging Jets

    CERN Document Server

    Schwaller, Pedro; Weiler, Andreas

    2015-01-01

    In this work, we propose a novel search strategy for new physics at the LHC that utilizes calorimeter jets that (i) are composed dominantly of displaced tracks and (ii) have many different vertices within the jet cone. Such emerging jet signatures are smoking guns for models with a composite dark sector where a parton shower in the dark sector is followed by displaced decays of dark pions back to SM jets. No current LHC searches are sensitive to this type of phenomenology. We perform a detailed simulation for a benchmark signal with two regular and two emerging jets, and present and implement strategies to suppress QCD backgrounds by up to six orders of magnitude. At the 14 TeV LHC, this signature can be probed with mediator masses as large as 1.5 TeV for a range of dark pion lifetimes, and the reach is increased further at the high-luminosity LHC. The emerging jet search is also sensitive to a broad class of long-lived phenomena, and we show this for a supersymmetric model with R-parity violation. Possibilit...

  17. Emerging jets

    Energy Technology Data Exchange (ETDEWEB)

    Schwaller, Pedro; Stolarski, Daniel [European Organization for Nuclear Research (CERN), Geneva (Switzerland). TH-PH Div.; Weiler, Andreas [European Organization for Nuclear Research (CERN), Geneva (Switzerland). TH-PH Div.; Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2015-02-15

    In this work, we propose a novel search strategy for new physics at the LHC that utilizes calorimeter jets that (i) are composed dominantly of displaced tracks and (ii) have many different vertices within the jet cone. Such emerging jet signatures are smoking guns for models with a composite dark sector where a parton shower in the dark sector is followed by displaced decays of dark pions back to SM jets. No current LHC searches are sensitive to this type of phenomenology. We perform a detailed simulation for a benchmark signal with two regular and two emerging jets, and present and implement strategies to suppress QCD backgrounds by up to six orders of magnitude. At the 14 TeV LHC, this signature can be probed with mediator masses as large as 1.5 TeV for a range of dark pion lifetimes, and the reach is increased further at the high-luminosity LHC. The emerging jet search is also sensitive to a broad class of long-lived phenomena, and we show this for a supersymmetric model with R-parity violation. Possibilities for discovery at LHCb are also discussed.

  18. Emerging jets

    International Nuclear Information System (INIS)

    Schwaller, Pedro; Stolarski, Daniel

    2015-02-01

    In this work, we propose a novel search strategy for new physics at the LHC that utilizes calorimeter jets that (i) are composed dominantly of displaced tracks and (ii) have many different vertices within the jet cone. Such emerging jet signatures are smoking guns for models with a composite dark sector where a parton shower in the dark sector is followed by displaced decays of dark pions back to SM jets. No current LHC searches are sensitive to this type of phenomenology. We perform a detailed simulation for a benchmark signal with two regular and two emerging jets, and present and implement strategies to suppress QCD backgrounds by up to six orders of magnitude. At the 14 TeV LHC, this signature can be probed with mediator masses as large as 1.5 TeV for a range of dark pion lifetimes, and the reach is increased further at the high-luminosity LHC. The emerging jet search is also sensitive to a broad class of long-lived phenomena, and we show this for a supersymmetric model with R-parity violation. Possibilities for discovery at LHCb are also discussed.

  19. Brain Food at High Altitude.

    Science.gov (United States)

    Jain, Vishal

    2016-01-01

    Scenic view at high altitude is a pleasure to the eyes, but it has some shortcoming effects as well. High altitude can be divided into different categories, i.e., high altitude (3000-5000 ft), very high altitude (5000-8000 ft), and extreme altitude (above 8000 ft). Much of the population resides at high altitude, and others go there for tourism. Military personnel are also posted there to defend boundaries. As we ascent to high altitude, partial pressure of oxygen reduces, whereas concentration remains the same; this reduces the availability of oxygen to different body parts. This pathophysiological condition is known as hypobaric hypoxia (HH) which leads to oxidative stress and further causes cognitive dysfunction in some cases. Hypoxia causes neurodegeneration in different brain regions; however, the hippocampus is found to be more prone in comparison to other brain regions. As the hippocampus is affected most, therefore, spatial memory is impaired most during such condition. This chapter will give a brief review of the damaging effect of high altitude on cognition and also throw light on possible herbal interventions at high altitude, which can improve cognitive performance as well as provide protection against the deteriorating effect of hypobaric hypoxia at high altitude.

  20. Amphibious Aircraft

    Data.gov (United States)

    National Aeronautics and Space Administration — A brief self composed research article on Amphibious Aircrafts discussing their use, origin and modern day applications along with their advantages and disadvantages...

  1. Investigation of Radiation Fields at Aircraft Altitudes (invited paper)

    International Nuclear Information System (INIS)

    O'Sullivan, D.; Bartlett, D.; Grillmaier, R.; Heinrich, W.; Lindborg, L.; Schraube, H.; Silari, M.; Tommasino, L.; Zhou, D.

    2000-01-01

    Cosmic rays are believed to originate from several possible sources and recent research suggests that the bulk originate from the gas and dust of the interstellar medium and are accelerated by strong shock waves driven by supernova explosions. Cosmic ray particles are made up of γ98.5% hydrogen and helium and only 1.5% have charges greater than 2. Their average energy is about 1 GeV/nucleon and they lose energy through ionisation interactions and nuclear interactions with atoms of air as they penetrate deeply into the Earth's atmosphere. A very complicated radiation field develops as particles are generated by successive interaction of primary and secondary nuclei and a cascade of hadrons is produced in the atmosphere. The intensity of particles reaches a maximum at about 20 km above sea level (γ60 g.cm -2 ). The relative abundances of different particles change with depth within the atmosphere and mainly muons which are the decay products of charged mesons, reach sea level because of their weak interaction. The radiation field produced and consequently its effect on aircrew and frequent travellers is a matter of some concern. This paper outlines the results of investigations carried out to determine the characteristics of this radiation field and assess its impact on aircrew. (author)

  2. SR-71B - in Flight with F-18 Chase Aircraft - View from Air Force Tanker

    Science.gov (United States)

    1996-01-01

    for the Linear Aerospike Rocket Engine, or LASRE Experiment. Another earlier project consisted of a series of flights using the SR-71 as a science camera platform for NASA's Jet Propulsion Laboratory in Pasadena, California. An upward-looking ultraviolet video camera placed in the SR-71's nosebay studied a variety of celestial objects in wavelengths that are blocked to ground-based astronomers. Earlier in its history, Dryden had a decade of past experience at sustained speeds above Mach 3. Two YF-12A aircraft and an SR-71 designated as a YF-12C were flown at the center between December 1969 and November 1979 in a joint NASA/USAF program to learn more about the capabilities and limitations of high-speed, high-altitude flight. The YF-12As were prototypes of a planned interceptor aircraft based on a design that later evolved into the SR-71 reconnaissance aircraft. Dave Lux was the NASA SR-71 project manger for much of the decade of the 1990s, followed by Steve Schmidt. Developed for the USAF as reconnaissance aircraft more than 30 years ago, SR-71s are still the world's fastest and highest-flying production aircraft. The aircraft can fly at speeds of more than 2,200 miles per hour (Mach 3+, or more than three times the speed of sound) and at altitudes of over 85,000 feet. The Lockheed Skunk Works (now Lockheed Martin) built the original SR-71 aircraft. Each aircraft is 107.4 feet long, has a wingspan of 55.6 feet, and is 18.5 feet high (from the ground to the top of the rudders, when parked). Gross takeoff weight is about 140,000 pounds, including a possible fuel weight of 80,280 pounds. The airframes are built almost entirely of titanium and titanium alloys to withstand heat generated by sustained Mach 3 flight. Aerodynamic control surfaces consist of all-moving vertical tail surfaces, ailerons on the outer wings, and elevators on the trailing edges between the engine exhaust nozzles. The two SR-71s at Dryden have been assigned the following NASA tail numbers: NASA 844

  3. Simulation Packages Expand Aircraft Design Options

    Science.gov (United States)

    2013-01-01

    In 2001, NASA released a new approach to computational fluid dynamics that allows users to perform automated analysis on complex vehicle designs. In 2010, Palo Alto, California-based Desktop Aeronautics acquired a license from Ames Research Center to sell the technology. Today, the product assists organizations in the design of subsonic aircraft, space planes, spacecraft, and high speed commercial jets.

  4. Tests of the Daimler D-IVa Engine at a High Altitude Test Bench

    Science.gov (United States)

    Noack, W G

    1920-01-01

    Reports of tests of a Daimler IVa engine at the test-bench at Friedrichshafen, show that the decrease of power of that engine, at high altitudes, was established, and that the manner of its working when air is supplied at a certain pressure was explained. These tests were preparatory to the installation of compressors in giant aircraft for the purpose of maintaining constant power at high altitudes.

  5. Cosmic rays with portable Geiger counters: from sea level to airplane cruise altitudes

    Energy Technology Data Exchange (ETDEWEB)

    Blanco, Francesco; La Rocca, Paola; Riggi, Francesco [Department of Physics and Astronomy, University of Catania, Via S. Sofia 64, I-95123 Catania (Italy)], E-mail: Francesco.Riggi@ct.infn.it

    2009-07-15

    Cosmic ray count rates with a set of portable Geiger counters were measured at different altitudes on the way to a mountain top and aboard an aircraft, between sea level and cruise altitude. Basic measurements may constitute an educational activity even with high school teams. For the understanding of the results obtained, simulations of extensive air showers induced by high-energy primary protons in the atmosphere were also carried out, involving undergraduate and graduate teaching levels.

  6. Chemical composition and photochemical reactivity of exhaust from aircraft turbine engines

    Directory of Open Access Journals (Sweden)

    T. F. Lyon

    Full Text Available Assessment of the environmental impact of aircraft emissions is required by planners and policy makers. Seveal areas of concern are: 1. exposure of airport workers and urban residents to toxic chemicals emitted when the engines operate at low power (idle and taxi on the ground; 2. contributions to urban photochemical air pollution of aircraft volatile organic and nitrogen oxides emissions from operations around airports; and 3. emissions of nitrogen oxides and particles during high-altitude operation. The environmental impact of chemicals emitted from jet aircraft turbine engines has not been firmly established due to lack of data regarding emission rates and identities of the compounds emitted. This paper describes an experimental study of two different aircraft turbine engines designed to determine detailed organic emissions, as well as emissions of inorganic gases. Emissions were measured at several engine power settings. Measurements were made of detailed organic composition from C1 through C17, CO, CO2, NO, NOx, and polycyclic aromatic hydrocarbons. Measurements were made using a multi-port sampling pro be positioned directly behind the engine in the exhaust exit plane. The emission measurements have been used to determine the organic distribution by carbon number and the distribution by compound class at each engine power level. The sum of the organic species was compared with an independent measurement of total organic carbon to assess the carbon mass balance. A portion of the exhaust was captured and irradiated in outdoor smog chambers to assess the photochemical reactivity of the emissions with respect to ozone formation. The reactivity of emissions from the two engines was apportioned by chemical compound class.

  7. Chemical composition and photochemical reactivity of exhaust from aircraft turbine engines

    Directory of Open Access Journals (Sweden)

    C. W. Spicer

    1994-08-01

    Full Text Available Assessment of the environmental impact of aircraft emissions is required by planners and policy makers. Seveal areas of concern are: 1. exposure of airport workers and urban residents to toxic chemicals emitted when the engines operate at low power (idle and taxi on the ground; 2. contributions to urban photochemical air pollution of aircraft volatile organic and nitrogen oxides emissions from operations around airports; and 3. emissions of nitrogen oxides and particles during high-altitude operation. The environmental impact of chemicals emitted from jet aircraft turbine engines has not been firmly established due to lack of data regarding emission rates and identities of the compounds emitted. This paper describes an experimental study of two different aircraft turbine engines designed to determine detailed organic emissions, as well as emissions of inorganic gases. Emissions were measured at several engine power settings. Measurements were made of detailed organic composition from C1 through C17, CO, CO2, NO, NOx, and polycyclic aromatic hydrocarbons. Measurements were made using a multi-port sampling pro be positioned directly behind the engine in the exhaust exit plane. The emission measurements have been used to determine the organic distribution by carbon number and the distribution by compound class at each engine power level. The sum of the organic species was compared with an independent measurement of total organic carbon to assess the carbon mass balance. A portion of the exhaust was captured and irradiated in outdoor smog chambers to assess the photochemical reactivity of the emissions with respect to ozone formation. The reactivity of emissions from the two engines was apportioned by chemical compound class.

  8. Isothermal and Reactive Turbulent Jets in Cross-Flow

    Science.gov (United States)

    Gutmark, Ephraim; Bush, Scott; Ibrahim, Irene

    2004-11-01

    Jets in cross flow have numerous applications including vertical/short takeoff/landing (V/STOL) aircraft, cooling jets for gas turbine blades and combustion air supply inlets in gas turbine engine. The properties exhibited by these jets are dictated by complex three dimensional turbulence structures which form due to the interaction of the jet with the freestream. The isothermal tests are conducted in a wind tunnel measuring the characteristics of air jets injected perpendicular into an otherwise undisturbed air stream. Different nozzle exit geometries of the air jets were tested including circular, triangular and elongated configurations. Jets are injected in single and paired combinations with other jets to measure the effect of mutual interaction on the parameters mentioned. Quantitative velocity fields are obtained using PIV. The data obtained allows the extraction of flow parameters such as jet structure, penetration and mixing. The reacting tests include separate and combined jets of fuel/air mixture utilized to explore the stabilization of combustion at various operating conditions. Different geometrical configurations of transverse jets are tested to determine the shape and combination of jets that will optimize the jets ability to successfully stabilize a flame.

  9. Training at altitude in practice.

    Science.gov (United States)

    Dick, F W

    1992-10-01

    There can be little doubt that training at altitude is fundamental to preparing an athlete for competition at altitude. However the value of training at altitude for competition at sea level appears on the one hand to lack total acceptance amongst sports scientists; and on the other to hold some cloak of mystery for coaches who have yet to enjoy first hand experience. The fact is that very few endurance athletes will ignore the critical edge which altitude training affords. Each fraction of a percentage of performance advantage gained through methods which are within the rules of fair play in sport, may shift the balance between failure and achievement. Moreover, there is growing support for application of training at altitude for speed-related disciplines. This paper aims to demystify the subject by dealing with practical aspects of training at altitude. Such aspects include a checklist of what should and should not be done at altitude, when to use altitude relative to target competitions, and specific training examples.

  10. Dosimetric significance of cosmic radiation in the altitude of SST and in free space

    Energy Technology Data Exchange (ETDEWEB)

    Allkofer, O C [Kiel Univ. (Germany, F.R.). Inst. fuer Reine und Angewandte Kernphysik

    1977-01-01

    The integral cosmic-ray flux, and hence the dose rate, increases with altitude. At the cruising altitude of the subsonic jets, about 10 km, the dose rate is already about a factor 70 higher than at sea level. At the higher altitudes of SST the situation is different because the composition of the galactic component differs from that at the subsonic level, the solar flares are more efficient, and a small number of heavy nuclei are still present. In free space an additional radiation hazard appears when the radiation belts have to be crossed.

  11. Aircraft Carriers

    DEFF Research Database (Denmark)

    Nødskov, Kim; Kværnø, Ole

    as their purchases of aircraft carrier systems, makes it more than likely that the country is preparing such an acquisition. China has territorial disputes in the South China Sea over the Spratly Islands and is also worried about the security of its sea lines of communications, by which China transports the majority......, submarines, aircraft and helicopters, is not likely to be fully operational and war-capable until 2020, given the fact that China is starting from a clean sheet of paper. The United States of America (USA), the United Kingdom (UK), Russia and India are currently building or have made decisions to build new...

  12. High altitude dermatology

    Directory of Open Access Journals (Sweden)

    G K Singh

    2017-01-01

    Full Text Available Approximately, 140 million people worldwide live permanently at high altitudes (HAs and approximately another 40 million people travel to HA area (HAA every year for reasons of occupation, sports or recreation. In India, whole of Ladakh region, part of Northwest Kashmir, Northern part of Sikkim and Tenga valley of Arunachal are considered inhabited areas of HAA. The low quantity of oxygen, high exposure of ultraviolet (UV light, very low humidity, extreme subzero temperature in winter, high wind velocity, make this region difficult for lowlanders as well as for tourists. Acute mountain sickness, HA pulmonary edema, HA cerebral edema, and thromboembolic conditions are known to occur in HA. However, enough knowledge has not been shared on dermatoses peculiar to this region. Xerosis, UV-related skin disorders (tanning, photomelanosis, acute and chronic sunburn, polymorphic light eruption, chronic actinic dermatitis, actinic cheilitis, etc., cold injuries (frostbite, chilblains, acrocyanosis, erythrocyanosis, etc. nail changes (koilonychias, airborne contact dermatitis, insect bite reaction, and skin carcinoma (basal cell carcinomas, squamous cell carcinomas, and also rarely malignant melanoma are the dermatoses seen in HAAs. Early diagnosis and knowledge of HA dermatoses may prevent serious consequences of disease and improve the quality of life for the visitors as well as for native of the place.

  13. Conversion of the dual training aircraft (DC into single control advanced training aircraft (SC. Part I

    Directory of Open Access Journals (Sweden)

    Ioan ŞTEFĂNESCU

    2011-03-01

    Full Text Available Converting the DC school jet aircraft into SC advanced training aircraft - and use them forthe combat training of military pilots from the operational units, has become a necessity due to thebudget cuts for Air Force, with direct implications on reducing the number of hours of flight assignedto operating personnel for preparing and training.The purpose of adopting such a program is to reduce the number of flight hours allocated annuallyfor preparing and training in advanced stages of instruction, for every pilot, by more intensive use ofthis type of aircraft, which has the advantage of lower flight hour costs as compared to a supersoniccombat plane.

  14. Aircraft cybernetics

    Science.gov (United States)

    1977-01-01

    The use of computers for aircraft control, flight simulation, and inertial navigation is explored. The man-machine relation problem in aviation is addressed. Simple and self-adapting autopilots are described and the assets and liabilities of digital navigation techniques are assessed.

  15. Investigation of Separation Control in Low Pressure Turbine Using Pulsed Vortex Generator Jets (Postprint)

    National Research Council Canada - National Science Library

    Woods, N; Boxx, I; Sondergaard, R; McQuilling, M; Wolf, M

    2006-01-01

    ...) injected over the suction surface of the Pack-B turbine blade is reported. Blade Reynolds numbers in the turbine cascade match those that occur in aircraft engines while at high altitude cruise...

  16. Satellite images to aircraft in flight. [GEOS image transmission feasibility analysis

    Science.gov (United States)

    Camp, D.; Luers, J. K.; Kadlec, P. W.

    1977-01-01

    A study has been initiated to evaluate the feasibility of transmitting selected GOES images to aircraft in flight. Pertinent observations that could be made from satellite images on board aircraft include jet stream activity, cloud/wind motion, cloud temperatures, tropical storm activity, and location of severe weather. The basic features of the Satellite Aircraft Flight Environment System (SAFES) are described. This system uses East GOES and West GOES satellite images, which are interpreted, enhanced, and then retransmitted to designated aircraft.

  17. Properties of Supersonic Impinging Jets

    Science.gov (United States)

    Alvi, F. S.; Iyer, K. G.; Ladd, J.

    1999-11-01

    A detailed study examining the behavior of axisymmetric supersonic jets impinging on a ground plane is described. Our objective is to better understand the aeroacoustics governing this complex flowfield which commonly occurs in the vicinity of STOVL aircraft. Flow issuing through a Mach 1.5 C-D and a converging sonic nozzle is examined over a wide parametric range. For some cases a large diameter circular 'lift' plate, with an annular hole through which the jet is issued, is attached at the nozzle exit to simulate a generic airframe. The impinging jet flowfield was examined using Particle Image Velocimetry (PIV), which provides the velocity field for the entire region and shadowgraph visualization techniques. Near-field acoustic, as well as, mean and unsteady pressure measurements on the ground and lift plate surfaces were also obtained. The velocity field data, together with the surface flow measurements have resulted in a much better understanding of this flow from a fundamental standpoint while also identifying critical regions of interest for practical applications. Some of these findings include the presence of a stagnation bubble with recirculating flow; a very high speed (transonic/supersonic) radial wall jet; presence of large, spatially coherent turbulent structures in the primary jet and wall jet and high unsteady loads on the ground plane and lift plates. The results of a companion CFD investigation and its comparison to the experimental data will also be presented. Very good agreement has been found between the computational and experimental results thus providing confidence in the development of computational tools for the study of such flows.

  18. Documentation of Atmospheric Conditions During Observed Rising Aircraft Wakes

    Science.gov (United States)

    Zak, J. Allen; Rodgers, William G., Jr.

    1997-01-01

    Flight tests were conducted in the fall of 1995 off the coast of Wallops Island, Virginia in order to determine characteristics of wake vortices at flight altitudes. A NASA Wallops Flight Facility C130 aircraft equipped with smoke generators produced visible wakes at altitudes ranging from 775 to 2225 m in a variety of atmospheric conditions, orientations (head wind, cross wind), and airspeeds. Meteorological and aircraft parameters were collected continuously from a Langley Research Center OV-10A aircraft as it flew alongside and through the wake vortices at varying distances behind the C130. Meteorological data were also obtained from special balloon observations made at Wallops. Differential GPS capabilities were on each aircraft from which accurate altitude profiles were obtained. Vortices were observed to rise at distances beyond a mile behind the C130. The maximum altitude was 150 m above the C130 in a near neutral atmosphere with significant turbulence. This occurred from large vertical oscillations in the wakes. There were several cases when vortices did not descend after a very short initial period and remained near generation altitude in a variety of moderately stable atmospheres and wind shears.

  19. ARMAS and NAIRAS Comparisons of Radiation at Aviation Altitudes

    Science.gov (United States)

    Bell, L. D.

    2015-12-01

    Space Environment Technologies and the Space Weather Center (SWC) at Utah State University are deploying and obtaining effective dose rate radiation data from dosimeters flown on research aircraft. This project is called Automated Radiation Measurements for Aerospace Safety (ARMAS). Through several dozen flights since 2013 the ARMAS project has successfully demonstrated the operation of a micro-dosimeter on commercial aviation altitude aircraft that captures the real-time radiation environment resulting from galactic cosmic rays (GCR's) and solar energetic particles (SEP's). Space weather effects upon the near Earth environment are to dynamic changes in the energy transfer process from the Sun's photons, particles, and fields. The coupling between the solar and galactic high-energy particles, and atmospheric regions can significantly affect human tissue and the aircrafts technology as a result of radiation exposure. We describe and compare the types of radiation we have been measuring with the NAIRAS global climatological model as it relates to human tissue susceptibility and as a source at different altitude regions.

  20. Technology for reducing aircraft engine pollution

    Science.gov (United States)

    Rudey, R. A.; Kempke, E. E., Jr.

    1975-01-01

    Programs have been initiated by NASA to develop and demonstrate advanced technology for reducing aircraft gas turbine and piston engine pollutant emissions. These programs encompass engines currently in use for a wide variety of aircraft from widebody-jets to general aviation. Emission goals for these programs are consistent with the established EPA standards. Full-scale engine demonstrations of the most promising pollutant reduction techniques are planned within the next three years. Preliminary tests of advanced technology gas turbine engine combustors indicate that significant reductions in all major pollutant emissions should be attainable in present generation aircraft engines without adverse effects on fuel consumption. Fundamental-type programs are yielding results which indicate that future generation gas turbine aircraft engines may be able to utilize extremely low pollutant emission combustion systems.

  1. Acute high-altitude sickness

    Directory of Open Access Journals (Sweden)

    Andrew M. Luks

    2017-02-01

    Full Text Available At any point 1–5 days following ascent to altitudes ≥2500 m, individuals are at risk of developing one of three forms of acute altitude illness: acute mountain sickness, a syndrome of nonspecific symptoms including headache, lassitude, dizziness and nausea; high-altitude cerebral oedema, a potentially fatal illness characterised by ataxia, decreased consciousness and characteristic changes on magnetic resonance imaging; and high-altitude pulmonary oedema, a noncardiogenic form of pulmonary oedema resulting from excessive hypoxic pulmonary vasoconstriction which can be fatal if not recognised and treated promptly. This review provides detailed information about each of these important clinical entities. After reviewing the clinical features, epidemiology and current understanding of the pathophysiology of each disorder, we describe the current pharmacological and nonpharmacological approaches to the prevention and treatment of these diseases.

  2. Commercial jet fuel quality control

    Energy Technology Data Exchange (ETDEWEB)

    Strauss, K.H.

    1995-05-01

    The paper discusses the purpose of jet fuel quality control between the refinery and the aircraft. It describes fixed equipment, including various types of filters, and the usefulness and limitations of this equipment. Test equipment is reviewed as are various surveillance procedures. These include the Air Transport Association specification ATA 103, the FAA Advisory Circular 150/5230-4, the International Air Transport Association Guidance Material for Fuel Quality Control and Fuelling Service and the Guidelines for Quality Control at Jointly Operated Fuel Systems. Some past and current quality control problems are briefly mentioned.

  3. Altitude training improves glycemic control.

    Science.gov (United States)

    Chen, Shu-Man; Lin, Hsueh-Yi; Kuo, Chia-Hua

    2013-08-31

    Under altitude hypoxia condition, energy reliance on anaerobic glycolysis increases to compensate the shortfall caused by reduced fatty acid oxidation. Short-term moderate altitude exposure plus endurance physical activity has been found to improve glucose tolerance (not fasting glucose) in humans, which is associated with the improvement in the whole-body insulin sensitivity. However, most of people cannot accommodate high altitude exposure above 4500 M due to acute mountain sickness and insulin resistance. There is a wide variation among individuals in response to the altitude challenge. In particular, the improvement in glucose tolerance and insulin sensitivity by prolonged altitude hiking activity was not apparent in those individuals with low baseline dehydroepiandrosterone sulfate (DHEA-S) concentration. In rats, exercise training recovery under prolonged hypoxia exposure (14-15% oxygen, 8 h per day for 6 weeks) can also improve insulin sensitivity, secondary to an effective suppression of adiposity. After prolonged hypoxia training, obese abnormality in upregulated baseline levels of AMP-activated protein kinase (AMPK) and AS160 phosphorylation in skeletal muscle can be reversed. In humans, moderate hypoxia increases postprandial blood distribution towards skeletal muscle during a training recovery. This physiological response plays a role in the redistribution of fuel storage among important energy storage sites and may explain its potent effect on the favorable change in body composition. Altitude training can exert strong impact on our metabolic system, and has the potential to be designed as a non-pharmacological or recreational intervention regimen for correcting metabolic syndromes.

  4. A comparative analysis of the influence of weather on the flight altitudes of birds

    NARCIS (Netherlands)

    Shamoun-Baranes, J.; van Loon, E.; van Gasteren, H.; van Belle, J.; Bouten, W.; Buurma, L.

    2006-01-01

    Birds pose a serious risk to flight safety worldwide. A Bird Avoidance Model (BAM) is being developed in the Netherlands to reduce the risk of bird-aircraft collisions. In order to develop a temporally and spatially dynamic model of bird densities, data are needed on the flight-altitude distribution

  5. System for beaming power from earth to a high altitude platform

    Science.gov (United States)

    Friedman, Herbert W.; Porter, Terry J.

    2002-01-01

    Power is transmitted to a high altitude platform by an array of diode pumped solid state lasers each operated at a single range of laser wavelengths outside of infrared and without using adaptive optics. Each laser produces a beam with a desired arrival spot size. An aircraft avoidance system uses a radar system for automatic control of the shutters of the lasers.

  6. Long-range pollution transport during the MILAGRO-2006 campaign: a case study of a major Mexico City outflow event using free-floating altitude-controlled balloons

    Directory of Open Access Journals (Sweden)

    P. B. Voss

    2010-08-01

    Full Text Available One of the major objectives of the Megacities Initiative: Local And Global Research Observations (MILAGRO-2006 campaign was to investigate the long-range transport of polluted Mexico City Metropolitan Area (MCMA outflow and determine its downwind impacts on air quality and climate. Six research aircraft, including the National Center for Atmospheric Research (NCAR C-130, made extensive chemical, aerosol, and radiation measurements above MCMA and more than 1000 km downwind in order to characterize the evolution of the outflow as it aged and dispersed over the Mesa Alta, Sierra Madre Oriental, Coastal Plain, and Gulf of Mexico. As part of this effort, free-floating Controlled-Meteorological (CMET balloons, commanded to change altitude via satellite, made repeated profile measurements of winds and state variables within the advecting outflow. In this paper, we present an analysis of the data from two CMET balloons that were launched near Mexico City on the afternoon of 18 March 2006 and floated downwind with the MCMA pollution for nearly 30 h. The repeating profile measurements show the evolving structure of the outflow in considerable detail: its stability and stratification, interaction with other air masses, mixing episodes, and dispersion into the regional background. Air parcel trajectories, computed directly from the balloon wind profiles, show three transport pathways on 18–19 March: (a high-altitude advection of the top of the MCMA mixed layer, (b mid-level outflow over the Sierra Madre Oriental followed by decoupling and isolated transport over the Gulf of Mexico, and (c low-level outflow with entrainment into a cleaner northwesterly jet above the Coastal Plain. The C-130 aircraft intercepted the balloon-based trajectories three times on 19 March, once along each of these pathways; in all three cases, peaks in urban tracer concentrations and LIDAR backscatter are consistent with MCMA pollution. In comparison with the transport models

  7. Integrating the Unmanned Aircraft System into the National Airspace System

    Science.gov (United States)

    2011-06-18

    HALE High Altitude Long Endurance IFR Instrument Flight Rules ISR Intelligence, Surveillance, and Reconnaissance JFC Joint Force Commander JP...many advantages and disadvantages of unmanned aircraft now made national headlines as UAS executed missions, once reserved for manned aircraft...of this research. To operate above 18,000 feet MSL the UAS must be filed under Instrument Flight Rules, or IFR flight plan. Additionally, the

  8. Damage Tolerant Repair Techniques for Pressurized Aircraft Fuselages

    Science.gov (United States)

    1994-01-01

    RepoW Techniques for Prwurized Aircraft AXWdOg 4.9 Summary and Conclusions The basics of adhesive bonded repairs for aluminum aircraft fuselages have... of cruise altitude and bending stresses in the plate at the tip of one-sided reinforcements (chapter 5). The expanded Rose model was transformed into a...DEPARTMEN1 OF THE AIR FORCE AGENCY REPORT NUMBER AFIT/CI 2950 P STREET WRIGHT-PATTERSON AFB OH 45433-7765 11. SUPPLEMENTARY NOTES Usa. DISTRUISUIOII

  9. Unmanned Aircraft Systems Roadmap, 2005-2030

    Science.gov (United States)

    2005-01-01

    UCAV Unmanned Combat Air Vehicle ISS Integrated Sensor Suite UCS Unmanned Control System ITU International Telecommunications Union UFO UHF...RDC) at Groton, CT. These have included alien and drug interdiction along the Texas coast and in the Caribbean, UA launch and recovery systems...altitude aircraft and UA; and narrowband services to support mobile and handheld services as a replacement or follow-on for the UHF Follow-On ( UFO

  10. Proceedings of the Jet Noise Workshop

    Science.gov (United States)

    Huff, Dennis (Compiler)

    2001-01-01

    Jet noise has been a major problem for aircraft for nearly 50 years. There has been considerable research performed around the world aimed at identifying ways to reduce jet noise. This work was first intended for turbojet aircraft and later extended to low bypass ratio turbofans. Many of the people who performed this pioneering research have retired or are no longer active in aeroacoustics. After so many years of work in jet noise, it is a challenge to piece together the history of its development through existing publications due to the large volume of documents. It is possible to forget important developments from the past as new researchers tackle similar problems. Therefore, a jet noise workshop was organized by the AeroAcoustics Research Consortium (AARC) with the intent of reviewing research that has been done by experts throughout the world. The forum provided a unique opportunity for current researchers to hear the diverse views from world experts on issues related to jet noise modeling and interpretation of experimental data.

  11. Modeling of Air Attenuation Effects on Gamma Detection at Altitude

    International Nuclear Information System (INIS)

    Detwiler, R. S.

    2002-01-01

    This paper focuses on modeling the detection capabilities of NaI sensor systems at high altitudes for ground sources. The modeling was done with the Monte Carlo N-Transport (MCNP) code developed at Los Alamos National Laboratory. The specific systems modeled were the fixed wing and helicopter aircraft sensor systems, assets of the U. S. Department of Energy's National Nuclear Security Administration Nevada Operations Office (NNSA/NV) Aerial Measuring System (AMS). In previous (2001) modeling, Sodium Iodine (NaI) detector responses were simulated for both point and distributed surface sources as a function of gamma energy and altitude. For point sources, photo-peak efficiencies were calculated for a zero radial distance and an offset equal to the altitude. For distributed sources approximating an infinite plane, gross count efficiencies were calculated and normalized to a uniform surface deposition of 1 (micro)Ci/m 2 . To validate the calculations, benchmark measurements were made for simple source-detector configurations. The 2002 continuation of the modeling presented here includes checking models against available data, and modifications to allow more effective and accurate directional biasing of ground point and distributed sources. Fixed-wing data results will be shown for two point sources as a function of altitude

  12. A Comparitive Analysis of the Influence of Weather on the Flight Altitudes of Birds.

    Science.gov (United States)

    Shamoun-Baranes, Judy; van Loon, Emiel; van Gasteren, Hans; van Belle, Jelmer; Bouten, Willem; Buurma, Luit

    2006-01-01

    Birds pose a serious risk to flight safety worldwide. A Bird Avoidance Model (BAM) is being developed in the Netherlands to reduce the risk of bird aircraft collisions. In order to develop a temporally and spatially dynamic model of bird densities, data are needed on the flight-altitude distribution of birds and how this is influenced by weather. This study focuses on the dynamics of flight altitudes of several species of birds during local flights over land in relation to meteorological conditions.We measured flight altitudes of several species in the southeastern Netherlands using tracking radar during spring and summer 2000. Representatives of different flight strategy groups included four species: a soaring species (buzzard ), an obligatory aerial forager (swift Apus apus), a flapping and gliding species (blackheaded gull Larus ridibundus), and a flapping species (starling Sturnus vulgaris).Maximum flight altitudes varied among species, during the day and among days. Weather significantly influenced the flight altitudes of all species studied. Factors such as temperature, relative humidity, atmospheric instability, cloud cover, and sea level pressure were related to flight altitudes. Different combinations of factors explained 40% 70% of the variance in maximum flight altitudes. Weather affected flight strategy groups differently. Compared to flapping species, buzzards and swifts showed stronger variations in maximum daily altitude and f lew higher under conditions reflecting stronger thermal convection. The dynamic vertical distributions of birds are important for risk assessment and mitigation measures in flight safety as well as wind turbine studies.

  13. Optimizing height presentation for aircraft cockpit displays

    Science.gov (United States)

    Jordan, Chris S.; Croft, D.; Selcon, Stephen J.; Markin, H.; Jackson, M.

    1997-02-01

    This paper describes an experiment conducted to investigate the type of display symbology that most effectively conveys height information to users of head-down plan-view radar displays. The experiment also investigated the use of multiple information sources (redundancy) in the design of such displays. Subjects were presented with eight different height display formats. These formats were constructed from a control, and/or one, two, or three sources of redundant information. The three formats were letter coding, analogue scaling, and toggling (spatially switching the position of the height information from above to below the aircraft symbol). Subjects were required to indicate altitude awareness via a four-key, forced-choice keyboard response. Error scores and response times were taken as performance measures. There were three main findings. First, there was a significant performance advantage when the altitude information was presented above and below the symbol to aid the representation of height information. Second, the analogue scale, a line whose length indicated altitude, proved significantly detrimental to performance. Finally, no relationship was found between the number of redundant information sources employed and performance. The implications for future aircraft and displays are discussed in relation to current aircraft tactical displays and in the context of perceptual psychological theory.

  14. Jet Car Track Site

    Data.gov (United States)

    Federal Laboratory Consortium — Located in Lakehurst, New Jersey, the Jet Car Track Site supports jet cars with J57 engines and has a maximum jet car thrust of 42,000 pounds with a maximum speed of...

  15. Jet Crackle

    Science.gov (United States)

    2015-06-23

    crackle is correlated to signals with intermittent periods of steepened shock-like waves followed by weaker, longer, rounded rarefaction regions, but to...turbulence is concentrated in a weakly curved (for a typical round jet) shear layer between the high-speed potential core flow and the surrounding co-flow...decreases into the acoustic field. The effect of varying dc between −0.1 and −0.003δm(t)/∆U causes the Nδm/Lx curves to shift downward as fewer waves

  16. Jet Noise Modeling for Supersonic Business Jet Application

    Science.gov (United States)

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

    2004-01-01

    This document describes the development of an improved predictive model for coannular jet noise, including noise suppression modifications applicable to small supersonic-cruise aircraft such as the Supersonic Business Jet (SBJ), for NASA Langley Research Center (LaRC). For such aircraft a wide range of propulsion and integration options are under consideration. Thus there is a need for very versatile design tools, including a noise prediction model. The approach used is similar to that used with great success by the Modern Technologies Corporation (MTC) in developing a noise prediction model for two-dimensional mixer ejector (2DME) nozzles under the High Speed Research Program and in developing a more recent model for coannular nozzles over a wide range of conditions. If highly suppressed configurations are ultimately required, the 2DME model is expected to provide reasonable prediction for these smaller scales, although this has not been demonstrated. It is considered likely that more modest suppression approaches, such as dual stream nozzles featuring chevron or chute suppressors, perhaps in conjunction with inverted velocity profiles (IVP), will be sufficient for the SBJ.

  17. Simulation model for the Boeing 720B aircraft-flight control system in continuous flight.

    Science.gov (United States)

    1971-08-01

    A mathematical model of the Boeing 720B aircraft and autopilot has been derived. The model is representative of the 720B aircraft for continuous flight within a flight envelope defined by a Mach number of .4 at 20,000 feet altitude in a cruise config...

  18. High-altitude pulmonary hypertension

    Directory of Open Access Journals (Sweden)

    X-Q. Xu

    2009-03-01

    Full Text Available High-altitude pulmonary hypertension (HAPH is a specific disease affecting populations that live at high elevations. The prevalence of HAPH among those residing at high altitudes needs to be further defined. Whereas reduction in nitric oxide production may be one mechanism for the development of HAPH, the roles of endothelin-1 and prostaglandin I2 pathways in the pathogenesis of HAPH deserve further study. Although some studies have suggested that genetic factors contribute to the pathogenesis of HAPH, data published to date are insufficient for the identification of a significant number of gene polymorphims in HAPH. The clinical presentation of HAPH is nonspecific. Exertional dyspnoea is the most common symptom and signs related to right heart failure are common in late stages of HAPH. Echocardiography is the most useful screening tool and right heart catheterisation is the gold standard for the diagnosis of HAPH. The ideal management for HAPH is migration to lower altitudes. Phosphodiesterase 5 is an attractive drug target for the treatment of HAPH. In addition, acetazolamide is a promising therapeutic agent for high-altitude pulmonary hypertension. To date, no evidence has confirmed whether endothelin-receptor antagonists have efficacy in the treatment of high-altitude pulmonary hypertension.

  19. Potential for Fuel Tank Fire and Hydrodynamic Ram from Uncontained Aircraft Engine Debris

    Science.gov (United States)

    1997-01-01

    This report addresses the potential consequences of the impact and penetration of fuel tanks by debris from uncontained engine failures on commercial jet aircraft. The report presents a brief review of accident data and of the pertinent technical lit...

  20. Certification and safety aspects relating to the transport of passengers on high altitude balloons in Europe

    Science.gov (United States)

    Schoenmaker, Annelie

    2014-07-01

    High-altitude balloons typically fly between 25 and 50 km in altitude, which, while below the Karman line of 100 km, is yet far above the altitudes typically flown by aircraft. For example, the highest-flying commercial aircraft - the Concorde - had a maximum cruising altitude of only 18 km. zero2infinity, a Spanish company, is currently developing a pressurized pod named “bloon” which will be capable of lifting six people, including two pilot crew members and four paying passengers, to an altitude of 36 km through the use of high-altitude balloons. The boundary between Airspace and Outer Space has never been legally defined, mostly because of the lack of activities taking place between the altitude where airplanes fly and the lowest orbiting spacecraft. High-altitude balloons do fly at these in-between altitudes and the prospect of commercializing access to these parts of the stratosphere poses some questions in a new light. Given the relatively low altitude at which they fly, it may well be that these types of balloons would be considered to operate exclusively within air space. However, given the technology involved in crewed high altitude balloon flights, which is more similar to spacecraft engineering than to traditional hot-air or gas ballooning, it is necessary to evaluate the various legal regimes, codes, and regulations that would apply to such flights, especially regarding licenses and liabilities. For high altitude balloon flights commencing in Europe, the European Aviation Safety Agency (EASA) would very likely be the competent certification or licensing agency for these flights, although there would likely be input from various national aviation authorities as well. However, because the European Commission (EC) has not yet issued regulations regarding commercial spaceflight, particularly the use of high altitude balloons, new rules and regulations governing such flights may still need to be drafted and promulgated. With the development of

  1. Data Quality Assurance for Supersonic Jet Noise Measurements

    Science.gov (United States)

    Brown, Clifford A.; Henderson, Brenda S.; Bridges, James E.

    2010-01-01

    The noise created by a supersonic aircraft is a primary concern in the design of future high-speed planes. The jet noise reduction technologies required on these aircraft will be developed using scale-models mounted to experimental jet rigs designed to simulate the exhaust gases from a full-scale jet engine. The jet noise data collected in these experiments must accurately predict the noise levels produced by the full-scale hardware in order to be a useful development tool. A methodology has been adopted at the NASA Glenn Research Center s Aero-Acoustic Propulsion Laboratory to insure the quality of the supersonic jet noise data acquired from the facility s High Flow Jet Exit Rig so that it can be used to develop future nozzle technologies that reduce supersonic jet noise. The methodology relies on mitigating extraneous noise sources, examining the impact of measurement location on the acoustic results, and investigating the facility independence of the measurements. The methodology is documented here as a basis for validating future improvements and its limitations are noted so that they do not affect the data analysis. Maintaining a high quality jet noise laboratory is an ongoing process. By carefully examining the data produced and continually following this methodology, data quality can be maintained and improved over time.

  2. Atmospheric/climatic effects of aircraft emissions

    International Nuclear Information System (INIS)

    Pueschel, R.F.

    1996-01-01

    Exhaust emissions from aircraft include oxides of nitrogen (NO x ), water vapor (H 2 O), sulfur dioxide (SO 2 ), carbon dioxide (CO 2 ), carbon monoxide (CO), hydrocarbons (HC) and particles (soot and sulfates). These emissions are small compared to industrial/urban surface emissions. However, because (1) atmospheric residence times of exhaust constituents are longer at altitude, particularly in the stratosphere, than they are in the boundary layer, (2) their background concentrations at altitude are lower than those near the surface, (3) the radiation balance is the more sensitive to atmospheric trace constituents the colder the temperature aloft and (4) inter-hemispheric mixing of aircraft effluents is inhibited, aircraft emissions near and above the tropopause and polewards of 40 degrees latitude can be environmentally critical. That's why atmospheric/climatic effects of aircraft emissions have again received scientific, economic and political scrutiny in the last few years, motivated by growth of subsonic traffic at about 5% per year over the past two decades and the advent of a technologically feasible operation of a supersonic high speed commercial transport (HSCT) fleet

  3. Daedalus Project's Light Eagle - Human powered aircraft

    Science.gov (United States)

    1987-01-01

    autopilot that could be used on high altitude or human powered aircraft, and determining the power required to fly the Daedalus aircraft. The research flights began in late December 1987 with a shake-down of the Light Eagle instrumentation and data transfer links. The first flight of the Daedalus 87 also occurred during this time. On February 7, 1988, the Daedalus 87 aircraft crashed on Rogers Dry Lakebed. The Daedalus 88, which later set the world record, was then shipped from MIT to replace the 87's research flights, and for general checkout procedures. Due to the accident, flight testing was extended four weeks and thus ended in mid-March 1988 after having achieved the major goals of the program; exploring the dynamics of low Reynolds number aircraft, and investigating the aeroelastic behavior of lightweight aircraft. The information obtained from this program had direct applications to the later design of many high-altitude, long endurance aircraft.

  4. Military Tactical Aircraft Engine Noise Matching to Infrared Signatures

    Science.gov (United States)

    2016-12-16

    Jet engine exhaust plumes also exhibit emission and absorption of radiation from their emitted chemical species, occurring at discrete spectra...Modulation,” Naval Postgraduate School MS thesis (1990). [8] Sinha, N., Ungewitter, R. J., Kenzakowski, D. C., and Seiner, J. M., “Gas Turbine Engine Jet...FINAL REPORT Military Tactical Aircraft Engine Noise Matching to Infrared Signatures SERDP Project WP-2404 JANUARY 2016 Dr

  5. Meeting the challenges with the Douglas Aircraft Company Aeroelastic Design Optimization Program (ADOP)

    Science.gov (United States)

    Rommel, Bruce A.

    1989-01-01

    An overview of the Aeroelastic Design Optimization Program (ADOP) at the Douglas Aircraft Company is given. A pilot test program involving the animation of mode shapes with solid rendering as well as wire frame displays, a complete aircraft model of a high-altitude hypersonic aircraft to test ADOP procedures, a flap model, and an aero-mesh modeler for doublet lattice aerodynamics are discussed.

  6. Aircraft Emissions: Potential Effects on Ozone and Climate - A Review and Progress Report

    Science.gov (United States)

    1977-03-01

    course, continued researc leads to con- vergence of fact and theory. In this area, such continued research is clearly PI essential. In reporting on...with supersonic aircraft operating higher than subsonic aircraft; geo- r~I graphical distribution depends on the markets served. All these factors change...noted above, altitude and geogp’aphical distribution of emissions depends on the types of aircraft assumed and markets served. The aggregation of

  7. Visualization of synthetic jet formation in air

    Czech Academy of Sciences Publication Activity Database

    Trávníček, Zdeněk; Broučková, Zuzana; Kordík, Jozef; Vít, T.

    2015-01-01

    Roč. 18, č. 4 (2015), s. 595-609 ISSN 1343-8875 R&D Projects: GA ČR GA14-08888S Institutional support: RVO:61388998 Keywords : synthetic jet * flow visualization * hot-wire anemometry Subject RIV: JU - Aeronautics, Aerodynamics, Aircrafts Impact factor: 0.720, year: 2015 http://link.springer.com/article/10.1007/s12650-015-0273-2

  8. Visualization study of hybrid synthetic jets

    Czech Academy of Sciences Publication Activity Database

    Broučková, Zuzana; Trávníček, Zdeněk

    2015-01-01

    Roč. 18, č. 4 (2015), s. 581-593 ISSN 1343-8875 R&D Projects: GA ČR GA14-08888S Institutional support: RVO:61388998 Keywords : synthetic jet * efficiency * flow visualization Subject RIV: JU - Aeronautics, Aerodynamics, Aircrafts Impact factor: 0.720, year: 2015 http://link.springer.com/article/10.1007/s12650-014-0256-8

  9. Intriguing radiation signatures at aviation altitudes

    Science.gov (United States)

    Tobiska, W. K.

    2017-12-01

    The Automated Radiation Measurements for Aerospace Safety (ARMAS) project captures absorbed dose in Si with a fleet of 6 instruments on research aircraft. These dose rates are then converted to an effective dose rate. Over 325 flights since 2013 have captured global radiation at nearly all altitudes and latitudes. The radiation is predominantly caused by atmospheric neutrons and protons from galactic cosmic rays (GCRs). We have not yet obtained dose from solar energetic particle (SEP) events, which are rather rare. On 13 flights we have also measured dose rates that are up to twice the GCR background for approximately a half an hour per event while flying at higher magnetic latitudes near 60 degrees. The timing of the radiation appears to be coincident with periods of mild geomagnetic disturbances while flying above 10 km at L-shells of 3 to 6. The radiation source is best modeled as secondary gamma-ray photons caused by precipitating ultra-relativistic electrons from the outer Van Allen radiation belt originating as loss cone electrons scattered by electromagnetic ion cyclotron (EMIC) waves. We describe the observations and the lines of evidence for this intriguing new radiation source relevant to aviation crew and frequent flyers.

  10. High-performance-vehicle technology. [fighter aircraft propulsion

    Science.gov (United States)

    Povinelli, L. A.

    1979-01-01

    Propulsion needs of high performance military aircraft are discussed. Inlet performance, nozzle performance and cooling, and afterburner performance are covered. It is concluded that nonaxisymmetric nozzles provide cleaner external lines and enhanced maneuverability, but the internal flows are more complex. Swirl afterburners show promise for enhanced performance in the high altitude, low Mach number region.

  11. Gust load estimation and rejection with application to robust flight control design for HALE aircraft, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — High Altitude Long Endurance (HALE) aircraft have garnered increased interest in recent years as they can serve several purposes, including many of the objectives of...

  12. Jet inclusive cross sections

    International Nuclear Information System (INIS)

    Del Duca, V.

    1992-11-01

    Minijet production in jet inclusive cross sections at hadron colliders, with large rapidity intervals between the tagged jets, is evaluated by using the BFKL pomeron. We describe the jet inclusive cross section for an arbitrary number of tagged jets, and show that it behaves like a system of coupled pomerons

  13. First observations of Gigantic Jets from Monsoon Thunderstorms over India

    Science.gov (United States)

    Singh, Rajesh; Maurya, Ajeet; Chanrion, Olivier; Neubert, Torsten; Cummer, Steven; Mlynarczyk, Janusz; Bór, József; Siingh, Devendraa; Cohen, Morris; Kumar, Sushil

    2016-04-01

    Gigantic Jets are electric discharges from thunderstorm cloud tops to the bottom of the ionosphere at ~80 km altitude. After their first discovery in 2001, relatively few observations have been reported. Most of these are from satellites at large distances and a few tens from the ground at higher spatial resolution. Here we report the first Gigantic Jets observed in India from two thunderstorm systems that developed over the land surface from monsoon activity, each storm producing two Gigantic Jets. The jets were recorded by a video camera system at standard video rate (20 ms exposure) at a few hundred km distance. ELF measurements suggest that the jets are of the usual negative polarity and that they develop in less than 40 ms, which is faster than most jets reported in the past. The jets originate from the leading edge of a slowly drifting convective cloud complex close to the highest regions of the clouds and carry ~25 Coulomb of charge to the ionosphere. One jet has a markedly horizontal displacement that we suggest is caused by a combination of close-range cloud electric fields at inception, and longer-range cloud fields at larger distances during full development. The Gigantic Jets are amongst the few that have been observed over land.

  14. Modeling Jet Interaction of a Round Jet with a Subsonic Carrying Flow

    Directory of Open Access Journals (Sweden)

    Yu. P. Korobkova

    2017-01-01

    Full Text Available The paper analyzes numerical simulation of the round jet with a subsonic carrying flow. Performs calculations for different tilt angles of the jet ωj blowing and constructs the fields of velocities and pressures of the flow, jet trajectory, as well as calculates the pressure coefficients on the plate surface.To solve this problem, the CAD Solidworks Flow Simulation software was used. This package contains the solution of the Nowier-Stokes equation, which is necessary for modeling this problem.To test operation capability of the closing condition (k-th model of turbulence and proper choice of the boundaries of the computational domain, was solved a test problem forThe solution analysis has shown that the k-th model of turbulence was capable, and has a good agreement with other authors' experiment results [4]. Based on the selected conditions, further calculations were carried out for different tilt angles of jet blowing.In the course of research activities, it was revealed that the tilt angle of the jet blowing has a strong impact on redistribution of velocity and pressure in the area of the jet interaction, which allows the efficient use of such jets to control aerodynamic characteristics of the aircraft with the same power consumption for blowing out the gas. The solution of this problem is very relevant in wide application in aviation and rocket and space technology.

  15. Joint Technical Coordinating Group on Aircraft Survivability (JTCG/AS). Bibliography of Joint Aircraft Survivability Reports

    Science.gov (United States)

    2000-07-01

    PMSG ). Report No.: JTCG/AS-99-D-003 Report Classification: UNCLASSIFIED Title: JTCG/AS Bibliography of Joint Aircraft Survivability Reports and...indicates those approved and not approved for funding by the Principal Members Steering Group ( PMSG ). Report No.: Report Classification: JTCG/AS-97-V-010...demonstrated by additional tests conducted at NWSC/Crane (up to Mach 0.8) and Rockwell International wind tunnel (up to Mach 1/9 and 30,000 feet altitude

  16. Numerical study of nozzle design for the hybrid synthetic jet actuator

    Czech Academy of Sciences Publication Activity Database

    Hsu, S.-S.; Chou, Y.-J.; Trávníček, Zdeněk; Lin, C.-F.; Wang, A. B.; Yen, R.H.

    2015-01-01

    Roč. 232, August (2015), s. 172-182 ISSN 0924-4247 R&D Projects: GA ČR GA14-08888S Institutional support: RVO:61388998 Keywords : synthetic jet * hybrid synthetic jet * numerical simulation Subject RIV: JU - Aeronautics, Aerodynamics, Aircrafts Impact factor: 2.201, year: 2015 http://www.sciencedirect.com/science/article/pii/S0924424715300091

  17. Maximization of integral outlet quantities of an axisymmetric synthetic jet actuator based on a loudspeaker

    Czech Academy of Sciences Publication Activity Database

    Kordík, Jozef; Trávníček, Zdeněk

    2016-01-01

    Roč. 114, March (2016), č. článku 02152. ISSN 2101-6275. [International Conference on Experimental Fluid Mechanics /10./. Praha, 17.11.2015-20.11.2015] R&D Projects: GA ČR GA14-08888S Institutional support: RVO:61388998 Keywords : synthetic jet * synthetic jet actuator * resonance Subject RIV: JU - Aeronautics, Aerodynamics, Aircrafts

  18. PIV and LIF study of slot continuous jet at low Reynolds number

    Czech Academy of Sciences Publication Activity Database

    Broučková, Zuzana; Hsu, S.S.; Wang, A. B.; Trávníček, Zdeněk

    2016-01-01

    Roč. 114, March (2016), č. článku 02007. ISSN 2101-6275. [International Conference on Experimental Fluid Mechanics /10./. Praha, 17.11.2015-20.11.2015] R&D Projects: GA ČR GA14-08888S Institutional support: RVO:61388998 Keywords : continuous jet * slot jet * particle image velocimetry Subject RIV: JU - Aeronautics, Aerodynamics, Aircrafts

  19. Jet Joint Undertaking

    International Nuclear Information System (INIS)

    Keen, B.E.; O'Hara, G.W.; Pollard, I.E.

    1988-07-01

    The paper presents the Jet Joint Undertaking annual report 1987. A description is given of the JET and Euratom and International Fusion Programmes. The technical status of JET is outlined, including the development and improvements made to the system in 1987. The results of JET Operation in 1987 are described within the areas of: density effects, temperature improvements, energy confinement studies and other material effects. The contents also contain a summary of the future programme of JET. (U.K.)

  20. 3D flow organization and dynamics in subsonic jets : Aeroacoustic source analysis by tomographic PIV

    NARCIS (Netherlands)

    Violato, D.V.

    2013-01-01

    To meet the increasingly stringent noise regulation, aircraft manufacturers are searching for solutions to jet noise. This, which constitutes a significant amount of the total noise emitted by civil aircrafts, is generated by the mixing processes between the exhaust flow leaving the engine and the

  1. Environmental Assessment for the Beddown of C-17 Aircraft at March Air Reserve Base, California

    Science.gov (United States)

    2003-02-01

    chickens up to ten weeks were not affected by exposure to various sound intensities of reproduced jet aircraft noise (Manci et al. 1988). Pregnancy ...training areas proposed fo.r C-l7 aircraft uti lization include tbe Air Force Plant No. 42 (Palmdale) and Desert Center Zoue, which are located near

  2. Characteristics of polar coronal hole jets

    Science.gov (United States)

    Chandrashekhar, K.; Bemporad, A.; Banerjee, D.; Gupta, G. R.; Teriaca, L.

    2014-01-01

    Context. High spatial- and temporal-resolution images of coronal hole regions show a dynamical environment where mass flows and jets are frequently observed. These jets are believed to be important for the coronal heating and the acceleration of the fast solar wind. Aims: We studied the dynamics of two jets seen in a polar coronal hole with a combination of imaging from EIS and XRT onboard Hinode. We observed drift motions related to the evolution and formation of these small-scale jets, which we tried to model as well. Methods: Stack plots were used to find the drift and flow speeds of the jets. A toymodel was developed by assuming that the observed jet is generated by a sequence of single reconnection events where single unresolved blobs of plasma are ejected along open field lines, then expand and fall back along the same path, following a simple ballistic motion. Results: We found observational evidence that supports the idea that polar jets are very likely produced by multiple small-scale reconnections occurring at different times in different locations. These eject plasma blobs that flow up and down with a motion very similar to a simple ballistic motion. The associated drift speed of the first jet is estimated to be ≈27 km s-1. The average outward speed of the first jet is ≈171 km s-1, well below the escape speed, hence if simple ballistic motion is considered, the plasma will not escape the Sun. The second jet was observed in the south polar coronal hole with three XRT filters, namely, C-poly, Al-poly, and Al-mesh filters. Many small-scale (≈3″-5″) fast (≈200-300 km s-1) ejections of plasma were observed on the same day; they propagated outwards. We observed that the stronger jet drifted at all altitudes along the jet with the same drift speed of ≃7 km s-1. We also observed that the bright point associated with the first jet is a part of sigmoid structure. The time of appearance of the sigmoid and that of the ejection of plasma from the bright

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

    Science.gov (United States)

    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.

  4. Responses of Raptorial Birds to Low Level Military Jets and Sonic Booms: Results of the 1980-1981 Joint U.S. Air Force-U.S. Fish and Wildlife Service Study

    Science.gov (United States)

    Ellis, D.H.

    1981-01-01

    Summary: For this study, we gathered several kinds of data to determine the likely effects of low level jets and sonic booms on nesting Peregrine Falcons and other raptors. We directly observed responses to worst case stimulus loads: responses to extremely frequent and extremely nearby jet aircraft were often minimal, seldom significant and never associated with reproductive failure. Likewise, responses to real and simulated sonic booms were often minimal and never productivity limiting. In addition to directly observing behavioral responses, in 1981 we invited jet passes at four Prairie Falcon eyries during courtship and incubation when the adults were most likely to abandon, on an ad libitum basis. All four eyries fledged young. Nesting success and site reoccupancy rates were high for all eyries. In tests of two relatively naive captive Peregrine Falcons, we failed to detect significantly negative responses. Typically the birds either quickly resumed feeding or other activities within a few seconds following a pass or boom. The female falcon repeatedly made hunting forays as jets swept overhead. From heart rate (HR) data taken via a telemetering egg during incubation at a wild Prairie Falcon eyrie, we determined that stimulus induced HR alterations were comparable to rate changes of the birds settling to incubate following flight. No significant long term responses were identified. The falcons successfully fledged two young even with the more disruptive activities associated with entering the eyrie three times to position and recover the telemetering eggs. Significantly, birds ofprey of several genera commonly nest in the supersonic military operations areas in southern Arizona. In addition, raptor eyries are frequently found at locations where low level jet traffic naturally concentrates. For example, Prairie Falcon Site 11 is directly on the approach path to strafing and bombing targets. Prairie Falcon Site 1 is in a narrow canyon through which A-10 aircraft

  5. Longterm monitoring of ambient dose equivalent rates at aviation altitudes

    Energy Technology Data Exchange (ETDEWEB)

    Heber, B.; Burmeister, S.; Moeller, T.; Scharrenberg, E. [Institut fuer Experimentelle und Angewandte Physik, Christian-Albrechts-Universitaet zu Kiel, Kiel (Germany); Briese, J. [Deutsche Lufthansa AG, Frankfurt am Main (Germany); Burda, O.; Klages, T.; Langner, F.; Marquardt, J.; Wissmann, F. [Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig Germany (Germany); Matthiae, D.; Reitz, G. [German Aerospace Center, Institute of Aerospace Medicine, Linder Hoehe, 51147 Koeln (Germany)

    2012-07-01

    The complex radiation field at flight altitudes results mainly from the interaction of energetic charged particles with atmospheric molecules and atoms and consists of secondary neutrons, protons, gamma rays, electrons, positrons and muons. Due to the continuous interactions of primary and secondary particles within the atmosphere, the intensity of each component depends on the height. Since the Earth's magnetic field acts as rigidity filter for the charged primary particles, the flux of the primary particles into the atmosphere and the resulting intensity of secondary particles depend on the geomagnetic latitude being highest over the geomagnetic poles. The main primary component consists of Galactic Cosmic Rays (GCRs), mainly protons and alpha particles, whose flux is modulated in the heliosphere. Beside this slowly varying galactic component, solar energetic particle events may temporarily increase the intensity of this radiation field. In the frame of the Radiation Monitoring on Board Aircraft (RAMONA) collaboration, three NAVIgation and DOSimetry (NAVIDOS) systems were installed in 2008 and 2009 on board of three Lufthansa Airbus A340 aircraft. They have been maintained since then by the consortium. Two of the NAVIDOS units rely on the DOSimetry TELescopes (DOSTELs), one is based on a LIULIN detector. This unique setup is ideally suited to investigate variations in the radiation field at different flight altitudes and geomagnetic positions and has been used to measure the radiation exposure during the recent extended solar minimum and thereafter. With increasing solar activity in 2010 the measured dose rates have been decreasing. Since these variations depend on the location of the aircraft, a detailed data analysis is required and presented.

  6. Kajian Teknologi High Altitude Platform (HAP [Study of High Altitude Platform (HAP Technology

    Directory of Open Access Journals (Sweden)

    Amry Daulat Gultom

    2016-07-01

    Full Text Available High Altitude Platform (HAP merupakan solusi alternatif untuk mengatasi keterbatasan infrastruktur terestrial maupun satelit. HAP merupakan pesawat ataupun balon udara yang ditempatkan pada ketinggian 20-50 km di atas permukaan bumi. Kelebihan yang utama dari HAP adalah kemudahan dalam penempatan, fleksibilitas, biaya operasionalnya rendah, delay  propagasi rendah, sudut elevasi lebar, cakupan yang luas. Penelitian ini dilakukan untuk mengetahui potensi HAP untuk komunikasi pita lebar dan perkembangannya di Indonesia. Analisis dilakukan secara deskriptif dengan mengolah data literatur yang didapat. Hasil penelitian menunjukkan bahwa di Indonesia terdapat potensi teknologi HAP untuk komunikasi pita lebar dengan lebar pita 2x300 MHz di band 27,9-28,2 GHz dan 31-31,3 GHz. Namun, belum ada peraturan yang mengatur alokasi frekuensi untuk HAP secara khusus di Indonesia.*****High Altitude Platform (HAP has been developed as an alternative solution in order to overcome limitation of terrestrial and satellite communication system. HAP is an aircraft or balloon situated on 20-50 km above the earth. Main advantages of HAP are flexibility in deployment, low propagation delay, wide elevation angle and broad coverage. The research is conducted to gather HAP potential for broadband communication and its development in Indonesia. Analysis is conducted by descriptive analysis from literature study gather. The research result shows that in Indonesia, there is potential of HAP technology for broadband communication with 2x300 MHz bandwidth within 27,9-28,2 GHz and 31-31,3 GHz. Yet, there are no specific regulations managing frequency allocation for HAP in Indonesia.

  7. Radiation exposure and high-altitude flight. NCRP Commentary No. 12

    International Nuclear Information System (INIS)

    1995-01-01

    Enhanced air crew and public radiation exposure while flying at current altitudes and speeds has not been adequately addressed. However, the commercial aircraft industry continues to expand with greater numbers of passengers and more air crews year by year. With the expected expansions in high-altitude flight in the next two decades there will be many more people exposed to higher levels of ionizing radiation than currently. The equivalent dose rates at the higher altitudes are of the order of two to three times those received at current aircraft altitudes, but are not known very well, partly because of limitations in the knowledge of the component radiations, especially the high-energy neutron component. The risks are also more uncertain than for low-LET exposures on the ground because of uncertainty in an average W R to use for high-LET radiations. Exposures of current air crew are presently comparable with the average exposures of other radiation workers on the ground (EPA, 1995). Substantially higher exposures must be expected at high altitudes to air crew (perhaps approaching or possibly exceeding the current limit for workers on the ground). Higher exposures to sensitive groups of the population such as the fetuses carried by pregnant women are of special concern. Therefore, steps must be taken to improve our knowledge base with respect to dose levels and risks at these high altitudes. Following acquisition of this knowledge, modifications in radiation protection practices with respect to air crew and passengers will need to be considered and recommended to assure that adequate radiation protection is provided with respect to high-altitude flight

  8. Vector boson tagged jets and jet substructure

    Directory of Open Access Journals (Sweden)

    Vitev Ivan

    2018-01-01

    Full Text Available In these proceedings, we report on recent results related to vector boson-tagged jet production in heavy ion collisions and the related modification of jet substructure, such as jet shapes and jet momentum sharing distributions. Z0-tagging and γ-tagging of jets provides new opportunities to study parton shower formation and propagation in the quark-gluon plasma and has been argued to provide tight constrains on the energy loss of reconstructed jets. We present theoretical predictions for isolated photon-tagged and electroweak boson-tagged jet production in Pb+Pb collisions at √sNN = 5.02 TeV at the LHC, addressing the modification of their transverse momentum and transverse momentum imbalance distributions. Comparison to recent ATLAS and CMS experimental measurements is performed that can shed light on the medium-induced radiative corrections and energy dissipation due to collisional processes of predominantly quark-initiated jets. The modification of parton splitting functions in the QGP further implies that the substructure of jets in heavy ion collisions may differ significantly from the corresponding substructure in proton-proton collisions. Two such observables and the implication of tagging on their evaluation is also discussed.

  9. Toward Active Control of Noise from Hot Supersonic Jets

    Science.gov (United States)

    2012-11-15

    et al. (2011a), the Mach number chosen for this study is not typical of commercial or military aircraft engines, and bears little relevance to most...CHRISTOPHER K. W., VISWANATHAN, K., AHUJA, K. K. & PANDA , J. 2008 The sources of jet noise: experimental evidence. J. Fluid Mech. 615, 253-292. TANNA, H. K

  10. Understanding jet noise.

    Science.gov (United States)

    Karabasov, S A

    2010-08-13

    Jets are one of the most fascinating topics in fluid mechanics. For aeronautics, turbulent jet-noise modelling is particularly challenging, not only because of the poor understanding of high Reynolds number turbulence, but also because of the extremely low acoustic efficiency of high-speed jets. Turbulent jet-noise models starting from the classical Lighthill acoustic analogy to state-of-the art models were considered. No attempt was made to present any complete overview of jet-noise theories. Instead, the aim was to emphasize the importance of sound generation and mean-flow propagation effects, as well as their interference, for the understanding and prediction of jet noise.

  11. Very forward jet, Mueller Navelet jets and jet gap jet measurements in CMS

    CERN Document Server

    Cerci, Salim

    2018-01-01

    The measurements of very forward jet, Mueller-Navelet jets and jet-gap-jet events are presented for different collision energies. The analyses are based on data collected with the CMS detector at the LHC. Jets are defined through the anti-$k_\\mathrm{t}$ clustering algorithm for different cone sizes. Jet production studies provide stringent tests of quantum chromodynamics (QCD) and contribute to tune Monte Carlo (MC) simulations and phenomenological models. The measurements are compared to predictions from various Monte Carlo event generators.

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

    Science.gov (United States)

    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.

  13. Aurora Flight Sciences' Perseus B Remotely Piloted Aircraft in Flight

    Science.gov (United States)

    1998-01-01

    A long, slender wing and a pusher propeller at the rear characterize the Perseus B remotely piloted research aircraft, seen here during a test flight in June 1998. Perseus B is a remotely piloted aircraft developed as a design-performance testbed under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) project. Perseus is one of several flight vehicles involved in the ERAST project. A piston engine, propeller-powered aircraft, Perseus was designed and built by Aurora Flight Sciences Corporation, Manassas, Virginia. The objectives of Perseus B's ERAST flight tests have been to reach and maintain horizontal flight above altitudes of 60,000 feet and demonstrate the capability to fly missions lasting from 8 to 24 hours, depending on payload and altitude requirements. The Perseus B aircraft established an unofficial altitude record for a single-engine, propeller-driven, remotely piloted aircraft on June 27, 1998. It reached an altitude of 60,280 feet. In 1999, several modifications were made to the Perseus aircraft including engine, avionics, and flight-control-system improvements. These improvements were evaluated in a series of operational readiness and test missions at the Dryden Flight Research Center, Edwards, California. Perseus is a high-wing monoplane with a conventional tail design. Its narrow, straight, high-aspect-ratio wing is mounted atop the fuselage. The aircraft is pusher-designed with the propeller mounted in the rear. This design allows for interchangeable scientific-instrument payloads to be placed in the forward fuselage. The design also allows for unobstructed airflow to the sensors and other devices mounted in the payload compartment. The Perseus B that underwent test and development in 1999 was the third generation of the Perseus design, which began with the Perseus Proof-Of-Concept aircraft. Perseus was initially developed as part of NASA's Small High-Altitude Science Aircraft (SHASA) program, which later evolved into the ERAST

  14. Propulsion controlled aircraft computer

    Science.gov (United States)

    Cogan, Bruce R. (Inventor)

    2010-01-01

    A low-cost, easily retrofit Propulsion Controlled Aircraft (PCA) system for use on a wide range of commercial and military aircraft consists of an propulsion controlled aircraft computer that reads in aircraft data including aircraft state, pilot commands and other related data, calculates aircraft throttle position for a given maneuver commanded by the pilot, and then displays both current and calculated throttle position on a cockpit display to show the pilot where to move throttles to achieve the commanded maneuver, or is automatically sent digitally to command the engines directly.

  15. Aircraft vulnerability analysis by modeling and simulation

    Science.gov (United States)

    Willers, Cornelius J.; Willers, Maria S.; de Waal, Alta

    2014-10-01

    Infrared missiles pose a significant threat to civilian and military aviation. ManPADS missiles are especially dangerous in the hands of rogue and undisciplined forces. Yet, not all the launched missiles hit their targets; the miss being either attributable to misuse of the weapon or to missile performance restrictions. This paper analyses some of the factors affecting aircraft vulnerability and demonstrates a structured analysis of the risk and aircraft vulnerability problem. The aircraft-missile engagement is a complex series of events, many of which are only partially understood. Aircraft and missile designers focus on the optimal design and performance of their respective systems, often testing only in a limited set of scenarios. Most missiles react to the contrast intensity, but the variability of the background is rarely considered. Finally, the vulnerability of the aircraft depends jointly on the missile's performance and the doctrine governing the missile's launch. These factors are considered in a holistic investigation. The view direction, altitude, time of day, sun position, latitude/longitude and terrain determine the background against which the aircraft is observed. Especially high gradients in sky radiance occur around the sun and on the horizon. This paper considers uncluttered background scenes (uniform terrain and clear sky) and presents examples of background radiance at all view angles across a sphere around the sensor. A detailed geometrical and spatially distributed radiometric model is used to model the aircraft. This model provides the signature at all possible view angles across the sphere around the aircraft. The signature is determined in absolute terms (no background) and in contrast terms (with background). It is shown that the background significantly affects the contrast signature as observed by the missile sensor. A simplified missile model is constructed by defining the thrust and mass profiles, maximum seeker tracking rate, maximum

  16. Feasibility study for a microwave-powered ozone sniffer aircraft. B.S. Thesis

    Science.gov (United States)

    Botros, David F.; Cody, Charlotte K.; Forden, Noah P.; Helsing, Martin A.; Jutras, Thomas H.; Kim, Dohoon; Labarre, Christopher; Odin, Ethan M.; Sandler, Scott B.

    1990-01-01

    The preliminary design of a high-altitude, remotely-piloted, atmospheric-sampling aircraft powered by microwave energy beamed from ground-based antenna was completed. The vehicle has a gross weight of 6720 pounds and is sized to carry a 1000 pound payload at an altitude of 100,000 feet. The underside of the wing serves as the surface of a rectenna designed to receive microwave energy at a power density of 700 watts per square meter and the wing has a planform area of 3634 square feet to absorb the required power at an optimum Mach number M = 0.44. The aircraft utilizes a horizontal tail and a canard for longitudinal control and to enhance the structural rigidity of the twin fuselage configuration. The wing structure is designed to withstand a gust-induced load factor n = 3 at cruise altitude but the low-wing loading of the aircraft makes it very sensitive to gusts at low altitudes, which may induce load factors in excess of 20. A structural load alleviation system is therefore proposed to limit actual loads to the designed structural limit. Losses will require transmitted power on the order of megawatts to be radiated to the aircraft from the ground station, presenting environmental problems. Since the transmitting antenna would have a diameter of several hundred feet, it would not be readily transportable, so we propose that a single antenna be constructed at a site from which the aircraft is flown. The aircraft would be towed aloft to an initial altitude at which the microwave power would be utilized. The aircraft would climb to cruise altitude in a spiral flight path and orbit the transmitter in a gentle turn.

  17. Database on aircraft accidents

    International Nuclear Information System (INIS)

    Nishio, Masahide; Koriyama, Tamio

    2013-11-01

    The Reactor Safety Subcommittee in the Nuclear Safety and Preservation Committee published 'The criteria on assessment of probability of aircraft crash into light water reactor facilities' as the standard method for evaluating probability of aircraft crash into nuclear reactor facilities in July 2002. In response to this issue, Japan Nuclear Energy Safety Organization has been collecting open information on aircraft accidents of commercial airplanes, self-defense force (SDF) airplanes and US force airplanes every year since 2003, sorting out them and developing the database of aircraft accidents for the latest 20 years to evaluate probability of aircraft crash into nuclear reactor facilities. In this report the database was revised by adding aircraft accidents in 2011 to the existing database and deleting aircraft accidents in 1991 from it, resulting in development of the revised 2012 database for the latest 20 years from 1992 to 2011. Furthermore, the flight information on commercial aircrafts was also collected to develop the flight database for the latest 20 years from 1992 to 2011 to evaluate probability of aircraft crash into reactor facilities. The method for developing the database of aircraft accidents to evaluate probability of aircraft crash into reactor facilities is based on the report 'The criteria on assessment of probability of aircraft crash into light water reactor facilities' described above. The 2012 revised database for the latest 20 years from 1992 to 2011 shows the followings. The trend of the 2012 database changes little as compared to the last year's report. (1) The data of commercial aircraft accidents is based on 'Aircraft accident investigation reports of Japan transport safety board' of Ministry of Land, Infrastructure, Transport and Tourism. The number of commercial aircraft accidents is 4 for large fixed-wing aircraft, 58 for small fixed-wing aircraft, 5 for large bladed aircraft and 99 for small bladed aircraft. The relevant accidents

  18. Jet Vertex Charge Reconstruction

    CERN Document Server

    Nektarijevic, Snezana; The ATLAS collaboration

    2015-01-01

    A newly developed algorithm called the jet vertex charge tagger, aimed at identifying the sign of the charge of jets containing $b$-hadrons, referred to as $b$-jets, is presented. In addition to the well established track-based jet charge determination, this algorithm introduces the so-called \\emph{jet vertex charge} reconstruction, which exploits the charge information associated to the displaced vertices within the jet. Furthermore, the charge of a soft muon contained in the jet is taken into account when available. All available information is combined into a multivariate discriminator. The algorithm has been developed on jets matched to generator level $b$-hadrons provided by $t\\bar{t}$ events simulated at $\\sqrt{s}$=13~TeV using the full ATLAS detector simulation and reconstruction.

  19. Acoustical design economic trade off for transport aircraft

    Science.gov (United States)

    Benito, A.

    The effects of ICAO fixed certification limits and local ordinances on acoustic emissions from jets on commercial transport aircraft and costs of operations are explored. The regulations effectively ban some aircraft from operation over populated areas, impose curfews on airports and, in conjunction with local civil aviation rules, levy extra taxes and quotas on noisier equipment. Jet engine manufacturers have attempted to increase the flow laminarity, decrease the exhaust speed and develop acoustic liners for selected duct areas. Retrofits are, however, not usually cost effective due to increased operational costs, e.g., fuel consumption can increase after engine modification because of increased weight. Finally, an attempt is made to assess, monetarily, the costs of noise pollution, wherein fines are levied for noisy aircraft and the money is spent insulating homes from noise.

  20. Monocular Vision System for Fixed Altitude Flight of Unmanned Aerial Vehicles

    Directory of Open Access Journals (Sweden)

    Kuo-Lung Huang

    2015-07-01

    Full Text Available The fastest and most economical method of acquiring terrain images is aerial photography. The use of unmanned aerial vehicles (UAVs has been investigated for this task. However, UAVs present a range of challenges such as flight altitude maintenance. This paper reports a method that combines skyline detection with a stereo vision algorithm to enable the flight altitude of UAVs to be maintained. A monocular camera is mounted on the downside of the aircraft’s nose to collect continuous ground images, and the relative altitude is obtained via a stereo vision algorithm from the velocity of the UAV. Image detection is used to obtain terrain images, and to measure the relative altitude from the ground to the UAV. The UAV flight system can be set to fly at a fixed and relatively low altitude to obtain the same resolution of ground images. A forward-looking camera is mounted on the upside of the aircraft’s nose. In combination with the skyline detection algorithm, this helps the aircraft to maintain a stable flight pattern. Experimental results show that the proposed system enables UAVs to obtain terrain images at constant resolution, and to detect the relative altitude along the flight path.

  1. Supplemental oxygen effect on hypoxemia at moderate altitude in patients with COPD.

    Science.gov (United States)

    Kelly, Paul T; Swanney, Maureen P; Stanton, Josh D; Frampton, Chris; Peters, Matthew J; Beckert, Lutz E

    2009-09-01

    Altitude exposure will cause moderate to severe hypoxemia in patients with chronic obstructive pulmonary disease (COPD). Supplemental oxygen can be used to attenuate this hypoxemia; however, individual response is variable and difficult to predict. The aim of this study was to assess the efficacy of oxygen supplementation in patients with COPD at a barometric pressure similar to that of a commercial aircraft cabin. Following sea-level (40 m) arterial blood gases measurements, 18 patients with COPD were driven to altitude (2086 m), where blood gases were repeated at rest and while on 2 L x min(-1) of supplementary oxygen (altitude O2). Ascent from sea level to altitude caused significant hypoxemia (75 +/- 9 vs. 51 +/- 6 mmHg), which was partially reversed by supplemental oxygen (64 +/- 9 mmHg). Oxygen supplementation did not significantly alter PaCO2 levels (vs. altitude PaCO2). There was a significant relationship between the sea-level CaO2 versus the altitude O2 CaO2 (r = 0.89, P commercial air travel in patients with COPD.

  2. Flowfield Behavior of Supersonic Impinging Jets

    Science.gov (United States)

    Iyer, K. G.; Alvi, F. S.

    1998-11-01

    A detailed study is being conducted which examines the behavior of normally impinging, supersonic jets, issuing from axisymmetric a Mach 1.5 C-D and a sonic nozzle. Our goal is to understand the physics of this flowfield (commonly observed in STOVL aircraft) and its influence on the acoustic and aerodynamic loading on the ground plane and the airframe. The airframe is simulated by a circular disc ('lift' plate) with an annular hole from which the jet is issued. Tests are carried out for a wide range of pressure ratios and the ground plane distance is varied from 1.5 to 60 nozzle diameters. Flowfield measurements include Particle Image Velocimetry (PIV) and schlieren/shadowgraph visualization. Surface measurements on the ground and lift plates include mean and unsteady surface pressure distributions and the surface streamline visualization. Near-field acoustic measurements using a microphone are also obtained. For certain cases, the PIV measurements -- first of their kind, to our knowledge -- clearly show the presence of large-scale coherent turbulent structures which, upon jet impingement, propagate into the resulting wall jet. These structures are believed to generate very high unsteady pressure loads on the ground plane thus leading to ground erosion. They are also suspected to be the source of acoustic waves which lead to a feedback loop causing violent oscillations of the primary jet and can result in increased acoustic loading and subsequent damage to the aircraft. As a result of this detailed study over a wide parametric space, we hope to gain a much better understanding of the physical mechanisms governing this complex flow.

  3. A Study on External Fire Damage of Structures subjected to Aircraft Impact

    International Nuclear Information System (INIS)

    Shin, Sang Shup; Hahm, Daegi; Kim, Min Kyu

    2015-01-01

    A large commercial aircraft consists of various components as fuselage, wings, fuel tank, engine etc. During a collision of the aircraft, the fuel tank with a large amount of jet fuel have a significant effect on the total load of the aircraft as well as causing explosive fire and smoke which affect the safety of the structure and equipment. US Sandia National Laboratories and Finland VTT etc. performed the test and simulation studies to evaluate the dispersion range of the fluid after the crash of liquid filled cylinder missiles. The test condition and results have been referred in this paper. The fluid modeling approach using SPH is applied to evaluate the dispersing range of the fluid, and is compared with the Brown's results. The jet fuel is idealized as particles contained in an aluminum cylinder missile, where those particles can be dispersed to the surrounding area after the missile crashes into a rigid target. The fluid model using the SPH method is briefly verified through comparison with test results, and then the modelling method is applied to a jet fuel model in an aircraft model. The dispersion analysis of jet fuel caused by aircraft impact is performed using an aircraft model for the determination of fire duration and fire affected zone in a nuclear power plant. Finally, the structural integrity of the roof of the structure during a jet fuel fire is evaluated. In this study, the filled jet fuel was modeled by using smooth particle hydrodynamics technique; jet fuel spread area following an aircraft crash was analyzed

  4. A Study on External Fire Damage of Structures subjected to Aircraft Impact

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Sang Shup [Hanyang University, Seoul (Korea, Republic of); Hahm, Daegi; Kim, Min Kyu [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    A large commercial aircraft consists of various components as fuselage, wings, fuel tank, engine etc. During a collision of the aircraft, the fuel tank with a large amount of jet fuel have a significant effect on the total load of the aircraft as well as causing explosive fire and smoke which affect the safety of the structure and equipment. US Sandia National Laboratories and Finland VTT etc. performed the test and simulation studies to evaluate the dispersion range of the fluid after the crash of liquid filled cylinder missiles. The test condition and results have been referred in this paper. The fluid modeling approach using SPH is applied to evaluate the dispersing range of the fluid, and is compared with the Brown's results. The jet fuel is idealized as particles contained in an aluminum cylinder missile, where those particles can be dispersed to the surrounding area after the missile crashes into a rigid target. The fluid model using the SPH method is briefly verified through comparison with test results, and then the modelling method is applied to a jet fuel model in an aircraft model. The dispersion analysis of jet fuel caused by aircraft impact is performed using an aircraft model for the determination of fire duration and fire affected zone in a nuclear power plant. Finally, the structural integrity of the roof of the structure during a jet fuel fire is evaluated. In this study, the filled jet fuel was modeled by using smooth particle hydrodynamics technique; jet fuel spread area following an aircraft crash was analyzed.

  5. Database on aircraft accidents

    International Nuclear Information System (INIS)

    Nishio, Masahide; Koriyama, Tamio

    2012-09-01

    The Reactor Safety Subcommittee in the Nuclear Safety and Preservation Committee published the report 'The criteria on assessment of probability of aircraft crash into light water reactor facilities' as the standard method for evaluating probability of aircraft crash into nuclear reactor facilities in July 2002. In response to the report, Japan Nuclear Energy Safety Organization has been collecting open information on aircraft accidents of commercial airplanes, self-defense force (SDF) airplanes and US force airplanes every year since 2003, sorting out them and developing the database of aircraft accidents for latest 20 years to evaluate probability of aircraft crash into nuclear reactor facilities. This year, the database was revised by adding aircraft accidents in 2010 to the existing database and deleting aircraft accidents in 1991 from it, resulting in development of the revised 2011 database for latest 20 years from 1991 to 2010. Furthermore, the flight information on commercial aircrafts was also collected to develop the flight database for latest 20 years from 1991 to 2010 to evaluate probability of aircraft crash into reactor facilities. The method for developing the database of aircraft accidents to evaluate probability of aircraft crash into reactor facilities is based on the report 'The criteria on assessment of probability of aircraft crash into light water reactor facilities' described above. The 2011 revised database for latest 20 years from 1991 to 2010 shows the followings. The trend of the 2011 database changes little as compared to the last year's one. (1) The data of commercial aircraft accidents is based on 'Aircraft accident investigation reports of Japan transport safety board' of Ministry of Land, Infrastructure, Transport and Tourism. 4 large fixed-wing aircraft accidents, 58 small fixed-wing aircraft accidents, 5 large bladed aircraft accidents and 114 small bladed aircraft accidents occurred. The relevant accidents for evaluating

  6. Delving into QCD jets

    International Nuclear Information System (INIS)

    Konishi, K.

    1980-01-01

    The author discusses, in an introductory fashion, the latest developments in the study of hadronic jets produced in hard processes, based on perturbative QCD. Emphasis is on jet calculus (and its applications and generalizations), and on the appearance of a parton-like consistent, over-all picture of jet evolution in momentum, colour, and real space-time. (Auth.)

  7. Investigation of PVdF active diaphragms for synthetic jets

    Science.gov (United States)

    Bailo, Kelly C.; Brei, Diann E.; Calkins, Frederick T.

    2000-06-01

    Current research has shown that aircraft can gain significant aerodynamic performance benefits by employing active flow control (AFC). One of the enabling technologies of AFC is the synthetic jet. Synthetic jets, also known as zero-net-mass flux actuators, act as bi-directional pumps injecting high momentum air into the local aerodynamic flow. Previous work has concentrated on high frequency synthetic jets based on piezoelectric active diaphragms such as Thunder actuators. Low frequency synthetic jets present a unique challenge requiring large displacements, which current technology has difficulty meeting. Boeing is investigating novel shaped low frequency synthetic jets that can modify the flow over fixed aircraft wings. This paper present the initial study of two promising active diaphragm concepts: a crescent shape and an opposing bender shape. These active diaphragms were numerically modeled utilizing the general-purpose finite element code ABAQUS. Using the ABAQUS results, the dynamic volume change within each jet was calculated and incorporated into an analytical linear Bernoulli model to predict the velocities and pressures at the nozzle. Simulations were performed to determine trends to assist in selection of prototype configurations. Prototypes of both diaphragm concepts were constructed from polyvinylidene fluoride and experimentally tested at Boeing with promising results.

  8. Air-sampling inlet contamination by aircraft emissions on the NASA CV-990 aircraft

    Science.gov (United States)

    Condon, E. P.; Vedder, J. F.

    1984-01-01

    Results of an experimental investigation of the contamination of air sampling inlets by aircraft emissions from the NASA CV-990 research aircraft are presented. This four-engine jet aircraft is a NASA facility used for many different atmospheric and meteorological experiments, as well as for developing spacecraft instrumentation for remote measurements. Our investigations were performed to provide information on which to base the selection of sampling locations for a series of multi-instrument missions for measuring tropospheric trace gases. The major source of contamination is the exhaust from the jet engines, which generate many of the same gases that are of interest in atmospheric chemistry, as well as other gases that may interfere with sampling measurements. The engine exhaust contains these gases in mixing ratios many orders of magnitude greater than those that occur in the clean atmosphere which the missions seek to quantify. Pressurized samples of air were collected simultaneously from a scoop located forward of the engines to represent clean air and from other multiport scoops at various aft positions on the aircraft. The air samples were analyzed in the laboratory by gas chromatography for carbon monoxide, an abundant combustion by-product. Data are presented for various scoop locations under various flight conditions.

  9. Liquid water content variation with altitude in clouds over Europe

    Science.gov (United States)

    Andreea, Boscornea; Sabina, Stefan

    2013-04-01

    Cloud water content is one of the most fundamental measurements in cloud physics. Knowledge of the vertical variability of cloud microphysical characteristics is important for a variety of reasons. The profile of liquid water content (LWC) partially governs the radiative transfer for cloudy atmospheres, LWC profiles improves our understanding of processes acting to form and maintain cloud systems and may lead to improvements in the representation of clouds in numerical models. Presently, in situ airborne measurements provide the most accurate information about cloud microphysical characteristics. This information can be used for verification of both numerical models and cloud remote sensing techniques. The aim of this paper was to analyze the liquid water content (LWC) measurements in clouds, in time of the aircraft flights. The aircraft and its platform ATMOSLAB - Airborne Laboratory for Environmental Atmospheric Research is property of the National Institute for Aerospace Research "Elie Carafoli" (INCAS), Bucharest, Romania. The airborne laboratory equipped for special research missions is based on a Hawker Beechcraft - King Air C90 GTx aircraft and is equipped with a sensors system CAPS - Cloud, Aerosol and Precipitation Spectrometer (30 bins, 0.51-50 m). The processed and analyzed measurements are acquired during 4 flights from Romania (Bucharest, 44°25'57″N 26°06'14″E) to Germany (Berlin 52°30'2″N 13°23'56″E) above the same region of Europe. The flight path was starting from Bucharest to the western part of Romania above Hungary, Austria at a cruse altitude between 6000-8500 m, and after 5 hours reaching Berlin. In total we acquired data during approximately 20 flight hours and we presented the vertical and horizontal LWC variations for different cloud types. The LWC values are similar for each type of cloud to values from literature. The vertical LWC profiles in the atmosphere measured during takeoff and landing of the aircraft have shown their

  10. Altitude Stress During Participation of Medical Congress

    Science.gov (United States)

    Kim, Soon Bae; Kim, Jong Sung; Kim, Sang Jun; Cho, Su Hee

    2016-01-01

    Medical congresses often held in highlands. We reviewed several medical issues associated with altitude stress especially while physicians have participated medical congress held in high altitude. Altitude stress, also known as an acute mountain sickness (AMS), is caused by acute exposure to low oxygen level at high altitude which is defined as elevations at or above 1,200 m and AMS commonly occurs above 2,500 m. Altitude stress with various symptoms including insomnia can also be experienced in airplane. AMS and drunken state share many common features in symptoms, neurologic manifestations and even show multiple microbleeds in corpus callosum and white matter on MRI. Children are more susceptible to altitude stress than adults. Gradual ascent is the best method for the prevention of altitude stress. Adequate nutrition (mainly carbohydrates) and hydration are recommended. Consumption of alcohol can exacerbate the altitude-induced impairments in judgment and the visual senses and promote psychomotor dysfunction. For prevention or treatment of altitude stress, acetazolamide, phosphodiesterase inhibitors, dexamethasone and erythropoietin are helpful. Altitude stress can be experienced relatively often during participation of medical congress. It is necessary to remind the harmful effect of AMS because it can cause serious permanent organ damage even though the symptoms are negligible in most cases. PMID:27621942

  11. Editorial on Future Jet Technologies

    Science.gov (United States)

    Gal-Or, Benjamin

    2014-12-01

    The jet engine is the prime flight controller in post-stall flight domains where conventional flight control fails, or when the engine prevents catastrophes in training, combat, loss of all airframe hydraulics (the engine retains its own hydraulics), loss of one engine, pilot errors, icing on the wings, landing gear and runway issues in takeoff and landing and in bad-whether recoveries. The scientific term for this revolutionary technology is "jet-steering", and in engineering practice - "thrust vectoring", or "TV". Jet-Steering in advanced fighter aircraft designs is integrated with stealth technology. The resulting classified Thrust-Vectoring-Stealth ("TVS") technology has generated a second jet-revolution by which all Air-&-Sea-Propulsion Science and R&D are now being reassessed. Classified F-22, X-47B/C and RQ-180 TVS-vehicles stand at the front of this revolution. But recent transfers of such sensitive technologies to South Korea and Japan [1-5], have raised various fundamental issues that are evaluated by this editorial-review. One, and perhaps a key conclusion presented here, means that both South Korea and Japan may have missed one of their air-&-sea defenses: To develop and field low-cost unmanned fleets of jet-drones, some for use with expensive, TVS-fighter aircraft in highly congested areas. In turn, the U.S., EU, Russia and China, are currently developing such fleets at various TVS levels and sizes. China, for instance, operates at least 15,000 drones ("UAVs") by 2014 in the civilian sector alone. All Chinese drones have been developed by at least 230 developers/manufacturers [1-16]. Mobile telecommunication of safe links between flyers and combat drones ("UCAVs") at increasingly deep penetrations into remote, congested areas, can gradually be purchased-developed-deployed and then operated by extant cader of tens of thousands "National Champion Flyers" who have already mastered the operation of mini-drones in free-to-all sport clubs under national

  12. Performance Comparison of Sweeping/Steady Jet Actuators

    Science.gov (United States)

    Hirsch, Damian; Mercier, Justin; Noca, Flavio; Gharib, Morteza

    2015-11-01

    Flow control through the use of steady jet actuators has been used on various aircraft models since the late 1950's. However, the focus of recent studies has shifted towards the use of sweeping jets (fluidic oscillators) rather than steady jet actuators. In this work, experiments using various jet actuator designs were conducted at GALCIT's Lucas Wind Tunnel on a NACA 0012 vertical tail model similar to that of the Boeing 767 vertical stabilizer at Reynolds numbers ranging from 0.5 to 1.2 million. The rudder angle was fixed at 20 degrees. A total of 32 jet actuators were installed along the wingspan perpendicular to the trailing edge and the rudder shoulder of the vertical stabilizer. It is known that these types of flow control prevent separation. However, the goal of this work is to compare different jet designs and evaluate their performance. Parameters such as the number of actuators, their volumetric flow, and the wind tunnel speed were varied. The lift generation capabilities of steady and sweeping jet actuators were then compared. Another set of experiments was conducted to compare a new sweeping jet actuator design with one of the standard versions. Supported by Boeing.

  13. Low-resolution ship detection from high-altitude aerial images

    Science.gov (United States)

    Qi, Shengxiang; Wu, Jianmin; Zhou, Qing; Kang, Minyang

    2018-02-01

    Ship detection from optical images taken by high-altitude aircrafts such as unmanned long-endurance airships and unmanned aerial vehicles has broad applications in marine fishery management, ship monitoring and vessel salvage. However, the major challenge is the limited capability of information processing on unmanned high-altitude platforms. Furthermore, in order to guarantee the wide detection range, unmanned aircrafts generally cruise at high altitudes, resulting in imagery with low-resolution targets and strong clutters suffered by heavy clouds. In this paper, we propose a low-resolution ship detection method to extract ships from these high-altitude optical images. Inspired by a recent research on visual saliency detection indicating that small salient signals could be well detected by a gradient enhancement operation combined with Gaussian smoothing, we propose the facet kernel filtering to rapidly suppress cluttered backgrounds and delineate candidate target regions from the sea surface. Then, the principal component analysis (PCA) is used to compute the orientation of the target axis, followed by a simplified histogram of oriented gradient (HOG) descriptor to characterize the ship shape property. Finally, support vector machine (SVM) is applied to discriminate real targets and false alarms. Experimental results show that the proposed method actually has high efficiency in low-resolution ship detection.

  14. JET Joint Undertaking

    International Nuclear Information System (INIS)

    Keen, B.E.; Lallia, P.; O'Hara, G.W.; Pollard, I.E.

    1987-06-01

    The paper presents the annual report of the Joint European Torus (JET) Joint Undertaking, 1986. The report is divided into two parts: a part on the scientific and technical programme of the project, and a part setting out the administration and organisation of the Project. The first part includes: a summary of the main features of the JET apparatus, the JET experimental programme, the position of the Project in the overall Euratom programme, and how JET relates to other large fusion devices throughout the world. In addition, the technical status of JET is described, as well as the results of the JET operations in 1986. The final section of the first part outlines the proposed future programme of JET. (U.K.)

  15. Jet substructure in ATLAS

    CERN Document Server

    Miller, David W

    2011-01-01

    Measurements are presented of the jet invariant mass and substructure in proton-proton collisions at $\\sqrt{s} = 7$ TeV with the ATLAS detector using an integrated luminosity of 37 pb$^{-1}$. These results exercise the tools for distinguishing the signatures of new boosted massive particles in the hadronic final state. Two "fat" jet algorithms are used, along with the filtering jet grooming technique that was pioneered in ATLAS. New jet substructure observables are compared for the first time to data at the LHC. Finally, a sample of candidate boosted top quark events collected in the 2010 data is analyzed in detail for the jet substructure properties of hadronic "top-jets" in the final state. These measurements demonstrate not only our excellent understanding of QCD in a new energy regime but open the path to using complex jet substructure observables in the search for new physics.

  16. Investigating the auroral electrojets with low altitude polar orbiting satellites

    DEFF Research Database (Denmark)

    Moretto, T.; Olsen, Nils; Ritter, P.

    2002-01-01

    Three geomagnetic satellite missions currently provide high precision magnetic field measurements from low altitude polar orbiting spacecraft. We demonstrate how these data can be used to determine the intensity and location of the horizontal currents that flow in the ionosphere, predominantly...... to another event for which the combined measurements of the three satellites provide a comprehensive view of the current systems. The analysis hereof reveals some surprising results concerning the connection between solar wind driver and the resulting ionospheric currents. Specifically, preconditioning.......8-0.9) is observed between the amplitudes of the derived currents and the commonly used auroral electro-jet indices based on magnetic measurements at ground. This points to the potential of defining an auroral activity index based on the satellite observations, which could be useful for space weather monitoring...

  17. Aircraft accident analysis for emergency planning and safety analysis

    International Nuclear Information System (INIS)

    Nicolosi, S.L.; Jordan, H.; Foti, D.; Mancuso, J.

    1996-01-01

    Potential aircraft accidents involving facilities at the Rocky Flats Environmental Technology Site (Site) are evaluated to assess their safety significance. This study addresses the probability and facility penetrability of aircraft accidents at the Site. The types of aircraft (large, small, etc.) that may credibly impact the Site determine the types of facilities that may be breached. The methodology used in this analysis follows elements of the draft Department of Energy Standard ''Accident Analysis for Aircraft Crash into Hazardous Facilities'' (July 1995). Key elements used are: the four-factor frequency equation for aircraft accidents; the distance criteria for consideration of airports, airways, and jet routes; the consideration of different types of aircraft; and the Modified National Defense Research Committee (NDRC) formula for projectile penetration, perforation, and minimum resistant thickness. The potential aircraft accident frequency for each type of aircraft applicable to the Site is estimated using a four-factor formula described in the draft Standard. The accident frequency is the product of the annual number of operations, probability of an accident, probability density function, and area. The annual number of operations is developed from site-specific and state-wide data

  18. Comprehensive analysis of transport aircraft flight performance

    Science.gov (United States)

    Filippone, Antonio

    2008-04-01

    This paper reviews the state-of-the art in comprehensive performance codes for fixed-wing aircraft. The importance of system analysis in flight performance is discussed. The paper highlights the role of aerodynamics, propulsion, flight mechanics, aeroacoustics, flight operation, numerical optimisation, stochastic methods and numerical analysis. The latter discipline is used to investigate the sensitivities of the sub-systems to uncertainties in critical state parameters or functional parameters. The paper discusses critically the data used for performance analysis, and the areas where progress is required. Comprehensive analysis codes can be used for mission fuel planning, envelope exploration, competition analysis, a wide variety of environmental studies, marketing analysis, aircraft certification and conceptual aircraft design. A comprehensive program that uses the multi-disciplinary approach for transport aircraft is presented. The model includes a geometry deck, a separate engine input deck with the main parameters, a database of engine performance from an independent simulation, and an operational deck. The comprehensive code has modules for deriving the geometry from bitmap files, an aerodynamics model for all flight conditions, a flight mechanics model for flight envelopes and mission analysis, an aircraft noise model and engine emissions. The model is validated at different levels. Validation of the aerodynamic model is done against the scale models DLR-F4 and F6. A general model analysis and flight envelope exploration are shown for the Boeing B-777-300 with GE-90 turbofan engines with intermediate passenger capacity (394 passengers in 2 classes). Validation of the flight model is done by sensitivity analysis on the wetted area (or profile drag), on the specific air range, the brake-release gross weight and the aircraft noise. A variety of results is shown, including specific air range charts, take-off weight-altitude charts, payload-range performance

  19. Variation in aerodynamic coefficients with altitude

    Directory of Open Access Journals (Sweden)

    Faiza Shahid

    Full Text Available Precise aerodynamics performance prediction plays key role for a flying vehicle to get its mission completed within desired accuracy. Aerodynamic coefficients for same Mach number can be different at different altitude due to difference in Reynolds number. Prediction of these aerodynamics coefficients can be made through experiments, analytical solution or Computational Fluid Dynamics (CFD. Advancements in computational power have generated the concept of using CFD as a virtual Wind Tunnel (WT, hence aerodynamic performance prediction in present study is based upon CFD (numerical test rig. Simulations at different altitudes for a range of Mach numbers with zero angle of attack are performed to predict axial force coefficient behavior with altitude (Reynolds number. Similar simulations for a fixed Mach number ‘3’ and a range of angle of attacks are also carried out to envisage the variation in normal force and pitching moment coefficients with altitude (Reynolds number. Results clearly depict that the axial force coefficient is a function of altitude (Reynolds number and increase as altitude increases, especially for subsonic region. Variation in axial force coefficient with altitude (Reynolds number slightly increases for larger values of angle of attacks. Normal force and pitching moment coefficients do not depend on altitude (Reynolds number at smaller values of angle of attacks but show slight decrease as altitude increases. Present study suggests that variation of normal force and pitching moment coefficients with altitude can be neglected but the variation of axial force coefficient with altitude should be considered for vehicle fly in dense atmosphere. It is recommended to continue this study to more complex configurations for various Mach numbers with side slip and real gas effects. Keywords: Mach number, Reynolds number, Blunt body, Altitude effect, Angle of attacks

  20. Helicopter Acoustic Flight Test with Altitude Variation and Maneuvers

    Science.gov (United States)

    Watts, Michael E.; Greenwood, Eric; Sim, Ben; Stephenson, James; Smith, Charles D.

    2016-01-01

    A cooperative flight test campaign between NASA and the U.S. Army was performed from September 2014 to February 2015. The purposes of the testing were to: investigate the effects of altitude variation on noise generation, investigate the effects of gross weight variation on noise generation, establish the statistical variability in acoustic flight testing of helicopters, and characterize the effects of transient maneuvers on radiated noise for a medium-lift utility helicopter. This test was performed at three test sites (0, 4000, and 7000 feet above mean sea level) with two aircraft (AS350 SD1 and EH-60L) tested at each site. This report provides an overview of the test, documents the data acquired and describes the formats of the stored data.

  1. High-Altitude Platforms - Present Situation and Technology Trends

    Directory of Open Access Journals (Sweden)

    Flavio Araripe D'Oliveira

    2016-07-01

    Full Text Available High-altitude platforms (HAPs are aircraft, usually unmanned airships or airplanes positioned above 20 km, in the stratosphere, in order to compose a telecommunications network or perform remote sensing. In the 1990 and 2000 decades, several projects were launched, but very few had continued. In 2014, 2 major Internet companies (Google and Facebook announced investments in new HAP projects to provide Internet access in regions without communication infrastructure (terrestrial or satellite, bringing back attention to the development of HAP. This article aims to survey the history of HAPs, the current state-of-the-art (April 2016, technology trends and challenges. The main focus of this review will be on technologies directly related to the aerial platform, inserted in the aeronautical engineering field of knowledge, not detailing aspects of the telecommunications area.

  2. Investigating potential correlations between jet engine noise and plume dynamics in the hypertemporal infrared domain

    Science.gov (United States)

    Cunio, Phillip M.; Weber, Reed; Knobel, Kimberly; Wager, Jason; Lopez, Gerardo

    2014-09-01

    Jet engine noise can be a hazard and environmental pollutant, affecting personnel working in close proximity to jet engines. Mitigating the effects of jet engine noise could reduce the potential for hearing loss in runway workers, but engine noise is not yet sufficiently well-characterized that it can easily be mitigated for new engine designs. That is, there exists a very complex relationship between jet engine design parameters, operating conditions, and resultant noise power levels. In this paper, we propose to evaluate the utility of high-speed imaging (also called hypertemporal imaging) in correlating the infrared signatures of jet aircraft engines with acoustic noise from the jet engines. This paper will focus on a theoretical analysis of jet engine infrared signatures, and will define potentially-detectable characteristics of such signatures in the hypertemporal domain. A systematic test campaign to determine whether such signatures actually exist and can be correlated with acoustic jet engine characteristics will be proposed. The detection of any hypertemporal signatures in association with acoustic signatures of jet engines will enable the use of a new domain in characterizing jet engine noise. This may in turn enable new methods of predicting or mitigating jet engine noise, which could lead to benefits for operators of large numbers of jet engines.

  3. Cardiovascular Effects of Altitude on Performance Athletes.

    Science.gov (United States)

    Shah, Ankit B; Coplan, Neil

    Altitude plays an important role in cardiovascular performance and training for athletes. Whether it is mountaineers, skiers, or sea-level athletes trying to gain an edge by training or living at increased altitude, there are many potential benefits and harms of such endeavors. Echocardiographic studies done on athletes at increased altitude have shown evidence for right ventricular dysfunction and pulmonary hypertension, but no change in left ventricular ejection fraction. In addition, 10% of athletes are susceptible to pulmonary hypertension and high-altitude pulmonary edema. Some studies suggest that echocardiography may be able to identify athletes susceptible to high-altitude pulmonary edema prior to competing or training at increased altitudes. Further research is needed on the long-term effects of altitude training, as repeated, transient episodes of pulmonary hypertension and right ventricular dysfunction may have long-term implications. Current literature suggests that performance athletes are not at higher risk for ventricular arrhythmias when training or competing at increased altitudes. For sea-level athletes, the optimal strategy for attaining the benefits while minimizing the harms of altitude training still needs to be clarified, although-for now-the "live high, train low" approach appears to have the most rationale.

  4. Turbulent buoyant jets and plumes

    CERN Document Server

    Rodi, Wolfgang

    The Science & Applications of Heat and Mass Transfer: Reports, Reviews, & Computer Programs, Volume 6: Turbulent Buoyant Jets and Plumes focuses on the formation, properties, characteristics, and reactions of turbulent jets and plumes. The selection first offers information on the mechanics of turbulent buoyant jets and plumes and turbulent buoyant jets in shallow fluid layers. Discussions focus on submerged buoyant jets into shallow fluid, horizontal surface or interface jets into shallow layers, fundamental considerations, and turbulent buoyant jets (forced plumes). The manuscript then exami

  5. High Velocity Jet Noise Source Location and Reduction. Task 4. Development/Evaluation of Techniques for ’Inflight’ Investigation.

    Science.gov (United States)

    1977-02-22

    included. Acoustic results from the Learjet and NASA-Lewis F-106 Aircraft Flyovers and the French Aerotrain Tests, taken with a baseline, 8-lobe, and 104...between aerotrain data and transformed free jet data are presented for three primary jet velocities and two flight velocities for the three nozzle types.

  6. Small transport aircraft technology

    Science.gov (United States)

    Williams, L. J.

    1983-01-01

    Information on commuter airline trends and aircraft developments is provided to upgrade the preliminary findings of a NASA-formed small transport aircraft technology (STAT) team, established to determine whether the agency's research and development programs could help commuter aircraft manufacturers solve technical problems related to passenger acceptance and use of 19- to 50-passenger aircraft. The results and conclusions of the full set of completed STAT studies are presented. These studies were performed by five airplane manufacturers, five engine manufacturers, and two propeller manufacturers. Those portions of NASA's overall aeronautics research and development programs which are applicable to commuter aircraft design are summarized. Areas of technology that might beneficially be expanded or initiated to aid the US commuter aircraft manufacturers in the evolution of improved aircraft for the market are suggested.

  7. Ultraviolet spectrophotometer for measuring columnar atmospheric ozone from aircraft

    Science.gov (United States)

    Hanser, F. A.; Sellers, B.; Briehl, D. C.

    1978-01-01

    An ultraviolet spectrophotometer (UVS) to measure downward solar fluxes from an aircraft or other high altitude platform is described. The UVS uses an ultraviolet diffuser to obtain large angular response with no aiming requirement, a twelve-position filter wheel with narrow (2-nm) and broad (20-nm) bandpass filters, and an ultraviolet photodiode. The columnar atmospheric ozone above the UVS (aircraft) is calculated from the ratios of the measured ultraviolet fluxes. Comparison with some Dobson station measurements gives agreement to 2%. Some UVS measured ozone profiles over the Pacific Ocean for November 1976 are shown to illustrate the instrument's performance.

  8. On jet substructure methods for signal jets

    Energy Technology Data Exchange (ETDEWEB)

    Dasgupta, Mrinal [Consortium for Fundamental Physics, School of Physics & Astronomy, University of Manchester,Oxford Road, Manchester M13 9PL (United Kingdom); Powling, Alexander [School of Physics & Astronomy, University of Manchester,Oxford Road, Manchester M13 9PL (United Kingdom); Siodmok, Andrzej [Institute of Nuclear Physics, Polish Academy of Sciences,ul. Radzikowskiego 152, 31-342 Kraków (Poland); CERN, PH-TH,CH-1211 Geneva 23 (Switzerland)

    2015-08-17

    We carry out simple analytical calculations and Monte Carlo studies to better understand the impact of QCD radiation on some well-known jet substructure methods for jets arising from the decay of boosted Higgs bosons. Understanding differences between taggers for these signal jets assumes particular significance in situations where they perform similarly on QCD background jets. As an explicit example of this we compare the Y-splitter method to the more recently proposed Y-pruning technique. We demonstrate how the insight we gain can be used to significantly improve the performance of Y-splitter by combining it with trimming and show that this combination outperforms the other taggers studied here, at high p{sub T}. We also make analytical estimates for optimal parameter values, for a range of methods and compare to results from Monte Carlo studies.

  9. Jet Substructure Without Trees

    Energy Technology Data Exchange (ETDEWEB)

    Jankowiak, Martin; Larkoski, Andrew J.; /SLAC /Stanford U., ITP

    2011-08-19

    We present an alternative approach to identifying and characterizing jet substructure. An angular correlation function is introduced that can be used to extract angular and mass scales within a jet without reference to a clustering algorithm. This procedure gives rise to a number of useful jet observables. As an application, we construct a top quark tagging algorithm that is competitive with existing methods. In preparation for the LHC, the past several years have seen extensive work on various aspects of collider searches. With the excellent resolution of the ATLAS and CMS detectors as a catalyst, one area that has undergone significant development is jet substructure physics. The use of jet substructure techniques, which probe the fine-grained details of how energy is distributed in jets, has two broad goals. First, measuring more than just the bulk properties of jets allows for additional probes of QCD. For example, jet substructure measurements can be compared against precision perturbative QCD calculations or used to tune Monte Carlo event generators. Second, jet substructure allows for additional handles in event discrimination. These handles could play an important role at the LHC in discriminating between signal and background events in a wide variety of particle searches. For example, Monte Carlo studies indicate that jet substructure techniques allow for efficient reconstruction of boosted heavy objects such as the W{sup {+-}} and Z{sup 0} gauge bosons, the top quark, and the Higgs boson.

  10. Jet quenching at ALICE

    International Nuclear Information System (INIS)

    Bianchi, Nicola

    2007-01-01

    RHIC results on leading hadron suppression indicate that the jets produced in hard processes are strongly quenched by the dense medium created in heavy ion collisions. Most of the energy lost by the leading parton remains within the jet cone, but several questions on the medium modification of the jet structure have not been addressed. These include the longitudinal and transverse structures of the quenched jet, the associated radiation observables, and the dependence on the parton flavor. These topics will be studied by ALICE thanks to both the robustness of its tracking and the charged particle identification system. Large medium effects are expected in both the low pt and in the high pt regions. To make ALICE better suited for jet physics, the performances on high p t particles and jets can be significantly improved by completing the present set-up with a large Electromagnetic Calorimeter (EmCal). This will significantly improve the resolution on the jet energy and on the particle composition (with the detection of both charged and neutral particles). It will also allow to calibrate the jet energy by measuring the high energy photon emitted in the opposite direction. EmCal will be used to trigger on the jet energy itself, thus allowing a significant improvement of the statistics achievable for jets of high energy. Finally, due too both the γ/π 0 and the electron/hadron discrimination, EmCal will enhance the ALICE capabilities at high p t for direct photons and heavy quarks measurements

  11. Compatibility of elastomers in alternate jet fuels

    Science.gov (United States)

    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.

  12. Physiological aspects of altitude training and the use of altitude simulators

    OpenAIRE

    Ranković Goran; Radovanović Dragan

    2005-01-01

    Altitude training in various forms is widely practiced by athletes and coaches in an attempt to improve sea level endurance. Training at high altitude may improve performance at sea level through altitude acclimatization, which improves oxygen transport and/or utilization, or through hypoxia, which intensifies the training stimulus. This basic physiological aspect allows three training modalities: live high and train high (classic high-altitude training), live low and train high (training thr...

  13. Fundamentals of aircraft and rocket propulsion

    CERN Document Server

    El-Sayed, Ahmed F

    2016-01-01

    This book provides a comprehensive basics-to-advanced course in an aero-thermal science vital to the design of engines for either type of craft. The text classifies engines powering aircraft and single/multi-stage rockets, and derives performance parameters for both from basic aerodynamics and thermodynamics laws. Each type of engine is analyzed for optimum performance goals, and mission-appropriate engines selection is explained. Fundamentals of Aircraft and Rocket Propulsion provides information about and analyses of: thermodynamic cycles of shaft engines (piston, turboprop, turboshaft and propfan); jet engines (pulsejet, pulse detonation engine, ramjet, scramjet, turbojet and turbofan); chemical and non-chemical rocket engines; conceptual design of modular rocket engines (combustor, nozzle and turbopumps); and conceptual design of different modules of aero-engines in their design and off-design state. Aimed at graduate and final-year undergraduate students, this textbook provides a thorough grounding in th...

  14. Variation in aerodynamic coefficients with altitude

    Science.gov (United States)

    Shahid, Faiza; Hussain, Mukkarum; Baig, Mirza Mehmood; Haq, Ihtram ul

    Precise aerodynamics performance prediction plays key role for a flying vehicle to get its mission completed within desired accuracy. Aerodynamic coefficients for same Mach number can be different at different altitude due to difference in Reynolds number. Prediction of these aerodynamics coefficients can be made through experiments, analytical solution or Computational Fluid Dynamics (CFD). Advancements in computational power have generated the concept of using CFD as a virtual Wind Tunnel (WT), hence aerodynamic performance prediction in present study is based upon CFD (numerical test rig). Simulations at different altitudes for a range of Mach numbers with zero angle of attack are performed to predict axial force coefficient behavior with altitude (Reynolds number). Similar simulations for a fixed Mach number '3' and a range of angle of attacks are also carried out to envisage the variation in normal force and pitching moment coefficients with altitude (Reynolds number). Results clearly depict that the axial force coefficient is a function of altitude (Reynolds number) and increase as altitude increases, especially for subsonic region. Variation in axial force coefficient with altitude (Reynolds number) slightly increases for larger values of angle of attacks. Normal force and pitching moment coefficients do not depend on altitude (Reynolds number) at smaller values of angle of attacks but show slight decrease as altitude increases. Present study suggests that variation of normal force and pitching moment coefficients with altitude can be neglected but the variation of axial force coefficient with altitude should be considered for vehicle fly in dense atmosphere. It is recommended to continue this study to more complex configurations for various Mach numbers with side slip and real gas effects.

  15. Aircraft Carrier Exposure Testing of Aircraft Materials

    National Research Council Canada - National Science Library

    Lee, Eui

    2004-01-01

    .... Test and control specimens were affixed on exposure racks and installed on aircraft carriers to compare adhesive bonding primers for aluminum and to determine the static property behavior of various...

  16. Jets in Planetary Atmospheres

    Science.gov (United States)

    Dowling, Tim

    2018-05-01

    Jet streams, "jets" for short, are remarkably coherent streams of air found in every major atmosphere. They have a profound effect on a planet's global circulation, and have been an enigma since the belts and zones of Jupiter were discovered in the 1600s. The study of jets, including what processes affect their size, strength, direction, shear stability, and predictability, are active areas of research in geophysical fluid dynamics. Jet research is multidisciplinary and global, involving collaborations between observers, experimentalists, numerical modelers, and applied mathematicians. Jets in atmospheres have strong analogies with shear instability in nonneutral plasmas, and these connections are highlighted throughout the article. The article begins with a description of four major challenges that jet researchers face: nonlinearity, non-intuitive wave physics, non-constant-coefficients, and copious nondimensional numbers. Then, two general fluid-dynamical tenets, the practice of rendering expressions dimensionally homogeneous (nondimensional), and the universal properties of shocks are applied to the open question of what controls the on-off switch of shear instability. The discussion progresses to how the physics of jets varies in equatorial, midlatitude, and polar regions, and how jets are observed to behave in each of these settings. The all-in-one conservation law of potential vorticity (PV), which combines the conservation laws of mass, momentum, and thermal energy into a single expression, is the common language of jet research. Earth and Uranus have weak retrograde equatorial jets, but most planets exhibit super-rotating equatorial jets, which require eddies to transport momentum up gradient in a non-intuitive manner. Jupiter and Saturn exhibit multiple alternating jets in their midlatitudes. The theory for why jets are invariably zonal (east-west orientated) is reviewed, and the particular challenges that Jupiter's sharp westward jets present to existing

  17. Aircraft and background noise annoyance effects

    Science.gov (United States)

    Willshire, K. F.

    1984-01-01

    To investigate annoyance of multiple noise sources, two experiments were conducted. The first experiment, which used 48 subjects, was designed to establish annoyance-noise level functions for three community noise sources presented individually: jet aircraft flyovers, air conditioner, and traffic. The second experiment, which used 216 subjects, investigated the effects of background noise on aircraft annoyance as a function of noise level and spectrum shape; and the differences between overall, aircraft, and background noise annoyance. In both experiments, rated annoyance was the dependent measure. Results indicate that the slope of the linear relationship between annoyance and noise level for traffic is significantly different from that of flyover and air conditioner noise and that further research was justified to determine the influence of the two background noises on overall, aircraft, and background noise annoyance (e.g., experiment two). In experiment two, total noise exposure, signal-to-noise ratio, and background source type were found to have effects on all three types of annoyance. Thus, both signal-to-noise ratio, and the background source must be considered when trying to determine community response to combined noise sources.

  18. Phenomenology of jets

    International Nuclear Information System (INIS)

    Walsh, T.F.

    1980-05-01

    The basic idea of these lectures is very simple. Quarks and gluons - the elementary quanta of quantum chromodynamics or QCD - are produced with perturbarively calculable rates in short distance processes. This is because of asymptotic freedom. These quanta produced at short distances are, in a sense, 'visible' as jets of hadrons. (The jets do not contain the colored QCD quanta if - as we will assume - color is confined. The jets contain only colorless hadrons.) The distribution of these jets is the distribution of the original quanta, apart from fluctuations generated in the (long distance) jet formation process. The distribution of the jets can thus thest QCD in a particularly clear way at the parton level, at distance of order 5 x 10 -16 cm (PETRA/PEP energies). (orig.)

  19. A turbulent radio jet

    International Nuclear Information System (INIS)

    Kahn, F.D.

    1983-01-01

    A relativistic plasma flow can explain many of the observations on the one-sided jets, which are associated with radio sources that show superluminal motions in their cores. The pressure from the ambient medium will communicate across the jet in a relatively short distance, typically 30 kpc. The friction between the jet and the external medium then makes the flow go turbulent. As a result the jet dissipates energy and will be brought to rest within a few hundred kpc, if it does not strike an obstacle before. The mean flow in the jet is strongly sheared and stretches the lines of force of any magnetic field frozen into the plasma. The dominant field direction, as seen from the rest frame of the plasma, is therefore parallel to the length of the jet. Polarization measurements have shown that this is in fact the case. (author)

  20. Flight simulation program for high altitude long endurance unmanned vehicle; Kokodo mujinki no hiko simulation program

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, H.; Hashidate, M. [National Aerospace Laboratory, Tokyo (Japan)

    1995-11-01

    An altitude of about 20 km has the atmospheric density too dilute for common aircraft, and the air resistance too great for satellites. Attention has been drawn in recent years on a high-altitude long-endurance unmanned vehicle that flies at this altitude for a long period of time to serve as a wave relaying base and perform traffic control. Therefore, a development was made on a flight simulation program to evaluate and discuss the guidance and control laws for the high-altitude unmanned vehicle. Equations of motion were derived for three-dimensional six freedom and three-dimensional three freedom. Aerodynamic characteristics of an unmanned vehicle having a Rectenna wing were estimated, and formulation was made according to the past research results on data of winds that the unmanned vehicle is anticipated to encounter at an altitude of 20 km. Noticing the inside of a horizontal plane, a proposal was given on a guidance law that follows a given path. A flight simulation was carried out to have attained a prospect that the unmanned vehicle may be enclosed in a limited space even if the vehicle is encountered with a relatively strong wind. 18 refs., 20 figs., 1 tab.

  1. Solar Cell Short Circuit Current Errors and Uncertainties During High Altitude Calibrations

    Science.gov (United States)

    Snyder, David D.

    2012-01-01

    High altitude balloon based facilities can make solar cell calibration measurements above 99.5% of the atmosphere to use for adjusting laboratory solar simulators. While close to on-orbit illumination, the small attenuation to the spectra may result in under measurements of solar cell parameters. Variations of stratospheric weather, may produce flight-to-flight measurement variations. To support the NSCAP effort, this work quantifies some of the effects on solar cell short circuit current (Isc) measurements on triple junction sub-cells. This work looks at several types of high altitude methods, direct high altitude meas urements near 120 kft, and lower stratospheric Langley plots from aircraft. It also looks at Langley extrapolation from altitudes above most of the ozone, for potential small balloon payloads. A convolution of the sub-cell spectral response with the standard solar spectrum modified by several absorption processes is used to determine the relative change from AMO, lscllsc(AMO). Rayleigh scattering, molecular scatterin g from uniformly mixed gases, Ozone, and water vapor, are included in this analysis. A range of atmosph eric pressures are examined, from 0. 05 to 0.25 Atm to cover the range of atmospheric altitudes where solar cell calibrations a reperformed. Generally these errors and uncertainties are less than 0.2%

  2. Altitude valve for railway suspension control system

    Science.gov (United States)

    Zhang, Xuan; Zhang, Lihao; Li, Qingxuan; Chen, WanSong

    2017-09-01

    With the variation of people and material during vehicle service, the gravity of vehicle could be unbalanced. As a result it might cause accident. In order to solve this problem, altitude valve is assembled on board. It can adjust the gravity of vehicle by the intake and outlet progress of the spring in the altitude valve to prevent the tilt of vehicles.

  3. High-altitude adaptations in vertebrate hemoglobins

    DEFF Research Database (Denmark)

    Weber, Roy E.

    2007-01-01

    Vertebrates at high altitude are subjected to hypoxic conditions that challenge aerobic metabolism. O2 transport from the respiratory surfaces to tissues requires matching between the O2 loading and unloading tensions and theO2-affinity of blood, which is an integrated function of hemoglobin......, birds and ectothermic vertebrates at high altitude....

  4. Hadronic jets an introduction

    CERN Document Server

    Banfi, Andrea

    2016-01-01

    Jet physics is an incredibly rich subject detailing the narrow cone of hadrons and other particles produced by the hadronization of a quark or gluon in a particle physics or heavy ion experiment. This book is a general overview of jet physics for scientists not directly involved in the field. It presents the basic experimental and theoretical problems arising when dealing with jets, and describing the solutions proposed in recent years.

  5. JET Joint Undertaking

    International Nuclear Information System (INIS)

    Keen, B.E.

    1988-03-01

    The paper is a JET progress report 1987, and covers the fourth full year of JET's operation. The report contains an overview summary of the scientific and technical advances during the year, and is supplemented by appendices of detailed contributions of the more important JET articles published during 1987. The document is aimed at specialists and experts engaged in nuclear fusion and plasma physics, as well as the general scientific community. (U.K.)

  6. 47 CFR 80.379 - Maritime frequencies assignable to aircraft stations.

    Science.gov (United States)

    2010-10-01

    ....300 MHz (5) 156.375 MHz (5) 156.400 MHz (5) 156.425 MHz (5) 156.450 MHz (5) 156.625 MHz (5) 156.800... aircraft stations does not exceed 300 meters (1,000 feet), except for reconnaissance aircraft participating in icebreaking operations where an altitude of 450 meters (1,500 feet) is allowed; (ii) The mean...

  7. Exergetic analysis of an aircraft turbojet engine with an afterburner

    OpenAIRE

    Ehyaei M.A.; Anjiridezfuli A.; Rosen M.A.

    2013-01-01

    An exergy analysis is reported of a J85-GE-21 turbojet engine and its components for two altitudes: sea level and 11,000 meters. The turbojet engine with afterburning operates on the Brayton cycle and includes six main parts: diffuser, compressor, combustion chamber, turbine, afterburner and nozzle. Aircraft data are utilized in the analysis with simulation data. The highest component exergy efficiency at sea level is observed to be for the compressor, at 9...

  8. Building Toward an Unmanned Aircraft System Training Strategy

    Science.gov (United States)

    2014-01-01

    and fly at altitudes higher than commercial airlines do. They file instrument flight rules flight plans. However, BAMS-D and Triton do not...incorporate sense-and-avoid technology, and conflicts can exist with visual flight rules aircraft in the airspace. Airspace issues exist at some Navy training...MODS, Washington, DC, February 2011, p. 1 of 10. 164 Peter La Franchi , “Directory: Unmanned Air Vehicles,” Flight International, June 21st, 2005, p. 56

  9. Numerical Calculation of Interaction Between Plane Jet and Subsonic Flow

    Directory of Open Access Journals (Sweden)

    V. O. Moskalenko

    2016-01-01

    Full Text Available The paper makes numerical calculation of interaction between plane jet and subsonic flow. Its aim is to determine the jet trajectory, velocity profiles, distribution of pressure coefficient on the plate surface at different jet angles, namely ωj=45°; 90°; 105° and at low blowing strengths ( ≤1.5 as well as a to make comparison with the experimental data of other authors.To simulate a two-dimensional jet in the subsonic flow the software package “CAD SolidWorks Flow Simulation” has been used. Initially, the test task was solved with its calculation results compared with experimental ones [6.8] in order to improve the convergence; the size of the computational domain and a computational grid within the k-ε turbulence model were selected. As a result of the calculation, were identified and analysed the pressure values, jet trajectories, and velocity profiles. In the graphs the solid lines show calculation results, and dots represent experimental data.From the calculation results it is seen that, with increasing intensity of the reduced mass flow ¯q in the above range, the change of the jet pressure coefficient p¯ distribution behind a slotted nozzle is almost linear and significant. Before the nozzle, with increasing ¯q the pressure coefficient increases slightly.Analysis of results has shown that blowing of jets with ωj>90ω, provides a greater perturbation of the subsonic flow. Thus, the jet penetrates into the flow deeper, forms a dead region of the greater length, and more significantly redistributes the pressure coefficient on the surface of the plate.The calculation results are in good compliance with the experimental data both for the jet axis and for the pressure coefficient distribution on the plate surface. The research results can be used in the designing the jet control of aircrafts.

  10. The hydrogen laminar jet

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez-Sanz, M. [Departamento de Motopropulsion y Termofluidomecanica, ETSI Aeronauticos, Universidad Politecnica de Madrid, 28040 Madrid (Spain); Rosales, M. [Department Ingenieria Termica y de Fluidos, Universidad Carlos III de Madrid, 28911, Leganes (Spain); Instituto de Innovacion en Mineria y Metalurgia, Avenida del Valle 738, Santiago (Chile); Sanchez, A.L. [Department Ingenieria Termica y de Fluidos, Universidad Carlos III de Madrid, 28911, Leganes (Spain)

    2010-04-15

    Numerical and asymptotic methods are used to investigate the structure of the hydrogen jet discharging into a quiescent air atmosphere. The analysis accounts in particular for the variation of the density and transport properties with composition. The Reynolds number of the flow R{sub j}, based on the initial jet radius a, the density {rho}{sub j} and viscosity {mu}{sub j} of the jet and the characteristic jet velocity u{sub j}, is assumed to take moderately large values, so that the jet remains slender and stable, and can be correspondingly described by numerical integration of the continuity, momentum and species conservation equations written in the boundary-layer approximation. The solution for the velocity and composition in the jet development region of planar and round jets, corresponding to streamwise distances of order R{sub j}a, is computed numerically, along with the solutions that emerge both in the near field and in the far field. The small value of the hydrogen-to-air molecular weight ratio is used to simplify the solution by considering the asymptotic limit of vanishing jet density. The development provides at leading-order explicit analytical expressions for the far-field velocity and hydrogen mass fraction that describe accurately the hydrogen jet near the axis. The information provided can be useful in particular to characterize hydrogen discharge processes from holes and cracks. (author)

  11. Properties of gluon jets

    International Nuclear Information System (INIS)

    Sugano, K.

    1987-01-01

    The properties of gluon jets are reviewed, and the measured characteristics are compared to the theoretical expectations. Although neither data nor models for the gluon jets are in the mature stage, in general the agreement between experiment and theory is remarkable. There are some intriguing differences. Since the properties of gluon jets are deeply rooted in the basic structure of non-Abelian gauge theory, the study of gluon jets casts further light on our understanding of QCD. Finally, the future prospects are discussed

  12. Properties of gluon jets

    International Nuclear Information System (INIS)

    Sugano, K.

    1988-01-01

    The properties of gluon jets are reviewed from an experimental point of view. The measured characteristics are compared to theoretical expectations. Although neither data nor models for the gluon jets are in the mature stage, there are remarkable agreements and also intriguing disagreements between experiment and theory. Since much interesting data have begun to emerge from various experiments and the properties of gluon jets are deeply rooted in the basic structure of non-Abelian gauge theory, the study of gluon jets casts further light on understanding of QCD. The future prospects are discussed

  13. Are jets really there

    International Nuclear Information System (INIS)

    Lillethun, E.

    1976-09-01

    Based on the results of high energy proton-proton collisions obtained at the CERN ISR in 1972-73, the production of 'jets' is discussed. Jets in e + e - collisions are also discussed and the parameters 'sphericity' and 'rapidity' are used in analysis of the data. The jets studied have been defined as having at least one particle of high transverse momentum. It is not clear whether the jets represent new physics or are another way of stating that resonances (rho,K*, Δ, N* etc.) are produced with high p(sub T), and that in such production the high transverse momentum must be balanced essentially locally in the collision. (JIW)

  14. Experimental study of hydrogen jet ignition and jet extinguishment

    International Nuclear Information System (INIS)

    Wierman, R.W.

    1979-04-01

    Two phases are described of an experimental study that investigated: (1) the ignition characteristics of hydrogen--sodium jets, (2) the formation of hydrogen in sodium--humid air atmospheres, and (3) the extinguishment characteristics of burning hydrogen--sodium jets. Test conditions were similar to those postulated for highly-improbable breeder reactor core melt-through accidents and included: jet temperature, jet velocity, jet hydrogen concentration, jet sodium concentration, atmospheric oxygen concentration, and atmospheric water vapor concentration

  15. Performance of portable ventilators at altitude.

    Science.gov (United States)

    Blakeman, Thomas; Britton, Tyler; Rodriquez, Dario; Branson, Richard

    2014-09-01

    Aeromedical transport of critically ill patients requires continued, accurate performance of equipment at altitude. Changes in barometric pressure can affect the performance of mechanical ventilators calibrated for operation at sea level. Deploying ventilators that can maintain a consistent tidal volume (VT) delivery at various altitudes is imperative for lung protection when transporting wounded war fighters to each echelon of care. Three ventilators (Impact 731, Hamilton T1, and CareFusion Revel) were tested at pediatric (50 and 100 mL) and adult (250-750 mL) tidal VTs at 0 and 20 cm H₂O positive end expiratory pressure and at inspired oxygen of 0.21 and 1.0. Airway pressure, volume, and flow were measured at sea level as well as at 8,000, 16,000, and 22,000 ft (corresponding to barometric pressures of 760, 564, 412, and 321 mm Hg) using a calibrated pneumotachograph connected to a training test lung in an altitude chamber. Set VT and delivered VT as well as changes in VT at each altitude were compared by t test. The T1 delivered VT within 10% of set VT at 8,000 ft. The mean VT was less than set VT at sea level as a result of circuit compressible volume with the Revel and the 731. Changes in VT varied widely among the devices at sea level and at altitude. Increasing altitudes resulted in larger VT than set for the Revel and the T1. The 731 compensated for changes in altitude delivered VT within 10% at the adult settings at all altitudes. Altitude compensation is an active software algorithm. Only the 731 actively accounts for changes in barometric pressure to maintain the set VT at all tested altitudes.

  16. Jet mass spectra in Higgs+one jet at NNLL

    International Nuclear Information System (INIS)

    Jouttenus, Teppo T.; Stewart, Iain W.; Waalewijn, Wouter J.

    2013-02-01

    The invariant mass of a jet is a benchmark variable describing the structure of jets at the LHC. We calculate the jet mass spectrum for Higgs plus one jet at the LHC at next-to-next-to-leading logarithmic (NNLL) order using a factorization formula. At this order, the cross section becomes sensitive to perturbation theory at the soft m 2 jet /p jet T scale. Our calculation is exclusive and uses the 1-jettiness global event shape to implement a veto on additional jets. The dominant dependence on the jet veto is removed by normalizing the spectrum, leaving residual dependence from non-global logarithms depending on the ratio of the jet mass and jet veto variables. For our exclusive jet cross section these non-global logarithms are parametrically smaller than in the inclusive case, allowing us to obtain a complete NNLL result. Results for the dependence of the jet mass spectrum on the kinematics, jet algorithm, and jet size R are given. Using individual partonic channels we illustrate the difference between the jet mass spectra for quark and gluon jets. We also study the effect of hadronization and underlying event on the jet mass in Pythia. To highlight the similarity of inclusive and exclusive jet mass spectra, a comparison to LHC data is presented.

  17. Jet mass spectra in Higgs+one jet at NNLL

    Energy Technology Data Exchange (ETDEWEB)

    Jouttenus, Teppo T.; Stewart, Iain W. [Massachusetts Institute of Technology, Cambridge, MA (United States). Center for Theoretical Physics; Tackmann, Frank J. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Waalewijn, Wouter J. [California Univ., San Diego, La Jolla, CA (United States). Dept. of Physics

    2013-02-15

    The invariant mass of a jet is a benchmark variable describing the structure of jets at the LHC. We calculate the jet mass spectrum for Higgs plus one jet at the LHC at next-to-next-to-leading logarithmic (NNLL) order using a factorization formula. At this order, the cross section becomes sensitive to perturbation theory at the soft m{sup 2}{sub jet}/p{sup jet}{sub T} scale. Our calculation is exclusive and uses the 1-jettiness global event shape to implement a veto on additional jets. The dominant dependence on the jet veto is removed by normalizing the spectrum, leaving residual dependence from non-global logarithms depending on the ratio of the jet mass and jet veto variables. For our exclusive jet cross section these non-global logarithms are parametrically smaller than in the inclusive case, allowing us to obtain a complete NNLL result. Results for the dependence of the jet mass spectrum on the kinematics, jet algorithm, and jet size R are given. Using individual partonic channels we illustrate the difference between the jet mass spectra for quark and gluon jets. We also study the effect of hadronization and underlying event on the jet mass in Pythia. To highlight the similarity of inclusive and exclusive jet mass spectra, a comparison to LHC data is presented.

  18. Integral bubble and jet models with pressure forces

    Science.gov (United States)

    Vulfson, A. N.; Nikolaev, P. V.

    2017-07-01

    Modifications of integral bubble and jet models including the pressure force are proposed. Exact solutions are found for the modified model of a stationary convective jet from a point source of buoyancy and momentum. The exact solutions are compared against analytical solutions of the integral models for a stationary jet that are based on the approximation of the vertical boundary layer. It is found that the modified integral models of convective jets retain the power-law dependences on the altitude for the vertical velocity and buoyancy obtained in classical models. For a buoyant jet in a neutrally stratified atmosphere, the inclusion of the pressure force increases the amplitude of buoyancy and decreases the amplitude of vertical velocity. The total amplitude change is about 10%. It is shown that in this model there is a dynamic invariant expressing the law of a uniform distribution of the potential and kinetic energy along the jet axis. For a spontaneous jet rising in an unstably stratified atmosphere, the inclusion of the pressure force retains the amplitude of buoyancy and increases the amplitude of vertical velocity by about 15%. It is shown that in the model of a spontaneous jet there is a dynamic invariant expressing the law of a uniform distribution of the available potential and kinetic energy along the jet axis. The results are of interest for the problems of anthropogenic pollution diffusion in the air and water environments and the formulation of models for statistical and stochastic ensembles of thermals in a mass-flux parameterization of turbulent moments.

  19. Research on electrostatic electrification during jet kerosene spraying

    International Nuclear Information System (INIS)

    Liu, Quanzhen; Li, Yipeng; Zhang, Wentian; Sun, Keping

    2013-01-01

    Multiple electrostatic electrifications during aircraft fuelling process may cause a fire disaster or explosion, so study on the protection measure for electrostatic electrification is very important for the security of aircraft fuelling. This paper investigated the electrostatic voltage and charge of the fuel nozzle and metal parts during the fuel spraying by self-designed jet kerosene spraying electrostatic electrification test system. The experimental results indicate that the voltage on the fuel nozzle and metal parts is very dangerous for electrostatic safety if they are not reliably grounded.

  20. Venturi Air-Jet Vacuum Ejector For Sampling Air

    Science.gov (United States)

    Hill, Gerald F.; Sachse, Glen W.; Burney, L. Garland; Wade, Larry O.

    1990-01-01

    Venturi air-jet vacuum ejector pump light in weight, requires no electrical power, does not contribute heat to aircraft, and provides high pumping speeds at moderate suctions. High-pressure motive gas required for this type of pump bled from compressor of aircraft engine with negligible effect on performance of engine. Used as source of vacuum for differential-absorption CO-measurement (DACOM), modified to achieve in situ measurements of CO at frequency response of 10 Hz. Provides improvement in spatial resolution and potentially leads to capability to measure turbulent flux of CO by use of eddy-correlation technique.

  1. Jet physics in ALICE

    International Nuclear Information System (INIS)

    Loizides, C.A.

    2005-01-01

    The ALICE experiment is one of the experiments currently prepared for the Large Hadron Collider (LHC) at CERN, Geneva, starting operation end of 2007. ALICE is dedicated to the research on nucleus-nucleus collisions at ultra-relativistic energies, which addresses the properties of strongly interacting matter under varying conditions of high density and temperature. The conditions provided at the LHC allow significant qualitative improvement with respect to previous studies. In particular, energetic probes, light quarks and gluons, will be abundantly produced. These probes might be identified by their fragmentation into correlated particles, so called jets, of high enough energy to allow full reconstruction of jet properties; even in the underlying heavy-ion environment. Understanding the dependence of high-energy jet production and fragmentation influenced by the dense medium created in the collision region is an open field of active research. Generally, one expects energy loss of the probes due to medium-induced gluon radiation. It is suggested that hadronization products of these, rather soft gluons may be contained within the jet emission cone, resulting in a modification of the characteristic jet fragmentation, as observed via longitudinal and transverse momentum distributions with respect to the direction of the initial parton, as well as of the multiplicity distributions arising from the jet fragmentation. Particle momenta parallel to the jet axis are softened (jet quenching), while transverse to it increased (transverse heating). The present thesis studies the capabilities of the ALICE detectors to measure these jets and quantifies obtainable rates and the quality of jet reconstruction, in both proton-proton and lead-lead collisions at the LHC. In particular, it is addressed whether modification of the jet fragmentation can be detected within the high-particle-multiplicity environment of central lead-lead collisions. (orig.)

  2. Deformations of free jets

    Science.gov (United States)

    Paruchuri, Srinivas

    This thesis studies three different problems. First we demonstrate that a flowing liquid jet can be controllably split into two separate subfilaments through the applications of a sufficiently strong tangential stress to the surface of the jet. In contrast, normal stresses can never split a liquid jet. We apply these results to observations of uncontrolled splitting of jets in electric fields. The experimental realization of controllable jet splitting would provide an entirely novel route for producing small polymeric fibers. In the second chapter we present an analytical model for the bending of liquid jets and sheets from temperature gradients, as recently observed by Chwalek et al. [Phys. Fluids, 14, L37 (2002)]. The bending arises from a local couple caused by Marangoni forces. The dependence of the bending angle on experimental parameters is presented, in qualitative agreement with reported experiments. The methodology gives a simple framework for understanding the mechanisms for jet and sheet bending. In chapter 4 we address the discrepancy between hydrodynamic theory of liquid jets, and the snap-off of narrow liquid jets observed in molecular dynamics (MD) simulations [23]. This has been previously attributed to the significant role of thermal fluctuations in nanofluidic systems. We argue that hydrodynamic description of such systems should include corrections to the Laplace pressure which result from the failure of the sharp interface assumption when the jet diameter becomes small enough. We show that this effect can in principle give rise to jet shapes similar to those observed in MD simulations, even when thermal fluctuations are completely neglected. Finally we summarize an algorithm developed to simulate droplet impact on a smooth surface.

  3. In-situ studies on volatile jet exhaust particle emissions - impacts of fuel sulfur content and environmental conditions on nuclei-mode aerosols

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, F.; Baumann, R.; Petzold, A.; Busen, R.; Schulte, P.; Fiebig, M. [DLR Deutsches Zentrum fuer Luft- und Raumfahrt e.V., Wessling (Germany). Inst. fuer Physik der Atmosphaere; Brock, C.A. [Denver Univ., CO (United States). Dept. of Engineering

    2000-02-01

    In-situ measurements of ultrafine aerosol particle emissions were performed at cruise altitudes behind the DLR ATTAS research jet (RR M45H M501 engines) and a B737-300 aircraft (CFM56-3B1 engines). Measurements were made 0.15-20 seconds after emission as the source aircraft burned fuel with sulfur contents (FSC) of 2.6, 56 or 118 mg kg{sup -1}. Particle size distributions of from 3 to 60 nm diameter were determined using CN-counters with varying lower size detection limits. Volatile particle concentrations in the aircraft plumes strongly increased as diameter decreased toward the sizes of large molecular clusters, illustrating that apparent particle emissions are extremely sensitive to the smallest particle size detectable by the instrument used. Environmental conditions and plume age alone could influence the number of detected ultrafine (volatile) aerosols within an order of magnitude, as well. The observed volatile particle emissions decreased nonlinearly as FSC decreased to 60 mg kg{sup -1}, reaching minimum values of about 2 x 10{sup 17} kg{sup -1} and 2 x 10{sup 16} kg{sup -1} for particles >3 nm and >5 nm, respectively. Volatile particle emissions did not change significantly as FSCs were further reduced below 60 mg kg{sup -1}. Volatile particle emissions did not differ significantly between the two studied engine types. In contrast, soot particle emissions from the modern CFM56-3B1 engines were 4-5 times less (4 x 10{sup 14} kg{sup -1}) than from the older RR M45H M501 engines (1.8 x 10{sup 15} kg{sup -1}). Contrail processing has been identified as an efficient sink/quenching parameter for ultrafine particles and reduces the remaining interstitial aerosol by factors 2-10 depending on particle size.

  4. Atmospheric Sampling of Aerosols to Stratospheric Altitudes using High Altitude Balloons

    Science.gov (United States)

    Jerde, E. A.; Thomas, E.

    2010-12-01

    Although carbon dioxide represents a long-lived atmospheric component relevant to global climate change, it is also understood that many additional contributors influence the overall climate of Earth. Among these, short-lived components are more difficult to incorporate into models due to uncertainties in the abundances of these both spatially and temporally. Possibly the most significant of these short-lived components falls under the heading of “black carbon” (BC). There are numerous overlapping definitions of BC, but it is basically carbonaceous in nature and light absorbing. Due to its potential as a climate forcer, an understanding of the BC population in the atmosphere is critical for modeling of radiative forcing. Prior measurements of atmospheric BC generally consist of airplane- and ground-based sampling, typically below 5000 m and restricted in time and space. Given that BC has a residence time on the order of days, short-term variability is easily missed. Further, since the radiative forcing is a result of BC distributed through the entire atmospheric column, aircraft sampling is by definition incomplete. We are in the process of planning a more comprehensive sampling of the atmosphere for BC using high-altitude balloons. Balloon-borne sampling is a highly reliable means to sample air through the entire troposphere and into the lower stratosphere. Our system will incorporate a balloon and a flight train of two modules. One module will house an atmospheric sampler. This sampler will be single-stage (samples all particle sizes together), and will place particles directly on an SEM sample stub for analysis. The nozzle depositing the sample will be offset from the center of the stub, placing the aerosol particles toward the edge. At various altitudes, the stub will be rotated 45 degrees, providing 6-8 sample “cuts” of particle populations through the atmospheric column. The flights will reach approximately 27 km altitude, above which the balloons

  5. Night vision imaging systems design, integration, and verification in military fighter aircraft

    Science.gov (United States)

    Sabatini, Roberto; Richardson, Mark A.; Cantiello, Maurizio; Toscano, Mario; Fiorini, Pietro; Jia, Huamin; Zammit-Mangion, David

    2012-04-01

    rear cockpits at the various stages of the test campaign. This process allowed a considerable enhancement of the TORNADO NVIS configuration, giving a good medium-high level NVG operational capability to the aircraft. Further developments also include the design, integration and test of internal/external lighting for the Italian TORNADO "Mid Life Update" (MLU) and other programs, such as the AM-X aircraft internal/external lights modification/testing and the activities addressing low-altitude NVG operations with fast jets (e.g., TORNADO, AM-X, MB-339CD), a major issue being the safe ejection of aircrew with NVG and NVG modified helmets. Two options have been identified for solving this problem: namely the modification of the current Gentex HGU-55 helmets and the design of a new helmet incorporating a reliable NVG connection/disconnection device (i.e., a mechanical system fully integrated in the helmet frame), with embedded automatic disconnection capability in case of ejection.

  6. COUNTERROTATION IN MAGNETOCENTRIFUGALLY DRIVEN JETS AND OTHER WINDS

    Energy Technology Data Exchange (ETDEWEB)

    Sauty, C.; Cayatte, V. [Laboratoire Univers et Theories, Observatoire de Paris, UMR 8102 du CNRS, Universite Paris Diderot, F-92190 Meudon (France); Lima, J. J. G. [Centro de Astrofisica, Universidade do Porto, Rua das Estrelas, 4150-762 Porto (Portugal); Matsakos, T. [CEA, IRAMIS, Service Photons, Atomes et Molecules, F-91191 Gif-sur-Yvette (France); Tsinganos, K., E-mail: christophe.sauty@obspm.fr [IASA and Section of Astrophysics, Astronomy and Mechanics, Department of Physics, University of Athens, Panepistimiopolis GR-157 84, Zografos (Greece)

    2012-11-01

    Rotation measurement in jets from T Tauri stars is a rather difficult task. Some jets seem to be rotating in a direction opposite to that of the underlying disk, although it is not yet clear if this affects the totality or part of the outflows. On the other hand, Ulysses data also suggest that the solar wind may rotate in two opposite ways between the northern and southern hemispheres. We show that this result is not as surprising as it may seem and that it emerges naturally from the ideal MHD equations. Specifically, counterrotating jets neither contradict the magnetocentrifugal driving of the flow nor prevent extraction of angular momentum from the disk. The demonstration of this result is shown by combining the ideal MHD equations for steady axisymmetric flows. Provided that the jet is decelerated below some given threshold beyond the Alfven surface, the flow will change its direction of rotation locally or globally. Counterrotation is also possible for only some layers of the outflow at specific altitudes along the jet axis. We conclude that the counterrotation of winds or jets with respect to the source, star or disk, is not in contradiction with the magnetocentrifugal driving paradigm. This phenomenon may affect part of the outflow, either in one hemisphere, or only in some of the outflow layers. From a time-dependent simulation, we illustrate this effect and show that it may not be permanent.

  7. Optimal trajectories of aircraft and spacecraft

    Science.gov (United States)

    Miele, A.

    1990-01-01

    Work done on algorithms for the numerical solutions of optimal control problems and their application to the computation of optimal flight trajectories of aircraft and spacecraft is summarized. General considerations on calculus of variations, optimal control, numerical algorithms, and applications of these algorithms to real-world problems are presented. The sequential gradient-restoration algorithm (SGRA) is examined for the numerical solution of optimal control problems of the Bolza type. Both the primal formulation and the dual formulation are discussed. Aircraft trajectories, in particular, the application of the dual sequential gradient-restoration algorithm (DSGRA) to the determination of optimal flight trajectories in the presence of windshear are described. Both take-off trajectories and abort landing trajectories are discussed. Take-off trajectories are optimized by minimizing the peak deviation of the absolute path inclination from a reference value. Abort landing trajectories are optimized by minimizing the peak drop of altitude from a reference value. Abort landing trajectories are optimized by minimizing the peak drop of altitude from a reference value. The survival capability of an aircraft in a severe windshear is discussed, and the optimal trajectories are found to be superior to both constant pitch trajectories and maximum angle of attack trajectories. Spacecraft trajectories, in particular, the application of the primal sequential gradient-restoration algorithm (PSGRA) to the determination of optimal flight trajectories for aeroassisted orbital transfer are examined. Both the coplanar case and the noncoplanar case are discussed within the frame of three problems: minimization of the total characteristic velocity; minimization of the time integral of the square of the path inclination; and minimization of the peak heating rate. The solution of the second problem is called nearly-grazing solution, and its merits are pointed out as a useful

  8. ABOUT TRANSITION ALTITUDE IN RUSSIAN FEDERATION

    Directory of Open Access Journals (Sweden)

    2016-01-01

    Full Text Available This article is about establishing a common transition altitude over all territory of Russian Federation. The main objective is to prove the necessity of a common transition altitude in Russian airspace and to define, which variant of tran- sition altitude (low, medium, high is the most suitable to be implemented in Russia. ICAO and IFALPA points of view, data and experience from different states and regions all over the world were examined in order to show all the advantages and disadvantages of different approaches towards common transition altitude. The research showed that the most appro- priate common transition altitude in Russia will be 10000 feet (3050 meters, it will cover almost all the international aero- dromes and regions in the country. Only several exceptions are needed in mountainous areas. This article can be used to further study of the possibility of implementation of common transition altitude, because it can’t take into consideration all the local features of all the FIRs (Flight Information Regions in Russia. The conclusion is establishing a common transi- tion altitude over such a big part of the world as Russian Federation will lead to improvement of the flight safety, harmoni- zation with ICAO and IFALPA policies and flexibility in airspace design.

  9. High Altitude Launch for a Practical SSTO

    Science.gov (United States)

    Landis, Geoffrey A.; Denis, Vincent

    2003-01-01

    Existing engineering materials allow the constuction of towers to heights of many kilometers. Orbital launch from a high altitude has significant advantages over sea-level launch due to the reduced atmospheric pressure, resulting in lower atmospheric drag on the vehicle and allowing higher rocket engine performance. High-altitude launch sites are particularly advantageous for single-stage to orbit (SSTO) vehicles, where the payload is typically 2% of the initial launch mass. An earlier paper enumerated some of the advantages of high altitude launch of SSTO vehicles. In this paper, we calculate launch trajectories for a candidate SSTO vehicle, and calculate the advantage of launch at launch altitudes 5 to 25 kilometer altitudes above sea level. The performance increase can be directly translated into increased payload capability to orbit, ranging from 5 to 20% increase in the mass to orbit. For a candidate vehicle with an initial payload fraction of 2% of gross lift-off weight, this corresponds to 31% increase in payload (for 5-km launch altitude) to 122% additional payload (for 25-km launch altitude).

  10. Differences in Characteristics of Aviation Accidents During 1993-2012 Based on Aircraft Type

    Science.gov (United States)

    Evans, Joni K.

    2015-01-01

    Civilian aircraft are available in a variety of sizes, engine types, construction materials and instrumentation complexity. For the analysis reported here, eleven aircraft categories were developed based mostly on aircraft size and engine type, and these categories were applied to twenty consecutive years of civil aviation accidents. Differences in various factors were examined among these aircraft types, including accident severity, pilot characteristics and accident occurrence categories. In general, regional jets and very light sport aircraft had the lowest rates of adverse outcomes (injuries, fatal accidents, aircraft destruction, major accidents), while aircraft with twin (piston) engines or with a single (piston) engine and retractable landing gear carried the highest incidence of adverse outcomes. The accident categories of abnormal runway contact, runway excursions and non-powerplant system/component failures occur frequently within all but two or three aircraft types. In contrast, ground collisions, loss of control - on ground/water and powerplant system/component failure occur frequently within only one or two aircraft types. Although accidents in larger aircraft tend to have less severe outcomes, adverse outcome rates also differ among accident categories. It may be that the type of accident has as much or more influence on the outcome as the type of aircraft.

  11. Quark jets, gluon jets and the three-gluon vertex

    International Nuclear Information System (INIS)

    Fodor, Z.

    1989-11-01

    Using hadronic jets in electron-positron annihilation, we suggest a simple and model-independent method to see the differences between quark and gluon jets. We define and analyse special energy dependent moments of jets and choose those which are the most characteristic to the jet type. The method handles the energy of a jet in an adequate way. We discuss new methods using jet flavor tagging, ordinary flavor tagging of a definite quark jet or discrimination between quark and gluon jets, to test the triple-gluon vertex in electron-positron annihilation. An enriched sample of gluon jets, jets with the smallest energy in four-jet events, as well as a continuous tagging variable are also studied. 21 refs., 6 figs. (Author)

  12. Generation of elves by sprites and jets

    International Nuclear Information System (INIS)

    Taranenko, Y.; Roussel-Dupre, R.; Yukhimuk, V.; Symbalisty, E.

    1997-01-01

    Recent years of observations of the upper atmosphere and the lower ionosphere brought a fascinating collection of new phenomena including optical, radio, and gamma-ray emissions originating in the 20 to 90 km altitude range. Up to now, the most diverse phenomenology has emerged from the optical observations which have led to the identification of red sprites, blue jets, blue starts, and elves. Most of the studies have concentrated on relating such phenomena in the upper atmosphere to regular lightning discharges in the troposphere. The sprite/jet discharge itself can be caused by the runaway air breakdown, or regular air breakdown. The standard theory for optical airglow transients in the lower ionosphere above the thunderstorms also known as elves suggests that they are produced during interaction of electromagnetic pulses (EMP) from lightning with the lower ionosphere. Heating of the ambient electrons by the EMP in the D region can result in excitation of optical emissions once the optical excitation thresholds are reached. In this paper the authors suggest that in addition to this mechanism elves can be caused by an EMP generated by sprites and jets

  13. JET Joint Undertaking

    International Nuclear Information System (INIS)

    Keen, B.E.

    1987-03-01

    The paper presents the progress report of the Joint European Torus (JET) Joint Undertaking, 1986. The report contains a survey of the scientific and technical achievements on JET during 1986; the more important articles referred to in this survey are reproduced as appendices to this Report. The last section discusses developments which might improve the overall performance of the machine. (U.K.)

  14. Warranties for the Navy F-404 Jet Aircraft Engine

    National Research Council Canada - National Science Library

    Young, Shelton

    1994-01-01

    .... The courtesies extended to the audit staff are appreciated. If you have any questions on this audit, please contact Mr. Christian Hendricks, Program Director, at (703) 692-3394 (DSN 222-3394) or Mr. James Kornides, Project Manager. at (703) 692-3420 (DSN 222-3420). The planned distribution of this report is in Appendix H. The audit team members are listed inside the back cover.

  15. Pollution reduction technology program small jet aircraft engines, phase 3

    Science.gov (United States)

    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.

  16. Jet physics at CDF

    International Nuclear Information System (INIS)

    Melese, P.

    1997-05-01

    We present high E T jet measurements from CDF at the Fermilab Tevatron Collider. The incfilusive jet cross section at √s = 1800 GeV with ∼ 5 times more data is compared to the published CDF results, preliminary D0 results, and next-to-leading order QCD predictions. The summation E T cross section is also compared to QCD predictions and the dijet angular distribution is used to place a limit on quark compositeness. The inclusive jet cross section at √s = 630 GeV is compared with that at 1800 GeV to test the QCD predictions for the scaling of jet cross sections with √s. Finally, we present momentum distributions of charged particles in jets and compare them to Modified Leading Log Approximation predictions

  17. Jet physics in ATLAS

    CERN Multimedia

    CERN. Geneva

    2012-01-01

    Measurements of hadronic jets provide tests of strong interactions which are interesting both in their own right and as backgrounds to many New Physics searches. It is also through tests of Quantum Chromodynamics that new physics may be discovered. The extensive dataset recorded with the ATLAS detector throughout the 7 TeV centre-of-mass LHC operation period allows QCD to be probed at distances never reached before. We present a review of selected ATLAS jet performance and physics measurements, together with results from new physics searches using the 2011 dataset. They include studies of the underlying event and fragmentation models, measurements of the inclusive jet, dijet and multijet cross sections, parton density functions, heavy flavours, jet shape, mass and substructure. Searches for new physics in monojet, dijet and photon-jet final states are also presented.

  18. Cosmic radiation dose in aircraft - a neutron track etch detector

    Energy Technology Data Exchange (ETDEWEB)

    Vukovic, B.; Radolic, V.; Miklavcic, I.; Poje, M.; Varga, M. [Department of Physics, University of Osijek, 31000 Osijek, P.O. Box 125, Gajev trg 6 (Croatia); Planinic, J. [Department of Physics, University of Osijek, 31000 Osijek, P.O. Box 125, Gajev trg 6 (Croatia)], E-mail: planinic@ffos.hr

    2007-12-15

    Cosmic radiation bombards us at high altitude by ionizing particles. The radiation environment is a complex mixture of charged particles of solar and galactic origin, as well as of secondary particles produced in interaction of the galactic cosmic particles with the nuclei of atmosphere of the Earth. The radiation field at aircraft altitude consists of different types of particles, mainly photons, electrons, positrons and neutrons, with a large energy range. The non-neutron component of cosmic radiation dose aboard ATR 42 and A 320 aircrafts (flight level of 8 and 11 km, respectively) was measured with TLD-100 (LiF:Mg,Ti) detectors and the Mini 6100 semiconductor dosimeter. The estimated occupational effective dose for the aircraft crew (A 320) working 500 h per year was 1.64 mSv. Other experiments, or dose rate measurements with the neutron dosimeter, consisting of LR-115 track detector and boron foil BN-1 or 10B converter, were performed on five intercontinental flights. Comparison of the dose rates of the non-neutron component (low LET) and the neutron one (high LET) of the radiation field at the aircraft flight level showed that the neutron component carried about 50% of the total dose. The dose rate measurements on the flights from the Middle Europe to the South and Middle America, then to Korea and Japan, showed that the flights over or near the equator region carried less dose rate; this was in accordance with the known geomagnetic latitude effect.

  19. Cosmic radiation dose in aircraft - a neutron track etch detector

    International Nuclear Information System (INIS)

    Vukovic, B.; Radolic, V.; Miklavcic, I.; Poje, M.; Varga, M.; Planinic, J.

    2007-01-01

    Cosmic radiation bombards us at high altitude by ionizing particles. The radiation environment is a complex mixture of charged particles of solar and galactic origin, as well as of secondary particles produced in interaction of the galactic cosmic particles with the nuclei of atmosphere of the Earth. The radiation field at aircraft altitude consists of different types of particles, mainly photons, electrons, positrons and neutrons, with a large energy range. The non-neutron component of cosmic radiation dose aboard ATR 42 and A 320 aircrafts (flight level of 8 and 11 km, respectively) was measured with TLD-100 (LiF:Mg,Ti) detectors and the Mini 6100 semiconductor dosimeter. The estimated occupational effective dose for the aircraft crew (A 320) working 500 h per year was 1.64 mSv. Other experiments, or dose rate measurements with the neutron dosimeter, consisting of LR-115 track detector and boron foil BN-1 or 10B converter, were performed on five intercontinental flights. Comparison of the dose rates of the non-neutron component (low LET) and the neutron one (high LET) of the radiation field at the aircraft flight level showed that the neutron component carried about 50% of the total dose. The dose rate measurements on the flights from the Middle Europe to the South and Middle America, then to Korea and Japan, showed that the flights over or near the equator region carried less dose rate; this was in accordance with the known geomagnetic latitude effect

  20. Do supersonic aircraft avoid contrails?

    Directory of Open Access Journals (Sweden)

    A. Stenke

    2008-02-01

    Full Text Available The impact of a potential future fleet of supersonic aircraft on contrail coverage and contrail radiative forcing is investigated by means of simulations with the general circulation model ECHAM4.L39(DLR including a contrail parameterization. The model simulations consider air traffic inventories of a subsonic fleet and of a combined fleet of sub- and supersonic aircraft for the years 2025 and 2050, respectively. In case of the combined fleet, part of the subsonic fleet is replaced by supersonic aircraft. The combined air traffic scenario reveals a reduction in contrail cover at subsonic cruise levels (10 to 12 km in the northern extratropics, especially over the North Atlantic and North Pacific. At supersonic flight levels (18 to 20 km, contrail formation is mainly restricted to tropical regions. Only in winter is the northern extratropical stratosphere above the 100 hPa level cold enough for the formation of contrails. Total contrail coverage is only marginally affected by the shift in flight altitude. The model simulations indicate a global annual mean contrail cover of 0.372% for the subsonic and 0.366% for the combined fleet in 2050. The simulated contrail radiative forcing is most closely correlated to the total contrail cover, although contrails in the tropical lower stratosphere are found to be optically thinner than contrails in the extratropical upper troposphere. The global annual mean contrail radiative forcing in 2050 (2025 amounts to 24.7 mW m−2 (9.4 mW m−2 for the subsonic fleet and 24.2 mW m−2 (9.3 mW m−2 for the combined fleet. A reduction of the supersonic cruise speed from Mach 2.0 to Mach 1.6 leads to a downward shift in contrail cover, but does not affect global mean total contrail cover and contrail radiative forcing. Hence the partial substitution of subsonic air traffic leads to a shift of contrail occurrence from mid to low latitudes, but the resulting change in

  1. Control Design for a Generic Commercial Aircraft Engine

    Science.gov (United States)

    Csank, Jeffrey; May, Ryan D.

    2010-01-01

    This paper describes the control algorithms and control design process for a generic commercial aircraft engine simulation of a 40,000 lb thrust class, two spool, high bypass ratio turbofan engine. The aircraft engine is a complex nonlinear system designed to operate over an extreme range of environmental conditions, at temperatures from approximately -60 to 120+ F, and at altitudes from below sea level to 40,000 ft, posing multiple control design constraints. The objective of this paper is to provide the reader an overview of the control design process, design considerations, and justifications as to why the particular architecture and limits have been chosen. The controller architecture contains a gain-scheduled Proportional Integral controller along with logic to protect the aircraft engine from exceeding any limits. Simulation results illustrate that the closed loop system meets the Federal Aviation Administration s thrust response requirements

  2. Proceedings of a Workshop on V/STOL Aircraft Aerodynamics. Volume I. Held at Naval Postgraduate School Monterey, California 16-18 May 1979,

    Science.gov (United States)

    1979-05-18

    jets in a crossflow being conducted by the Computational Mechanics Corp. The Vought VAPE program will incorporate - in addition to the Wooler-Ziegler...Beatty Vought Corporation Dallas, TX This paper describes the V/STOL Aircraft Propulsive Effects Computer Program ( VAPE ), developed at the Vought...regions of flight. The VAPE program is capable of evaluating: o effects of relative wind about the aircraft o effects of propulsive lift jet entrainment

  3. Analysis of Nozzle Jet Plume Effects on Sonic Boom Signature

    Science.gov (United States)

    Bui, Trong

    2010-01-01

    An axisymmetric full Navier-Stokes computational fluid dynamics (CFD) study was conducted to examine nozzle exhaust jet plume effects on the sonic boom signature of a supersonic aircraft. A simplified axisymmetric nozzle geometry, representative of the nozzle on the NASA Dryden NF-15B Lift and Nozzle Change Effects on Tail Shock (LaNCETS) research airplane, was considered. The highly underexpanded nozzle flow is found to provide significantly more reduction in the tail shock strength in the sonic boom N-wave pressure signature than perfectly expanded and overexpanded nozzle flows. A tail shock train in the sonic boom signature, similar to what was observed in the LaNCETS flight data, is observed for the highly underexpanded nozzle flow. The CFD results provide a detailed description of the nozzle flow physics involved in the LaNCETS nozzle at different nozzle expansion conditions and help in interpreting LaNCETS flight data as well as in the eventual CFD analysis of a full LaNCETS aircraft. The current study also provided important information on proper modeling of the LaNCETS aircraft nozzle. The primary objective of the current CFD research effort was to support the LaNCETS flight research data analysis effort by studying the detailed nozzle exhaust jet plume s imperfect expansion effects on the sonic boom signature of a supersonic aircraft. Figure 1 illustrates the primary flow physics present in the interaction between the exhaust jet plume shock and the sonic boom coming off of an axisymmetric body in supersonic flight. The steeper tail shock from highly expanded jet plume reduces the dip of the sonic boom N-wave signature. A structured finite-volume compressible full Navier-Stokes CFD code was used in the current study. This approach is not limited by the simplifying assumptions inherent in previous sonic boom analysis efforts. Also, this study was the first known jet plume sonic boom CFD study in which the full viscous nozzle flow field was modeled, without

  4. Process analysis of the modelled 3-D mesoscale impact of aircraft emissions on the atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Hendricks, J; Ebel, A; Lippert, E; Petry, H [Koeln Univ. (Germany). Inst. fuer Geophysik und Meterorologie

    1998-12-31

    A mesoscale chemistry transport model is applied to study the impact of aircraft emissions on the atmospheric trace gas composition. A special analysis of the simulations is conducted to separate the effects of chemistry, transport, diffusion and cloud processes on the transformation of the exhausts of a subsonic fleet cruising over the North Atlantic. The aircraft induced ozone production strongly depends on the tropopause height and the cruise altitude. Aircraft emissions may undergo an effective downward transport under the influence of stratosphere-troposphere exchange activity. (author) 12 refs.

  5. Aircraft emission inventories for scheduled air traffic for the 1976-92 time period. Historical trends

    Energy Technology Data Exchange (ETDEWEB)

    Baughcum, S L; Henderson, S C; Tritz, T G [Boeing Co., Seattle, WA (United States)

    1998-12-31

    Emission inventories of fuel burned, NO{sub x}, CO, and hydrocarbons have been calculated for scheduled air traffic in 1976, 1984, 1990 and 1992 on a 1 deg latitude x 1 deg longitude x 1 km pressure altitude grid. Using this database, the seasonal variation and historical trends in aircraft emissions have been calculated for selected geographical regions (e.g., North Atlantic, Europe, North America, North Pacific). The trend in emissions is a combination of the effects of passenger demand growth, improved aircraft efficiency, changes in combustor characteristics, and aircraft size. (author) 8 refs.

  6. Process analysis of the modelled 3-D mesoscale impact of aircraft emissions on the atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Hendricks, J.; Ebel, A.; Lippert, E.; Petry, H. [Koeln Univ. (Germany). Inst. fuer Geophysik und Meterorologie

    1997-12-31

    A mesoscale chemistry transport model is applied to study the impact of aircraft emissions on the atmospheric trace gas composition. A special analysis of the simulations is conducted to separate the effects of chemistry, transport, diffusion and cloud processes on the transformation of the exhausts of a subsonic fleet cruising over the North Atlantic. The aircraft induced ozone production strongly depends on the tropopause height and the cruise altitude. Aircraft emissions may undergo an effective downward transport under the influence of stratosphere-troposphere exchange activity. (author) 12 refs.

  7. Aircraft emission inventories for scheduled air traffic for the 1976-92 time period. Historical trends

    Energy Technology Data Exchange (ETDEWEB)

    Baughcum, S.L.; Henderson, S.C.; Tritz, T.G. [Boeing Co., Seattle, WA (United States)

    1997-12-31

    Emission inventories of fuel burned, NO{sub x}, CO, and hydrocarbons have been calculated for scheduled air traffic in 1976, 1984, 1990 and 1992 on a 1 deg latitude x 1 deg longitude x 1 km pressure altitude grid. Using this database, the seasonal variation and historical trends in aircraft emissions have been calculated for selected geographical regions (e.g., North Atlantic, Europe, North America, North Pacific). The trend in emissions is a combination of the effects of passenger demand growth, improved aircraft efficiency, changes in combustor characteristics, and aircraft size. (author) 8 refs.

  8. Aircraft operations management manual

    Science.gov (United States)

    1992-01-01

    The NASA aircraft operations program is a multifaceted, highly diverse entity that directly supports the agency mission in aeronautical research and development, space science and applications, space flight, astronaut readiness training, and related activities through research and development, program support, and mission management aircraft operations flights. Users of the program are interagency, inter-government, international, and the business community. This manual provides guidelines to establish policy for the management of NASA aircraft resources, aircraft operations, and related matters. This policy is an integral part of and must be followed when establishing field installation policy and procedures covering the management of NASA aircraft operations. Each operating location will develop appropriate local procedures that conform with the requirements of this handbook. This manual should be used in conjunction with other governing instructions, handbooks, and manuals.

  9. Dosimetry of cosmic rays in civil aircraft according to ISO standards

    International Nuclear Information System (INIS)

    Ploc, O.; Sommer, M.; Kakona, M.; Peksova, D.; Slegl, J.

    2018-01-01

    The aim of the paper is to draw attention to the existence of these ISO standards and to show the experiment how they can contribute in practice to improving the dosimetry of aircraft crews. The experiment took place this year on board an ABS jets aircraft flying around the world with a Liulin detector, and the CARI program was used as the validation code. (authors)

  10. High Altitude Clear Air Turbulence Project

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Air Force Flight Dynamics Laboratory conducted the High Altitude Clear Air Turbulence Project in the mid 1960s with the intention of better understanding air...

  11. Bilateral Vestibular Dysfunction Associated With Chronic Exposure to Military Jet Propellant Type-Eight Jet Fuel

    Directory of Open Access Journals (Sweden)

    Terry D. Fife

    2018-05-01

    Full Text Available We describe three patients diagnosed with bilateral vestibular dysfunction associated with the jet propellant type-eight (JP-8 fuel exposure. Chronic exposure to aromatic and aliphatic hydrocarbons, which are the main constituents of JP-8 military aircraft jet fuel, occurred over 3–5 years’ duration while working on or near the flight line. Exposure to toxic hydrocarbons was substantiated by the presence of JP-8 metabolite n-hexane in the blood of one of the cases. The presenting symptoms were dizziness, headache, fatigue, and imbalance. Rotational chair testing confirmed bilateral vestibular dysfunction in all the three patients. Vestibular function improved over time once the exposure was removed. Bilateral vestibular dysfunction has been associated with hydrocarbon exposure in humans, but only recently has emphasis been placed specifically on the detrimental effects of JP-8 jet fuel and its numerous hydrocarbon constituents. Data are limited on the mechanism of JP-8-induced vestibular dysfunction or ototoxicity. Early recognition of JP-8 toxicity risk, cessation of exposure, and customized vestibular therapy offer the best chance for improved balance. Bilateral vestibular impairment is under-recognized in those chronically exposed to all forms of jet fuel.

  12. Introduction to altitude/hypoxic training symposium.

    Science.gov (United States)

    Wilber, Randall L

    2007-09-01

    Altitude/hypoxic training has traditionally been an intriguing and controversial area of research and sport performance. This controversial aspect was evident recently in the form of scholarly debates in highly regarded professional journals, as well as the World Anti-Doping Agency's (WADA) consideration of placing "artificially-induced hypoxic conditions" on the 2007 Prohibited List of Substances/Methods. In light of the ongoing controversy surrounding altitude/hypoxic training, this symposium was organized with the following objectives in mind: 1) to examine the primary physiological responses and underlying mechanisms associated with altitude/hypoxic training, including the influence of genetic predisposition; 2) to present evidence supporting the effect of altitude/hypoxic acclimatization on both hematological and nonhematological markers, including erythrocyte volume, skeletal muscle-buffering capacity, hypoxic ventilatory response, and physiological efficiency/economy; 3) to evaluate the efficacy of several contemporary simulated altitude modalities and training strategies, including hypoxic tents, nitrogen apartments, and intermittent hypoxic exposure (IHE) or training, and to address the legal and ethical issues associated with the use of simulated altitude; and 4) to describe different altitude/hypoxic training strategies used by elite-level athletes, including Olympians and military special forces. In addressing these objectives, papers will be presented on the topics of: 1) effect of hypoxic "dose" on physiological responses and sea-level performance (Drs. Benjamin Levine and James Stray-Gundersen), 2) nonhematological mechanisms of improved performance after hypoxic exposure (Dr. Christopher Gore), 3) application of altitude/hypoxic training by elite athletes (Dr. Randall Wilber), and 4) military applications of hypoxic training (Dr. Stephen Muza).

  13. Jets and QCD

    International Nuclear Information System (INIS)

    Ali, A.; Kramer, G.

    2010-12-01

    The observation of quark and gluon jets has played a crucial role in establishing Quantum Chromodynamics [QCD] as the theory of the strong interactions within the Standard Model of particle physics. The jets, narrowly collimated bundles of hadrons, reflect configurations of quarks and gluons at short distances. Thus, by analysing energy and angular distributions of the jets experimentally, the properties of the basic constituents of matter and the strong forces acting between them can be explored. In this review we summarise the properties of quark and gluon jets and the impact of their observation on Quantum Chromodynamics, primarily the discovery of the gluons as the carriers of the strong force. Focusing on these basic points, jets in e + e - collisions will be in the foreground of the discussion. In addition we will delineate the role of jets as tools for exploring other particle aspects in ep and pp/p anti p collisions - quark and gluon densities in protons, measurements of the QCD coupling, fundamental 2-2 quark/gluon scattering processes, but also the impact of jet decays of top quarks, and W ± ,Z bosons on the electroweak sector. The presentation to a large extent is formulated in a non-technical language with the intent to recall the significant steps historically and convey the significance of this field also to communities beyond high energy physics. (orig.)

  14. Jets and QCD

    Energy Technology Data Exchange (ETDEWEB)

    Ali, A. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Kramer, G. [Hamburg Univ. (Germany). II. Inst. fuer Theoretische Physik

    2010-12-15

    The observation of quark and gluon jets has played a crucial role in establishing Quantum Chromodynamics [QCD] as the theory of the strong interactions within the Standard Model of particle physics. The jets, narrowly collimated bundles of hadrons, reflect configurations of quarks and gluons at short distances. Thus, by analysing energy and angular distributions of the jets experimentally, the properties of the basic constituents of matter and the strong forces acting between them can be explored. In this review we summarise the properties of quark and gluon jets and the impact of their observation on Quantum Chromodynamics, primarily the discovery of the gluons as the carriers of the strong force. Focusing on these basic points, jets in e{sup +}e{sup -} collisions will be in the foreground of the discussion. In addition we will delineate the role of jets as tools for exploring other particle aspects in ep and pp/p anti p collisions - quark and gluon densities in protons, measurements of the QCD coupling, fundamental 2-2 quark/gluon scattering processes, but also the impact of jet decays of top quarks, and W{sup {+-}},Z bosons on the electroweak sector. The presentation to a large extent is formulated in a non-technical language with the intent to recall the significant steps historically and convey the significance of this field also to communities beyond high energy physics. (orig.)

  15. Jet angularity measurements for single inclusive jet production

    Science.gov (United States)

    Kang, Zhong-Bo; Lee, Kyle; Ringer, Felix

    2018-04-01

    We study jet angularity measurements for single-inclusive jet production at the LHC. Jet angularities depend on a continuous parameter a allowing for a smooth interpolation between different traditional jet shape observables. We establish a factorization theorem within Soft Collinear Effective Theory (SCET) where we consistently take into account in- and out-of-jet radiation by making use of semi-inclusive jet functions. For comparison, we elaborate on the differences to jet angularities measured on an exclusive jet sample. All the necessary ingredients for the resummation at next-to-leading logarithmic (NLL) accuracy are presented within the effective field theory framework. We expect semiinclusive jet angularity measurements to be feasible at the LHC and we present theoretical predictions for the relevant kinematic range. In addition, we investigate the potential impact of jet angularities for quark-gluon discrimination.

  16. Early history of high-altitude physiology.

    Science.gov (United States)

    West, John B

    2016-02-01

    High-altitude physiology can be said to have begun in 1644 when Torricelli described the first mercury barometer and wrote the immortal words "We live submerged at the bottom of an ocean of the element air." Interestingly, the notion of atmospheric pressure had eluded his teacher, the great Galileo. Blaise Pascal was responsible for describing the fall in pressure with increasing altitude, and Otto von Guericke gave a dramatic demonstration of the enormous force that could be developed by atmospheric pressure. Robert Boyle learned of Guericke's experiment and, with Robert Hooke, constructed the first air pump that allowed small animals to be exposed to a low pressure. Hooke also constructed a small low-pressure chamber and exposed himself to a simulated altitude of about 2400 meters. With the advent of ballooning, humans were rapidly exposed to very low pressures, sometimes with tragic results. For example, the French balloon, Zénith, rose to over 8000 m, and two of the three aeronauts succumbed to the hypoxia. Paul Bert was the first person to clearly state that the deleterious effects of high altitude were caused by the low partial pressure of oxygen (PO2), and later research was accelerated by high-altitude stations and expeditions to high altitude. © 2015 New York Academy of Sciences.

  17. Application of Time-resolved PIV to Supersonic Hot Jets

    Science.gov (United States)

    Bridges, James; Wernet, Mark P.

    2007-01-01

    This presentation lays out the ground-breaking work at bringing high-speed (25kHz) particle image velocimetry (PIV) to bear on measurements of noise-producing turbulence in hot jets. The work is still in progress in that the tremendous amount of data obtained are still be analyzed, but the method has been validated and initial results of interest to jet noise modeling have been obtained. After a brief demonstration of the validation process used on the data, results are shown for hot jets at different temperatures and Mach numbers. Comparisons of first order statistics show the relative indifference of the turbulence to the presence of shocks and independence to jet temperature. What does come out is that when the shock-containing jets are in a screech mode the turbulence is highly elevated, showing the importance of removing screech phenomena from model-scale jets before applying findings to full-scale aircraft which typically do not contain shocks.

  18. Intermediate PT jet spectrometers

    International Nuclear Information System (INIS)

    Gutay, L.J.; Koltick, D.; Hauptman, J.; Stork, D.; Theodosiou, G.

    1988-01-01

    A design is presented for a limited solid angle, high resolution double arm spectrometer at 90 degree to the begin, with a vertex detector and particle identification in both arms. The jet arm is designed to accept a complete jet, and identify its substructure of sub-jets, hadrons, and leptons. The particle arm would measure e,π,K,p ratios for P T 0 to the beam for the purpose of tagging Higgs production by boson fusion, 1 gauge boson (WW, ZZ, and WZ) scattering 2 L, and other processes involving the interactions of virtual gauge bosons

  19. Latest results from JET

    International Nuclear Information System (INIS)

    Bickerton, R.J.

    1989-01-01

    The Joint European Torus (JET) is a large tokamak designed with the essential objective of obtaining and studying plasmas with parameters close to those envisaged for an eventual power-generating, nuclear-fusion reactor. JET is situated on a site near Abingdon, Oxon, UK. JET is the largest single project of the nuclear fusion research programme of the European Atomic Energy Community (EURATOM). The tokamak started operation in mid 1983 after a five year construction period. The scientific and technical results achieved so far are summarised in this article. (orig.)

  20. Oscillating acoustic streaming jet

    International Nuclear Information System (INIS)

    Moudjed, Brahim; Botton, Valery; Henry, Daniel; Millet, Severine; Ben Hadid, Hamda; Garandet, Jean-Paul

    2014-01-01

    The present paper provides the first experimental investigation of an oscillating acoustic streaming jet. The observations are performed in the far field of a 2 MHz circular plane ultrasound transducer introduced in a rectangular cavity filled with water. Measurements are made by Particle Image Velocimetry (PIV) in horizontal and vertical planes near the end of the cavity. Oscillations of the jet appear in this zone, for a sufficiently high Reynolds number, as an intermittent phenomenon on an otherwise straight jet fluctuating in intensity. The observed perturbation pattern is similar to that of former theoretical studies. This intermittently oscillatory behavior is the first step to the transition to turbulence. (authors)

  1. Cleanup of a jet fuel spill

    Science.gov (United States)

    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.

  2. [Physiological aspects of altitude training and the use of altitude simulators].

    Science.gov (United States)

    Ranković, Goran; Radovanović, Dragan

    2005-01-01

    Altitude training in various forms is widely practiced by athletes and coaches in an attempt to improve sea level endurance. Training at high altitude may improve performance at sea level through altitude acclimatisation, which improves oxygen transport and/or utilisation, or through hypoxia, which intensifies the training stimulus. This basic physiological aspect allows three training modalities: live high and train high (classic high-altitude training), live low and train high (training through hypoxia), and live high and train low (the new trend). In an effort to reduce the financial and logistical challenges of travelling to high-altitude training sites, scientists and manufactures have developed artificial high-altitude environments, which simulate the hypoxic conditions of moderate altitude (2000-3000 meters). Endurance athletes from many sports have recently started using nitrogen environments, or hypoxic rooms and tents as part of their altitude training programmes. The results of controlled studies on these modalities of high-altitude training, their practical approach, and ethics are summarised.

  3. Physiological aspects of altitude training and the use of altitude simulators

    Directory of Open Access Journals (Sweden)

    Ranković Goran

    2005-01-01

    Full Text Available Altitude training in various forms is widely practiced by athletes and coaches in an attempt to improve sea level endurance. Training at high altitude may improve performance at sea level through altitude acclimatization, which improves oxygen transport and/or utilization, or through hypoxia, which intensifies the training stimulus. This basic physiological aspect allows three training modalities: live high and train high (classic high-altitude training, live low and train high (training through hypoxia, and live high and train low (the new trend. In an effort to reduce the financial and logistical challenges of traveling to high-altitude training sites, scientists and manufactures have developed artificial high-altitude environments, which simulate the hypoxic conditions of moderate altitude (2000-3000 meters. Endurance athletes from many sports have recently started using nitrogen environments, or hypoxic rooms and tents as part of their altitude training programmes. The results of controlled studies on these modalities of high-altitude training, their practical approach, and ethics are summarized.

  4. Predicting visibility of aircraft.

    Directory of Open Access Journals (Sweden)

    Andrew Watson

    Full Text Available Visual detection of aircraft by human observers is an important element of aviation safety. To assess and ensure safety, it would be useful to be able to be able to predict the visibility, to a human observer, of an aircraft of specified size, shape, distance, and coloration. Examples include assuring safe separation among aircraft and between aircraft and unmanned vehicles, design of airport control towers, and efforts to enhance or suppress the visibility of military and rescue vehicles. We have recently developed a simple metric of pattern visibility, the Spatial Standard Observer (SSO. In this report we examine whether the SSO can predict visibility of simulated aircraft images. We constructed a set of aircraft images from three-dimensional computer graphic models, and measured the luminance contrast threshold for each image from three human observers. The data were well predicted by the SSO. Finally, we show how to use the SSO to predict visibility range for aircraft of arbitrary size, shape, distance, and coloration.

  5. Ooishi's Observation: Viewed in the Context of Jet Stream Discovery.

    Science.gov (United States)

    Lewis, John M.

    2003-03-01

    Although aircraft encounters with strong westerly winds during World War II provided the stimulus for postwar research on the jet stream, Wasaburo Ooishi observed these winds in the 1920s. Ooishi's work is reviewed in the context of earlier work in upperair observation and postwar work on the jet stream. An effort is made to reconstruct Ooishi's path to the directorship of Japan's first upper-air observatory by reliance on historical studies and memoirs from the Central Meteorological Observatory.Archival records from Japan's Aerological Observatory have been used to document Ooishi's upperair observations. The first official report from the observatory (written in 1926 and in the auxiliary language of Esperanto) assumes a central role in the study. In this report, data are stratified by season and used to produce the mean seasonal wind profiles. The profile for winter gives the first known evidence of the persistent strong westerlies over Japan that would later become known as the jet stream.

  6. Thrust and jet directional control using the Coanda effect

    Directory of Open Access Journals (Sweden)

    Alexandru DUMITRACHE

    2018-06-01

    Full Text Available The application of the Coandă effect to the directional control of a jet or thrust is presented. Deviation of the thrust force by direct flow can be achieved by using the Coandă effect to change the angle of the primary jet engine exhaust nozzle. Major interest in the study of this phenomenon is caused by the possibility of using this effect for aircrafts with short take-off and landing, for thrust vectoring. The numerical investigations are performed using a RANS solver with an adequate turbulence model, showing a change of the jet direction. Thus, the conditions and the limits within which one can benefit from the advantages of Coandă-type flows are determined.

  7. Gas dynamics, optics and chemistry of an aircraft condensable wake

    Energy Technology Data Exchange (ETDEWEB)

    Grinats, E.S.; Kashevarov, A.V.; Stasenko, A.L. [Central Aerohydrodynamic Inst., Zhukovsky (Russian Federation)

    1997-12-31

    Prediction of the properties of a jet-and-vortex wake from an individual airplane is of great interest as the first step to assessment of the possible global changes in the atmosphere due to the world civil aviation. Several mathematical models of the different regions of an aircraft wake and corresponding numerical results are presented. The axisymmetric exhaust jet was simulated on the base of the well-known k-{epsilon} model of turbulence. Jet chemistry was investigated on the base of kinetic scheme of the gas phase reactions of enriched by including chemisorption by water droplets of several species and by taking into account of the photochemical processes. In the 3D far wake model, the numerical results for distribution of species exhausted by the engines and entrapped by the velocity field of two parallel vortices are shown. (R.P.) 7 refs.

  8. Gas dynamics, optics and chemistry of an aircraft condensable wake

    Energy Technology Data Exchange (ETDEWEB)

    Grinats, E S; Kashevarov, A V; Stasenko, A L [Central Aerohydrodynamic Inst., Zhukovsky (Russian Federation)

    1998-12-31

    Prediction of the properties of a jet-and-vortex wake from an individual airplane is of great interest as the first step to assessment of the possible global changes in the atmosphere due to the world civil aviation. Several mathematical models of the different regions of an aircraft wake and corresponding numerical results are presented. The axisymmetric exhaust jet was simulated on the base of the well-known k-{epsilon} model of turbulence. Jet chemistry was investigated on the base of kinetic scheme of the gas phase reactions of enriched by including chemisorption by water droplets of several species and by taking into account of the photochemical processes. In the 3D far wake model, the numerical results for distribution of species exhausted by the engines and entrapped by the velocity field of two parallel vortices are shown. (R.P.) 7 refs.

  9. SOLAR AIRCRAFT DESIGN

    OpenAIRE

    RAHMATI, Sadegh; GHASED, Amir

    2015-01-01

    Abstract. Generally domain Aircraft uses conventional fuel. These fuel having limited life, high cost and pollutant. Also nowadays price of petrol and other fuels are going to be higher, because of scarcity of those fuels. So there is great demand of use of non-exhaustible unlimited source of energy like solar energy. Solar aircraft is one of the ways to utilize solar energy. Solar aircraft uses solar panel to collect the solar radiation for immediate use but it also store the remaining part ...

  10. Submaximal Exercise and Cognitive Function Testing at Altitude to Determine the Impact of Different Levels of Hypobaric Hypoxia

    Science.gov (United States)

    1997-01-01

    would exercise and two who were controls). The control included either playing bingo or remaining inactive. The tests were administered again after...15 added benefits may be outweighed by muscle fatigue (Tomporowski & Ellis, 1986). Altitude and Exercise Performance The interplay among hypoxia...an inevitable part of aviation. With the benefits and convenience of ascending into the sky 35 in an aircraft, come the risks of operating in what

  11. Neutron-induced single event upsets in static RAMS observed at 10 km flight altitude

    International Nuclear Information System (INIS)

    Olsen, J.; Becher, P.E.; Fynbo, P.B.; Raaby, P. Schultz, J.

    1993-01-01

    Neutron induced single event upsets (SEUs) in static memory devices (SRAMs) have so far been seen only in laboratory environments. The authors report observations of 14 neutron induced SEUs at commercial aircraft flight altitudes as well. The observed SEU rate at 10 km flight altitude based on exposure of 160 standard 256 Kbit CMOS SRAMs is 4.8 · 10 -8 upsets/bit/day. In the laboratory 117 SRAMs of two different brands were irradiated with fast neutrons from a Pu-Be source. A total of 176 SEUs have been observed, among these are two SEU pairs. The upset rates from the laboratory tests are compared to those found in the airborne SRAMS

  12. Cosmic radiation dose in the aircraft

    International Nuclear Information System (INIS)

    Vukovic, B.; Radolic, V.; Varga, M.; Planinic, J.; Vekic, B.

    2006-01-01

    When primary particles from space, mainly protons, enter the atmosphere, they produce interactions with air nuclei, and cosmic-ray showers are induced. The radiation field at aircraft altitude is complex, with different types of particles, mainly photons, electrons, positrons and neutrons, with a large energy range. The non-neutron component of cosmic radiation dose aboard A 320 and ATR 42 aircraft was measured with TLD-100 (LiF:Mg,Ti) detectors and the Mini 6100 semiconductor dosimeter; the neutron dose was measured with the neutron dosimeter consisted of LR-115 track detector and boron foil BN-1 or 10B converter. The estimated occupational effective dose for the aircraft crew (A320) working 500 h per year was 1.64 mSv. Another experiment was performed at the flights Zagreb - Paris - Buenos Aires and reversely, when one measured cosmic radiation dose; for 26.7 h of flight, the MINI 6100 dosimeter gave an average dose rate of 2.3 μSv/h and the TLD dosimeter registered the total dose of 75 μSv or the average dose rate of 2.7 μSv/h; the neutron dosimeter gave the dose rate of 2.4 μSv/h. In the same month, February 2005, a traveling to the Japan (24 hours-flight: Zagreb - Frankfurt - Tokyo and reversely) and the TLD-100 measurement showed the average dose rate of 2.4 μSv/h; the neutron dosimeter gave the dose rate of 2.5 μSv/h. Comparing dose rates of the non-neutron component (low LET) and the neutron one (high LET) of the radiation field at the aircraft flight level, we could conclude the neutron component curried about 50% of the total dose, that was near other known data. (author)

  13. Measurements of Jets in ALICE

    CERN Document Server

    Nattrass, Christine

    2016-01-01

    The ALICE detector can be used for measurements of jets in pp , p Pb, and Pb–Pb collisions. Measurements of jets in pp collisions are consis- tent with expectations from perturbative calculations and jets in p Pb scale with the number of nucleon–nucleon collisions, indicating that cold nuclear matter effects are not observed for jets. Measurements in Pb–Pb collisions demonstrate suppression of jets relative to expectations from binary scaling to the equivalent number of nucleon–nucleon collisions

  14. Jet lag prevention

    Science.gov (United States)

    ... lose time. Symptoms of jet lag include: Trouble falling asleep or waking up Tiredness during the day ... at your destination. For longer trips, before you leave, try to adapt to the time schedule of ...

  15. Intermonsoonal equatorial jets

    Digital Repository Service at National Institute of Oceanography (India)

    Muraleedharan, P.M.

    , respectively. Hydrographic features and transport computations favour a well developed equatorial jet during both seasons. The net surface eastward and subsurface westward flows are well balanced during the premonsoon transition period and appear...

  16. Detection Damage in Bearing System of Jet Engine Using the Vibroacoustic Method

    Directory of Open Access Journals (Sweden)

    Żokowski Mariusz

    2017-09-01

    Full Text Available The article discusses typical, operational systems for monitoring vibrations of jet engines, which constitute the propulsion of combat aircraft of the Armed Forces of the Republic of Poland. After that, the paper presents the stage of installing vibration measuring sensors in the direct area of one of the jet engine bearings, which is a support system for its rotor. The article discusses results of carried out analyses of data gathered during tests of the engine in the conditions a jet engine test bed. Results of detecting damages to the bear-ing, using sensors built in the direct area will be presented.

  17. The JET divertor coil

    International Nuclear Information System (INIS)

    Last, J.R.; Froger, C.; Sborchia, C.

    1989-01-01

    The divertor coil is mounted inside the Jet vacuum vessel and is able to carry 1 MA turns. It is of conventional construction - water cooled copper, epoxy glass insulation -and is contained in a thin stainless steel case. The coil has to be assembled, insulated and encased inside the Jet vacuum vessel. A description of the coil is given, together with technical information (including mechanical effects on the vacuum vessel), an outline of the manufacture process and a time schedule. (author)

  18. Pellet injectors for JET

    International Nuclear Information System (INIS)

    Andelfinger, C.; Buechl, K.; Lang, R.S.; Schilling, H.B.; Ulrich, M.

    1981-09-01

    Pellet injection for the purpose of refuelling and diagnostic of fusion experiments is considered for the parameters of JET. The feasibility of injectors for single pellets and for quasistationary refuelling is discussed. Model calculations on pellet ablation with JET parameters show the required pellet velocity ( 3 ). For single pellet injection a light gas gun, for refuelling a centrifuge accelerator is proposed. For the latter the mechanical stress problems are discussed. Control and data acquisition systems are outlined. (orig.)

  19. PIV Measurements of Supersonic Internally-Mixed Dual-Stream Jets

    Science.gov (United States)

    Bridges, James E.; Wernet, Mark P.

    2012-01-01

    While externally mixed, or separate flow, nozzle systems are most common in high bypass-ratio aircraft, they are not as attractive for use in lower bypass-ratio systems and on aircraft that will fly supersonically. The noise of such propulsion systems is also dominated by jet noise, making the study and noise reduction of these exhaust systems very important, both for military aircraft and future civilian supersonic aircraft. This paper presents particle image velocimetry of internally mixed nozzle with different area ratios between core and bypass, and nozzles that are ideally expanded and convergent. Such configurations independently control the geometry of the internal mixing layer and of the external shock structure. These allow exploration of the impact of shocks on the turbulent mixing layers, the impact of bypass ratio on broadband shock noise and mixing noise, and the impact of temperature on the turbulent flow field. At the 2009 AIAA/CEAS Aeroacoustics Conference the authors presented data and analysis from a series of tests that looked at the acoustics of supersonic jets from internally mixed nozzles. In that paper the broadband shock and mixing noise components of the jet noise were independently manipulated by holding Mach number constant while varying bypass ratio and jet temperature. Significant portions of that analysis was predicated on assumptions regarding the flow fields of these jets, both shock structure and turbulence. In this paper we add to that analysis by presenting particle image velocimetry measurements of the flow fields of many of those jets. In addition, the turbulent velocity data documented here will be very useful for validation of computational flow codes that are being developed to design advanced nozzles for future aircraft.

  20. High Altitude Emissions of Black Carbon Aerosols: Potential Climate Implications

    Science.gov (United States)

    Satheesh, S. K.

    2017-12-01

    Synthesizing a series of ground-based and airborne measurements of aerosols over the Indian region during summer and pre-monsoon seasons have revealed the persistence of elevated absorbing aerosol layers over most of the Indian region; more than 50% of which located above clouds. Subsequent, in situ measurements of black carbon (BC) using high-altitude balloons, showed surprising layers with high concentrations in the middle and upper troposphere even at an altitude of 8 to 10 kms. Simultaneous measurements of the vertical thermal structure have shown localized warming due to BC absorption leading to large reduction in lapse rate and sharp temperature inversion, which in turn increases the atmospheric stability. This aerosol-induced stable layer is conducive for maintaining the black carbon layer longer at that level, leading thereby to further solar absorption and subsequently triggering dry convection. These observations support the `solar escalator' concept through which absorption-warming-convection cycles lead to self-lifting of BC to upper troposphere or even to lower stratosphere under favorable conditions in a matter of a few days. Employing an on-line regional chemistry transport model (WRF-Chem), incorporating aircraft emissions, it is shown that emissions from high-flying aircrafts as the most likely source of these elevated black carbon layers. These in-situ injected particles, produce significant warming of the thin air in those heights and lift these layers to even upper tropospheric/lower stratospheric heights, aided by the strong monsoonal convection occurring over the region, which are known to overshoot the tropical tropopause leading to injection of tropospheric air mass (along with its constituent aerosols) into the stratosphere, especially during monsoon season when the tropical tropopause layer is known to be thinnest. These simulations are further supported by the CALIPSO space-borne LIDAR derived extinction coefficient profiles. Based on

  1. New capability for ozone dial profiling measurements in the troposphere and lower stratosphere from aircraft

    Science.gov (United States)

    Hair, Johnathan; Hostetler, Chris; Cook, Anthony; Harper, David; Notari, Anthony; Fenn, Marta; Newchurch, Mike; Wang, Lihua; Kuang, Shi; Knepp, Travis; Burton, Sharon; Ferrare, Richard; Butler, Carolyn; Collins, Jim; Nehrir, Amin

    2018-04-01

    Recently, we successfully demonstrated a new compact and robust ozone DIAL lidar for smaller aircraft such as the NASA B200 and the ER-2 high-altitude aircraft. This is the first NASA airborne lidar to incorporate advanced solid-state lasers to produce the required power at the required ultraviolet wavelengths, and is compact and robust enough to operate nearly autonomously on the high-altitude ER-2 aircraft. This technology development resulted in the first new NASA airborne ozone DIAL instrument in more than 15 years. The combined ozone, aerosol, and clouds measurements provide valuable information on the chemistry, radiation, and dynamics of the atmosphere. In particular, from the ER-2 it offers a unique capability to study the upper troposphere and lower stratosphere.

  2. New capability for ozone dial profiling measurements in the troposphere and lower stratosphere from aircraft

    Directory of Open Access Journals (Sweden)

    Hair Johnathan

    2018-01-01

    Full Text Available Recently, we successfully demonstrated a new compact and robust ozone DIAL lidar for smaller aircraft such as the NASA B200 and the ER-2 high-altitude aircraft. This is the first NASA airborne lidar to incorporate advanced solid-state lasers to produce the required power at the required ultraviolet wavelengths, and is compact and robust enough to operate nearly autonomously on the high-altitude ER-2 aircraft. This technology development resulted in the first new NASA airborne ozone DIAL instrument in more than 15 years. The combined ozone, aerosol, and clouds measurements provide valuable information on the chemistry, radiation, and dynamics of the atmosphere. In particular, from the ER-2 it offers a unique capability to study the upper troposphere and lower stratosphere.

  3. Protostellar Jets in Context

    CERN Document Server

    Tsinganos, Kanaris; Stute, Matthias

    2009-01-01

    This volume contains the proceedings of the Conference Protostellar Jets in Context held by the JETSET Marie Curie Research Training Network in July 2008. This meeting not only served to showcase some of the network's achievements but was also a platform to hear from, discuss and debate the recent findings of world-class astrophysicists in the field of protostellar jet research. Jets from young stars are of course not an isolated astrophysical phenomenon. It is known that objects as diverse as young brown dwarfs, planetary nebulae, symbiotic stars, micro-quasars, AGN, and gamma-ray bursters produce jets. Thus in a series of talks, protostellar jets were put in context by comparing them with their often much larger brethren and also by considering the ubiquitous accretion disks that seem to be necessary for their formation. With this spectrum of contributions on observations and the theory of astrophysical jets and accretion disks, this book serves as a comprehensive reference work for researchers and students...

  4. Acute high-altitude illness | Hofmeyr | South African Medical Journal

    African Journals Online (AJOL)

    A substantial proportion of South Africa (SA)'s population lives at high altitude (>1 500 m), and many travel to very high altitudes (>3 500 m) for tourism, business, recreation or religious pilgrimages every year. Despite this, knowledge of acute altitude illnesses is poor among SA doctors. At altitude, the decreasing ambient ...

  5. Jet supercooling and molecular jet spectroscopy

    International Nuclear Information System (INIS)

    Wharton, L.; Levy, D.

    1979-01-01

    The marriage of the laser and the seeded supersonic jet has generated a family of new optical spectroscopic results. We shall discuss the essential features of the technique and some results. The results will include structural and dynamical views of NO 2 , NaAr, and I 2 -noble gas complexes. The extension of the method to heavier systems is illustrated with free base phthalocyanine

  6. Configuration management and automatic control of an augmentor wing aircraft with vectored thrust

    Science.gov (United States)

    Cicolani, L. S.; Sridhar, B.; Meyer, G.

    1979-01-01

    An advanced structure for automatic flight control logic for powered-lift aircraft operating in terminal areas is under investigation at Ames Research Center. This structure is based on acceleration control; acceleration commands are constructed as the sum of acceleration on the reference trajectory and a corrective feedback acceleration to regulate path tracking errors. The central element of the structure, termed a Trimmap, uses a model of the aircraft aerodynamic and engine forces to calculate the control settings required to generate the acceleration commands. This report describes the design criteria for the Trimmap and derives a Trimmap for Ames experimental augmentor wing jet STOL research aircraft.

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

    Science.gov (United States)

    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.

  8. Aircraft Fire Protection Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Navy Aircraft Protection Laboratory provides complete test support for all Navy air vehicle fire protection systems.The facility allows for the simulation of a...

  9. Automated Inspection of Aircraft

    Science.gov (United States)

    1998-04-01

    This report summarizes the development of a robotic system designed to assist aircraft inspectors by remotely deploying non-destructive inspection (NDI) sensors and acquiring, processing, and storing inspection data. Carnegie Mellon University studie...

  10. Aircraft Depainting Technology

    National Research Council Canada - National Science Library

    Kozol, Joseph

    1999-01-01

    ... of aircraft and component stripping at various levels of maintenance. Under this program, the Navy pursued development of non-HAP chemical paint strippers as alternatives for methylene chloride based strippers...

  11. The Aircraft Industry, 2006

    National Research Council Canada - National Science Library

    Daniel, Keith

    2006-01-01

    .... and global economic growth. The overall outlook for the industry is positive. Orders for commercial aircraft are up from a boom in air travel that is likely to continue well into the next decade...

  12. Essentials of aircraft armaments

    CERN Document Server

    Kaushik, Mrinal

    2017-01-01

    This book aims to provide a complete exposure about armaments from their design to launch from the combat aircraft. The book details modern ammunition and their tactical roles in warfare. The proposed book discusses aerodynamics, propulsion, structural as well as navigation, control, and guidance of aircraft armament. It also introduces the various types of ammunition developed by different countries and their changing trends. The book imparts knowledge in the field of design, and development of aircraft armaments to aerospace engineers and covers the role of the United Nations in peacekeeping and disarmament. The book will be very useful to researchers, students, and professionals working in design and manufacturing of aircraft armaments. The book will also serve air force and naval aspirants, and those interested in working on defence research and developments organizations. .

  13. Solar thermal aircraft

    Science.gov (United States)

    Bennett, Charles L.

    2007-09-18

    A solar thermal powered aircraft powered by heat energy from the sun. A heat engine, such as a Stirling engine, is carried by the aircraft body for producing power for a propulsion mechanism, such as a propeller. The heat engine has a thermal battery in thermal contact with it so that heat is supplied from the thermal battery. A solar concentrator, such as reflective parabolic trough, is movably connected to an optically transparent section of the aircraft body for receiving and concentrating solar energy from within the aircraft. Concentrated solar energy is collected by a heat collection and transport conduit, and heat transported to the thermal battery. A solar tracker includes a heliostat for determining optimal alignment with the sun, and a drive motor actuating the solar concentrator into optimal alignment with the sun based on a determination by the heliostat.

  14. The Aircraft Morphing Program

    Science.gov (United States)

    Wlezien, R. W.; Horner, G. C.; McGowan, A. R.; Padula, S. L.; Scott, M. A.; Silcox, R. J.; Simpson, J. O.

    1998-01-01

    In the last decade smart technologies have become enablers that cut across traditional boundaries in materials science and engineering. Here we define smart to mean embedded actuation, sensing, and control logic in a tightly coupled feedback loop. While multiple successes have been achieved in the laboratory, we have yet to see the general applicability of smart devices to real aircraft systems. The NASA Aircraft Morphing program is an attempt to couple research across a wide range of disciplines to integrate smart technologies into high payoff aircraft applications. The program bridges research in seven individual disciplines and combines the effort into activities in three primary program thrusts. System studies are used to assess the highest- payoff program objectives, and specific research activities are defined to address the technologies required for development of smart aircraft systems. In this paper we address the overall program goals and programmatic structure, and discuss the challenges associated with bringing the technologies to fruition.

  15. Depreciation of aircraft

    Science.gov (United States)

    Warner, Edward P

    1922-01-01

    There is a widespread, and quite erroneous, impression to the effect that aircraft are essentially fragile and deteriorate with great rapidity when in service, so that the depreciation charges to be allowed on commercial or private operation are necessarily high.

  16. Splenic infarction at low altitude in a child with hemoglobin S-C disease.

    Science.gov (United States)

    Alvarado, C S; Wyly, B; Buchanan, I; Fajman, W A

    1988-08-01

    We describe a 15-year-old black boy with hemoglobin S-C disease living in Atlanta (altitude 1,034 ft), with no prior history of aircraft or mountain travel, who developed splenic infarction. The clinical picture was characterized by severe left upper quadrant abdominal pain, fever, splenomegaly, and hematologic and scintigraphic evidence of functional asplenia. The diagnosis was suggested by liver/spleen scintigraphy and further confirmed by ultrasonography and computerized tomography (CT) of the spleen. Treatment consisted of analgesics, intravenous fluids, and short-term antibiotic therapy. The child recovered without sequelae.

  17. A computational study of the impingement region of an unsteady subsonic jet

    Science.gov (United States)

    Jalamani, Zakaria A.; Nakamura, Shoichiro; Van Dalsem, William R.

    1990-01-01

    Vertical/Short Take-Off and Landing (V/STOL) aircraft may encounter operating difficulties while hovering near the ground. Lift loss, hot gas and debris ingestion, and landing surface damage are some of the potential problems which can result from the interaction of the propulsive jets with the airframe and ground. The purpose of the present work is to develop a detailed understanding of a flowfield, a jet exiting from a flat plate impacting a ground plane, that contains much of the essential physics of the complex flows encountered by V/STOL aircraft in hover. To achieve this, a high-resolution time-accurate numerical simulation of the impinging jet flow was performed. The numerical simulation is based on the solution of the laminar compressible Navier-Stokes equations using the Beam-Warming algorithm. Complex start-up and periodic jet and jet-induced vortex structures were captured, including the formation of primary and secondary jet-induced vortices and wall-jet separation. The formation and development of these phenomena are supported by experimental measurements and smoke visualization. Results are compared with appropriate experiments.

  18. Reduction environmental effects of civil aircraft through multi-objective flight plan optimisation

    International Nuclear Information System (INIS)

    Lee, D S; Gonzalez, L F; Walker, R; Periaux, J; Onate, E

    2010-01-01

    With rising environmental alarm, the reduction of critical aircraft emissions including carbon dioxides (CO 2 ) and nitrogen oxides (NO x ) is one of most important aeronautical problems. There can be many possible attempts to solve such problem by designing new wing/aircraft shape, new efficient engine, etc. The paper rather provides a set of acceptable flight plans as a first step besides replacing current aircrafts. The paper investigates a green aircraft design optimisation in terms of aircraft range, mission fuel weight (CO 2 ) and NO x using advanced Evolutionary Algorithms coupled to flight optimisation system software. Two multi-objective design optimisations are conducted to find the best set of flight plans for current aircrafts considering discretised altitude and Mach numbers without designing aircraft shape and engine types. The objectives of first optimisation are to maximise range of aircraft while minimising NO x with constant mission fuel weight. The second optimisation considers minimisation of mission fuel weight and NO x with fixed aircraft range. Numerical results show that the method is able to capture a set of useful trade-offs that reduce NO x and CO 2 (minimum mission fuel weight).

  19. Multifuel rotary aircraft engine

    Science.gov (United States)

    Jones, C.; Berkowitz, M.

    1980-01-01

    The broad objectives of this paper are the following: (1) to summarize the Curtiss-Wright design, development and field testing background in the area of rotary aircraft engines; (2) to briefly summarize past activity and update development work in the area of stratified charge rotary combustion engines; and (3) to discuss the development of a high-performance direct injected unthrottled stratified charge rotary combustion aircraft engine. Efficiency improvements through turbocharging are also discussed.

  20. 2002 Industry Studies: Aircraft

    Science.gov (United States)

    2002-01-01

    aircraft to a defense electronics, systems integration and information technology company.39 Northrop Grumman no longer seeks a position as a prime...between the military and civil market . Though also upgrading the H-1 helicopter series for the USMC, Bell has mortgaged its future on tiltrotor technology ...business in export dollars, the industry has been forced to look for new markets as worldwide aircraft sales have dropped. Because the U.S. national

  1. Effects of external boundary layer flow on jet noise in flight

    Science.gov (United States)

    Sarohia, V.; Massier, P. F.

    1976-01-01

    The effects on jet flow of the external boundary layer flow emanating from the trailing edge of an engine cowl in flight has been shown to be the main reason for the disparity between predicted and experimental results obtained from flight measurements. Flight simulation experiments indicate that the external boundary layer flow tends to shield the jet flow in flight. This in turn modifies the jet noise source in flight and consequently the radiated noise from aircraft in flight. Close to 90 deg angle to the intake and in the forward quadrant, this study indicates that the far field jet noise and its spectrum scales approximately with the absolute jet velocity instead of the relative velocity as has been assumed in the existing prediction models.

  2. Numerical modeling of normal turbulent plane jet impingement on solid wall

    Energy Technology Data Exchange (ETDEWEB)

    Guo, C.Y.; Maxwell, W.H.C.

    1984-10-01

    Attention is given to a numerical turbulence model for the impingement of a well developed normal plane jet on a solid wall, by means of which it is possible to express different jet impingement geometries in terms of different boundary conditions. Examples of these jets include those issuing from VTOL aircraft, chemical combustors, etc. The two-equation, turbulent kinetic energy-turbulent dissipation rate model is combined with the continuity equation and the transport equation of vorticity, using an iterative finite difference technique in the computations. Peak levels of turbulent kinetic energy occur not only in the impingement zone, but also in the intermingling zone between the edges of the free jet and the wall jet. 20 references.

  3. Can High Altitude Influence Cytokines and Sleep?

    Directory of Open Access Journals (Sweden)

    Valdir de Aquino Lemos

    2013-01-01

    Full Text Available The number of persons who relocate to regions of high altitude for work, pleasure, sport, or residence increases every year. It is known that the reduced supply of oxygen (O2 induced by acute or chronic increases in altitude stimulates the body to adapt to new metabolic challenges imposed by hypoxia. Sleep can suffer partial fragmentation because of the exposure to high altitudes, and these changes have been described as one of the responsible factors for the many consequences at high altitudes. We conducted a review of the literature during the period from 1987 to 2012. This work explored the relationships among inflammation, hypoxia and sleep in the period of adaptation and examined a novel mechanism that might explain the harmful effects of altitude on sleep, involving increased Interleukin-1 beta (IL-1β, Interleukin-6 (IL-6, and tumor necrosis factor-alpha (TNF-α production from several tissues and cells, such as leukocytes and cells from skeletal muscle and brain.

  4. Can High Altitude Influence Cytokines and Sleep?

    Science.gov (United States)

    de Aquino Lemos, Valdir; dos Santos, Ronaldo Vagner Thomatieli; Lira, Fabio Santos; Rodrigues, Bruno; Tufik, Sergio; de Mello, Marco Tulio

    2013-01-01

    The number of persons who relocate to regions of high altitude for work, pleasure, sport, or residence increases every year. It is known that the reduced supply of oxygen (O2) induced by acute or chronic increases in altitude stimulates the body to adapt to new metabolic challenges imposed by hypoxia. Sleep can suffer partial fragmentation because of the exposure to high altitudes, and these changes have been described as one of the responsible factors for the many consequences at high altitudes. We conducted a review of the literature during the period from 1987 to 2012. This work explored the relationships among inflammation, hypoxia and sleep in the period of adaptation and examined a novel mechanism that might explain the harmful effects of altitude on sleep, involving increased Interleukin-1 beta (IL-1β), Interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α) production from several tissues and cells, such as leukocytes and cells from skeletal muscle and brain. PMID:23690660

  5. Altitude Registration of Limb-Scattered Radiation

    Science.gov (United States)

    Moy, Leslie; Bhartia, Pawan K.; Jaross, Glen; Loughman, Robert; Kramarova, Natalya; Chen, Zhong; Taha, Ghassan; Chen, Grace; Xu, Philippe

    2017-01-01

    One of the largest constraints to the retrieval of accurate ozone profiles from UV backscatter limb sounding sensors is altitude registration. Two methods, the Rayleigh scattering attitude sensing (RSAS) and absolute radiance residual method (ARRM), are able to determine altitude registration to the accuracy necessary for long-term ozone monitoring. The methods compare model calculations of radiances to measured radiances and are independent of onboard tracking devices. RSAS determines absolute altitude errors, but, because the method is susceptible to aerosol interference, it is limited to latitudes and time periods with minimal aerosol contamination. ARRM, a new technique introduced in this paper, can be applied across all seasons and altitudes. However, it is only appropriate for relative altitude error estimates. The application of RSAS to Limb Profiler (LP) measurements from the Ozone Mapping and Profiler Suite (OMPS) on board the Suomi NPP (SNPP) satellite indicates tangent height (TH) errors greater than 1 km with an absolute accuracy of +/-200 m. Results using ARRM indicate a approx. 300 to 400m intra-orbital TH change varying seasonally +/-100 m, likely due to either errors in the spacecraft pointing or in the geopotential height (GPH) data that we use in our analysis. ARRM shows a change of approx. 200m over 5 years with a relative accuracy (a long-term accuracy) of 100m outside the polar regions.

  6. Aircraft to aircraft intercomparison during SEMAPHORE

    Science.gov (United States)

    Lambert, Dominique; Durand, Pierre

    1998-10-01

    During the Structure des Echanges Mer-Atmosphère, Propriétés des Hétérogénéités Océaniques: Recherche Expérimentale (SEMAPHORE) experiment, performed in the Azores region in 1993, two French research aircraft were simultaneously used for in situ measurements in the atmospheric boundary layer. We present the results obtained from one intercomparison flight between the two aircraft. The mean parameters generally agree well, although the temperature has to be slightly shifted in order to be in agreement for the two aircraft. A detailed comparison of the turbulence parameters revealed no bias. The agreement is good for variances and is satisfactory for fluxes and skewness. A thorough study of the errors involved in flux computation revealed that the greatest accuracy is obtained for latent heat flux. Errors in sensible heat flux are considerably greater, and the worst results are obtained for momentum flux. The latter parameter, however, is more accurate than expected from previous parameterizations.

  7. Development of fuel cell systems for aircraft applications based on synthetic fuels

    Energy Technology Data Exchange (ETDEWEB)

    Pasel, J.; Samsun, R.C.; Doell, C.; Peters, R.; Stolten, D. [Forschungszentrum Juelich GmbH (Germany)

    2010-07-01

    At present, in the aviation sector considerable scientific project work deals with the development of fuel cell systems based on synthetic fuels to be integrated in future aircraft. The benefits of fuel cell systems in aircraft are various. They offer the possibility to simplify the aircraft layout. Important systems, i.e. the gas turbine powered auxiliary power unit (APU) for electricity supply, the fuel tank inserting system and the water tank, can be substituted by one single system, the fuel cell system. Additionally, the energy demand for ice protection can be covered assisted by fuel cell systems. These measures reduce the consumption of jet fuel, increase aircraft efficiency and allow the operation at low emissions. Additionally, the costs for aircraft related investments, for aircraft maintenance and operation can be reduced. On the background of regular discussions about environmental concerns (global warming) of kerosene Jet A-1 and its availability, which might be restricted in a few years, the aircraft industry is keen to employ synthetic, sulfur-free fuels such as Fischer-Tropsch fuels. These comprise Bio-To-Liquid and Gas-To-Liquid fuels. Within this field of research the Institute of Energy Research (IEF-3) in Juelich develops complete and compact fuel cell systems based on the autothermal reforming of these kinds of fuels in cooperation with industry. This paper reports about this work. (orig.)

  8. Examining the Relationship Between Passenger Airline Aircraft Maintenance Outsourcing and Aircraft Safety

    Science.gov (United States)

    Monaghan, Kari L.

    The problem addressed was the concern for aircraft safety rates as they relate to the rate of maintenance outsourcing. Data gathered from 14 passenger airlines: AirTran, Alaska, America West, American, Continental, Delta, Frontier, Hawaiian, JetBlue, Midwest, Northwest, Southwest, United, and USAir covered the years 1996 through 2008. A quantitative correlational design, utilizing Pearson's correlation coefficient, and the coefficient of determination were used in the present study to measure the correlation between variables. Elements of passenger airline aircraft maintenance outsourcing and aircraft accidents, incidents, and pilot deviations within domestic passenger airline operations were analyzed, examined, and evaluated. Rates of maintenance outsourcing were analyzed to determine the association with accident, incident, and pilot deviation rates. Maintenance outsourcing rates used in the evaluation were the yearly dollar expenditure of passenger airlines for aircraft maintenance outsourcing as they relate to the total airline aircraft maintenance expenditures. Aircraft accident, incident, and pilot deviation rates used in the evaluation were the yearly number of accidents, incidents, and pilot deviations per miles flown. The Pearson r-values were calculated to measure the linear relationship strength between the variables. There were no statistically significant correlation findings for accidents, r(174)=0.065, p=0.393, and incidents, r(174)=0.020, p=0.793. However, there was a statistically significant correlation for pilot deviation rates, r(174)=0.204, p=0.007 thus indicating a statistically significant correlation between maintenance outsourcing rates and pilot deviation rates. The calculated R square value of 0.042 represents the variance that can be accounted for in aircraft pilot deviation rates by examining the variance in aircraft maintenance outsourcing rates; accordingly, 95.8% of the variance is unexplained. Suggestions for future research include

  9. Propulsion Selection for 85kft Remotely Piloted Atmospheric Science Aircraft

    Science.gov (United States)

    Bents, David J.; Mockler, Ted; Maldonado, Jaime; Hahn, Andrew; Cyrus, John; Schmitz, Paul; Harp, Jim; King, Joseph

    1996-01-01

    This paper describes how a 3 stage turbocharged gasoline engine was selected to power NASA's atmospheric science unmanned aircraft now under development. The airplane, whose purpose is to fly sampling instruments through targeted regions of the upper atmosphere at the exact location and time (season, time of day) where the most interesting chemistry is taking place, must have a round trip range exceeding 1000 km, carry a payload of about 500 lb to altitudes exceeding 80 kft over the site, and be able to remain above that altitude for at least 30 minutes before returning to base. This is a subsonic aircraft (the aerodynamic heating and shock associated with supersonic flight could easily destroy the chemical species that are being sampled) and it must be constructed so it will operate out of small airfields at primitive remote sites worldwide, under varying climate and weather conditions. Finally it must be low cost, since less than $50 M is available for its development. These requirements put severe constraints on the aircraft design (for example, wing loading in the vicinity of 10 psf) and have in turn limited the propulsion choices to already-existing hardware, or limited adaptations of existing hardware. The only candidate that could emerge under these circumstances was a propeller driven aircraft powered by spark ignited (SI) gasoline engines, whose intake pressurization is accomplished by multiple stages of turbo-charging and intercooling. Fortunately the turbocharged SI powerplant, owing to its rich automotive heritage and earlier intensive aero powerplant development during WWII, enjoys in addition to its potentially low development costs some subtle physical advantages (arising from its near-stochiometric combustion) that may make it smaller and lighter than either a turbine engine or a diesel for these altitudes. Just as fortunately, the NASA/industry team developing this aircraft includes the same people who built multi-stage turbocharged SI powerplants

  10. Cosmic radiation dosimetry onboard aircrafts at the brazilian airspace

    International Nuclear Information System (INIS)

    Federico, Claudio Antonio

    2011-01-01

    The objective of this work is the establishment of a dosimetric system for the aircrew in the domestic territory. A technique to perform measurements of ambient dose equivalent in aircrafts was developed. An active detector was evaluated for onboard aircraft use, testing its adequacy to this specific type of measurement as well as its susceptibility to the magnetic and electromagnetic interferences. The equipment was calibrated in standard radiation beams and in a special field of the European Laboratory CERN, that reproduces with great proximity the real spectrum in aircraft flight altitudes; it was also tested in several flights, in an Brazilian Air Force's aircraft. The results were evaluated and compared with those obtained from several computational programs for cosmic radiation estimates, with respect to its adequacy for use in the South American region. The program CARI-6 was selected to evaluate the estimated averaged effective doses for the aircrew who operate in this region. A statistical distribution of aircrew effective doses in South America and Caribe was made, and the results show that a great part of this aircrew members are subjected to annual effective doses that exceed the dose limits for the members of the public. Additionally, a preliminary passive dosemeter, based in thermoluminescent detectors, was proposed; international collaborations with United Kingdom and Italy were established for joint measurements of the ambient equivalent doses in aircrafts. (author)

  11. 150 Passenger Commercial Aircraft

    Science.gov (United States)

    Bucovsky, Adrian; Romli, Fairuz I.; Rupp, Jessica

    2002-01-01

    It has been projected that the need for a short-range mid-sized, aircraft is increasing. The future strategy to decrease long-haul flights will increase the demand for short-haul flights. Since passengers prefer to meet their destinations quickly, airlines will increase the frequency of flights, which will reduce the passenger load on the aircraft. If a point-to-point flight is not possible, passengers will prefer only a one-stop short connecting flight to their final destination. A 150-passenger aircraft is an ideal vehicle for these situations. It is mid-sized aircraft and has a range of 3000 nautical miles. This type of aircraft would market U.S. domestic flights or inter-European flight routes. The objective of the design of the 150-passenger aircraft is to minimize fuel consumption. The configuration of the aircraft must be optimized. This aircraft must meet CO2 and NOx emissions standards with minimal acquisition price and operating costs. This report contains all the work that has been performed for the completion of the design of a 150 passenger commercial aircraft. The methodology used is the Technology Identification, Evaluation, and Selection (TIES) developed at Georgia Tech Aerospace Systems Design laboratory (ASDL). This is an eight-step conceptual design process to evaluate the probability of meeting the design constraints. This methodology also allows for the evaluation of new technologies to be implemented into the design. The TIES process begins with defining the problem with a need established and a market targeted. With the customer requirements set and the target values established, a baseline concept is created. Next, the design space is explored to determine the feasibility and viability of the baseline aircraft configuration. If the design is neither feasible nor viable, new technologies can be implemented to open up the feasible design space and allow for a plausible solution. After the new technologies are identified, they must be evaluated

  12. Measuring Single-Domain Antibody Interactions with Epitopes in Jet Fuel Using Microscale Thermophoresis

    Science.gov (United States)

    2015-01-01

    hearing loss in rats. J. Toxicol. Environ. Health A. 75(5): 299–317. Itah, A. Y., A. A. Brooks, B. O. Ogar, and A. B. Okure. 2009. Biodegradation of...international jet A-1 aviation fuel by microorganisms isolated from aircraft tank and joint hydrant storage systems. Bull. Environ. Contam. Toxicol. 83(3

  13. Vortex wake investigation behind a wing-flap model with jet simulations

    NARCIS (Netherlands)

    Veldhuis, L.L.M.; De Kat, R.

    2008-01-01

    To get a better insight in the effect of jets on vortex development and decay, stereo-PIV measurements were performed in a towing tank behind a flapped aircraft model. The experimental data set yields the wake vortex behavior in a range that extends from the vortex formation stage up to the

  14. Atmospheric electron flux at airplane altitude

    International Nuclear Information System (INIS)

    Enomoto, R.; Chiba, J.; Ogawa, K.; Sumiyoshi, T.; Takasaki, F.; Kifune, T.; Matsubara, Y.; Nishimura, J.

    1991-01-01

    We have developed a new detector to systematically measure the cosmic-ray electron flux at airplane altitudes. We loaded a lead-glass-based electron telescope onto a commercial cargo airplane. The first experiment was carried out using the air route between Narita (Japan) and Sydney (Australia); during this flight we measured the electron flux at various altitudes and latitudes. The thresholds of the electron energies were 1, 2, and 4 GeV. The results agree with a simple estimation using one-dimensional shower theory. A comparison with a Monte Carlo calculation was made

  15. JET Joint Undertaking

    International Nuclear Information System (INIS)

    Keen, B.E.; Kupschus, P.

    1984-09-01

    The report is in sections, as follows. (1) Introduction and summary. (2) A brief description of the origins of the JET Project within the EURATOM fusion programme and the objectives and aims of the device. The basic JET design and the overall philosophy of operation are explained and the first six months of operation of the machine are summarised. The Project Team Structure adopted for the Operation Phase is set out. Finally, in order to set JET's progress in context, other large tokamaks throughout the world and their achievements are briefly described. (3) The activities and progress within the Operation and Development Department are set out; particularly relating to its responsibilities for the operation and maintenance of the tokamak and for developing the necessary engineering equipment to enhance the machine to full performance. (4) The activities and progress within the Scientific Department are described; particularly relating to the specification, procurement and operation of diagnostic equipment; definition and execution of the programme; and the interpretation of experimental results. (5) JET's programme plans for the immediate future and a broad outline of the JET Development Plan to 1990 are given. (author)

  16. The NASA Earth Research-2 (ER-2) Aircraft: A Flying Laboratory for Earth Science Studies

    Science.gov (United States)

    Navarro, Robert

    2007-01-01

    The National Aeronautics and Space Administration Dryden Flight Research Center, Edwards, California, has two Lockheed Martin Corporation (Bethesda, Maryland) Earth Research-2 (ER2) aircraft that serve as high-altitude and long-range flying laboratories. The ER-2 aircraft has been successfully utilized to conduct scientific studies of stratospheric and tropospheric chemistry, land-use mapping, disaster assessment, preliminary testing and calibration and validation of satellite sensors. The research missions for the ER-2 aircraft are planned, implemented, and managed by the Dryden Flight Research Center Science Mission Directorate. Maintenance and instrument payload integration is conducted by Dryden personnel. The ER-2 aircraft provides experimenters with a wide array of payload accommodations areas with suitable environment control with required electrical and mechanical interfaces. Missions may be flown out of Dryden or from remote bases worldwide, according to research requirements. The NASA ER-2 aircraft is utilized by a variety of customers, including U.S. Government agencies, civilian organizations, universities, and state governments. The combination of the ER-2 aircraft s range, endurance, altitude, payload power, payload volume and payload weight capabilities complemented by a trained maintenance and operations team provides an excellent and unique platform system to the science community and other customers.

  17. Identification of Aircraft Hazards

    Energy Technology Data Exchange (ETDEWEB)

    K. Ashley

    2006-12-08

    Aircraft hazards were determined to be potentially applicable to a repository at Yucca Mountain in ''Monitored Geological Repository External Events Hazards Screening Analysis'' (BSC 2005 [DIRS 174235], Section 6.4.1). That determination was conservatively based upon limited knowledge of flight data in the area of concern and upon crash data for aircraft of the type flying near Yucca Mountain. The purpose of this report is to identify specific aircraft hazards that may be applicable to a monitored geologic repository (MGR) at Yucca Mountain, using NUREG-0800, ''Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants'' (NRC 1987 [DIRS 103124], Section 3.5.1.6), as guidance for the inclusion or exclusion of identified aircraft hazards. The intended use of this report is to provide inputs for further screening and analysis of identified aircraft hazards based upon the criteria that apply to Category 1 and Category 2 event sequence analyses as defined in 10 CFR 63.2 [DIRS 176544] (Section 4). The scope of this report includes the evaluation of military, private, and commercial use of airspace in the 100-mile regional setting of the repository at Yucca Mountain with the potential for reducing the regional setting to a more manageable size after consideration of applicable screening criteria (Section 7).

  18. IDENTIFICATION OF AIRCRAFT HAZARDS

    International Nuclear Information System (INIS)

    K.L. Ashley

    2005-01-01

    Aircraft hazards were determined to be potentially applicable to a repository at Yucca Mountain in the ''Monitored Geological Repository External Events Hazards Screening Analysis'' (BSC 2004, Section 6.4.1). That determination was conservatively based on limited knowledge of flight data in the area of concern and on crash data for aircraft of the type flying near Yucca Mountain. The purpose of this report is to identify specific aircraft hazards that may be applicable to a Monitored Geologic Repository (MGR) at Yucca Mountain using NUREG-0800, ''Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants'' (NRC 1987, Section 3.5.1.6), as guidance for the inclusion or exclusion of identified aircraft hazards. NUREG-0800 is being used here as a reference because some of the same considerations apply. The intended use of this report is to provide inputs for further screening and analysis of the identified aircraft hazards based on the criteria that apply to Category 1 and 2 event sequence analyses as defined in 10 CFR 63.2 (see Section 4). The scope of this technical report includes the evaluation of military, private, and commercial use of airspace in the 100-mile regional setting of the MGR at Yucca Mountain with the potential for reducing the regional setting to a more manageable size after consideration of applicable screening criteria (see Section 7)

  19. Identification of Aircraft Hazards

    International Nuclear Information System (INIS)

    K. Ashley

    2006-01-01

    Aircraft hazards were determined to be potentially applicable to a repository at Yucca Mountain in ''Monitored Geological Repository External Events Hazards Screening Analysis'' (BSC 2005 [DIRS 174235], Section 6.4.1). That determination was conservatively based upon limited knowledge of flight data in the area of concern and upon crash data for aircraft of the type flying near Yucca Mountain. The purpose of this report is to identify specific aircraft hazards that may be applicable to a monitored geologic repository (MGR) at Yucca Mountain, using NUREG-0800, ''Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants'' (NRC 1987 [DIRS 103124], Section 3.5.1.6), as guidance for the inclusion or exclusion of identified aircraft hazards. The intended use of this report is to provide inputs for further screening and analysis of identified aircraft hazards based upon the criteria that apply to Category 1 and Category 2 event sequence analyses as defined in 10 CFR 63.2 [DIRS 176544] (Section 4). The scope of this report includes the evaluation of military, private, and commercial use of airspace in the 100-mile regional setting of the repository at Yucca Mountain with the potential for reducing the regional setting to a more manageable size after consideration of applicable screening criteria (Section 7)

  20. JET Joint Undertaking

    International Nuclear Information System (INIS)

    Keen, B.E.

    1986-03-01

    This is an overview summary of the scientific and technical advances at JET during the year 1985, supplemented by appendices of detailed contributions (in preprint form) of eight of the more important JET articles produced during that year. It is aimed not only at specialists and experts but also at a more general scientific community. Thus there is a brief summary of the background to the project, a description of the basic objectives of JET and the principle design features of the machine. The new structure of the Project Team is also explained. Developments and future plans are included. Improvements considered are those which are designed to overcome certain limitations encountered generally on Tokamaks, particularly those concerned with density limits, with plasma MHD behaviour, with impurities and with plasma transport. There is also a complete list of articles, reports and conference papers published in 1985 - there are 167 such items listed. (UK)

  1. Dietary Recommendations for Cyclists during Altitude Training

    Science.gov (United States)

    Michalczyk, Małgorzata; Czuba, Miłosz; Zydek, Grzegorz; Zając, Adam; Langfort, Józef

    2016-01-01

    The concept of altitude or hypoxic training is a common practice in cycling. However, several strategies for training regimens have been proposed, like “live high, train high” (LH-TH), “live high, train low” (LH-TL) or “intermittent hypoxic training” (IHT). Each of them combines the effect of acclimatization and different training protocols that require specific nutrition. An appropriate nutrition strategy and adequate hydration can help athletes achieve their fitness and performance goals in this unfriendly environment. In this review, the physiological stress of altitude exposure and training will be discussed, with specific nutrition recommendations for athletes training under such conditions. However, there is little research about the nutrition demands of athletes who train at moderate altitude. Our review considers energetic demands and body mass or body composition changes due to altitude training, including respiratory and urinary water loss under these conditions. Carbohydrate intake recommendations and hydration status are discussed in detail, while iron storage and metabolism is also considered. Last, but not least the risk of increased oxidative stress under hypoxic conditions and antioxidant supplementation suggestions are presented. PMID:27322318

  2. Dietary Recommendations for Cyclists during Altitude Training.

    Science.gov (United States)

    Michalczyk, Małgorzata; Czuba, Miłosz; Zydek, Grzegorz; Zając, Adam; Langfort, Józef

    2016-06-18

    The concept of altitude or hypoxic training is a common practice in cycling. However, several strategies for training regimens have been proposed, like "live high, train high" (LH-TH), "live high, train low" (LH-TL) or "intermittent hypoxic training" (IHT). Each of them combines the effect of acclimatization and different training protocols that require specific nutrition. An appropriate nutrition strategy and adequate hydration can help athletes achieve their fitness and performance goals in this unfriendly environment. In this review, the physiological stress of altitude exposure and training will be discussed, with specific nutrition recommendations for athletes training under such conditions. However, there is little research about the nutrition demands of athletes who train at moderate altitude. Our review considers energetic demands and body mass or body composition changes due to altitude training, including respiratory and urinary water loss under these conditions. Carbohydrate intake recommendations and hydration status are discussed in detail, while iron storage and metabolism is also considered. Last, but not least the risk of increased oxidative stress under hypoxic conditions and antioxidant supplementation suggestions are presented.

  3. Ocular morbidity among porters at high altitudes.

    Science.gov (United States)

    Gnyawali, Subodh; Shrestha, Gauri Shankar; Khanal, Safal; Dennis, Talisa; Spencer, John C

    2017-01-01

    High altitude, often characterized by settings over 2400m, can be detrimental to the human body and pose a significant risk to ocular health. Reports concerning various ocular morbidities occurring as a consequence of high altitude are limited in the current literature. This study was aimed at evaluating the ocular health of porters working at high altitudesof Himalayas in Nepal. A mobile eye clinic was set up in Ghat and patient data were collected from its out- patient unit by a team of seven optometrists which was run for five days. Ghat is a small village in north-eastern Nepal, located at 2860 m altitude. Travellers walking through the trekking route were invited to get their eyes checked at the clinic. Comprehensive ocular examinations were performed, including visual acuities, objective and subjective refraction, anterior and posterior segment evaluations, and intraocular pressure measurements; blood pressure and blood glucose levels were also measured as required. Ocular therapeutics, prescription glasses, sunglasses and ocular health referrals were provided free of cost as necessary. A total of 1890 people visited the eye clinic, among which 57.4% (n=1084) were porters. Almost half of the porters had an ocular morbidity. Correctable refractive error was most prevalent, with other ocular health-related complications, including dry eye disease, infectious disorders, glaucoma and cataract. Proper provision of regular and effective eye care services should be made more available for those residing at these high altitudes in Nepal. © NEPjOPH.

  4. Altitude, Orthocenter of a Triangle and Triangulation

    Directory of Open Access Journals (Sweden)

    Coghetto Roland

    2016-03-01

    Full Text Available We introduce the altitudes of a triangle (the cevians perpendicular to the opposite sides. Using the generalized Ceva’s Theorem, we prove the existence and uniqueness of the orthocenter of a triangle [7]. Finally, we formalize in Mizar [1] some formulas [2] to calculate distance using triangulation.

  5. 76 FR 11675 - IFR Altitudes; Miscellaneous Amendments

    Science.gov (United States)

    2011-03-03

    ... action is needed because of changes occurring in the National Airspace System. These changes are designed... matters of flight safety and operational efficiency in the National Airspace System, are related to... RIVER, AK NDB BARTER ISLAND, AK NDB... 2000 From To MEA MAA Sec. 95.3000 Low Altitude RNAV Routes Sec...

  6. Dietary Recommendations for Cyclists during Altitude Training

    Directory of Open Access Journals (Sweden)

    Małgorzata Michalczyk

    2016-06-01

    Full Text Available The concept of altitude or hypoxic training is a common practice in cycling. However, several strategies for training regimens have been proposed, like “live high, train high” (LH-TH, “live high, train low” (LH-TL or “intermittent hypoxic training” (IHT. Each of them combines the effect of acclimatization and different training protocols that require specific nutrition. An appropriate nutrition strategy and adequate hydration can help athletes achieve their fitness and performance goals in this unfriendly environment. In this review, the physiological stress of altitude exposure and training will be discussed, with specific nutrition recommendations for athletes training under such conditions. However, there is little research about the nutrition demands of athletes who train at moderate altitude. Our review considers energetic demands and body mass or body composition changes due to altitude training, including respiratory and urinary water loss under these conditions. Carbohydrate intake recommendations and hydration status are discussed in detail, while iron storage and metabolism is also considered. Last, but not least the risk of increased oxidative stress under hypoxic conditions and antioxidant supplementation suggestions are presented.

  7. Structural Health Monitoring of Transport Aircraft with Fuzzy Logic Modeling

    Directory of Open Access Journals (Sweden)

    Ray C. Chang

    2013-01-01

    Full Text Available A structural health monitoring method based on the concept of static aeroelasticity is presented in this paper. This paper focuses on the estimation of these aeroelastic effects on older transport aircraft, in particular the structural components that are most affected, in severe atmospheric turbulence. Because the structural flexibility properties are mostly unknown to aircraft operators, only the trend, not the magnitude, of these effects is estimated. For this purpose, one useful concept in static aeroelastic effects for conventional aircraft structures is that under aeroelastic deformation the aerodynamic center should move aft. This concept is applied in the present paper by using the fuzzy-logic aerodynamic models. A twin-jet transport aircraft in severe atmospheric turbulence involving plunging motion is examined. It is found that the pitching moment derivatives in cruise with moderate to severe turbulence in transonic flight indicate some degree of abnormality in the stabilizer (i.e., the horizontal tail. Therefore, the horizontal tail is the most severely affected structural component of the aircraft probably caused by vibration under the dynamic loads induced by turbulence.

  8. Structural analysis of aircraft impact on a nuclear powered ship

    International Nuclear Information System (INIS)

    Dietrich, R.

    1976-01-01

    As part of a general safety analysis, the reliability against structural damage due to an aircraft crash on a nuclear powered ship is evaluated. This structural analysis is an aid in safety design. It is assumed that a Phantom military jet-fighter hits a nuclear powered ship. The total reaction force due to such an aircraft impact on a rigid barrier is specified in the guidelines of the Reaktor-Sicherheitskommission (German Safety Advisory Committee) for pressurized water reactors. This paper investigates the aircraft impact on the collision barrier at the side of the ship. The aircraft impact on top of the reactor hatchway is investigated by another analysis. It appears that the most unfavorable angle of impact is always normal to the surface of the collision barrier. Consequently, only normal impact will be considered here. For the specific case of an aircraft striking a nuclear powered ship, the following two effects are considered: Local penetration and dynamic response of the structure. (Auth.)

  9. Jet shapes in hadron and electron colliders

    International Nuclear Information System (INIS)

    Wainer, N.

    1993-05-01

    High energy jets are observed both in hadronic machines like the Tevatron and electron machines like LEP. These jets have an extended structure in phase space which can be measured. This distribution is usually called the jet shape. There is an intrinsic relation between jet variables, like energy and direction, the jet algorithm used, and the jet shape. Jet shape differences can be used to separate quark and gluon jets

  10. Galaxies with jet streams

    International Nuclear Information System (INIS)

    Breuer, R.

    1981-01-01

    Describes recent research work on supersonic gas flow. Notable examples have been observed in cosmic radio sources, where jet streams of galactic dimensions sometimes occur, apparently as the result of interaction between neighbouring galaxies. The current theory of jet behaviour has been convincingly demonstrated using computer simulation. The surprisingly long-term stability is related to the supersonic velocity, and is analagous to the way in which an Appollo spacecraft re-entering the atmosphere supersonically is protected by the gas from the burning shield. (G.F.F.)

  11. OPAL Jet Chamber Prototype

    CERN Multimedia

    OPAL was one of the four experiments installed at the LEP particle accelerator from 1989 - 2000. OPAL's central tracking system consists of (in order of increasing radius) a silicon microvertex detector, a vertex detector, a jet chamber, and z-chambers. All the tracking detectors work by observing the ionization of atoms by charged particles passing by: when the atoms are ionized, electrons are knocked out of their atomic orbitals, and are then able to move freely in the detector. These ionization electrons are detected in the dirfferent parts of the tracking system. This piece is a prototype of the jet chambers

  12. Jet pump assisted artery

    Science.gov (United States)

    1975-01-01

    A procedure for priming an arterial heat pump is reported; the procedure also has a means for maintaining the pump in a primed state. This concept utilizes a capillary driven jet pump to create the necessary suction to fill the artery. Basically, the jet pump consists of a venturi or nozzle-diffuser type constriction in the vapor passage. The throat of this venturi is connected to the artery. Thus vapor, gas, liquid, or a combination of the above is pumped continuously out of the artery. As a result, the artery is always filled with liquid and an adequate supply of working fluid is provided to the evaporator of the heat pipe.

  13. Locating industrial VOC sources with aircraft observations

    International Nuclear Information System (INIS)

    Toscano, P.; Gioli, B.; Dugheri, S.; Salvini, A.; Matese, A.; Bonacchi, A.; Zaldei, A.; Cupelli, V.; Miglietta, F.

    2011-01-01

    Observation and characterization of environmental pollution, focussing on Volatile Organic Compounds (VOCs), in a high-risk industrial area, are particularly important in order to provide indications on a safe level of exposure, indicate eventual priorities and advise on policy interventions. The aim of this study is to use the Solid Phase Micro Extraction (SPME) method to measure VOCs, directly coupled with atmospheric measurements taken on a small aircraft environmental platform, to evaluate and locate the presence of VOC emission sources in the Marghera industrial area. Lab analysis of collected SPME fibres and subsequent analysis of mass spectrum and chromatograms in Scan Mode allowed the detection of a wide range of VOCs. The combination of this information during the monitoring campaign allowed a model (Gaussian Plume) to be implemented that estimates the localization of emission sources on the ground. - Highlights: → Flight plan aimed at sampling industrial area at various altitudes and locations. → SPME sampling strategy was based on plume detection by means of CO 2 . → Concentrations obtained were lower than the limit values or below the detection limit. → Scan mode highlighted presence of γ-butyrolactone (GBL) compound. → Gaussian dispersion modelling was used to estimate GBL source location and strength. - An integrated strategy based on atmospheric aircraft observations and dispersion modelling was developed, aimed at estimating spatial location and strength of VOC point source emissions in industrial areas.

  14. Measurements of neutron radiation in aircraft

    International Nuclear Information System (INIS)

    Vukovic, B.; Poje, M.; Varga, M.; Radolic, V.; Miklavcic, I.; Faj, D.; Stanic, D.; Planinic, J.

    2010-01-01

    Radiation environment is a complex mixture of charged particles of the solar and galactic origin, as well as of secondary particles created in an interaction of galactic cosmic particles with the nuclei of the Earth's atmosphere. A radiation field at aircraft altitude consists of different types of particles, mainly photons, electrons, positrons and neutrons, with a large energy range. In order to measure a neutron component of the cosmic radiation, we investigated a few combinations of a track etch detector (CR-39, LR-115) with a plastic converter or boron foil. Detector calibration was performed on neutrons coming from the nuclear reactor, as well as in the CERN-EU high-energy Reference Field (CERF) facility. From November 2007 to September 2008, the neutron dose equivalent was measured by the track detectors during five aircraft flights, in the north geographical latitude from 21 o to 58 o ; the respective average dose rate, determined by using the D-4 detector (CR-39/B), was H n =5.9 μSv/h. The photon dose rate, measured by the electronic dosimeter RAD-60 SE, had the average value of H f =1.4 μSv/h.

  15. Measurements of neutron radiation in aircraft

    Energy Technology Data Exchange (ETDEWEB)

    Vukovic, B.; Poje, M.; Varga, M.; Radolic, V.; Miklavcic, I. [Department of Physics, University of Osijek, Osijek, P.O. Box 125 (Croatia); Faj, D. [Clinical Hospital Osijek (Croatia); Stanic, D. [Department of Physics, University of Osijek, Osijek, P.O. Box 125 (Croatia); Planinic, J., E-mail: planinic@ffos.h [Department of Physics, University of Osijek, Osijek, P.O. Box 125 (Croatia)

    2010-12-15

    Radiation environment is a complex mixture of charged particles of the solar and galactic origin, as well as of secondary particles created in an interaction of galactic cosmic particles with the nuclei of the Earth's atmosphere. A radiation field at aircraft altitude consists of different types of particles, mainly photons, electrons, positrons and neutrons, with a large energy range. In order to measure a neutron component of the cosmic radiation, we investigated a few combinations of a track etch detector (CR-39, LR-115) with a plastic converter or boron foil. Detector calibration was performed on neutrons coming from the nuclear reactor, as well as in the CERN-EU high-energy Reference Field (CERF) facility. From November 2007 to September 2008, the neutron dose equivalent was measured by the track detectors during five aircraft flights, in the north geographical latitude from 21{sup o} to 58{sup o}; the respective average dose rate, determined by using the D-4 detector (CR-39/B), was H{sub n}=5.9 {mu}Sv/h. The photon dose rate, measured by the electronic dosimeter RAD-60 SE, had the average value of H{sub f}=1.4 {mu}Sv/h.

  16. X-36 Tailless Fighter Agility Research Aircraft in flight

    Science.gov (United States)

    1997-01-01

    The lack of a vertical tail on the X-36 technology demonstrator is evident as the remotely piloted aircraft flies a low-altitude research flight above Rogers Dry Lake at Edwards Air Force Base in the California desert on October 30, 1997. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three

  17. Aircraft gas turbines

    Energy Technology Data Exchange (ETDEWEB)

    Arai, M [Kawasaki Heavy Industries Ltd., Kobe (Japan)

    1995-03-01

    Recently the international relationship has been playing an important role in the research, development and production of the aircraft gas turbine. The YSX, which is supposed to be the 100-seat class commercial aircraft, has been planned by Japan Aircraft Development (JADC) as an international cooperative project. Recently many western aeroengine companies have offered the collaboration of small turbofan engines which would be installed on YSX to Japanese aeroengine companies (IHI, KHI and MHI). The YSX is powered by 16,000-20,000 1bs thrust class engines. As for medium turbofan engine (V2500), the V 2500 family of 22,000 to 30,000 1bs thrust has been developed since 1983 through international collaboration by seven aeroengine companies in five nations. In this paper, the recent Japan`s activities of the research, development and production with viewing the world-wide movement, are described. 6 figs.

  18. Hazards from aircraft

    International Nuclear Information System (INIS)

    Grund, J.E.; Hornyik, K.

    1975-01-01

    The siting of nuclear power plants has created innumerable environmental concerns. Among the effects of the ''man-made environment'' one of increasing importance in recent nuclear plant siting hazards analysis has been the concern about aircraft hazards to the nuclear plant. These hazards are of concern because of the possibility that an aircraft may have a malfunction and crash either near the plant or directly into it. Such a crash could be postulated to result, because of missile and/or fire effects, in radioactive releases which would endanger the public health and safety. The majority of studies related to hazards from air traffic have been concerned with the determination of the probability associated with an aircraft striking vulnerable portions of a given plant. Other studies have focused on the structural response to such a strike. This work focuses on the problem of strike probability. 13 references

  19. Observations of Seven Blue/Gigantic Jets above One Storm over the Atlantic Ocean

    Science.gov (United States)

    Liu, N.; Spiva, N.; Dwyer, J. R.; Rassoul, H.; Free, D. L.; Cummer, S. A.

    2013-12-01

    Blue/gigantic jets are electrical discharges developing from thundercloud tops and propagating to the upper atmosphere [e.g., Pasko et al., Nature, 416, 152, 2002; Su et al., Nature, 423, 973, 2003]. Not just producing an impressive display, gigantic jets establish a direct path of electrical contact between the upper troposphere and the lower ionosphere, capable of transferring a large amount of charge between them [Cummer et al., Nat. Geosci., 2, 617, 2009]. It has been suggested that they may play an important role in the earth's electrical environment [e. g., Pasko, Nature, 423, 927, 2003]. Upward discharges from thunderstorms like blue/gigantic jets are believed to originate from lightning leaders escaping from thunderclouds when the cloud's charges of different polarities are not balanced [Krehbiel et al., Nat. Geosci., 1, 233, 2008; Riousset et al., JGR, 115, A00E10, 2010]. On the evening of August 2, 2013, 4 gigantic jets, 2 blue jets and 1 blue starter were recorded within 26 min above a storm over the Atlantic Ocean by a low light level camera from the campus of Florida Institute of Technology. The events were also captured by two all-sky cameras: one again from the Florida Tech campus and the other from a nearby location. According to the NLDN data, positive intra-cloud flashes preceded all events except one gigantic jet. The distance between the observation site to the locations of the NLDN lightning discharges varies from 77 to 82 km. Optical signatures of intra-cloud discharge activities accompanied the events are clearly visible in the videos. The duration of each jet varies from about 300 ms to 1.2 s, and the 1.2 s duration is probably the longest that has been reported to date for jets. Rebrightening of gigantic jet structures occurs for at least two of the events. The upper terminal altitude of the 4 gigantic jets is greater than 76-81 km, the 2 blue jets reach about 48 and 51 km altitude, respectively, and the blue starter reaches 24 km altitude

  20. High altitude pulmonary edema among "Amarnath Yatris"

    Directory of Open Access Journals (Sweden)

    Parvaiz A Koul

    2013-01-01

    Full Text Available Background: Annual pilgrimage (Yatra to the cave shrine of Shri Amarnath Ji′ is a holy ritual among the Hindu devotees of Lord Shiva. Located in the Himalayan Mountain Range (altitude 13,000 ft in south Kashmir, the shrine is visited by thousands of devotees and altitude sickness is reportedly common. Materials and Methods: More than 600,000 pilgrims visited the cave shrine in 2011 and 2012 with 239 recorded deaths. Thirty one patients with suspected altitude sickness were referred from medical centers en-route the cave to Sher-i-Kashmir Institute of Medical Sciences, a tertiary-care center in capital Srinagar (5,000 ft. The clinical features and the response to treatment were recorded. Results: Thirty-one patients (all lowlanders, 19 male; age 18-60 years, median 41 had presented with acute onset breathlessness of 1-4 days (median 1.9 d starting within 12-24 h of a rapid ascent; accompanied by cough (68%, headache (8%, dizziness and nausea (65%. Sixteen patients had associated encephalopathy. Clinical features on admission included tachypnea ( n = 31, tachycardia ( n = 23, bilateral chest rales ( n = 29, cyanosis ( n = 22 and grade 2-4 encephalopathy. Hypoxemia was demonstrable in 24 cases and bilateral infiltrates on radiologic imaging in 29. Ten patients had evidence of high-altitude cerebral edema. All patients were managed with oxygen, steroids, nifedipine, sildenafil and other supportive measures including invasive ventilation ( n = 3. Three patients died due to multiorgan dysfunction. Conclusions: Altitude sickness is common among Amaranath Yatris from the plains and appropriate educational strategies should be invoked for prevention and prompt treatment.

  1. Pathology of high altitude pulmonary oedema

    International Nuclear Information System (INIS)

    Saleem, N.

    2014-01-01

    Objective: To describe autopsy findings in fatal cases of high altitude pulmonary oedema. Study Design: Descriptive study. Place and Duration of Study: The study was carried out between 1999 and 2002 at an army field medical unit in Baltistan, Armed Forces Institute of Pathology, Rawalpindi and Army Medical College, Rawalpindi, Pakistan. Patients and Methods:Autopsies were performed in 17 fatal cases of High Altitude Pulmonary Edema (HAPE) occurring among soldiers serving in Siachen. Results:All cases were males with a mean age of 26.8 years (19-35). The mean altitude at which HAPE occurred was 5192 meters (2895-6492), and the mean duration of stay at these altitudes was 15.3 days (1-30). Eleven individuals had undergone proper acclimatization. The commonest clinical findings were cough (70%), dyspnoea (53%), nausea (47%), headache (41%), vomiting (35%), chest pain (35%) and tightness in chest (24%). Cyanosis and frothy secretions in the nostrils and mouth were present in all but one case. Mean combined weight of lungs was 1470 grams (1070-1810). There was marked congestion of outer and cut surfaces. Interstitial oedema was present in all cases. RBCs and leukocyte infiltrates were seen in 13 and alveolar hyaline membranes in 9 cases. Thrombi were seen in 2 cases. Cerebral oedema was present in 9 cases. Conclusion:HAPE can occur after more than two weeks of stay at high altitudes despite proper acclimatization. Concomitant cerebral oedema is frequently present. Our autopsy findings are consistent with what has been reported previously. (author)

  2. Discharge processes, electric field, and electron energy in ISUAL-recorded gigantic jets

    Science.gov (United States)

    Kuo, Cheng-Ling; Chou, J. K.; Tsai, L. Y.; Chen, A. B.; Su, H. T.; Hsu, R. R.; Cummer, S. A.; Frey, H. U.; Mende, S. B.; Takahashi, Y.; Lee, L. C.

    2009-04-01

    This article reports the first high time resolution measurements of gigantic jets from the Imager of Sprites and Upper Atmospheric Lightning (ISUAL) experiment. The velocity of the upward propagating fully developed jet stage of the gigantic jets was ˜107 m s-1, which is similar to that observed for downward sprite streamers. Analysis of spectral ratios for the fully developed jet emissions gives a reduced E field of 400-655 Td and average electron energy of 8.5-12.3 eV. These values are higher than those in the sprites but are similar to those predicted by streamer models, which implies the existence of streamer tips in fully developed jets. The gigantic jets studied here all contained two distinct photometric peaks. The first peak is from the fully developed jet, which steadily propagates from the cloud top (˜20 km) to the lower ionosphere at ˜90 km. We suggest that the second photometric peak, which occurs ˜1 ms after the first peak, is from a current wave or potential wave-enhanced emissions that originate at an altitude of ˜50 km and extend toward the cloud top. We propose that the fully developed jet serves as an extension of the local ionosphere and produces a lowered ionosphere boundary. As the attachment processes remove the charges, the boundary of the local ionosphere moves up. The current in the channel persists and its contact point with the ionosphere moves upward, which produces the upward surging trailing jets. Imager and photometer data indicate that the lightning activity associated with the gigantic jets likely is in-cloud, and thus the initiation of the gigantic jets is not directly associated with cloud-to-ground discharges.

  3. AIRCRAFT MAINTENANCE HANGAR

    Directory of Open Access Journals (Sweden)

    GEAMBASU Gabriel George

    2017-05-01

    Full Text Available The paper presents the maintenance process that is done on an airplane, at a certain period of time, or after a number of flight hours or cycles and describes the checks performed behind each inspection. The first part of research describes the aircraft maintenance process that has to be done after an updated maintenance manual according with aircraft type, followed by a short introduction about maintenance hangar. The second part of the paper presents a hangar design with a foldable roof and walls, which can be folded or extended, over an airplane when a maintenance process is done, or depending on weather condition.

  4. Turbulent jet in confined counterflow

    Indian Academy of Sciences (India)

    The mean flowfield of a turbulent jet issuing into a confined, uniform counterflow was investigated computationally. Based on dimensional analysis, the jet penetration length was shown to scale with jet-to-counterflow momentum flux ratio. This scaling and the computational results reproduce the well-known correct limit of ...

  5. Elucidating Jet Energy Loss Using Jets Prospects from ATLAS

    CERN Document Server

    Grau, N

    2009-01-01

    Jets at the LHC are expected to provide the testing ground for studying QCD energy loss. In this contribution, we briefly outline the strategy that will be used to measure jets in ATLAS and how we will go about studying energy loss. We describe the utility of measuring the jet $R_{AA}$, the fragmentation function, and heavy flavor jets. Utilizing the collision energy provided by the LHC and the nearly hermetic and highly segmented calorimeter, ATLAS is expected to make important contributions to the understanding of parton energy loss using fully reconstructed jets.

  6. Elucidating Jet Energy Loss Using Jets: Prospects from ATLAS

    International Nuclear Information System (INIS)

    Grau, N.

    2009-01-01

    Jets at the LHC are expected to provide the testing ground for studying QCD energy loss. In this contribution, we briefly outline the strategy that will be used to measure jets in ATLAS and how we will go about studying energy loss. We describe the utility of measuring the jet R AA , the fragmentation function, and heavy flavor jets. Utilizing the collision energy provided by the LHC and the nearly hermetic and highly segmented calorimeter, ATLAS is expected to make important contributions to the understanding of parton energy loss using fully reconstructed jets.

  7. Composite materials for aircraft structures

    National Research Council Canada - National Science Library

    Baker, A. A; Dutton, Stuart; Kelly, Donald

    2004-01-01

    ... materials for aircraft structures / Alan Baker, Stuart Dutton, and Donald Kelly- 2nd ed. p. cm. - (Education series) Rev. ed. of: Composite materials for aircraft structures / edited by B. C. Hos...

  8. STS-46 Atlantis', OV-104's, vertical tail and OMS pods lit up by RCS jet firing

    Science.gov (United States)

    1992-01-01

    STS-46 Atlantis', Orbiter Vehicle (OV) 104's, vertical tail and orbital maneuvering system (OMS) pods are highlighted by the glow of the reaction control system (RCS) jet firings. OV-104 was at an altitude of 128 nautical miles. The remote manipulator system (RMS) arm is partially visible stowed along the port side sill longeron.

  9. Unmanned Aerial Systems Traffic Management (UTM): Safely Enabling UAS Operations in Low-Altitude Airspace

    Science.gov (United States)

    Rios, Joseph

    2016-01-01

    Currently, there is no established infrastructure to enable and safely manage the widespread use of low-altitude airspace and UAS flight operations. Given this, and understanding that the FAA faces a mandate to modernize the present air traffic management system through computer automation and significantly reduce the number of air traffic controllers by FY 2020, the FAA maintains that a comprehensive, yet fully automated UAS traffic management (UTM) system for low-altitude airspace is needed. The concept of UTM is to begin by leveraging concepts from the system of roads, lanes, stop signs, rules and lights that govern vehicles on the ground today. Building on its legacy of work in air traffic management (ATM), NASA is working with industry to develop prototype technologies for a UAS Traffic Management (UTM) system that would evolve airspace integration procedures for enabling safe, efficient low-altitude flight operations that autonomously manage UAS operating in an approved low-altitude airspace environment. UTM is a cloud-based system that will autonomously manage all traffic at low altitudes to include UASs being operated beyond visual line of sight of an operator. UTM would thus enable safe and efficient flight operations by providing fully integrated traffic management services such as airspace design, corridors, dynamic geofencing, severe weather and wind avoidance, congestion management, terrain avoidance, route planning re-routing, separation management, sequencing spacing, and contingency management. UTM removes the need for human operators to continuously monitor aircraft operating in approved areas. NASA envisions concepts for two types of UTM systems. The first would be a small portable system, which could be moved between geographical areas in support of operations such as precision agriculture and public safety. The second would be a Persistent system, which would support low-altitude operations in an approved area by providing continuous automated

  10. JET joint undertaking

    International Nuclear Information System (INIS)

    1984-06-01

    JET began operations on 25 June 1983. This annual report contains administrative information and a general review of scientific and technical developments. Among them are vacuum systems, toroidal and poloidal field systems, power supplies, neutral beam heating, radiofrequency heating, remote handling, tritium handling, control and data acquisition systems and diagnostic systems

  11. Triton burnup in JET

    International Nuclear Information System (INIS)

    Chipsham, E.; Jarvis, O.N.; Sadler, G.

    1989-01-01

    Triton burnup measurements have been made at JET using time-integrated copper activation and time-resolved silicon detector techniques. The results confirm the classical nature of both the confinement and the slowing down of the 1 MeV tritons in a plasma. (author) 8 refs., 3 figs

  12. Vortex diode jet

    Science.gov (United States)

    Houck, Edward D.

    1994-01-01

    A fluid transfer system that combines a vortex diode with a jet ejector to transfer liquid from one tank to a second tank by a gas pressurization method having no moving mechanical parts in the fluid system. The vortex diode is a device that has a high resistance to flow in one direction and a low resistance to flow in the other.

  13. Jets in Active Galaxies

    Indian Academy of Sciences (India)

    which are rapidly rotating neutron stars emitting narrow beams of radiation. Images of ... rized into starburst galaxies and AGN powered by SMBHs. The ..... swer lies in the relativistic motion of the jets which boosts the flux density of .... radio cores, detection of ... to as synchrotron self-Compton or SSC, or those of the cosmic.

  14. LHCb jet reconstruction

    International Nuclear Information System (INIS)

    Francisco, Oscar; Rangel, Murilo; Barter, William; Bursche, Albert; Potterat, Cedric; Coco, Victor

    2012-01-01

    Full text: The Large Hadron Collider (LHC) is the most powerful particle accelerator in the world. It has been designed to collide proton beams at an energy up to 14 TeV in the center of mass. In 2011, the data taking was done with a center of mass energy of 7 TeV, the instant luminosity has reached values greater than 4 X 10 32 cm -2 s -1 and the integrated luminosity reached the value of 1,02fb -1 on the LHCb. The jet reconstruction is fundamental to observe events that can be used to test perturbative QCD (pQCD). It also provides a way to observe standard model channels and searches for new physics like SUSY. The anti-kt algorithm is a jet reconstruction algorithm that is based on the distance of the particles on the space ηX φ and on the transverse momentum of particles. To maximize the energy resolution all information about the trackers and the colorimeters are used on the LHCb experiment to create objects called particle flow objects that are used as input to anti-kt algorithm. The LHCb is specially interesting for jets studies because its η region is complementary to the others main experiments on LHC. We will present the first results of jet reconstruction using 2011 LHCb data. (author)

  15. LHCb jet reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Francisco, Oscar; Rangel, Murilo [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil); Barter, William [University of Cambridge, Cambridge (United Kingdom); Bursche, Albert [Universitat Zurich, Zurich (Switzerland); Potterat, Cedric [Universitat de Barcelona, Barcelona (Spain); Coco, Victor [Nikhef National Institute for Subatomic Physics, Amsterdam (Netherlands)

    2012-07-01

    Full text: The Large Hadron Collider (LHC) is the most powerful particle accelerator in the world. It has been designed to collide proton beams at an energy up to 14 TeV in the center of mass. In 2011, the data taking was done with a center of mass energy of 7 TeV, the instant luminosity has reached values greater than 4 X 10{sup 32} cm{sup -2}s{sup -1} and the integrated luminosity reached the value of 1,02fb{sup -1} on the LHCb. The jet reconstruction is fundamental to observe events that can be used to test perturbative QCD (pQCD). It also provides a way to observe standard model channels and searches for new physics like SUSY. The anti-kt algorithm is a jet reconstruction algorithm that is based on the distance of the particles on the space {eta}X {phi} and on the transverse momentum of particles. To maximize the energy resolution all information about the trackers and the colorimeters are used on the LHCb experiment to create objects called particle flow objects that are used as input to anti-kt algorithm. The LHCb is specially interesting for jets studies because its {eta} region is complementary to the others main experiments on LHC. We will present the first results of jet reconstruction using 2011 LHCb data. (author)

  16. Fastener investigation in JET

    Energy Technology Data Exchange (ETDEWEB)

    Bunting, P., E-mail: patrick.bunting@ccfe.ac.uk; Thompson, V.; Riccardo, V.

    2016-11-15

    Highlights: • Experimental work to identify the cause of a bolt seizure inside the JET vessel. • Taguchi method used to reduce tests to 16 while covering 5 parameters. • Experimental work was unable to reproduce bolt seizure. • Thread contamination had little effect on the bolt performance. - Abstract: JET is an experimental fusion reactor consisting of magnetically confined, high temperature plasma inside a large ultra-high vacuum chamber. The inside of the chamber is protected from the hot plasma with tiles made from beryllium, tungsten, carbon composites and other materials bolted to the vessel wall. The study was carried out in response to a JET fastener seizing inside the vacuum vessel. The following study looks at characterising the magnitude of the individual factors affecting the fastener break away torque. This was carried out using a statistical approach, the Taguchi method: isolating the net effect of individual factors present in a series of tests [1](Grove and Davis, 1992). Given the severe environment within the JET vessel due to the combination of heat, ultra-high vacuum and the high contact pressure in bolt threads, the contributions of localised diffusion bonding is assessed in conjunction with various combinations of bolt and insert material.

  17. Jet Inlet Efficiency

    Science.gov (United States)

    2013-08-08

    AFRL-RW-EG-TR-2014-044 Jet Inlet Efficiency Nigel Plumb Taylor Sykes-Green Keith Williams John Wohleber Munitions Aerodynamics Sciences...CONTRACT NUMBER N/A 5b. GRANT NUMBER N/A 5c. PROGRAM ELEMENT NUMBER N/A 6. AUTHOR(S) Nigel Plumb Taylor Sykes-Green Keith Williams John

  18. Abrasive water jet cutting

    International Nuclear Information System (INIS)

    Leist, K.J.; Funnell, G.J.

    1988-01-01

    In the process of selecting a failed equipment cut-up tool for the process facility modifications (PFM) project, a system using an abrasive water jet (AWJ) was developed and tested for remote disassembly of failed equipment. It is presented in this paper

  19. Development of oxygen scavenger additives for jet fuels

    Energy Technology Data Exchange (ETDEWEB)

    Beaver, B.D.; Demunshi, R.; Sharief, V.; Tian, D.; Teng, Y. [Duquesne Univ., Pittsburgh, PA (United States)

    1995-05-01

    Our current research program is in response to the US Air Force`s FY93 New Initiative entitled {open_quotes}Advanced Fuel Composition and Use.{close_quotes} The critical goal of this initiative is to develop aircraft fuels which can operate at supercritical conditions. This is a vital objective since future aircraft designs will transfer much higher heat loads into the fuel as compared with current heat loads. In this paper it is argued that the thermal stability of most jet fuels would be dramatically improved by the efficient in flight-removal of a fuel`s dissolved oxygen. It is proposed herein to stabilize the bulk fuel by the addition of an additive which will be judiciously designed and programmed to react with oxygen and produce an innocuous product. It is envisioned that a thermally activated reaction will occur, between the oxygen scavenging additive and dissolved oxygen, in a controlled and directed manner. Consequently formation of insoluble thermal degradation products will be limited. It is believed that successful completion of this project will result in the development of a new type of jet fuel additive which will enable current conventional jet fuels to obtain sufficient thermal stability to function in significantly higher temperature regimes. In addition, it is postulated that the successful development of thermally activated oxygen scavengers will also provide the sub-critical thermal stability necessary for future development of endothermic fuels.

  20. Jet-images: computer vision inspired techniques for jet tagging

    Energy Technology Data Exchange (ETDEWEB)

    Cogan, Josh; Kagan, Michael; Strauss, Emanuel; Schwarztman, Ariel [SLAC National Accelerator Laboratory,Menlo Park, CA 94028 (United States)

    2015-02-18

    We introduce a novel approach to jet tagging and classification through the use of techniques inspired by computer vision. Drawing parallels to the problem of facial recognition in images, we define a jet-image using calorimeter towers as the elements of the image and establish jet-image preprocessing methods. For the jet-image processing step, we develop a discriminant for classifying the jet-images derived using Fisher discriminant analysis. The effectiveness of the technique is shown within the context of identifying boosted hadronic W boson decays with respect to a background of quark- and gluon-initiated jets. Using Monte Carlo simulation, we demonstrate that the performance of this technique introduces additional discriminating power over other substructure approaches, and gives significant insight into the internal structure of jets.

  1. Jet-images: computer vision inspired techniques for jet tagging

    International Nuclear Information System (INIS)

    Cogan, Josh; Kagan, Michael; Strauss, Emanuel; Schwarztman, Ariel

    2015-01-01

    We introduce a novel approach to jet tagging and classification through the use of techniques inspired by computer vision. Drawing parallels to the problem of facial recognition in images, we define a jet-image using calorimeter towers as the elements of the image and establish jet-image preprocessing methods. For the jet-image processing step, we develop a discriminant for classifying the jet-images derived using Fisher discriminant analysis. The effectiveness of the technique is shown within the context of identifying boosted hadronic W boson decays with respect to a background of quark- and gluon-initiated jets. Using Monte Carlo simulation, we demonstrate that the performance of this technique introduces additional discriminating power over other substructure approaches, and gives significant insight into the internal structure of jets.

  2. Long Range Aircraft Trajectory Prediction

    OpenAIRE

    Magister, Tone

    2009-01-01

    The subject of the paper is the improvement of the aircraft future trajectory prediction accuracy for long-range airborne separation assurance. The strategic planning of safe aircraft flights and effective conflict avoidance tactics demand timely and accurate conflict detection based upon future four–dimensional airborne traffic situation prediction which is as accurate as each aircraft flight trajectory prediction. The improved kinematics model of aircraft relative flight considering flight ...

  3. Retrieving Storm Electric Fields from Aircraft Field Mill Data. Part 1; Theory

    Science.gov (United States)

    Koshak, W. J.

    2006-01-01

    It is shown that the problem of retrieving storm electric fields from an aircraft instrumented with several electric field mill sensors can be expressed in terms of a standard Lagrange multiplier optimization problem. The method naturally removes aircraft charge from the retrieval process without having to use a high voltage stinger and linearly combined mill data values. It allows a variety of user-supplied physical constraints (the so-called side constraints in the theory of Lagrange multipliers) and also helps improve absolute calibration. Additionally, this paper introduces an alternate way of performing the absolute calibration of an aircraft that has some benefits over conventional analyses. It is accomplished by using the time derivatives of mill and pitch data for a pitch down maneuver performed at high (greater than 1 km) altitude. In Part II of this study, the above methods are tested and then applied to complete a full calibration of a Citation aircraft.

  4. Retrieving Storm Electric Fields From Aircraft Field Mill Data. Part I: Theory

    Science.gov (United States)

    Koshak, W. J.

    2005-01-01

    It is shown that the problem of retrieving storm electric fields from an aircraft instrumented with several electric field mill sensors can be expressed in terms of a standard Lagrange multiplier optimization problem. The method naturally removes aircraft charge from the retrieval process without having to use a high voltage stinger and linearly combined mill data values. It also allows a variety of user-supplied physical constraints (the so-called side constraints in the theory of Lagrange multipliers). Additionally, this paper introduces a novel way of performing the absolute calibration of an aircraft that has several benefits over conventional analyses. In the new approach, absolute calibration is completed by inspecting the time derivatives of mill and pitch data for a pitch down maneuver performed at high (greater than 1 km) altitude. In Part II of this study, the above methods are tested and then applied to complete a full calibration of a Citation aircraft.

  5. Advanced Oxygen Systems for Aircraft (Systemes d’Oxygene Avances)

    Science.gov (United States)

    1996-04-01

    Oxygen Generating System (NAOGS), SAM-TR-80-12, Brooks AFB TX 78235, 1980. 11. Horch TC, Miller RL, Bomar JB, Tedor JB, Holden RD, Ikels KG, and...sieve oxygen generation sys- tem. Data from Horch et al (15). cabin altitude. The minimum and maximum oxygen concen- tration lines depict the...an AV-8A Aircraft; Naval Air Test Center Report No. SY-136R-81, 1981. 15. Horch TC, Miller RL, Bomar JB Jr, Tedor JB, Holden RD, Ikels KG, and

  6. SparkJet characterizations in quiescent and supersonic flowfields

    Science.gov (United States)

    Emerick, T.; Ali, M. Y.; Foster, C.; Alvi, F. S.; Popkin, S.

    2014-12-01

    The aerodynamic community has studied active flow control actuators for some time, and developments have led to a wide variety of devices with various features and operating mechanisms. The design requirements for a practical actuator used for active flow control include reliable operation, requisite frequency and amplitude modulation capabilities, and a reasonable lifespan while maintaining minimal cost and design complexity. An active flow control device called the SparkJet actuator has been developed for high-speed flight control and incorporates no mechanical/moving parts, zero net mass flux capabilities and the ability to tune the operating frequency and momentum throughput. This actuator utilizes electrical power to deliver high-momentum flow with a very fast response time. The SparkJet actuator was characterized on the benchtop using a laser-based microschlieren visualization technique and maximum blast wave and jet front velocities of ~400 and ~310 m/s were, respectively, measured in the flowfield. An increase in jet front velocity from 240 to 310 m/s during subatmospheric (60 kPa) testing reveals that the actuator may have greater control authority at lower ambient pressures, which correspond to high-altitude flight conditions for air vehicles. A SparkJet array was integrated into a flat plate and tested in a Mach 1.5 crossflow. Phase-conditioned shadowgraph results revealed a maximum flow deflection angle of 5° created by the SparkJet 275 µs after the actuator was triggered in single-shot mode. Burst mode operation of frequencies up to 700 Hz revealed similar results during wind tunnel testing. Following these tests, the actuator trigger mechanism was improved and the ability of the actuator to be discharged in burst mode at a frequency of 1 kHz was achieved.

  7. Mean streamwise velocity measurements in a triple jet of equilateral triangular configuration

    Energy Technology Data Exchange (ETDEWEB)

    Moustafa, G.H. (Menoufia Univ. (Egypt). Coll. of Engineering); Sundararajan, T. (IIT Kanpur (India). Dept. of Mechanical Engineering); Rathakrishnan, E. (IIT Kanpur (India). Dept. of Aerospace Engineering)

    1993-09-01

    Multijet flows arise in several applications such as jet engine/rocket combustors, the thrust augmenting ejectors for VTOL/STOL aircraft, and industrial gas burners. In order to achieve proper combustion, thrust development, and reduction in the noise level, it is often desirable to control the inter-mixing between the jets and also the entrainment of the surrounding atmosphere. This, in turn, requires a detailed study of the behavior of high speed jets in multijet configuration. The situation of interest here is an array of three axisymmetric nozzles set in a common end wall with equal spacing in a triangular configuration. The reason why this particular configuration has been chosen is that it promotes bending of the jet axes toward each other, thus leading to greater mixing. In the present study, experiments have been conducted to investigate the effect of stagnation pressure ratio and nozzle spacing upon the mean flow characteristic of compressible jets in triangular configuration. The individual flow features of the vertex jet and the base twin jet are analyzed and their contributions to the axis switching as well as the overall triple jet behavior are highlighted.

  8. The Low-Noise Potential of Distributed Propulsion on a Catamaran Aircraft

    Science.gov (United States)

    Posey, Joe W.; Tinetti, A. F.; Dunn, M. H.

    2006-01-01

    The noise shielding potential of an inboard-wing catamaran aircraft when coupled with distributed propulsion is examined. Here, only low-frequency jet noise from mid-wing-mounted engines is considered. Because low frequencies are the most difficult to shield, these calculations put a lower bound on the potential shielding benefit. In this proof-of-concept study, simple physical models are used to describe the 3-D scattering of jet noise by conceptualized catamaran aircraft. The Fast Scattering Code is used to predict noise levels on and about the aircraft. Shielding results are presented for several catamaran type geometries and simple noise source configurations representative of distributed propulsion radiation. Computational analyses are presented that demonstrate the shielding benefits of distributed propulsion and of increasing the width of the inboard wing. Also, sample calculations using the FSC are presented that demonstrate additional noise reduction on the aircraft fuselage by the use of acoustic liners on the inboard wing trailing edge. A full conceptual aircraft design would have to be analyzed over a complete mission to more accurately quantify community noise levels and aircraft performance, but the present shielding calculations show that a large acoustic benefit could be achieved by combining distributed propulsion and liner technology with a twin-fuselage planform.

  9. Jet substructure using semi-inclusive jet functions in SCET

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Zhong-Bo [Theoretical Division, Los Alamos National Laboratory,Los Alamos, NM 87545 (United States); Department of Physics and Astronomy, University of California,Los Angeles, CA 90095 (United States); Ringer, Felix; Vitev, Ivan [Theoretical Division, Los Alamos National Laboratory,Los Alamos, NM 87545 (United States)

    2016-11-25

    We propose a new method to evaluate jet substructure observables in inclusive jet measurements, based upon semi-inclusive jet functions in the framework of Soft Collinear Effective Theory (SCET). As a first example, we consider the jet fragmentation function, where a hadron h is identified inside a fully reconstructed jet. We introduce a new semi-inclusive fragmenting jet function G{sub i}{sup h}(z=ω{sub J}/ω,z{sub h}=ω{sub h}/ω{sub J},ω{sub J},R,μ), which depends on the jet radius R and the large light-cone momenta of the parton ‘i’ initiating the jet (ω), the jet (ω{sub J}), and the hadron h (ω{sub h}). The jet fragmentation function can then be expressed as a semi-inclusive observable, in the spirit of actual experimental measurements, rather than as an exclusive one. We demonstrate the consistency of the effective field theory treatment and standard perturbative QCD calculations of this observable at next-to-leading order (NLO). The renormalization group (RG) equation for the semi-inclusive fragmenting jet function G{sub i}{sup h}(z,z{sub h},ω{sub J},R,μ) are also derived and shown to follow exactly the usual timelike DGLAP evolution equations for fragmentation functions. The newly obtained RG equations can be used to perform the resummation of single logarithms of the jet radius parameter R up to next-to-leading logarithmic (NLL{sub R}) accuracy. In combination with the fixed NLO calculation, we obtain NLO+NLL{sub R} results for the hadron distribution inside the jet. We present numerical results for pp→(jet h)X in the new framework, and find excellent agreement with existing LHC experimental data.

  10. Jet substructure using semi-inclusive jet functions in SCET

    International Nuclear Information System (INIS)

    Kang, Zhong-Bo; Ringer, Felix; Vitev, Ivan

    2016-01-01

    We propose a new method to evaluate jet substructure observables in inclusive jet measurements, based upon semi-inclusive jet functions in the framework of Soft Collinear Effective Theory (SCET). As a first example, we consider the jet fragmentation function, where a hadron h is identified inside a fully reconstructed jet. We introduce a new semi-inclusive fragmenting jet function G_i"h(z=ω_J/ω,z_h=ω_h/ω_J,ω_J,R,μ), which depends on the jet radius R and the large light-cone momenta of the parton ‘i’ initiating the jet (ω), the jet (ω_J), and the hadron h (ω_h). The jet fragmentation function can then be expressed as a semi-inclusive observable, in the spirit of actual experimental measurements, rather than as an exclusive one. We demonstrate the consistency of the effective field theory treatment and standard perturbative QCD calculations of this observable at next-to-leading order (NLO). The renormalization group (RG) equation for the semi-inclusive fragmenting jet function G_i"h(z,z_h,ω_J,R,μ) are also derived and shown to follow exactly the usual timelike DGLAP evolution equations for fragmentation functions. The newly obtained RG equations can be used to perform the resummation of single logarithms of the jet radius parameter R up to next-to-leading logarithmic (NLL_R) accuracy. In combination with the fixed NLO calculation, we obtain NLO+NLL_R results for the hadron distribution inside the jet. We present numerical results for pp→(jet h)X in the new framework, and find excellent agreement with existing LHC experimental data.

  11. Gigantic jets produced by an isolated tropical thunderstorm near Réunion Island

    Science.gov (United States)

    Soula, Serge; van der Velde, Oscar; Montanya, Joan; Huet, Patrice; Barthe, Christelle; Bór, József

    2011-10-01

    Five gigantic jets (GJs) have been recorded with video and photograph cameras on 7 March 2010 above an isolated tropical storm east of Réunion Island. Three of them were produced before the storm reached its coldest cloud top temperature (approximately -81°C), and two others occurred during the cloud extension. Thanks to the close distance of observation (˜50 km), the luminosity within the cloud was recorded, and the events are analyzed in unprecedented detail. The tops of the GJs are estimated between 80 and 90 km. All these GJs are accompanied by long, continuous cloud illumination, and they are preceded and followed by intermittent optical flashes from the cloud, most of time without any cloud-to-ground (CG) flash simultaneously detected, which suggests they originated mainly as intracloud discharges and without any charge transfer to Earth. The CG lightning activity is observed to cease a few tens of seconds before the jets. According to ELF data recorded at Nagycenk, Hungary, the five GJs serve to raise negative charge. Their duration ranges from 333 to 850 ms. The leading jet has the most variable duration (33-167 ms) and propagates faster at higher altitudes. The trailing jet exhibits a continuous decrease of luminosity in different parts of the jet (lower channel, transition zone and, for most events, carrot sprite-like top) and in the cloud, with possible rebrightening. The lower channels (˜20-40 km altitude) produce blue luminosity which decreases with altitude and become more and more diffuse with time. The transition zone (around 40-65 km) consists of bright red, luminous beads slowly going up (˜104 m s-1), retracing the initial leading jet channels.

  12. Deciphering jet quenching with JEWEL

    CERN Multimedia

    CERN. Geneva

    2018-01-01

    In heavy ion collisions jets arising from the fragmentation of hard quarks and gluons experience strong modifications due to final state re-scattering. This so-called jet quenching is related to the emergence of collectivity and equilibration in QCD. I will give an introduction to jet quenching and its modeling in JEWEL, a Monte Carlo implementation of a dynamical model for jet quenching. I will then discuss examples highlighting how JEWEL can be used to elucidate the physical mechanisms relevant for jet quenching.  

  13. CAMEX-4 ER-2 HIGH ALTITUDE DROPSONDE V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The CAMEX-4 ER-2 High Altitude Dropsonde dataset was collected by the ER-2 High Altitude Dropsonde System (EHAD), which used dropwinsondes fitted with Global...

  14. Aircraft Capability Management

    Science.gov (United States)

    Mumaw, Randy; Feary, Mike

    2018-01-01

    This presentation presents an overview of work performed at NASA Ames Research Center in 2017. The work concerns the analysis of current aircraft system management displays, and the initial development of an interface for providing information about aircraft system status. The new interface proposes a shift away from current aircraft system alerting interfaces that report the status of physical components, and towards displaying the implications of degradations on mission capability. The proposed interface describes these component failures in terms of operational consequences of aircraft system degradations. The research activity was an effort to examine the utility of different representations of complex systems and operating environments to support real-time decision making of off-nominal situations. A specific focus was to develop representations that provide better integrated information to allow pilots to more easily reason about the operational consequences of the off-nominal situations. The work is also seen as a pathway to autonomy, as information is integrated and understood in a form that automated responses could be developed for the off-nominal situations in the future.

  15. Aircrafts' taxi noise emission

    NARCIS (Netherlands)

    Asensio, C.; Pagan Munoz, Raul; López, J.M.

    2008-01-01

    An investigation has been conducted, with the objective of creating a database of inputs that can be used with noise prediction software, to evaluate noise of aircraft taxing movements and community noise exposure levels. The acoustic consultant can use these data with any of the software packages,

  16. Aircraft parameter estimation

    Indian Academy of Sciences (India)

    With the evolution of high performance modern aircraft and spiraling developmental and experimental costs, the importance of flight validated databases for flight control design applications and for flight simulators has increased significantly in the recent past. Ground-based and in-flight simulators are increasingly used not ...

  17. Load event: Aircraft crash

    International Nuclear Information System (INIS)

    Fritsch, H.

    1985-01-01

    The bibliography includes 48 quotations, up to the year 1983, on the following issues: Experiments and computational methods. Design load for the dimensioning of reinforced concrete buildings and components with respect to the dynamic load in the event of an aircraft crash. (orig./HP) [de

  18. Deicing System Protects General Aviation Aircraft

    Science.gov (United States)

    2007-01-01

    Kelly Aerospace Thermal Systems LLC worked with researchers at Glenn Research Center on deicing technology with assistance from the Small Business Innovation Research (SBIR) program. Kelly Aerospace acquired Northcoast Technologies Ltd., a firm that had conducted work on a graphite foil heating element under a NASA SBIR contract and developed a lightweight, easy-to-install, reliable wing and tail deicing system. Kelly Aerospace engineers combined their experiences with those of the Northcoast engineers, leading to the certification and integration of a thermoelectric deicing system called Thermawing, a DC-powered air conditioner for single-engine aircraft called Thermacool, and high-output alternators to run them both. Thermawing, a reliable anti-icing and deicing system, allows pilots to safely fly through ice encounters and provides pilots of single-engine aircraft the heated wing technology usually reserved for larger, jet-powered craft. Thermacool, an innovative electric air conditioning system, uses a new compressor whose rotary pump design runs off an energy-efficient, brushless DC motor and allows pilots to use the air conditioner before the engine even starts

  19. Jet Streams as Power Generating Electrical Energy in Libya

    International Nuclear Information System (INIS)

    Shibani, Abdelfatah H.

    2014-01-01

    The supreme wind sources are extremely huge, and according to estimations, these winds can supply Libya with great quantity of electrical energy. Among the examples of contemporary engineering technologies in this field, is to create a new generation of Airborne Wind Turbines. Scientists realized that winds near the Earth's surface are too weak to provide a regular source of energy due to the presence of aerobic swirls and obstacles, which represent a source of ground friction being the cause of weakening wind power. Some consider that the Earth's surface is a totally inappropriate place for investing wind energy. As an alternative solution, we start to think about the establishment of wind farms in another place away from the Earth's surface by developing a new type that can run within the upper-air layers, precisely at jet streams areas. In comparison with fluctuating winds blowing gently near the Earth's surface, scientists estimate that the energy of jet streams increases a thousand times than that can be gathered from the most powerful winds on high hills. To be able to provide a clear picture of the possibility of energy investment of jet streams, we shall present, across the pages of this paper, an explanation of the topic through the following aspects: How do Airborne Wind Turbines' trip start, their advantages and difficulties faced, benefits and economic feasibility, General Atmospheric Circulation and jet streams. Since Libya is among the fortunate countries in the world, through which subtropical jet streams pass, we made an analysis and follow-up of daily synoptic charts, which show jet winds' speed, direction and their altitudes for a period of 60 consecutive months starting from January 1, 2003 until December 31, 2007. Also, an analysis was made of daily observational data of jet winds recorded by Tripoli Upper-air Station during the period from the beginning of March 1987 until the end of February 1989. The paper's results summarized that jet

  20. Structure of pulsed plasma jets

    International Nuclear Information System (INIS)

    Cavolowsky, J.A.

    1987-01-01

    A pulsed plasma jet is a turbulent, inhomogeneous fluid mechanical discharge capable of initiating and enhancing combustion. Having shown the ability to ignite lean fuel mixtures, it now offers the potential for real-time control of combustion processes. This study explored the fluid-mechanical and chemical properties of such jets. The fluid-mechanical structure of the jet was examined using two optical diagnostic techniques. Self-light streak photography provided information on the motion of luminous gas particles in its core. It revealed that plasma jets behave either totally subsonic or embody a supersonic core. The turbulent, thermal evolution of the jet was explored using high-speed-laser schlieren cinematography. By examining plasma jet generators with both opaque and transparent plasma cavities, detailed information on plasma formation and jet structure, beginning with the electric arc discharge in the cavity, was obtained. These records revealed the production of thermal stratifications in the cavity that could account for the plasma particles in the jet core. After the electrical discharges ceased, the turbulent jet behaved as a self-similar plume. Molecular-beam mass spectrometry was used to determine temperature and species concentration in the jet. Both non-combustible and combustible jets were studied

  1. Aircraft Emission Scenarios Projected in Year 2015 for the NASA Technology Concept Aircraft (TCA) High Speed Civil Transport

    Science.gov (United States)

    Baughcum, Steven L.; Henderson, Stephen C.

    1998-01-01

    This report describes the development of a three-dimensional database of aircraft fuel burn and emissions (fuel burned, NOx, CO, and hydrocarbons) from projected fleets of high speed civil transports (HSCTs) on a universal airline network. Inventories for 500 and 1000 HSCT fleets, as well as the concurrent subsonic fleets, were calculated. The HSCT scenarios are calculated using the NASA technology concept airplane (TCA) and update an earlier report. These emissions inventories are available for use by atmospheric scientists conducting the Atmospheric Effects of Stratospheric Aircraft (AESA) modeling studies. Fuel burned and emissions of nitrogen oxides (NOx as NO2), carbon monoxide, and hydrocarbons have been calculated on a 1 degree latitude x 1 degree longitude x 1 kilometer pressure altitude grid and delivered to NASA as electronic files.

  2. Overview of NASA Electrified Aircraft Propulsion Research for Large Subsonic Transports

    Science.gov (United States)

    Jansen, Ralph H.; Bowman, Cheryl; Jankovsky, Amy; Dyson, Rodger; Felder, James L.

    2017-01-01

    NASA is investing in Electrified Aircraft Propulsion (EAP) research as part of the portfolio to improve the fuel efficiency, emissions, and noise levels in commercial transport aircraft. Turboelectric, partially turboelectric, and hybrid electric propulsion systems are the primary EAP configurations being evaluated for regional jet and larger aircraft. The goal is to show that one or more viable EAP concepts exist for narrow body aircraft and mature tall-pole technologies related to those concepts. A summary of the aircraft system studies, technology development, and facility development is provided. The leading concept for mid-term (2035) introduction of EAP for a single aisle aircraft is a tube and wing, partially turbo electric configuration (STARC-ABL), however other viable configurations exist. Investments are being made to raise the TRL level of light weight, high efficiency motors, generators, and electrical power distribution systems as well as to define the optimal turbine and boundary layer ingestion systems for a mid-term tube and wing configuration. An electric aircraft power system test facility (NEAT) is under construction at NASA Glenn and an electric aircraft control system test facility (HEIST) is under construction at NASA Armstrong. The correct building blocks are in place to have a viable, large plane EAP configuration tested by 2025 leading to entry into service in 2035 if the community chooses to pursue that goal.

  3. Optic neuropathy following an altitude exposure.

    Science.gov (United States)

    Steigleman, Allan; Butler, Frank; Chhoeu, Austin; O'Malley, Timothy; Bower, Eric; Giebner, Stephen

    2003-09-01

    This case report describes a 20-yr-old man who presented with retro-orbital pain and blurred vision in his left eye 3 wk after an altitude exposure in a hypobaric chamber. He was found to have significant deficits in color vision and visual fields consistent with an optic neuropathy in his left eye. The patient was diagnosed with decompression sickness and treated with hyperbaric oxygen with a U.S. Navy Treatment Table VI. All signs and symptoms resolved with a single hyperbaric oxygen treatment but recurred. A head MRI revealed a left frontoethmoid sinus opacity. A concomitant sinusitis was diagnosed. The patient had full resolution of symptoms after a total of four hyperbaric oxygen treatments and antibiotic therapy at 6-wk follow-up. Although a para-infectious etiology for this patient's optic neuropathy cannot be excluded, his history of altitude exposure and significant, rapid response to hyperbaric oxygen treatment strongly implies decompression sickness in this case.

  4. Spatial and temporal distribution of ionospheric currents-4: altitude ...

    African Journals Online (AJOL)

    (a) The continuous distribution of current density model reproduces the altitude distribution parameters of EEJ current density very well, (b) the altitude distribution parameters of EEJ current density in India and Peru are not significantly different and (c) The altitude distribution parameters of EEJ current density from rockets ...

  5. Neutral barium cloud evolution at different altitudes

    International Nuclear Information System (INIS)

    Li Lei; Xu Ronglan

    2002-01-01

    Considering the joint effects of diffusion, collision, oxidation and photoionization, the authors study the evolution of the barium cloud at different altitudes in the space plasma active experiment. The results present the variation of the loss rate, number density distribution and brightness of the barium cloud over the range from 120 to 260 km. This can be divided into oxidation, oxidation plus photoionization and photoionization regions

  6. Guide to Altitude Decompression Sickness Research

    Science.gov (United States)

    2010-05-01

    fitness flight gender growth helium hormone human hyperbaric hypobaric hypoxia incidence injury interface interruption intra in-vitro isobaric male...exposure in hypobaric chambers and, due to its omission of other training, was not adequate for any other use. The two items required prior to...were kept in the contractor lab. 3. Hypobaric exposure records (Research Chamber Flight Records, including AF Forms 361) were kept by Altitude and

  7. DeepJet: a deep-learned multiclass jet-tagger for slim and fat jets

    CERN Multimedia

    CERN. Geneva; Qu, Huilin; Stoye, Markus; Kieseler, Jan; Verzetti, Mauro

    2018-01-01

    We present a customized neural network architecture for both, slim and fat jet tagging. It is based on the idea to keep the concept of physics objects, like particle flow particles, as a core element of the network architecture. The deep learning algorithm works for most of the common jet classes, i.e. b, c, usd and gluon jets for slim jets and W, Z, H, QCD and top classes for fat jets. The developed architecture promising gains in performance as shown in simulation of the CMS collaboration. Currently the tagger is under test in real data in the CMS experiment.

  8. HIGH ALTITUDES EFFECTS ON HEMATOLOGIC BLOOD PARAMETERS

    Directory of Open Access Journals (Sweden)

    Hasim Rushiti

    2015-05-01

    Full Text Available The approach and the objective of this experiment are consistent with the determination of changes of blood parameters after the stay of the students at an altitude of 1800-2300 meters, for a ten-day long ski course. In this paper are included a total of 64 students of the Faculty of Sport Sciences in Prishtina, of the age group of 19-25 (the average age is 21. All students previously have undergone a medical check for TA, arterial pulse and respiratory rate. In particular, the health situation is of subjects was examined, then, all students, at the same time, gave blood for analysis. In this experiment, three main hematologic parameters were taken in consideration: such as hemoglobin, hematocrit and red blood cells. The same analyses were carried out after the 10-day stay at a high altitude. The results of the experiment have shown significant changes after the ten-day stay at high altitude, despite the previous results that show changes only after the twenty-day stay in such elevations.

  9. Altitude variation of cosmic-ray neutrons

    International Nuclear Information System (INIS)

    Nakamura, T.; Uwamino, Y.; Ohkubo, T.; Hara, A.

    1987-01-01

    The altitude variation of the cosmic-ray neutron energy spectrum and the dose equivalent rate was measured at an average geomagnetic latitude of 24 degrees N by using the high-efficiency multi-sphere neutron spectrometer and neutron dose-equivalent counter developed by the authors. The data were obtained from a 2-h flight over Japan on 27 February 1985. The neutron energy spectra measured at sea level and at altitudes of 4880 m and at 11,280 m were compared with the calculated spectra of O'Brien and with other experimental spectra, and they are in moderately good agreement with them. The dose equivalent rate increases according to a quadratic curve up to about 6000 m and then increases linearly between 6000 m and 11,280 m. The dependence of dose equivalent rates at sea level and at an altitude of 12,500 m on geomagnetic latitude also is given by referring to other experimental results

  10. OPTIMAL AIRCRAFT TRAJECTORIES FOR SPECIFIED RANGE

    Science.gov (United States)

    Lee, H.

    1994-01-01

    For an aircraft operating over a fixed range, the operating costs are basically a sum of fuel cost and time cost. While minimum fuel and minimum time trajectories are relatively easy to calculate, the determination of a minimum cost trajectory can be a complex undertaking. This computer program was developed to optimize trajectories with respect to a cost function based on a weighted sum of fuel cost and time cost. As a research tool, the program could be used to study various characteristics of optimum trajectories and their comparison to standard trajectories. It might also be used to generate a model for the development of an airborne trajectory optimization system. The program could be incorporated into an airline flight planning system, with optimum flight plans determined at takeoff time for the prevailing flight conditions. The use of trajectory optimization could significantly reduce the cost for a given aircraft mission. The algorithm incorporated in the program assumes that a trajectory consists of climb, cruise, and descent segments. The optimization of each segment is not done independently, as in classical procedures, but is performed in a manner which accounts for interaction between the segments. This is accomplished by the application of optimal control theory. The climb and descent profiles are generated by integrating a set of kinematic and dynamic equations, where the total energy of the aircraft is the independent variable. At each energy level of the climb and descent profiles, the air speed and power setting necessary for an optimal trajectory are determined. The variational Hamiltonian of the problem consists of the rate of change of cost with respect to total energy and a term dependent on the adjoint variable, which is identical to the optimum cruise cost at a specified altitude. This variable uniquely specifies the optimal cruise energy, cruise altitude, cruise Mach number, and, indirectly, the climb and descent profiles. If the optimum

  11. Effects of Low-Altitude Aircraft Overflights on Domestic Turkey Poults

    Science.gov (United States)

    1990-06-30

    density rearing systems, too much heat, nutritional and mineral deficiencies, and irritation from parasites. If birds pick on one another or scratch...influence of flight noise on mortality and productivity in broiler chickens and in hen behavior," Inaugural Dissertation for Animal Hygiene at the...and were housed in two 2 x 6 m covered chicken wire pens at the experimental site (see Figure 2-4). Originally, they were to have been acclimatized

  12. Unmanned Aircraft Systems Traffic Management (UTM): Safely Enabling UAS Operations in Low-Altitude Airspace

    Science.gov (United States)

    Homola, Jeffrey; Owens, Brandon

    2017-01-01

    This is a presentation for a Cisco Internet of Things (IoT) Systems Engineering Virtual Training (SEVT) event. The presentation provides an overview of the UTM concept, architecture, flight test events, and lessons learned. Networking hardware used in support of flight tests is also described.

  13. Validation of modelling the radiation exposure due to solar particle events at aircraft altitudes

    Czech Academy of Sciences Publication Activity Database

    Beck, P.; Bartlett, D. T.; Bilski, P.; Dyer, C.; Fluckiger, E.; Fuller, N.; Lantos, P.; Reitz, G.; Ruhm, W.; Spurný, František; Taylor, G.; Trompier, F.; Wissmann, F.

    2008-01-01

    Roč. 131, č. 1 (2008), s. 51-58 ISSN 0144-8420. [Annual Meeting of the European-Radiation-Dosimetry-Group (EURADOS). Paris, 21.01.2008-25.01.2008] R&D Projects: GA MŠk 1P05OC032 Grant - others:Evropské společenství(XE) ILSRA - 2004 - 248 Institutional research plan: CEZ:AV0Z10480505 Keywords : on-board airplanes * cosmic radiation * simulations Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 0.951, year: 2008

  14. Flexible Twist for Pitch Control in a High Altitude Long Endurance Aircraft with Nonlinear Response

    Science.gov (United States)

    2008-12-01

    Kimler [28] accomplished a cursory examination of laminate ply orientation. He found only a small improvement was made with fiber direction...aerodynamic transfer function, H , relates the aerodynamic forces,  aF , to the structural deformation, ( )x t through the convolution integral...structural deformation, ( )x t through the convolution integral,           . 0 , t V a bF x t x t q H t x d           (3.4

  15. Effects of simulated altitude on blood glucose meter performance: implications for in-flight blood glucose monitoring.

    Science.gov (United States)

    Olateju, Tolu; Begley, Joseph; Flanagan, Daniel; Kerr, David

    2012-07-01

    Most manufacturers of blood glucose monitoring equipment do not give advice regarding the use of their meters and strips onboard aircraft, and some airlines have blood glucose testing equipment in the aircraft cabin medical bag. Previous studies using older blood glucose meters (BGMs) have shown conflicting results on the performance of both glucose oxidase (GOX)- and glucose dehydrogenase (GDH)-based meters at high altitude. The aim of our study was to evaluate the performance of four new-generation BGMs at sea level and at a simulated altitude equivalent to that used in the cabin of commercial aircrafts. Blood glucose measurements obtained by two GDH and two GOX BGMs at sea level and simulated altitude of 8000 feet in a hypobaric chamber were compared with measurements obtained using a YSI 2300 blood glucose analyzer as a reference method. Spiked venous blood samples of three different glucose levels were used. The accuracy of each meter was determined by calculating percentage error of each meter compared with the YSI reference and was also assessed against standard International Organization for Standardization (ISO) criteria. Clinical accuracy was evaluated using the consensus error grid method. The percentage (standard deviation) error for GDH meters at sea level and altitude was 13.36% (8.83%; for meter 1) and 12.97% (8.03%; for meter 2) with p = .784, and for GOX meters was 5.88% (7.35%; for meter 3) and 7.38% (6.20%; for meter 4) with p = .187. There was variation in the number of time individual meters met the standard ISO criteria ranging from 72-100%. Results from all four meters at both sea level and simulated altitude fell within zones A and B of the consensus error grid, using YSI as the reference. Overall, at simulated altitude, no differences were observed between the performance of GDH and GOX meters. Overestimation of blood glucose concentration was seen among individual meters evaluated, but none of the results obtained would have resulted in

  16. Correction of static pressure on a research aircraft in accelerated flight using differential pressure measurements

    Directory of Open Access Journals (Sweden)

    A. R. Rodi

    2012-11-01

    Full Text Available A method is described that estimates the error in the static pressure measurement on an aircraft from differential pressure measurements on the hemispherical surface of a Rosemount model 858AJ air velocity probe mounted on a boom ahead of the aircraft. The theoretical predictions for how the pressure should vary over the surface of the hemisphere, involving an unknown sensitivity parameter, leads to a set of equations that can be solved for the unknowns – angle of attack, angle of sideslip, dynamic pressure and the error in static pressure – if the sensitivity factor can be determined. The sensitivity factor was determined on the University of Wyoming King Air research aircraft by comparisons with the error measured with a carefully designed sonde towed on connecting tubing behind the aircraft – a trailing cone – and the result was shown to have a precision of about ±10 Pa over a wide range of conditions, including various altitudes, power settings, and gear and flap extensions. Under accelerated flight conditions, geometric altitude data from a combined Global Navigation Satellite System (GNSS and inertial measurement unit (IMU system are used to estimate acceleration effects on the error, and the algorithm is shown to predict corrections to a precision of better than ±20 Pa under those conditions. Some limiting factors affecting the precision of static pressure measurement on a research aircraft are discussed.

  17. An Engineering Method of Civil Jet Requirements Validation Based on Requirements Project Principle

    Science.gov (United States)

    Wang, Yue; Gao, Dan; Mao, Xuming

    2018-03-01

    A method of requirements validation is developed and defined to meet the needs of civil jet requirements validation in product development. Based on requirements project principle, this method will not affect the conventional design elements, and can effectively connect the requirements with design. It realizes the modern civil jet development concept, which is “requirement is the origin, design is the basis”. So far, the method has been successfully applied in civil jet aircraft development in China. Taking takeoff field length as an example, the validation process and the validation method of the requirements are detailed introduced in the study, with the hope of providing the experiences to other civil jet product design.

  18. Model analysis of the chemical conversion of exhaust species in the expanding plumes of subsonic aircraft

    Energy Technology Data Exchange (ETDEWEB)

    Moellhoff, M.; Hendricks, J.; Lippert, E.; Petry, H. [Koeln Univ. (Germany). Inst. fuer Geophysik und Meteorologie; Sausen, R. [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Oberpfaffenhofen (Germany). Inst. fuer Physik der Atmosphaere

    1997-12-31

    A box model and two different one-dimensional models are used to investigate the chemical conversion of exhaust species in the dispersing plume of a subsonic aircraft flying at cruise altitude. The effect of varying daytime of release as well as the impact of changing dispersion time is studied with special respect to the aircraft induced O{sub 3} production. Effective emission amounts for consideration in mesoscale and global models are calculated. Simulations with modified photolysis rates are performed to show the sensitivity of the photochemistry to the occurrence of cirrus clouds. (author) 8 refs.

  19. Automated meteorological data from commercial aircraft via satellite: Present experience and future implications

    Science.gov (United States)

    Steinberg, R.

    1978-01-01

    A low-cost communications system to provide meteorological data from commercial aircraft, in neat real-time, on a fully automated basis has been developed. The complete system including the low profile antenna and all installation hardware weighs 34 kg. The prototype system was installed on a B-747 aircraft and provided meteorological data (wind angle and velocity, temperature, altitude and position as a function of time) on a fully automated basis. The results were exceptional. This concept is expected to have important implications for operational meteorology and airline route forecasting.

  20. Automated meteorological data from commercial aircraft via satellite - Present experience and future implications

    Science.gov (United States)

    Steinberg, R.

    1978-01-01

    The National Aeronautics and Space Administration has developed a low-cost communications system to provide meteorological data from commercial aircraft, in near real-time, on a fully automated basis. The complete system including the low profile antenna and all installation hardware weighs 34 kg. The prototype system has been installed on a Pan American B-747 aircraft and has been providing meteorological data (wind angle and velocity, temperature, altitude and position as a function of time) on a fully automated basis for the past several months. The results have been exceptional. This concept is expected to have important implications for operational meteorology and airline route forecasting.

  1. Model analysis of the chemical conversion of exhaust species in the expanding plumes of subsonic aircraft

    Energy Technology Data Exchange (ETDEWEB)

    Moellhoff, M; Hendricks, J; Lippert, E; Petry, H [Koeln Univ. (Germany). Inst. fuer Geophysik und Meteorologie; Sausen, R [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Oberpfaffenhofen (Germany). Inst. fuer Physik der Atmosphaere

    1998-12-31

    A box model and two different one-dimensional models are used to investigate the chemical conversion of exhaust species in the dispersing plume of a subsonic aircraft flying at cruise altitude. The effect of varying daytime of release as well as the impact of changing dispersion time is studied with special respect to the aircraft induced O{sub 3} production. Effective emission amounts for consideration in mesoscale and global models are calculated. Simulations with modified photolysis rates are performed to show the sensitivity of the photochemistry to the occurrence of cirrus clouds. (author) 8 refs.

  2. Jet photoproduction at HERA

    International Nuclear Information System (INIS)

    Frixione, S.

    1997-01-01

    We compute various kinematical distributions for one-jet and two-jet inclusive photoproduction at HERA. Our results are accurate to next-to-leading order in QCD. We use the subtraction method for the cancellation of infrared singularities. We perform a thorough study of the reliability of QCD predictions; in particular, we consider the scale dependence of our results and discuss the cases when the perturbative expansion might break down. We also deal with the problem of the experimental definition of the pointlike and hadronic components of the incident photon, and briefly discuss the sensitivity of QCD predictions upon the input parameters of the calculation, like α S and the parton densities. (orig.)

  3. QCD and jets

    International Nuclear Information System (INIS)

    Munehisa, Tomo

    1990-01-01

    We present a review on the parton shower in e + e - annihilation. Also we discuss the next-to-leading-logarithmic parton shower. We emphasize that this new model provides a useful tool for the determinations of Λ MS from jet distributions. Analysis by the new model gives us Λ MS = 0.235±0.052 GeV from data of PETRA, PEP and TRISTAN. (author)

  4. Active control of continuous air jet with bifurcated synthetic jets

    Directory of Open Access Journals (Sweden)

    Dančová Petra

    2017-01-01

    Full Text Available The synthetic jets (SJs have many significant applications and the number of applications is increasing all the time. In this research the main focus is on the primary flow control which can be used effectively for the heat transfer increasing. This paper deals with the experimental research of the effect of two SJs worked in the bifurcated mode used for control of an axisymmetric air jet. First, the control synthetic jets were measured alone. After an adjustment, the primary axisymmetric jet was added in to the system. For comparison, the primary flow without synthetic jets control was also measured. All experiments were performed using PIV method whereby the synchronization between synthetic jets and PIV system was necessary to do.

  5. Rationale and operational plan for a U.S. high-altitude magnetic survey

    Science.gov (United States)

    Hildenbrand, Thomas G.; Acuna, Mario; Bracken, Robert E.; Hardwick, Doug; Hinze, William J.; Keller, Gordon R.; Phillips, Jeff; Roest, Walter

    2002-01-01

    On August 8, 2002, twenty-one scientists from the federal, private and academic sectors met at a workshop in Denver, Co., to discuss the feasibility of collecting magnetic anomaly data on a Canberra aircraft (Figure 1). The need for this 1-day workshop arose because of an exciting and cost-effective opportunity to collect invaluable magnetic anomaly data during a Canberra mission over the U.S. in 2003 and 2004. High Altitude Mapping Missions (HAMM) is currently planning a mission to collect Interferometric Synthetic Aperture Radar (IFSAR) imagery at an altitude of about 15 km and with a flight-line spacing of about 18 km over the conterminous U.S. and Alaska. The additional collection of total and vector magnetic field data would represent a secondary mission objective (i.e., a "piggy-back" magnetometer system). Because HAMM would fund the main flight costs of the mission, the geomagnetic community would obtain invaluable magnetic data at a nominal cost. These unique data would provide new insights on fundamental tectonic and thermal processes and give a new view of the structural and lithologic framework of the crust and possibly the upper mantle. This document highlights: (1) the reasons to conduct this national survey and (2) a preliminary operational plan to collect high-altitude magnetic data of a desired quality and for the expected resources. Although some operational plan issues remain to be resolved, the important conclusions of the workshop are that the Canberra is a very suitable platform to measure the magnetic field and that the planned mission will result in quality high-altitude magnetic data to greatly expand the utility of our national magnetic database.

  6. Preacclimatization in hypoxic chambers for high altitude sojourns.

    Science.gov (United States)

    Küpper, Thomas E A H; Schöffl, Volker

    2010-09-01

    Since hypoxic chambers are more and more available, they are used for preacclimatization to prepare for sojourns at high altitude. Since there are different protocols and the data differ, there is no general consensus about the standard how to perform preacclimatization by simulated altitude. The paper reviews the different types of exposure and focuses on the target groups which may benefit from preacclimatization. Since data about intermittent hypoxia for some hours per day to reduce the incidence of acute mountain sickness differ, it is suggested to perform preacclimatization by sleeping some nights at a simulated altitude which follows the altitude profile of the "gold standard" for high altitude acclimatization.

  7. Jet operated heat pump

    International Nuclear Information System (INIS)

    Collard, T.H.

    1982-01-01

    A jet pump system is shown that utilizes waste heat to provide heating and/or cooling. Waste heat diverted through a boiler causes a refrigerant to evaporate and expand for supersonic discharge through a nozzle thereby creating a vacuum in an evaporator coil. The vacuum draws the refrigerant in a gaseous state into a condensing section of a jet pump along with refrigerant from a reservoir in a subcooled liquid form. This causes condensation of the gas in a condensation section of the jet pump, while moving at constant velocity. The change in momentum of the fluid overcomes the system high side pressure. Some of the condensate is cooled by a subcooler. Refrigerant in a subcooled liquid state from the subcooler is fed back into the evaporator and the condensing section with an adequate supply being insured by the reservoir. The motive portion of the condensate is returned to the boiler sans subcooling. By proper valving start-up is insured, as well as the ability to switch from heating to cooling

  8. Greenland plateau jets

    Directory of Open Access Journals (Sweden)

    George William Kent Moore

    2013-08-01

    Full Text Available The high ice-covered topography of Greenland represents a significant barrier to atmospheric flow and, as a direct and indirect result, it plays a crucial role in the coupled climate system. The wind field over Greenland is important in diagnosing regional weather and climate, thereby providing information on the mass balance of the ice sheet as well as assisting in the interpretation of ice core data. Here, we identify a number of hitherto unrecognised features of the three-dimensional wind field over Greenland; including a 2500-km-long jet along the central ice sheet's western margin that extends from the surface into the middle-troposphere, as well as a similar but smaller scale and less intense feature along its eastern margin. We refer to these features as Greenland Plateau Jets. The jets are coupled to the downslope katabatic flow and we argue that they are maintained by the zonal temperature gradients associated with the strong temperature inversion over the central ice sheet. Their importance for Greenland's regional climate is discussed.

  9. On the dominant noise components of tactical aircraft: Laboratory to full scale

    Science.gov (United States)

    Tam, Christopher K. W.; Aubert, Allan C.; Spyropoulos, John T.; Powers, Russell W.

    2018-05-01

    This paper investigates the dominant noise components of a full-scale high performance tactical aircraft. The present study uses acoustic measurements of the exhaust jet from a single General Electric F414-400 turbofan engine installed in a Boeing F/A-18E Super Hornet aircraft operating from flight idle to maximum afterburner. The full-scale measurements are to the ANSI S12.75-2012 standard employing about 200 microphones. By comparing measured noise spectra with those from hot supersonic jets observed in the laboratory, the dominant noise components specific to the F/A-18E aircraft at different operating power levels are identified. At intermediate power, it is found that the dominant noise components of an F/A-18E aircraft are essentially the same as those of high temperature supersonic laboratory jets. However, at military and afterburner powers, there are new dominant noise components. Their characteristics are then documented and analyzed. This is followed by an investigation of their origin and noise generation mechanisms.

  10. Aircraft engines. IV

    Energy Technology Data Exchange (ETDEWEB)

    Ruffles, P C

    1989-01-01

    Configurational design and thermodynamic performance gain trends are projected into the next 50 years, in view of the growing interest of aircraft manufacturers in both larger and more efficient high-bypass turbofan engines for subsonic flight and variable cycle engines for supersonic flight. Ceramic- and metal-matrix composites are envisioned as the key to achievement of turbine inlet temperatures 300 C higher than the 1400 C which is characteristic of the state-of-the-art, with the requisite high stiffness, strength, and low density. Such fiber-reinforced materials can be readily tailored to furnish greatest strength in a specific direction of loading. Large, low-density engines are critical elements of future 1000-seat aircraft.

  11. Aircraft engine pollution reduction.

    Science.gov (United States)

    Rudey, R. A.

    1972-01-01

    The effect of engine operation on the types and levels of the major aircraft engine pollutants is described and the major factors governing the formation of these pollutants during the burning of hydrocarbon fuel are discussed. Methods which are being explored to reduce these pollutants are discussed and their application to several experimental research programs are pointed out. Results showing significant reductions in the levels of carbon monoxide, unburned hydrocarbons, and oxides of nitrogen obtained from experimental combustion research programs are presented and discussed to point out potential application to aircraft engines. An experimental program designed to develop and demonstrate these and other advanced, low pollution combustor design methods is described. Results that have been obtained to date indicate considerable promise for reducing advanced engine exhaust pollutants to levels significantly below current engines.

  12. Aircraft Design Software

    Science.gov (United States)

    1997-01-01

    Successful commercialization of the AirCraft SYNThesis (ACSYNT) tool has resulted in the creation of Phoenix Integration, Inc. ACSYNT has been exclusively licensed to the company, an outcome of a seven year, $3 million effort to provide unique software technology to a focused design engineering market. Ames Research Center formulated ACSYNT and in working with the Virginia Polytechnic Institute CAD Laboratory, began to design and code a computer-aided design for ACSYNT. Using a Joint Sponsored Research Agreement, Ames formed an industry-government-university alliance to improve and foster research and development for the software. As a result of the ACSYNT Institute, the software is becoming a predominant tool for aircraft conceptual design. ACSYNT has been successfully applied to high- speed civil transport configuration, subsonic transports, and supersonic fighters.

  13. Residual Stress Analysis of Aircraft Part using Neutron Beam

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Eun Joo; Seong, Baek Seok; Sim, Cheul Muu [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-05-15

    A precise measurement of the residual stress magnitude and distribution is an important factor to evaluate the lifetime or safety of the materials, because the residual stress affects the material properties, such as the strength, fatigue, etc. In the case of a fighter jet, the lifetime and safety of the parts of the landing gear are more important than that of a passenger airplane because of its frequent take offs and landings. In particular in the case of training a fighter jet, a precise evaluation of life time for the parts of the landing gear is strongly required for economic reason. In this study, the residual stress of a part of the landing gear of the training fighter jet which is used to fix the landing gear to the aircraft body was investigated. The part was used for 2000 hours of flight, which corresponds to 10 years. During this period, the fighter jet normally takes off and lands more than 2000 times. These frequent take off and landing can generate residual stress and cause a crack in the part. By measuring the neutron diffraction peaks, we evaluated the residual stress of the landing gear part

  14. High-Altitude Illnesses: Physiology, Risk Factors, Prevention, and Treatment

    Directory of Open Access Journals (Sweden)

    Andrew T. Taylor

    2011-01-01

    Full Text Available High-altitude illnesses encompass the pulmonary and cerebral syndromes that occur in non-acclimatized individuals after rapid ascent to high altitude. The most common syndrome is acute mountain sickness (AMS which usually begins within a few hours of ascent and typically consists of headache variably accompanied by loss of appetite, nausea, vomiting, disturbed sleep, fatigue, and dizziness. With millions of travelers journeying to high altitudes every year and sleeping above 2,500 m, acute mountain sickness is a wide-spread clinical condition. Risk factors include home elevation, maximum altitude, sleeping altitude, rate of ascent, latitude, age, gender, physical condition, intensity of exercise, pre-acclimatization, genetic make-up, and pre-existing diseases. At higher altitudes, sleep disturbances may become more profound, mental performance is impaired, and weight loss may occur. If ascent is rapid, acetazolamide can reduce the risk of developing AMS, although a number of high-altitude travelers taking acetazolamide will still develop symptoms. Ibuprofen can be effective for headache. Symptoms can be rapidly relieved by descent, and descent is mandatory, if at all possible, for the management of the potentially fatal syndromes of high-altitude pulmonary and cerebral edema. The purpose of this review is to combine a discussion of specific risk factors, prevention, and treatment options with a summary of the basic physiologic responses to the hypoxia of altitude to provide a context for managing high-altitude illnesses and advising the non-acclimatized high-altitude traveler.

  15. Aircraft Weather Mitigation for the Next Generation Air Transportation System

    Science.gov (United States)

    Stough, H. Paul, III

    2007-01-01

    Atmospheric effects on aviation are described by Mahapatra (1999) as including (1) atmospheric phenomena involving air motion - wind shear and turbulence; (2) hydrometeorological phenomena - rain, snow and hail; (3) aircraft icing; (4) low visibility; and (5) atmospheric electrical phenomena. Aircraft Weather Mitigation includes aircraft systems (e.g. airframe, propulsion, avionics, controls) that can be enacted (by a pilot, automation or hybrid systems) to suppress and/or prepare for the effects of encountered or unavoidable weather or to facilitate a crew operational decision-making process relative to weather. Aircraft weather mitigation can be thought of as a continuum (Figure 1) with the need to avoid all adverse weather at one extreme and the ability to safely operate in all weather conditions at the other extreme. Realistic aircraft capabilities fall somewhere between these two extremes. The capabilities of small general aviation aircraft would be expected to fall closer to the "Avoid All Adverse Weather" point, and the capabilities of large commercial jet transports would fall closer to the "Operate in All Weather Conditions" point. The ability to safely operate in adverse weather conditions is dependent upon the pilot s capabilities (training, total experience and recent experience), the airspace in which the operation is taking place (terrain, navigational aids, traffic separation), the capabilities of the airport (approach guidance, runway and taxiway lighting, availability of air traffic control), as well as the capabilities of the airplane. The level of mitigation may vary depending upon the type of adverse weather. For example, a small general aviation airplane may be equipped to operate "in the clouds" without outside visual references, but not be equipped to prevent airframe ice that could be accreted in those clouds.

  16. High Altitude Aerial Natural Gas Leak Detection System

    Energy Technology Data Exchange (ETDEWEB)

    Richard T. Wainner; Mickey B. Frish; B. David Green; Matthew C. Laderer; Mark G. Allen; Joseph R. Morency

    2006-12-31

    The objective of this program was to develop and demonstrate a cost-effective and power-efficient advanced standoff sensing technology able to detect and quantify, from a high-altitude (> 10,000 ft) aircraft, natural gas leaking from a high-pressure pipeline. The advanced technology is based on an enhanced version of the Remote Methane Leak Detector (RMLD) platform developed previously by Physical Sciences Inc. (PSI). The RMLD combines a telecommunications-style diode laser, fiber-optic components, and low-cost DSP electronics with the well-understood principles of Wavelength Modulation Spectroscopy (WMS), to indicate the presence of natural gas located between the operator and a topographic target. The transceiver transmits a laser beam onto a topographic target and receives some of the laser light reflected by the target. The controller processes the received light signal to deduce the amount of methane in the laser's path. For use in the airborne platform, we modified three aspects of the RMLD, by: (1) inserting an Erbium-doped optical fiber laser amplifier to increase the transmitted laser power from 10 mW to 5W; (2) increasing the optical receiver diameter from 10 cm to 25 cm; and (3) altering the laser wavelength from 1653 nm to 1618 nm. The modified RMLD system provides a path-integrated methane concentration sensitivity {approx}5000 ppm-m, sufficient to detect the presence of a leak from a high capacity transmission line while discriminating against attenuation by ambient methane. In ground-based simulations of the aerial leak detection scenario, we demonstrated the ability to measure methane leaks within the laser beam path when it illuminates a topographic target 2000 m away. We also demonstrated simulated leak detection from ranges of 200 m using the 25 cm optical receiver without the fiber amplifier.

  17. Combat Aircraft Maneuverability.

    Science.gov (United States)

    1981-12-01

    rodynamique, propulsion, rdsistance den structures, etc ... - lea m~thodes d’essaia an soufflerie, aur banca au aol, sur simulateurs. A un niveau de synthbse...Dunstan Graham, "Aircraft Dynamics and Automatic Control," Princeton University Press , Princeton, N.J., 1973. 9. Hoh, Roger H., Thomas T. Myers...discussion of the roll coupling problem" Progress in Aerospace Sciences, Vol 15, Pergamon Press , Oxford 1974 17-8 (6] R.W. KLOPPENSTEIN "Zeroes of

  18. Multiple Jets at the LHC with High Energy Jets

    DEFF Research Database (Denmark)

    Andersen, Jeppe Rosenkrantz; Smillie, Jennifer M.

    2011-01-01

    We present a flexible Monte Carlo implementation of the perturbative framework of High Energy Jets, describing multi-jet events at hadron colliders. The description includes a resummation which ensures leading logarithmic accuracy for large invariant mass between jets, and is matched to tree......-level accuracy for multiplicities up to 4 jets. The resummation includes all-order hard corrections, which become important for increasing centre-of-mass energy of the hadronic collision. We discuss observables relevant for confronting the perturbative framework with 7 TeV data from the LHC, and the impact...

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

    Science.gov (United States)

    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. Aircraft gas turbines

    Energy Technology Data Exchange (ETDEWEB)

    Sekido, T [Ishikawajima-Harima Heavy Industries, Co. Ltd., Tokyo (Japan)

    1994-03-01

    Current developmental activities of aircraft gas turbines in Japan are reviewed. V2500-A5 engine with thrust of 30,000 LBF is scheduled to be used for real aircraft in 1994, and intensive developmental activities are also proceeding in larger engines over 90,000 LBF. Recently, developmental programs of engines for 75-100 seat aircraft have been actively discussed, and Japanese engine makers are having discussions towards international collaboration. Such engines will be high bypass turbofans of 12,000-22,000 LBF. Development of SST/HST engines in a speed range from subsonic to Mach 5 is under the initiative of the Agency of Industrial Science and Technology. The Technical Research and Development Institute of Japan, Defence Agency achieved the target thrust of 3.4 tons in the small turbofan engine program, and the small turboshaft engine for small helicopters is also under development. Both National Aerospace Laboratory (NAL) and Institute of Space and Aeronautical Science (ISAS) are now conducting the research programs on turbo-ramjet engines under a component test phase. 1 fig.