WorldWideScience

Sample records for aircraft simulation role

  1. Delivering better power: the role of simulation in reducing the environmental impact of aircraft engines.

    Science.gov (United States)

    Menzies, Kevin

    2014-08-13

    The growth in simulation capability over the past 20 years has led to remarkable changes in the design process for gas turbines. The availability of relatively cheap computational power coupled to improvements in numerical methods and physical modelling in simulation codes have enabled the development of aircraft propulsion systems that are more powerful and yet more efficient than ever before. However, the design challenges are correspondingly greater, especially to reduce environmental impact. The simulation requirements to achieve a reduced environmental impact are described along with the implications of continued growth in available computational power. It is concluded that achieving the environmental goals will demand large-scale multi-disciplinary simulations requiring significantly increased computational power, to enable optimization of the airframe and propulsion system over the entire operational envelope. However even with massive parallelization, the limits imposed by communications latency will constrain the time required to achieve a solution, and therefore the position of such large-scale calculations in the industrial design process.

  2. Aircraft Simulators and Pilot Training.

    Science.gov (United States)

    Caro, Paul W.

    Flight simulators are built as realistically as possible, presumably to enhance their training value. Yet, their training value is determined by the way they are used. Traditionally, simulators have been less important for training than have aircraft, but they are currently emerging as primary pilot training vehicles. This new emphasis is an…

  3. Simulation of Aircraft Sortie Generation Under an Autonomic Logistics System

    Science.gov (United States)

    2016-12-01

    SIMULATION OF AIRCRAFT SORTIE GENERATION UNDER AN AUTONOMIC LOGISTICS SYSTEM THESIS Gunduz...Government. AFIT-ENS-MS-16-D-052 SIMULATION OF AIRCRAFT SORTIE GENERATION UNDER AN AUTONOMIC LOGISTICS SYSTEM THESIS Presented to...DISTRIBUTION UNLIMITED. AFIT-ENS-MS-16-D-052 SIMULATION OF AIRCRAFT SORTIE GENERATION UNDER AN AUTONOMIC LOGISTICS SYSTEM THESIS

  4. Piloted Aircraft Environment Simulation Techniques

    Science.gov (United States)

    1978-04-01

    be led by disciplinary specialists, should be shared to some degree by all members of the team so that team members influence each other to the maximum...cause some observers to fall over (to prevent this, most 3600 movie exhibits, like the one in Disneyland , providea support to hang onto). This sensation...started all over again. So in a simulation, you might try maneuvers that are a little bit out of the ordinary and performancewise, you might try to

  5. Aircraft vulnerability analysis by modelling and simulation

    CSIR Research Space (South Africa)

    Willers, CJ

    2014-09-01

    Full Text Available 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...

  6. Numerical simulation and experimental validation of aircraft ground deicing model

    Directory of Open Access Journals (Sweden)

    Bin Chen

    2016-05-01

    Full Text Available Aircraft ground deicing plays an important role of guaranteeing the aircraft safety. In practice, most airports generally use as many deicing fluids as possible to remove the ice, which causes the waste of the deicing fluids and the pollution of the environment. Therefore, the model of aircraft ground deicing should be built to establish the foundation for the subsequent research, such as the optimization of the deicing fluid consumption. In this article, the heat balance of the deicing process is depicted, and the dynamic model of the deicing process is provided based on the analysis of the deicing mechanism. In the dynamic model, the surface temperature of the deicing fluids and the ice thickness are regarded as the state parameters, while the fluid flow rate, the initial temperature, and the injection time of the deicing fluids are treated as control parameters. Ignoring the heat exchange between the deicing fluids and the environment, the simplified model is obtained. The rationality of the simplified model is verified by the numerical simulation and the impacts of the flow rate, the initial temperature and the injection time on the deicing process are investigated. To verify the model, the semi-physical experiment system is established, consisting of the low-constant temperature test chamber, the ice simulation system, the deicing fluid heating and spraying system, the simulated wing, the test sensors, and the computer measure and control system. The actual test data verify the validity of the dynamic model and the accuracy of the simulation analysis.

  7. A Study on Simulation of Aircraft Maintenance and Support System

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Maintenance and support are basic elements to realize the effectiveness of aircraft. For basic analysis of the characteristics of an aircraft maintenance and support system, a simulation method is presented in this paper, and the structure and realization ofthe simulation system is discussed.

  8. Numerical simulation and experimental validation of aircraft ground deicing model

    OpenAIRE

    2016-01-01

    Aircraft ground deicing plays an important role of guaranteeing the aircraft safety. In practice, most airports generally use as many deicing fluids as possible to remove the ice, which causes the waste of the deicing fluids and the pollution of the environment. Therefore, the model of aircraft ground deicing should be built to establish the foundation for the subsequent research, such as the optimization of the deicing fluid consumption. In this article, the heat balance of the deicing proce...

  9. A Collection of Nonlinear Aircraft Simulations in MATLAB

    Science.gov (United States)

    Garza, Frederico R.; Morelli, Eugene A.

    2003-01-01

    Nonlinear six degree-of-freedom simulations for a variety of aircraft were created using MATLAB. Data for aircraft geometry, aerodynamic characteristics, mass / inertia properties, and engine characteristics were obtained from open literature publications documenting wind tunnel experiments and flight tests. Each nonlinear simulation was implemented within a common framework in MATLAB, and includes an interface with another commercially-available program to read pilot inputs and produce a three-dimensional (3-D) display of the simulated airplane motion. Aircraft simulations include the General Dynamics F-16 Fighting Falcon, Convair F-106B Delta Dart, Grumman F-14 Tomcat, McDonnell Douglas F-4 Phantom, NASA Langley Free-Flying Aircraft for Sub-scale Experimental Research (FASER), NASA HL-20 Lifting Body, NASA / DARPA X-31 Enhanced Fighter Maneuverability Demonstrator, and the Vought A-7 Corsair II. All nonlinear simulations and 3-D displays run in real time in response to pilot inputs, using contemporary desktop personal computer hardware. The simulations can also be run in batch mode. Each nonlinear simulation includes the full nonlinear dynamics of the bare airframe, with a scaled direct connection from pilot inputs to control surface deflections to provide adequate pilot control. Since all the nonlinear simulations are implemented entirely in MATLAB, user-defined control laws can be added in a straightforward fashion, and the simulations are portable across various computing platforms. Routines for trim, linearization, and numerical integration are included. The general nonlinear simulation framework and the specifics for each particular aircraft are documented.

  10. Aircraft Electronics Maintenance Training Simulator. Curriculum Outlines.

    Science.gov (United States)

    Blackhawk Technical Coll., Janesville, WI.

    Instructional materials are provided for nine courses in an aircraft electronics maintenance training program. Courses are as follows: aviation basic electricity, direct current and alternating current electronics, basic avionic installations, analog electronics, digital electronics, microcomputer electronics, radio communications, aircraft…

  11. 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.

  12. Bioelectric Control of a 757 Class High Fidelity Aircraft Simulation

    Science.gov (United States)

    Jorgensen, Charles; Wheeler, Kevin; Stepniewski, Slawomir; Norvig, Peter (Technical Monitor)

    2000-01-01

    This paper presents results of a recent experiment in fine grain Electromyographic (EMG) signal recognition, We demonstrate bioelectric flight control of 757 class simulation aircraft landing at San Francisco International Airport. The physical instrumentality of a pilot control stick is not used. A pilot closes a fist in empty air and performs control movements which are captured by a dry electrode array on the arm, analyzed and routed through a flight director permitting full pilot outer loop control of the simulation. A Vision Dome immersive display is used to create a VR world for the aircraft body mechanics and flight changes to pilot movements. Inner loop surfaces and differential aircraft thrust is controlled using a hybrid neural network architecture that combines a damage adaptive controller (Jorgensen 1998, Totah 1998) with a propulsion only based control system (Bull & Kaneshige 1997). Thus the 757 aircraft is not only being flown bioelectrically at the pilot level but also demonstrates damage adaptive neural network control permitting adaptation to severe changes in the physical flight characteristics of the aircraft at the inner loop level. To compensate for accident scenarios, the aircraft uses remaining control surface authority and differential thrust from the engines. To the best of our knowledge this is the first time real time bioelectric fine-grained control, differential thrust based control, and neural network damage adaptive control have been integrated into a single flight demonstration. The paper describes the EMG pattern recognition system and the bioelectric pattern recognition methodology.

  13. Digital simulation of V/STOL aircraft for autopilot research

    Science.gov (United States)

    Cicolani, L. S.; Meyer, G.

    1975-01-01

    Simulations of V/STOL aircraft for autopilot research were introduced as examples of large scale systems. A hierarchy of simulations was assembled, and a modular organization was given to the simulations. The dynamics of the system were subdivided into translational and rotational degrees of freedom, based on the different frequencies at which significant variations in motion variables, control forces and moments occur in two subsystems. This is the basis of the autopilot partitioning into two smaller control problems.

  14. Aircraft Simulator Data Requirements Study. Volume II

    Science.gov (United States)

    1977-01-01

    23143 ( Wep ), "Data, Technical Aircraft; for the Design of Aviation Training Devices," was to be used as a guide for the preparation of the new standard. 2...made, displays, etc., utilizing the "hot mockup ." The really useful data can only result from flight tests and can be obtained at any time after tile... mockup " and the preliminary tactical tape used in the tests. It will represent the best system data that will generally be obtained. k The last data

  15. Iced Aircraft Flight Data for Flight Simulator Validation

    Science.gov (United States)

    Ratvasky, Thomas P.; Blankenship, Kurt; Rieke, William; Brinker, David J.

    2003-01-01

    NASA is developing and validating technology to incorporate aircraft icing effects into a flight training device concept demonstrator. Flight simulation models of a DHC-6 Twin Otter were developed from wind tunnel data using a subscale, complete aircraft model with and without simulated ice, and from previously acquired flight data. The validation of the simulation models required additional aircraft response time histories of the airplane configured with simulated ice similar to the subscale model testing. Therefore, a flight test was conducted using the NASA Twin Otter Icing Research Aircraft. Over 500 maneuvers of various types were conducted in this flight test. The validation data consisted of aircraft state parameters, pilot inputs, propulsion, weight, center of gravity, and moments of inertia with the airplane configured with different amounts of simulated ice. Emphasis was made to acquire data at wing stall and tailplane stall since these events are of primary interest to model accurately in the flight training device. Analyses of several datasets are described regarding wing and tailplane stall. Key findings from these analyses are that the simulated wing ice shapes significantly reduced the C , max, while the simulated tail ice caused elevator control force anomalies and tailplane stall when flaps were deflected 30 deg or greater. This effectively reduced the safe operating margins between iced wing and iced tail stall as flap deflection and thrust were increased. This flight test demonstrated that the critical aspects to be modeled in the icing effects flight training device include: iced wing and tail stall speeds, flap and thrust effects, control forces, and control effectiveness.

  16. Ozone-Initiated Chemistry in an Occupied Simulated Aircraft Cabin

    DEFF Research Database (Denmark)

    Weschler, Charles J.; Wisthaler, Armin; Cowlin, Shannon

    2007-01-01

    We have used multiple analytical methods to characterize the gas-phase products formed when ozone was added to cabin air during simulated 4-hour flights that were conducted in a reconstructed section of a B-767 aircraft containing human occupants. Two separate groups of 16 females were each exposed...

  17. 14 CFR 91.1091 - Qualifications: Flight instructors (aircraft) and flight instructors (simulator).

    Science.gov (United States)

    2010-01-01

    ... (aircraft) and flight instructors (simulator). 91.1091 Section 91.1091 Aeronautics and Space FEDERAL... Qualifications: Flight instructors (aircraft) and flight instructors (simulator). (a) For the purposes of this... aircraft, in a flight simulator, or in a flight training device for a particular type, class, or category...

  18. 14 CFR 135.338 - Qualifications: Flight instructors (aircraft) and flight instructors (simulator).

    Science.gov (United States)

    2010-01-01

    ... (aircraft) and flight instructors (simulator). 135.338 Section 135.338 Aeronautics and Space FEDERAL... instructors (aircraft) and flight instructors (simulator). (a) For the purposes of this section and § 135.340... flight simulator, or in a flight training device for a particular type, class, or category aircraft. (2...

  19. Immersive Learning Simulations in Aircraft Maintenance Training

    Science.gov (United States)

    2010-02-15

    You might just get a “serious game,” or “as proposed by the eLearning Guild, you could get an Immersive Learning Simulation.”3 Quoting the... eLearning Guild, Caspian Learning, in a report for the United Kingdom Ministry of Defense, defined an Immersive Learning Simulation (ILS) as “an optimized...their studies that “the savings are more likely to be achieved, and the improvements in training quality more easily justified, when technology is

  20. Initial Study of an Effective Fast-Time Simulation Platform for Unmanned Aircraft System Traffic Management

    Science.gov (United States)

    Xue, Min; Rios, Joseph

    2017-01-01

    Small Unmanned Aerial Vehicles (sUAVs), typically 55 lbs and below, are envisioned to play a major role in surveilling critical assets, collecting important information, and delivering goods. Large scale small UAV operations are expected to happen in low altitude airspace in the near future. Many static and dynamic constraints exist in low altitude airspace because of manned aircraft or helicopter activities, various wind conditions, restricted airspace, terrain and man-made buildings, and conflict-avoidance among sUAVs. High sensitivity and high maneuverability are unique characteristics of sUAVs that bring challenges to effective system evaluations and mandate such a simulation platform different from existing simulations that were built for manned air traffic system and large unmanned fixed aircraft. NASA's Unmanned aircraft system Traffic Management (UTM) research initiative focuses on enabling safe and efficient sUAV operations in the future. In order to help define requirements and policies for a safe and efficient UTM system to accommodate a large amount of sUAV operations, it is necessary to develop a fast-time simulation platform that can effectively evaluate requirements, policies, and concepts in a close-to-reality environment. This work analyzed the impacts of some key factors including aforementioned sUAV's characteristics and demonstrated the importance of these factors in a successful UTM fast-time simulation platform.

  1. A Fixed-Wing Aircraft Simulation Tool for Improving the efficiency of DoD Acquisition

    Science.gov (United States)

    2015-10-05

    05/2015 Oct 2008-Sep 2015 A Fixed- Wing Aircraft Simulation Tool for Improving the Efficiency of DoD Acquisition Scott A. Morton and David R...multi-disciplinary fixed- wing virtual aircraft simulation tool incorporating aerodynamics, structural dynamics, kinematics, and kinetics. Kestrel allows...testing. UU UU UU UU 9 Kevin Newmeyer 703-812-4417 1 A Fixed- Wing Aircraft Simulation Tool for Improving the Efficiency of DoD Acquisition

  2. Simulating the global atmospheric black carbon cycle: a revisit to the contribution of aircraft emissions

    Directory of Open Access Journals (Sweden)

    J. Hendricks

    2004-06-01

    Full Text Available The black carbon (BC burden of the upper troposphere and lowermost stratosphere (UTLS is investigated with the general circulation model (GCM ECHAM4. The special focus is the contribution of aircraft emissions to the UTLS BC loading. Previous studies on the role of aircraft emissions in the global BC cycle either neglect BC sources located at the Earth's surface or simplify the BC cycle by assuming pre-defined BC residence times. Here, the global BC cycle including emissions, transport, and removal is explicitly simulated. The BC emissions considered include surface sources as well as BC from aviation. This enables a consistent calculation of the relative contribution of aviation to the global atmospheric BC cycle. As a further extension to the previous studies, the aviation-induced perturbation of the UTLS BC particle number concentration is investigated. Several sensitivity studies were performed to evaluate the uncertainties associated with the model predictions. The simulated UTLS BC concentrations are compared to in-situ observations. The simulations suggest that the large-scale contribution of aviation to the UTLS BC mass budget typically amounts to only a few percent, even in the most frequented flight regions. The aviation impact far away from these regions is negligible. The simulated aircraft contributions to the UTLS BC particle number concentration are much larger compared to the corresponding mass perturbations. The simulations suggest that aviation can cause large-scale increases in the UTLS BC particle number concentration of more than 30% in regions highly frequented by aircraft. The relative effect shows a pronounced annual variation with the largest relative aviation impact occurring during winter.

  3. Simulating the global atmospheric black carbon cycle: a revisit to the contribution of aircraft emissions

    Directory of Open Access Journals (Sweden)

    J. Hendricks

    2004-01-01

    Full Text Available The black carbon (BC burden of the upper troposphere and lowermost stratosphere (UTLS is investigated with the general circulation model (GCM ECHAM4. The special focus is the contribution of aircraft emissions to the UTLS BC loading. Previous studies on the role of aircraft emissions in the global BC cycle either neglect BC sources located at the Earth's surface or simplify the BC cycle by assuming pre-defined BC residence times. Here, the global BC cycle including emissions, transport, and removal is explicitly simulated. The BC emissions considered include surface sources as well as BC from aviation. This enables a consistent calculation of the relative contribution of aviation to the global atmospheric BC cycle. As a further extension to the previous studies, the aviation-induced perturbation of the UTLS BC particle number concentration is investigated. The uncertainties associated with the model predictions are evaluated by means of several sensitivity studies. Especially, the sensitivity of the results to different assumptions on the BC hygroscopic properties is analysed. The simulated UTLS BC concentrations are compared to in-situ observations. The simulations suggest that the large-scale contribution of aviation to the UTLS BC mass budget typically amounts to only a few percent, even in the most frequented flight regions. The aviation impact far away from these regions is negligible. The simulated aircraft contributions to the UTLS BC particle number concentration are much larger compared to the corresponding mass perturbations. The simulations suggest that aviation can cause large-scale increases in the UTLS BC particle number concentration of more than 30% in regions highly frequented by aircraft. The relative effect shows a pronounced annual variation with the largest relative aviation impact occurring during winter.

  4. The Role of Aircraft Motion in Airborne Gravity Data Quality

    Science.gov (United States)

    Childers, V. A.; Damiani, T.; Weil, C.; Preaux, S. A.

    2015-12-01

    Many factors contribute to the quality of airborne gravity data measured with LaCoste and Romberg-type sensors, such as the Micro-g LaCoste Turnkey Airborne Gravity System used by the National Geodetic Survey's GRAV-D (Gravity for the Redefinition of the American Vertical Datum) Project. For example, it is well documented that turbulence is a big factor in the overall noise level of the measurement. Turbulence is best controlled by avoidance; thus flights in the GRAV-D Project are only undertaken when the predicted wind speeds at flight level are ≤ 40 kts. Tail winds are known to be particularly problematic. The GRAV-D survey operates on a number of aircraft in a variety of wind conditions and geographic locations, and an obvious conclusion from our work to date is that the aircraft itself plays an enormous role in the quality of the airborne gravity measurement. We have identified a number of features of the various aircraft which can be determined to play a role: the autopilot, the size and speed of the aircraft, inherent motion characteristics of the airframe, tip tanks and other modifications to the airframe to reduce motion, to name the most important. This study evaluates the motion of a number of the GRAV-D aircraft and looks at the correlation between this motion and the noise characteristics of the gravity data. The GRAV-D Project spans 7 years and 42 surveys, so we have a significant body of data for this evaluation. Throughout the project, the sensor suite has included an inertial measurement unit (IMU), first the Applanix POSAv, and then later the Honeywell MicroIRS IMU as a part of a NovAtel SPAN GPS/IMU system. We compare the noise characteristics of the data with measures of aircraft motion (via pitch, roll, and yaw captured by the IMU) using a variety of statistical tools. It is expected that this comparison will support the conclusion that certain aircraft tend to work well with this type of gravity sensor while others tend to be problematic in

  5. Dynamic Flight Simulation of aircraft and its comparison to Flight tests

    Directory of Open Access Journals (Sweden)

    Reza Khaki

    2015-09-01

    Full Text Available Nowadays obtaining data for air vehicles researches and analyses is very expensive and risky through the flight tests. Therefore using flight simulation is usually used for the mentioned researches by aerospace science researchers. In this paper, dynamic flight simulation has been performed by airplane nonlinear equations modelling. In these equations, aerodynamic coefficients and stability derivatives have an important role. Therefore, the stability derivatives for typical aircraft are calculated on various flight conditions by analytical and numerical methods. Flight conditions include of Mach number, altitude, angle of attack, control surfaces and CG position variations. The obtained derivatives are used in the form of look up table for dynamic flight simulation and virtual flight. In order to validate the simulation results, the under investigation maneuvres parameters are recorded during many real flights. The obtained data from flight tests are compared with the outputs of flight simulations. The results indicate that less than 13% differences are found in different parts of the maneuvres.

  6. Towards Full Aircraft Airframe Noise Prediction: Lattice Boltzmann Simulations

    Science.gov (United States)

    Khorrami, Mehdi R.; Fares, Ehab; Casalino, Damiano

    2014-01-01

    Computational results for an 18%-scale, semi-span Gulfstream aircraft model are presented. Exa Corporation's lattice Boltzmann PowerFLOW(trademark) solver was used to perform time-dependent simulations of the flow field associated with this high-fidelity aircraft model. The simulations were obtained for free-air at a Mach number of 0.2 with the flap deflected at 39 deg (landing configuration). We focused on accurately predicting the prominent noise sources at the flap tips and main landing gear for the two baseline configurations, namely, landing flap setting without and with gear deployed. Capitalizing on the inherently transient nature of the lattice Boltzmann formulation, the complex time-dependent flow features associated with the flap were resolved very accurately and efficiently. To properly simulate the noise sources over a broad frequency range, the tailored grid was very dense near the flap inboard and outboard tips. Extensive comparison of the computed time-averaged and unsteady surface pressures with wind tunnel measurements showed excellent agreement for the global aerodynamic characteristics and the local flow field at the flap inboard and outboard tips and the main landing gear. In particular, the computed fluctuating surface pressure field for the flap agreed well with the measurements in both amplitude and frequency content, indicating that the prominent airframe noise sources at the tips were captured successfully. Gear-flap interaction effects were remarkably well predicted and were shown to affect only the inboard flap tip, altering the steady and unsteady pressure fields in that region. The simulated farfield noise spectra for both baseline configurations, obtained using a Ffowcs-Williams and Hawkings acoustic analogy approach, were shown to be in close agreement with measured values.

  7. Motion simulation of transport aircraft in extended envelopes : Test pilot assessment

    NARCIS (Netherlands)

    Nooij, S.A.E.; Wentink, M.; Smaili, H.; Zaichik, L.; Groen, E.L.

    2016-01-01

    The European research project SUPRA (“Simulation of Upset Recovery in Aviation”) produced an extended aerodynamic model for simulation of a generic transport aircraft, capturing the key aircraft behavior beyond aerodynamic stall. As described in the current paper, a group of 11 test pilots with

  8. SIMULATION OF WAKE VORTEX AIRCRAFT IN GROUND EFFECT

    Directory of Open Access Journals (Sweden)

    Pamfil ŞOMOIAG

    2011-03-01

    Full Text Available The problem developed in this paper is encountered in airplane aerodynamics and concernsthe influence of long life longitudinal wake vortices generated by wing tips or by external obstaclessuch as reactors or landing gears. More generally it concerns 3D bodies of finite extension in crossflow. At the edge of such obstacles, longitudinal vortices are created by pressure differences inside theboundary layers and rotate in opposite senses. It can constitute a danger to another aircraft that fliesin this wake, especially during takeoff and landing. In this case the wake vortex trajectories andstrengths are altered by ground interactions. This study presents the results of a Large EddySimulation of wake vortex in ground effect providing the vorticity flux behavior.

  9. Simulating the global transport of nitrogen oxides emissions from aircraft

    Science.gov (United States)

    Sausen, R.; Köhler, I.

    1994-05-01

    With the atmosphere general circulation model ECHAM the passive transport of NOx emitted from global subsonic air traffic and the NOx concentration change due to these emissions are investigated. The source of NOx is prescribed according to an aircraft emission data base. The sink of NOx is parameterized as an exponential decay process with globally constant lifetime. Simulations in perpetual January and July modes are performed. Both the resulting mean and the standard deviation of the NOx mass mixing ratio are analysed. In January horizontal dispersion is more pronounced and vertical mixing is smaller than in July. In both cases the resulting quasi-stationary fields of the mass mixing ratio display a pronounced zonal asymmetry. The variability accounts up to 30% of the mean field.

  10. Aircraft

    Science.gov (United States)

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

    1998-01-01

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

  11. Aircraft

    Science.gov (United States)

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

    1998-09-22

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

  12. Aircraft Noise Simulation for a Virtual Reality Environment

    NARCIS (Netherlands)

    Arntzen, M.; Van Veen, T.A.; Visser, H.G.; Simons, D.G.

    2011-01-01

    Aircraft noise annoyance predictions based on traditional tools lack fidelity when modelling a single aircraft flyover. For evaluating annoyance of new procedures, different aircraft types or changing atmospheric conditions, a new modelling approach is necessary. A research effort has been initiated

  13. Improving the Aircraft Design Process Using Web-Based Modeling and Simulation

    Science.gov (United States)

    Reed, John A.; Follen, Gregory J.; Afjeh, Abdollah A.; Follen, Gregory J. (Technical Monitor)

    2000-01-01

    Designing and developing new aircraft systems is time-consuming and expensive. Computational simulation is a promising means for reducing design cycle times, but requires a flexible software environment capable of integrating advanced multidisciplinary and multifidelity analysis methods, dynamically managing data across heterogeneous computing platforms, and distributing computationally complex tasks. Web-based simulation, with its emphasis on collaborative composition of simulation models, distributed heterogeneous execution, and dynamic multimedia documentation, has the potential to meet these requirements. This paper outlines the current aircraft design process, highlighting its problems and complexities, and presents our vision of an aircraft design process using Web-based modeling and simulation.

  14. Numerical simulation of aircraft crash on nuclear containment structure

    Energy Technology Data Exchange (ETDEWEB)

    Iqbal, M.A., E-mail: iqbalfce@iitr.ernet.in [Department of Civil Engineering, Indian Institute of Technology Roorkee, Roorkee 247667 (India); Rai, S.; Sadique, M.R.; Bhargava, P. [Department of Civil Engineering, Indian Institute of Technology Roorkee, Roorkee 247667 (India)

    2012-02-15

    Highlights: Black-Right-Pointing-Pointer The deformation was more localised at the center of cylindrical portion. Black-Right-Pointing-Pointer The peak deflection at the junction of dome and cylinder was found to be 67 mm. Black-Right-Pointing-Pointer The peak deflection at midpoint of the cylindrical portion was found to be 88.9 mm. Black-Right-Pointing-Pointer The strain rate was found to be an important parameter to effect the deformation. Black-Right-Pointing-Pointer The model without strain rate and 290 s{sup -1} strain rate predicted very high deformations. - Abstract: Numerical simulations were carried with ABAQUS/Explicit finite element code in order to predict the response of BWR Mark III type nuclear containment against Boeing 707-320 aircraft crash. The load of the aircraft was applied using and force history curve. The damaged plasticity model was used to predict the behavior of concrete while the Johnson-Cook elasto-viscoplastic material model was used to incorporate the behavior of steel reinforcement. The crash was considered to occur at two different locations i.e., the midpoint of the cylindrical portion and the junction of dome and cylinder. The midpoint of the cylindrical portion experienced more deformation. The strain rate in the material model was varied and found to have a significant effect on the response of containment. The results of the present investigation were compared with those of the studies available in literature and a close agreement with the previous results was found in terms of maximum target deformation.

  15. Flight Dynamics Simulation Modeling and Control of a Large Flexible Tiltrotor Aircraft

    Science.gov (United States)

    2014-09-01

    TECHNICAL REPORT CR-RDMR-AF-14-01 FLIGHT DYNAMICS SIMULATION MODELING AND CONTROL OF A LARGE FLEXIBLE TILTROTOR AIRCRAFT...September 2014 3. REPORT TYPE AND DATES COVERED Final 4. TITLE AND SUBTITLE Flight Dynamics Simulation Modeling and Control of a Large Flexible...18 298-102 i/ii (Blank) FLIGHT DYNAMICS SIMULATION MODELING AND CONTROL OF A LARGE FLEXIBLE TILTROTOR AIRCRAFT by Ondrej Juhasz Dissertation

  16. Aircraft Performance Analysis in Conceptual Design Phase based on System-of-Systems Simulations

    Directory of Open Access Journals (Sweden)

    Tian Yifeng

    2016-01-01

    Full Text Available To obtain a competitive design in aircraft conceptual design phase, this paper propose an aircraft performance analysis method based on system-of-systems (SoS simulations. The analysis process includes design space exploration and mission effectiveness analysis and the stochastic nature in SoS mission is captured based on a Monte Carlo method. Meanwhile as an example, the performance of UAVs which are applied in earthquake search and rescue SoS is analysed based on SoS simulations. The results show that the level of aircraft performance which leads to an optimum SoS effectiveness could be designed below the maximum performance. And it is necessary to apply SoS simulations into aircraft conceptual design phase to help designers optimize aircraft performance.

  17. State estimation approach for live aircraft engagement in a C2 simulation environment

    CSIR Research Space (South Africa)

    Duvenhage, A

    2007-01-01

    Full Text Available react to or engage targets between live and simulated worlds in various ways. State estimation of live aircraft can be a challenge when data from dedicated aircraft transponders is not available. In such cases air picture data have to be used. Often...

  18. Numerical simulation study on air quality in aircraft cabins.

    Science.gov (United States)

    Zhao, Yingjie; Dai, Bingrong; Yu, Qi; Si, Haiqing; Yu, Gang

    2017-06-01

    Air pollution is one of the main factors that affect the air quality in aircraft cabins, and the use of different air supply modes could influence the distribution of air pollutants in cabins. Based on the traditional ceiling air supply mode used on the B737NG, this study investigated another 3 different kinds of air supply modes for comparison: luggage rack air supply mode, joint mode combining ceiling and luggage rack air supply, and joint mode combining ceiling and individual air supply. Under the above 4 air supply modes, the air velocity, temperature and distribution of air pollutants in a cabin full of passengers were studied using computational fluid dynamics (CFD), and carbon dioxide (CO2) and formaldehyde were selected as 2 kinds of representative air pollutants. The simulation results show that the joint mode combining ceiling and individual air supply can create a more uniform distribution of air velocity and temperature, has a better effect on the removal of CO2 and formaldehyde, and can provide better air quality in cabins than the other 3 modes. Copyright © 2016. Published by Elsevier B.V.

  19. Multi-body dynamic system simulation of carrier-based aircraft ski-jump takeoff

    Institute of Scientific and Technical Information of China (English)

    Wang Yangang; Wang Weijun; Qu Xiangju

    2013-01-01

    The flight safety is threatened by the special flight conditions and the low speed of carrier-based aircraft ski-jump takeoff.The aircraft carrier motion,aircraft dynamics,landing gears and wind field of sea state are comprehensively considered to dispose this multidiscipline intersection problem.According to the particular naval operating environment of the carrier-based aircraft ski-jump takeoff,the integrated dynamic simulation models of multi-body system are developed,which involves the movement entities of the carrier,the aircraft and the landing gears,and involves takeoff instruction,control system and the deck wind disturbance.Based on Matlab/Simulink environment,the multi-body system simulation is realized.The validity of the model and the rationality of the result are verified by an example simulation of carrier-based aircraft ski-jump takeoff.The simulation model and the software are suitable for the study of the multidiscipline intersection problems which are involved in the performance,flight quality and safety of carrier-based aircraft takeoff,the effects of landing gear loads,parameters of carrier deck,etc.

  20. ADAPTIVE ASYNCHRONOUS SIMULATED AND METRICAL SOFTWARE PACKAGE IN AIRCRAFT

    Directory of Open Access Journals (Sweden)

    Mr. Vladimir A. Tikhomirov

    2016-09-01

    Full Text Available The article is devoted to the peculiarities and problems of development of applied measuring software packages at the stage of mass production for aircraft avionics testing and measuring.

  1. SIMULATION OF AIRCRAFT CONDENSATION TRAILS AND WAKE VORTICES INTERACTION

    Directory of Open Access Journals (Sweden)

    T. O. Aubakirov

    2015-01-01

    Full Text Available A technique of calculation of aircraft condensation trails (contrails and wake vortices interaction is described. The technique is based on a suitable for real-time applications mathematical model of far wake utilizes the method of discrete vortices. The technique is supplemented by account of the influence of axial velocities in the vortex nucleus on contrail and wake vortex location. Results of calculations of contrails and wake vortices interaction for Il-76 and B-747 aircraft are presented.

  2. Network-based simulation of aircraft at gates in airport terminals

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Y. [ILOG K. K. Japan, Tokyo (Japan)

    1998-03-01

    Simulation is becoming an essential tool for planning, design, and management of airport facilities. A simulation of aircraft at gates at an airport can be applied for various periodically performed applications, relating to the dynamic behavior of aircraft at gates in airport terminals for analyses, evaluations, and decision supports. Conventionally, such simulations are implemented using an event-driven method. For a more efficient simulation, this paper proposes a network-based method. The basic idea is to transform all the sequence constraint relations of aircraft at gates into a network. The simulation is done by calculating the longest path to all the nodes in the network. The effect of the algorithm of the proposed method has been examined by experiments, and the superiority of the proposed method over the event-driven method is revealed through comprehensive comparisons of their overall simulation performance.

  3. Large eddy simulation of soot evolution in an aircraft combustor

    Science.gov (United States)

    Mueller, Michael E.; Pitsch, Heinz

    2013-11-01

    An integrated kinetics-based Large Eddy Simulation (LES) approach for soot evolution in turbulent reacting flows is applied to the simulation of a Pratt & Whitney aircraft gas turbine combustor, and the results are analyzed to provide insights into the complex interactions of the hydrodynamics, mixing, chemistry, and soot. The integrated approach includes detailed models for soot, combustion, and the unresolved interactions between soot, chemistry, and turbulence. The soot model is based on the Hybrid Method of Moments and detailed descriptions of soot aggregates and the various physical and chemical processes governing their evolution. The detailed kinetics of jet fuel oxidation and soot precursor formation is described with the Radiation Flamelet/Progress Variable model, which has been modified to account for the removal of soot precursors from the gas-phase. The unclosed filtered quantities in the soot and combustion models, such as source terms, are closed with a novel presumed subfilter PDF approach that accounts for the high subfilter spatial intermittency of soot. For the combustor simulation, the integrated approach is combined with a Lagrangian parcel method for the liquid spray and state-of-the-art unstructured LES technology for complex geometries. Two overall fuel-to-air ratios are simulated to evaluate the ability of the model to make not only absolute predictions but also quantitative predictions of trends. The Pratt & Whitney combustor is a Rich-Quench-Lean combustor in which combustion first occurs in a fuel-rich primary zone characterized by a large recirculation zone. Dilution air is then added downstream of the recirculation zone, and combustion continues in a fuel-lean secondary zone. The simulations show that large quantities of soot are formed in the fuel-rich recirculation zone, and, furthermore, the overall fuel-to-air ratio dictates both the dominant soot growth process and the location of maximum soot volume fraction. At the higher fuel

  4. The effects of the aircraft cabin environment on passengers during simulated flights

    DEFF Research Database (Denmark)

    Strøm-Tejsen, Peter

    2007-01-01

    A 3-row, 21-seat section of a simulated Boeing 767 aircraft cabin has been built in a climate chamber, simulating the cabin environment not only in terms of materials and geometry, but also in terms of cabin air and wall temperatures and ventilation with very dry air. This realistic simulation...... enables subjective assessments of the symptoms commonly experienced by passengers and crew during flights. Six investigations with subject exposure have subsequently been carried out in the aircraft cabin facility covering four environmental areas of study, i.e. humidity, air purification techniques......, ozone, and thermal effects. The humidity study, examining the optimum balance between fresh air supply and humidity, showed that increasing relative humidity in the aircraft cabin by reducing outside air flow did not reduce the intensity of symptoms typically experienced in the aircraft cabin...

  5. Analyses of Aircraft Responses to Atmospheric Turbulence

    NARCIS (Netherlands)

    Van Staveren, W.H.J.J.

    2003-01-01

    The response of aircraft to stochastic atmospheric turbulence plays an important role in aircraft-design (load calculations), Flight Control System (FCS) design and flight-simulation (handling qualities research and pilot training). In order to simulate these aircraft responses, an accurate

  6. Analyses of Aircraft Responses to Atmospheric Turbulence

    NARCIS (Netherlands)

    Van Staveren, W.H.J.J.

    2003-01-01

    The response of aircraft to stochastic atmospheric turbulence plays an important role in aircraft-design (load calculations), Flight Control System (FCS) design and flight-simulation (handling qualities research and pilot training). In order to simulate these aircraft responses, an accurate mathemat

  7. Factors affecting ozone removal rates in a simulated aircraft cabin environment

    DEFF Research Database (Denmark)

    Tamas, Gyöngyi; Weschler, Charles J.; Bako-Biro, Zsolt

    2006-01-01

    Ozone concentrations were measured concurrently inside a simulated aircraft cabin and in the airstream providing ventilation air to the cabin. Ozone decay rates were also measured after cessation of ozone injection into the supply airstream. By systematically varying the presence or absence...... of people, soiled T-shirts, aircraft seats and a used HEPA filter, we have been able in the course of 24 experiments to isolate the contributions of these and other factors to the removal of ozone from the cabin air. In the case of this simulated aircraft, people were responsible for almost 60% of the ozone...... removal occurring within the cabin and recirculation system; respiration can only have been responsible for about 4% of this removal. The aircraft seats removed about 25% of the ozone; the loaded HEPA filter, 7%; and the other surfaces, 10%. A T-shirt that had been slept in overnight removed roughly 70...

  8. Fault mechanism analysis and simulation for continuity resistance test of electrical components in aircraft engine

    Science.gov (United States)

    Shi, Xudong; Yin, Yaping; Wang, Jialin; Sun, Zhaorong

    2017-01-01

    A large number of electrical components are used in civil aircraft engines, whose electrical circuits are usually intricate and complicated. Continuity resistance is an important parameter for the operating state of electrical components. Electrical continuity fault has serious impact on the reliability of the aircraft engine. In this paper, mathematical models of electrical components are established, and simulation is made by Simulink to analyze the electrical continuity fault.

  9. Computer program to simulate digital computer based longitudinal flight control laws in a high performance aircraft

    OpenAIRE

    Carter, James Robert

    1983-01-01

    Approved for public release; distribution unlimited The IEH Company's Continuous Systems Modeling Program was used to simulate the longitudinal flight control system of the F/A-18 aircraft. The model is intended for use in investigations cf aircraft response to flight conditions which approach spin or stall and is restricted to the automatic flaps up (AFU) flight mode. Program outputs include stabilator deflection, leading and trailing edge flap positions, and cress-ax...

  10. Analyses of Aircraft Responses to Atmospheric Turbulence

    OpenAIRE

    Van Staveren, W.H.J.J.

    2003-01-01

    The response of aircraft to stochastic atmospheric turbulence plays an important role in aircraft-design (load calculations), Flight Control System (FCS) design and flight-simulation (handling qualities research and pilot training). In order to simulate these aircraft responses, an accurate mathematical model is required. Two classical models will be discussed in this thesis, that is the Delft University of Technology (DUT) model and the Four Point Aircraft (FPA) model. Although they are well...

  11. Survivability Modeling & Simulation(Aircraft Survivability, Fall 2009)

    Science.gov (United States)

    2009-01-01

    Mumford Please welcome Carey "Chip" Mumford to the...capabilities and updated penetration equations. COVART Chip Mumford A ir cr af t S ur vi va bi li ty • Fa ll 2 00 9 • h tt ps :/ /j as po .w pa fb...Beach, FL MAY JASP Aircraft Combat Survivability Short Course 4–7 May 2010 NPS, Monterey, CA SpecOps West 2010 10–12 May 2010 Ft. Lewis , WA

  12. WRF simulation of the atmospheric conditions in some aircraft accidents

    OpenAIRE

    Lozano Sánchez, Miguel

    2013-01-01

    Aviation, probably more than any other mode of transportation, is greatly affected by weather. Commercial aviation must deal with storms, fogs, windshears, ash from the volcanoes, intense rain, turbulences and other weather phenomena regularly. In this document are exposed in detail the effects of these phenomena on the aircraft's performance and on the airport facilities. Additionally, it is performed too, a study of the impact that these weather phenomena have had in aviation in the period ...

  13. Modeling and Simulation of Power Distribution System in More Electric Aircraft

    Directory of Open Access Journals (Sweden)

    Zhangang Yang

    2015-01-01

    Full Text Available The More Electric Aircraft concept is a fast-developing trend in modern aircraft industry. With this new concept, the performance of the aircraft can be further optimized and meanwhile the operating and maintenance cost will be decreased effectively. In order to optimize the power system integrity and have the ability to investigate the performance of the overall system in any possible situations, one accurate simulation model of the aircraft power system will be very helpful and necessary. This paper mainly introduces a method to build a simulation model for the power distribution system, which is based on detailed component models. The power distribution system model consists of power generation unit, transformer rectifier unit, DC-DC converter unit, and DC-AC inverter unit. In order to optimize the performance of the power distribution system and improve the quality of the distributed power, a feedback control network is designed based on the characteristics of the power distribution system. The simulation result indicates that this new simulation model is well designed and it works accurately. Moreover, steady state performance and transient state performance of the model can fulfill the requirements of aircraft power distribution system in the realistic application.

  14. Large eddy simulation of air pollution produced by aircraft engine emissions inside the airport

    Energy Technology Data Exchange (ETDEWEB)

    Synylo, Kateryna [National Aviation University (Ukraine)], email: synylo@nau.edu.ua

    2011-07-01

    With the increase of air traffic movement, air pollution from airport emissions has become an important concern. In the past, various research has been undertaken on the impact of aircraft engines on the upper troposphere and lower stratosphere, however the impact that emissions have on airports themselves is not taken into account by the most frequently used monitoring software programs. The aim of this paper is to present the use of a CFD simulation to determine the dynamic and fluid mechanics characteristics of aircraft emissions near the ground. The CFD simulation was carried out using Fluent 6.3 software and the effects of counter-rotating vortices and wind conditions on fulfilled gases jet. It was found that numerical simulation is able to resolve difficult equations and provide realistic results. This study demonstrated that the use of CFD computation could be used to improve local air quality modeling and assessment of the impact of aircraft emissions at airports.

  15. Optimization of a Human-Powered Aircraft Using Fluid–Structure Interaction Simulations

    Directory of Open Access Journals (Sweden)

    Bob Vanderhoydonck

    2016-08-01

    Full Text Available The special type of aircrafts in which the human power of the pilot is sufficient to take off and sustain flight are known as Human-Powered Aircrafts (HPAs. To explore the peculiarities of these aircrafts, the aerodynamic performance of an existing design is evaluated first, using both the vortex lattice method and computational fluid dynamics. In a second step, it is attempted to design and optimize a new HPA capable of winning the Kremer International Marathon Competition. The design will be special in that it allows one to include a second pilot on board the aircraft. As the structural deflection of the wing is found to be a key aspect during design, fluid–structure interaction simulations are performed and included in the optimization procedure. To assess the feasibility of winning the competition, the physical performance of candidate pilots is measured and compared with the predicted required power.

  16. Simulation of Fighter Aircraft Weapon Systems for Design and Performance Evaluation

    OpenAIRE

    P. S. Subramanyam

    1997-01-01

    Simulation forms an essential tool in the system design and performance evaluation of fighter aircraft weapon systems. The various guidance strategies used for weapons like guns, missiles, bombs in the air-to-air or air-to-ground missions, for aiding the pilot for an effective delivery have been studied through extensive off-line and pilot-in-loop simulation. The pilot workload analysis carried out in the high fidelity cockpit simulator at the Aeronautical Development Agency , Bangalor...

  17. Flow simulation and shape optimization for aircraft design

    Science.gov (United States)

    Kroll, Norbert; Gauger, Nicolas R.; Brezillon, Joel; Dwight, Richard; Fazzolari, Antonio; Vollmer, Daniel; Becker, Klaus; Barnewitz, Holger; Schulz, Volker; Hazra, Subhendu

    2007-06-01

    Within the framework of the German aerospace research program, the CFD project MEGADESIGN was initiated. The main goal of the project is the development of efficient numerical methods for shape design and optimization. In order to meet the requirements of industrial implementations a co-operative effort has been set up which involves the German aircraft industry, the DLR, several universities and some small enterprises specialized in numerical optimization. This paper outlines the planned activities within MEGADESIGN, the status at the beginning of the project and it presents some early results achieved in the project.

  18. A method to solve the aircraft magnetic field model basing on geomagnetic environment simulation

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Chunsheng; Zhou, Jian-jun; Yang, Zhen-yu

    2015-06-15

    In aeromagnetic survey, it is difficult to solve the aircraft magnetic field model by flying for some unman controlled or disposable aircrafts. So a model solving method on the ground is proposed. The method simulates the geomagnetic environment where the aircraft is flying and creates the background magnetic field samples which is the same as the magnetic field arose by aircraft’s maneuvering. Then the aircraft magnetic field model can be solved by collecting the magnetic field samples. The method to simulate the magnetic environment and the method to control the errors are presented as well. Finally, an experiment is done for verification. The result shows that the model solving precision and stability by the method is well. The calculated model parameters by the method in one district can be used in worldwide districts as well. - Highlights: • A method to solve the aircraft magnetic field model on the ground is proposed. • The method solves the model by simulating dynamic geomagnetic environment as in the real flying. • The way to control the error of the method was analyzed. • An experiment is done for verification.

  19. A mathematical model for Vertical Attitude Takeoff and Landing (VATOL) aircraft simulation. Volume 2: Model equations and base aircraft data

    Science.gov (United States)

    Fortenbaugh, R. L.

    1980-01-01

    Equations incorporated in a VATOL six degree of freedom off-line digital simulation program and data for the Vought SF-121 VATOL aircraft concept which served as the baseline for the development of this program are presented. The equations and data are intended to facilitate the development of a piloted VATOL simulation. The equation presentation format is to state the equations which define a particular model segment. Listings of constants required to quantify the model segment, input variables required to exercise the model segment, and output variables required by other model segments are included. In several instances a series of input or output variables are followed by a section number in parentheses which identifies the model segment of origination or termination of those variables.

  20. A real-time, dual processor simulation of the rotor system research aircraft

    Science.gov (United States)

    Mackie, D. B.; Alderete, T. S.

    1977-01-01

    A real-time, man-in-the loop, simulation of the rotor system research aircraft (RSRA) was conducted. The unique feature of this simulation was that two digital computers were used in parallel to solve the equations of the RSRA mathematical model. The design, development, and implementation of the simulation are documented. Program validation was discussed, and examples of data recordings are given. This simulation provided an important research tool for the RSRA project in terms of safe and cost-effective design analysis. In addition, valuable knowledge concerning parallel processing and a powerful simulation hardware and software system was gained.

  1. Flight dynamics simulation modeling and control of a large flexible tiltrotor aircraft

    Science.gov (United States)

    Juhasz, Ondrej

    control systems are flown in a fixed-base simulator. Pilot inputs and aircraft performance are recorded and analyzed.

  2. Global contrail coverage simulated by CAM5 with the inventory of 2006 global aircraft emissions

    Directory of Open Access Journals (Sweden)

    Cheryl Craig

    2012-04-01

    Full Text Available This paper documents the incorporation of an inventory of the AEDT (Aviation Environmental Design Tool global commercial aircraft emissions for the year of 2006 into the National Center for Atmospheric Research Community Earth System Model (CESM version 1. The original dataset reports aircraft emission mass of ten specieson an hourly basis which is converted to monthly emission mixing ratio tendencies as the released version of the dataset. We also describe how the released aircraft emission dataset is incorporated into CESM.A contrail parameterization is implemented in the CESM in which it isassumed that persistent contrails initially form when aircraft water vapor emissions experience a favorable atmospheric environment. Both aircraft emissions and ambient humidity are attributed to the formation of contrails. The ice water content of contrails is assumed to follow an empirical function of atmospheric temperature which determines the cloud fraction associated with contrails.Our modeling study indicates that the simulated global contrail coverage is sensitive to the vertical resolution of the GCMsin the upper troposphere and lower stratosphere because of modelassumptions about the vertical overlap structure of clouds.Futhermore, the extent of global contrail coverage simulated by CESM exhibits a seasonal cycle which is in broad agreement with observations.

  3. 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 boun

  4. 14 CFR 91.1089 - Qualifications: Check pilots (aircraft) and check pilots (simulator).

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Qualifications: Check pilots (aircraft) and check pilots (simulator). 91.1089 Section 91.1089 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... RULES Fractional Ownership Operations Program Management § 91.1089 Qualifications: Check...

  5. The influence of ozone on self-evaluation of symptoms in a simulated aircraft cabin

    DEFF Research Database (Denmark)

    Strøm-Tejsen, Peter; Weschler, Charles J.; Wargocki, Pawel

    2008-01-01

    Simulated 4-h flights were carried out in a realistic model of a three-row, 21-seat section of an aircraft cabin that was reconstructed inside a climate chamber. Twenty-nine female subjects, age 19-27 years, were split into two groups; each group was exposed to four conditions: two levels of ozone (...

  6. Products of Ozone-Initiated Chemistry in a Simulated Aircraft Environment

    DEFF Research Database (Denmark)

    Wisthaler, Armin; Tamás, Gyöngyi; Wyon, David P.

    2005-01-01

    We used proton-transfer-reaction mass spectrometry (PTR-MS) to examine the products formed when ozone reacted with the materials in a simulated aircraft cabin, including a loaded high-efficiency particulate air (HEPA) filter in the return air system. Four conditions were examined: cabin (baseline...

  7. Perceived Air Quality of an Occupied, Ozone Exposed, Simulated Aircraft Cabin

    DEFF Research Database (Denmark)

    Tamás, Gyöngyi; Strøm-Tejsen, Peter; Zarzycka, Julita

    2006-01-01

    Perceived air quality was studied in a simulated aircraft cabin. Four different air quality conditions were created at low and high air change rates in the presence and absence of ozone. Two additional assessments of air quality were also performed at high outdoor airflow rates in the absence...

  8. Assessment of the thermal environment in a simulated aircraft cabin using thermal manikin exposure

    DEFF Research Database (Denmark)

    Strøm-Tejsen, Peter; Zukowska, Daria; Jama, Agnieszka

    2007-01-01

    The thermal environment in a full-scale 21-seat section of an aircraft cabin installed in a climate chamber was investigated. Fourteen heated cylinders and two thermal manikins were used to simulate the heat load, buoyancy flow and flow obstruction from passengers in the cabin. Measurements were...

  9. Finger temperature as a predictor of thermal comfort for sedentary passengers in a simulated aircraft cabin

    DEFF Research Database (Denmark)

    Strøm-Tejsen, Peter; Wyon, David Peter; Zukowska, Daria

    2009-01-01

    Experiments were carried out in a simulated aircraft cabin with 21 seats installed in a climate chamber, to determine the extent to which passengers’ perception of cabin air quality is affected by air temperature. The temperature inside the cabin was set at three different levels, 20.6, 23.3 and 26...

  10. 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

  11. Perceived Air Quality of an Occupied, Ozone Exposed, Simulated Aircraft Cabin

    DEFF Research Database (Denmark)

    Tamás, Gyöngyi; Strøm-Tejsen, Peter; Zarzycka, Julita

    2006-01-01

    Perceived air quality was studied in a simulated aircraft cabin. Four different air quality conditions were created at low and high air change rates in the presence and absence of ozone. Two additional assessments of air quality were also performed at high outdoor airflow rates in the absence...

  12. TransCom model simulations of methane: Comparison of vertical profiles with aircraft measurements

    NARCIS (Netherlands)

    Saito, R.; Patra, P.K.; Sweeney, C.; Machida, T.; Krol, M.C.; Houweling, S.; Bousquet, P.; Agusti-Panareda, A.; Belikov, D.; Bergmann, D.; Bian, H.S.; Cameron-Smith, P.; Chipperfield, M.P.; Fortems-Cheiney, A.; Fraser, A.; Gatti, L.V.; Gloor, E.; Hess, P.; Kawa, S.R.; Law, R.M.; Locatelli, R.; Loh, Z.; Maksyutov, S.; Meng, L.; Miller, J.B.; Palmer, P.I.; Prinn, R.G.; Rigby, M.; Wilson, C.

    2013-01-01

    To assess horizontal and vertical transports of methane (CH4) concentrations at different heights within the troposphere, we analyzed simulations by 12 chemistry transport models (CTMs) that participated in the TransCom-CH4 intercomparison experiment. Model results are compared with aircraft measure

  13. Simulation of Fighter Aircraft Weapon Systems for Design and Performance Evaluation

    Directory of Open Access Journals (Sweden)

    P.S. Subramanyam

    1997-07-01

    Full Text Available Simulation forms an essential tool in the system design and performance evaluation of fighter aircraft weapon systems. The various guidance strategies used for weapons like guns, missiles, bombs in the air-to-air or air-to-ground missions, for aiding the pilot for an effective delivery have been studied through extensive off-line and pilot-in-loop simulation. The pilot workload analysis carried out in the high fidelity cockpit simulator at the Aeronautical Development Agency , Bangalore, provides the system designer an effective means to tune the various subsy stems for better performance. The paper focuses on all these aspects to bring out the importance of simulation in the overall fighter aircraft weapon system design.

  14. A Comparison of Force-Time History Analysis Methods for Simplified Aircraft Impact Simulation

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Sangshup; Hahm, Daegi; Choi, In Kil [Korea Atomic Energy Research institute, Daejeon (Korea, Republic of)

    2013-10-15

    In this paper, by comparing the various F-T History analysis method, we are about to propose the most reliable simplified method under the same condition with M-T Interaction analysis method. To find the suitable loading area applied aircraft crash, the studies for a various loading area (Case 1, 2, 3) ware performed using F-T History analysis method, and the former results were compared to the result of Case 4 using M-T Interaction analysis method. The various results according to the proposed loading area were pointed out. Thus, the results for a simplified loading area applied impact load may be fairly sensitive to the assumption associated with loading area. Finally, we can conclude that the Case 3 shows conservative and the most similar results with realistic simulation using M-T Interaction analysis method, i. e., Case 4. The reaction force-time relationship for accidental strike of Boeing 707-320 aircraft against a rigid surface was proposed by Riera. After that, the aircraft impact analysis has been studied significantly in the last few decades. The only way to acquire an exact solution of the aircraft impact analysis is direct impact test. However, for the large commercial aircraft impact, this direct test has been hardly performed because the scale of aircraft and impacted wall is very huge. Up to date, the numerical simulation using Missile-Target (M-T) Interaction analysis method is known as the only way to obtain a relatively accurate solution. However, because of its massive computational efforts and modeling complexity, this method is inadequate and inefficient to the application of the fragility analysis and risk assessments which is required many times of iterative simulations. Thus, a more simplified and conservative analysis method is required. The simplified method such as Force-Time (F-T) History analysis method has been studied by Riera, Sugano et al., Mullapudi et al. and etc.

  15. TransCom model simulations of methane: Comparison of vertical profiles with aircraft measurements

    OpenAIRE

    Saito, R.; Patra, PK; C. Sweeney; Machida, T.; Krol, M.; Houweling, S.; Bousquet, P.; Agusti-Panareda, A.; D. Belikov; D. Bergmann; H. Bian; P. Cameron-Smith; Chipperfield, MP; Fortems-Cheiney, A.; Fraser, A.

    2013-01-01

    To assess horizontal and vertical transports of methane (CH4) concentrations at different heights within the troposphere, we analyzed simulations by 12 chemistry transport models (CTMs) that participated in the TransCom-CH4 intercomparison experiment. Model results are compared with aircraft measurements at 13 sites in Amazon/Brazil, Mongolia, Pacific Ocean, Siberia/Russia, and United States during the period of 2001-2007. The simulations generally show good agreement with observations for se...

  16. Relating a Jet-Surface Interaction Experiment to a Commercial Supersonic Transport Aircraft Using Numerical Simulations

    Science.gov (United States)

    Dippold, Vance F. III; Friedlander, David

    2017-01-01

    Reynolds-Averaged Navier-Stokes (RANS) simulations were performed for a commercial supersonic transport aircraft concept and experimental hardware models designed to represent the installed propulsion system of the conceptual aircraft in an upcoming test campaign. The purpose of the experiment is to determine the effects of jet-surface interactions from supersonic aircraft on airport community noise. RANS simulations of the commercial supersonic transport aircraft concept were performed to relate the representative experimental hardware to the actual aircraft. RANS screening simulations were performed on the proposed test hardware to verify that it would be free from potential rig noise and to predict the aerodynamic forces on the model hardware to assist with structural design. The simulations showed a large region of separated flow formed in a junction region of one of the experimental configurations. This was dissimilar with simulations of the aircraft and could invalidate the noise measurements. This configuration was modified and a subsequent RANS simulation showed that the size of the flow separation was greatly reduced. The aerodynamic forces found on the experimental models were found to be relatively small when compared to the expected loads from the model’s own weight.Reynolds-Averaged Navier-Stokes (RANS) simulations were completed for two configurations of a three-stream inverted velocity profile (IVP) nozzle and a baseline single-stream round nozzle (mixed-flow equivalent conditions). For the Sideline and Cutback flow conditions, while the IVP nozzles did not reduce the peak turbulent kinetic energy on the lower side of the jet plume, the IVP nozzles did significantly reduce the size of the region of peak turbulent kinetic energy when compared to the jet plume of the baseline nozzle cases. The IVP nozzle at Sideline conditions did suffer a region of separated flow from the inner stream nozzle splitter that did produce an intense, but small, region of

  17. Occupant evaluation of 7-hour exposures in a simulated aircraft cabin - Part 2: Thermal effects

    DEFF Research Database (Denmark)

    Strøm-Tejsen, Peter; Wyon, David Peter; Zukowska, Daria

    2005-01-01

    Experiments were carried out in a simulated section of an aircraft cabin with 21 seats installed in a climate chamber, to determine the extent to which passengers’ perception of cabin air quality is affected by air temperature. The temperature inside the cabin was set at three differ-ent levels, 20...... of air quality, cabin environment, intensity of symptoms commonly experienced during flight, and thermal comfort. The investigation showed that cabin air temperature did not change symptoms typical of the aircraft cabin environment whereas it did significantly affect air quality, freshness of air...

  18. Occupant evaluation of 7-hour exposures in a simulated aircraft cabin - Part 2: Thermal effects

    DEFF Research Database (Denmark)

    Strøm-Tejsen, Peter; Wyon, David Peter; Zukowska, Daria;

    2005-01-01

    Experiments were carried out in a simulated section of an aircraft cabin with 21 seats installed in a climate chamber, to determine the extent to which passengers’ perception of cabin air quality is affected by air temperature. The temperature inside the cabin was set at three differ-ent levels, 20...... of air quality, cabin environment, intensity of symptoms commonly experienced during flight, and thermal comfort. The investigation showed that cabin air temperature did not change symptoms typical of the aircraft cabin environment whereas it did significantly affect air quality, freshness of air...

  19. Theoretical modeling and computational simulation of robust control for Mars aircraft

    Science.gov (United States)

    Oh, Seyool

    The focus of this dissertation is the development of control system design algorithms for autonomous operation of an aircraft in the Martian atmosphere. This research will show theoretical modeling and computational simulation of robust control and gain scheduling for a prototype Mars aircraft. A few hundred meters above the surface of Mars, the air density is less than 1% of the density of the Earth's atmosphere at sea level. However, at about 33 km (110,000 ft) above the Earth, the air density is similar to that near the surface of Mars. Marsflyer II was designed to investigate these flight regimes: 33 km above the Earth and the actual Mars environment. The fuselage for the preliminary design was cylindrical with a length of 2.59 m (8.49 ft), the wing span was 3.98 m (13.09 ft). The total weight of the demonstrator aircraft was around 4.54 kg (10.02 lb). Aircraft design tools have been developed based on successful aircraft for the Earth`s atmosphere. However, above Mars an airborne robotic explorer would encounter low Reynolds Number flow phenomena combined with high Mach numbers, a region that is unknown for normal Earth aerodynamic applications. These flows are more complex than those occurring at high Reynolds numbers. The performance of airfoils at low Reynolds numbers is poorly understood and generally results in unfavorable aerodynamic characteristics. Design and simulation tools for the low Reynolds number Martian environment could be used to develop Unmanned Aerial Vehicles (UAV). In this study, a robust control method is used to analyze a prototype Mars aircraft. The purpose of this aircraft is to demonstrate stability, control, and performance within a simulated Mars environment. Due to uncertainty regarding the actual Martian environment, flexibility in the operation of the aircraft`s control system is important for successful performance. The stability and control derivatives of Marsflyer II were obtained by using the Advanced Aircraft Analysis (AAA

  20. Verification of the CFD simulation system SAUNA for complex aircraft configurations

    Science.gov (United States)

    Shaw, Jonathon A.; Peace, Andrew J.; May, Nicholas E.; Pocock, Mark F.

    1994-04-01

    This paper is concerned with the verification for complex aircraft configurations of an advanced CFD simulation system known by the acronym SAUNA. A brief description of the complete system is given, including its unique use of differing grid generation strategies (structured, unstructured or both) depending on the geometric complexity of the addressed configuration. The majority of the paper focuses on the application of SAUNA to a variety of configurations from the military aircraft, civil aircraft and missile areas. Mesh generation issues are discussed for each geometry and experimental data are used to assess the accuracy of the inviscid (Euler) model used. It is shown that flexibility and accuracy are combined in an efficient manner, thus demonstrating the value of SAUNA in aerodynamic design.

  1. GL Studio Brings Realism to Aircraft Cockpit Simulator Displays

    Science.gov (United States)

    2007-06-01

    becoming unsup- portable. A unique CIF simulation execut- ed on a single - board computer (SBC) for each of the seven systems. The SBC code communicated...Implemented Configuration Shared Memory CIF Client Server GUI Server Client Single Board Computer Linux PC (Silicon Graphics Replacement) RPC RPC Quadro FX

  2. Using Intelligent Simulation to Enhance Human Performance in Aircraft Maintenance

    Science.gov (United States)

    Johnson, William B.; Norton, Jeffrey E.

    1992-01-01

    Human factors research and development investigates the capabilities and limitations of the human within a system. Of the many variables affecting human performance in the aviation maintenance system, training is among the most important. The advent of advanced technology hardware and software has created intelligent training simulations. This paper describes one advanced technology training system under development for the Federal Aviation Administration.

  3. Simulated transonic flows for aircraft with nacelles, pylons, and winglets

    Science.gov (United States)

    Boppe, C. W.; Stern, M. A.

    1980-01-01

    A computational method which simulates transonic flow about wing-fuselage configurations has been extended to include the treatment of multiple body and non-planar wing surfaces. The finite difference relaxation scheme is characterized by a modified small disturbance flow equation and multiple embedded grid system. Wing-body combinations with as many as four nacelles/pods, four pylons, and wing-tip-mounted winglets can be analyzed. A scheme for modeling inlet spillage and engine exhaust interference effects has been included. Computed results are correlated with experimental data for three transport configurations.

  4. The FEM simulation of the thin walled aircraft engine corpus deformation during milling

    Science.gov (United States)

    Matras, A.; Plaza, M.

    2016-09-01

    This paper discusses the results of the experimental research performed with the support of finite element method. The deformation of the thin walled aircraft engine corpus was analyzed based on a geometric model. Then, the boundary of the outer side of the part was loaded by the components of a cutting force during milling. The material model of the part was also defined in the simulation software. The analysis allowed to optimize feed rate in order to decrease the deformation of the part.

  5. Simulation of lightning attachment to open ground, tall towers and aircraft

    Energy Technology Data Exchange (ETDEWEB)

    Ratnamahilan, P.; Hoole, P. (Univ. of Technology, Lae (Papua New Guinea). Dept. of Electrical and Telecommunications Engineering); Ratnajeevan, S.; Hoole, H. (Harvey Mudd College, Claremont, CA (United States). Dept. of Engineering)

    1993-04-01

    The characteristics of lightning waveforms are important in taking protective measures against it. However, many of these characteristics cannot be measured. This paper employs a mathematical model of lightning currents to write a software package to simulate all manner of lightning flashes. The capabilities available to us through this are demonstrated by extracting the behavior of lightning waveforms following attachment to open ground, tall towers and aircraft.

  6. Current Methods for Modeling and Simulating Icing Effects on Aircraft Performance, Stability and Control

    Science.gov (United States)

    Ralvasky, Thomas P.; Barnhart, Billy P.; Lee, Sam

    2008-01-01

    Icing alters the shape and surface characteristics of aircraft components, which results in altered aerodynamic forces and moments caused by air flow over those iced components. The typical effects of icing are increased drag, reduced stall angle of attack, and reduced maximum lift. In addition to the performance changes, icing can also affect control surface effectiveness, hinge moments, and damping. These effects result in altered aircraft stability and control and flying qualities. Over the past 80 years, methods have been developed to understand how icing affects performance, stability and control. Emphasis has been on wind tunnel testing of two-dimensional subscale airfoils with various ice shapes to understand their effect on the flow field and ultimately the aerodynamics. This research has led to wind tunnel testing of subscale complete aircraft models to identify the integrated effects of icing on the aircraft system in terms of performance, stability, and control. Data sets of this nature enable pilot in the loop simulations to be performed for pilot training, or engineering evaluation of system failure impacts or control system design.

  7. Current Methods Modeling and Simulating Icing Effects on Aircraft Performance, Stability, Control

    Science.gov (United States)

    Ratvasky, Thomas P.; Barnhart, Billy P.; Lee, Sam

    2010-01-01

    Icing alters the shape and surface characteristics of aircraft components, which results in altered aerodynamic forces and moments caused by air flow over those iced components. The typical effects of icing are increased drag, reduced stall angle of attack, and reduced maximum lift. In addition to the performance changes, icing can also affect control surface effectiveness, hinge moments, and damping. These effects result in altered aircraft stability and control and flying qualities. Over the past 80 years, methods have been developed to understand how icing affects performance, stability, and control. Emphasis has been on wind-tunnel testing of two-dimensional subscale airfoils with various ice shapes to understand their effect on the flowfield and ultimately the aerodynamics. This research has led to wind-tunnel testing of subscale complete aircraft models to identify the integrated effects of icing on the aircraft system in terms of performance, stability, and control. Data sets of this nature enable pilot-in-the-loop simulations to be performed for pilot training or engineering evaluation of system failure impacts or control system design.

  8. Evaluation of simulation-based training for aircraft carrier marshalling with learning cubic and Kirkpatrick’s models

    Institute of Scientific and Technical Information of China (English)

    Tian Yongliang; Liu Hu; Yin Jiao; Luo Mingqiang; Wu Guanghui

    2015-01-01

    Simulation-based training is a promising way to train a carrier flight deck crew because of the complex and dangerous working environment. Quantitative evaluation of simulation-based training quality is vital to make simulation-based training practical for aircraft carrier marshalling. This paper develops a personal computer-based aircraft carrier marshalling simulation system and a cave automatic virtual environment (CAVE)-based immersive environment. In order to compare the training effectiveness of simulation-based training and paper-based training, a learning cubic model is proposed and a contrast experiment is carried out as well. The experimental data is ana-lyzed based on a simplified Kirkpatrick’s model. The results show that simulation-based training is better than paper-based training by 26.80%after three rounds of testing, which prove the effective-ness of simulation-based aircraft carrier marshalling training.

  9. Unmanned Carrier-Based Aircraft System: Debate over Systems Role Led to Focus on Aerial Refueling

    Science.gov (United States)

    2016-03-24

    Unmanned Carrier-Based Aircraft System: Debate over System’s Role Led to Focus on Aerial Refueling Prior to February 2016, the Navy had planned to...pages in the publication and whether the publication is printed in color or black and white . Pricing and ordering information is posted on GAO’s

  10. Assessment of the thermal environment in a simulated aircraft cabin using thermal manikin exposure

    DEFF Research Database (Denmark)

    Strøm-Tejsen, Peter; Zukowska, Daria; Jama, Agnieszka

    2007-01-01

    investigation in which 4 groups of 17 subjects participated, each group being exposed to the same three temperature conditions during simulated 7-hour transatlantic flights. The assessments indicate that an air temperature increase in the middle of a 7-hour flight period followed by a decrease before landing......The thermal environment in a full-scale 21-seat section of an aircraft cabin installed in a climate chamber was investigated. Fourteen heated cylinders and two thermal manikins were used to simulate the heat load, buoyancy flow and flow obstruction from passengers in the cabin. Measurements were...

  11. Aircraft-based observations and high-resolution simulations of an Icelandic dust storm

    Directory of Open Access Journals (Sweden)

    A.-M. Blechschmidt

    2012-11-01

    Full Text Available The first aircraft-based observations of an Icelandic dust storm are presented. The measurements were carried out over the ocean near Iceland's south coast in February 2007. This dust event occurred in conjunction with an easterly barrier jet of more than 30 m s−1. The aircraft measurements show high particle mass mixing ratios in an area of low wind speeds in the wake of Iceland near the coast, decreasing abruptly towards the jet. Simulations from the Weather Research and Forecasting Model coupled with Chemistry (WRF/Chem indicate that the measured high mass mixing ratios and observed low visibility inside the wake are due to dust transported from Icelandic sand fields towards the ocean. This is confirmed by meteorological station data. Glacial outwash terrains located near the Mýrdalsjökull glacier are among simulated dust sources. Sea salt aerosols produced by the impact of strong winds on the ocean surface started to dominate as the aircraft flew away from Iceland into the jet. The present results support recent studies which suggest that Icelandic deserts should be considered as important dust sources in global and regional climate models.

  12. Simulator Evaluation of Simplified Propulsion-Only Emergency Flight Control Systems on Transport Aircraft

    Science.gov (United States)

    Burcham, Frank W., Jr.; Kaneshige, John; Bull, John; Maine, Trindel A.

    1999-01-01

    With the advent of digital engine control systems, considering the use of engine thrust for emergency flight control has become feasible. Many incidents have occurred in which engine thrust supplemented or replaced normal aircraft flight controls. In most of these cases, a crash has resulted, and more than 1100 lives have been lost. The NASA Dryden Flight Research Center has developed a propulsion-controlled aircraft (PCA) system in which computer-controlled engine thrust provides emergency flight control capability. Using this PCA system, an F-15 and an MD-11 airplane have been landed without using any flight controls. In simulations, C-17, B-757, and B-747 PCA systems have also been evaluated successfully. These tests used full-authority digital electronic control systems on the engines. Developing simpler PCA systems that can operate without full-authority engine control, thus allowing PCA technology to be installed on less capable airplanes or at lower cost, is also a desire. Studies have examined simplified ?PCA Ultralite? concepts in which thrust control is provided using an autothrottle system supplemented by manual differential throttle control. Some of these concepts have worked well. The PCA Ultralite study results are presented for simulation tests of MD-11, B-757, C-17, and B-747 aircraft.

  13. Delayed detached eddy simulations of fighter aircraft at high angle of attack

    Institute of Scientific and Technical Information of China (English)

    Guoliang Xu; Xiong Jiang; Gang Liu

    2016-01-01

    The massively separated flows over a realistic air-craft configuration at 40◦, 50◦, and 60◦angles of attack are studied using the delayed detached eddy simulation (DDES). The calculations are carried out at experimental conditions corresponding to a mean aerodynamic chord-based Reynolds number of 8.93 × 105 and Mach number of 0.088. The influ-ence of the grid size is investigated using two grids, 20.0×106 cells and 31.0 × 106 cells. At the selected conditions, the lift, drag, and pitching moment from DDES predictions agree with the experimental data better than that from the Reynolds-averaged Navier–Stokes. The effect of angle of attack on the flow structure over the general aircraft is also studied, and it is found that the dominated frequency associated with the vortex shedding process decreases with increasing angle of attack.

  14. Detection and sizing of short fatigue cracks in a simulated aircraft structure of aluminum thin plate

    Energy Technology Data Exchange (ETDEWEB)

    KIm, Jung Chan; Kwon, Oh Yang [Inha University, Incheon (Korea, Republic of)

    2004-05-15

    Since the fatigue damage usually occurs around the rivet holes in aircraft structures, the detection and sizing of short fatigue cracks emanating from rivet holes is extremely important. The initiation of fatigue cracks in a simulated aircraft structures with a series of rivet holes was detected by acoustic emission(AE), and the crack length was determined by the surface acoustic wave(SAW) technique. AE events increased intermittently with the initiation and growth of short cracks to form a stepwise incremental curve of cumulative AE events. with the SAW technique employed, the crack sizing in the range of 1-8 mm long was possible but it was impossible in the range shorter than 1 mm.

  15. The effect of aircraft control forces on pilot performance during instrument landings in a flight simulator.

    Science.gov (United States)

    Hewson, D J; McNair, P J; Marshall, R N

    2001-07-01

    Pilots may have difficulty controlling aircraft at both high and low force levels due to larger variability in force production at these force levels. The aim of this study was to measure the force variability and landing performance of pilots during an instrument landing in a flight simulator. There were 12 pilots who were tested while performing 5 instrument landings in a flight simulator, each of which required different control force inputs. Pilots can produce the least force when pushing the control column to the right, therefore the force levels for the landings were set relative to each pilot's maximum aileron-right force. The force levels for the landings were 90%, 60%, and 30% of maximal aileron-right force, normal force, and 25% of normal force. Variables recorded included electromyographic activity (EMG), aircraft control forces, aircraft attitude, perceived exertion and deviation from glide slope and heading. Multivariate analysis of variance was used to test for differences between landings. Pilots were least accurate in landing performance during the landing at 90% of maximal force (p < 0.05). There was also a trend toward decreased landing performance during the landing at 25% of normal force. Pilots were more variable in force production during the landings at 60% and 90% of maximal force (p < 0.05). Pilots are less accurate at performing instrument landings when control forces are high due to the increased variability of force production. The increase in variability at high force levels is most likely associated with motor unit recruitment, rather than rate coding. Aircraft designers need to consider the reduction in pilot performance at high force levels, as well as pilot strength limits when specifying new standards.

  16. Simulating the Impact Response of Three Full-Scale Crash Tests of Cessna 172 Aircraft

    Science.gov (United States)

    Jackson, Karen E.; Fasanella, Edwin L.; Littell, Justin D.; Annett, Martin S.; Stimson, Chad M.

    2017-01-01

    During the summer of 2015, a series of three full-scale crash tests were performed at the Landing and Impact Research Facility located at NASA Langley Research Center of Cessna 172 aircraft. The first test (Test 1) represented a flare-to-stall emergency or hard landing onto a rigid surface. The second test (Test 2) represented a controlled-flight- into-terrain (CFIT) with a nose down pitch attitude of the aircraft, which impacted onto soft soil. The third test (Test 3) also represented a CFIT with a nose up pitch attitude of the aircraft, which resulted in a tail strike condition. Test 3 was also conducted onto soft soil. These crash tests were performed for the purpose of evaluating the performance of Emergency Locator Transmitters and to generate impact test data for model calibration. Finite element models were generated and impact analyses were conducted to simulate the three impact conditions using the commercial nonlinear, transient dynamic finite element code, LS-DYNA®. The objective of this paper is to summarize test-analysis results for the three full-scale crash tests.

  17. Lamb wave characterization of corrosion-thinning in aircraft stringers: experiment and three-dimensional simulation.

    Science.gov (United States)

    Bingham, Jill; Hinders, Mark

    2009-07-01

    The development of automatic guided wave interpretation for detecting corrosion in aluminum aircraft structural stringers is described. The dynamic wavelet fingerprint technique (DWFT) is used to render the guided wave mode information in two-dimensional binary images. Automatic algorithms then extract DWFT features that correspond to the distorted arrival times of the guided wave modes of interest, which give insight into changes of the structure in the propagation path. To better understand how the guided wave modes propagate through real structures, parallel-processing elastic wave simulations using the finite integration technique (EFIT) has been performed. Three-dimensional (3D) simulations are used to examine models too complex for analytical solutions. They produce informative visualizations of the guided wave modes in the structures and mimic the output from sensors placed in the simulation space. Using the previously developed mode extraction algorithms, the 3D EFIT results are compared directly to their experimental counterparts.

  18. Finger temperature as a predictor of thermal comfort for sedentary passengers in a simulated aircraft cabin

    DEFF Research Database (Denmark)

    Strøm-Tejsen, Peter; Wyon, David Peter; Zukowska, Daria

    2009-01-01

    Experiments were carried out in a simulated aircraft cabin with 21 seats installed in a climate chamber, to determine the extent to which passengers’ perception of cabin air quality is affected by air temperature. The temperature inside the cabin was set at three different levels, 20.6, 23.3 and 26.......1°C. A total of 68 subjects were exposed to each of the three conditions. The subjects completed questionnaires to provide subjective assessments of air quality, cabin environment, intensity of symptoms commonly experienced during flight, and thermal comfort. Objective physiological measurements...

  19. Multi-agent Based Hierarchy Simulation Models of Carrier-based Aircraft Catapult Launch

    Institute of Scientific and Technical Information of China (English)

    Wang Weijun; Qu Xiangju; Guo Linliang

    2008-01-01

    With the aid of multi-agent based modeling approach to complex systems,the hierarchy simulation models of carrier-based aircraft catapult launch are developed.Ocean,carrier,aircraft,and atmosphere are treated as aggregation agents,the detailed components like catapult,landing gears,and disturbances are considered as meta-agents,which belong to their aggregation agent.Thus,the model with two layers is formed i.e.the aggregation agent layer and the meta-agent layer.The information communication among all agents is described.The meta-agents within one aggregation agent communicate with each other directly by information sharing,but the meta-agents,which belong to different aggregation agents exchange their information through the aggregation layer fast,and then perceive it from the sharing environment,that is the aggregation agent.Thus,not only the hierarchy model is built,but also the environment perceived by each agent is specified.Meanwhile,the problem of balancing the independency of agent and the resource consumption brought by real-time communication within multi-agent system (MAS) is resolved.Each agent involved in carrier-based aircraft catapult launch is depicted,with considering the interaction within disturbed atmospheric environment and multiple motion bodies including carrier,aircraft,and landing gears.The models of reactive agents among them are derived based on tensors,and the perceived messages and inner frameworks of each agent are characterized.Finally,some results of a simulation instance are given.The simulation and modeling of dynamic system based on multi-agent system is of benefit to express physical concepts and logical hierarchy clearly and precisely.The system model can easily draw in kinds of other agents to achieve a precise simulation of more complex system.This modeling technique makes the complex integral dynamic equations of multibodies decompose into parallel operations of single agent,and it is convenient to expand,maintain,and reuse

  20. Trends in aircraft emissions. Simulation of two air traffic scenarios in Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Larson, L.G.; Palsson, A. [The Aeronautical Research Inst. of Sweden, Bromma (Sweden). The Swedish Civil Aviation Administration

    1997-12-31

    The developing trends of emissions from aviation in Sweden have been studied by means of flight and emissions simulation. The objective was to investigate whether technical improvements will allow Swedish air traffic to increase, without exceeding national regulations for pollution in the future. It was found that, due to development of aircraft engines and, to some extent, improvement of aerodynamic designs, the fuel consumption and thus the emissions of carbon dioxide will decrease in the future. The decrease of nitrous oxides is predicted to be significant due to advances in engine technology. (author) 4 refs.

  1. Real-time Simulation of Large Aircraft Flying Through Microburst Wind Field

    Institute of Scientific and Technical Information of China (English)

    Gao Zhenxing; Gu Hongbin; Liu Hui

    2009-01-01

    This article deals with real-time hi-fi simulation of large aircraft flying in turbulent wind in a simulator to study its takeoff and landing behavior in microburst wind shear. A parameterized three-dimensional (3D) microburst model is built up on the basis of vortex ring and Rankine vortex principle. Complicated microburst wind fields are simulated by means of vortex ring declination and multi-vortex superposition. Based on the modeling data of Boeing 747-100, a dynamic model with wind shear effects considered is established and a general method to modify the aerodynamic model is proposed. A controller for longitudinal and lateral escapes is designed and verified in simulated microburst wind field. Results indicate that, with high extensibility, reasonability and effectiveness, the 3D microburst model with wind shear effects considered is fit to simulate real wind fields. Different escape schemes can be adopted to fly through a wind field from different locations. The model can be used for real-time flight simulation in a flight simulator.

  2. Numerical simulation of aerodynamic interaction for a tilt rotor aircraft in helicopter mode

    Institute of Scientific and Technical Information of China (English)

    Ye Liang; Zhang Ying; Yang Shuo; Zhu Xinglin; Dong Jun

    2016-01-01

    A rotor CFD solver is developed for simulating the aerodynamic interaction phe-nomenon among rotor, wing and fuselage of a tilt rotor aircraft in its helicopter mode. The unsteady Navier–Stokes equations are discretized in inertial frame and embedded grid system is adopted for describing the relative motion among blades and nacelle/wing/fuselage. A combination of multi-layer embedded grid and‘‘extended hole fringe”technique is complemented in original grid system to tackle grid assembly difficulties arising from the narrow space among different aerody-namic components, and to improve the interpolation precision by decreasing the cell volume dis-crepancy among different grid blocks. An overall donor cell searching and automatic hole cutting technique is used for grid assembly, and the solution processes are speeded up by introduc-tion of OpenMP parallel method. Based on this solver, flow fields and aerodynamics of a tilt rotor aircraft in hover are simulated with several rotor collective angles, and the corresponding states of an isolated rotor and rotor/wing/fuselage model are also computed to obtain reference solution. Aerodynamic interference influences among the rotor and wing/fuselage/nacelle are analyzed, and some meaningful conclusions are drawn.

  3. Simulation Modeling Requirements for Loss-of-Control Accident Prevention of Turboprop Transport Aircraft

    Science.gov (United States)

    Crider, Dennis; Foster, John V.

    2012-01-01

    In-flight loss of control remains the leading contributor to aviation accident fatalities, with stall upsets being the leading causal factor. The February 12, 2009. Colgan Air, Inc., Continental Express flight 3407 accident outside Buffalo, New York, brought this issue to the forefront of public consciousness and resulted in recommendations from the National Transportation Safety Board to conduct training that incorporates stalls that are fully developed and develop simulator standards to support such training. In 2010, Congress responded to this accident with Public Law 11-216 (Section 208), which mandates full stall training for Part 121 flight operations. Efforts are currently in progress to develop recommendations on implementation of stall training for airline pilots. The International Committee on Aviation Training in Extended Envelopes (ICATEE) is currently defining simulator fidelity standards that will be necessary for effective stall training. These recommendations will apply to all civil transport aircraft including straight-wing turboprop aircraft. Government-funded research over the previous decade provides a strong foundation for stall/post-stall simulation for swept-wing, conventional tail jets to respond to this mandate, but turboprops present additional and unique modeling challenges. First among these challenges is the effect of power, which can provide enhanced flow attachment behind the propellers. Furthermore, turboprops tend to operate for longer periods in an environment more susceptible to ice. As a result, there have been a significant number of turboprop accidents as a result of the early (lower angle of attack) stalls in icing. The vulnerability of turboprop configurations to icing has led to studies on ice accumulation and the resulting effects on flight behavior. Piloted simulations of these effects have highlighted the important training needs for recognition and mitigation of icing effects, including the reduction of stall margins

  4. 19 CFR 10.183 - Duty-free entry of civil aircraft, aircraft engines, ground flight simulators, parts, components...

    Science.gov (United States)

    2010-04-01

    ... ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. General Provisions Civil Aircraft § 10.183... merchandise under a provision for which the rate of duty “Free (C)” appears in the “Special” subcolumn of the... paragraph will be without interest, notwithstanding the provision of 19 U.S.C. 1505(c). (g) Verification...

  5. Simulation and Flight Evaluation of a Parameter Estimation Input Design Method for Hybrid-Wing-Body Aircraft

    Science.gov (United States)

    Taylor, Brian R.; Ratnayake, Nalin A.

    2010-01-01

    As part of an effort to improve emissions, noise, and performance of next generation aircraft, it is expected that future aircraft will make use of distributed, multi-objective control effectors in a closed-loop flight control system. Correlation challenges associated with parameter estimation will arise with this expected aircraft configuration. Research presented in this paper focuses on addressing the correlation problem with an appropriate input design technique and validating this technique through simulation and flight test of the X-48B aircraft. The X-48B aircraft is an 8.5 percent-scale hybrid wing body aircraft demonstrator designed by The Boeing Company (Chicago, Illinois, USA), built by Cranfield Aerospace Limited (Cranfield, Bedford, United Kingdom) and flight tested at the National Aeronautics and Space Administration Dryden Flight Research Center (Edwards, California, USA). Based on data from flight test maneuvers performed at Dryden Flight Research Center, aerodynamic parameter estimation was performed using linear regression and output error techniques. An input design technique that uses temporal separation for de-correlation of control surfaces is proposed, and simulation and flight test results are compared with the aerodynamic database. This paper will present a method to determine individual control surface aerodynamic derivatives.

  6. A simulation method of aircraft plumes for real-time imaging

    Science.gov (United States)

    Li, Ni; Lv, Zhenhua; Huai, Wenqin; Gong, Guanghong

    2016-07-01

    Real-time infrared simulation technology can provide a large number of infrared images under different conditions to support the design, test and evaluation of a system having infrared imaging equipment with very low costs. By synthesizing heat transfer, infrared physics, fluid mechanics and computer graphics, a real-time infrared simulation method is proposed based on the method of characteristics to predict the infrared feature of aircraft plumes, which tries to obtain a good balance between simulation precision and computation efficiency. The temperature and pressure distribution in the under-expansion status can be rapidly solved with dynamically changing flight statuses and engine working states. And a modified C-G (Curtis-Godson) spectral band model that combines the plume streamlines with the conventional C-G spectral band model was implemented to calculate the non-uniformly distributed radiation parameters inside a plume field. The simulation result was analyzed and compared with the CFD++, which validates the credibility and efficiency of the proposed simulation method.

  7. Lessons Learned from Numerical Simulations of the F-16XL Aircraft at Flight Conditions

    Science.gov (United States)

    Rizzi, Arthur; Jirasek, Adam; Lamar, John; Crippa, Simone; Badcock, Kenneth; Boelens, Oklo

    2009-01-01

    Nine groups participating in the Cranked Arrow Wing Aerodynamics Project International (CAWAPI) project have contributed steady and unsteady viscous simulations of a full-scale, semi-span model of the F-16XL aircraft. Three different categories of flight Reynolds/Mach number combinations were computed and compared with flight-test measurements for the purpose of code validation and improved understanding of the flight physics. Steady-state simulations are done with several turbulence models of different complexity with no topology information required and which overcome Boussinesq-assumption problems in vortical flows. Detached-eddy simulation (DES) and its successor delayed detached-eddy simulation (DDES) have been used to compute the time accurate flow development. Common structured and unstructured grids as well as individually-adapted unstructured grids were used. Although discrepancies are observed in the comparisons, overall reasonable agreement is demonstrated for surface pressure distribution, local skin friction and boundary velocity profiles at subsonic speeds. The physical modeling, steady or unsteady, and the grid resolution both contribute to the discrepancies observed in the comparisons with flight data, but at this time it cannot be determined how much each part contributes to the whole. Overall it can be said that the technology readiness of CFD-simulation technology for the study of vehicle performance has matured since 2001 such that it can be used today with a reasonable level of confidence for complex configurations.

  8. A One Dimensional, Time Dependent Inlet/Engine Numerical Simulation for Aircraft Propulsion Systems

    Science.gov (United States)

    Garrard, Doug; Davis, Milt, Jr.; Cole, Gary

    1999-01-01

    The NASA Lewis Research Center (LeRC) and the Arnold Engineering Development Center (AEDC) have developed a closely coupled computer simulation system that provides a one dimensional, high frequency inlet/engine numerical simulation for aircraft propulsion systems. The simulation system, operating under the LeRC-developed Application Portable Parallel Library (APPL), closely coupled a supersonic inlet with a gas turbine engine. The supersonic inlet was modeled using the Large Perturbation Inlet (LAPIN) computer code, and the gas turbine engine was modeled using the Aerodynamic Turbine Engine Code (ATEC). Both LAPIN and ATEC provide a one dimensional, compressible, time dependent flow solution by solving the one dimensional Euler equations for the conservation of mass, momentum, and energy. Source terms are used to model features such as bleed flows, turbomachinery component characteristics, and inlet subsonic spillage while unstarted. High frequency events, such as compressor surge and inlet unstart, can be simulated with a high degree of fidelity. The simulation system was exercised using a supersonic inlet with sixty percent of the supersonic area contraction occurring internally, and a GE J85-13 turbojet engine.

  9. THE APPLICATION OF ASSIMILATED AIRCRAFT DATA IN SIMULATING A HEAVY RAIN OVER SOUTH CHINA IN JUNE 2005

    Institute of Scientific and Technical Information of China (English)

    LIANG Ke; WAN Qi-lin; DING Wei-yu; CHEN Zi-tong; HUANG Yan-yan

    2007-01-01

    Regular and irregular observational data are used to analyze and simulate a torrential rain over the south of China on 18 - 24 June 2005. Since the regular data cannot depict the rainfall system fully,GRAPES model is used to simulate this process. Different data are assimilated for 12 hours by its simulating system and different analysis data are obtained. In order to analyze how well the model forecast has been improved with the addition of assimilated aircraft data, these different analysis data are used as the first-guess data to conduct two control numerical simulation tests. From these tests, it is proved that the model that adds aircraft assimilation data can simulate the main region of precipitation, which is more consistent with the observed precipitation than the model that does not, and that the accuracy rate is also improved. These numerical simulation tests not only show that it is necessary and capable to improve the modeling of this torrential rain process by using aircraft data, but also lays the foundation for forecasting heavy rains in the south of China based on aircraft data.

  10. 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

  11. Piloted simulation study of an ILS approach of a twin-pusher business/commuter turboprop aircraft configuration

    Science.gov (United States)

    Riley, Donald R.; Brandon, Jay M.; Glaab, Louis J.

    1994-01-01

    A six-degree-of-freedom nonlinear simulation of a twin-pusher, turboprop business/commuter aircraft configuration representative of the Cessna ATPTB (Advanced turboprop test bed) was developed for use in piloted studies with the Langley General Aviation Simulator. The math models developed are provided, simulation predictions are compared with with Cessna flight-test data for validation purposes, and results of a handling quality study during simulated ILS (instrument landing system) approaches and missed approaches are presented. Simulated flight trajectories, task performance measures, and pilot evaluations are presented for the ILS approach and missed-approach tasks conducted with the vehicle in the presence of moderate turbulence, varying horizontal winds and engine-out conditions. Six test subjects consisting of two research pilots, a Cessna test pilot, and three general aviation pilots participated in the study. This effort was undertaken in cooperation with the Cessna Aircraft Company.

  12. Products of Ozone-Initiated Chemistry in a Simulated Aircraft Environment

    DEFF Research Database (Denmark)

    Wisthaler, Armin; Tamás, Gyöngyi; Wyon, David P.

    2005-01-01

    ), cabin plus ozone, cabin plus soiled T-shirts (surrogates for human occupants), and cabin plus soiled T-shirts plus ozone. The addition of ozone to the cabin without T-shirts, at concentrations typically encountered during commercial air travel, increased the mixing ratio (v:v concentration) of detected......We used proton-transfer-reaction mass spectrometry (PTR-MS) to examine the products formed when ozone reacted with the materials in a simulated aircraft cabin, including a loaded high-efficiency particulate air (HEPA) filter in the return air system. Four conditions were examined: cabin (baseline...... pollutants from 35 ppb to 80 ppb. Most of this increase was due to the production of saturated and unsaturated aldehydes and tentatively identified low-molecular-weight carboxylic acids. The addition of soiled T-shirts, with no ozone present, increased the mixing ratio of pollutants in the cabin air only...

  13. Inviscid and viscous flow modelling of complex aircraft configurations using the CFD simulation system sauna

    Science.gov (United States)

    Peace, Andrew J.; May, Nicholas E.; Pocock, Mark F.; Shaw, Jonathon A.

    1994-04-01

    This paper is concerned with the flow modelling capabilities of an advanced CFD simulation system known by the acronym SAUNA. This system is aimed primarily at complex aircraft configurations and possesses a unique grid generation strategy in its use of block-structured, unstructured or hybrid grids, depending on the geometric complexity of the addressed configuration. The main focus of the paper is in demonstrating the recently developed multi-grid, block-structured grid, viscous flow capability of SAUNA, through its evaluation on a number of configurations. Inviscid predictions are also presented, both as a means of interpreting the viscous results and with a view to showing more completely the capabilities of SAUNA. It is shown that accuracy and flexibility are combined in an efficient manner, thus demonstrating the value of SAUNA in aerodynamic design.

  14. Augmented Reality in a Simulated Tower Environment: Effect of Field of View on Aircraft Detection

    Science.gov (United States)

    Ellis, Stephen R.; Adelstein, Bernard D.; Reisman, Ronald J.; Schmidt-Ott, Joelle R.; Gips, Jonathan; Krozel, Jimmy; Cohen, Malcolm (Technical Monitor)

    2002-01-01

    An optical see-through, augmented reality display was used to study subjects' ability to detect aircraft maneuvering and landing at the Dallas Ft. Worth International airport in an ATC Tower simulation. Subjects monitored the traffic patterns as if from the airport's western control tower. Three binocular fields of view (14 deg, 28 deg and 47 deg) were studied in an independent groups' design to measure the degradation in detection performance associated with the visual field restrictions. In a second experiment the 14 deg and 28 deg fields were presented either with 46% binocular overlap or 100% overlap for separate groups. The near asymptotic results of the first experiment suggest that binocular fields of view much greater than 47% are unlikely to dramatically improve performance; and those of the second experiment suggest that partial binocular overlap is feasible for augmented reality displays such as may be used for ATC tower applications.

  15. The role of ions in the formation and evolution of particles in aircraft plumes

    Science.gov (United States)

    Yu, Fangqun; Turco, Richard P.

    We consider the effects on aircraft plume microphysics of ions generated by chemiionization processes within the engine combustors. Ions provide centers around which molecular clusters rapidly coalesce, thus promoting the formation of electrically charged sulfuric acid/water aerosols. The resulting charged micro-particles exhibit enhanced growth due to condensation and coagulation aided by electrostatic effects. Simulations with a plume microphysics code show that volatile particles observed behind aircraft may be explained by such processes, as long as initial ion concentrations in the exhaust exceed ˜108/cm³. This analysis also suggests that the primary emissions of sulfuric acid (plus sulfur trioxide) should amount to at least 20-30% of the fuel sulfur to explain the observed number of volatile particles >9 nm in diameter. Ionized plume simulations reveal a distinct bimodal aerosol distribution, in which an “ion” mode constitutes the larger “activated” volatile sulfuric acid particles, while a smaller “neutral” mode comprises the residual slowly-growing neutral molecular clusters formed in the highly supersaturated region of the plume.

  16. An Analog Implementation of Fixed-Wing Lateral/Directional Dynamics and Guidelines on Aircraft Simulations in the Engineering Laboratory.

    Science.gov (United States)

    Karayanakis, Nicholas M.

    1985-01-01

    Describes a scheme for the mechanization of fixed-wing, lateral/directional dynamics as demonstrated on the EAI 580 analog/hybrid system. A review of the complete six degrees of freedom program is included, along with useful guidelines of aircraft simulation in the engineering laboratory. (Author/JN)

  17. Products of Ozone-initiated Chemistry during 4-hour Exposures of Human Subjects in a Simulated Aircraft Cabin

    DEFF Research Database (Denmark)

    Weschler, Charles J.; Wisthaler, Armin; Tamás, Gyöngyi

    2006-01-01

    Proton-transfer-reaction mass spectrometry (PTR-MS) was used to examine organic compounds in the air of a simulated aircraft cabin under four conditions: low ozone, low air exchange rate; low ozone, high air exchange rate; high ozone, low air exchange rate; high ozone, high air exchange rate...

  18. Products of Ozone-initiated Chemistry during 4-hour Exposures of Human Subjects in a Simulated Aircraft Cabin

    DEFF Research Database (Denmark)

    Weschler, Charles J.; Wisthaler, Armin; Tamás, Gyöngyi;

    2006-01-01

    Proton-transfer-reaction mass spectrometry (PTR-MS) was used to examine organic compounds in the air of a simulated aircraft cabin under four conditions: low ozone, low air exchange rate; low ozone, high air exchange rate; high ozone, low air exchange rate; high ozone, high air exchange rate...

  19. Multi-Domain Modeling and Simulation of an Aircraft System for Advanced Vehicle-Level Reasoning Research and Development

    Directory of Open Access Journals (Sweden)

    : F. Khan

    2014-05-01

    Full Text Available In this paper, we describe a simulation based health monitoring system test-bed for aircraft systems. The purpose of the test-bed is to provide a technology neutral basis for implementing and evaluation of reasoning systems on vehicle level and software architecture in support of the safety and maintenance process. This simulation test-bed will provide the sub-system level results and data which can be fed to the VLRS to generate vehicle level reasoning to achieve broader level diagnoses. This paper describes real-time system architecture and concept of operations for the aircraft major sub-systems. The four main components in the real-time test-bed are the aircraft sub-systems (e.g. battery, fuel, engine, generator, heating and lighting system simulation model, fault insertion unit, health monitoring data processing and user interface. In this paper, we adopted a component based modelling paradigm for the implementation of the virtual aircraft systems. All of the fault injections are currently implemented via software. The fault insertion unit allows for the repeatable injection of faults into the system. The simulation test-bed has been tested with many different faults which were undetected on system level to process and detect on the vehicle level reasoning. This article also shows how one system fault can affect the overall health of the vehicle.

  20. Real-Time Simulation Computation System. [for digital flight simulation of research aircraft

    Science.gov (United States)

    Fetter, J. L.

    1981-01-01

    The Real-Time Simulation Computation System, which will provide the flexibility necessary for operation in the research environment at the Ames Research Center is discussed. Designing the system with common subcomponents and using modular construction techniques enhances expandability and maintainability qualities. The 10-MHz series transmission scheme is the basis of the Input/Output Unit System and is the driving force providing the system flexibility. Error checking and detection performed on the transmitted data provide reliability measurements and assurances that accurate data are received at the simulators.

  1. Finite Element Simulation of Three Full-Scale Crash Tests for Cessna 172 Aircraft

    Science.gov (United States)

    Mason, Brian H.; Warren, Jerry E., Jr.

    2017-01-01

    The NASA Emergency Locator Transmitter Survivability and Reliability (ELT-SAR) project was initiated in 2013 to assess the crash performance standards for the next generation of emergency locator transmitter (ELT) systems. Three Cessna 172 aircraft were acquired to perform crash testing at NASA Langley Research Center's Landing and Impact Research Facility. Full-scale crash tests were conducted in the summer of 2015 and each test article was subjected to severe, but survivable, impact conditions including a flare-to-stall during emergency landing, and two controlled-flight-into-terrain scenarios. Full-scale finite element analyses were performed using a commercial explicit solver, ABAQUS. The first test simulated impacting a concrete surface represented analytically by a rigid plane. Tests 2 and 3 simulated impacting a dirt surface represented analytically by an Eulerian grid of brick elements using a Mohr-Coulomb material model. The objective of this paper is to summarize the test and analysis results for the three full-scale crash tests. Simulation models of the airframe which correlate well with the tests are needed for future studies of alternate ELT mounting configurations.

  2. Aircraft observations and model simulations of concentration and particle size distribution in the Eyjafjallajökull volcanic ash cloud

    Science.gov (United States)

    Dacre, H. F.; Grant, A. L. M.; Johnson, B. T.

    2013-02-01

    The Eyjafjallajökull volcano in Iceland emitted a cloud of ash into the atmosphere during April and May 2010. Over the UK the ash cloud was observed by the FAAM BAe-146 Atmospheric Research Aircraft which was equipped with in-situ probes measuring the concentration of volcanic ash carried by particles of varying sizes. The UK Met Office Numerical Atmospheric-dispersion Modelling Environment (NAME) has been used to simulate the evolution of the ash cloud emitted by the Eyjafjallajökull volcano during the period 4-18 May 2010. In the NAME simulations the processes controlling the evolution of the concentration and particle size distribution include sedimentation and deposition of particles, horizontal dispersion and vertical wind shear. For travel times between 24 and 72 h, a 1/t relationship describes the evolution of the concentration at the centre of the ash cloud and the particle size distribution remains fairly constant. Although NAME does not represent the effects of microphysical processes, it can capture the observed decrease in concentration with travel time in this period. This suggests that, for this eruption, microphysical processes play a small role in determining the evolution of the distal ash cloud. Quantitative comparison with observations shows that NAME can simulate the observed column-integrated mass if around 4% of the total emitted mass is assumed to be transported as far as the UK by small particles (< 30 μm diameter). NAME can also simulate the observed particle size distribution if a distal particle size distribution that contains a large fraction of < 10 μm diameter particles is used, consistent with the idea that phraetomagmatic volcanoes, such as Eyjafjallajökull, emit very fine particles.

  3. Aircraft observations and model simulations of concentration and particle size distribution in the Eyjafjallajökull volcanic ash cloud

    Directory of Open Access Journals (Sweden)

    H. F. Dacre

    2013-02-01

    Full Text Available The Eyjafjallajökull volcano in Iceland emitted a cloud of ash into the atmosphere during April and May 2010. Over the UK the ash cloud was observed by the FAAM BAe-146 Atmospheric Research Aircraft which was equipped with in-situ probes measuring the concentration of volcanic ash carried by particles of varying sizes. The UK Met Office Numerical Atmospheric-dispersion Modelling Environment (NAME has been used to simulate the evolution of the ash cloud emitted by the Eyjafjallajökull volcano during the period 4–18 May 2010. In the NAME simulations the processes controlling the evolution of the concentration and particle size distribution include sedimentation and deposition of particles, horizontal dispersion and vertical wind shear. For travel times between 24 and 72 h, a 1/t relationship describes the evolution of the concentration at the centre of the ash cloud and the particle size distribution remains fairly constant. Although NAME does not represent the effects of microphysical processes, it can capture the observed decrease in concentration with travel time in this period. This suggests that, for this eruption, microphysical processes play a small role in determining the evolution of the distal ash cloud. Quantitative comparison with observations shows that NAME can simulate the observed column-integrated mass if around 4% of the total emitted mass is assumed to be transported as far as the UK by small particles (< 30 μm diameter. NAME can also simulate the observed particle size distribution if a distal particle size distribution that contains a large fraction of < 10 μm diameter particles is used, consistent with the idea that phraetomagmatic volcanoes, such as Eyjafjallajökull, emit very fine particles.

  4. Aircraft observations and model simulations of concentration and particle size distribution in the Eyjafjallajökull volcanic ash cloud

    Directory of Open Access Journals (Sweden)

    H. F. Dacre

    2012-09-01

    Full Text Available The Eyjafjallajökull volcano in Iceland emitted a cloud of ash into the atmosphere during April and May 2010. Over the UK the ash cloud was observed by the FAAM BAe-146 Atmospheric Research Aircraft which was equipped with in-situ probes measuring the concentration of volcanic ash carried by particles of varying sizes. The UK Met Office Numerical Atmospheric-dispersion Modelling Environment (NAME has been used to simulate the evolution of the ash cloud emitted by the Eyjafjallajökull volcano during the period 4–18 May 2010. In the NAME simulations the processes controlling the evolution of the concentration and particle size distribution include sedimentation and deposition of particles, horizontal dispersion and vertical wind shear. For travel times between 24 and 72 h a 1/t relationship describes the evolution of the concentration at the centre of the ash cloud and the particle size distribution remains fairly constant. Although NAME does not represent the effects of microphysical processes it can capture the observed decrease in concentration with travel time in this period. This suggests that, for this eruption, microphysical processes play a small role in determining the evolution of the distal ash cloud. Quantitative comparison with observations shows that NAME can simulate the observed column integrated mass if around 4% of the total emitted mass is assumed to be transported as far as the UK by small (<30 m diameter particles. NAME can also simulate the observed particle size distribution if a distal particle size distribution that contains a large fraction of <10 m diameter particles is used, consistent with the idea that phraetomagmatic volcanoes, such as Eyjafjallajökull, emit very fine particles.

  5. Large Eddy Simulation of Aircraft Wake Vortices in a Homogeneous Atmospheric Turbulence: Vortex Decay and Descent

    Science.gov (United States)

    Han, Jongil; Lin, Yuh-Lang; Arya, S. Pal; Proctor, Fred H.

    1999-01-01

    The effects of ambient turbulence on decay and descent of aircraft wake vortices are studied using a validated, three-dimensional: large-eddy simulation model. Numerical simulations are performed in order to isolate the effect of ambient turbulence on the wake vortex decay rate within a neutrally-stratified atmosphere. Simulations are conducted for a range of turbulence intensities, by injecting wake vortex pairs into an approximately homogeneous and isotropic turbulence field. The decay rate of the vortex circulation increases clearly with increasing ambient turbulence level, which is consistent with field observations. Based on the results from the numerical simulations, simple decay models are proposed as functions of dimensionless ambient turbulence intensity (eta) and dimensionless time (T) for the circulation averaged over a range of radial distances. With good agreement with the numerical results, a Gaussian type of vortex decay model is proposed for weak turbulence: while an exponential type of Tortex decay model can be applied for strong turbulence. A relationship for the vortex descent based on above vortex decay model is also proposed. Although the proposed models are based on simulations assuming neutral stratification, the model predictions are compared to Lidar vortex measurements observed during stable, neutral, and unstable atmospheric conditions. In the neutral and unstable atmosphere, the model predictions appear to be in reasonable agreement with the observational data, while in the stably-stratified atmosphere, they largely underestimate the observed circulation decay with consistent overestimation of the observed vortex descent. The underestimation of vortex decay during stably-stratified conditions suggests that stratification has an important influence on vortex decay when ambient levels of turbulence are weak.

  6. Simulation and simulator development of a separate surface attitude command control system for light aircraft

    Science.gov (United States)

    Roskam, J.

    1976-01-01

    A detailed description is presented of the simulation philosophy and process used in the development of a Separate Surface Attitude Command control system (SSAC) for a Beech Model 99 Airliner. The intent of this system is to provide complete three axes stability augmentation at low cost and without the need for system redundancy. The system, although aimed at the general aviation market, also has applications to certain military airplanes as well as to miniature submarines.

  7. Parabolic Flights with Single-Engine Aerobatic Aircraft: Flight Profile and a Computer Simulator for its Optimization

    Science.gov (United States)

    Brigos, Miguel; Perez-Poch, Antoni; Alpiste, Francesc; Torner, Jordi; González Alonso, Daniel Ventura

    2014-11-01

    We report the results of residual acceleration obtained from initial tests of parabolic flights (more than 100 hours) performed with a small single-engine aerobatic aircraft (CAP10B), and propose a method that improves these figures. Such aircraft have proved capable of providing researchers with periods of up to 8 seconds of reduced gravity in the cockpit, with a gravity quality in the range of 0.1 g 0, where g 0 is the gravitational acceleration of the Earth. Such parabolas may be of interest to experimenters in the reduced gravity field, when this range of reduced gravity is acceptable for the experiment undertaken. They have also proven to be useful for motivational and educational campaigns. Furthermore, these flights may be of interest to researchers as a test-bed for obtaining a proof-of-concept for subsequent access to parabolic flights with larger aircraft or other microgravity platforms. The limited cost of the operations with these small aircraft allows us to perform them as part of a non-commercial joint venture between the Universitat Politècnica de Catalunya - BarcelonaTech (UPC), the Barcelona cluster BAIE and the Aeroclub Barcelona-Sabadell. Any improvements in the length and quality of reduced gravity would increase the capabilities of these small aircraft. To that end, we have developed a method based on a simulator for training aerobatic pilots. The simulation is performed with the CAD software for mechanical design Solidworks Motion{circledR }, which is widely distributed in industry and in universities. It specifically simulates the parabolic flight manoeuvre for our small aircraft and enables us to improve different aspects of the manoeuvre. The simulator is first validated with experimental data from the test flights. We have conducted an initial intensive period of specific pilot training with the aid of the simulator output. After such initial simulation-aided training, results show that the reduced gravity quality has significantly

  8. Local Impact Simulation of SC Wall Structures using Aircraft Engine Projectile

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Chulhun; Lee, Jungwhee; Lee, Hanjoo [Dankook Univ., Yongin (Korea, Republic of); Jung, Raeyoung; Hyun, Changhun [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2013-05-15

    SC wall structure developed for nuclear power plant buildings consists of plain concrete and two steel plates on both surface of the concrete, while RC structure consists of re bar and concrete. SC structure has higher scabbing resistance than RC structure due to the action of steel plate on the rear side of impact. Therefore SC structure is known as more effective structure from the viewpoint of aircraft crash than RC structure. However, most of the recent researches and experiments about local impact damage deal with RC structures, and the effect of re bar and steel plate is not considered reasonably. Although Walter et al. and Make-work et al. suggested a formula for evaluating perforation depth of steel plate covered RC walls, most of the previous researches about SC structure are focused on perforation and scabbing due to the impact of hard projectile, rather than soft projectile such as an aircraft. In this research a soft projectile, i. e. aircraft engine, is utilized for impact simulation of RC and SC walls. To evaluate local damage of SC wall structures, parametric study with the variables of wall thickness and steel ratio of the cover plate is performed, and the results are compared with those of RC structures. Since scabbing was prevented by the steel plates, penetration mode of damage was observed in SC walls while scabbing damage was occurred in RC walls. It is confirmed that the rear steel plate not only contains concrete debris, but also reduces the internal damage of the concrete walls. Penetration depth of SC walls did not largely vary due to the increasing steel ratio, and similar results to RC walls were observed when the wall thickness is larger than a certain value since the impact resistance of SC wall is mainly governed by the thickness of concrete part. Therefore, it is expected that similar level of impact resistance to RC structure can be produced with the minimum thickness of steel plates of SC structure. According to these results, SC

  9. 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.

  10. Utilizing High Fidelity Simulations in Multidisciplinary Optimization of Aircraft Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Aircraft design is a complex process requiring interactions and exchange of information among multiple disciplines such as aerodynamics, strength, fatigue, controls,...

  11. High fidelity simulation of non-synchronous vibration for aircraft engine fan/compressor

    Science.gov (United States)

    Im, Hong-Sik

    The objectives of this research are to develop a high fidelity simulation methodology for turbomachinery aeromechanical problems and to investigate the mechanism of non-synchronous vibration (NSV) of an aircraft engine axial compressor. A fully conservative rotor/stator sliding technique is developed to accurately capture the unsteadiness and interaction between adjacent blade rows. Phase lag boundary conditions (BC) based on the time shift (direct store) method and the Fourier series phase lag BC are implemented to take into account the effect of phase difference for a sector of annulus simulation. To resolve the nonlinear interaction between flow and vibrating blade structure, a fully coupled fluid-structure interaction (FSI) procedure that solves the structural modal equations and time accurate Navier-Stokes equations simultaneously is adopted. An advanced mesh deformation method that generates the blade tip block mesh moving with the blade displacement is developed to ensure the mesh quality. An efficient and low diffusion E-CUSP (LDE) scheme as a Riemann solver designed to minimize numerical dissipation is used with an improved hybrid RANS/LES turbulence strategy, delayed detached eddy simulation (DDES). High order accuracy (3rd and 5th order) weighted essentially non-oscillatory (WENO) schemes for inviscid flux and a conservative 2nd and 4th order viscous flux differencing are employed. Extensive validations are conducted to demonstrate high accuracy and robustness of the high fidelity FSI simulation methodology. The validated cases include: (1) DDES of NACA 0012 airfoil at high angle of attack with massive separation. The DDES accurately predicts the drag whereas the URANS model significantly over predicts the drag. (2) The AGARD Wing 445.6 flutter boundary is accurately predicted including the point at supersonic incoming flow. (3) NASA Rotor 67 validation for steady state speed line and radial profiles at peak efficiency point and near stall point. The

  12. Correlation between subjective assessments of local thermal discomfort and thermal manikin measurements in a simulated aircraft cabin

    DEFF Research Database (Denmark)

    Zukowska, Daria; Strøm-Tejsen, Peter; Jama, Agnieszka

    2005-01-01

    The thermal environment in a 21-seat simulated section of an aircraft cabin installed in a climate chamber was investigated. Using two thermal manikins and fourteen heated cylin-ders to represent passengers, measurements were carried out at cabin temperatures of 20.6°C, 23.3°C and 26.1°C (69°F, 74...

  13. A comparison of aircraft tire skid with initial wheel\\ud rotational speed using ANSYS transient simulation

    OpenAIRE

    Alroqi, Abdurrhman A; Wang, Weiji

    2016-01-01

    Based on heavy aircraft main landing gear tires touchdown skidding process, patents have been registered since the 1940s to improve tire safety, decrease the substantial wear and smoke that results from every landing by spinning the rear wheels before touchdown. A single wheel has been modeled as a mass-spring-damper system using ANSYS mechanical transient simulation to analyze static and pre-rotating wheels behavior during a short period between touchdown and skidding, to spin-up to reach th...

  14. Resistance ability evaluation of safety-related structures for the simulated aircraft accident

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Jin; Kim, Sung Woon; Choi, Jang Kyu [Daewoo E and C Co., Ltd., Suwon (Korea, Republic of)] (and others)

    2003-03-15

    Aircraft accidents on nuclear safety-related structures can cause severe damage to the safety of NPP(Nuclear Power Plant)s. To assess the safety of nuclear safety-related structures, the local damage and the dynamic response of global structures should be investigated together. This study have compared several local damage assessment formulas suggested for aircraft as an impactor, and have set the assessment system of local damage for impact-proof design of NPP containment buildings. And the local damage of nuclear safety-related structures in operation in Korea for commercial aircraft as impactor have been estimated. Impact load-time functions of the aircraft crash have been decided to assessment the safety of nuclear safety-related structures against the intentional colliding of commercial aircraft. Boeing 747 and Boeing 767 is selected as target aircraft based on the operation frequencies and weights. Comparison of the fire analysis methods showed that the method considering heat convection and radiation is adequate for the temperature analysis of the aircraft fuel fire. Finally, the study covered the analysis of the major structural drawings and design drawings with which three-dimensional finite element model analysis is expected to be performed.

  15. Investigation on aerodynamic characteristics of baseline-II E-2 blended wing-body aircraft with canard via computational simulation

    Science.gov (United States)

    Nasir, Rizal E. M.; Ali, Zurriati; Kuntjoro, Wahyu; Wisnoe, Wirachman

    2012-06-01

    Previous wind tunnel test has proven the improved aerodynamic charasteristics of Baseline-II E-2 Blended Wing-Body (BWB) aircraft studied in Universiti Teknologi Mara. The E-2 is a version of Baseline-II BWB with modified outer wing and larger canard, solely-designed to gain favourable longitudinal static stability during flight. This paper highlights some results from current investigation on the said aircraft via computational fluid dynamics simulation as a mean to validate the wind tunnel test results. The simulation is conducted based on standard one-equation turbulence, Spalart-Allmaras model with polyhedral mesh. The ambience of the flight simulation is made based on similar ambience of wind tunnel test. The simulation shows lift, drag and moment results to be near the values found in wind tunnel test but only within angles of attack where the lift change is linear. Beyond the linear region, clear differences between computational simulation and wind tunnel test results are observed. It is recommended that different type of mathematical model be used to simulate flight conditions beyond linear lift region.

  16. A Model Stitching Architecture for Continuous Full Flight-Envelope Simulation of Fixed-Wing Aircraft and Rotorcraft from Discrete Point Linear Models

    Science.gov (United States)

    2016-04-01

    aircraft mass to obtain the dimensional gravity forces: F grav = XgravYgrav Zgrav  = X̄gravȲgrav Z̄grav msim (2.45) The current simulation value ...simulation model. off-nominal An off-nominal configuration is an aircraft loading configuration with values of aircraft mass, inertia, and/or center of gravity ...CG) location that differ from the identified/baseline values . relinearize To obtain a state-space representation (and the corresponding stability

  17. Damage Propagation Modeling for Aircraft Engine Run-to-Failure Simulation

    Data.gov (United States)

    National Aeronautics and Space Administration — This paper describes how damage propagation can be modeled within the modules of aircraft gas turbine engines. To that end, response surfaces of all sensors are...

  18. Soil moisture characterization of the Valencia anchor station. Ground, aircraft measurements and simulations

    DEFF Research Database (Denmark)

    Lopez-Baeza, E; Antolin, M C; Balling, Jan E.

    2009-01-01

    , soil type, lithology, geology, elevation, slope and vegetation cover conditions. Complementary to the ground measurements, flight operations were performed over this control area using the Helsinki University of Technology TKK Short Skyvan research aircraft which contained onboard a payload constituted...

  19. Remote sensing with simulated unmanned aircraft imagery for precision agriculture applications

    Science.gov (United States)

    Hunt, E. Raymond; Daughtry, Craig S.T.; Mirsky, Steven B.; Hively, W. Dean

    2014-01-01

    An important application of unmanned aircraft systems (UAS) may be remote-sensing for precision agriculture, because of its ability to acquire images with very small pixel sizes from low altitude flights. The objective of this study was to compare information obtained from two different pixel sizes, one about a meter (the size of a small vegetation plot) and one about a millimeter. Cereal rye (Secale cereale) was planted at the Beltsville Agricultural Research Center for a winter cover crop with fall and spring fertilizer applications, which produced differences in biomass and leaf chlorophyll content. UAS imagery was simulated by placing a Fuji IS-Pro UVIR digital camera at 3-m height looking nadir. An external UV-IR cut filter was used to acquire true-color images; an external red cut filter was used to obtain color-infrared-like images with bands at near-infrared, green, and blue wavelengths. Plot-scale Green Normalized Difference Vegetation Index was correlated with dry aboveground biomass ( ${mbi {r}} = 0.58$ ), whereas the Triangular Greenness Index (TGI) was not correlated with chlorophyll content. We used the SamplePoint program to select 100 pixels systematically; we visually identified the cover type and acquired the digital numbers. The number of rye pixels in each image was better correlated with biomass ( ${mbi {r}} = 0.73$ ), and the average TGI from only leaf pixels was negatively correlated with chlorophyll content ( ${mbi {r}} = -0.72$ ). Thus, better information for crop requirements may be obtained using very small pixel sizes, but new algorithms based on computer vision are needed for analysis. It may not be necessary to geospatially register large numbers of photographs with very small pixel sizes. Instead, images could be analyzed as single plots along field transects.

  20. Investigation of Turbulence Effect on Dynamic Behaviour of Aircraft Through Use of JDYNASIM: A Platform Independent Simulation Software

    Directory of Open Access Journals (Sweden)

    D. P. Coiro

    2000-01-01

    Full Text Available The need of fast and interactive tool to simulate aircraft behaviour is a demand of modern technology. This necessity is more evident when light aircraft and sailplanes are involved.. This paper presents an attempt to give simulation possibility almost to everyone through the use of JDynaSim code, written to meet this goal. JDynaSim is an interactive graphic flight simulation code written in JAVA and VRML languages which practically allows everyone to fly the aeroplane under investigation. This is true due to the fact that JAVA is a language born to work under a generic Internet browser (such as Microsoft Explorer or Netscape and thus it is independent from the operating system under which it is running. Dynamic motion equations are solved by 12 ordinary non-linear differential equations in which the non-linear forces are input in multidimensional matrix form and are interpolated at each time instant. Advancing in time is performed using a 4th order Runge-Kutta integration scheme. Translation equations of motion are written in a flight path axis system while rotational equations are written on body axis system. An on-purpose written pre-processor has to be used to transform forces to appropriate reference system. The code can interactively read mouse and keyboard inputs as well as files with command laws assigned in function of time. There is the possibility to record the interactive session performed and then to repeat the manoeuvre. This paper presents also the code extension for simulating the effect of gusts generated according to classical theories. In particular investigation has been performed to compare results coming from classical theories on aircraft responses to gusts inputs respect to those coming from JDynSim flight simulator. JDynaSim is available to everybody through Internet at the following URL: http://www.dpa.unina.it/coiro/

  1. 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.

  2. Evaluation of V/STOL research aircraft design. [landing approaches, propulsion/control, piloted moving base simulator

    Science.gov (United States)

    Deckert, W. H.; Holzhauser, C. A.

    1973-01-01

    The evaluation and evolution of direct jet lift V/STOL transport aircraft designs are discussed. The V/STOL transport design selected as an example is a lift-fan design that was evaluated as a candidate configuration for a possible future V/STOL research transport. The paper includes discussion of potential advanced V/STOL landing approach profiles as key design requirements for V/STOL aircraft, description and experimental results of an integrated propulsion/control system designed to achieve desired advanced V/STOL near-terminal operating capabilities, and results from evaluating V/STOL designs on piloted moving-base simulators. This paper discusses use of the piloted moving-base simulator as a design tool for evolving satisfactory V/STOL stabilization and propulsion/control systems. Included are problems and solutions identified during simulation of simultaneous decelerating/descent steep curved landing approaches under instrument flight conditions. Simulation results are also compared to flight results obtained with the DO-31 V/STOL research transport.

  3. Aircraft Wake Vortex Deformation in Turbulent Atmosphere

    OpenAIRE

    Hennemann, Ingo; Holzaepfel, Frank

    2007-01-01

    Large-scale distortion of aircraft wake vortices appears to play a crucial role for aircraft safety during approach and landing. Vortex distortion is investigated based on large eddy simulations of wake vortex evolution in a turbulent atmosphere. A vortex identification method is developed that can be adapted to the vortex scales of interest. Based on the identified vortex center tracks, a statistics of vortex curvature radii is established. This statistics constitutes the basis for understan...

  4. Towards Simulating Non-Axisymmetric Influences on Aircraft Plumes for Signature Prediction

    Science.gov (United States)

    Kenzakowski, D. C.; Shipman, J. D.; Dash, S. M.

    2000-01-01

    A methodology for efficiently including three-dimensional effects on aircraft plume signature is presented. First, exploratory work on the use of passive mixing enhancement devices, namely chevrons and tabs, in IR signature reduction for external turbofan plumes is demonstrated numerically and experimentally. Such small attachments, when properly designed, cause an otherwise axisymmetric plume to have significant 3D structures, affecting signature prediction. Second, an approach for including non-axisymmetric and installation effects in plume signature prediction is discussed using unstructured methodology. Unstructured flow solvers, using advanced turbulence modeling and plume thermochemistry, facilitate the modeling of aircraft effects on plume structure that previously have been neglected due to gridding complexities. The capabilities of the CRUNCH unstructured Navier-Stokes solver for plume modeling is demonstrated for a passively mixed turbofan nozzle, a generic fighter nozzle, and a complete aircraft.

  5. Creep-fatigue interaction in aircraft gas turbine components by simulation and testing at scaled temperatures

    Science.gov (United States)

    Sabour, Mohammad Hossein

    Advanced gas turbine engines, which use hot section airfoil cooling, present a wide range of design problems. The frequencies of applied loads and the natural frequencies of the blade also are important since they have significant effects on failure of the component due to fatigue phenomenon. Due to high temperature environment the thermal creep and fatigue are quite severe. One-dimensional creep model, using ANSYS has been formulated in order to predict the creep life of a gas turbine engine blade. Innovative mathematical models for the prediction of the operating life of aircraft components, specifically gas turbine blades, which are subjected to creep-fatigue at high temperatures, are proposed. The components are modeled by FEM, mathematically, and using similitude principles. Three models have been suggested and evaluated numerically and experimentally. Using FEM method for natural frequencies causes phenomena such as curve veering which is studied in more detail. The simulation studies on the life-limiting modes of failure, as well as estimating the expected lifetime of the blade, using the proposed models have been carried out. Although the scale model approach has been used for quite some time, the thermal scaling has been used in this study for the first time. The only thermal studies in literature using scaling for structures is by NASA in which materials of both the prototype and the model are the same, but in the present study materials also are different. The finite element method is employed to model the structure. Because of stress redistribution due to the creep process, it is necessary to include a full inelastic creep step in the finite element formulation. Otherwise over-conservative creep life predictions will be estimated if only the initial elastic stresses are considered. The experimental investigations are carried out in order to validate the models. The main contributions in the thesis are: (1) Using similitude theory for life prediction of

  6. Passenger evaluation of the optimum balance between fresh air supply and humidity from 7-h exposures in a simulated aircraft cabin

    DEFF Research Database (Denmark)

    Strøm-Tejsen, Peter; Wyon, David Peter; Lagercrantz, Love Per

    2007-01-01

    A 21-seat section of an aircraft cabin with realistic pollution sources was built inside a climate chamber capable of providing fresh outside air at very low humidity. Maintaining a constant 200 l/s rate of total air supply, i.e. recircu-lated and make-up air, to the cabin, experiments simulating 7....... Analysis of the subjec-tive assessments showed that increasing RH in the aircraft cabin to 28% RH by reducing outside flow to 1.4 l/s per person did not reduce the intensity of the symptoms that are typical of the aircraft cabin environment. On the contrary, it intensified complaints of headache, dizziness...

  7. Aircraft observations and model simulations of concentration and particle size distribution in the Eyjafjallajökull volcanic ash cloud

    OpenAIRE

    Dacre, H. F.; A. L. M. Grant; Johnson, B. T.

    2013-01-01

    The Eyjafjallajökull volcano in Iceland emitted a cloud of ash into the atmosphere during April and May 2010. Over the UK the ash cloud was observed by the FAAM BAe-146 Atmospheric Research Aircraft which was equipped with in-situ probes measuring the concentration of volcanic ash carried by particles of varying sizes. The UK Met Office Numerical Atmospheric-dispersion Modelling Environment (NAME) has been used to simulate the evolution of the ash cloud emitted by the Eyjafjallajökull volcano...

  8. Aircraft observations and model simulations of concentration and particle size distribution in the Eyjafjallajökull volcanic ash cloud

    OpenAIRE

    Dacre, H. F.; A. L. M. Grant; Johnson, B. T.

    2012-01-01

    The Eyjafjallajökull volcano in Iceland emitted a cloud of ash into the atmosphere during April and May 2010. Over the UK the ash cloud was observed by the FAAM BAe-146 Atmospheric Research Aircraft which was equipped with in-situ probes measuring the concentration of volcanic ash carried by particles of varying sizes. The UK Met Office Numerical Atmospheric-dispersion Modelling Environment (NAME) has been used to simulate the evolution of the ash cloud emitted by the Eyjafjallajökull volcano...

  9. Influence of inter-annual variations of stratospheric dynamics in model simulations of ozone losses by aircraft emissions

    Energy Technology Data Exchange (ETDEWEB)

    Jadin, E.A. [Central Aerological Observatory, Dolgoprudny (Russian Federation)

    1997-12-31

    The questions of model predictions of aircraft emission impacts on the ozone variations are considered. Using the NMC data it is shown that the stratospheric circulation underwent the abrupt transition to a new regime in summer 1980. The strong correlations are found between the monthly mean total ozone and stratospheric angular momentum anomalies during 1979-1991. The natural long-term changes of transport processes are necessary to take into account in model simulations of anthropogenic impacts on the ozone layer. (author) 12 refs.

  10. Integrated autopilot/autothrottle for the NASA TSRV B-737 aircraft: Design and verification by nonlinear simulation

    Science.gov (United States)

    Bruce, Kevin R.

    1989-01-01

    An integrated autopilot/autothrottle was designed for flight test on the NASA TSRV B-737 aircraft. The system was designed using a total energy concept and is attended to achieve the following: (1) fuel efficiency by minimizing throttle activity; (2) low development and implementation costs by designing the control modes around a fixed inner loop design; and (3) maximum safety by preventing stall and engine overboost. The control law was designed initially using linear analysis; the system was developed using nonlinear simulations. All primary design requirements were satisfied.

  11. Nuclear Hardness Simulation and Analysis of Composite Aircraft Structures. Volume 2. Dust Erosion Assessment.

    Science.gov (United States)

    1985-12-31

    so from Equation (5) lv (J) At j ) - L ( j ) the distance the aircraft travels through dust with concentration n (j ) . The density of the generic...AFSC ATTN: NTA A SHARP U S ARMY BALLISTIC RESEARCH LAB ATTN: NTATE E FRANKLIN ATTN: S POLYAK ATTN: NTN (NGCS) ATTN: SLCBR-TB-B R RALEY ATTN: SUL U S

  12. RJARS: RAND’s Version of the Jamming Aircraft and Radar Simulation

    Science.gov (United States)

    1991-01-01

    29 C. UPDTR--Over-Terrain Visibility........................ 32 D. UPDRS --Update Search Radars........................... 36 1...179 A.5. Update Searchers ( UPDRS ) Flow Chart ....................... 180 A.6. Update Optical Search and Acquisition Flow Chart...RJARS contains 11 updating modules: 1. UPDCK System clock 2. UPDAC Aircraft positions and maneuvers 3. UPDTR Over-terrain visibility 4. UPDRS Search

  13. Trends in aircraft noise annoyance: The role of study and sample characteristics

    NARCIS (Netherlands)

    Kroesen, M.; Molin, E.J.E.; Miedema, H.M.E.; Vos, H.; Janssen, S.A.; Wee, B. van

    2010-01-01

    This study assesses the effects of aircraft noise on residential satisfaction, an important indicator of subjective well-being. A structural equation model is specified that estimates the relationships between objective variables, noise annoyance variables and residential satisfaction. Secondary

  14. Trends in aircraft noise annoyance: The role of study and sample characteristics

    NARCIS (Netherlands)

    Kroesen, M.; Molin, E.J.E.; Miedema, H.M.E.; Vos, H.; Janssen, S.A.; Wee, B. van

    2010-01-01

    This study assesses the effects of aircraft noise on residential satisfaction, an important indicator of subjective well-being. A structural equation model is specified that estimates the relationships between objective variables, noise annoyance variables and residential satisfaction. Secondary dat

  15. Role of structural noise in aircraft pressure cockpit from vibration action of new-generation engines

    Science.gov (United States)

    Baklanov, V. S.

    2016-07-01

    The evolution of new-generation aircraft engines is transitioning from a bypass ratio of 4-6 to an increased ratio of 8-12. This is leading to substantial broadening of the vibration spectrum of engines with a shift to the low-frequency range due to decreased rotation speed of the fan rotor, in turn requiring new solutions to decrease structural noise from engine vibrations to ensure comfort in the cockpits and cabins of aircraft.

  16. Roles, uses, and benefits of general aviation aircraft in aerospace engineering education

    Science.gov (United States)

    Odonoghue, Dennis P.; Mcknight, Robert C.

    1994-01-01

    Many colleges and universities throughout the United States offer outstanding programs in aerospace engineering. In addition to the fundamentals of aerodynamics, propulsion, flight dynamics, and air vehicle design, many of the best programs have in the past provided students the opportunity to design and fly airborne experiments on board various types of aircraft. Sadly, however, the number of institutions offering such 'airborne laboratories' has dwindled in recent years. As a result, opportunities for students to apply their classroom knowledge, analytical skills, and engineering judgement to the development and management of flight experiments on an actual aircraft are indeed rare. One major reason for the elimination of flight programs by some institutions, particularly the smaller colleges, is the prohibitive cost of operating and maintaining an aircraft as a flying laboratory. The purpose of this paper is to discuss simple, low-cost, relevant flight experiments that can be performed using readily available general aviation aircraft. This paper examines flight experiments that have been successfully conducted on board the NASA Lewis Research Center's T-34B aircraft, as part of the NASA/AIAA/University Flight Experiment Program for Students (NAUFEPS) and discusses how similar experiments could be inexpensively performed on other general aviation aircraft.

  17. Analysis of control system responses for aircraft stability and efficient numerical techniques for real-time simulations

    Science.gov (United States)

    Stroe, Gabriela; Andrei, Irina-Carmen; Frunzulica, Florin

    2017-01-01

    The objectives of this paper are the study and the implementation of both aerodynamic and propulsion models, as linear interpolations using look-up tables in a database. The aerodynamic and propulsion dependencies on state and control variable have been described by analytic polynomial models. Some simplifying hypotheses were made in the development of the nonlinear aircraft simulations. The choice of a certain technique to use depends on the desired accuracy of the solution and the computational effort to be expended. Each nonlinear simulation includes the full nonlinear dynamics of the bare airframe, with a scaled direct connection from pilot inputs to control surface deflections to provide adequate pilot control. The engine power dynamic response was modeled with an additional state equation as first order lag in the actual power level response to commanded power level was computed as a function of throttle position. The number of control inputs and engine power states varied depending on the number of control surfaces and aircraft engines. The set of coupled, nonlinear, first-order ordinary differential equations that comprise the simulation model can be represented by the vector differential equation. A linear time-invariant (LTI) system representing aircraft dynamics for small perturbations about a reference trim condition is given by the state and output equations present. The gradients are obtained numerically by perturbing each state and control input independently and recording the changes in the trimmed state and output equations. This is done using the numerical technique of central finite differences, including the perturbations of the state and control variables. For a reference trim condition of straight and level flight, linearization results in two decoupled sets of linear, constant-coefficient differential equations for longitudinal and lateral / directional motion. The linearization is valid for small perturbations about the reference trim

  18. Wet scavenging of soluble gases in DC3 deep convective storms using WRF-Chem simulations and aircraft observations

    Science.gov (United States)

    Bela, Megan M.; Barth, Mary C.; Toon, Owen B.; Fried, Alan; Homeyer, Cameron R.; Morrison, Hugh; Cummings, Kristin A.; Li, Yunyao; Pickering, Kenneth E.; Allen, Dale J.; Yang, Qing; Wennberg, Paul O.; Crounse, John D.; St. Clair, Jason M.; Teng, Alex P.; O'Sullivan, Daniel; Huey, L. Gregory; Chen, Dexian; Liu, Xiaoxi; Blake, Donald R.; Blake, Nicola J.; Apel, Eric C.; Hornbrook, Rebecca S.; Flocke, Frank; Campos, Teresa; Diskin, Glenn

    2016-04-01

    We examine wet scavenging of soluble trace gases in storms observed during the Deep Convective Clouds and Chemistry (DC3) field campaign. We conduct high-resolution simulations with the Weather Research and Forecasting model with Chemistry (WRF-Chem) of a severe storm in Oklahoma. The model represents well the storm location, size, and structure as compared with Next Generation Weather Radar reflectivity, and simulated CO transport is consistent with aircraft observations. Scavenging efficiencies (SEs) between inflow and outflow of soluble species are calculated from aircraft measurements and model simulations. Using a simple wet scavenging scheme, we simulate the SE of each soluble species within the error bars of the observations. The simulated SEs of all species except nitric acid (HNO3) are highly sensitive to the values specified for the fractions retained in ice when cloud water freezes. To reproduce the observations, we must assume zero ice retention for formaldehyde (CH2O) and hydrogen peroxide (H2O2) and complete retention for methyl hydrogen peroxide (CH3OOH) and sulfur dioxide (SO2), likely to compensate for the lack of aqueous chemistry in the model. We then compare scavenging efficiencies among storms that formed in Alabama and northeast Colorado and the Oklahoma storm. Significant differences in SEs are seen among storms and species. More scavenging of HNO3 and less removal of CH3OOH are seen in storms with higher maximum flash rates, an indication of more graupel mass. Graupel is associated with mixed-phase scavenging and lightning production of nitrogen oxides (NOx), processes that may explain the observed differences in HNO3 and CH3OOH scavenging.

  19. Modeling, Simulation, and Flight Test for Automatic Flight Control of the Condor Hybrid-Electric Remote Piloted Aircraft

    Science.gov (United States)

    2012-03-01

    Aircraft Longitudinal Definitions (Nelson, 1998 p.123) ................................... 15 Table 4: Aircraft Lateral/Directional Derivatives...plane. Also known as the Roll angle. 15 Table 3: Aircraft Longitudinal Definitions (Nelson, 1998 p.123) Table 4...22 with tuning the longitudinal parameters arise when shifts in the center of gravity due to cargo loading change the aircraft longitudinal moment

  20. Correlation between subjective assessments of local thermal discomfort and thermal manikin measurements in a simulated aircraft cabin

    DEFF Research Database (Denmark)

    Zukowska, Daria; Strøm-Tejsen, Peter; Jama, Agnieszka

    2005-01-01

    participated, each being exposed to the same three temperature conditions during simulated 7-hour transatlantic flights. The assessments indicate that an air temperature increase in the middle of a 7-hour flight period followed by a decrease before landing might be preferred. A comparison be-tween manikin......The thermal environment in a 21-seat simulated section of an aircraft cabin installed in a climate chamber was investigated. Using two thermal manikins and fourteen heated cylin-ders to represent passengers, measurements were carried out at cabin temperatures of 20.6°C, 23.3°C and 26.1°C (69°F, 74...

  1. Reflective Responses Following a Role Play Simulation of Nurse Bullying

    Science.gov (United States)

    Ulrich, Deborah L.; Gillespie, Gordon Lee; Boesch, Maura C.; Bateman, Kyle M.; Grubb, Paula L.

    2017-01-01

    The affective domain of learning can be used with role play simulation to develop professional values in nursing students. A qualitative exploratory design was used for this study to evaluate role play simulation as an active learning strategy. The context for the role play was bullying in nursing practice. Three hundred thirty-three senior nursing students from five college campuses participated. Following the role play simulation students completed a reflection worksheet. The worksheet data were qualitatively coded into themes. Thematic findings were personal responses during the simulation, nonverbal communications exhibited during the simulation, actions taken by participants during the simulation, and the perceived impact of bullying. Role play simulation was a highly effective pedagogy requiring no technology, was free, and elicited learning at both the cognitive and affective domains of learning. PMID:28628071

  2. Experimental and Numerical Simulation of the Dynamic Frictional Contact between an Aircraft Tire Rubber and a Rough Surface

    Directory of Open Access Journals (Sweden)

    Iulian Rosu

    2016-08-01

    Full Text Available This paper presents a numerical simulation of an aircraft tire in contact with a rough surface using a variable friction coefficient dependent on temperature and contact pressure. A sliding facility was used in order to evaluate this dependence of the friction coefficient. The temperature diffusion throughout the tire cross-section was measured by means of thermocouples. Both frictional heating and temperature diffusion were compared to numerical two- and three- dimensional simulations. An adequate temperature prediction could be obtained. In future simulations, wear should be taken into account in order to have a more accurate simulation especially in the case of high pressures and slipping velocities. A 3D finite element model for a rolling tire at a velocity of 37.79 knots (19.44 m/s and in a cornering phase was investigated using a variable friction coefficient dependent on temperature and pressure. The numerical simulation tended to predict the temperature of the tire tread after a few seconds of rolling in skidding position, the temperature of the contact zone increases to 140 °C. Further investigations must be carried out in order to obtain the evolution of the temperature observed experimentally. The authors would like to point out that for confidentiality reasons, certain numerical data could not be revealed.

  3. Contribution to the modelling and simulation of aircraft structures impacting on water

    OpenAIRE

    Toso, Nathalie Renée Solange

    2009-01-01

    The impact on water of aeronautical structures is of concern as soon as an aircraft is designed to operate over sea. For the need of the ditching certification, it can be summarised that the structure should be able to land on water and float long enough to enable the passengers and crew members to evacuate. Until the middle of the 90's, compliance to the regulations was mainly shown by tests performed in a basin using a mock-up structure completed by relative simple theoretical evaluations o...

  4. Key considerations in infrared simulations of the missile-aircraft engagement

    CSIR Research Space (South Africa)

    Willers, MS

    2012-09-01

    Full Text Available of these details are investigated in Section 6. The tactical missile system used against aircraft includes several subsystems: airframe, flight control, fuze, propulsion, telemetry, data link, warhead and seeker.4 The seeker of an imaging IR missile provides...://proceedings.spiedigitallibrary.org/ on 12/19/2012 Terms of Use: http://spiedl.org/terms /7 dual mode detectors view a scene in two separate bands of the spectrum. The seeker compares the spectral distribution ratio of the various targets in the field of view to a predefined threshold. If a...

  5. 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.

  6. Aircraft microwave observations and simulations of deep convection from 18 to 183 GHz. I - Observations

    Science.gov (United States)

    Adler, Robert F.; Mack, Robert A.; Prasad, N.; Hakkarinen, Ida M.; Yeh, H.-Y. M.

    1990-01-01

    Aircraft passive microwave observations of deep atmospheric convection at frequencies between 18 and 183 GHz are presented in conjunction with visible and infrared satellite and aircraft observations and ground-based radar observations. Deep convective cores are indicated in the microwave data by negative brightness temperature, T/(B) deviations from the land background (270 K) to extreme T(B) values below 100 K at 37, 92, and 183 GHz and below 200 K at 18 GHz. These T(B) minima, due to scattering by ice held aloft by the intense updrafts, are well correlated with areas of high radar reflectivity. For this land background case, T(B) is inversely correlated with rain rate at all frequencies due to T(B)-ice-rain correlations. Mean Delta-T between vertically polarized and horizontally polarized radiance in precipitation areas is approximately 6 K at both 18 GHz and 37 GHz, indicating nonspherical precipitation-size ice particles with a preferred horizontal orientation. Convective cores not observed in the visible and infrared data are clearly defined in the microwave observations, and borders of convective rain areas are well defined using the high-frequency (90 GHz and greater) microwave observations.

  7. Rim Sim: A Role-Play Simulation

    Science.gov (United States)

    Barrett, Robert C.; Frew, Suzanne L.; Howell, David G.; Karl, Herman A.; Rudin, Emily B.

    2003-01-01

    Rim Sim is a 6-hour, eight-party negotiation that focuses on creating a framework for the long-term disaster-recovery efforts. It involves a range of players from five countries affected by two natural disasters: a typhoon about a year ago and an earthquake about 6 months ago. The players are members of an International Disaster Working Group (IDWG) that has been created by an international commission. The IDWG has been charged with drawing up a framework for managing two issues: the reconstruction of regionally significant infrastructure and the design of a mechanism for allocating funding to each country for reconstruction of local infrastructure and ongoing humanitarian needs. The first issue will involve making choices among five options (two harbor options, two airport options, and one rail-line option), each of which will have three levels at which to rebuild. The second issue will involve five starting-point options. Participants are encouraged to invent other options for both issues. The goal of Rim Sim is to raise questions about traditional approaches to disaster-preparedness planning and reconstruction efforts in an international setting, in this case the Pacific Rim. Players must confront the reverberating effects of disasters and the problems of using science and technical information in decisionmaking, and are introduced to a consensus-building approach emphasizing face-to-face dialog and multinational cooperation in dealing with humanitarian concerns, as well as long-term efforts to reconstruct local and regional infrastructure. The Rim Sim simulation raises four key points: ripple effects of disasters, role of science, multiparty negotiation, and building personal relationships.

  8. Small Aircraft Transportation System Simulation Analysis of the HVO and ERO Concepts

    Science.gov (United States)

    Millsaps, Gary D.; Yackovetsky, Robert E. (Technical Monitor)

    2003-01-01

    It is acknowledged that the aviation and aerospace industries are primary forces influencing the industrial development and economic well being of the United States and many countries around the world. For decades the US national air transportation system has been the model of success - safely and efficiently moving people, cargo, goods and services and generating countless benefits throughout the global community; however, the finite nature of the system and many of its components is becoming apparent. Without measurable increases in the capacity of the national air transportation system, delays and service delivery failures will eventually become intolerable. Although the recent economic slowdown has lowered immediate travel demands, that trend is reversing and cargo movement remains high. Research data indicates a conservative 2.5-3.0% annual increase in aircraft operations nationwide through 2017. Such growth will place additional strains upon a system already experiencing capacity constraints. The stakeholders of the system will continue to endure ever-increasing delays and abide lesser levels of service to many lower population density areas of the country unless more efficient uses of existing and new transportation resources are implemented. NASA s Small Aircraft Transportation System program (SATS) is one of several technologies under development that are aimed at using such resources more effectively. As part of this development effort, this report is the first in a series outlining the findings and recommendations resulting from a comprehensive program of multi-level analyses and system engineering efforts undertaken by NASA Langley Research Center s Systems Analysis Branch (SAB). These efforts are guided by a commitment to provide systems-level analysis support for the SATS program. Subsequent efforts will build upon this early work to produce additional analyses and benefits studies needed to provide the technical and economic basis for national

  9. Aircraft Noise Prediction

    OpenAIRE

    2014-01-01

    This contribution addresses the state-of-the-art in the field of aircraft noise prediction, simulation and minimisation. The point of view taken in this context is that of comprehensive models that couple the various aircraft systems with the acoustic sources, the propagation and the flight trajectories. After an exhaustive review of the present predictive technologies in the relevant fields (airframe, propulsion, propagation, aircraft operations, trajectory optimisation), the paper add...

  10. DASMAT-Delft University Aircraft Simulation Model and Analysis Tool: A Matlab/Simulink Environment for Flight Dynamics and Control Analysis

    NARCIS (Netherlands)

    Van der Linden, C.A.A.M.

    1998-01-01

    Computer Assisted Design (CAD) environments have become important devices for the design and evaluation of flight control systems. For general use, different aircraft and operational conditions should be easily implemented in such a CAD environment and it should be equipped with a set of simulation

  11. DASMAT-Delft University Aircraft Simulation Model and Analysis Tool: A Matlab/Simulink Environment for Flight Dynamics and Control Analysis

    NARCIS (Netherlands)

    Van der Linden, C.A.A.M.

    1998-01-01

    Computer Assisted Design (CAD) environments have become important devices for the design and evaluation of flight control systems. For general use, different aircraft and operational conditions should be easily implemented in such a CAD environment and it should be equipped with a set of simulation

  12. The role of simulation in intertemporal choices

    Directory of Open Access Journals (Sweden)

    Garret eO'Connell

    2015-03-01

    Full Text Available One route to understanding the thoughts and feelings of others is by mentally putting one’s self in their shoes and seeing the world from their perspective, called simulation. Simulation is potentially used not only for inferring how others feel, but also for predicting how we ourselves will feel in the future. For instance, one might judge the worth of a future reward by simulating how much it will eventually be enjoyed. In intertemporal choices between smaller immediate and larger delayed rewards, it is observed that as the length of delay increases, delayed larger rewards lose subjective value; a phenomenon known as temporal discounting. In this article, we develop a theoretical framework for the proposition that simulation mechanisms involved in empathising with others also underlie intertemporal choices. This framework yields a testable psychological account of temporal discounting based on simulation. Such an account, if experimentally validated, could have important implications for how simulation mechanisms are investigated, and makes predictions about special populations characterised by putative deficits in simulating others.

  13. Propulsion Powertrain Real-Time Simulation Using Hardware-in-the-Loop (HIL) for Aircraft Electric Propulsion System

    Science.gov (United States)

    Choi, Benjamin B.; Brown, Gerald V.

    2017-01-01

    It is essential to design a propulsion powertrain real-time simulator using the hardware-in-the-loop (HIL) system that emulates an electrified aircraft propulsion (EAP) systems power grid. This simulator would enable us to facilitate in-depth understanding of the system principles, to validate system model analysis and performance prediction, and to demonstrate the proof-of-concept of the EAP electrical system. This paper describes how subscale electrical machines with their controllers can mimic the power components in an EAP powertrain. In particular, three powertrain emulations are presented to mimic 1) a gas turbo-=shaft engine driving a generator, consisting of two permanent magnet (PM) motors with brushless motor drives, coupled by a shaft, 2) a motor driving a propulsive fan, and 3) a turbo-shaft engine driven fan (turbofan engine) operation. As a first step towards the demonstration, experimental dynamic characterization of the two motor drive systems, coupled by a mechanical shaft, were performed. The previously developed analytical motor models1 were then replaced with the experimental motor models to perform the real-time demonstration in the predefined flight path profiles. This technique can convert the plain motor system into a unique EAP power grid emulator that enables rapid analysis and real-time simulation performance using hardware-in-the-loop (HIL).

  14. The Role of Simulation in Clinical Information Systems Development

    DEFF Research Database (Denmark)

    Jensen, Sanne; Lyng, Karen Marie; Nøhr, Christian

    2012-01-01

    This paper describes the role of simulation involving end-users in Health Informatics. Simulation has long been established as a widely accepted method in clinical skills training. During the last decade simulation has also gained a place in the development and evaluation of clinical information...... systems. Simulation is especially well suited for the evaluation of human factors and organizational aspects in relation to application of information systems. In full-scale simulation tests it is possible to evaluate socio-technical interaction. A near to real life experience can be achieved by creating...... high fidelity environments. The paper discusses how simulation may be used during the lifecycle of clinical information systems, and the requirements on simulation fidelity in various situations. We recommend that simulation should get a more prominent role in the design and evaluation of clinical...

  15. High-Fidelity Multi-Rotor Unmanned Aircraft System Simulation Development for Trajectory Prediction Under Off-Nominal Flight Dynamics

    Science.gov (United States)

    Foster, John V.; Hartman, David C.

    2017-01-01

    The NASA Unmanned Aircraft System (UAS) Traffic Management (UTM) project is conducting research to enable civilian low-altitude airspace and UAS operations. A goal of this project is to develop probabilistic methods to quantify risk during failures and off nominal flight conditions. An important part of this effort is the reliable prediction of feasible trajectories during off-nominal events such as control failure, atmospheric upsets, or navigation anomalies that can cause large deviations from the intended flight path or extreme vehicle upsets beyond the normal flight envelope. Few examples of high-fidelity modeling and prediction of off-nominal behavior for small UAS (sUAS) vehicles exist, and modeling requirements for accurately predicting flight dynamics for out-of-envelope or failure conditions are essentially undefined. In addition, the broad range of sUAS aircraft configurations already being fielded presents a significant modeling challenge, as these vehicles are often very different from one another and are likely to possess dramatically different flight dynamics and resultant trajectories and may require different modeling approaches to capture off-nominal behavior. NASA has undertaken an extensive research effort to define sUAS flight dynamics modeling requirements and develop preliminary high fidelity six degree-of-freedom (6-DOF) simulations capable of more closely predicting off-nominal flight dynamics and trajectories. This research has included a literature review of existing sUAS modeling and simulation work as well as development of experimental testing methods to measure and model key components of propulsion, airframe and control characteristics. The ultimate objective of these efforts is to develop tools to support UTM risk analyses and for the real-time prediction of off-nominal trajectories for use in the UTM Risk Assessment Framework (URAF). This paper focuses on modeling and simulation efforts for a generic quad-rotor configuration typical

  16. Nonlinear Aerodynamics-Structure Time Simulation for HALE Aircraft Design/Analysis Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Time simulation of a nonlinear aerodynamics model (NA) developed at Virginia Tech coupled with a nonlinear structure model (NS) is proposed as a design/analysis...

  17. Confidence estimation in the application of simulation in the development of aircraft self-protection measures

    CSIR Research Space (South Africa)

    Willers, CJ

    2011-04-01

    Full Text Available and modelling, design synthesis, solution implementation and deployment. Results from the activities in this workflow are used to support the estimation of confidence in the simulation tools. The well known Qualification, Verification and Validation (QVV) model...

  18. Qualitative Evaluation of a Role Play Bullying Simulation.

    Science.gov (United States)

    Gillespie, Gordon L; Brown, Kathryn; Grubb, Paula; Shay, Amy; Montoya, Karen

    Bullying against nurses is becoming a pervasive problem. In this article, a role play simulation designed for undergraduate nursing students is described. In addition, the evaluation findings from a subsample of students who participated in a role play simulation addressing bullying behaviors are reported. Focus group sessions were completed with a subset of eight students who participated in the intervention. Sessions were audiorecorded, transcribed verbatim, and analyzed using Colaizzi's procedural steps for qualitative analysis. Themes derived from the data were "The Experience of Being Bullied", "Implementation of the Program", "Desired Outcome of the Program", and "Context of Bullying in the Nursing Profession". Role play simulation was an effective and active learning strategy to diffuse education on bullying in nursing practice. Bullying in nursing was identified as a problem worthy of incorporation into the undergraduate nursing curriculum. To further enhance the learning experience with role play simulation, adequate briefing instructions, opportunity to opt out of the role play, and comprehensive debriefing are essential.

  19. Occupant evaluation of 7-hour exposures in a simulated aircraft cabin - Part 1: Optimum balance between fresh air supply and humidity

    DEFF Research Database (Denmark)

    Strøm-Tejsen, Peter; Wyon, David Peter; Lagercrantz, Love Per

    2005-01-01

    low humidity. Experiments simulating 7-hour transatlantic flights were car-ried out at four outside air supply rates - 1.4, 3.3, 4.7 and 9.4 L/s per person (3, 7, 10 and 20 cfm/p) - yielding average humidity levels of 28%, 16%, 11% and 7% RH, respectively. Four groups of 16-18 subjects were exposed......Low humidity in the aircraft cabin environment has been identified as a possible cause of symptoms experienced during long flights. A mock-up of a 21-seat section of an aircraft cabin with realistic pollution sources was built inside a climate chamber, capable of providing fresh outside air at very...... to the four conditions. The subjects completed ques-tionnaires to provide subjective assessments of symptoms commonly experienced during flights. Increasing humidity to 28% RH by reducing outside air supply rate did not reduce the intensity of the symptoms typical of the aircraft cabin environment...

  20. Model-Based Control of a Nonlinear Aircraft Engine Simulation using an Optimal Tuner Kalman Filter Approach

    Science.gov (United States)

    Connolly, Joseph W.; Csank, Jeffrey Thomas; Chicatelli, Amy; Kilver, Jacob

    2013-01-01

    This paper covers the development of a model-based engine control (MBEC) methodology featuring a self tuning on-board model applied to an aircraft turbofan engine simulation. Here, the Commercial Modular Aero-Propulsion System Simulation 40,000 (CMAPSS40k) serves as the MBEC application engine. CMAPSS40k is capable of modeling realistic engine performance, allowing for a verification of the MBEC over a wide range of operating points. The on-board model is a piece-wise linear model derived from CMAPSS40k and updated using an optimal tuner Kalman Filter (OTKF) estimation routine, which enables the on-board model to self-tune to account for engine performance variations. The focus here is on developing a methodology for MBEC with direct control of estimated parameters of interest such as thrust and stall margins. Investigations using the MBEC to provide a stall margin limit for the controller protection logic are presented that could provide benefits over a simple acceleration schedule that is currently used in traditional engine control architectures.

  1. Role of computational efficiency in process simulation

    Directory of Open Access Journals (Sweden)

    Kurt Strand

    1989-07-01

    Full Text Available It is demonstrated how efficient numerical algorithms may be combined to yield a powerful environment for analysing and simulating dynamic systems. The importance of using efficient numerical algorithms is emphasized and demonstrated through examples from the petrochemical industry.

  2. Simulation analysis of impact tests of steel plate reinforced concrete and reinforced concrete slabs against aircraft impact and its validation with experimental results

    Energy Technology Data Exchange (ETDEWEB)

    Sadiq, Muhammad, E-mail: muhammad.sadiq@pnra.org [Center for Nuclear Safety (CNS), Pakistan Nuclear Regulatory Authority (PNRA), PO Box 1912, Islamabad (Pakistan); Xiu Yun, Zhu, E-mail: lyzhuxiuyun@163.com [Nuclear and Radiation Safety Center (NSC), Ministry of Environmental Protection (MEP), Beijing (China); Rong, Pan, E-mail: panrong@chinansc.cn [Nuclear and Radiation Safety Center (NSC), Ministry of Environmental Protection (MEP), Beijing (China)

    2014-07-01

    Highlights: • Simulation analysis is carried out with two constitutive concrete models. • Winfrith model can better simulate nonlinear response of concrete than CSCM model. • Performance of steel plate concrete is better than reinforced concrete. • Thickness of safety related structures can be reduced by adopting steel plates. • Analysis results, mainly concrete material models should be validated. - Abstract: The steel plate reinforced concrete and reinforced concrete structures are used in nuclear power plants for protection against impact of an aircraft. In order to compare the impact resistance performance of steel plate reinforced concrete and reinforced concrete slabs panels, simulation analysis of 1/7.5 scale model impact tests is carried out by using finite element code ANSYS/LS-DYNA. The damage modes of all finite element models, velocity time history curves of the aircraft engine and damage to aircraft model are compared with the impact test results of steel plate reinforced concrete and reinforced concrete slab panels. The results indicate that finite element simulation results correlate well with the experimental results especially for constitutive winfrith concrete model. Also, the impact resistance performance of steel plate reinforced concrete slab panels is better than reinforced concrete slab panels, particularly the rear face steel plate is very effective in preventing the perforation and scabbing of concrete than conventional reinforced concrete structures. In this way, the thickness of steel plate reinforced concrete structures can be reduced in important structures like nuclear power plants against impact of aircraft. It also demonstrates the methodology to validate the analysis procedure with experimental and analytical studies. It may be effectively employed to predict the precise response of safety related structures against aircraft impact.

  3. Unmanned Aircraft Systems Detect and Avoid System: End-to-End Verification and Validation Simulation Study of Minimum Operations Performance Standards for Integrating Unmanned Aircraft into the National Airspace System

    Science.gov (United States)

    Ghatas, Rania W.; Jack, Devin P.; Tsakpinis, Dimitrios; Sturdy, James L.; Vincent, Michael J.; Hoffler, Keith D.; Myer, Robert R.; DeHaven, Anna M.

    2017-01-01

    As Unmanned Aircraft Systems (UAS) make their way to mainstream aviation operations within the National Airspace System (NAS), research efforts are underway to develop a safe and effective environment for their integration into the NAS. Detect and Avoid (DAA) systems are required to account for the lack of "eyes in the sky" due to having no human on-board the aircraft. The technique, results, and lessons learned from a detailed End-to-End Verification and Validation (E2-V2) simulation study of a DAA system representative of RTCA SC-228's proposed Phase I DAA Minimum Operational Performance Standards (MOPS), based on specific test vectors and encounter cases, will be presented in this paper.

  4. Propulsion controlled aircraft research

    Science.gov (United States)

    Fullerton, C. Gordon

    1993-01-01

    The NASA Dryden Flight Research Facility has been conducting flight, ground simulator, and analytical studies to investigate the use of thrust modulation on multi-engine aircraft for emergency flight control. Two general methods of engine only control have been studied; manual manipulation of the throttles by the pilot, and augmented control where a computer commands thrust levels in response to pilot attitude inputs and aircraft motion feedbacks. This latter method is referred to as the Propulsion Controlled Aircraft (PCA) System. A wide variety of aircraft have been investigated. Simulation studies have included the B720, F-15, B727, B747 and MD-11. A look at manual control has been done in actual flight on the F15, T-38, B747, Lear 25, T-39, MD-11 and PA-30 Aircraft. The only inflight trial of the augmented (PCA) concept has been on an F15, the results of which will be presented below.

  5. 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...

  6. 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...

  7. Multiscale macromolecular simulation: role of evolving ensembles.

    Science.gov (United States)

    Singharoy, A; Joshi, H; Ortoleva, P J

    2012-10-22

    Multiscale analysis provides an algorithm for the efficient simulation of macromolecular assemblies. This algorithm involves the coevolution of a quasiequilibrium probability density of atomic configurations and the Langevin dynamics of spatial coarse-grained variables denoted order parameters (OPs) characterizing nanoscale system features. In practice, implementation of the probability density involves the generation of constant OP ensembles of atomic configurations. Such ensembles are used to construct thermal forces and diffusion factors that mediate the stochastic OP dynamics. Generation of all-atom ensembles at every Langevin time step is computationally expensive. Here, multiscale computation for macromolecular systems is made more efficient by a method that self-consistently folds in ensembles of all-atom configurations constructed in an earlier step, history, of the Langevin evolution. This procedure accounts for the temporal evolution of these ensembles, accurately providing thermal forces and diffusions. It is shown that efficiency and accuracy of the OP-based simulations is increased via the integration of this historical information. Accuracy improves with the square root of the number of historical timesteps included in the calculation. As a result, CPU usage can be decreased by a factor of 3-8 without loss of accuracy. The algorithm is implemented into our existing force-field based multiscale simulation platform and demonstrated via the structural dynamics of viral capsomers.

  8. A High-Fidelity Simulation of a Generic Commercial Aircraft Engine and Controller

    Science.gov (United States)

    May, Ryan D.; Csank, Jeffrey; Lavelle, Thomas M.; Litt, Jonathan S.; Guo, Ten-Huei

    2010-01-01

    A new high-fidelity simulation of a generic 40,000 lb thrust class commercial turbofan engine with a representative controller, known as CMAPSS40k, has been developed. Based on dynamic flight test data of a highly instrumented engine and previous engine simulations developed at NASA Glenn Research Center, this non-proprietary simulation was created especially for use in the development of new engine control strategies. C-MAPSS40k is a highly detailed, component-level engine model written in MATLAB/Simulink (The MathWorks, Inc.). Because the model is built in Simulink, users have the ability to use any of the MATLAB tools for analysis and control system design. The engine components are modeled in C-code, which is then compiled to allow faster-than-real-time execution. The engine controller is based on common industry architecture and techniques to produce realistic closed-loop transient responses while ensuring that no safety or operability limits are violated. A significant feature not found in other non-proprietary models is the inclusion of transient stall margin debits. These debits provide an accurate accounting of the compressor surge margin, which is critical in the design of an engine controller. This paper discusses the development, characteristics, and capabilities of the C-MAPSS40k simulation

  9. UAS in the NAS Air Traffic Controller Acceptability Study-1: The Effects of Horizontal Miss Distances on Simulated UAS and Manned Aircraft Encounters

    Science.gov (United States)

    Ghatas, Rania W.; Comstock, James R., Jr.; Consiglio, Maria C.; Chamberlain, James P.; Hoffler, Keith D.

    2015-01-01

    This study examined air traffic controller acceptability ratings based on the effects of differing horizontal miss distances (HMDs) for encounters between UAS and manned aircraft. In a simulation of the Dallas/Fort Worth (DFW) East-side airspace, the CAS-1 experiment at NASA Langley Research Center enlisted fourteen recently retired DFW air traffic controllers to rate well-clear volumes based on differing HMDs that ranged from 0.5 NM to 3.0 NM. The controllers were tasked with rating these HMDs from "too small" to "too excessive" on a defined, 1-5, scale and whether these distances caused any disruptions to the controller and/or to the surrounding traffic flow. Results of the study indicated a clear favoring towards a particular HMD range. Controller workload was also measured. Data from this experiment and subsequent experiments will play a crucial role in the FAA's establishment of rules, regulations, and procedures to safely and efficiently integrate UAS into the NAS.

  10. 飞机座舱内空气品质计算%Numerical Simulation of Cabin Air Quality in Aircraft

    Institute of Scientific and Technical Information of China (English)

    刘静悦; 张大林; 纪兵兵

    2011-01-01

    为改善飞机座舱的空气分配系统,在某型飞机的一段客舱物理模型里,设计了天花板送风与行李架侧壁送风(可考虑或不考虑个人通风口送风)两种主要供气方案.使用雷诺平均Navier-Stokes方程下的k-ε湍流模型和增强壁面函数法来模拟舱内湍流流场,并分别计算空气的速度场和温度场分布,以及CO2浓度分布情况.通过对参数的分析比较,提出天花板送风方案配合个人通风口送风的使用可以提供较好的舱内空气品质,计算结果为座舱环控系统的优化设计提供一定的理论依据.%To improve the air distribution system for aircraft cabins,this paper uses numerical simulation under investigation. A detailed CFD model of a small section is built in the passenger cabin of an aircraft and a Reynolds-averaged Navier-Stokes (RANS) simulation with the k-ε equations is performed to adjust turbulence. The CFD program is used to calculate the distribution of the air velocity,air temperature,and CO2 concentration in the cabin with the ceiling air supply system and luggage air displacement system (the personalized air distribution systems can be considered or not), respectively. By comparing the air and contaminant distributions in the cabin,this study comes to the conclusion that the air quality is better by the ceiling air supply with the personalized air distribution system.

  11. 舰载机蒸汽弹射动力学仿真分析%Dynamics Simulation of Carrier-based Aircraft Steam Catapult

    Institute of Scientific and Technical Information of China (English)

    张雷; 冯蕴雯; 薛小锋; 冯元生

    2012-01-01

    This article illustrates the need for a steam catapult device applications. Proposed the dynamics simulation model of carrier- based aircraft steam catapult on the basis of comprehensive consideration of the thermodynamic model, the traction release device mathematical model , aircraft kinetics model and landing gear jump and other factors. Based on C - 13 catapult and a certain type of aircraft,a simulation analysis is presented. The results,which are compared with test data,provide a useful reference for the design of carrier- based aircraft steam catapult system and experimental verification.%阐明了蒸汽弹射装置应用的必要性.在综合考虑热力学模型、牵引释放装置数学模型、舰载机动力学模型以及起落架突伸等因素的基础上,提出了舰载机蒸汽弹射动力学仿真分析模型.以C-13型弹射器和某型飞机为例进行了仿真分析,并与相关实验数据进行对比分析,其分析结果可为舰栽机蒸汽弹射系统设计以及试验验证提供有益参考.

  12. Reference energy-altitude descent guidance: Simulator evaluation. [aircraft descent and fuel conservation

    Science.gov (United States)

    Abbot, K. H.; Knox, C. E.

    1985-01-01

    Descent guidance was developed to provide a pilot with information to ake a fuel-conservative descent and cross a designated geographical waypoint at a preselected altitude and airspeed. The guidance was designed to reduce fuel usage during the descent and reduce the mental work load associated with planning a fuel-conservative descent. A piloted simulation was conducted to evaluate the operational use of this guidance concept. The results of the simulation tests show that the use of the guidance reduced fuel consumption and mental work load during the descent. Use of the guidance also decreased the airspeed error, but had no effect on the altitude error when the designated waypoint was crossed. Physical work load increased with the use of the guidance, but remained well within acceptable levels. The pilots found the guidance easy to use as presented and reported that it would be useful in an operational environment.

  13. A Study of the Characteristics of Human-Pilot Control Response to Simulated Aircraft Lateral Motions

    Science.gov (United States)

    Cheatham, Donald C

    1954-01-01

    Report presents the results of studies made in an attempt to provide information on the control operations of the human pilot. These studies included an investigation of the ability of pilots to control simulated unstable yawing oscillations, a study of the basic characteristics of human-pilot control response, and a study to determine whether and to what extent pilot control response can be represented in an analytical form.

  14. Nonlinear Gust Response Analysis of Free Flexible Aircraft

    Directory of Open Access Journals (Sweden)

    Chen Shilu

    2013-01-01

    Full Text Available Gust response analysis plays a very important role in large aircraft design. This paper presents a methodology for calculating the flight dynamic characteristics and gust response of free flexible aircraft. A multidisciplinary coupled numerical tool is developed to simulate detailed aircraft models undergoing arbitrary free flight motion in the time domain, by Computational Fluid Dynamics (CFD, Computational Structure Dynamics (CSD and Computational Flight Mechanics (CFM coupling. To achieve this objective, a structured, time-accurate flow-solver is coupled with a computational module solving the flight mechanics equations of motion and a structural mechanics code determining the structural deformations. A novel method to determine the trim state of flexible aircraft is also stated. First, the field velocity approach is validated, after the trim state is attained, gust responses for the one-minus-cosine gust profile are analyzed for the longitudinal motion of a slender-wing aircraft configuration with and without the consideration of structural deformation.

  15. High-fidelity simulation among bachelor students in simulation groups and use of different roles.

    Science.gov (United States)

    Thidemann, Inger-Johanne; Söderhamn, Olle

    2013-12-01

    Cost limitations might challenge the use of high-fidelity simulation as a teaching-learning method. This article presents the results of a Norwegian project including two simulation studies in which simulation teaching and learning were studied among students in the second year of a three-year bachelor nursing programme. The students were organised into small simulation groups with different roles; nurse, physician, family member and observer. Based on experiences in different roles, the students evaluated the simulation design characteristics and educational practices used in the simulation. In addition, three simulation outcomes were measured; knowledge (learning), Student Satisfaction and Self-confidence in Learning. The simulation was evaluated to be a valuable teaching-learning method to develop professional understanding and insight independent of roles. Overall, the students rated the Student Satisfaction and Self-confidence in Learning as high. Knowledge about the specific patient focus increased after the simulation activity. Students can develop practical, communication and collaboration skills, through experiencing the nurse's role. Assuming the observer role, students have the potential for vicarious learning, which could increase the learning value. Both methods of learning (practical experience or vicarious learning) may bridge the gap between theory and practice and contribute to the development of skills in reflective and critical thinking.

  16. Researcher's guide to the NASA Ames Flight Simulator for Advanced Aircraft (FSAA)

    Science.gov (United States)

    Sinacori, J. B.; Stapleford, R. L.; Jewell, W. F.; Lehman, J. M.

    1977-01-01

    Performance, limitations, supporting software, and current checkout and operating procedures are presented for the flight simulator, in terms useful to the researcher who intends to use it. Suggestions to help the researcher prepare the experimental plan are also given. The FSAA's central computer, cockpit, and visual and motion systems are addressed individually but their interaction is considered as well. Data required, available options, user responsibilities, and occupancy procedures are given in a form that facilitates the initial communication required with the NASA operations' group.

  17. Propulsion Electric Grid Simulator (PEGS) for Future Turboelectric Distributed Propulsion Aircraft

    Science.gov (United States)

    Choi, Benjamin B.; Morrison, Carlos; Dever, Timothy; Brown, Gerald V.

    2014-01-01

    NASA Glenn Research Center, in collaboration with the aerospace industry and academia, has begun the development of technology for a future hybrid-wing body electric airplane with a turboelectric distributed propulsion (TeDP) system. It is essential to design a subscale system to emulate the TeDP power grid, which would enable rapid analysis and demonstration of the proof-of-concept of the TeDP electrical system. This paper describes how small electrical machines with their controllers can emulate all the components in a TeDP power train. The whole system model in Matlab/Simulink was first developed and tested in simulation, and the simulation results showed that system dynamic characteristics could be implemented by using the closed-loop control of the electric motor drive systems. Then we designed a subscale experimental system to emulate the entire power system from the turbine engine to the propulsive fans. Firstly, we built a system to emulate a gas turbine engine driving a generator, consisting of two permanent magnet (PM) motors with brushless motor drives, coupled by a shaft. We programmed the first motor and its drive to mimic the speed-torque characteristic of the gas turbine engine, while the second motor and drive act as a generator and produce a torque load on the first motor. Secondly, we built another system of two PM motors and drives to emulate a motor driving a propulsive fan. We programmed the first motor and drive to emulate a wound-rotor synchronous motor. The propulsive fan was emulated by implementing fan maps and flight conditions into the fourth motor and drive, which produce a torque load on the driving motor. The stator of each PM motor is designed to travel axially to change the coupling between rotor and stator. This feature allows the PM motor to more closely emulate a wound-rotor synchronous machine. These techniques can convert the plain motor system into a unique TeDP power grid emulator that enables real-time simulation performance

  18. Numerical simulation of flows around deformed aircraft model in a wind tunnel

    Science.gov (United States)

    Lysenkov, A. V.; Bosnyakov, S. M.; Glazkov, S. A.; Gorbushin, A. R.; Kuzmina, S. I.; Kursakov, I. A.; Matyash, S. V.; Ishmuratov, F. Z.

    2016-10-01

    To obtain accurate data of calculation method error requires detailed simulation of the experiment in wind tunnel with keeping all features of the model, installation and gas flow. Two examples of such detailed data comparison are described in this paper. The experimental characteristics of NASA CRM model obtained in the ETW wind tunnel (Cologne, Germany), and CFD characteristics of this model obtained with the use of EWT-TsAGI application package are compared. Following comparison is carried out for an airplane model in the T-128 wind tunnel (TsAGI, Russia). It is seen that deformation influence on integral characteristics grows with increasing Re number and, accordingly, the dynamic pressure. CFD methods application for problems of experimental research in the wind tunnel allows to separate viscosity and elasticity effects.

  19. Far-field noise and internal modes from a ducted propeller at simulated aircraft takeoff conditions

    Science.gov (United States)

    Woodward, Richard P.; Bock, Lawrence A.; Heidelberg, Laurence J.; Hall, David G.

    1992-01-01

    The ducted propeller offers structural and acoustic benefits typical of conventional turbofan engines while retaining much of the aeroacoustic benefits of the unducted propeller. A model Advanced Ducted Propeller (ADP) was tested in the NASA Lewis Low-Speed Anechoic Wind Tunnel at a simulated takeoff velocity of Mach 0.2. The ADP model was designed and manufactured by the Pratt and Whitney Division of United Technologies. The 16-blade rotor ADP was tested with 22- and 40-vane stators to achieve cut-on and cut-off criterion with respect to propagation of the fundamental rotor-stator interaction tone. Additional test parameters included three inlet lengths, three nozzle sizes, two spinner configurations, and two rotor rub strip configurations. The model was tested over a range of rotor blade setting angles and propeller axis angles-of-attack. Acoustic data were taken with a sideline translating microphone probe and with a unique inlet microphone probe which identified inlet rotating acoustic modes. The beneficial acoustic effects of cut-off were clearly demonstrated. A 5 dB fundamental tone reduction was associated with the long inlet and 40-vane sector, which may relate to inlet duct geometry. The fundamental tone level was essentially unaffected by propeller axis angle-of-attack at rotor speeds of at least 96 percent design.

  20. NUMERICAL SIMULATION OF CAVITY FLOW AND FLOW OVER AIRCRAFT COMPARTMENT USING SEMI-EMPIRICAL TURBULENCE MODELS

    Directory of Open Access Journals (Sweden)

    2016-01-01

    Full Text Available The article is devoted to the validation and application of CFD code for turbulent flows. Two-dimensional un- steady flows in the cavities and compartments and three-dimensional flow in the compartment of complex geometry have been considered. Two turbulence parameter oriented models are used.Numerical simulation of unsteady transonic flow (Mоо=0.74 in a narrow channel with a cavity inside has been conducted. The dependence of the static pressure on time at fixed points in space has been obtained. The fast Fourier trans- form has been applied for processing data of static pressure. The difference of 6-10% between the numerical and experi-mental data has been obtained.The computations of unsteady transonic cavity flow with Mach number Mоо=0.85 have been performed. Low fre- quency oscillations of the static pressure in several fixed points in space have been obtained. Power spectrum of oscilla- tions at the center of the cavity is compared with experimental data and Rossiter modes. An acceptable agreement between experimental and computed data has been achieved. The influence of geometrical factors on the frequency characteristics of the flow has been investigated. For this purpose two round flaps have been added to the cavity. The most low-frequency oscillation modes changed by the presence of the flaps. The first mode was gone, the second mode amplitude decreased and the third mode amplitude significantly decreased. The changes in height of protruding part of the geometry to the external flow have led to changes in pressure pulsation amplitude without changing the frequency. The spectral functions obtained while using the two considered models of turbulence have been compared for this case. It is found that the frequency values are only slightly different; the main difference is present at the amplitude of pulsations.The effect of deflection of flat flap on the non-stationary subsonic flow parameters in a cylindrical body with an inner

  1. Large-eddy simulation of a turbulent jet and a vortex sheet interaction: particle formation and evolution in the near field of an aircraft wake

    Directory of Open Access Journals (Sweden)

    Roberto Paoli

    2008-04-01

    Full Text Available Aircraft are prolific sources of particles (soot, liquid aerosols and contrails that can impact cloudiness and affect the Earth's radiative budget balance. In order to study the formation and evolution of these particles, a numerical approach has been developed combining large-eddy simulation (LES and a detailed microphysical model. Generally very detailed microphysical models are run along a single average trajectory, without any temperature fluctuation. However, this approach may lead to significant differences in particle properties and particle size distribution as it oversimplifies dynamical and mixing processes compared to multidimensional descriptions of aircraft wakes. This may affect the initialisation of meso-scale models, such as, for example, the formation of cloud condensation nuclei from persistent contrails, and heterogeneous chemical reactions. In this paper, we present the results of detailed microphysical processes calculations applied to a large number of fluid parcels trajectories, generated by a LES two-phase flow solver.

  2. Numerical Simulation of Flow Control over a Certain Aircraft with Gurney Flaps%Gurney襟翼对某型客机流动控制数值模拟

    Institute of Scientific and Technical Information of China (English)

    刘沛清; 杨硕

    2012-01-01

    为改善某型客机的起降性能,通过在机翼尾缘加装Gurney襟翼,对流场进行了数值模拟.对该客机机翼的控制翼型安装不同高度的Gurney襟翼进行数值模拟,结果表明安装Gurney襟翼可以提高多段翼型的升力系数和阻力系数,但会增强尾迹流动的不稳定性.将不同高度的Gurney襟翼应用于该客机的简化模型,机翼的大部分区域符合二维翼型研究得出的流动控制规律;在机翼外侧区域,Gurney襟翼使机翼附近流场中的翼尖涡发生了一定的变化.数值模拟的结果还表明,Gunney襟翼可以提高客机的升力系数,而且不会给飞机流场带来明显的改变.%This investigation is conducted to use Gurney flaps to improve the performance of an aircraft during taking off and landing. Numerical simulation method is used in the flow control study for a certain type of aircraft in the landing mode with Gurney flaps installed on the wing's trailing edge. The aircraft's main airfoil and the airfoils with Gurney flaps of different heights are simulated. The result indicates that the Gurney flap could improve the lift coefficient and drag coefficient of the multi-element airfoil, but it also enhances the flow instability. A simplified model of the aircraft and the models with Gurney flaps of different heights are simulated. In most of the wing region, the models with Gurney flaps show a flow pattern that accorded with the two-dimensional airfoil models with Gurney flaps, but in the outer region of the wing, Gurney flaps cause the tip vortex near the wing flow field to exert a greater impact. Numerical results show that Gurney flaps efficiently improve lift coefficient of the aircraft without significant changes to the flow field.

  3. 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. .

  4. Predicting Visibility of Aircraft

    Science.gov (United States)

    Watson, Andrew; Ramirez, Cesar V.; Salud, Ellen

    2009-01-01

    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. PMID:19462007

  5. An integrated approach for modelling of aircraft maintenance processes

    Directory of Open Access Journals (Sweden)

    D. Yu. Kiselev

    2015-01-01

    Full Text Available The paper deals with modeling of the processes of maintenance and repair of aircraft. The role of information in im-proving the effectiveness of maintenance systems is described. The methodology for functional modelling of maintenance processes is given. A simulation model is used for modelling possible changes.

  6. 某新型飞机维修模拟训练系统%Maintenance Simulation System of a New Type Aircraft

    Institute of Scientific and Technical Information of China (English)

    张伟; 库丽媛

    2011-01-01

    介绍了某新型飞机维修模拟训练系统的设计思路以及系统组成和特点,并结合系统的实现讨论了模拟仿真技术应用于装备维修的现实意义.实践证明,应用该系统开展飞机维修模拟训练解决了部队由于维修保障训练设备缺乏,机务人员难以进行全专业综合保障维修训练的难题,大大缩短了新机维修保障训练周期,节约了大量的装备维修保障经费.%The design concept of a new type aircraft maintenance simulation system is introduced The components, features and value of the simulation system are also described Practice shows that application of the simulation system can meet the requirements of aircraft maintenance training, shorten training cycle and save training funds.

  7. Dynamic Modeling and Simulation of Trans-media Aircraft System%两栖UAV动力学建模与仿真

    Institute of Scientific and Technical Information of China (English)

    裴譞; 张宇文; 袁绪龙; 张博

    2011-01-01

    The trans-media aircraft is the new concept amphibious aircraft moving between gas and water, which has been affect by aerodynamic force and the hydrodynamic force, and kinetics of it are different from the normal aircraft and planning boat. Based on the aerodynamic and the theory of planning, the dynamic model of the slide jump ballistics of the trans-media was developed. The simulation example had been given, and the process and characteristic of trans-media aircraft slide jump ballistics had been analyzed especially. It gives theoretical foundation and computation method for the conceptual design of trans-media system, planning shape design optimization and ballistics design.%两栖UAV是介于空气与水之间运动的新概念飞行器,由于同时受到空气动力,水动力的作用,动力学特征较巡航飞行器和水面滑行艇均有很大差别.基于空气动力学和二元平面滑行理论.建立了两栖UAV的飞行动力学模型和滑跳动力学模型,同时给出了仿真算例,并对两栖UAV的滑跳过程进行了弹道仿真研究.建模可以为两栖UAV的方案总体设计,滑水外形优化和弹道方案设计提供理论依据和计算方法.

  8. Aircraft Carriers

    DEFF Research Database (Denmark)

    Nødskov, Kim; Kværnø, Ole

    There are many indications that China is actively researching the design of an aircraft carrier. It is unknown whether China will initiate the actual acquisition of a carrier, but the indications that are available of their research into aircraft carriers and carrier-capable aircraft, as well...... 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...... of its foreign trade, as well as its oil imports, upon which the country is totally dependent. China therefore has good reasons for acquiring an aircraft carrier to enable it to protect its national interests. An aircraft carrier would also be a prominent symbol of China’s future status as a great power...

  9. Wet scavenging of soluble gases in DC3 deep convective storms using WRF-Chem simulations and aircraft observations: DEEP CONVECTIVE WET SCAVENGING OF GASES

    Energy Technology Data Exchange (ETDEWEB)

    Bela, Megan M. [Department of Atmospheric and Oceanic Sciences, University of Colorado Boulder, Boulder Colorado USA; Laboratory for Atmospheric and Space Physics, University of Colorado Boulder, Boulder Colorado USA; Barth, Mary C. [National Center for Atmospheric Research, Boulder Colorado USA; Toon, Owen B. [Department of Atmospheric and Oceanic Sciences, University of Colorado Boulder, Boulder Colorado USA; Laboratory for Atmospheric and Space Physics, University of Colorado Boulder, Boulder Colorado USA; Fried, Alan [Institute of Arctic and Alpine Research, University of Colorado Boulder, Boulder Colorado USA; Homeyer, Cameron R. [School of Meteorology, University of Oklahoma, Norman Oklahoma USA; Morrison, Hugh [National Center for Atmospheric Research, Boulder Colorado USA; Cummings, Kristin A. [Department of Atmospheric and Oceanic Science, University of Maryland, College Park Maryland USA; Li, Yunyao [Department of Atmospheric and Oceanic Science, University of Maryland, College Park Maryland USA; Pickering, Kenneth E. [Department of Atmospheric and Oceanic Science, University of Maryland, College Park Maryland USA; National Aeronautics and Space Administration/Goddard Space Flight Center, Greenbelt Maryland USA; Allen, Dale J. [Department of Atmospheric and Oceanic Science, University of Maryland, College Park Maryland USA; Yang, Qing [Pacific Northwest National Laboratory, Richland Washington USA; Wennberg, Paul O. [Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena California USA; Division of Engineering and Applied Science, California Institute of Technology, Pasadena California USA; Crounse, John D. [Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena California USA; St. Clair, Jason M. [National Aeronautics and Space Administration/Goddard Space Flight Center, Greenbelt Maryland USA; Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena California USA; Joint Center for Earth Systems Technology, University of Maryland, Baltimore County, Baltimore Maryland USA; Teng, Alex P. [Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena California USA; O' Sullivan, Daniel [U.S. Naval Academy, Annapolis Maryland USA; Huey, L. Gregory [School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta Georgia USA; Chen, Dexian [School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta Georgia USA; Liu, Xiaoxi [School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta Georgia USA; Blake, Donald R. [Department of Chemistry, University of California, Irvine California USA; Blake, Nicola J. [Department of Chemistry, University of California, Irvine California USA; Apel, Eric C. [National Center for Atmospheric Research, Boulder Colorado USA; Hornbrook, Rebecca S. [National Center for Atmospheric Research, Boulder Colorado USA; Flocke, Frank [National Center for Atmospheric Research, Boulder Colorado USA; Campos, Teresa [National Center for Atmospheric Research, Boulder Colorado USA; Diskin, Glenn [NASA Langley Research Center, Hampton Virginia USA

    2016-04-21

    We examine wet scavenging of soluble trace gases in storms observed during the Deep Convective Clouds and Chemistry (DC3) field campaign. We conduct high-resolution simulations with the Weather Research and Forecasting model with Chemistry (WRF-Chem) of a severe storm in Oklahoma. The model represents well the storm location, size, and structure as compared with Next Generation Weather Radar reflectivity, and simulated CO transport is consistent with aircraft observations. Scavenging efficiencies (SEs) between inflow and outflow of soluble species are calculated from aircraft measurements and model simulations. Using a simple wet scavenging scheme, we simulate the SE of each soluble species within the error bars of the observations. The simulated SEs of all species except nitric acid (HNO3) are highly sensitive to the values specified for the fractions retained in ice when cloud water freezes. To reproduce the observations, we must assume zero ice retention for formaldehyde (CH2O) and hydrogen peroxide (H2O2) and complete retention for methyl hydrogen peroxide (CH3OOH) and sulfur dioxide (SO2), likely to compensate for the lack of aqueous chemistry in the model. We then compare scavenging efficiencies among storms that formed in Alabama and northeast Colorado and the Oklahoma storm. Significant differences in SEs are seen among storms and species. More scavenging of HNO3 and less removal of CH3OOH are seen in storms with higher maximum flash rates, an indication of more graupel mass. Graupel is associated with mixed-phase scavenging and lightning production of nitrogen oxides (NOx ), processes that may explain the observed differences in HNO3 and CH3OOH scavenging.

  10. Interaction of Aircraft Wakes From Laterally Spaced Aircraft

    Science.gov (United States)

    Proctor, Fred H.

    2009-01-01

    Large Eddy Simulations are used to examine wake interactions from aircraft on closely spaced parallel paths. Two sets of experiments are conducted, with the first set examining wake interactions out of ground effect (OGE) and the second set for in ground effect (IGE). The initial wake field for each aircraft represents a rolled-up wake vortex pair generated by a B-747. Parametric sets include wake interactions from aircraft pairs with lateral separations of 400, 500, 600, and 750 ft. The simulation of a wake from a single aircraft is used as baseline. The study shows that wake vortices from either a pair or a formation of B-747 s that fly with very close lateral spacing, last longer than those from an isolated B-747. For OGE, the inner vortices between the pair of aircraft, ascend, link and quickly dissipate, leaving the outer vortices to decay and descend slowly. For the IGE scenario, the inner vortices ascend and last longer, while the outer vortices decay from ground interaction at a rate similar to that expected from an isolated aircraft. Both OGE and IGE scenarios produce longer-lasting wakes for aircraft with separations less than 600 ft. The results are significant because concepts to increase airport capacity have been proposed that assume either aircraft formations and/or aircraft pairs landing on very closely spaced runways.

  11. Modeling and Simulation of Aircraft Three-stage Synchronous Generator%飞机三级发电机的建模与仿真

    Institute of Scientific and Technical Information of China (English)

    王薛洲; 张晓斌; 潘荻

    2013-01-01

    Three - stage synchronous generator with brushless exciter is a common structure in aircraft AC power system, which contains vice exciter, excitation machine and the main generator. In order to simulate the aircraft power system, the structure of three - stage generator was introduced and its mathematical model in dqO coordinate system was built by using MAST Language based on Saber platform. The dynamic results of the synchronous generator working with GCU and electrical loads were obtained after simulating. The results show the different responses of three - stage generator with respect to different loads, which proves the validity of the model. This model provides a more effective tool to design the aircraft power system.%研究飞机电源系统供电优化问题,飞机交流发电系统多采用三级式无刷交流同步发电机,由永磁发电机、交流励磁机和主发电机组成.为了仿真飞机三级发电机,在介绍三级同步发电机结构的基础上,通过派克变换在dq0坐标系下,建立三级发电机的动态数学模型,在Saber软件平台下使用MAST语言编写同步发电机模型,结合调压器及电气负载得到三级发电机的部分动态仿真结果,仿真结果能够很好地显示三级发电机对不同负载的响应,证明了模型的正确性,为飞机电源系统的设计提供了一个有效的工具.

  12. Guidance Systems of Fighter Aircraft

    Directory of Open Access Journals (Sweden)

    K.N. Rajanikanth

    2005-07-01

    Full Text Available Mission performance of a fighter aircraft is crucial for survival and strike capabilities in todays' aerial warfare scenario. The guidance functions of such an aircraft play a vital role inmeeting the requirements and accomplishing the mission success. This paper presents the requirements of precision guidance for various missions of a fighter aircraft. The concept ofguidance system as a pilot-in-loop system is pivotal in understanding and designing such a system. Methodologies of designing such a system are described.

  13. Guidance Systems of Fighter Aircraft

    OpenAIRE

    K.N. Rajanikanth; Rao, R S; P. S. Subramanyam; Ajai Vohra

    2005-01-01

    Mission performance of a fighter aircraft is crucial for survival and strike capabilities in todays' aerial warfare scenario. The guidance functions of such an aircraft play a vital role inmeeting the requirements and accomplishing the mission success. This paper presents the requirements of precision guidance for various missions of a fighter aircraft. The concept ofguidance system as a pilot-in-loop system is pivotal in understanding and designing such a system. Methodologies of designing s...

  14. Aircraft Design

    Science.gov (United States)

    Bowers, Albion H. (Inventor); Uden, Edward (Inventor)

    2016-01-01

    The present invention is an aircraft wing design that creates a bell shaped span load, which results in a negative induced drag (induced thrust) on the outer portion of the wing; such a design obviates the need for rudder control of an aircraft.

  15. Expressions of Critical Thinking in Role-Playing Simulations: Comparisons across Roles

    Science.gov (United States)

    Ertmer, Peggy A.; Strobel, Johannes; Cheng, Xi; Chen, Xiaojun; Kim, Hannah; Olesova, Larissa; Sadaf, Ayesha; Tomory, Annette

    2010-01-01

    The development of critical thinking is crucial in professional education to augment the capabilities of pre-professional students. One method for enhancing critical thinking is participation in role-playing simulation-based scenarios where students work together to resolve a potentially real situation. In this study, undergraduate nursing…

  16. Design and simulation of a fuel cell hybrid emergency power system for a more electric aircraft: Evaluation of energy management schemes

    Science.gov (United States)

    Njoya Motapon, Souleman

    As the aircraft industries are moving toward more electric aircraft (MEA), the electrical peak load seen by the main and emergency generators becomes higher than in conventional aircraft. Consequently, there is a major concern regarding the aircraft emergency system, which consists of a ram air turbine (RAT) or air driven generator (ADG), to fulfill the load demand during critical situations; particularly at low aircraft speed where the output power is very low. A potential solution under study by most aircraft manufacturers is to replace the air turbine by a fuel cell hybrid system, consisting of fuel cell combined with other high power density sources such as supercapacitors or lithium-ion batteries. To ensure the fuel cell hybrid system will be able to meet the load demand, it must be properly designed and an effective energy management strategy must be tested with real situations load profile. This work aims at designing a fuel cell emergency power system of a more electric aircraft and comparing different energy management schemes (EMS); with the goal to ensure the load demand is fully satisfied within the constraints of each energy source. The fuel cell hybrid system considered in this study consists of fuel cell, lithium-ion batteries and supercapacitors, along with associated DC-DC and DC-AC converters. The energy management schemes addressed are state-of-the-art, most commonly used energy management techniques in fuel cell vehicle applications and include: the state machine control strategy, the rule based fuzzy logic strategy, the classical PI control strategy, the frequency decoupling/fuzzy logic control strategy and the equivalent consumption minimization strategy (ECMS). Moreover, a new optimal scheme based on maximizing the instantaneous energy of batteries/supercapacitors, to improve the fuel economy is proposed. An off-line optimization based scheme is also developed to ascertain the validity of the proposed strategy in terms of fuel consumption

  17. Modelling Regional Surface Energy Exchange and Boundary Layer Development in Boreal Sweden — Comparison of Mesoscale Model (RAMS Simulations with Aircraft and Tower Observations

    Directory of Open Access Journals (Sweden)

    Meelis Mölder

    2012-10-01

    Full Text Available Simulation of atmospheric and surface processes with an atmospheric model (RAMS during a period of ten days in August 2001 over a boreal area in Sweden were compared to tower measurements and aircraft measurements of vertical profiles as well as surface fluxes from low altitude flights. The shape of the vertical profiles was simulated reasonably well by the model although there were significant biases in absolute values. Surface fluxes were less well simulated and the model showed considerable sensitivity to initial soil moisture conditions. The simulations were performed using two different land cover databases, the original one supplied with the RAMS model and the more detailed CORINE database. The two different land cover data bases resulted in relatively large fine scale differences in the simulated values. The conclusion of this study is that RAMS has the potential to be used as a tool to estimate boundary layer conditions and surface fluxes and meteorology over a boreal area but also that further improvement is needed.

  18. MISSILES AND AIRCRAFT (PART1

    Directory of Open Access Journals (Sweden)

    C.M. Meyer

    2012-02-01

    Full Text Available Many sources maintain that the role played by air power in the 1973 Yom Kippur War was important. Other interpretations state that control of air space over the battlefield areas, (either by aircraft or anti-aircraft defences, was vital.

  19. Analysis and Simulation of the Simplified Aircraft-Based Paired Approach Concept With the ALAS Alerting Algorithm in Conjunction With Echelon and Offset Strategies

    Science.gov (United States)

    Torres-Pomales, Wilfredo; Madden, Michael M.; Butler, Rickey W.; Perry, Raleigh B.

    2014-01-01

    This report presents analytical and simulation results of an investigation into proposed operational concepts for closely spaced parallel runways, including the Simplified Aircraft-based Paired Approach (SAPA) with alerting and an escape maneuver, MITRE?s echelon spacing and no escape maneuver, and a hybrid concept aimed at lowering the visibility minima. We found that the SAPA procedure can be used at 950 ft separations or higher with next-generation avionics and that 1150 ft separations or higher is feasible with current-rule compliant ADS-B OUT. An additional 50 ft reduction in runway separation for the SAPA procedure is possible if different glideslopes are used. For the echelon concept we determined that current generation aircraft cannot conduct paired approaches on parallel paths using echelon spacing on runways less than 1400 ft apart and next-generation aircraft will not be able to conduct paired approach on runways less than 1050 ft apart. The hybrid concept added alerting and an escape maneuver starting 1 NM from the threshold when flying the echelon concept. This combination was found to be effective, but the probability of a collision can be seriously impacted if the turn component of the escape maneuver has to be disengaged near the ground (e.g. 300 ft or below) due to airport buildings and surrounding terrain. We also found that stabilizing the approach path in the straight-in segment was only possible if the merge point was at least 1.5 to 2 NM from the threshold unless the total system error can be sufficiently constrained on the offset path and final turn.

  20. Simulation Analysis of Brushless DC Motors for Aircraft%飞机用无刷直流电动机系统仿真分析

    Institute of Scientific and Technical Information of China (English)

    马银龙; 尹航; 柯栋梁

    2011-01-01

    A novel method for modeling and simulation of the brushless DC motor system for Aircraft was presented. With this model,all the simulation of motor performance,fault protection,soft start can be realized. The mathematic model of the BLDCM was established. Under Simulink in Matlab 2010a,the simulation model of the BLDCM system can be modeled by the S-functions programming and modular design. Over-current,under-voltage and open phase protection were discussed to improve reliability. The reasonability was testified by the coincidence of the simulation results and theory analysis.%提出了一种新的飞机用无刷直流电动机的系统建模方法,该模型可以实现电机性能、故障保护、软起动的综合仿真.根据无刷直流电动机的数学模型,在Matlab 2010a的Simulink环境下,采用S函数和模块化建模方法,建立了相应的系统仿真模型.为提高可靠性,较详细地讨论了过流、欠压和缺相故障的保护.仿真实验结果与理论分析一致,验证了模型的合理有效性.

  1. 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...

  2. Aircraft Disinsection

    Science.gov (United States)

    Some countries may require aircraft coming from countries where certain insects or insect-borne diseases are present, such as malaria and Zika virus, to be treated with insecticide. Find out about regulation of pesticides for this treatment.

  3. Visualization of Aircraft Longitudinal-Axis Motion

    OpenAIRE

    Peter Kvasnica

    2015-01-01

    In this paper, the use of continuous mathematical models of an aircraft in an aircraft simulator is described. The models are of lower degree and less time-consuming for calculation. Computer implementation of the models capable to work faster and more accurately and efficiently is also described. The suggested approach allows to achieve the required precision at accelerated simulation speed using the continuous mathematical models of an aircraft. Frequency of the computation of continuous ma...

  4. System identification methods for aircraft flight control development and validation

    Science.gov (United States)

    Tischler, Mark B.

    1995-01-01

    System-identification methods compose a mathematical model, or series of models, from measurements of inputs and outputs of dynamic systems. The extracted models allow the characterization of the response of the overall aircraft or component subsystem behavior, such as actuators and on-board signal processing algorithms. This paper discusses the use of frequency-domain system-identification methods for the development and integration of aircraft flight-control systems. The extraction and analysis of models of varying complexity from nonparametric frequency-responses to transfer-functions and high-order state-space representations is illustrated using the Comprehensive Identification from FrEquency Responses (CIFER) system-identification facility. Results are presented for test data of numerous flight and simulation programs at the Ames Research Center including rotorcraft, fixed-wing aircraft, advanced short takeoff and vertical landing (ASTOVL), vertical/short takeoff and landing (V/STOL), tiltrotor aircraft, and rotor experiments in the wind tunnel. Excellent system characterization and dynamic response prediction is achieved for this wide class of systems. Examples illustrate the role of system-identification technology in providing an integrated flow of dynamic response data around the entire life-cycle of aircraft development from initial specifications, through simulation and bench testing, and into flight-test optimization.

  5. Analysis and Simulation of a Large Amphibian Aircraft Taxiing%大型水陆两栖飞机地面滑跑稳定性分析与仿真

    Institute of Scientific and Technical Information of China (English)

    韩纪军; 许锋; 聂宏

    2012-01-01

    The landing gear system works in concert with the safety of the aircraft's take off and landing directly, therefore it is one of the most important parts and systems of an aircraft. The landing gear design of an amphibian aircraft need to coordinate aerodynamics and liquid dynamics. It is a complicated dynamical problem, and it is the problem which is faced during the process of the large amphibian aircraft design nowadays. Depending on multi - body dynamical theories and the simulating plate of LMS Virtual. Lab, the dynamical model of a large amphibian aircraft taxiing process is proposed. By simulating the model, the a-nalysis of the heading stability during taxiing is conducted. The dynamical analysis and simulation of a large amphibian aircraft's heading taxiing is achieved.%起落装置直接关系到飞行器的起飞与着陆安全,是其重要部件和系统之一.大型水陆两栖飞机的起落架设计需在空气动力学与水动力学领域得到协调,是一个更为复杂的动力学问题,同时也是当前大型飞机研制中亟待解决的问题之一.基于多体动力学理论与LMS Virtual.Lab仿真环境,建立某大型水陆两栖飞机地面滑跑过程的动力学模型,通过对其地面对称滑跑等情况的仿真计算,着重对滑跑过程中的航向稳定性进行分析,实现水陆两栖飞机对称滑跑动力学分析与仿真.

  6. Airborne Conflict Management within Confined Airspace in a Piloted Simulation of DAG-TM Autonomous Aircraft Operations

    Science.gov (United States)

    Barmore, Bryan; Johnson, Edward; Wing, David J.; Barhydt, Richard

    2003-01-01

    A human-in-the-loop experiment was performed at the NASA Langley Research Center to study the feasibility of Distributed Air/Ground Traffic Management (DAG-TM) autonomous aircraft operations in highly constrained airspace. The airspace was constrained by a pair of special use airspace (SUA) regions on either side of the pilot s planned route. The available airspace was further varied by changing the separation standard for lateral separation between 3 nm and 5 nm. The pilot had to maneuver through the corridor between the SUA s, avoid other traffic and meet flow management constraints. Traffic flow management (TFM) constraints were imposed as a required time of arrival and crossing altitude at an en route fix. This is a follow-up study to work presented at the 4th USA/Europe Air Traffic Management R&D Seminar in December 2001. Nearly all of the pilots were able to meet their TFM constraints while maintaining adequate separation from other traffic. In only 3 out of 59 runs were the pilots unable to meet their required time of arrival. Two loss of separation cases are studied and it is found that the pilots need conflict prevention information presented in a clearer manner. No degradation of performance or safety was seen between the wide and narrow corridors. Although this was not a thorough study of the consequences of reducing the en route lateral separation, nothing was found that would refute the feasibility of reducing the separation requirement from 5 nm to 3 nm. The creation of additional, second-generation conflicts is also investigated. Two resolution methods were offered to the pilots: strategic and tactical. The strategic method is a closed-loop alteration to the Flight Management System (FMS) active route that considers other traffic as well as TFM constraints. The tactical resolutions are short-term resolutions that leave avoiding other traffic conflicts and meeting the TFM constraints to the pilot. Those that made use of the strategic tools avoided

  7. Using records from submarine, aircraft and satellite to evaluate climate model simulations of Arctic sea ice thickness

    Directory of Open Access Journals (Sweden)

    J. Stroeve

    2014-04-01

    Full Text Available Arctic sea ice thickness distributions from models participating in the World Climate Research Programme Coupled Model Intercomparison Project Phase 5 are evaluated against observations from submarines, aircraft and satellites. While it's encouraging that the mean thickness distributions from the models are in general agreement with observations, the spatial patterns of sea ice thickness are poorly represented in most models. The poor spatial representation of thickness patterns is associated with a failure of models to represent details of the mean atmospheric circulation pattern that governs the transport and spatial distribution of sea ice. The climate models as a whole also tend to underestimate the rate of ice volume loss from 1979 to 2013, though the multi-model ensemble mean trend remains within the uncertainty of that from the Pan-Arctic Ice Ocean Modeling and Assimilation System. These results raise concerns regarding the ability of CMIP5 models to realistically represent the processes driving the decline of Arctic sea ice and project the timing of when a seasonally ice-free Arctic may be realized.

  8. An Investigation of Two-Propeller Tilt Wing V/STOL Aircraft Flight Characteristics

    Science.gov (United States)

    1992-01-01

    aerodynamic input files or using manual input data. The output provides static aircraft longitudinal parameters for determining performance...wing aircraft so configured, the NASA Ames computer code TWANG is used for simulation of aircraft longitudinal stability and performance characteristics

  9. 虚拟现实仿真技术及在飞机装配中的应用%Virtual Reality Simulation and Its Application on Aircraft Assembling

    Institute of Scientific and Technical Information of China (English)

    王飞; 杨湘龙; 冯允成

    2001-01-01

    虚拟现实技术应用于仿真系统中,将极大地拓展仿真技术的研究和应用领域,具有广阔的理论及实际意义.利用目前先进的VRML(虚拟现实建模语言)进行三维环境构型的基础上,以Java语言设计仿真器并在三维环境下实时驱动对象进行运动,提出及完成了基于因特网浏览器的虚拟现实仿真技术方案,达到了虚拟现实仿真的基本要求,并以某飞机制造公司的波音737-700尾段的生产过程作为实际应用背景,进行了生产过程的可视化仿真及虚拟现实仿真的实证研究.%The mechanism of virtual reality simulation is deeply discussed. By means of the popular VRML 3D constructing language to build virtual reality scene and objects, and Java general programming language to code the mobile engine, which not only can complete the normal numeric simulation but also drive the virtual reality objects running according to the simulation event logic, this simulation system is realized on normal computer without any extra hardware requirements and meets the fundamental interactive requirements of virtual reality system.This fundamental, practical but powerful virtual reality simulation system is mainly applied on world wide web, and can be easily installed in any Java integrated development environment and extended to more utilized fields. Furthermore, a virtual reality simulation model for the assembling process of Boeing 737-700 aircraft is researched and constructed by such theory and methods. Finally, the future development of this virtual reality simulation mechanism is also discussed to show the prospect.

  10. A Role Simulation: Escalation of U.S. Troop Commitment in Vietnam, October 1961

    Science.gov (United States)

    Barber, Sandra Powell

    1978-01-01

    Describes a simulation designed to teach college students in an undergraduate political science course about foreign policy decision-making, conflict, and conflict resolution. An evaluation of role simulation as a teaching technique is included. (Author/DB)

  11. Aircraft noise prediction

    Science.gov (United States)

    Filippone, Antonio

    2014-07-01

    This contribution addresses the state-of-the-art in the field of aircraft noise prediction, simulation and minimisation. The point of view taken in this context is that of comprehensive models that couple the various aircraft systems with the acoustic sources, the propagation and the flight trajectories. After an exhaustive review of the present predictive technologies in the relevant fields (airframe, propulsion, propagation, aircraft operations, trajectory optimisation), the paper addresses items for further research and development. Examples are shown for several airplanes, including the Airbus A319-100 (CFM engines), the Bombardier Dash8-Q400 (PW150 engines, Dowty R408 propellers) and the Boeing B737-800 (CFM engines). Predictions are done with the flight mechanics code FLIGHT. The transfer function between flight mechanics and the noise prediction is discussed in some details, along with the numerical procedures for validation and verification. Some code-to-code comparisons are shown. It is contended that the field of aircraft noise prediction has not yet reached a sufficient level of maturity. In particular, some parametric effects cannot be investigated, issues of accuracy are not currently addressed, and validation standards are still lacking.

  12. Role of Mental Simulations in the Weight Loss Process.

    Science.gov (United States)

    Marszał-Wiśniewska, Magdalena; Jarczewska-Gerc, Ewa

    2016-01-01

    Two experiments were conducted to verify the influence of various mental simulations on the effectiveness and persistence of weight loss processes. In study one, 40 female students (aged 19-27, M = 23) who were eager to lose weight were randomly assigned to one of four groups: positive outcome simulation, process simulations, mixed simulations (process followed by negative outcome), and control (no simulations). Students from the mixed and process simulation groups lost significantly more weight after five weeks than participants from the outcome simulation and control groups. A total of 106 females (aged 19-45, M = 29) participated in study two, in which five types of mental simulations were tested. Besides the images used in study one, process followed by positive outcome simulations and negative outcome simulations were implemented. Results showed that process followed by positive outcome simulations lead to the highest persistence in the weight loss process, while process followed by negative outcome simulations induced the greatest reduction in weight. Both studies revealed self-regulatory benefits from mental simulations in difficult and long-term personal goal attainment.

  13. Airliner cabin air quality: emissions of organophosphates originating from aircraft engine oil. Experimental lab simulation and measurements on flight

    NARCIS (Netherlands)

    Houtzager, M.M.G.; Havermans, J.B.G.A.; Bos, J.G.H.; Makarem Akhlaghi, H.; Hijman, W.C.; Renesse van Duivenbode, J.A.D.; Jedynska, A.D.

    2014-01-01

    In our simulation experiments, using e.g., a dedicated emission chamber, the emission of organophosphates as tricresyl phosphate (TCP) was studied using turbine oil. Experiments were carried out at 250°C and 370°C. Subsequently field studies were carried out to detect the presence of TCPs in the coc

  14. New Methodology for Optimal Flight Control using Differential Evolution Algorithms applied on the Cessna Citation X Business Aircraft – Part 2. Validation on Aircraft Research Flight Level D Simulator

    Directory of Open Access Journals (Sweden)

    Yamina BOUGHARI

    2017-06-01

    Full Text Available In this paper the Cessna Citation X clearance criteria were evaluated for a new Flight Controller. The Flight Control Law were optimized and designed for the Cessna Citation X flight envelope by combining the Deferential Evolution algorithm, the Linear Quadratic Regulator method, and the Proportional Integral controller during a previous research presented in part 1. The optimal controllers were used to reach satisfactory aircraft’s dynamic and safe flight operations with respect to the augmentation systems’ handling qualities, and design requirements. Furthermore the number of controllers used to control the aircraft in its flight envelope was optimized using the Linear Fractional Representations features. To validate the controller over the whole aircraft flight envelope, the linear stability, eigenvalue, and handling qualities criteria in addition of the nonlinear analysis criteria were investigated during this research to assess the business aircraft for flight control clearance and certification. The optimized gains provide a very good stability margins as the eigenvalue analysis shows that the aircraft has a high stability, and a very good flying qualities of the linear aircraft models are ensured in its entire flight envelope, its robustness is demonstrated with respect to uncertainties due to its mass and center of gravity variations.

  15. Model Calculations of Changes in Tropospheric Ozone Over Europe and the Role of Surface Sources and Aircraft Emissions

    Energy Technology Data Exchange (ETDEWEB)

    Hov, Oe. [Bergen Univ. (Norway)

    1996-01-01

    This conference paper deals with a study of the impact of various sources of NO{sub x} on the ozone production in the free troposphere. A comprehensive two-dimensional zonally averaged chemistry/transport model and a three-dimensional meso-scale chemical transport (MCT) model are used in the study. Using the two-dimensional model, three surches of NO{sub x} in the upper troposphere were examined covering NO{sub x} produced by lightening, NO{sub x} (and NO{sub y}) brought to the upper troposphere from the planetary boundary layer by rapid vertical transport processes, and NO{sub x} emitted from aircraft. 4 refs.

  16. Evaluation of model-simulated source contributions to tropospheric ozone with aircraft observations in the factor-projected space

    Directory of Open Access Journals (Sweden)

    Y. Yoshida

    2008-03-01

    Full Text Available Trace gas measurements of TOPSE and TRACE-P experiments and corresponding global GEOS-Chem model simulations are analyzed with the Positive Matrix Factorization (PMF method for model evaluation purposes. Specially, we evaluate the model simulated contributions to O3 variability from stratospheric transport, intercontinental transport, and production from urban/industry and biomass burning/biogenic sources. We select a suite of relatively long-lived tracers, including 7 chemicals (O3, NOy, PAN, CO, C3H8, CH3Cl, and 7Be and 1 dynamic tracer (potential temperature. The largest discrepancy is found in the stratospheric contribution to 7Be. The model underestimates this contribution by a factor of 2–3, corresponding well to a reduction of 7Be source by the same magnitude in the default setup of the standard GEOS-Chem model. In contrast, we find that the simulated O3 contributions from stratospheric transport are in reasonable agreement with those derived from the measurements. However, the springtime increasing trend over North America derived from the measurements are largely underestimated in the model, indicating that the magnitude of simulated stratospheric O3 source is reasonable but the temporal distribution needs improvement. The simulated O3 contributions from long-range transport and production from urban/industry and biomass burning/biogenic emissions are also in reasonable agreement with those derived from the measurements, although significant discrepancies are found for some regions.

  17. Retrieval assessment using the microwave simulation tool for the High Altitude and LOng range aircraft HALO: humidity, temperature and hydrometeor profiles

    Science.gov (United States)

    Mech, M.; Crewell, S.; Orlandi, E.; Hirsch, L.

    2011-12-01

    New cloud observation techniques are needed to improve our understanding of the impact of clouds on the Earth's water cycle and radiation budget, which still represents one of the largest uncertainties in global and regional climate modelling. An airborne platform for such observation techniques will be provided by the new German research aircraft HALO (High Altitude LOng Range). In early 2013 a dedicated remote sensing mission NARVAL employing the microwave package HAMP (HALO Microwave Package; 36 channels microwave radiometer and 35.5 GHz Doppler radar), wind and water vapour lidar as well as auxiliary measurements will invest cloud systems in the North Atlantic in much higher detail than feasible on space-borne platforms. An advanced set of microwave remote cloud sensing instruments is to be operated on board of HALO. It consists of a cloud radar and a suite of passive radiometers in different frequency bands. The radar MIRA-36 operates at 35.5 GHz. The frequencies for the passive microwave radiometers were selected in allusion to the AMSU-A and -B sounder. In addition to the channels along the 60 GHz oxygen complex measurements along the 118 GHz oxygen line hint at the vertical distribution of liquid water that show a strong emission increase with frequency. This combination can be used for precipitation retrieval. In addition to include channels in the water vapor lines at 22.235 GHz and 183.31 GHz, information about the water vapor distribution throughout the troposphere can be retrieved. By including higher microwave channels sensitive to scattering in the ice phase various precipitation retrieval algorithms can be compared with measurements from HAMP. Retrieval algorithms and potential flight patterns are investigated using a simulation test bed combining cloud model and radiative transfer simulations. Thereby the cloud resolving model simulations and the forward radiative transfer calculations include a one- and two-moment cloud microphysical scheme with

  18. 舰载机蒸汽弹射热力学仿真分析%The thermodynamic simulation and analysis of the aircraft steam catapults

    Institute of Scientific and Technical Information of China (English)

    梁傲; 陈辉; 张国磊; 郭家敏; 周科; 杨诚

    2016-01-01

    通过对蒸汽弹射器基本工作原理的了解,运用动力学与热力学知识对其进行分析,考虑风速和开槽汽缸导热及漏气对弹射的影响,在合理的假设前提下利用Matlab/Simulink仿真软件建立出了蒸汽弹射热力学动态仿真模型,并以美国C-13型蒸汽弹射器为对象进行仿真分析,得出弹射过程中舰载机的加速度、速度、位移和储汽筒和汽缸内压力、温度以及漏汽量及耗汽量等参数的变化规律,对进一步了解蒸汽弹射具有一定意义。%The paper using the knowledge of dynamics and thermodynamics and the understanding of the basic prin-ciple of steam catapult, developing an analysis on the steam ejection of carrier-based aircraft, which is considering the thermal conductivity, the wind speed and the cylinder leakage effects on ejection;furthermore, a thermodynamic steam cata-pult out of a dynamic simulation model is established under the reasonable assumptions of the use of Matlab/Simulink simu-lation software. Meanwhile, a simulation analysis on C-13 type steam ejection of America shows that the acceleration, the velocity, the displacement, the steam reservoir, the inner pressure of the cylinder, the temperature, the quantity of the steam leakage and the steam consumption etc. and such kind changing rule of parameters, which are of great significance to have a further understanding of the steam ejection.

  19. Model simulations and aircraft measurements of vertical, seasonal and latitudinal O3 and CO distributions over Europe

    Directory of Open Access Journals (Sweden)

    H. Fischer

    2006-01-01

    Full Text Available During a series of 8 measurement campaigns within the SPURT project (2001-2003, vertical profiles of CO and O3 have been obtained at subtropical, middle and high latitudes over western Europe, covering the troposphere and lowermost stratosphere up to ~14 km altitude during all seasons. The seasonal and latitudinal variation of the measured trace gas profiles are compared to simulations with the chemical transport model MATCH. In the troposphere reasonable agreement between observations and model predictions is achieved for CO and O3, in particular at subtropical and mid-latitudes, while the model overestimates (underestimates CO (O3 in the lowermost stratosphere particularly at high latitudes, indicating too strong simulated bi-directional exchange across the tropopause. By the use of tagged tracers in the model, long-range transport of Asian air masses is identified as the dominant source of CO pollution over Europe in the free troposphere.

  20. An Introduction to Thermodynamic Performance Analysis of Aircraft Gas Turbine Engine Cycles Using the Numerical Propulsion System Simulation Code

    Science.gov (United States)

    Jones, Scott M.

    2007-01-01

    This document is intended as an introduction to the analysis of gas turbine engine cycles using the Numerical Propulsion System Simulation (NPSS) code. It is assumed that the analyst has a firm understanding of fluid flow, gas dynamics, thermodynamics, and turbomachinery theory. The purpose of this paper is to provide for the novice the information necessary to begin cycle analysis using NPSS. This paper and the annotated example serve as a starting point and by no means cover the entire range of information and experience necessary for engine performance simulation. NPSS syntax is presented but for a more detailed explanation of the code the user is referred to the NPSS User Guide and Reference document (ref. 1).

  1. Aircraft Survivability. Susceptibility Reduction. Fall 2010

    Science.gov (United States)

    2010-01-01

    to determine the degree of control available with manual manipulation of engine throttles for various transport aircraft. Simulations included...Boeing 727, 737, 747, 757, 767, 777, MD-11, MD-90, C-17, and Airbus A320 and A300 transport aircraft. Preliminary missile impact effects were...shown, for most aircraft tested, that using only manual TOC it is very difficult to make a safe runway landing due to difficulty in controlling the

  2. An Aircraft Lifecycle Approach for the Cost-Benefit Analysis of Prognostics and Condition-Based Maintenance-Based on Discrete-Event Simulation

    Science.gov (United States)

    2014-10-02

    BC) influence airline revenues in the lifecycle CBA. The initial investment cost C0 is assumed as 50 Mio . US$ (aircraft list price in 2008 less an...Value Ticket price - EC [US$] 2008 111 Ticket price - BC [US$] 2008 334 Aircraft price C0 (incl. 35% discount) [ Mio . US$] 2008 50 Labor rate

  3. Environmental Simulation and Experimental Study of Aircraft Icing and Deicing on Ground%飞机地面积/除冰环境模拟与试验研究

    Institute of Scientific and Technical Information of China (English)

    陈斌; 张浩; 王立文

    2011-01-01

    飞机地面积冰是飞机进入冬季安全飞行的重要隐患,很多飞行事故都是因为没有清除飞机表面的积冰而造成的.基于对飞机地面积/除冰的真实环境的分析,在低温湿热试验箱中模拟积/除冰时的大气条件,对机翼积/除冰进行试验研究.通过改变环境温度、除冰液温度、流量、浓度等影响因素,利用光纤式结冰传感器得到不同环境条件下,除冰液参数对除冰过程的影响数据,并对这些数据进行了分析.试验结果表明该装置能有效地模拟飞机地面积/除冰过程,数据分析显示飞机地面结冰过程主要受外界环境温度,湿度(空气的水含量)的影响;对飞机地面除冰来说,除冰液温度参数是除冰效果达到最佳的关键因素.%Aircraft icing on ground is a major danger for flight safety in winter, and numerous flight accidents could attribute to not having cleared the ice on the aircraft body before takeoff. An atmosphere icing weather condition was simulated in a low temperature cabin to imitate aircraft deicing on ground based on the study of aircraft ice mechanism on ground. Then several conditions, such as deicing fluids temperature , flow rate and scale, were changed to study the influencing factors on the aircraft deicing process u-sing fiber-optic icing sensors. Experimental results show that the aircraft deicing simulation environment could effectively simulate the deicing/icing process. Moreover, analysis results reveal that the environment temperature, humidity are the main parameters for the aircraft icing process and the deicing fluids temperature is the key factor to obtain ideal deicing effect.

  4. Simulations and Experiments of Hot Forging Design and Evaluation of the Aircraft Landing Gear Barrel Al Alloy Structure

    Science.gov (United States)

    Ram Prabhu, T.

    2016-04-01

    In the present study, the hot forging design of a typical landing gear barrel was evolved using finite element simulations and validated with experiments. A DEFORM3D software was used to evolve the forging steps to obtain the sound quality part free of defects with minimum press force requirements. The hot forging trial of a barrel structure was carried out in a 30 MN hydraulic press based on the simulation outputs. The tensile properties of the part were evaluated by taking samples from all three orientations (longitudinal, long transverse, short transverse). The hardness and microstructure of the part were also investigated. To study the soundness of the product, fluorescent penetrant inspection and ultrasonic testing were performed in order to identify any potential surface or internal defects in the part. From experiments, it was found that the part was formed successfully without any forging defects such as under filling, laps, or folds that validated the effectiveness of the process simulation. The tensile properties of the part were well above the specification limit (>10%) and the properties variation with respect to the orientation was less than 2.5%. The part has qualified the surface defects level of Mil Std 1907 Grade C and the internal defects level of AMS 2630 Class A (2 mm FBh). The microstructure shows mean grain length and width of 167 and 66 µm in the longitudinal direction. However, microstructure results revealed that the coarse grain structure was observed on the flat surface near the lug region due to the dead zone formation. An innovative and simple method of milling the surface layer after each pressing operation was applied to solve the problem of the surface coarse grain structure.

  5. A Methodology for the Determination of Rotary Wing Aircraft Vulnerabilities in Air-to-Air Combat Simulation.

    Science.gov (United States)

    1984-11-23

    results of executing the metodology is proposed. 7. :i1-i * I .- 1 SECURITY CLASSIFICATION OF THIS PAGEIbhen DaIa EnternE 0 0 0 0 0 0 0 0 0 0 0_ 0...SIMULATION A THESIS Presented to The Faculty of the Division of Graduate Studies * by Kenneth L. Travis In Partial Fulfillment of the Requirements for...It is most difficult, if not impossible to adequately model the unbounded human decision making process. Our case here is confounded by different

  6. The Role of Knowledge Objects in Participatory Ergonomics Simulation

    DEFF Research Database (Denmark)

    Andersen, Simone Nyholm

    2015-01-01

    Participatory ergonomics simulations, taking place in simulation labs, have the tendency to get detached from the surrounding design process, resulting in a knowledge gap. Few studies in the human factors and ergonomics field have applied knowledge management based object concepts in the study...... in generation of ergonomics knowledge and transfer of this knowledge to actors in the surrounding design process. Design actors receiving simulation documenting objects interpret and transform the represented knowledge according to their local context and experiences....

  7. Parametric Modeling Simulation Study on Locking Mechanism for Aviation Aircraft%航空飞行器锁机构参数化建模仿真研究

    Institute of Scientific and Technical Information of China (English)

    刘霞; 王三民; 单宁; 孙远涛

    2013-01-01

    Locking mechanism of aviation aircraft is very important for perform mission.But its study is centralized on experiment field.In order to avoid motion interference of locking mechanism efficiency and design it reasonably,the method of parametric modeling and kinematics simulation was put forward in the paper.The optimum model of dimension calculation was established based on strength analysis of locking mechanism.Its dimension parameter was design.Its solid model was realized based on parametric method.The kinematics simulation model of locking mechanism was established.And its motion state was simulated.The results show that designed locking mechanism has good motion continuity and has no motion interference.It can realize close and open effectively.In the working process of locking mechanism,lock hook is close to lock bar with steady speed before 32 second.They piece on speedily and realize lock tightly after 32 second.Acceleration of lock hook increases quickly and produces larger speed and force in the instancy of lock tighten.This agrees satisfactorily with actual situation.Above results show that the model can simulate the actual motion state of aviation aircraft locking mechanism effectively and offer some theoretical basis for design and use of locking mechanism.%研究锁机构优化设计,对航空飞行器任务完成起着至关重要的作用.由于以往研究多集中在实验仿制方面,开展仿真理论研究的较少,针对上述问题提,出了一种能有效避免锁机构运动干涉,合理设计锁机构的参数化建模和运动学仿真模型.利用锁机构强度分析的尺寸优化方法,设计了锁机构厚度、宽度以及销轴与杆件的接触长度等尺寸参数,实现了锁机构的参数化实体建模,建立了锁机构的运动学仿真模型,进行运动状态仿真.结果表明,设计的锁机构运动连续性好,无运动干涉现象,能实现有效闭合、开启.锁钩工作行程中,第32s

  8. Non-linear Numerical Simulation of Bird Impact on Aircraft Windshield%鸟撞飞机风挡非线性数值分析

    Institute of Scientific and Technical Information of China (English)

    朱书华; 王跃全; 郭亮; 张立圣; 童明波

    2011-01-01

    采用非线性有限元法,基于ABAQUS/Explicit软件平台及内嵌的材料用户定义子程序(VUMAT),建立了鸟撞飞机风挡的力学分析模型.比较了有限元模型中玻璃骨架、弧框和橡胶垫片对风挡动响应分析结果的影响,并与全尺寸风挡鸟撞试验数据进行了对比.对比结果表明,考虑了玻璃骨架、弧框和橡胶垫片的有限元模型所计算得到的位移、应变曲线与试验实测曲线的一致性有了改善.最后,探讨了玻璃骨架、橡胶垫片的厚度和弹性模量对风挡抗鸟撞能力的影响规律,为风挡的抗鸟撞设计及改型提供参考.%A finite element model (FEM) of bird impact on the windshield is established via the nonlinear finite element method, combined with the user-defined materials subroutine (VUMAT) of the ABAQUS/Explicit software. The dynamic response of bird strike on aircraft windshield is analyzed in two different configurations, with and without the surrounding structure frame, skin and rubber layer. By comparing the simulation results and the full-scale experiment data, the results of FEM with the surrounding structure have a better agreement with the experiments in the instantaneous deformation of bird and windshield, the damage modes of the windshield, the displacement curves and the strain curves of the measured points on the windshield. In addition, the sensitivities of the design parameters of aircraft windshield, including skin thickness, skin elastic modulus, rubber thickness, and rubber elastic modulus are discussed on the windshield capability against bird-strike comprehensively.

  9. Simulation Research of Temperature Control in Aircraft Ground Air Conditioning Carts%飞机地面空调车温度控制的仿真研究

    Institute of Scientific and Technical Information of China (English)

    潘琢金; 王丽伟; 杨华; 张大伟

    2012-01-01

    The temperature control system of aircraft ground air conditioning carts is a complex system with model imprecise, nonlinear, time - varying and uncertain work environment. The traditional PID control has high overshoot, slow response, poor ability of anti - interference and so on. There is "degenerate" phenomenon based on the genetic algorithm PID parameters tuning, so stability is poor, and it is easy to fall into local optimum based on the particle swarm optimization, so accuracy is not high. This paper proposed a genetic - particle swarm optimization PID control method with good stability, high accuracy, strong anti - interference. It utilized traditional PID method, combined with their respective advantages of the genetic algorithm and the particle swarm optimization algorithm, and a-chieved the PID parameters online tuning. It has been proved by the Matlab simulation experimental results that this algorithm has small overshoot, fast response, high precision, strong anti -interference ability, and other advantages. Meanwhile, it has greatly improved the performance of the PID control. And it is very suitable for the aircraft air conditioning temperature control.%研究优化飞机地面空调车温控制问题,由于飞机地面空调车温度控制是非线性、时变性强的系统,工作环境不确定性,面对复杂系统温控模型不准确,传统的PID控制存在超调量大、响应速度慢、抗干扰能力弱等缺点.为提高温度控制精度,提出了一种新的稳定性好、精度高、抗干扰能力强的遗传-粒子群PID控制方法.结合传统的PID方法,遗传算法和粒子群算法的各自优点,实现了PID参数的在线整定.通过在matlab上进行仿真,实验结果证明算法具有超调量小、响应速度快、精度高、抗干扰能力强等优点,PID控制性能有显著提高,为飞机地面空调车的温度控制设计提供了依据.

  10. 基于仿真的作战飞机管道加油调度优化研究%Scheduling Optimization of Combat Aircraft Pipeline Refueling Based on Simulation

    Institute of Scientific and Technical Information of China (English)

    王世宏; 雍岐东; 李横; 岳亮

    2013-01-01

      针对多机种作战飞机管道油料加注调度优化的现实问题,通过研究作战飞机从到达基地到加油完毕的油料加注周期,提出了一种新的管道加油口选择策略,并基于此策略研制了以作战飞机数量和油料加注时间为仿真结束条件的2种GPSSW仿真程序模型。通过多次仿真实验,结果表明:该策略优于基于调度人员经验的“即空即用”管道加油口选择策略,可有效提高作战飞机油料加注效率,并能实现有限管道加油口的合理分配。%In order to solve the practical scheduling optimization problem of multitype combat aircraft pipeline refueling,a new selection strategy is proposed for pipeline refueling adapters according to the combat aircraft refueling cycles from aircraft arriv⁃ing airport to fueling over. Based on the new selection strategy,two types of general purpose system simulation world(GPSSW)mod⁃els,which are conditional on combat aircrafts quantity and refueling time,are programmed. Through numerical simulation of two types of models,the test results indicate that the new selection strategy gains an advantage over the traditional selection based on ex⁃periences of scheduling personnel,increases the refueling efficiency of combat aircraft,and achieves the oil filler of limited pipeline channels’reasonable arrangement.

  11. The Role of Crop Systems Simulation in Agriculture and Environment

    Science.gov (United States)

    Over the past 30 to 40 years, simulation of crop systems has advanced from a neophyte science with inadequate computing power into a robust and increasingly accepted science supported by improved software, languages, development tools, and computer capabilities. Crop system simulators contain mathe...

  12. The role of simulation in teaching pediatric resuscitation: current perspectives

    Directory of Open Access Journals (Sweden)

    Lin Y

    2015-03-01

    Full Text Available Yiqun Lin,1 Adam Cheng2 1KidSIM-ASPIRE Simulation Research Program, Alberta Children's Hospital, University of Calgary, Calgary, AB, Canada; 2KidSIM-ASPIRE Research Program, Department of Pediatrics, Division of Emergency Medicine, University of Calgary, Alberta Children's Hospital, Calgary, AB, Canada Abstract: The use of simulation for teaching the knowledge, skills, and behaviors necessary for effective pediatric resuscitation has seen widespread growth and adoption across pediatric institutions. In this paper, we describe the application of simulation in pediatric resuscitation training and review the evidence for the use of simulation in neonatal resuscitation, pediatric advanced life support, procedural skills training, and crisis resource management training. We also highlight studies supporting several key instructional design elements that enhance learning, including the use of high-fidelity simulation, distributed practice, deliberate practice, feedback, and debriefing. Simulation-based training is an effective modality for teaching pediatric resuscitation concepts. Current literature has revealed some research gaps in simulation-based education, which could indicate the direction for the future of pediatric resuscitation research. Keywords: simulation, pediatric resuscitation, medical education, instructional design, crisis resource management, health care

  13. Simulation of Noise-Cancelling in the Cockpit of an Aircraft Using Two-Rate Hybrid Neural Network

    Directory of Open Access Journals (Sweden)

    ASTROV, I.

    2007-11-01

    Full Text Available This paper presents the two-rate hybrid neural network (TRHNN for processing of noisy signal. The received TRHNN consists of "fast" ADAptive LInear NEuron neural network (FADALINENN and "slow" radial basis neural network (SRBNN. The illustrative design example - noise-cancelling of noisy pilot's voice pattern - was carried out using the TRHNN. The received TRHNN has high speed of signal processing. This example demonstrates that the proposed TRHNN is capable not only to recognize the pilot's voice in the noisy voice pattern, but also to restore the pilot's voice. The simulation results with use the software package Simulink show the computing procedure and applicability of the TRHNNs for fast-acting signal processing and analysis in real-time flight conditions.

  14. Super-Droplet Approach to Simulate Precipitating Trade-Wind Cumuli - Comparison of Model Results with RICO Aircraft Observations

    CERN Document Server

    Arabas, Sylwester

    2012-01-01

    In this study we present a series of LES simulations employing the Super-Droplet Method (SDM) for representing aerosol, cloud and rain microphysics. SDM is a particle-based and probabilistic approach in which a Monte-Carlo type algorithm is used for solving the particle collisions and coalescence process. The model does not differentiate between aerosol particles, cloud droplets, drizzle or rain drops. Consequently, it covers representation of such cloud-microphysical processes as: CCN activation, drizzle formation by autoconversion, accretion of cloud droplets, self-collection of raindrops and precipitation including aerosol wet deposition. Among the salient features of the SDM, there are: (i) the robustness of the model formulation (i.e. employment of basic principles rather than parametrisations) and (ii) the ease of comparison of the model results with experimental data obtained with particle-counting instruments. The model set-up used in the study is based on observations from the Rain In Cumulus over Oc...

  15. "Reluctant Participants" in Role Play Simulations: Stage Fright or Bewilderment?

    Science.gov (United States)

    Saunders, Danny

    1985-01-01

    Discusses factors contributing to participant reluctance in role playing--isolation of role play from the curriculum; lack of interest because of perceived irrelevance to social psychological themes; and acting anxiety. A two-step design which involves gradual role play introduction and observation by reluctant participants is suggested as a…

  16. Power and Politics in the Classroom: The Effect of Student Roles in Simulations

    Science.gov (United States)

    Baranowski, Michael; Weir, Kimberly

    2010-01-01

    We argue that power roles can make a significant difference in how students experience in-class simulations. To test this, students who participated in Congressional simulations in one of the author's introduction to American politics classes were surveyed concerning their views of Congress, the legislative process, and the simulation experience.…

  17. Student Perceptions of a Role-Playing Simulation in an Introductory International Relations Course

    Science.gov (United States)

    Giovanello, Sean P.; Kirk, Jason A.; Kromer, Mileah K.

    2013-01-01

    An emerging assumption in undergraduate political science education is that role-playing simulations are an effective teaching tool. While previous studies have addressed the pedagogical advantages of simulations as compared to more traditional teaching techniques, less attention has been paid to student perceptions of these simulations. This…

  18. 基于SPH的小型飞机水上迫降姿态数值仿真%Numerical Simulation of Light Aircraft Ditching Attitude Based on SPH Method

    Institute of Scientific and Technical Information of China (English)

    张盛; 闫家益; 朱书华; 童明波

    2014-01-01

    适航条例中要求飞机必须具备良好的水上迫降性能。早期主要通过试验方法研究飞机的水上迫降性能,但是试验耗资巨大、时间周期长。采用一种新型的数值模拟方法研究飞机水上迫降问题,利用光滑质点流体动力学( SPH)方法模拟三级波浪,建立小型飞机水上迫降模型。考虑到飞机姿态角和起落架收放状态对迫降性能的影响,建立7种计算工况,模拟得到相应的加速度响应和姿态角变化。以飞机在迫降过程中应该受到较小的加速度响应和姿态角变化为依据,通过对比分析计算结果,最终给出12°姿态角、起落架收起为最优迫降状态的结论,为飞机迫降的入水姿态提供技术支持。%Abtsract :Under the requirement of airworthiness regulation ,one aircraft must have a good ditching per-formance .In the past ,tests were implemented to evaluate the aircraft ditching performance ,however tests have really some disadvantages:vast investment and time-consuming .This paper applied numerical sim-ulation technique to research aircraft ditching performance .The Smoothed Particle Hydrodynamics ( SPH) method was introduced to simulate sea waves and a aircraft ditching model was then built .In consideration of influences of the state of landing gear and attitude angle on ditching performance ,seven simulation con-ditions were designed ,the corresponding acceleration responses and attitude angle changes were simula-ted.Under the condition that aircraft should get a lower drag force and smaller change in amplitude ,a fi-nal conclusion of optimum ditching attitude , viz landing gear retraction with attitude angle of 12 °, was drawn from the comparative analysis of simulation results ,which is valuable to aircraft ditching solution .

  19. [Role playing as an essential element of simulation procedures in medicine].

    Science.gov (United States)

    Dieckmann, Peter; Rall, Marcus; Eich, Christoph; Schnabel, Kai; Jünger, Jana; Nikendei, Christoph

    2008-01-01

    Role playing is an important element of virtually all simulation-based procedures. An improved understanding for methodological aspects facilitates its goal-oriented use in education and training, research and examinations. In the present paper we describe how different forms of role play are used in different simulation-based procedures. We describe a plausibility study from skills labs demonstrating that the introduction of role-playing can increase perceived realism. Finally we derive practical suggestions for the conduction of role plays in medical simulation.

  20. Origins of Aircraft-Damaging Clear-Air Turbulence during the 9 December 1992 Colorado Downslope Windstorm: Numerical Simulations and Comparison with Observations.

    Science.gov (United States)

    Clark, Terry L.; Hall, William D.; Kerr, Robert M.; Middleton, Don; Radke, Larry; Ralph, F. Martin; Neiman, Paul J.; Levinson, David

    2000-04-01

    horizontal vortex tubes (HVTs) aligned with the mean flow. These HVTs remained aloft while they propagated downstream at about the elevation of the aircraft incident, and evidence for such a vortex was seen by the lidar. The model and observations suggest that one of these intense vortices may have caused the aircraft incident.Reports of strong surface gusts were intermittent along the Front Range during the period of this study. The model showed that interactions between the gravity waves and flow-aligned jet stream undulations result in isolated occurrences of strong surface gusts in line with observations. The simulations show that strong shears on the upper and bottom surfaces of the jet stream combine to provide an episodic `downburst of turbulence.' In the present case, the perturbations of the jet stream provide a funnel-shaped shear zone aligned with the mean flow that acts as a guide for the downward transport of turbulence resulting from breaking gravity waves. The physical picture for the upper levels is similar to the surface gusts described by Clark and Farley resulting from vortex tilting. The CAT feeding into this funnel came from all surfaces of the jet stream with more than half originating from the vertically inclined shear zones on the bottom side of the jet stream. Visually the downburst of turbulence looks similar to a rain shaft plummeting to the surface and propagating out over the plains leaving relatively quiescent conditions behind.

  1. Virtual reality: emerging role of simulation training in vascular access.

    Science.gov (United States)

    Davidson, Ingemar J A; Lok, Charmaine; Dolmatch, Bart; Gallieni, Maurizio; Nolen, Billy; Pittiruti, Mauro; Ross, John; Slakey, Douglas

    2012-11-01

    Evolving new technologies in vascular access mandate increased attention to patient safety; an often overlooked yet valuable training tool is simulation. For the end-stage renal disease patient, simulation tools are effective for all aspects of creating access for peritoneal dialysis and hemodialysis. Based on aviation principles, known as crew resource management, we place equal emphasis on team training as individual training to improve interactions between team members and systems, cumulating in improved safety. Simulation allows for environmental control and standardized procedures, letting the trainee practice and correct mistakes without harm to patients, compared with traditional patient-based training. Vascular access simulators range from suture devices, to pressurized tunneled conduits for needle cannulation, to computer-based interventional simulators. Simulation training includes simulated case learning, root cause analysis of adverse outcomes, and continual update and refinement of concepts. Implementation of effective human to complex systems interaction in end-stage renal disease patients involves a change in institutional culture. Three concepts discussed in this article are as follows: (1) the need for user-friendly systems and technology to enhance performance, (2) the necessity for members to both train and work together as a team, and (3) the team assigned to use the system must test and practice it to a proficient level before safely using the system on patients.

  2. Nonlinear analysis of commercial aircraft impact on a reactor building—Comparison between integral and decoupled crash simulation

    Energy Technology Data Exchange (ETDEWEB)

    Siefert, A., E-mail: siefert@woelfel.de; Henkel, F.O.

    2014-04-01

    Since 9/11, the crash of a commercial aeroplane on the reactor building of a nuclear power plant is a realistic design scenario. Before that the structural behaviour under a crash of a military plane was investigated by a procedure using load-time functions (Riera, 1968). Thereby, the computation of the load-time-function was based on a conceptional model considering the main stiffness parts and masses by discrete elements. With respect to the homogeneous structural set-up of a military plane, the application of this model and the derived load-time-function applied as lumped load case seems very feasible. Contrary thereto the structural set-up of a commercial aeroplane, with e.g. the high mass concentration of the turbine or the high stiffness of the wing box compared to other parts, is different. This can be counteracted by using a more detailed finite element (FE) model for the computation of the load-time-function and by dividing the load case for the reactor building in different main load zones. Although this represents a more detailed investigation, the procedure of using a load-time-function still has the disadvantage to separate the real scenario into two steps. Thereby, the direct interaction between the structure and the aeroplane including all softening effects due to material respectively structural compliances is neglected. This leads to the general conclusion that by applying load-time-functions the results are conservative compared to the real behaviour. Due to the increased capabilities of numerical software solutions it is also possible nowadays to carry out integral crash simulations, combining all effects within one simulation. Compared to the procedure of using load-time-functions, the numerical complexity and therefore the amount of work for this integral method are increased. Within this paper both procedures (load-time function by detailed FE-model and the integral method) are exemplarily compared to each other by a crash analysis of an

  3. Path-tracking control of a tractor-aircraft system

    Science.gov (United States)

    Wang, Nengjian; Liu, Hongbo; Yang, Wanhui

    2012-12-01

    An aircraft tractor plays a significant role as a kind of important marine transport and support equipment. It's necessary to study its controlling and manoeuvring stability to improve operation efficiency. A virtual prototyping model of the tractor-aircraft system based on Lagrange's equation of the first kind with Lagrange mutipliers was established in this paper. According to the towing characteristics, a path-tracking controller using fuzzy logic theory was designed. Direction control herein was carried out through a compensatory tracking approach. Interactive co-simulation was performed to validate the path-tracking behavior in closed-loop. Simulation results indicated that the tractor followed the reference courses precisely on a flat ground.

  4. Path-tracking Control of a Tractor-aircraft System

    Institute of Scientific and Technical Information of China (English)

    Nengjian Wang; Hongbo Liu; Wanhui Yang

    2012-01-01

    An aircraft tractor plays a significant role as a kind of important marine transport and support equipment.It's necessary to study its controlling and manoeuvring stability to improve operation efficiency.A virtual prototyping model of the tractor-aircraft system based on Lagrange's equation of the first kind with Lagrange mutipliers was established in this paper.According to the towing characteristics,a path-tracking controller using fuzzy logic theory was designed.Direction control herein was carried out through a compensatory tracking approach.Interactive co-simulation was performed to validate the path-tracking behavior in closed-loop.Simulation results indicated that the tractor followed the reference courses precisely on a flat ground.

  5. Role of virtual reality simulation in endoscopy training

    Institute of Scientific and Technical Information of China (English)

    Louis; Harpham--Lockyer; Faidon--Marios; Laskaratos; Pasquale; Berlingieri; Owen; Epstein

    2015-01-01

    Recent advancements in virtual reality graphics and models have allowed virtual reality simulators to be incorporated into a variety of endoscopic training programmes. Use of virtual reality simulators in training programmes is thought to improve skill acquisition amongst trainees which is reflected in improved patient comfort and safety. Several studies have already been carried out to ascertain the impact that usage of virtual reality simulators may have upon trainee learning curves and how this may translate to patient comfort. This article reviews the available literature in this area of medical education which is particularly relevant to all parties involved in endoscopy training and curriculum development. Assessment of the available evidence for an optimal exposure time with virtual reality simula-tors and the long-term benefits of their use are also discussed.

  6. Role of virtual reality simulation in endoscopy training.

    Science.gov (United States)

    Harpham-Lockyer, Louis; Laskaratos, Faidon-Marios; Berlingieri, Pasquale; Epstein, Owen

    2015-12-10

    Recent advancements in virtual reality graphics and models have allowed virtual reality simulators to be incorporated into a variety of endoscopic training programmes. Use of virtual reality simulators in training programmes is thought to improve skill acquisition amongst trainees which is reflected in improved patient comfort and safety. Several studies have already been carried out to ascertain the impact that usage of virtual reality simulators may have upon trainee learning curves and how this may translate to patient comfort. This article reviews the available literature in this area of medical education which is particularly relevant to all parties involved in endoscopy training and curriculum development. Assessment of the available evidence for an optimal exposure time with virtual reality simulators and the long-term benefits of their use are also discussed.

  7. Rain simulator role in creating of Erosion Potential Method (EPM)

    Science.gov (United States)

    Gavrilovic, Zoran; Stefanovic, Milutin; Milovanovic, Irina

    2010-05-01

    Soil erosion is a natural process that depends on many variables factor. Unlike the other factors rain is meteoric phenomenon of short duration and intensity variation. This feature caused the application of rain simulators in the field of erosion research. During the development of erosion potential method, it was concluded that there is too large dissipation of observed erosion data. The first use of simulators did not give better results, because the rain simulator had no impact on other factors of erosion. Therefore, the research continued in the laboratory where the use of rain simulators takes a series of data for various intensity and duration of rain. Other factors are controlled for each series of measurements were constant. These data enabled more precise definition of the numerical coefficients and procedures of erosion potential method (EPM), which is known in the scientific public as Gavrilovic method. The paper will appear applied a combination of experimental erosion field and laboratory measurements obtained using rain simulators. Key words: Erosion, torrents, meteorology, climate, Rain simulator

  8. Training in surgical oncology - the role of VR simulation.

    Science.gov (United States)

    Lewis, T M; Aggarwal, R; Rajaretnam, N; Grantcharov, T P; Darzi, A

    2011-09-01

    There have been dramatic changes in surgical training over the past two decades which have resulted in a number of concerns for the development of future surgeons. Changes in the structure of cancer services, working hour restrictions and a commitment to patient safety has led to a reduction in training opportunities that are available to the surgeon in training. Simulation and in particular virtual reality (VR) simulation has been heralded as an effective adjunct to surgical training. Advances in VR simulation has allowed trainees to practice realistic full length procedures in a safe and controlled environment, where mistakes are permitted and can be used as learning points. There is considerable evidence to demonstrate that the VR simulation can be used to enhance technical skills and improve operating room performance. Future work should focus on the cost effectiveness and predictive validity of VR simulation, which in turn would increase the uptake of simulation and enhance surgical training. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. Computational analysis of aircraft pressure relief doors

    Science.gov (United States)

    Schott, Tyler

    Modern trends in commercial aircraft design have sought to improve fuel efficiency while reducing emissions by operating at higher pressures and temperatures than ever before. Consequently, greater demands are placed on the auxiliary bleed air systems used for a multitude of aircraft operations. The increased role of bleed air systems poses significant challenges for the pressure relief system to ensure the safe and reliable operation of the aircraft. The core compartment pressure relief door (PRD) is an essential component of the pressure relief system which functions to relieve internal pressure in the core casing of a high-bypass turbofan engine during a burst duct over-pressurization event. The successful modeling and analysis of a burst duct event are imperative to the design and development of PRD's to ensure that they will meet the increased demands placed on the pressure relief system. Leveraging high-performance computing coupled with advances in computational analysis, this thesis focuses on a comprehensive computational fluid dynamics (CFD) study to characterize turbulent flow dynamics and quantify the performance of a core compartment PRD across a range of operating conditions and geometric configurations. The CFD analysis was based on a compressible, steady-state, three-dimensional, Reynolds-averaged Navier-Stokes approach. Simulations were analyzed, and results show that variations in freestream conditions, plenum environment, and geometric configurations have a non-linear impact on the discharge, moment, thrust, and surface temperature characteristics. The CFD study revealed that the underlying physics for this behavior is explained by the interaction of vortices, jets, and shockwaves. This thesis research is innovative and provides a comprehensive and detailed analysis of existing and novel PRD geometries over a range of realistic operating conditions representative of a burst duct over-pressurization event. Further, the study provides aircraft

  10. Role of convective transport on tropospheric ozone chemistry revealed by aircraft observations during the wet season of the AMMA campaign

    Directory of Open Access Journals (Sweden)

    G. Ancellet

    2008-08-01

    Full Text Available During the wet season of the African Monsoon Multidisciplinary Analyses (AMMA campaign, airborne measurements of several chemical species were made onboard the French Falcon-20 (FF20 aircraft. The scientific flights were planned in order to document, on one hand the regional distribution of trace gas species related to the oxidizing capacity of the troposphere, and on the other hand their spatial variability in the outflow of mesoscale convective systems (MCSs. The main objectives of this paper are the analysis of the main transport processes responsible for the observed variability, and the discussion of differences and similarities related to the convective transport by 4 different MCSs. This work is needed before using this data set for future studies of the convective transport of chemical species or for modeling work in the frame of the AMMA project. Regarding the regional distribution, five air masses types have been identified using the Lagrangian particle dispersion model FLEXPART, and by considering relationship between the measured trace gas concentrations (O3, CO, NOx, H2O, and hydroperoxides. This paper specifically discusses the advantage of hydroperoxide measurements in order to document the impact of recent or aged convection. The highest values of O3 are found to be related to transport from the subtropical tropopause region into the mid-troposphere at latitudes as low as 10° N. The lowest ozone values have been always explained by recent uplifting from the monsoon layer where O3 is photochemically destroyed. Regarding the analysis of the MCS outflow, the CO and H2O2 enhancements are related to the age and the southernmost position of the MCS. The analysis of the long range transport of the air masses where convection occurred, shows a connection with the Persian Gulf emissions for the largest CO concentrations in MCS outflow. However for our

  11. 自行高炮CGF实体智能机动行为仿真%Simulation of intelligent dynamic behavior for anti-aircraft gun element CGF entity

    Institute of Scientific and Technical Information of China (English)

    王鹏; 朱元昌; 邸彦强

    2012-01-01

    CGF系统是未来作战仿真所必备的技术支持,在介绍CGF系统的基础上,提出了以智能仿真为依托,兼顾底层机动自主和高层决策可控的设计思路.研究了自行高炮连CGF实体在机动性能方面的仿真,通过对高炮机动性能中物理行为和认知行为的研究,运用BP神经网络实现CGF实体智能机动行为的建模,并建立了动态障碍的规避模块.较好解决了中各车行进中出现的实体碰撞问题,结合实际应用对模型进行了可行性验证.%CGF system is an indispensable technical support of the future fight emulation. Based on introducing the CGF, put forward the design scheme combined higher level decision controllability with underlying mobility autonomy, study the emulation of the an-ti-aircraft gun element CGF entity in flexible performance, through the study of physical behavior and the intelligent behavior, using BP neural network to realize simulation of intelligent dynamic behavior for the CGF entity, set up the evading module of dynamic obstacle, which solve the problem of colliding of the entity in the course entered of every garage, at last verify the feasibility of the model in con-sideration of practical application.

  12. Chemistry in aircraft plumes

    Energy Technology Data Exchange (ETDEWEB)

    Kraabol, A.G.; Stordal, F.; Knudsen, S. [Norwegian Inst. for Air Research, Kjeller (Norway); Konopka, P. [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Wessling (Germany). Inst. fuer Physik der Atmosphaere

    1997-12-31

    An expanding plume model with chemistry has been used to study the chemical conversion of NO{sub x} to reservoir species in aircraft plumes. The heterogeneous conversion of N{sub 2}O{sub 5} to HNO{sub 3}(s) has been investigated when the emissions take place during night-time. The plume from an B747 has been simulated. During a ten-hour calculation the most important reservoir species was HNO{sub 3} for emissions at noon. The heterogeneous reactions had little impact on the chemical loss of NO{sub x} to reservoir species for emissions at night. (author) 4 refs.

  13. Modular Electric Propulsion Test Bed Aircraft Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A hybrid electric aircraft simulation system and test bed is proposed to provide a dedicated development environment for the rigorous study and advancement of hybrid...

  14. The Role of Semantics in Games and Simulations

    NARCIS (Netherlands)

    Kraker, J.K. de.; Smelik, R.M.; Tutenel, T.; Bidarra, R.

    2008-01-01

    Powerful graphics hardware is enabling strong improvements in both the appearance and the complexity of virtual worlds for games and simulations. However, current practices in the design and development of virtual worlds mostly resemble high-tech variants of traditional handcrafts, resulting in

  15. The Role of Simulation Games: Supplement or Central Delivery Vehicle?

    Science.gov (United States)

    Fritzsche, David J.

    1980-01-01

    Reports the results of an experiment assessing the effectiveness of two different approaches to using simulation games in a marketing course. In one, the game was used as a supplement to the standard lecture/discussion format; in the other, it was used as the central delivery vehicle. Twenty-one references are listed. (Author/LLS)

  16. 多轮多支柱式飞机起落架运动特性仿真研究%Simulation Research on Multiple Wheels and Multiple Strut Aircraft Landing Gear’s Kinetic Characteristic

    Institute of Scientific and Technical Information of China (English)

    王博; 林皓

    2014-01-01

    In order to assess the handling characteristics of the aircraft at taking off and landing stage ,for a com‐plex aircraft landing gear systems ,the single strut landing gear system which is composed by tires ,shock strut system ,brake system and nose wheel steering system is studied ,including force analysis ,torque characteristic and its delivery process .Based on the linear theory and the Matlab/Simulink ,all the strut kinetic characteristics are superimposed together ,that constitutes a simulation model of the system .Moreover ,embedded in aircraft six degree of freedom model and been simulated ,including acceleration taxiing characteristics ,high/low speed turns characteristics ,take‐off characteristics ,landing characteristics and brake characteristics .The model is used in an aircraft moving base simulator for flight test .The simulation result indicates that this model accu‐rately reflects the aircraft attitude response in the process of plane’s taking off and landing .%为了评估起降阶段的飞机操控特性,针对某型飞机多轮多支柱式起落架系统,研究组成单个起落架支柱的轮胎、缓冲器、刹车系统、前轮转弯等部件的受力、力矩特性及传递过程。基于线性理论,将多个支柱运动特性叠加,运用Matlab/Simulink软件工具,建立整个系统的仿真模型。嵌入某型飞机六自由度运动解算模型进行飞机落震、加速滑跑、高低速转弯、起飞离地、着陆接地、刹车减速等仿真验证,并在某型飞机动基座模拟器上进行飞行试验。结果表明:该起落架模型各项功能完善,能够正确反映飞机姿态响应过程,飞机起降过程感受与真实飞机基本一致。

  17. Static Aeroelasticity in Combat Aircraft.

    Science.gov (United States)

    1986-01-01

    Simulation Maneuverability Performance System Integration Design Load Spectren FIG. 1 HIGH PERFORMANCE AIRCRAFT DESIGN Simulation has a great potential...Aeroelasticity has also a great effect on the flight control system design. If the basic control powers are reduced by increasing dynamic pressure...Components Flight Envelope Structure Concept a Total Aircraf Analysis FIG, 2 BASIC DATAS FOR AEROELASTIC DESIGN STUDIES Aeroelastic activities are now devided

  18. Improvements in Aircraft Gas Turbine Engines for the 90s

    Directory of Open Access Journals (Sweden)

    Arun Prasad

    1993-10-01

    Full Text Available The gas turbine propulsion system has been playing the most significant role in the evolution and development of present-day aircraft, and has become the limiting technology for developing most new aircraft. However, the jet engine still remains the preferred propulsion choice. Aircraft gas turbines in one form or the other, viz. turbojet, turbofan, turboprop or turboshaft, have been used in commercial passenger aircraft, high performance military aircraft and in rotary wing aircraft (helicopters. The emphasis in engine development programmes world over seems to be in reducing fuel consumption, increasing thrust and in reducing weight.

  19. Research on Unsteady Numerical Simulation of Propeller Aircraft Slipstream%螺旋桨飞机滑流非定常数值模拟研究

    Institute of Scientific and Technical Information of China (English)

    麻蓉; 高飞飞; 颜洪; 梁益华

    2016-01-01

    The effect of propeller slipstream on the aerodynamic characteristics has been analyzed using the unsteady numerical method,which based on sliding mesh technology. This simulation used our inhouse solver based on structured mesh in this paper. Unsteady numerical method using sliding patched mesh was introduced detailedly in three aspects including patched boundary,the patched grid and the interpolation method. And the procedure to implement this method is presented generally. On this basis,the three di-mensional flow field around a turbo-prop wing body configuration is simulated especially. The effects of propeller slipstream on the characteristics of the flow field and aerodynamic are analyzed. Through the comparison with the experiment data,the feasibility and accuracy of sliding patched technology are veri-fied. The results show that the flow field of the slipstream can be simulated factually by the numerical method based on the sliding patched technology. This study provides a valid numerical simulation method for propeller-driven aircraft design and possesses higher utility value in engineering.%采用非定常数值模拟方法,基于滑移网格技术,分析研究螺旋桨滑流对全机气动特性的干扰影响。用多块结构网格数值模拟软件,从搭接边界建立、搭接网格生成、流场插值传递3个方面对螺旋桨滑移搭接网格的数值模拟方法进行全面详细的介绍,并且阐述基于该技术的非定常数值模拟方法。在此基础上,开展螺旋桨飞机模型验证计算,分析研究螺旋桨滑流对全机流场和气动性能的影响,通过与风洞实验数据的对比分析,验证滑移搭接网格技术的可行性与准确性。研究结果表明,基于滑移搭接网格技术的螺旋桨滑流数值模拟,可以真实反映螺旋桨滑流流场特性,为螺旋桨类飞机的设计评估提供一种有效的数值模拟手段,在工程方面具有重要的实用价值。

  20. Development of a Technique and Method of Testing Aircraft Models with Turboprop Engine Simulators in a Small-scale Wind Tunnel - Results of Tests

    Directory of Open Access Journals (Sweden)

    A. V. Petrov

    2004-01-01

    Full Text Available This report presents the results of experimental investigations into the interaction between the propellers (Ps and the airframe of a twin-engine, twin-boom light transport aircraft with a Π-shaped tail. An analysis was performed of the forces and moments acting on the aircraft with rotating Ps. The main features of the methodology for windtunnel testing of an aircraft model with running Ps in TsAGI’s T-102 wind tunnel are outlined.The effect of 6-blade Ps slipstreams on the longitudinal and lateral aerodynamic characteristics as well as the effectiveness of the control surfaces was studied on the aircraft model in cruise and takeoff/landing configurations. The tests were conducted at flow velocities of V∞ = 20 to 50 m/s in the ranges of angles of attack α =  -6 to 20 deg, sideslip angles of β = -16 to 16 deg and blade loading coefficient of B 0 to 2.8. For the aircraft of unusual layout studied, an increase in blowing intensity is shown to result in decreasing longitudinal static stability and significant asymmetry of the directional stability characteristics associated with the interaction between the Ps slipstreams of the same (left-hand rotation and the empennage.

  1. Aircraft Electric Secondary Power

    Science.gov (United States)

    1983-01-01

    Technologies resulted to aircraft power systems and aircraft in which all secondary power is supplied electrically are discussed. A high-voltage dc power generating system for fighter aircraft, permanent magnet motors and generators for aircraft, lightweight transformers, and the installation of electric generators on turbine engines are among the topics discussed.

  2. Opinion Leaders' Role in Innovation Diffusion : A Simulation Study

    NARCIS (Netherlands)

    van Eck, P.S.; Leeflang, P.S.H.; Jager, W.

    2011-01-01

    This study investigates the critical role that opinion leaders (or influentials) play in the adoption process of new products. Recent existing reseach evidence indicates a limited effect of opinion leaders on diffusion processes, yet these studies take into account merely the network position of opi

  3. Study on Impedance Characteristics of Aircraft Cables

    Directory of Open Access Journals (Sweden)

    Weilin Li

    2016-01-01

    Full Text Available Voltage decrease and power loss in distribution lines of aircraft electric power system are harmful to the normal operation of electrical equipment and may even threaten the safety of aircraft. This study investigates how the gap distance (the distance between aircraft cables and aircraft skin and voltage frequency (variable frequency power supply will be adopted for next generation aircraft will affect the impedance of aircraft cables. To be more precise, the forming mechanism of cable resistance and inductance is illustrated in detail and their changing trends with frequency and gap distance are analyzed with the help of electromagnetic theoretical analysis. An aircraft cable simulation model is built with Maxwell 2D and the simulation results are consistent with the conclusions drawn from the theoretical analysis. The changing trends of the four core parameters of interest are analyzed: resistance, inductance, reactance, and impedance. The research results can be used as reference for the applications in Variable Speed Variable Frequency (VSVF aircraft electric power system.

  4. Hydrogen chloride heterogeneous chemistry on frozen water particles in subsonic aircraft plume. Laboratory studies and modelling

    Energy Technology Data Exchange (ETDEWEB)

    Persiantseva, N.V.; Popovitcheva, O.B.; Rakhimova, T.V. [Moscow State Univ. (Russian Federation)

    1997-12-31

    Heterogeneous chemistry of HCl, as a main reservoir of chlorine content gases, has been considered after plume cooling and ice particle formation. The HCl, HNO{sub 3}, N{sub 2}O{sub 5} uptake efficiencies by frozen water were obtained in a Knudsen-cell flow reactor at the subsonic cruise conditions. The formation of ice particles in the plume of subsonic aircraft is simulated to describe the kinetics of gaseous HCl loss due to heterogeneous processes. It is shown that the HCl uptake by frozen water particles may play an important role in the gaseous HCl depletion in the aircraft plume. (author) 14 refs.

  5. THE ROLE AND PLACE OF THE «NATIONAL PLAN FOR SCIENCE AND TECHNOLOGY IN THE AIRCRAFT INDUSTRY FOR THE PERIOD UP TO 2025 AND THE SUBSEQUENT PROSPECT» IN STRATEGIC PLANNING DOCUMENTS

    Directory of Open Access Journals (Sweden)

    V. A. Hariton

    2014-01-01

    Full Text Available A brief overview of the strategic planning documents in the aviation industry, defined the legal status of the developed "National Plan for Science and Technology in the aircraft industry for the period up to 2025 and the subsequent prospect" assesses its role and place in the strategic planning documents, the relationship with the main documents. Disclosed structure of the National Plan and the goal of scientific and technological potential, defined by the National Plan.

  6. Anti-aircraft Gun Fire Control Algorithm and Simulation Based on Ballistic%基于外弹道的高炮火控算法与仿真

    Institute of Scientific and Technical Information of China (English)

    李强; 欧阳攀

    2014-01-01

    In order to adapt to the improved target speed and maneuverability in modern warfare, and enhance the capability of anti-aircraft gun to attack air moving target,it has to give full play to the trajectory based on fire control computation precision advantages and accelerate the calculating speed. Through the integration of the external ballistic real-time calculating with calculate iterative algorithm and initial choice,a completely based on the ballistic calculating rapid fire control decoding algorithm system is received. The simulation results verified the external trajectory real-time calculating accuracy when compared with the firing table data. The solving hit problem of uniform linear motion and acceleration linear motion is analyzed with the usage of GDI + graphics functions and C# language. Analysis results show that the algorithm is feasible and provides a reference for fire-control system.%为适应现代战争中目标速度与机动性的提高,增强高炮打击空中运动目标能力,需要充分发挥基于外弹道火控解算精度高的优点,并提高解算速度。通过整合外弹道实时解算和解命中迭代算法与初值选择,得到了一种完全基于外弹道解算的快速火控解算算法体系。经过仿真计算,并将仿真结果与射表数据对比,验证了外弹道实时解算的准确性。利用GDI+图形功能基于C#语言仿真分析了匀速与匀加速直线运动目标的解命中问题,验证了算法的可行性,为火控系统的研制提供了参考。

  7. Advanced aircraft electric power system

    Energy Technology Data Exchange (ETDEWEB)

    Segrest, J.D.

    1981-01-01

    The role of electric energy in both military and commercial aircraft increases in importance with every advancement in airframe performance and avionic technology. Microcircuits and volatile memories impact power continuity and quality, digital flight control and stability augmentation require high reliability. This paper presents the system concept, hardware development and status of the Navy program.

  8. 飞机除冰液加热系统单神经元PID控制仿真%Single Neuron PID Control Simulation of Aircraft Deicing Fluids Heating System

    Institute of Scientific and Technical Information of China (English)

    陈斌; 杨宏祯; 王立文

    2012-01-01

    Aiming at the temperature turbulence problem of aircraft deicing heating system, this paper presents the single neuron PID control strategy which combines the advantage of conventional PID control with artificial neuron control. By building the mathematical model of aircraft deicing fluids heating system on the basis of data gathered by experiments, simulation of single neuron PID control is executed. Results show that the single neuron PID control strategy performs effectively on the temperature turbulence problem of aircraft deicing fluids heating system.%针对在飞机除冰液加热系统中管路流量脉动造成温度波动的问题,提出单神经元PID控制策略,建立飞机除冰液加热系统的数学模型,并使用Matlab进行仿真.结果表明,单神经元PID控制策略对飞机除冰液加热过程的控制,比常规的PID控制器速率快、稳定性高.

  9. Who's Driving? The role and training of the human patient simulation operator.

    Science.gov (United States)

    Gantt, Laura

    2012-11-01

    Within the airline industry, where much of simulation-based education originated, cockpit simulators are operated by current or former pilots whose expertise ensures the authenticity of the training experience. As yet, identifying the most appropriate person to run a patient simulator has not been translated into healthcare. Furthermore, few training resources exist for those who must learn the intricacies of the relationship between patient simulators, simulation scenarios, and educational objectives. This article reviews literature related to the role, educational preparation, and training of the patient simulator operator and explores solutions to the uncertainty about the difference between simulator operators and technicians. Because simulators are operationally intensive and because scarce faculty may be best used to facilitate student learning within the laboratory, the tendency has been to use a variety of personnel to manage patient simulators. Recommendations for standardizing the role of the operator that are consistent with the pedagogical purposes of simulation are offered. Potential questions are posed, and methods for future work are discussed.

  10. Simulation, Role-Playing, and Sociodrama in the Social Studies. With an Annotated Bibliography.

    Science.gov (United States)

    Garvey, Dale M.; Garvey, Sancha K.

    1967-01-01

    Classroom experience for social studies students in simulation, role-playing, and sociodrama provides not only an interesting way of learning, but also an appreciation for the complexity and interdependence of social systems in the modern world. Role-playing requires a student to assume an identity other than his own to increase his understanding…

  11. Advanced risk assessment of the effects of graphite fibers on electronic and electric equipment, phase 1. [simulating vulnerability to airports and communities from fibers released during aircraft fires

    Science.gov (United States)

    Pocinki, L. S.; Kaplan, L. D.; Cornell, M. E.; Greenstone, R.

    1979-01-01

    A model was developed to generate quantitative estimates of the risk associated with the release of graphite fibers during fires involving commercial aircraft constructed with graphite fiber composite materials. The model was used to estimate the risk associated with accidents at several U.S. airports. These results were then combined to provide an estimate of the total risk to the nation.

  12. Reliability and optimization, application to safety of aircraft structures

    OpenAIRE

    Chu, Liu

    2016-01-01

    Tremendous struggles of researchers in the field of aerodynamic design and aircraft production were made to improve wing airfoil by optimization techniques. The development of computational fluid dynamic (CFD) in computer simulation cuts the expense of aerodynamic experiment while provides convincing results to simulate complicated situation of aircraft. In our work, we chose a special and important part of aircraft, namely, the structure of wing.Reliability based optimization is one of the m...

  13. The emerging role of screen based simulators in the training and assessment of colonoscopists.

    Science.gov (United States)

    Cunningham, Morven; Fernando, Bimbi; Berlingieri, Pasquale

    2010-07-01

    Incorporation of screen based simulators into medical training has recently gained momentum, as advances in technology have coincided with a government led drive to increase the use of medical simulation training to improve patient safety with progressive reductions in working hours available for junior doctors to train. High fidelity screen based simulators hold great appeal for endoscopy training. Potentially, their incorporation into endoscopy training curricula could enhance speed of acquisition of skills and improve patient comfort and safety during the initial phase of learning. They could also be used to demonstrate competence as part of the future relicensing and revalidation of trained endoscopists. Two screen based simulators are widely available for lower gastrointestinal endoscopy training, with a third recently produced in prototype. The utility of these simulators in lower gastrointestinal endoscopy training has been investigated, and construct and expert validity has been shown. Novices demonstrate a learning curve with simulator training that appears to represent real learning of colonoscopy skills. This learning transfers well to the real patient environment, with improvements in performance and patient discomfort scores in subsequent initial live colonoscopy. The significant limitations of currently available screen based simulators include cost implications, and restrictions on a role in certification and revalidation. Many questions remain to be answered by future research, including how best to incorporate screen based simulators into a colonoscopy training programme, their role in training in therapeutic endoscopy and the impact of simulator training on patient safety.

  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. Negotiating the role of the professional nurse: The pedagogy of simulation: a grounded theory study.

    Science.gov (United States)

    Walton, Joni; Chute, Elizabeth; Ball, Lynda

    2011-01-01

    Simulation is the mainstay of laboratory education in health sciences, yet there is a void of pedagogy-the art and science of teaching. Nursing faculty does not have adequate evidence-based resources related to how students learn through simulation. The research questions that were addressed were as follows: (a) How do students learn using simulation? (b) What is the process of learning with simulations from the students' perspective? (c) What faculty teaching styles promote learning? and (d) How can faculty support students during simulation? Grounded theory methodology was used to explore how senior baccalaureate nursing students learn using simulation. Twenty-six students participated in this research study. Sixteen nursing students who completed two semesters of simulation courses volunteered for in-depth audio-taped interviews. In addition, there were two focus groups with five senior students in each group who validated findings and identified faculty teaching styles and supportive interventions. Negotiating the Role of the Professional Nurse was the core category, which included the following phases (I) feeling like an imposter, (II) trial and error, (III) taking it seriously, (IV) transference of skills and knowledge, and (V) professionalization. Faculty traits and teaching strategies for teaching with simulation were also identified. A conceptual model of the socialization process was developed to assist faculty in understanding the ways students learn with simulation and ways to facilitate their development. These findings provide a midrange theory for the pedagogy of simulation and will help faculty gain insight and help to assimilate into teaching-learning strategies.

  16. Hail damage to typical aircraft surfaces.

    Science.gov (United States)

    Hayduk, R. J.

    1972-01-01

    Severe structural damage can occur when aircraft collide with hailstones. Consequently, methods of predicting hail damage to airplane surfaces are needed by the aircraft designer. This paper describes an analytical method of predicting the dent depth and final deformed shape for simple structural components impacted by hailstones. The solution was accomplished by adapting the DEPROSS computer program to the problem of normal impact of hail on flat metallic sheets and spherical metallic caps. Experimental data and analytical predictions are presented for hail damage to typical aircraft surfaces along with a description of the hail gun and hail simulation technique used in the experimental study.

  17. AIRCRAFT MAINTENANCE HANGAR

    National Research Council Canada - National Science Library

    GEAMBASU Gabriel George

    2017-01-01

    .... 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...

  18. Design Quality Control Model for Aircraft Based on Computer Simulation and Statistics%基于计算机仿真和数据统计的飞机设计质量控制模型

    Institute of Scientific and Technical Information of China (English)

    袁聪聪; 张传超

    2014-01-01

    In view of those problems which are dififcult to form combat ability, low usual readiness low wartime mission sustainability, high use and support cost, poor affordability for aircraft after servicing and uniqueness of aircraft development, from the systematic and continuous perspective, demonstration the same goal between effectiveness evaluation of ILS(Integrated Logistics Support) and design quality for aircraft, evaluation index parameters measuring aircraft design quality were determined, and the evaluation model was built, a method based on computer simulation and statistical principles was put out, a prototype system was developed and verified. Validation result shows that the system principle is correct, and the model is rational, and the method is scientific and effective. This method has systematic, phased, continuous and economic control characteristics, can solve current problems such as the subjectivity of aircraft design quality control.%针对飞机投入使用后难以形成战斗力、平时战备完好、战时任务持续能力低、使用与保障费用高昂、经济可承受性差等问题以及飞机研制的独特性,本文从系统性和持续性改进的角度出发,论证了飞机综合保障效能评价和质量控制目标一致性,确定了衡量飞机设计质量的评估指标参数,构建了飞机设计质量评价模型,提出了一种计算机仿真和数据统计原理的飞机设计质量控制方法,研发了原型系统,并进行了验证。验证结果表明,该系统原理正确、模型合理、科学有效。该方法具有系统性、阶段性、持续性、经济性控制的特点,能够解决飞机设计质量控制中存在的主观性等问题。

  19. Improving transient analysis technology for aircraft structures

    Science.gov (United States)

    Melosh, R. J.; Chargin, Mladen

    1989-01-01

    Aircraft dynamic analyses are demanding of computer simulation capabilities. The modeling complexities of semi-monocoque construction, irregular geometry, high-performance materials, and high-accuracy analysis are present. At issue are the safety of the passengers and the integrity of the structure for a wide variety of flight-operating and emergency conditions. The technology which supports engineering of aircraft structures using computer simulation is examined. Available computer support is briefly described and improvement of accuracy and efficiency are recommended. Improved accuracy of simulation will lead to a more economical structure. Improved efficiency will result in lowering development time and expense.

  20. Unmanned aircraft systems

    Science.gov (United States)

    Unmanned platforms have become increasingly more common in recent years for acquiring remotely sensed data. These aircraft are referred to as Unmanned Airborne Vehicles (UAV), Remotely Piloted Aircraft (RPA), Remotely Piloted Vehicles (RPV), or Unmanned Aircraft Systems (UAS), the official term used...

  1. Future aircraft networks and schedules

    Science.gov (United States)

    Shu, Yan

    2011-07-01

    computational results of these large-scale instances. To validate the models and solution algorithms developed, this thesis also compares the daily flight schedules that it designs with the schedules of the existing airlines. Furthermore, it creates instances that represent different economic and fuel-prices conditions and derives schedules under these different conditions. In addition, it discusses the implication of using new aircraft in the future flight schedules. Finally, future research in three areas---model, computational method, and simulation for validation---is proposed.

  2. Leveraging America’s Aircraft Carrier Capabilities. Exploring New Combat and Noncombat Roles and Missions for the U.S. Carrier Fleet

    Science.gov (United States)

    2006-01-01

    in the center of the Mediterranean Sea, roughly 100 miles south of Sicily . British aircraft, submarines, and surface ships based on Malta inflicted...Noncombat Vignettes 91 Most refugees flee to the north, toward the Florida Keys. To com- plicate matters, there are three tropical -storm systems in the

  3. Control of Next Generation Aircraft and Wind Turbines

    Science.gov (United States)

    Frost, Susan

    2010-01-01

    The first part of this talk will describe some of the exciting new next generation aircraft that NASA is proposing for the future. These aircraft are being designed to reduce aircraft fuel consumption and environmental impact. Reducing the aircraft weight is one approach that will be used to achieve these goals. A new control framework will be presented that enables lighter, more flexible aircraft to maintain aircraft handling qualities, while preventing the aircraft from exceeding structural load limits. The second part of the talk will give an overview of utility-scale wind turbines and their control. Results of collaboration with Dr. Balas will be presented, including new theory to adaptively control the turbine in the presence of structural modes, with the focus on the application of this theory to a high-fidelity simulation of a wind turbine.

  4. Research on Safe Flight of the Outboard Wing Rupturing Aircraft based on CFD Simulation%基于CFD仿真的外翼断裂飞机安全飞行研究

    Institute of Scientific and Technical Information of China (English)

    姚武文; 蔡开龙

    2016-01-01

    The flight of the aircraft with outboard wing rupturing is a special problem about pneumatics and flight con-trol.The analysis model about the special pneumatics problem is set up by the CFD emulation method,and the control method about outboard wing rupturing aircraft aviating safely is brought forward.By the simulation computing,the conclu-sion is gained that the opposite damage most limit of the outboard wing based on the aileron balance method is 14.2%,and the opposite damage most limit of the outboard wing based on the side flight balance method is 24.5%.It provides the refer-ence and evaluation method for the aircraft with outboard wing rupturing flying.%针对外翼断裂飞机安全飞行问题,采用CFD 仿真方法,建立了针对该特殊气动问题的分析模型,提出了外翼断裂飞机安全飞行控制方法,并通过仿真计算得到,基于副翼平衡法的外翼相对损伤极限为14.2%,基于侧飞平衡法的外翼相对损伤极限为24.5%,为战时外翼断裂飞机带伤飞行提供了参考和评估方法。

  5. Simulating the Role of Visual Selective Attention during the Development of Perceptual Completion

    Science.gov (United States)

    Schlesinger, Matthew; Amso, Dima; Johnson, Scott P.

    2012-01-01

    We recently proposed a multi-channel, image-filtering model for simulating the development of visual selective attention in young infants (Schlesinger, Amso & Johnson, 2007). The model not only captures the performance of 3-month-olds on a visual search task, but also implicates two cortical regions that may play a role in the development of…

  6. What Can Students Learn in an Extended Role-Play Simulation on Technology and Society?

    Science.gov (United States)

    Loui, Michael C.

    2009-01-01

    In a small course on technology and society, students participated in an extended role-play simulation for two weeks. Each student played a different adult character in a fictional community, which faces technological decisions in three scenarios set in the near future. The three scenarios involved stem cell research, nanotechnology, and privacy.…

  7. Teacher's Skill Improvement by Role-Play and Simulations on Collaborative Educational Virtual Worlds

    Science.gov (United States)

    Lorenzo, Carlos-Miguel

    2014-01-01

    This study looked at teachers' role-play and simulations in order to increase teachers' skills in psycho-pedagogical support on educational virtual worlds. We put forward a proposal to encourage the use of 3D scenarios where teachers can improve their skills for situations of cultural and ethical concerns that require a high level…

  8. Role-Playing Simulation as a Communication Tool in Community Dialogue: Karkonosze Mountains Case Study

    Science.gov (United States)

    Krolikowska, Karolina; Kronenberg, Jakub; Maliszewska, Karolina; Sendzimir, Jan; Magnuszewski, Piotr; Dunajski, Andrzej; Slodka, Anna

    2007-01-01

    This article describes a process of role-playing simulation (RPS) as it was used during an educational exercise in community dialogue in the Karkonosze Mountains region of southwest Poland. Over the past decade Karkonosze National Park, a regional tourist magnet, has provided an excellent example of environmental conflict emerging from the…

  9. Manned Flight Simulator (MFS)

    Data.gov (United States)

    Federal Laboratory Consortium — The Aircraft Simulation Division, home to the Manned Flight Simulator (MFS), provides real-time, high fidelity, hardware-in-the-loop flight simulation capabilities...

  10. CFD Numerical Simulation of Carrier-Based Aircraft Warming Machine with the Island Influence%舰载机暖机对舰岛影响的CFD数值模拟

    Institute of Scientific and Technical Information of China (English)

    徐鸣; 岳奎志; 郁大照

    2015-01-01

    为了对机舰适配性提供技术支持,文章研究了舰载机暖机对航母舰岛的热作用影响。首先,采用CATIA软件,建立航母与舰载机的3D数字样机;其次,采用Fluent软件,基于标准k-ε方程的湍流模型和三维N-S方程的控制理论,对航母与舰载机系统的数字样机进行CFD数值模拟,数值模拟了甲板风和燃气流相互作用和热交换作用下对舰岛的影响,并得出航母流场流线图、速度云图、动压云图和温度云图。数值模拟结果表明:暖机时,舰载机发动机的燃气流对舰岛及周边设备影响很大;最后,提出参考建议:舰岛及附近设备应进行抗热性能改进以满足暖机要求,人员禁止进入燃气流影响到的高温区域。%To provide technical support for aircraft carrier suitability, thermal coupling effect between the island and the warming-up carrier-based aircraft was proposed. A 3D digital mock-up of a carrier and aircrafts was established in CA⁃TIA, and a CFD (Computational Fluid Dynamics) numerical simulation was calculated based on k-εtwo-equation turbu⁃lent mode and Navier-Stokes equation. Considering the impact of the coupling and heat exchange between wind and com⁃bustion-gas flow on the island, the simulation results included flow streamline distribution, velocity distribution, pressure distribution and temperature distribution. The numerical simulation showed that the combustion-gas flow of the warming-up engines had great influence on the island the peripheral equipment. And the suggestion is that the island and peripheral equipment need to increase heat resisting property, and people are prohibited from entering the high temperature area.

  11. A Note on the Role of Meridional Wind Stress Anomalies and Heat Flux in ENSO Simulations

    Institute of Scientific and Technical Information of China (English)

    ZHU Jieshun; SUN Zhaobo; ZHOU Guangqing

    2007-01-01

    Four comparative experiments and some supplementary experiments were conducted to examine the role of meridional wind stress anomalies and heat flux variability in ENSO simulations by using a highresolution Ocean General Circulation Model (OGCM). The results indicate that changes in the direction and magnitude of meridional wind stress anomalies have little influence on ENSO simulations until meridional wind stress anomalies are unrealistically enlarged by a factor of 5.0. However, evidence of an impact on ENSO simulations due to heat flux variability was found. The simulated Ni(n)o-3 index without the effect of heat flux anomalies tended to be around 1.0° lower than the observed, as well as the control run, during the peak months of ENSO events.

  12. Pre-industrial to Present Day Chemistry Model Simulations: The Role of Different Forcings

    Science.gov (United States)

    Young, P. J.; Lamarque, J.; Kinnison, D. E.; Vitt, F.

    2011-12-01

    We will present the results from several CAM-Chem simulations that span 1850-2010. Simulations where one forcing is fixed at 1850 (or 1930) levels are compared against a "base" simulation, where all the forcings evolve through time. The "fixed" simulations respectively hold (1) methane, (2) all surface/aloft emissions, (3) only aerosol emissions, (4) sea surface temperatures/CO2 (i.e. climate) at their 1850 level, and (5) CFCs at their 1930 level. We will examine the sensitivity of the ozone budget and methane lifetime results under these various scenarios. In particular, we will discuss the potential role of complex interactions in defining the tropospheric ozone burden change. We will make use of those results as a basis for the understanding of the spread in fields from the ongoing Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP).

  13. Ergonomic analysis for a regional aircraft interior design.

    OpenAIRE

    Flavia Renata Dantas Alves Silva

    2007-01-01

    The purpose of this work is to develop a preliminary interior design of a regional aircraft considering ergonomic and cost aspects. The use of virtual humans provides a better interpretation of the aircraft interior environment, making possible to simulate movements and passenger comfort aspects. The importance of this study becomes evident through the necessity of the aircraft manufacturer of predicting human behavior during all the flight phases. This text also aims to present the difficult...

  14. Escorting commercial aircraft to reduce the MANPAD threat

    Science.gov (United States)

    Hock, Nicholas; Richardson, M. A.; Butters, B.; Walmsley, R.; Ayling, R.; Taylor, B.

    2005-11-01

    This paper studies the Man-Portable Air Defence System (MANPADS) threat against large commercial aircraft using flight profile analysis, engagement modelling and simulation. Non-countermeasure equipped commercial aircraft are at risk during approach and departure due to the large areas around airports that would need to be secured to prevent the use of highly portable and concealable MANPADs. A software model (CounterSim) has been developed and was used to simulate an SA-7b and large commercial aircraft engagement. The results of this simulation have found that the threat was lessened when a escort fighter aircraft is flown in the 'Centreline Low' position, or 25 m rearward from the large aircraft and 15 m lower, similar to the Air-to-Air refuelling position. In the model a large aircraft on approach had a 50% chance of being hit or having a near miss (within 20m) whereas escorted by a countermeasure equipped F-16 in the 'Centerline Low' position, this was reduced to only 14%. Departure is a particularly vulnerable time for large aircraft due to slow climb rates and the inability to fly evasive manoeuvres. The 'Centreline Low' escorted departure greatly reduced the threat to 16% hit or near miss from 62% for an unescorted heavy aircraft. Overall the CounterSim modelling has showed that escorting a civilian aircraft on approach and departure can reduce the MANPAD threat by 3 to 4 times.

  15. [A Handling Qualities Metric for Damaged Aircraft

    Science.gov (United States)

    Cogan, Bruce; Hayes, Peggy

    2009-01-01

    In recent flight tests of F-15 Intelligent Flight Control System (IFCS), software simulated aircraft control surface failures were inserted to evaluate the IFCS adaptive systems. The failure commanded the left stabilator to a fixed position. The adaptive system uses a neural network that is designed to change control law gains, in the event of damage (real or simulated), that allows the aircraft to fly as it had before the damage. The performance of the adaptive system was assessed in terms of its ability to re-establish good onboard model tracking and its ability to decouple roll and pitch response.

  16. Small unmanned aircraft ballistic impact speed

    DEFF Research Database (Denmark)

    La Cour-Harbo, Anders

    2018-01-01

    A study of how smaller unmanned aircraft will fall in case of failure. The aim is to determine the impact speed of a drone givens its general shape and aerodynamic behavior. This will include both CFD simulations and real world test of ballistic drops of smaller drones.......A study of how smaller unmanned aircraft will fall in case of failure. The aim is to determine the impact speed of a drone givens its general shape and aerodynamic behavior. This will include both CFD simulations and real world test of ballistic drops of smaller drones....

  17. Role of charged lipids in membrane structures — Insight given by simulations

    DEFF Research Database (Denmark)

    Pöyry, Sanja; Vattulainen, Ilpo

    2016-01-01

    such as phosphatidylinositols and phosphatidylserines are involved in several examples of such effects. Molecular dynamics simulations have proved an invaluable tool in exploring these aspects. This so-called computational microscope can provide both complementing explanations for the experimental results and guide experiments...... to fruitful directions. In this paper, we review studies that have utilized molecular dynamics simulations to unravel the roles of charged lipids in membrane structures. We focus on lipids as active constituents of the membranes, affecting both general membrane properties as well as non-lipid membrane...

  18. The Role of Ultrasound Simulation in Obstetrics and Gynecology Training: A UK Trainees' Perspective.

    Science.gov (United States)

    Patel, Hersha; Chandrasekaran, Dhivya; Myriokefalitaki, Eva; Gebeh, Alpha; Jones, Kate; Jeve, Yadava B

    2016-10-01

    Ultrasonography is a core skill required by all obstetrics and gynecology trainees; however, training opportunities in clinical ultrasound are declining. Simulation ultrasound training has been proposed as a strategy to overcome this.The study aims were to determine the current availability of clinical and simulation ultrasound training in obstetrics and gynecology in the United Kingdom and to explore the trainees' perspective on the role of ultrasound simulation. All obstetrics and gynecology trainees within the East Midlands Local Education Training Board in the United Kingdom were asked to complete an anonymous web-based survey in July 2014. Of 140 trainees, 70 (50%) responded to the survey, and 69% reported rarely having dedicated clinical ultrasound sessions. Fifty percent had failed to achieve ultrasound competencies required for their stage of training, and 83% felt that the pressures of service provision limited their exposure to clinical ultrasound.Seventy-three percent of the trainees considered ultrasound simulation to be an essential component of training, and 69% agreed that it would help improve their clinical skills. Only 50% had access to an ultrasound simulator. Seventy-seven percent of the trainees thought that it would be useful to have ultrasound simulation integrated into training. Trainees are struggling to achieve minimal ultrasound competences with clinical ultrasound training alone. They believe that ultrasound simulation will shorten the learning curve and improve their clinical skills and knowledge. Despite the cost implications of simulation training, we propose that consideration is given to formal integration of ultrasound simulation into the curriculum as a possible way forward.

  19. 自行高炮模拟仿真实验平台设计与实现%Design and Realization of Simulation Experimental Platform for Self-propelled Anti-aircraft Gun

    Institute of Scientific and Technical Information of China (English)

    寇超; 孙书鹰; 王春平; 付强

    2011-01-01

    自行高炮模拟仿真实验平台可应用于火控原理教学和装备科研等场合.该实验平台以某型高炮构建解算模型,采用实物和半实物仿真的方法,以实际车体模型为运动载体,集成了导航、姿态测量系统、目标探测系统和武器系统的实体模型,在仿真火控计算机的控制下,可实现目标搜索、截获、电视自动跟踪、目标运动参数求取和射击诸元计算与输出等功能,同时,可处理车体姿态信息,实现瞄准线和武器线的稳定.该平台运动载体可以自动驾驶或遥控驾驶,配合仿真道路模拟车体姿态的变化,可以仿真短停射击和行进间射击等战术动作.%The simulation experimental platform for Self-propelled Anti-Aircraft Gun is used in teaching of fire control theory and studying of equipment. Using physical and semi-physical simulation, the fire control calculation model of the experimental platform is constructed according to a certain type of anti-aircraft gun. By taking real carbody as carrier, it integrates navigation, attitude measurement system, target detect system and physical model of weapon system. By controling of the simulation fire control computer, it can achieve the function of target detecting, intercepting and capturing, TV autotracking, getparms target movement and firing data calculation. What' s more, it deals with the information of carbody's attitude, realizes the sight line and weapon line stabilizing. With the simulation way to change carbody's attitude, the platform carrier can drive automatically or by controlling of remote-control unit, for simulating tactical action such as firing in short stop and traveling.

  20. Survival analysis of aging aircraft

    Science.gov (United States)

    Benavides, Samuel

    This study pushes systems engineering of aging aircraft beyond the boundaries of empirical and deterministic modeling by making a sharp break with the traditional laboratory-derived corrosion prediction algorithms that have shrouded real-world failures of aircraft structure. At the heart of this problem is the aeronautical industry's inability to be forthcoming in an accurate model that predicts corrosion failures in aircraft in spite of advances in corrosion algorithms or improvements in simulation and modeling. The struggle to develop accurate corrosion probabilistic models stems from a multitude of real-world interacting variables that synergistically influence corrosion in convoluted and complex ways. This dissertation, in essence, offers a statistical framework for the analysis of structural airframe corrosion failure by utilizing real-world data while considering the effects of interacting corrosion variables. This study injects realism into corrosion failures of aging aircraft systems by accomplishing four major goals related to the conceptual and methodological framework of corrosion modeling. First, this work connects corrosion modeling from the traditional, laboratory derived algorithms to corrosion failures in actual operating aircraft. This work augments physics-based modeling by examining the many confounding and interacting variables, such as environmental, geographical and operational, that impact failure of airframe structure. Examined through the lens of censored failure data from aircraft flying in a maritime environment, this study enhances the understanding between the triad of the theoretical, laboratory and real-world corrosion. Secondly, this study explores the importation and successful application of an advanced biomedical statistical tool---survival analysis---to model censored corrosion failure data. This well-grounded statistical methodology is inverted from a methodology that analyzes survival to one that examines failures. Third, this

  1. The Role of Computer Simulation in Nanoporous Metals—A Review

    Directory of Open Access Journals (Sweden)

    Re Xia

    2015-08-01

    Full Text Available Nanoporous metals (NPMs have proven to be all-round candidates in versatile and diverse applications. In this decade, interest has grown in the fabrication, characterization and applications of these intriguing materials. Most existing reviews focus on the experimental and theoretical works rather than the numerical simulation. Actually, with numerous experiments and theory analysis, studies based on computer simulation, which may model complex microstructure in more realistic ways, play a key role in understanding and predicting the behaviors of NPMs. In this review, we present a comprehensive overview of the computer simulations of NPMs, which are prepared through chemical dealloying. Firstly, we summarize the various simulation approaches to preparation, processing, and the basic physical and chemical properties of NPMs. In this part, the emphasis is attached to works involving dealloying, coarsening and mechanical properties. Then, we conclude with the latest progress as well as the future challenges in simulation studies. We believe that highlighting the importance of simulations will help to better understand the properties of novel materials and help with new scientific research on these materials.

  2. The Role of Computer Simulation in Nanoporous Metals—A Review

    Science.gov (United States)

    Xia, Re; Wu, Run Ni; Liu, Yi Lun; Sun, Xiao Yu

    2015-01-01

    Nanoporous metals (NPMs) have proven to be all-round candidates in versatile and diverse applications. In this decade, interest has grown in the fabrication, characterization and applications of these intriguing materials. Most existing reviews focus on the experimental and theoretical works rather than the numerical simulation. Actually, with numerous experiments and theory analysis, studies based on computer simulation, which may model complex microstructure in more realistic ways, play a key role in understanding and predicting the behaviors of NPMs. In this review, we present a comprehensive overview of the computer simulations of NPMs, which are prepared through chemical dealloying. Firstly, we summarize the various simulation approaches to preparation, processing, and the basic physical and chemical properties of NPMs. In this part, the emphasis is attached to works involving dealloying, coarsening and mechanical properties. Then, we conclude with the latest progress as well as the future challenges in simulation studies. We believe that highlighting the importance of simulations will help to better understand the properties of novel materials and help with new scientific research on these materials. PMID:28793491

  3. Composite Bonded Joints’ Lifetime for Aircraft under Random Fatigue Loads

    Directory of Open Access Journals (Sweden)

    Wei Guo Shen

    2014-04-01

    Full Text Available In this present study, a lifetime prediction model of composite bonded joint in aircraft is developed based on variation of its elastic modulus under Random Fatigue Loads (RFL of aircraft and its approach is deduced by Miner linear damage accumulated theory. Considering some assumptions, this prediction model is conservative for aircraft engineering industry. Finally, simulation approach and analysis is developed and done for verification of deduction models. As a precondition, some assumptions are defined for simulation and verification. From simulating results, we can give a conclusion that models are properly accuracy for further study and engineering application.

  4. On the Importance of Nonlinear Aeroelasticity and Energy Efficiency in Design of Flying Wing Aircraft

    Directory of Open Access Journals (Sweden)

    Pezhman Mardanpour

    2015-01-01

    Full Text Available Energy efficiency plays important role in aeroelastic design of flying wing aircraft and may be attained by use of lightweight structures as well as solar energy. NATASHA (Nonlinear Aeroelastic Trim And Stability of HALE Aircraft is a newly developed computer program which uses a nonlinear composite beam theory that eliminates the difficulties in aeroelastic simulations of flexible high-aspect-ratio wings which undergoes large deformation, as well as the singularities due to finite rotations. NATASHA has shown that proper engine placement could significantly increase the aeroelastic flight envelope which typically leads to more flexible and lighter aircraft. The areas of minimum kinetic energy for the lower frequency modes are in accordance with the zones with maximum flutter speed and have the potential to save computational effort. Another aspect of energy efficiency for High Altitude, Long Endurance (HALE drones stems from needing to minimize energy consumption because of limitations on the source of energy, that is, solar power. NATASHA is capable of simulating the aeroelastic passive morphing maneuver (i.e., morphing without relying on actuators and at as near zero energy cost as possible of the aircraft so as the solar panels installed on the wing are in maximum exposure to sun during different time of the day.

  5. Developing technical expertise in emergency medicine--the role of simulation in procedural skill acquisition.

    Science.gov (United States)

    Wang, Ernest E; Quinones, Joshua; Fitch, Michael T; Dooley-Hash, Suzanne; Griswold-Theodorson, Sharon; Medzon, Ron; Korley, Frederick; Laack, Torrey; Robinett, Adam; Clay, Lamont

    2008-11-01

    Developing technical expertise in medical procedures is an integral component of emergency medicine (EM) practice and training. This article is the work of an expert panel composed of members from the Society for Academic Emergency Medicine (SAEM) Interest Group, the SAEM Technology in Medical Education Committee, and opinions derived from the May 2008 Academic Emergency Medicine Consensus Conference, "The Science of Simulation in Healthcare." The writing group reviewed the simulation literature on procedures germane to EM training, virtual reality training, and instructional learning theory as it pertains to skill acquisition and procedural skills decay. The authors discuss the role of simulation in teaching technical expertise, identify training conditions that lead to effective learning, and provide recommendations for future foci of research.

  6. Perception of aircraft Deviation Cues

    Science.gov (United States)

    Martin, Lynne; Azuma, Ronald; Fox, Jason; Verma, Savita; Lozito, Sandra

    2005-01-01

    To begin to address the need for new displays, required by a future airspace concept to support new roles that will be assigned to flight crews, a study of potentially informative display cues was undertaken. Two cues were tested on a simple plan display - aircraft trajectory and flight corridor. Of particular interest was the speed and accuracy with which participants could detect an aircraft deviating outside its flight corridor. Presence of the trajectory cue significantly reduced participant reaction time to a deviation while the flight corridor cue did not. Although non-significant, the flight corridor cue seemed to have a relationship with the accuracy of participants judgments rather than their speed. As this is the second of a series of studies, these issues will be addressed further in future studies.

  7. The organizational context of ethical dilemmas: a role-playing simulation for the intensive care unit.

    Science.gov (United States)

    Strosberg, M A

    2001-01-01

    The allocation of health care resources often requires decision makers to balance conflicting ethical principles. The resource-constrained intensive care unit (ICU) provides an ideal setting to study how decision makers go about their balancing act in a complex and dynamic environment. The author presents a role-playing simulation exercise which models ICU admission and discharge decision making. Designed for the class-room, the simulation engages a variety of ethical, managerial, and public policy issues including end-of-life decision making, triage, and rationing. The simulation is based on a sequence of scenarios or "decision rounds" delineating conditions in the ICU in terms of disposition of ICU patients, number of available ICU beds, prognoses of candidates for admission, and other physiological and organizational information. Students, playing the roles of attending physician, hospital administrator, nurse manager, triage officer, and ethics committee member, are challenged to reach consensus in the context of multiple power centers and conflicting goals. An organization theory perspective, incorporated into the simulation, provides insight on how decisions are actually made and stimulates discussion on how decision making might be improved.

  8. Simulation training for the frontline--realistic preparation for role 1 doctors.

    Science.gov (United States)

    Mercer, S J; Howell, M; Simpson, R

    2010-06-01

    Simulation in Healthcare is gaining popularity worldwide. Recently it has been decided that there should be a simulation component to pre-deployment training for doctors destined for Role 1. Little is known about the challenges, workload, case mix and non-technical issues that face medical personnel working out of a Forward Operating Base. To examine this further, a workshop was convened with subject matter experts and simulation trainers. Common themes identified were concerning pre-deployment issues, team working, evaluation prior to transfer, equipment, communication and specific clinical issues. Six scenarios were developed over the course of the day that included desired learning objectives in form of technical and nontechnical skills. There are many aspects of team resource management or non-technical skills already researched that can be transferred directly into a Role 1 healthcare setting. Simulation offers the chance to provide training in a safe and controlled environment and can potentially ensure specific defined learning outcomes are achieved. This article reports the first steps in the process of providing this new type of training and discusses the faculty requirements, the available methods of delivery and specific issues surrounding fidelity.

  9. Role-play simulations for climate change adaptation education and engagement

    Science.gov (United States)

    Rumore, Danya; Schenk, Todd; Susskind, Lawrence

    2016-08-01

    In order to effectively adapt to climate change, public officials and other stakeholders need to rapidly enhance their understanding of local risks and their ability to collaboratively and adaptively respond to them. We argue that science-based role-play simulation exercises -- a type of 'serious game' involving face-to-face mock decision-making -- have considerable potential as education and engagement tools for enhancing readiness to adapt. Prior research suggests role-play simulations and other serious games can foster public learning and encourage collective action in public policy-making contexts. However, the effectiveness of such exercises in the context of climate change adaptation education and engagement has heretofore been underexplored. We share results from two research projects that demonstrate the effectiveness of role-play simulations in cultivating climate change adaptation literacy, enhancing collaborative capacity and facilitating social learning. Based on our findings, we suggest such exercises should be more widely embraced as part of adaptation professionals' education and engagement toolkits.

  10. Blood flow simulation on a role for red blood cells in platelet adhesion

    Science.gov (United States)

    Shimizu, Kazuya; Sugiyama, Kazuyasu; Takagi, Shu

    2016-11-01

    Large-scale blood flow simulations were conducted and a role for red blood cells in platelet adhesion was discussed. The flow conditions and hematocrit values were set to the same as corresponding experiments, and the numerical results were compared with the measurements. Numerical results show the number of platelets adhered on the wall is increased with the increase in hematocrit values. The number of adhered platelets estimated from the simulation was approximately 28 (per 0.01 square millimeter per minute) for the hematocrit value of 20%. These results agree well with the experimental results qualitatively and quantitatively, which proves the validity of the present numerical model including the interaction between fluid and many elastic bodies and the modeling of platelet adhesion. Numerical simulation also reproduces the behavior of red blood cells in the blood flow and their role in platelet adhesion. Red blood cells deform to a flat shape and move towards channel center region. In contrast, platelets are pushed out and have many chances to contact with the wall. As a result, the large number of adhered platelets is observed as hematocrit values becomes high. This result indicates the presence of red blood cells plays a crucial role in platelet adhesion.

  11. 飞机除冰液地面除冰过程模型仿真与实验%Model Simulation and Experiment of Aircraft Deicing Process Using Deicing Fluids on Ground

    Institute of Scientific and Technical Information of China (English)

    陈斌; 王立文

    2012-01-01

    描述了飞机地面除冰过程相关参数和热量损耗关系,选择机翼表面温度和积冰厚度作为描述该过程的状态变量,基于热平衡理论建立了该过程的数学模型。通过仿真研究,得出飞机地面除冰过程除冰效率的变化规律:提高除冰液温度,除冰效率明显提高;如果除冰液温度恒定,一味地增大除冰液流量,除冰效率提高不明显。在飞机地面除冰环境模拟装置上进行了模型验证实验,实验和仿真结果趋势一致,表明所建模型与实际过程匹配,可以为后续飞机地面除冰过程装备参数优化奠定基础。%Several parameters and thermal consumption associated with the deicing process were described,and then the airfoil temperature and the ice thickness on the airfoil were chosen as state parameters to depict the deicing process.The deicing process model was established and simulated based on thermal balance.The simulation results reveal that the deicing efficient is enhanced obviously with a high deicing fluids temperature,but the enhancement degree is small if the deicing fluids flow rate is raised only with the temperature constant.Finally,an experiment was done based on an aircraft deicing simulation equipment.Experiment results are consistent with simulation result,which shows that the model has a good match with practical process.So this model could be as the base for the further research on the aircraft deicing process parameters optimization.

  12. Stochastic Methods for Aircraft Design

    Science.gov (United States)

    Pelz, Richard B.; Ogot, Madara

    1998-01-01

    The global stochastic optimization method, simulated annealing (SA), was adapted and applied to various problems in aircraft design. The research was aimed at overcoming the problem of finding an optimal design in a space with multiple minima and roughness ubiquitous to numerically generated nonlinear objective functions. SA was modified to reduce the number of objective function evaluations for an optimal design, historically the main criticism of stochastic methods. SA was applied to many CFD/MDO problems including: low sonic-boom bodies, minimum drag on supersonic fore-bodies, minimum drag on supersonic aeroelastic fore-bodies, minimum drag on HSCT aeroelastic wings, FLOPS preliminary design code, another preliminary aircraft design study with vortex lattice aerodynamics, HSR complete aircraft aerodynamics. In every case, SA provided a simple, robust and reliable optimization method which found optimal designs in order 100 objective function evaluations. Perhaps most importantly, from this academic/industrial project, technology has been successfully transferred; this method is the method of choice for optimization problems at Northrop Grumman.

  13. Cable Tensiometer for Aircraft

    Science.gov (United States)

    Nunnelee, Mark (Inventor)

    2008-01-01

    The invention is a cable tensiometer that can be used on aircraft for real-time, in-flight cable tension measurements. The invention can be used on any aircraft cables with high precision. The invention is extremely light-weight, hangs on the cable being tested and uses a dual bending beam design with a high mill-volt output to determine tension.

  14. 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.

  15. Numerical simulation on response and damage of nuclear containment under aircraft impact%飞机对核安全壳撞击破坏效应的数值模拟

    Institute of Scientific and Technical Information of China (English)

    张涛; 方秦; 吴昊; 龚自明

    2014-01-01

    To analyze the damage failure of the nuclear containment under the impact of large aircrafts, the refined finite element models of aircraft A320 and the Lingao nuclear containment were established. The process of the im-pact was simulated by using the commercial finite element software LS-DYNA. The results show that there are three noticeable peaks in the process, corresponding to the impact of the cockpit, engines and wings( fuel tank) respec-tively. The maximum peak load is mainly caused by the impact of the engines. Compared with other related litera-tures, the impact load-time curve is similar. But the time duration and the peak load are obviously different for the differences of the aircraft type, mass and impacting velocity. Under the take-off and landing velocity of 100 m/s, containment is seriously damaged and the impacting centre suffers localized perforation, very probably leading to nuclear leakage.%为了研究大型商用客机撞击核电站安全壳的破坏效应,通过建立精细化的空客A320以及岭澳核电站安全壳有限元模型,采用LS-DYNA软件对飞机撞击安全壳进行了数值模拟。分析结果表明:A320撞击力时程曲线出现3次明显的峰值,分别对应驾驶舱、引擎以及机翼(油箱)受撞击产生,其中引擎撞击导致最大峰值荷载。得到的撞击力时程曲线形状与已有研究结论相似,但因飞机型号、质量及撞击速度不同,撞击持续时间、峰值荷载大小及出现时刻存在明显差别。在飞机速度为100 m/s撞击下安全壳损伤严重,撞击中心发生局部穿透并很有可能引发核泄漏。

  16. Using Synthetic Kerosene in Civil Jet Aircraft

    NARCIS (Netherlands)

    Snijders, T.A.; Melkert, J.A.

    2008-01-01

    TU Delft in the Netherlands is performing research into the effects of the use of synthetic kerosene in aircraft. The research program consists of both desk research and tests. In the desk research gas turbine simulations will be combined with payload range performance calculations to show engine ef

  17. Nonlinear dynamics of a vectored thrust aircraft

    DEFF Research Database (Denmark)

    Sørensen, C.B; Mosekilde, Erik

    1996-01-01

    With realistic relations for the aerodynamic coefficients, numerical simulations are applied to study the longitudional dynamics of a thrust vectored aircraft. As function of the thrust magnitude and the thrust vectoring angle the equilibrium state exhibits two saddle-node bifurcations and three...

  18. Nonlinear dynamics of a vectored thrust aircraft

    DEFF Research Database (Denmark)

    Sørensen, C.B; Mosekilde, Erik

    1996-01-01

    With realistic relations for the aerodynamic coefficients, numerical simulations are applied to study the longitudional dynamics of a thrust vectored aircraft. As function of the thrust magnitude and the thrust vectoring angle the equilibrium state exhibits two saddle-node bifurcations and three ...

  19. Using Synthetic Kerosene in Civil Jet Aircraft

    NARCIS (Netherlands)

    Snijders, T.A.; Melkert, J.A.

    2008-01-01

    TU Delft in the Netherlands is performing research into the effects of the use of synthetic kerosene in aircraft. The research program consists of both desk research and tests. In the desk research gas turbine simulations will be combined with payload range performance calculations to show engine

  20. Aircraft Survivability: Susceptibility Reduction, Summer 2006

    Science.gov (United States)

    2006-01-01

    Next Frontier (Dr. Joel D. Williamsen and Dr. Jeffery R. Calcaterra) u The Modeling & Simulation Information Analysis Center (Mr. Phil L. Abold) u...Aircraft Safe from MANPADS (Ms. Linda Lou Crosby ) u Fragment-Target Flash Experiments for the Validation of the Fire Protection Model (FPM) (Dr. R. Reed

  1. Simulations

    CERN Document Server

    Ngada, N M

    2015-01-01

    The complexity and cost of building and running high-power electrical systems make the use of simulations unavoidable. The simulations available today provide great understanding about how systems really operate. This paper helps the reader to gain an insight into simulation in the field of power converters for particle accelerators. Starting with the definition and basic principles of simulation, two simulation types, as well as their leading tools, are presented: analog and numerical simulations. Some practical applications of each simulation type are also considered. The final conclusion then summarizes the main important items to keep in mind before opting for a simulation tool or before performing a simulation.

  2. Hierarchical Colored Timed Petri Nets for Maintenance Process Modeling of Civil Aircraft

    Institute of Scientific and Technical Information of China (English)

    FU Cheng-cheng; SUN You-chao; LU Zhong

    2008-01-01

    Civil aircraft maintenance process simulation model is an effective method for analyzing the maintainability of a civil aircraft. First, we present the Hierarchical Colored Timed Petri Nets for maintenance process modeling of civil aircraft. Then, we expound a general method of civil aircraft maintenance activities, determine the maintenance level for decomposition, and propose the methods of describing logic of relations between the maintenance activities based on Petri Net. Finally, a time Colored Petri multi-level network modeling and simulation procedures and steps are given with the maintenance example of the landing gear burst tire of a certain type of aircraft. The feasibility of the method is proved by the example.

  3. Integration of simulations and visualizations into classroom contexts through role playing

    Science.gov (United States)

    Moysey, S. M.

    2016-12-01

    While simulations create a novel way to engage students, the idea of numerical modeling may be overwhelming to a wide swath of students - particularly non-geoscience majors or those students early in their earth science education. Yet even for these students, simulations and visualizations remain a powerful way to explore concepts and take ownership over their learning. One approach to bring these tools into the classroom is to introduce them as a component of a larger role-playing activity. I present two specific examples of how I have done this within a general education course broadly focused on water resources sustainability. In the first example, we have created an online multi-player watershed management game where players make management decisions for their individual farms, which in turn set the parameters for a watershed-scale groundwater model that continuously runs in the background. Through the simulation students were able to influence the behavior of the environment and see feedbacks on their individual land within the game. Though the original intent was to focus student learning on the hydrologic aspects of the watershed behavior, I have found that the value of the simulation is actually in allowing students to become immersed in a way that enables deep conversations about topics ranging from environmental policy to social justice. The second example presents an overview of a role playing activity focused on a multi-party negotiation of water rights in the Klamath watershed. In this case each student takes on a different role in the negotiation (e.g., farmer, energy producer, government, environmental advocate, etc.) and is presented with a rich set of data tying environmental and economic factors to the operation of reservoirs. In this case the simulation model is very simple, i.e., a mass balance calculator that students use to predict the consequences of their management decisions. The simplicity of the simulator, however, allows for

  4. RCS Simulation

    Science.gov (United States)

    2005-05-01

    store config.) to be considered, Moving parts to be considered · Hybridisation of methods · Fast algorithms, new Aproaches · Geometry representations...Page 2 Military Aircraft Overview • Introduction • Methods ,Tools for mm-wave applications • Examples • Further requirements / developments Page 3...Flexible handling of Geometry · Parametrisation of Geometry Page 4 Military Aircraft Methods for RCS simulations •Fundamental subdivision between full

  5. Energy Conversion and Storage Requirements for Hybrid Electric Aircraft

    Science.gov (United States)

    Misra, Ajay

    2016-01-01

    Among various options for reducing greenhouse gases in future large commercial aircraft, hybrid electric option holds significant promise. In the hybrid electric aircraft concept, gas turbine engine is used in combination with an energy storage system to drive the fan that propels the aircraft, with gas turbine engine being used for certain segments of the flight cycle and energy storage system being used for other segments. The paper will provide an overview of various energy conversion and storage options for hybrid electric aircraft. Such options may include fuel cells, batteries, super capacitors, multifunctional structures with energy storage capability, thermoelectric, thermionic or a combination of any of these options. The energy conversion and storage requirements for hybrid electric aircraft will be presented. The role of materials in energy conversion and storage systems for hybrid electric aircraft will be discussed.

  6. Effect of emotionally complex roles on HIV-related simulated patients.

    Science.gov (United States)

    Triviño, Ximena; Ferrer, Lilian; Bernales, Margarita; Cianelli, Rosina; Moore, Philippa; Peragallo, Nilda

    2013-01-01

    Simulated patients (SPs) have participated successfully in nursing and medical education. The SPs portraying stressful situations may have psychological or physiological effects for several days after their performance; however, long-term effects have not been well documented in the literature. The purpose of this study is to investigate the impact of interpreting roles related to HIV among SPs. A qualitative descriptive approach was used for this study. Questionnaires with open-ended questions were conducted immediately after the interpretation of HIV-related roles and a year later by 10 SPs. In addition, a focus group was run a year later using a preestablished interview guide. As a result of direct content analysis, 2 major themes emerged: effects of interpreting roles relating to HIV and complexity of the roles. The findings of this study stress that interpreting an HIV-related role produces emotional, behavioral, and physical effects in SPs, at any stage during the training or performance, and has a long-term impact on their perception of their personal health and risk.

  7. Molecular Dynamics Simulations Illuminate the Role of Counterion Condensation in the Electrophoretic Transport of Homogalacturonans.

    Science.gov (United States)

    Irani, Amir H; Owen, Jessie L; Mercadante, Davide; Williams, Martin A K

    2017-02-13

    Homogalacturonans (HGs) are polysaccharide copolymers of galacturonic acid and its methylesterified counterpart. The inter- and intramolecular distributions of the methylesterifed residues are vital behavior-determining characteristics of a sample's structure, and much experimental effort has been directed to their measurement. While many techniques are able to measure the sample-averaged degree of methylesterification (DM), the measurement of inter- and intramolecular charge distributions are challenging. Here, molecular dynamics (MD) simulations are used to calculate the electrophoretic mobilities of HGs that have different amounts and distributions of charges placed along the backbone. The simulations are shown to capture experimental results well, even for low-DM samples that possess high charge densities. In addition, they illuminate the role that local counterion condensation can play in the determination of the electrophoretic mobility of heterogeneous blocky polyelectrolytes that cannot be adequately described by a single chain-averaged charge spacing.

  8. Simulating the Role of Stellar Rotation in the Spectroscopic Effects of Differential Limb Magnification

    CERN Document Server

    Stevens, Adam R H

    2013-01-01

    Finite-source effects of gravitationally microlensed stars have been well discussed in the literature, but the role that stellar rotation plays has been neglected. A differential magnification map applied to a differentially Doppler-shifted surface alters the profiles of absorption lines, compromising their ordinarily symmetric nature. Herein, we assess the degree to which this finite-source effect of differential limb magnification (DLM), in combination with stellar rotation, alters spectroscopically derived stellar properties. To achieve this, we simulated a grid of high-magnification microlensing events using synthetic spectra. Our analysis shows that rotation of the source generates differences in the measured equivalent widths of absorption lines supplementary to DLM alone, but only of the order of a few percent. Using the wings of H alpha from the same simulated data, we confirmed the result of Johnson et al. (2010) that DLM alters measurements of effective temperature by < 100 K for dwarf stars, whi...

  9. CID Aircraft slap-down

    Science.gov (United States)

    1984-01-01

    In this photograph the B-720 is seen during the moments of initial impact. The left wing is digging into the lakebed while the aircraft continues sliding towards wing openers. In 1984 NASA Dryden Flight Research Facility and the Federal Aviation Administration (FAA) teamed-up in a unique flight experiment called the Controlled Impact Demonstration (CID). The test involved crashing a Boeing 720 aircraft with four JT3C-7 engines burning a mixture of standard fuel with an additive, Anti-misting Kerosene (AMK), designed to supress fire. In a typical aircraft crash, fuel spilled from ruptured fuel tanks forms a fine mist that can be ignited by a number of sources at the crash site. In 1984 the NASA Dryden Flight Research Facility (after 1994 a full-fledged Center again) and the Federal Aviation Administration (FAA) teamed-up in a unique flight experiment called the Controlled Impact Demonstration (CID), to test crash a Boeing 720 aircraft using standard fuel with an additive designed to supress fire. The additive, FM-9, a high-molecular-weight long-chain polymer, when blended with Jet-A fuel had demonstrated the capability to inhibit ignition and flame propagation of the released fuel in simulated crash tests. This anti-misting kerosene (AMK) cannot be introduced directly into a gas turbine engine due to several possible problems such as clogging of filters. The AMK must be restored to almost Jet-A before being introduced into the engine for burning. This restoration is called 'degradation' and was accomplished on the B-720 using a device called a 'degrader.' Each of the four Pratt & Whitney JT3C-7 engines had a 'degrader' built and installed by General Electric (GE) to break down and return the AMK to near Jet-A quality. In addition to the AMK research the NASA Langley Research Center was involved in a structural loads measurement experiment, which included having instrumented dummies filling the seats in the passenger compartment. Before the final flight on December 1

  10. CID Aircraft slap-down

    Science.gov (United States)

    1984-01-01

    In this photograph the B-720 is seen during the moments of initial impact. The left wing is digging into the lakebed while the aircraft continues sliding towards wing openers. In 1984 NASA Dryden Flight Research Facility and the Federal Aviation Administration (FAA) teamed-up in a unique flight experiment called the Controlled Impact Demonstration (CID). The test involved crashing a Boeing 720 aircraft with four JT3C-7 engines burning a mixture of standard fuel with an additive, Anti-misting Kerosene (AMK), designed to supress fire. In a typical aircraft crash, fuel spilled from ruptured fuel tanks forms a fine mist that can be ignited by a number of sources at the crash site. In 1984 the NASA Dryden Flight Research Facility (after 1994 a full-fledged Center again) and the Federal Aviation Administration (FAA) teamed-up in a unique flight experiment called the Controlled Impact Demonstration (CID), to test crash a Boeing 720 aircraft using standard fuel with an additive designed to supress fire. The additive, FM-9, a high-molecular-weight long-chain polymer, when blended with Jet-A fuel had demonstrated the capability to inhibit ignition and flame propagation of the released fuel in simulated crash tests. This anti-misting kerosene (AMK) cannot be introduced directly into a gas turbine engine due to several possible problems such as clogging of filters. The AMK must be restored to almost Jet-A before being introduced into the engine for burning. This restoration is called 'degradation' and was accomplished on the B-720 using a device called a 'degrader.' Each of the four Pratt & Whitney JT3C-7 engines had a 'degrader' built and installed by General Electric (GE) to break down and return the AMK to near Jet-A quality. In addition to the AMK research the NASA Langley Research Center was involved in a structural loads measurement experiment, which included having instrumented dummies filling the seats in the passenger compartment. Before the final flight on December 1

  11. Tropospheric sampling with aircraft

    Energy Technology Data Exchange (ETDEWEB)

    Daum, P.H.; Springston, S.R.

    1991-03-01

    Aircraft constitute a unique environment which places stringent requirements on the instruments used to measure the concentrations of atmospheric trace gases and aerosols. Some of these requirements such as minimization of size, weight, and power consumption are general; others are specific to individual techniques. This review presents the basic principles and considerations governing the deployment of trace gas and aerosol instrumentation on an aircraft. An overview of common instruments illustrates these points and provides guidelines for designing and using instruments on aircraft-based measurement programs.

  12. 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 ...

  13. Lightning hazards to aircraft

    Science.gov (United States)

    Corn, P. B.

    1978-01-01

    Lightning hazards and, more generally, aircraft static electricity are discussed by a representative for the Air Force Flight Dynamics Laboratory. An overview of these atmospheric electricity hazards to aircraft and their systems is presented with emphasis on electrical and electronic subsystems. The discussion includes reviewing some of the characteristics of lightning and static electrification, trends in weather and lightning-related mishaps, some specific threat mechanisms and susceptible aircraft subsystems and some of the present technology gaps. A roadmap (flow chart) is presented to show the direction needed to address these problems.

  14. Serious Simulation Role-Playing Games for Transformative Climate Change Education: "World Climate" and "Future Climate"

    Science.gov (United States)

    Rooney-Varga, J. N.; Sterman, J.; Sawin, E.; Jones, A.; Merhi, H.; Hunt, C.

    2012-12-01

    Climate change, its mitigation, and adaption to its impacts are among the greatest challenges of our times. Despite the importance of societal decisions in determining climate change outcomes, flawed mental models about climate change remain widespread, are often deeply entrenched, and present significant barriers to understanding and decision-making around climate change. Here, we describe two simulation role-playing games that combine active, affective, and analytical learning to enable shifts of deeply held conceptions about climate change. The games, World Climate and Future Climate, use a state-of-the-art decision support simulation, C-ROADS (Climate Rapid Overview and Decision Support) to provide users with immediate feedback on the outcomes of their mitigation strategies at the national level, including global greenhouse gas (GHG) emissions and concentrations, mean temperature changes, sea level rise, and ocean acidification. C-ROADS outcomes are consistent with the atmosphere-ocean general circulation models (AOGCMS), such as those used by the IPCC, but runs in less than one second on ordinary laptops, providing immediate feedback to participants on the consequences of their proposed policies. Both World Climate and Future Climate role-playing games provide immersive, situated learning experiences that motivate active engagement with climate science and policy. In World Climate, participants play the role of United Nations climate treaty negotiators. Participant emissions reductions proposals are continually assessed through interactive exploration of the best available science through C-ROADS. Future Climate focuses on time delays in the climate and energy systems. Participants play the roles of three generations: today's policymakers, today's youth, and 'just born.' The game unfolds in three rounds 25 simulated years apart. In the first round, only today's policymakers make decisions; In the next round, the young become the policymakers and inherit the

  15. Modeling and Simulation Approaches for Cardiovascular Function and Their Role in Safety Assessment.

    Science.gov (United States)

    Collins, T A; Bergenholm, L; Abdulla, T; Yates, Jwt; Evans, N; Chappell, M J; Mettetal, J T

    2015-03-01

    Systems pharmacology modeling and pharmacokinetic-pharmacodynamic (PK/PD) analysis of drug-induced effects on cardiovascular (CV) function plays a crucial role in understanding the safety risk of new drugs. The aim of this review is to outline the current modeling and simulation (M&S) approaches to describe and translate drug-induced CV effects, with an emphasis on how this impacts drug safety assessment. Current limitations are highlighted and recommendations are made for future effort in this vital area of drug research.

  16. The Role of Haptics in Medical Training Simulators: A Survey of the State of the Art.

    Science.gov (United States)

    Coles, T R; Meglan, D; John, N W

    2011-01-01

    This review paper discusses the role of haptics within virtual medical training applications, particularly, where it can be used to aid a practitioner to learn and practice a task. The review summarizes aspects to be considered in the deployment of haptics technologies in medical training. First, both force/torque and tactile feedback hardware solutions that are currently produced commercially and in academia are reviewed, followed by the available haptics-related software and then an in-depth analysis of medical training simulations that include haptic feedback. The review is summarized with scrutiny of emerging technologies and discusses future directions in the field.

  17. Dynamical Conditions of Ice Supersaturation and Ice Nucleation in Convective Systems: A Comparative Analysis Between in Situ Aircraft Observations and WRF Simulations

    Science.gov (United States)

    D’Alessandro, John J.; Diao, Minghui; Wu, Chenglai; Liu, Xiaohong; Chen, Ming; Morrison, Hugh; Eidhammer, Trude; Jensen, Jorgen B.; Bansemer, Aaron; Zondlo, Mark A.; hide

    2017-01-01

    Occurrence frequency and dynamical conditions of ice supersaturation (ISS, where relative humidity with respect to ice (RHi) greater than 100%) are examined in the upper troposphere around convective activity. Comparisons are conducted between in situ airborne observations and the Weather Research and Forecasting model simulations using four double-moment microphysical schemes at temperatures less than or or equal to -40degdegC. All four schemes capture both clear-sky and in-cloud ISS conditions. However, the clear-sky (in-cloud) ISS conditions are completely (significantly) limited to the RHi thresholds of the Cooper parameterization. In all of the simulations, ISS occurrence frequencies are higher by approximately 3-4 orders of magnitude at higher updraft speeds (greater than 1 m s(exp -1) than those at the lower updraft speeds when ice water content (IWC) greater than 0.01 gm(exp -3), while observations show smaller differences up to approximately 1-2 orders of magnitude. The simulated ISS also occurs less frequently at weaker updrafts and downdrafts than observed. These results indicate that the simulations have a greater dependence on stronger updrafts to maintain/generate ISS at higher IWC. At lower IWC (less than or equal or 0.01 gm(exp -3), simulations unexpectedly show lower ISS frequencies at stronger updrafts. Overall, the Thompson aerosol-aware scheme has the closest magnitudes and frequencies of ISS greater than 20% to the observations, and the modified Morrison has the closest correlations between ISS frequencies and vertical velocity at higher IWC and number density. The Cooper parameterization often generates excessive ice crystals and therefore suppresses the frequency and magnitude of ISS, indicating that it should be initiated at higher ISS (e.g.,lees than or equal to 25%).

  18. 分布式驱动的变体飞行器仿真系统设计与实现%Designing and Realizing of Simulation System for the Distributed Driven Morphing Aircraft

    Institute of Scientific and Technical Information of China (English)

    文哲远; 陆宇平

    2012-01-01

    In connection with the hardware system of morphing wings composed by 20 agents, via integrating visual airfoil control, process communication and aerodynamic data access modules, and owing to the use of object - oriented software, a morphing flight simulation system on the basis of variable parameter model has been developed. This system.can communicate with the underlying hardware to achieve control, and can integrate target airfoil and aerodynamic parameters to provide for the flight simulation program in real - time. Meanwhile, it will show the deformation effect. The operation result manifests that this system can control the morphing wings effectively and fulfills flight simulation of morphing aircraft.%针对由20个智能体搭建而成的变形翼硬件系统,通过集成可视化的翼型控制、进程通信、气动数据存取等模块,使用面向对象软件开发研制了基于变参数模型的变体飞行器仿真系统.系统能够与底层硬件实现控制通信,并能实时综合目标翼型和气动参数提供给飞行仿真程序,同时能够显示变形效果.运行结果表明,系统能够有效完成变形翼控制和变体飞行器的飞行仿真.

  19. Unmanned aircraft systems as wingmen

    Science.gov (United States)

    Garcia, Richard; Barnes, Laura; Fields, MaryAnne

    2010-04-01

    This paper introduces a concept towards integrating manned and Unmanned Aircraft Systems (UASs) into a highly functional team though the design and implementation of 3-D distributed formation/flight control algorithms with the goal to act as wingmen for a manned aircraft. This method is designed to minimize user input for team control, dynamically modify formations as required, utilize standard operating formations to reduce pilot resistance to integration, and support splinter groups for surveillance and/or as safeguards between potential threats and manned vehicles. The proposed work coordinates UAS members by utilizing artificial potential functions whose values are based on the state of the unmanned and manned assets including the desired formation, obstacles, task assignments, and perceived intentions. The overall unmanned team geometry is controlled using weighted potential fields. Individual UAS utilize fuzzy logic controllers for stability and navigation as well as a fuzzy reasoning engine for flight path intention prediction. Approaches are demonstrated in simulation using the commercial simulator X-Plane and controllers designed in Matlab/Simulink. Experiments include trail and right echelon formations as well as splinter group surveillance.

  20. The roles of COMT val158met status and aviation expertise in flight simulator performance and cognitive ability.

    Science.gov (United States)

    Kennedy, Q; Taylor, J L; Noda, A; Adamson, M; Murphy, G M; Zeitzer, J M; Yesavage, J A

    2011-09-01

    The polymorphic variation in the val158met position of the catechol-O-methyltransferase (COMT) gene is associated with differences in executive performance, processing speed, and attention. The purpose of this study is: (1) replicate previous COMT val158met findings on cognitive performance; (2) determine whether COMT val158met effects extend to a real-world task, aircraft navigation performance in a flight simulator; and (3) determine if aviation expertise moderates any effect of COMT val158met status on flight simulator performance. One hundred seventy two pilots aged 41-69 years, who varied in level of aviation training and experience, completed flight simulator, cognitive, and genetic assessments. Results indicate that although no COMT effect was found for an overall measure of flight performance, a positive effect of the met allele was detected for two aspects of cognitive ability: executive functioning and working memory performance. Pilots with the met/met genotype benefited more from increased levels of expertise than other participants on a traffic avoidance measure, which is a component of flight simulator performance. These preliminary results indicate that COMT val158met polymorphic variation can affect a real-world task.

  1. 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.

  2. Aircraft electromagnetic compatibility

    Science.gov (United States)

    Clarke, Clifton A.; Larsen, William E.

    1987-06-01

    Illustrated are aircraft architecture, electromagnetic interference environments, electromagnetic compatibility protection techniques, program specifications, tasks, and verification and validation procedures. The environment of 400 Hz power, electrical transients, and radio frequency fields are portrayed and related to thresholds of avionics electronics. Five layers of protection for avionics are defined. Recognition is given to some present day electromagnetic compatibility weaknesses and issues which serve to reemphasize the importance of EMC verification of equipment and parts, and their ultimate EMC validation on the aircraft. Proven standards of grounding, bonding, shielding, wiring, and packaging are laid out to help provide a foundation for a comprehensive approach to successful future aircraft design and an understanding of cost effective EMC in an aircraft setting.

  3. 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.

  4. Initial Inductive Learning in a Complex Computer Simulated Environment: The Role of Metacognitive Skills and Intellectual Ability.

    Science.gov (United States)

    Veenman, M. V. J.; Prins, F. J.; Elshout, J. J.

    2002-01-01

    Discusses conceptual knowledge acquisition using computer simulation and describes a study of undergraduates that examined the role of metacognitive skillfulness and intellectual ability during initial inductive learning with a complex computer simulation. Results showed that metacognitive skillfulness was positively related to learning behavior…

  5. Automatic aircraft recognition

    Science.gov (United States)

    Hmam, Hatem; Kim, Jijoong

    2002-08-01

    Automatic aircraft recognition is very complex because of clutter, shadows, clouds, self-occlusion and degraded imaging conditions. This paper presents an aircraft recognition system, which assumes from the start that the image is possibly degraded, and implements a number of strategies to overcome edge fragmentation and distortion. The current vision system employs a bottom up approach, where recognition begins by locating image primitives (e.g., lines and corners), which are then combined in an incremental fashion into larger sets of line groupings using knowledge about aircraft, as viewed from a generic viewpoint. Knowledge about aircraft is represented in the form of whole/part shape description and the connectedness property, and is embedded in production rules, which primarily aim at finding instances of the aircraft parts in the image and checking the connectedness property between the parts. Once a match is found, a confidence score is assigned and as evidence in support of an aircraft interpretation is accumulated, the score is increased proportionally. Finally a selection of the resulting image interpretations with the highest scores, is subjected to competition tests, and only non-ambiguous interpretations are allowed to survive. Experimental results demonstrating the effectiveness of the current recognition system are given.

  6. Variations of Endocrine Hormones Concentrations in Tupaia belangeri under Simulated Seasonal Acclimatized: Role of Leptin Sensitivity

    Directory of Open Access Journals (Sweden)

    Zhu, Wan-long

    2013-04-01

    Full Text Available Seasonal variations in endocrine hormones concentrations are important for the survival of small mammals during acclimatization. In order to understand the role of leptin sensitivity on other endocrine hormones concentrations, we examined body mass, serum leptin level, serum insulin, tri-iodothyronine (T 3, thyroxine (T4 and thyroid stimulating hormone (TSH concentrations in Tupaia belangeri under seasonal acclimatized (The simulated temperature and photoperiod in winter: 5°C and SD, 8h:16h Light:Dark; the simulated temperature and photoperiod in summer: 30°C and SD, 16h:8h Light:Dark for 4 weeks. The results showed that body mass, serum leptin level, serum T3, T4 concentrations and T3/T4 showed significant variation, but serum insulin and TSH concentrations showed no variations between treatment group. There were positive correlation between serum leptin level and insulin, T4 concentrations, and were negative correlation between serum leptin level and body mass, T3 concentrations. However, no correlation was found between serum TSH concentrations and serum leptin level. The present results suggested T. belangeri overcome winter thermogenesis challenges by adjusting body mass and endocrine hormones concentrations. Furthermore, leptin may play an potential role in their body mass regulation in T. belangeri.

  7. View of QF-106 aircraft cockpit

    Science.gov (United States)

    1997-01-01

    View of the cockpit and instrument panel of the QF-106 airplane used in the Eclipse project. In 1997 and 1998, the Dryden Flight Research Center at Edwards, California, supported and hosted a Kelly Space & Technology, Inc. project called Eclipse, which sought to demonstrate the feasibility of a reusable tow-launch vehicle concept. The project goal was to successfully tow, inflight, a modified QF-106 delta-wing aircraft with an Air Force C-141A transport aircraft. This would demonstrate the possibility of towing and launching an actual launch vehicle from behind a tow plane. Dryden was the responsible test organization and had flight safety responsibility for the Eclipse project. Dryden provided engineering, instrumentation, simulation, modification, maintenance, range support, and research pilots for the test program. The Air Force Flight Test Center (AFFTC), Edwards, California, supplied the C-141A transport aircraft and crew and configured the aircraft as needed for the tests. The AFFTC also provided the concept and detail design and analysis as well as hardware for the tow system and QF-106 modifications. Dryden performed the modifications to convert the QF-106 drone into the piloted EXD-01 (Eclipse eXperimental Demonstrator-01) experimental aircraft. Kelly Space & Technology hoped to use the results gleaned from the tow test in developing a series of low-cost, reusable launch vehicles. These tests demonstrated the validity of towing a delta-wing aircraft having high wing loading, validated the tow simulation model, and demonstrated various operational procedures, such as ground processing of in-flight maneuvers and emergency abort scenarios.

  8. The role of packaging size on contamination rates during simulated presentation to a sterile field.

    Directory of Open Access Journals (Sweden)

    Tony Trier

    Full Text Available The objective of this study was to assess the impact of package size on the contact between medical devices and non-sterile surfaces (i.e. the hands of the practitioner and the outside of the package during aseptic presentation to a simulated sterile field. Rationale for this objective stems from the decades-long problem of hospital-acquired infections. This work approaches the problem from a unique perspective, namely packaging size.Randomized complete block design with subsampling.Research study conducted at professional conferences for surgical technologists and nursing professionals.Ninety-seven healthcare providers, primarily surgical technologists and nurses.Participants were gloved and asked to present the contents of six pouches of three different sizes to a simulated sterile field. The exterior of pouches and gloves of participants were coated with a simulated contaminant prior to each opening trial. After presentation to the simulated sterile field, the presence of the contaminant on package contents was recorded as indicative of contact with non-sterile surfaces and analyzed in a binary fashion using a generalized linear mixed model.Recruited subjects were 26-64 years of age (81 females, 16 males, with 2.5-44 years of professional experience. Results indicated a significant main effect of pouch size on contact rate of package contents (P = 0.0108, whereby larger pouches induced greater rates of contact than smaller pouches (estimates±SEM: 14.7±2.9% vs. 6.0±1.7%, respectively.This study utilized novel methodologies which simulate contamination in aseptic presentation. Results of this work indicate that increased contamination rates are associated with larger pouches when compared to smaller pouches. The results add to a growing body of research which investigate packaging's role in serving as a pathway for product contamination during aseptic presentation. Future work should investigate other packaging design factors (e

  9. The role of biological rates in the simulated warming effect on oceanic CO2 uptake

    Science.gov (United States)

    Cao, Long; Zhang, Han

    2017-05-01

    Marine biology plays an important role in the ocean carbon cycle. However, the effect of warming-induced changes in biological rates on oceanic CO2 uptake has been largely overlooked. We use an Earth system model of intermediate complexity to investigate the effect of temperature-induced changes in biological rates on oceanic uptake of atmospheric CO2 and compare it with the effects from warming-induced changes in CO2 solubility and ocean mixing and circulation. Under the representative CO2 concentration pathway RCP 8.5 and its extension, by year 2500, relative to the simulation without warming effect on the ocean carbon cycle, CO2-induced warming reduces cumulative oceanic CO2 uptake by 469 Pg C, of which about 20% is associated with the warming-induced change in marine biological rates. In our simulations, the bulk effect of biological-mediated changes on CO2 uptake is smaller than that mediated by changes in CO2 solubility and ocean mixing and circulation. However, warming-induced changes in individual biological rates, including phytoplankton growth, phytoplankton mortality, and detritus remineralization, are found to affect oceanic CO2 uptake by an amount greater than or comparable to that caused by changes in CO2 solubility and ocean physics. Our simulations, which include only a few temperature-dependent biological processes, demonstrate the important role of biological rates in the oceanic CO2 uptake. In reality, many more complicated biological processes are sensitive to temperature change, and their responses to warming could substantially affect oceanic uptake of atmospheric CO2.

  10. Merging Energy Policy Decision Support, Education, and Communication: The 'World Energy' Simulation Role-Playing Game

    Science.gov (United States)

    Rooney-varga, J. N.; Franck, T.; Jones, A.; Sterman, J.; Sawin, E.

    2013-12-01

    To meet international goals for climate change mitigation and adaptation, as well as energy access and equity, there is an urgent need to explore and define energy policy paths forward. Despite this need, students, citizens, and decision-makers often hold deeply flawed mental models of the energy and climate systems. Here we describe a simulation role-playing game, World Energy, that provides an immersive learning experience in which participants can create their own path forward for global energy policy and learn about the impact of their policy choices on carbon dioxide emissions, temperature rise, energy supply mix, energy prices, and energy demand. The game puts players in the decision-making roles of advisors to the United Nations Sustainable Energy for All Initiative (drawn from international leaders from industry, governments, intergovernmental organizations, and citizens groups) and, using a state-of-the-art decision-support simulator, asks them to negotiate a plan for global energy policy. We use the En-ROADS (Energy Rapid Overview and Decision Support) simulator, which runs on a laptop computer in <0.1 sec. En-ROADS enables users to specify many factors, including R&D-driven cost reductions in fossil fuel-based, renewable, or carbon-neutral energy technologies; taxes and subsidies for different energy sources; performance standards and energy efficiency; emissions prices; policies to address other greenhouse gas emissions (e.g., methane, nitrous oxide, chlorofluorocarbons, etc.); and assumptions about GDP and population. In World Energy, participants must balance climate change mitigation goals with equity, prices and access to energy, and the political feasibility of policies. Initial results indicate participants gain insights into the dynamics of the energy and climate systems and greater understanding of the potential impacts policies.

  11. Design and simulation on low pass filter for frequency measurement circuit of aircraft AC power system%飞机交流电源测频电路低通滤波器的设计与仿真

    Institute of Scientific and Technical Information of China (English)

    党媚

    2015-01-01

    This paper conducted fault location and causal analysis,and provided the solution for this problem of Ac power frequency measurement jump In the process of model development . A low pass filter apply to Aircraft Ac power system frequency measurement circuit are Designed,and it's characteristics are also be analyzed and calculated.The filter model is set up based on Simulink for simulation,the result shows that the method of filter design is effective.%针对型号研制过程中出现的交流电源频率测量出现跳变的问题,进行了故障定位和原因分析,并提出了解决方案。设计了适用于飞机交流电源系统频率测量电路的低通滤波器,对其特性进行了计算分析,并基于SIMULINK建立了滤波器的模型,进行了仿真验证,结果表明设计的滤波器是有效的。

  12. Roles Of Photographic And Electro-Optic Imaging Sensors In The Modern Reconnaissance Aircraft-Will Electro-Optics Replace Film?

    Science.gov (United States)

    Fisher, Ralph W.; Graham, John; Koper, Harry F.; Lapp, Henry S.; Roberts, Alfred; Tracy, Robert E.

    1983-08-01

    Fisher. On my left is Robert E. Tracy. Bob probably has the honor of being a senior member on this panel and he has been involved in reconnaissance, one way or another, since about 1939. He has some real first-hand experience in that he actually flew as an aerial photographer in B-47s and RB-36s. He's also a qualified image interpreter. Since 1969 he has been project engineer on one of our advanced strategic aircraft. He earned his BS degree at Southern Illinois University and his MSA at Cal State. He has also pursued advanced studies in recce intelligence and various CAI, DIA, USA and industrial schools. He's a certified photogrammetrist, and a co-inventor on a patent for a correlation system for multi-sensor re-connaissance vehicles. Also, he's a member of several national groups dealing with reconnaissance and intelligence. I have been told by some people who have known him for a long time this his approach doesn't always follow the mainline thinking. So he fits in real well with this group.

  13. Aerial Survey of Ames Research Center - Flight Simulation Complex' Flight simulators create an

    Science.gov (United States)

    1967-01-01

    Aerial Survey of Ames Research Center - Flight Simulation Complex' Flight simulators create an authentic aircraft environment by generating the appropriate physical cues that provide the sensations of flight.

  14. Eyewitness Testimony for a Simulated Juvenile Crime by Male and Female Criminals with Consistent or Inconsistent Gender-Role Characteristics

    Science.gov (United States)

    Shapiro, Lauren R.

    2009-01-01

    Eyewitness recall by 60 adolescents and 60 young adults in Experiment 1 and by 64 children and 63 preadolescents in Experiment 2 for a simulated theft in which gender-role characteristics and sex of criminal were manipulated (i.e., masculine male, feminine male, feminine female, masculine female) was investigated. Gender-role flexibility impacted…

  15. Eyewitness Testimony for a Simulated Juvenile Crime by Male and Female Criminals with Consistent or Inconsistent Gender-Role Characteristics

    Science.gov (United States)

    Shapiro, Lauren R.

    2009-01-01

    Eyewitness recall by 60 adolescents and 60 young adults in Experiment 1 and by 64 children and 63 preadolescents in Experiment 2 for a simulated theft in which gender-role characteristics and sex of criminal were manipulated (i.e., masculine male, feminine male, feminine female, masculine female) was investigated. Gender-role flexibility impacted…

  16. Diagnosing Faults in Electrical Power Systems of Spacecraft and Aircraft

    Data.gov (United States)

    National Aeronautics and Space Administration — Electrical power systems play a critical role in spacecraft and aircraft, and they exhibit a rich variety of failure modes. This paper discusses electrical power...

  17. Aerodynamic Analysis of Civil Aircraft Equipped with Winglet on Numerical Simulation%民机翼梢小翼气动特性数值模拟分析研究

    Institute of Scientific and Technical Information of China (English)

    蒋彪; 李杰

    2011-01-01

    A certain type of civil aircraft wing and body are equipped with two different forms of winglets - Fusion Winglet and tip- fence. The point- to- point patched multi- block technology was used to generate high quality grid by ICEM software. Three- dimensional time- dependent compressible Reynolds- averaged Navier- Stokes equations were solved with third- order upwind- biased flux- difference splitting method and approximate factorization method. The numerical simulation was adopted to obtain reasonable geometry parameters of two different winglets at cruise point. The result data indicates that both winglet has increased lift coefficient and decreased drag coefficient, compared with the original wing- body model. The fusion wing, let increased the lift to drag ratio by 9%, and the tip fence increased the lift to drag ratio by 6%. However, the advantage of wing-body equipped with tip-fence in moment characteristic is obvious.The conclusions have great engineering application value in the design of civil aircraft winglet.%针对某民机翼身组合体加装不同翼梢小翼--融合式翼梢小翼和翼尖涡扩散器进行对比分析.用软件ICEM生成原始翼身组合体及加装不同小翼的翼身组合体的点对点对接多块网格技术生成高质量的数值计算网格,运用Roe三阶迎风偏置通量差分裂方法和隐式近似因子分解方法求解雷诺平均N-S方程.对两种不同翼梢小翼在巡航点进行数值模拟,得到合理的翼稍小翼几何参数;对比升阻特性数据,两种翼梢小翼都可以提高升力系数,减少阻力系数.相对原始翼身组合体,融合式翼梢小翼升阻比增加9%,翼尖涡扩散器升阻比增加6%;但翼尖涡扩散器在力矩特性上有较大优势.所得结论对民用飞机翼稍小翼设计工作具有较大的工程应用价值.

  18. 大型民用飞机风挡鸟撞的适航分析与数值仿真%Airworthiness Analysis and Numerical Simulation of Bird Impact on Large Civil Aircraft Windshield

    Institute of Scientific and Technical Information of China (English)

    陈佳慧; 胡宇群; 陈川

    2016-01-01

    鸟撞一直都是航空安全的隐患,对此需要有相应的适航条款来表明民用飞机相关部件的抗鸟撞性能符合要求。针对风挡鸟撞问题现状,分析了目前民用飞机鸟撞适航验证的方法和手段,对比研究了不同鸟撞数值模型,通过计算机辅助设计软件建立了某型民用飞机风挡三维几何模型,采用显式非线性数值分析软件ANSYS/LS-DYNA进行风挡鸟撞过程的数值仿真分析,以期为大型民机风挡鸟撞适航验证提供更有效的方法和手段,提高适航验证工作效率,降低工作成本。%Bird strike is a major threat to aircraft windshields and need a certification requirement for a proven level of impact resistance. Apart from costly bird strike experiments, explicit numerical modeling techniques have been employed. This paper summarized the current airworthiness verification methods of bird strike,compared the different bird strike analysis models. With the help of Computer Aided Design software,established a three-dimensional geometric model of a certain type of civil aircraft windshield,and the simulation of the dynamic process of bird impacting windshield is run using the nonlinear explicit finite element code ANSYS/LS-DYNA. The solution of analysis presents the theoretical basis for the airworthi-ness certification methods of bird strike windshield,in hope of improving the efficiency of airworthiness ver-ification work and reducing the cost.

  19. Aircraft Design Analysis, CFD And Manufacturing

    Directory of Open Access Journals (Sweden)

    Haifa El-Sadi

    2016-09-01

    Full Text Available Aircraft design, manufacturing and CFD analysis as part of aerodynamic course, the students achieve sizing from a conceptual sketch, select the airfoil geometry and the tail geometry, calculate thrust to weight ratio and wing loading, use initial sizing and calculate the aerodynamic forces. The students design their aircraft based on the geometrical dimensions resulted from the calculations and use the model to build a prototype, test it in wind tunnel and achieve CFD analysis to be compared with the experimental results. The theory of aerodynamic is taught and applied as a project based. In this paper, the design process, aircraft manufacturing and CFD analysis are presented to show the effect of project based on student’s learning of aerodynamic course. This project based learning has improved and accelerated students understanding of aerodynamic concepts and involved students in a constructive exploration. The analysis of the aircraft resulted in a study that revolved around the lift and drag generation of this particular aircraft. As to determine the lift and drag forces generated by this plane, a model was created in Solidworks a 3-D model-rendering program. After this model was created it was 3-D printed in a reduced scale, and subjected to wind tunnel testing. The results from the wind tunnel lab experiment were recorded. For accuracy, the same 3-D model was then simulated using CFD simulation software within Solidworks and compared with the results from the wind tunnel test. The values derived from both the simulation and the wind tunnel tests were then compared with the theoretical calculations for further proof of accuracy.

  20. Delivery performance of conventional aircraft by terminal-area, time-based air traffic control: A real-time simulation evaluation

    Science.gov (United States)

    Credeur, Leonard; Houck, Jacob A.; Capron, William R.; Lohr, Gary W.

    1990-01-01

    A description and results are presented of a study to measure the performance and reaction of airline flight crews, in a full workload DC-9 cockpit, flying in a real-time simulation of an air traffic control (ATC) concept called Traffic Intelligence for the Management of Efficient Runway-scheduling (TIMER). Experimental objectives were to verify earlier fast-time TIMER time-delivery precision results and obtain data for the validation or refinement of existing computer models of pilot/airborne performance. Experimental data indicated a runway threshold, interarrival-time-error standard deviation in the range of 10.4 to 14.1 seconds. Other real-time system performance parameters measured include approach speeds, response time to controller turn instructions, bank angles employed, and ATC controller message delivery-time errors.

  1. Aircraft Operations Classification System

    Science.gov (United States)

    Harlow, Charles; Zhu, Weihong

    2001-01-01

    Accurate data is important in the aviation planning process. In this project we consider systems for measuring aircraft activity at airports. This would include determining the type of aircraft such as jet, helicopter, single engine, and multiengine propeller. Some of the issues involved in deploying technologies for monitoring aircraft operations are cost, reliability, and accuracy. In addition, the system must be field portable and acceptable at airports. A comparison of technologies was conducted and it was decided that an aircraft monitoring system should be based upon acoustic technology. A multimedia relational database was established for the study. The information contained in the database consists of airport information, runway information, acoustic records, photographic records, a description of the event (takeoff, landing), aircraft type, and environmental information. We extracted features from the time signal and the frequency content of the signal. A multi-layer feed-forward neural network was chosen as the classifier. Training and testing results were obtained. We were able to obtain classification results of over 90 percent for training and testing for takeoff events.

  2. 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).

  3. IDENTIFICATION OF AIRCRAFT HAZARDS

    Energy Technology Data Exchange (ETDEWEB)

    K.L. Ashley

    2005-03-23

    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).

  4. Swarms of UAVs and fighter aircraft

    Energy Technology Data Exchange (ETDEWEB)

    Trahan, M.W.; Wagner, J.S.; Stantz, K.M.; Gray, P.C.; Robinett, R.

    1998-11-01

    This paper describes a method of modeling swarms of UAVs and/or fighter aircraft using particle simulation concepts. Recent investigations into the use of genetic algorithms to design neural networks for the control of autonomous vehicles (i.e., robots) led to the examination of methods of simulating large collections of robots. This paper describes the successful implementation of a model of swarm dynamics using particle simulation concepts. Several examples of the complex behaviors achieved in a target/interceptor scenario are presented.

  5. MOLECULAR DYNAMICS SIMULATION OF THE ROLE OF DISLOCATIONS IN MICROCRACK HEALING

    Institute of Scientific and Technical Information of China (English)

    Li Shen; Gao Kewei; Qiao Lijie; Chu Wuyang; Zhou Fuxin

    2000-01-01

    The molecular dynamics method is used to simulate microcrack healing during heating or/and under compressive stress. A centre microcrack in Cu crystal would be sealed under compressive stress or by heating. The role of compressive stress and heating in crack healing was additive. During microcrack healing,dislocation generation and motion occurred. When there were pre-existing dislocations around the microcrack, the critical temperature or compressive stress necessary for microcrack healing would decrease, and, the higher the number of dislocations,the lower the critical temperature or compressive stress. The critical temperaturenecessary for microcrack healing depended upon the orientation of the crack plane.For example, the critical temperature for the crack along the (001) plane was the lowest, i.e. 770K.

  6. Insulin improves cardiac myocytes contractile function recovery in simulated ischemia-reperfusion: Key role of Akt

    Institute of Scientific and Technical Information of China (English)

    ZHANG Bo; ZHANG Haifeng; FAN Qian; MA Xinliang; GAO Feng

    2003-01-01

    The present study examined cardiac myocyte contractile and Ca2+ transient responses to insulin during simulated ischemia/reperfusion (I/R) and furtherinvestigated the role of protein kinase B (Akt) in the insulin- induced inotropic effect. Ventricular myocytes were enzymatically isolated from adult Sprague-Dawley rats and perfused with Tyrode solution while electrically field-stimulated. Simulated I/R was induced by perfusing the cells with chemical anoxic solution including sodium cyanide-sodium lactate for 15 min followed by reperfusion with normal oxygenated Tyrode solution with or without insulin. It is found that insulin only at concentration as high as 10 IU/L could increase cell shortening (16±5%, P < 0.05) in normal myocytes, whereas it concentration-dependently (0.01-10 IU/L) increased the contraction,the velocity of shortening/releng- theningand Ca2+ transient in I/R myocytes. In addition, insulin treatment (1 IU/L) increased Akt phosphorylation of I/R cardiomyocytes by 2.4-fold compared with that of the control (P < 0.01). Most importantly, pretreatment with LY 294002, a specific inhibitor of phosphatidylinositol 3′-kinase (PI3-kinase), significantly inhibited both Akt phosphorylation and the positive inotropic response to insulin in the I/R cardiomyocytes. These results suggest that insulin exerts direct positive inotropic effect by increasing Ca2+ transient of cardiomyocytes, which is enhanced in the pathological condition of I/R. Akt activation plays an important role in the insulin-induced improvement of myocyte contractile function following I/R.

  7. Obstacle avoidance and path planning for carrier aircraft launching

    Directory of Open Access Journals (Sweden)

    Wu Yu

    2015-06-01

    Full Text Available Launching safety and efficiency are important indexes to measure the fighting capacity of carrier. The study on path planning for taxi of carrier aircraft launching under actual deck environment is of great significance. In actual deck scheduling, manual command is applied to taxi of carrier aircraft, which has negative effects on the safety of staff and carrier aircraft launching. In consideration of both the safety and efficiency of carrier aircraft launching, the key elements of the problem are abstracted based on the analysis of deck environment, carrier aircraft maneuver performance and task requirements. According to the problem description, the mathematical model is established including various constraints. The carrier aircraft and the obstacles are reasonably simplified as circle and polygons respectively. What’s more, the proposed collision detection model reduces the calculations. Aimed at the features of model, the theory of model predictive control (MPC is applied to the path search. Then a dynamic weight heuristic function is designed and a dynamic multistep optimization algorithm is proposed. Taking the Nimitz-class aircraft carrier as an example, the paths from parking place to catapult are planned, which indicate the rationality of the model and the effectiveness of the algorithm by comparing the planning results under different simulation environments. The main contribution of research is the establishment of obstacle avoidance and path planning model. In addition, it provides the solution of model and technological foundations for comprehensive command and real-time decision-making of the carrier aircraft.

  8. THE ROLE OF MUSCLE SPINDLE IN MUSCLE ATROPHY INDUCED BY SIMULATED MICROGRAVITY

    Institute of Scientific and Technical Information of China (English)

    张红梅; 樊小力; 周继斌

    2003-01-01

    Objective To compare the cross-section area (CSA) and the immunoreactivity of conjugated-ubiquitin in soleus extrafusal and intrafusal fibers after simulated-microgravity and to demonstrate the role of muscle spindle in muscle atrophy induced by simulated microgravity. Methods The immunohistochemical technique (ABC) and image analysis were used to assess the conjugated-ubiquitin immunostaining and the cross -sectional area of intrafusal and extrafusal fibers of soleus in simulated-microgravity rats. Results ①Tail-suspension caused a progressive loss of soleus mass. Mean fiber CSA of extrafusal fibers were (7±2)%, (21±4)% and (32±7)% smaller after 3 days, 7 days and 14 days suspension, respectively. While the CAS of intrafusal fibers (bag + chain fibers) were (14±3)% (P<0.05), (30±7)% (P<0.01) and (44±10)% (P<0.01) smaller after 3 days, 7 days and 14 days suspension. ② The immunoreactivity of conjugated-ubiquitin both in extrafusal and intrafusal fibers increased after tail-suspension. The immunoreactivity of intrafusal fibers increased 1 day after suspension and reached the hightest level at 3 days after tail-suspension. The immunoreactivity of extrafusal fibers increased after 3 days suspension and reached the highest level after 7 days tail-suspension, which was lower than that in intrafusal fibers after 3 days tail-suspension. Conclusion These results suggest that soleus atrophy of intrafusal fibers caused by tail-suspension is earlier and more severe than that in extrafusal fibers.

  9. Reading fiction and reading minds: the role of simulation in the default network

    Science.gov (United States)

    Bricker, Andrew B.; Dodell-Feder, David; Mitchell, Jason P.

    2016-01-01

    Research in psychology has suggested that reading fiction can improve individuals’ social-cognitive abilities. Findings from neuroscience show that reading and social cognition both recruit the default network, a network which is known to support our capacity to simulate hypothetical scenes, spaces and mental states. The current research tests the hypothesis that fiction reading enhances social cognition because it serves to exercise the default subnetwork involved in theory of mind. While undergoing functional neuroimaging, participants read literary passages that differed along two dimensions: (i) vivid vs abstract and (ii) social vs non-social. Analyses revealed distinct subnetworks of the default network respond to the two dimensions of interest: the medial temporal lobe subnetwork responded preferentially to vivid passages, with or without social content; the dorsomedial prefrontal cortex (dmPFC) subnetwork responded preferentially to passages with social and abstract content. Analyses also demonstrated that participants who read fiction most often also showed the strongest social cognition performance. Finally, mediation analysis showed that activity in the dmPFC subnetwork in response to the social content mediated this relation, suggesting that the simulation of social content in fiction plays a role in fiction’s ability to enhance readers’ social cognition. PMID:26342221

  10. Reading fiction and reading minds: the role of simulation in the default network.

    Science.gov (United States)

    Tamir, Diana I; Bricker, Andrew B; Dodell-Feder, David; Mitchell, Jason P

    2016-02-01

    Research in psychology has suggested that reading fiction can improve individuals' social-cognitive abilities. Findings from neuroscience show that reading and social cognition both recruit the default network, a network which is known to support our capacity to simulate hypothetical scenes, spaces and mental states. The current research tests the hypothesis that fiction reading enhances social cognition because it serves to exercise the default subnetwork involved in theory of mind. While undergoing functional neuroimaging, participants read literary passages that differed along two dimensions: (i) vivid vs abstract and (ii) social vs non-social. Analyses revealed distinct subnetworks of the default network respond to the two dimensions of interest: the medial temporal lobe subnetwork responded preferentially to vivid passages, with or without social content; the dorsomedial prefrontal cortex (dmPFC) subnetwork responded preferentially to passages with social and abstract content. Analyses also demonstrated that participants who read fiction most often also showed the strongest social cognition performance. Finally, mediation analysis showed that activity in the dmPFC subnetwork in response to the social content mediated this relation, suggesting that the simulation of social content in fiction plays a role in fiction's ability to enhance readers' social cognition.

  11. Simulation of symmetric nuclei and the role of Pauli potential in binding energies

    Energy Technology Data Exchange (ETDEWEB)

    M. Angeles Perez-Garcia, K. Tsushima, A. Valcarce

    2009-05-01

    It is shown that the use of a density dependent effective Pauli potential together with a nucleon-nucleon interaction potential plays a crucial role to reproduce not only the binding energies but also the matter root mean square radii of medium mass range spin-isospin saturated nuclei. This study is performed with a semiclassical Monte Carlo many-body simulation within the context of a simplified nucleon-nucleon interaction to focus on the effect of the genuine correlations due to the fermionic nature of nucleons. The procedure obtained is rather robust and it does not depend on the detailed features of the nucleon-nucleon interaction. For nuclei below saturation the density dependence may be represented in terms either of the nucleon number, $A$, or the associated Fermi momenta. When testing the simulation procedure for idealized "infinite" symmetric nuclear matter within the corresponding range of densities, it turns out that finite size effects affect the Pauli potential strength parametrization in systems up to about 120 particles while remaining approximately stable for larger systems.

  12. 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.

  13. Bonded structure application for aircraft. Kokuki ni okeru secchaku gijutsu

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, O. (Japan Airlines Co. Ltd., Tokyo (Japan))

    1991-01-05

    Adhesives play an important role in a technology of the aircraft structure for which lightness and strength are required. The paper explains the present situation of bonding technology employed for aircraft, the honeycomb structure, production of composite materials and the related problems. Advantages and purposes of employing adhesives as substitutes for fasteners like screws, rivets, etc. are as follows: decreases in stress concentration, weight reduction, smoothing of surfaces, improvement of acoustic fatigue by adhesives flexibility, prevention of gas-liquid leakage. Epoxide adhesives are mainly used for aircraft. Together with tear straps, which are metal-metal bonded to the rear fuselage plate of aircraft, and waffle doublers, an aluminium honeycomb sandwich structure, whose weight is 1/7 of an aluminium plate same in rigidity, is used in such parts of aircraft as spoilers, outer plates of flaps, etc. The problem of the bonded structure is detachment. Therefore, how to prevent, discover and repair it is most important. 3 figs.

  14. The effects of aircraft design on STOL ride quality

    Science.gov (United States)

    Jones, C. R.; Jacobson, I. D.

    1975-01-01

    Effects of aircraft dynamic characteristics on passenger ride quality are investigated to determine ride-quality isocontours similar to aircraft handling-qualities contours. Measurements are made on a moving-base simulator while varying the aircraft short-period and Dutch Roll frequencies and dampings. Both pilot ratings and subjective ride-quality ratings are obtained during flight. Ride and handling qualities were found to be complementary for the Dutch Roll mode, but not for the short-period mode. Regions of optimal ride and handling qualities are defined for the short-period mode, and the effects of turbulence levels studied.

  15. Life Assessment and Life Extension of an Aircraft Wheel

    Directory of Open Access Journals (Sweden)

    M. Aghaie-Khafri

    2012-01-01

    Full Text Available The effect of heat treatment and shot peening on the fatigue life of an aluminum aircraft wheel was studied. The effect of residual stress and heat treatment on the fatigue of specimens was studied by means of fatigue testing, residual stress measurement, and fractography. Finite element simulation was used for life assessment and evaluation of the effect of surface treatments on the life extension of the aircraft wheel. The results obtained show that the operational life of the aircraft wheel extended by imposed compressive residual stress and aging treatment.

  16. Advanced Aircraft Material

    Directory of Open Access Journals (Sweden)

    Vivek Kumar Prince

    2013-06-01

    Full Text Available There has been long debate on “advanced aircraft material” from past decades & researchers too came out with lots of new advanced material like composites and different aluminum alloys. Now days a new advancement that is in great talk is third generation Aluminum-lithium alloy. Newest Aluminum-lithium alloys are found out to have low density, higher elastic modulus, greater stiffness, greater cryogenic toughness, high resistance to fatigue cracking and improved corrosion resistance properties over the earlier used aircraft material as mentioned in Table 3 [1-5]. Comparison had been made with nowadays used composite material and is found out to be more superior then that

  17. 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.

  18. Aircraft Fuel Systems Career Ladder.

    Science.gov (United States)

    1985-09-01

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

  19. Building A Flight Control System For A Modelled Aircraft

    OpenAIRE

    Garratt, Paul William; Rushton, Andrew; Yilmaz, Esat

    2004-01-01

    Abstract. We modelled an aircraft based on the Airbus A320 and constructed a synthesisable flight control system. The novel feature was the use of C and VHDL, Very High Speed Inte-grated Circuit Design Language, to allow the flight control system to reside in a Field Pro-grammable Gate Array in a model aircraft or an Uninhabited Aerial Vehicle. The simulator models axial, normal, transverse, pitch, roll and yaw movements. The flight control system has automatic manoeuvre envelope protection a...

  20. Aircraft measurements of wave cloud

    Directory of Open Access Journals (Sweden)

    Z. Cui

    2012-05-01

    Full Text Available In this paper, aircraft measurements are presented of liquid phase (ice-free wave clouds made at temperatures greater than −5 °C that formed over Scotland, UK. The horizontal variations of the vertical velocity across wave clouds display a distinct pattern. The maximum updraughts occur at the upshear flanks of the clouds and the strong downdraughts at the downshear flanks. The cloud droplet concentrations were a couple of hundreds per cubic centimetres, and the drops generally had a mean diameter between 15–45 μm. A small proportion of the drops were drizzle. A new definition of a mountain-wave cloud is given, based on the measurements presented here and previous studies. The results in this paper provide a case for future numerical simulation of wave cloud and the interaction between wave and clouds.

  1. Identifying tacit strategies in aircraft maneuvers

    Science.gov (United States)

    Lewis, Charles M.; Heidorn, P. B.

    1991-01-01

    Two machine-learning methods are presently used to characterize the avoidance strategies used by skilled pilots in simulated aircraft encounters, and a general framework for the characterization of the strategic components of skilled behavior via qualitative representation of situations and responses is presented. Descriptions of pilot maneuvers that were 'conceptually equivalent' were ascertained by a concept-learning algorithm in conjunction with a classifier system that employed a generic algorithm; satisficing and 'buggy' strategies were thereby revealed.

  2. Aircraft Emissions Characterization

    Science.gov (United States)

    1988-03-01

    sample from each trap through a heated (1500C) six-port valve ’ Carle Instruments Model 5621) and onto the analytical column. The coLoponents in each...Environmental Protection, Vol. II. Aircraft Engine Emissions, Int. Civil Aviation Organ., 1981. 7. Nebel , G. J., "Benzene in Auto Exhaust," J. Air Poll

  3. Robots for Aircraft Maintenance

    Science.gov (United States)

    1993-01-01

    Marshall Space Flight Center charged USBI (now Pratt & Whitney) with the task of developing an advanced stripping system based on hydroblasting to strip paint and thermal protection material from Space Shuttle solid rocket boosters. A robot, mounted on a transportable platform, controls the waterjet angle, water pressure and flow rate. This technology, now known as ARMS, has found commercial applications in the removal of coatings from jet engine components. The system is significantly faster than manual procedures and uses only minimal labor. Because the amount of "substrate" lost is minimal, the life of the component is extended. The need for toxic chemicals is reduced, as is waste disposal and human protection equipment. Users of the ARMS work cell include Delta Air Lines and the Air Force, which later contracted with USBI for development of a Large Aircraft Paint Stripping system (LARPS). LARPS' advantages are similar to ARMS, and it has enormous potential in military and civil aircraft maintenance. The technology may also be adapted to aircraft painting, aircraft inspection techniques and paint stripping of large objects like ships and railcars.

  4. Aircraft Oxygen Generation

    Science.gov (United States)

    2012-02-01

    aircraft use some form of on-board oxygen generation provided by one of two corporations that dominate this market . A review of safety incident data...manufacture of synthetic resins (e.g., Bakelite), and for 161 making dyestuffs, flavorings, perfumes , and other chemicals. Some are used as

  5. Aircraft Detection from VHR Images Based on Circle-Frequency Filter and Multilevel Features

    Science.gov (United States)

    Gao, Feng; Li, Bo

    2013-01-01

    Aircraft automatic detection from very high-resolution (VHR) images plays an important role in a wide variety of applications. This paper proposes a novel detector for aircraft detection from very high-resolution (VHR) remote sensing images. To accurately distinguish aircrafts from background, a circle-frequency filter (CF-filter) is used to extract the candidate locations of aircrafts from a large size image. A multi-level feature model is then employed to represent both local appearance and spatial layout of aircrafts by means of Robust Hue Descriptor and Histogram of Oriented Gradients. The experimental results demonstrate the superior performance of the proposed method. PMID:24163637

  6. Aircraft Detection from VHR Images Based on Circle-Frequency Filter and Multilevel Features

    Directory of Open Access Journals (Sweden)

    Feng Gao

    2013-01-01

    Full Text Available Aircraft automatic detection from very high-resolution (VHR images plays an important role in a wide variety of applications. This paper proposes a novel detector for aircraft detection from very high-resolution (VHR remote sensing images. To accurately distinguish aircrafts from background, a circle-frequency filter (CF-filter is used to extract the candidate locations of aircrafts from a large size image. A multi-level feature model is then employed to represent both local appearance and spatial layout of aircrafts by means of Robust Hue Descriptor and Histogram of Oriented Gradients. The experimental results demonstrate the superior performance of the proposed method.

  7. Do black ducks and wood ducks habituate to aircraft disturbance?

    Science.gov (United States)

    Conomy, J.T.; Dubovsky, J.A.; Collazo, J.A.; Fleming, W.J.

    1998-01-01

    Requests to increase military aircraft activity in some training facilities in the United States have raised the need to determine if waterfowl and other wildlife are adversely affected by aircraft disturbance. We hypothesized that habituation was a possible proximate factor influencing the low proportion of free-ranging ducks reacting to military aircraft activities in a training range in coastal North Carolina during winters 1991 and 1992. To test this hypothesis, we subjected captive, wild-strain American black ducks (Anas rubripes) and wood ducks (Aix sponsa) to actual and simulated activities of jet aircraft. In the first experiment, we placed black ducks in an enclosure near the center of aircraft activities on Piney Island, a military aircraft target range in coastal North Carolina. The proportion of times black ducks reacted (e.g., alert posture, fleeing response) to visual and auditory aircraft activity decreased from 38 to 6% during the first 17 days of confinement. Response rates remained stable at 5.8% thereafter. In the second experiment, black ducks and wood ducks were exposed to 6 different recordings of jet noise. The proportion of times black ducks reacted to noise decreased (P 0.05) in time-activity budgets of black ducks between pre-exposure to noise and 24 hr after first exposure. Unlike black ducks, wood duck responses to jet noise did not decrease uniformly among experimental groups following initial exposure to noise (P = 0.01). We conclude that initial exposure to aircraft noise elicits behavioral responses from black ducks and wood ducks. With continued exposure of aircraft noise, black ducks may become habituated. However, wood ducks did not exhibit the same pattern of response, suggesting that the ability of waterfowl to habituate to aircraft noise may be species specific.

  8. Distributed Air Traffic Control Simulator

    Directory of Open Access Journals (Sweden)

    R. Radovanović

    2013-06-01

    Full Text Available During initial training air traffic control students acquire theoretical knowledge in various fields including air traffic management, aircraft performance, air traffic control equipment and systems, navigation and others. This paper proposes a simulator and explains its use and features that allows students to gain a practical insight into their coursework in order to complement their training. The goal of the simulator is to realistically implement all the key functionalities needed to cover the topics that were presented in class. The simulator offers a user friendly, distributed, and multi-role environment that can be deployed on regular PCs. Moreover, this paper discusses and resolves some of the main conceptual and implementational issues that were faced during simulator development.

  9. Validation study of a virtual reality robotic simulator--role as an assessment tool?

    Science.gov (United States)

    Lee, Jason Y; Mucksavage, Phillip; Kerbl, David C; Huynh, Victor B; Etafy, Mohamed; McDougall, Elspeth M

    2012-03-01

    Virtual reality simulators are often used for surgical skill training since they facilitate deliberate practice in a controlled, low stakes environment. However, to be considered for assessment purposes rigorous construct and criterion validity must be demonstrated. We performed face, content, construct and concurrent validity testing of the dV-Trainer™ robotic surgical simulator. Urology residents, fellows and attending surgeons were enrolled in this institutional review board approved study. After a brief introduction to the dV-Trainer each subject completed 3 repetitions each of 4 virtual reality tasks on it, including pegboard ring transfer, matchboard object transfer, needle threading of rings, and the ring and rail task. One week later subjects completed 4 similar tasks using the da Vinci® robot. Subjects were assessed on total task time and total errors using the built-in scoring algorithm and manual scoring for the dV-Trainer and the da Vinci robot, respectively. Seven experienced and 13 novice robotic surgeons were included in the study. Experienced surgeons were defined by greater than 50 hours of clinical robotic console time. Of novice robotic surgeons 77% ranked the dV-Trainer as a realistic training platform and 71% of experienced robotic surgeons ranked it as useful for resident training. Experienced robotic surgeons outperformed novices in many dV-Trainer and da Vinci robot exercises, particularly in the number of errors. On pooled data analysis dV-Trainer total task time and total errors correlated with da Vinci robot total task time and total errors (p = 0.026 and 0.011, respectively). This study confirms the face, content, construct and concurrent validity of the dV-Trainer, which may have a potential role as an assessment tool. Copyright © 2012 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  10. Congestion Pricing for Aircraft Pushback Slot Allocation.

    Science.gov (United States)

    Liu, Lihua; Zhang, Yaping; Liu, Lan; Xing, Zhiwei

    2017-01-01

    In order to optimize aircraft pushback management during rush hour, aircraft pushback slot allocation based on congestion pricing is explored while considering monetary compensation based on the quality of the surface operations. First, the concept of the "external cost of surface congestion" is proposed, and a quantitative study on the external cost is performed. Then, an aircraft pushback slot allocation model for minimizing the total surface cost is established. An improved discrete differential evolution algorithm is also designed. Finally, a simulation is performed on Xinzheng International Airport using the proposed model. By comparing the pushback slot control strategy based on congestion pricing with other strategies, the advantages of the proposed model and algorithm are highlighted. In addition to reducing delays and optimizing the delay distribution, the model and algorithm are better suited for use for actual aircraft pushback management during rush hour. Further, it is also observed they do not result in significant increases in the surface cost. These results confirm the effectiveness and suitability of the proposed model and algorithm.

  11. Structural Health Monitoring of AN Aircraft Joint

    Science.gov (United States)

    Mickens, T.; Schulz, M.; Sundaresan, M.; Ghoshal, A.; Naser, A. S.; Reichmeider, R.

    2003-03-01

    A major concern with ageing aircraft is the deterioration of structural components in the form of fatigue cracks at fastener holes, loose rivets and debonding of joints. These faults in conjunction with corrosion can lead to multiple-site damage and pose a hazard to flight. Developing a simple vibration-based method of damage detection for monitoring ageing structures is considered in this paper. The method is intended to detect damage during operation of the vehicle before the damage can propagate and cause catastrophic failure of aircraft components. It is typical that only a limited number of sensors could be used on the structure and damage can occur anywhere on the surface or inside the structure. The research performed was to investigate use of the chirp vibration responses of an aircraft wing tip to detect, locate and approximately quantify damage. The technique uses four piezoelectric patches alternatively as actuators and sensors to send and receive vibration diagnostic signals.Loosening of selected screws simulated damage to the wing tip. The results obtained from the testing led to the concept of a sensor tape to detect damage at joints in an aircraft structure.

  12. Braking performance of aircraft tires

    Science.gov (United States)

    Agrawal, Satish K.

    This paper brings under one cover the subject of aircraft braking performance and a variety of related phenomena that lead to aircraft hydroplaning, overruns, and loss of directional control. Complex processes involving tire deformation, tire slipping, and fluid pressures in the tire-runway contact area develop the friction forces for retarding the aircraft; this paper describes the physics of these processes. The paper reviews the past and present research efforts and concludes that the most effective way to combat the hazards associated with aircraft landings and takeoffs on contaminated runways is by measuring and displaying in realtime the braking performance parameters in the aircraft cockpit.

  13. Environmental Influence on Automatic Landing Error of the Carrier-Borne Aircraft

    Directory of Open Access Journals (Sweden)

    Han Zhimin

    2013-03-01

    Full Text Available The aim of this study is to analyze the movement model of aircraft carrier and stern flow model under the influence of marine sport. Also, we focus on the influence of marine sports and aft flow on the landing error of the carrier-borne aircraft under the guidance of the automatic landing system in different sea state level by numerical simulation and calculation. The analysis result is meaningful to the aircraft carrier due to the fact that environmental factors have a great influence on the error of carrier-borne aircraft landing on aircraft carrier, especially; marine sports and aft flow always affect the movement of an aircraft carrier and landing process of carrier-borne aircraft.

  14. Dynamics and Adaptive Control for Stability Recovery of Damaged Aircraft

    Science.gov (United States)

    Nguyen, Nhan; Krishnakumar, Kalmanje; Kaneshige, John; Nespeca, Pascal

    2006-01-01

    This paper presents a recent study of a damaged generic transport model as part of a NASA research project to investigate adaptive control methods for stability recovery of damaged aircraft operating in off-nominal flight conditions under damage and or failures. Aerodynamic modeling of damage effects is performed using an aerodynamic code to assess changes in the stability and control derivatives of a generic transport aircraft. Certain types of damage such as damage to one of the wings or horizontal stabilizers can cause the aircraft to become asymmetric, thus resulting in a coupling between the longitudinal and lateral motions. Flight dynamics for a general asymmetric aircraft is derived to account for changes in the center of gravity that can compromise the stability of the damaged aircraft. An iterative trim analysis for the translational motion is developed to refine the trim procedure by accounting for the effects of the control surface deflection. A hybrid direct-indirect neural network, adaptive flight control is proposed as an adaptive law for stabilizing the rotational motion of the damaged aircraft. The indirect adaptation is designed to estimate the plant dynamics of the damaged aircraft in conjunction with the direct adaptation that computes the control augmentation. Two approaches are presented 1) an adaptive law derived from the Lyapunov stability theory to ensure that the signals are bounded, and 2) a recursive least-square method for parameter identification. A hardware-in-the-loop simulation is conducted and demonstrates the effectiveness of the direct neural network adaptive flight control in the stability recovery of the damaged aircraft. A preliminary simulation of the hybrid adaptive flight control has been performed and initial data have shown the effectiveness of the proposed hybrid approach. Future work will include further investigations and high-fidelity simulations of the proposed hybrid adaptive Bight control approach.

  15. Experimental and Numerical Investigation of the Dynamic Seat Comfort in Aircrafts

    Science.gov (United States)

    Ciloglu, Hakan

    This research focuses on the dynamic seat comfort in aircrafts specifically during takeoff, landing and cruise through turbulence flight conditions. The experiments are performed using a multi axis shaker table in the Automotive Centre of Excellence (ACE) at the University of Ontario Institute of Technology subjected to sample takeoff, landing and cruise vibration recordings obtained onboard of an actual flight. The input vibrations introduced to the aircraft seats during actual flight conditions and during the experiments in the ACE are compared and it is concluded that the given flight conditions were successfully replicated for the interest of this thesis. The experiments are conducted with two different aircraft seats, economy class and business class. Furthermore, to investigate the importance of seat cushion characteristics in addition to economy and business class seat cushions, three laboratory made cushions were included in the investigation as well. Moreover, the effect of passenger weight is also discussed by conducting the experiments with 1 and 2 identical dummies. It is concluded that static seat properties play a significant role in the comfort perception level as well as flight conditions. Among the three flight condition, landing appeared to be the most uncomfortable case comparing to takeoff and cruise. In addition to experimental work, a numerical study to simulate the flight conditions is undertaken with the initial work of CAD modelling. The simulated responses of the seat is partially matching with experimental results due to unknown parameters of the cushion and the connections of the aircraft seat that cannot be created in the CAD model due to unknown manufacturing processes.

  16. Aircraft Abnormal Conditions Detection, Identification, and Evaluation Using Innate and Adaptive Immune Systems Interaction

    Science.gov (United States)

    Al Azzawi, Dia

    Abnormal flight conditions play a major role in aircraft accidents frequently causing loss of control. To ensure aircraft operation safety in all situations, intelligent system monitoring and adaptation must rely on accurately detecting the presence of abnormal conditions as soon as they take place, identifying their root cause(s), estimating their nature and severity, and predicting their impact on the flight envelope. Due to the complexity and multidimensionality of the aircraft system under abnormal conditions, these requirements are extremely difficult to satisfy using existing analytical and/or statistical approaches. Moreover, current methodologies have addressed only isolated classes of abnormal conditions and a reduced number of aircraft dynamic parameters within a limited region of the flight envelope. This research effort aims at developing an integrated and comprehensive framework for the aircraft abnormal conditions detection, identification, and evaluation based on the artificial immune systems paradigm, which has the capability to address the complexity and multidimensionality issues related to aircraft systems. Within the proposed framework, a novel algorithm was developed for the abnormal conditions detection problem and extended to the abnormal conditions identification and evaluation. The algorithm and its extensions were inspired from the functionality of the biological dendritic cells (an important part of the innate immune system) and their interaction with the different components of the adaptive immune system. Immunity-based methodologies for re-assessing the flight envelope at post-failure and predicting the impact of the abnormal conditions on the performance and handling qualities are also proposed and investigated in this study. The generality of the approach makes it applicable to any system. Data for artificial immune system development were collected from flight tests of a supersonic research aircraft within a motion-based flight

  17. Observations of Cloud Top Entrainment Instability Induced by Aircraft Wake Downwash

    Science.gov (United States)

    Walcek, C. J.

    2012-12-01

    Aircraft produce considerable turbulence and generate 20-80 m/s downward velocity impulses immediately below the airframe and wings. This downward-propagating air produces turbulent vortices that descend 100-300 meters before dissipating. If an aircraft flies very close to the tops of stratiform clouds, it can induce mixing between cloudy air and clear air pushed into the cloud from above cloud top. Here we present photographs and evidence that aircraft flying close to the tops of stable stratiform clouds can trigger the release of cloud-top entrainment instability (CTEI). Negatively-buoyant air can be produced as warm air forced into a cloud from above cloud top mixes with colder cloudy air, inducing evaporation and further cooling below the cloud temperature, thus initiating turbulent downdrafts that can propagate the CTEI mechanism that ultimately dissipates and evaporates the top several hundred meters near cloud top. Photographs taken from observation chase planes flying 1-2 km above another aircraft flying very close to cloud top show 50-100 m wide swaths cleared within 3-4 seconds after fly-over, and growth rates of 2-3 m/s lateral to the flight track are observed. Ultimately "canal cloud" or "hole punch" features 2-3 km wide are generated in 20-30 minutes following the flyover from this mechanism. Here the mechanism of aircraft downwash is reviewed, CTEI is described, and evidence of the importance of evaporation and entrainment is provided from unpublished results from the late 1940s-era "project CIRRUS" and more recent images of hole-punch and canal-clouds. Since the propagation of this turbulent process occurs in turbulent filaments of mixtures of clear and cloudy air, modeling this process will require resolutions of less than several meters, yet require simulation domains several 1000s of meters wide. Similarly, measurements of dissipated cloud regions induced by aircraft would require resolutions of several meters or 10s of Hz to unambiguously

  18. Research and Design of Self-propelled Anti-aircraft Gun CGF Based on HLA%基于HLA的自行高炮CGF的研究与设计

    Institute of Scientific and Technical Information of China (English)

    王鹏; 朱元昌; 邸彦强; 毕博

    2011-01-01

    CGF是分布式交互作战仿真的重要支撑技术,在武器系统模拟训练平台中起着极其重要的作用.首先介绍了基于HLA框架实现自行高炮CGF的设计思想和原则,并结合自行高炮作战模拟训练过程,构建了基于HLA的自行高炮CGF体系结构和行为模型.在自行高炮CGF智能决策实现方面,对自行高炮CGF实体智能行为仿真的方法进行了理论探索,最后给出了自行高炮CGF系统的仿真实现方法和一个高炮CGF系统.对于以后基于HLA的自行高炮模拟训练系统中自行高炮CGF的开发具有很大参考价值.%CGF is an important support technalogy in the distributed interactive simulation and plays a very important role in the simulating training platform of the weapon system.A design thought and method to realize the self-propelled anti-aircraft gun CGF based on HLA frame are intraduced.The systematic structure and behaviour model of the self-propelled anti-aircraft gun CGF based on HLA are established in combination with the simulated training course of the self-propelled anti-aircraft gun.In the implement of anti-aircraft gun CGF behavior decision, the theoretic exploration on the method to simulate the artificial intellectual behavior of the self-propelled anti-aircraft gun CGF entity is performed.At last, the simulation implementation method of anti-aircraft gun CGF system and a prototype system of the anti-aircraft gun CGF are offered.The method has good referenced value for the development of anti-aircraft gun CGF in the self-propelled anti-aircraft gun simulation training system based an HLA.

  19. Potential Role of the Last Half Repeat in TAL Effectors Revealed by a Molecular Simulation Study

    Directory of Open Access Journals (Sweden)

    Hua Wan

    2016-01-01

    Full Text Available TAL effectors (TALEs contain a modular DNA-binding domain that is composed of tandem repeats. In all naturally occurring TALEs, the end of tandem repeats is invariantly a truncated half repeat. To investigate the potential role of the last half repeat in TALEs, we performed comparative molecular dynamics simulations for the crystal structure of DNA-bound TALE AvrBs3 lacking the last half repeat and its modeled structure having the last half repeat. The structural stability analysis indicates that the modeled system is more stable than the nonmodeled system. Based on the principle component analysis, it is found that the AvrBs3 increases its structural compactness in the presence of the last half repeat. The comparison of DNA groove parameters of the two systems implies that the last half repeat also causes the change of DNA major groove binding efficiency. The following calculation of hydrogen bond reveals that, by stabilizing the phosphate binding with DNA at the C-terminus, the last half repeat helps to adopt a compact conformation at the protein-DNA interface. It further mediates more contacts between TAL repeats and DNA nucleotide bases. Finally, we suggest that the last half repeat is required for the high-efficient recognition of DNA by TALE.

  20. Potential Role of the Last Half Repeat in TAL Effectors Revealed by a Molecular Simulation Study

    Science.gov (United States)

    Wan, Hua; Chang, Shan; Hu, Jian-ping; Tian, Xu-hong

    2016-01-01

    TAL effectors (TALEs) contain a modular DNA-binding domain that is composed of tandem repeats. In all naturally occurring TALEs, the end of tandem repeats is invariantly a truncated half repeat. To investigate the potential role of the last half repeat in TALEs, we performed comparative molecular dynamics simulations for the crystal structure of DNA-bound TALE AvrBs3 lacking the last half repeat and its modeled structure having the last half repeat. The structural stability analysis indicates that the modeled system is more stable than the nonmodeled system. Based on the principle component analysis, it is found that the AvrBs3 increases its structural compactness in the presence of the last half repeat. The comparison of DNA groove parameters of the two systems implies that the last half repeat also causes the change of DNA major groove binding efficiency. The following calculation of hydrogen bond reveals that, by stabilizing the phosphate binding with DNA at the C-terminus, the last half repeat helps to adopt a compact conformation at the protein-DNA interface. It further mediates more contacts between TAL repeats and DNA nucleotide bases. Finally, we suggest that the last half repeat is required for the high-efficient recognition of DNA by TALE. PMID:27803930

  1. Vision-aided Navigation for Autonomous Aircraft Based on Unscented Kalman Filter

    Directory of Open Access Journals (Sweden)

    Junwei Yu

    2013-02-01

    Full Text Available A vision-aided navigation system for autonomous aircraft is described in this paper. The vision navigation of the aircraft to the known scence is performed with a camera fixed on the aircraft. The location and pose of the aircraft are estimated with the corresponding control points which can be detected in the images captured. The control points are selected according their saliency and are tracked in sequential images based on Fourier-Melline transform. The simulation model of the aircraft dynamics and vision-aided navigation system based on Matlab/Simulink is built.The unscented Kalman filter is used to fuse the aircraft state information provided by the vision system and the inertial navigation system. Simulation results show that the vision-based navigation system provides satisfactory results of both accuracy and reliability.

  2. [The role of chemoreception in forming of Daphnia longispina sustainable population (the simulation experiments)].

    Science.gov (United States)

    Alekseev, V R; Kazantseva, T I

    2015-01-01

    Individual-based mathematical models may be considered a promising tool for studying the patterns of aquatic animals population development under conditions of exposure to various environmental factors including those ones that are difficult to measure directly. To test the hypotheses on the role of chemoreception in vital activity of aquatic invertebrates, we used the previously designed individual-based simulation model of a mass pelagic species, Daphnia longispina, population. The model describes a population as an ordered list of individuals with specific set of traits. For each individual, its energetic traits are calculated, also the probabilities of outcomes from different life situations are assigned or calculated. Included in the model are responses of adult individuals to two types of chemical signals: 1) diurnal vertical migrations from surface to hypolimnion when detecting fish cairomones; 2) active search for mature females by adult males via pheromones, effects of which grow stronger with water temperature raising. By comparison with previous versions of the model, introduction of these responses allowed to reproduce seasonal dynamics of the model population most closely to real dynamics of the prototype population. Consecutive, and then joint switching off of the ability to detect chemical signals made it possible to obtain a quantitative estimate of their role in population dynamics optimization and to determine limiting levels of predators, both vertebrate and invertebrate, pressure on organisms lacking the ability to use chemotaxis. In particular, it was found out that, in the model population, the size of water flea spring generation is determined by the amount of overwintered dormant eggs which increases as a result of active search for mature females due to chemoreception. The size of summer-autumn generation is practically independent of initial numbers and is determined by living conditions during the season, first of all by the factor of

  3. Examining the Role of N2O5 Hydrolysis and ClNO2 Production Over the Northeast United States: Results from WINTER 2015 Aircraft Campaign

    Science.gov (United States)

    Haskins, J.; Jaegle, L.; Thornton, J. A.; Shah, V.; Lopez-Hilfiker, F.; Lee, B. H.; Fibiger, D. L.; McDuffie, E.; Brown, S. S.; Jimenez, J. L.; Weber, R. J.; Dibb, J. E.; Day, D. A.; Holloway, J. S.; Fiddler, M. N.; Campuzano Jost, P.; Schroder, J. C.; Sullivan, A.; Veres, P. R.; Green, J. R.

    2015-12-01

    The heterogeneous uptake of N2O5 on liquid aerosol particles plays a critical role in regulating tropospheric reactive nitrogen (NOx) availability, particle nitrate loadings, and halogen activity, which, in turn, have downwind effects on oxidant availability and ozone production. However, parameterizations of this process in regional and global models remain relatively untested. Measurements taken during the 2015 Wintertime Investigation of Transportation, Emissions, & Reactivity (WINTER) allow both empirical and theoretical calculations of the N2O5 reactive uptake coefficient (γ) and ClNO2 yield (Y) during 13 winter flights over the eastern US. We use observations of gas and particle composition as inputs to the offline thermodynamic equilibrium models, ISORROPIA II and AIM, to generate outputs of particulate aqueous phase concentrations of NO3-(aq), Cl-(aq), and H2O(l) . These outputs are used to theoretically calculate γ (N2O5) and Y(ClNO2), using the parameterizations described in Bertram & Thornton, 2009. The calculated values are then compared to the empirical counterparts to assess the validity of the parameterization's representation of temperature, humidity, and composition dependences. The updated parameterization is then used in the online GEOS-Chem chemical transport model to examine the role of wintertime multiphase chemistry in controlling the regional distribution and export of NOx and Cl-atom source downwind of the northeast United States.

  4. In Search of Consensus: Role Versus Belief Systems in Bureaucratic Bargaining. An American Foreign Policy Simulation (AFPS).

    Science.gov (United States)

    Hobbs, Heidi H.; Moreno, Dario V.

    Reported are results from two runs of the simulation "Bureaucratic Bargaining," developed to help students understand the inherent tension between roles and belief systems in American foreign policy decision making. To determine their belief systems, 165 students enrolled in an introductory international relations course were tested with…

  5. Simulation

    DEFF Research Database (Denmark)

    Gould, Derek A; Chalmers, Nicholas; Johnson, Sheena J

    2012-01-01

    Recognition of the many limitations of traditional apprenticeship training is driving new approaches to learning medical procedural skills. Among simulation technologies and methods available today, computer-based systems are topical and bring the benefits of automated, repeatable, and reliable p...... performance assessments. Human factors research is central to simulator model development that is relevant to real-world imaging-guided interventional tasks and to the credentialing programs in which it would be used.......Recognition of the many limitations of traditional apprenticeship training is driving new approaches to learning medical procedural skills. Among simulation technologies and methods available today, computer-based systems are topical and bring the benefits of automated, repeatable, and reliable...

  6. Unified Theory for Aircraft Handling Qualities and Adverse Aircraft-Pilot Coupling

    Science.gov (United States)

    Hess, R. A.

    1997-01-01

    A unified theory for aircraft handling qualities and adverse aircraft-pilot coupling or pilot-induced oscillations is introduced. The theory is based on a structural model of the human pilot. A methodology is presented for the prediction of (1) handling qualities levels; (2) pilot-induced oscillation rating levels; and (3) a frequency range in which pilot-induced oscillations are likely to occur. Although the dynamics of the force-feel system of the cockpit inceptor is included, the methodology will not account for effects attributable to control sensitivity and is limited to single-axis tasks and, at present, to linear vehicle models. The theory is derived from the feedback topology of the structural model and an examination of flight test results for 32 aircraft configurations simulated by the U.S. Air Force/CALSPAN NT-33A and Total In-Flight Simulator variable stability aircraft. An extension to nonlinear vehicle dynamics such as that encountered with actuator saturation is discussed.

  7. Simulation

    CERN Document Server

    Ross, Sheldon

    2006-01-01

    Ross's Simulation, Fourth Edition introduces aspiring and practicing actuaries, engineers, computer scientists and others to the practical aspects of constructing computerized simulation studies to analyze and interpret real phenomena. Readers learn to apply results of these analyses to problems in a wide variety of fields to obtain effective, accurate solutions and make predictions about future outcomes. This text explains how a computer can be used to generate random numbers, and how to use these random numbers to generate the behavior of a stochastic model over time. It presents the statist

  8. C-MAPSS Aircraft Engine Simulator Data

    Data.gov (United States)

    National Aeronautics and Space Administration — SPECIAL NOTE: C-MAPSS and C-MAPSS40K ARE CURRENTLY UNAVAILABLE FOR DOWNLOAD. Glenn Research Center management is reviewing the availability requirements for these...

  9. Evaluation of the doses to aircrew members by considering the aircraft structures

    Science.gov (United States)

    Battistoni, G.; Ferrari, A.; Pelliccioni, M.; Villari, R.

    A mathematical model of an aircraft has been developed with the aim to investigate the influence of the aircraft structures and contents on the exposure of aircrew and passengers to the galactic component of cosmic rays. The irradiation of the mathematical model in the cosmic ray environment has been simulated using the Monte Carlo transport code FLUKA. Effective dose and ambient dose equivalent rates have been determined inside the aircraft at several locations along the fuselage at typical civil aviation altitudes.

  10. Numerical and Experimental Investigation of the Structural Behavior during Aircraft Emergency Landing on Water

    OpenAIRE

    Siemann, Martin

    2016-01-01

    Although occurring infrequent, the emergency landing of aircraft on water constitutes a crucial facet within aviation safety and, hence, it engages aircraft manufacturers within design and certification processes. Currently employed methods to analyze ditching comprise experimental testing, comparison with already ditching-certified aircraft designs, and semi-analytical as well as uncoupled numerical simulations. Since these means comprise several drawbacks and limitations, there is the motiv...

  11. Environmental Damage and Environmental Adaptability of the Aircraft in Marine Atmosphere

    Directory of Open Access Journals (Sweden)

    LUO Chen

    2016-06-01

    Full Text Available Naval aircrafts are in parking condition in 90% of their life time. The most important factors that influence the environmental adaptability of naval aircrafts include marine atmospheric environment and the induced environment formed by heat and waste air from equipments. The main environmental damage of foreign naval aircrafts during service is the corrosion of structures and components, which is the most severe safety issue for aeronautical equipment. Naval aircrafts in China exhibits environmental damage related to structures, components and electronic devices. Environmental adaptability research on foreign naval aircrafts is focused on accumulation of shipborne environmental data, new testing methods for the shipborne environment, the combination of environmental testing methods and naval aircraft life time task characters, and the application of naval aircraft environmental data. Environmental adaptability research of naval aircrafts in China is mainly in three aspects: measurement and analysis of shipborne environment, the impact of shipborne environment, and environmental testing methods for simulation of shipborne environment. The future research is outlooked. It is considered that the changing rules of environmental effects of typical materials, corrosion susceptible structures, and aircraft electric products in shipborne environment should be studied. Environment factor data should be accumulated with the corresponding environment spectrum established. Laboratory testing methods and equipment simulating accelerated shipborne environment should be established for corrosion susceptible structures in order to support the environmental engineering work for naval aircraft.

  12. Damage assessment of nuclear containment against aircraft crash

    Energy Technology Data Exchange (ETDEWEB)

    Iqbal, Mohd Ashraf, E-mail: iqbal_ashraf@rediffmail.com; Sadique, Md. Rehan, E-mail: rehan.sadique@gmail.com; Bhargava, Pradeep, E-mail: bhpdpfce@iitr.ac.in; Bhandari, N.M., E-mail: nmbcefce@iitr.ac.in

    2014-10-15

    Highlights: • Damage assessment of nuclear containment is studied against aircraft crash. • Four impact locations have been identified at the outer containment shell. • The mid of the total height has been found to be most vulnerable location. • The crown of dome has been found to be the strongest location. • Phantom F4 caused more localized and severe damage compared to other aircrafts. - Abstract: The behavior of nuclear containment structure has been studied against aircraft crash with an emphasis on the influence of strike location. The impact locations identified on the BWR Mark III type nuclear containment structure are mid-height, junction of dome and cylinder, crown of dome and arc of dome. The containment at each of the above locations has been impacted normally by Phantom F-4, Boeing 707-320 and Airbus A320 aircrafts. The loading of the aircraft has been assigned through the corresponding reaction-time response curve. ABAQUS/Explicit finite element code has been used to carry out the three-dimensional numerical simulations. The concrete damaged plasticity model was used to simulate the behavior of concrete while the behavior of steel reinforcement was incorporated using the Johnson–Cook elasto-viscoplastic material model. The mid-height of containment has been found to experience most severe deformation against each aircraft. Phantom F4 has been found to be most disastrous at each location. The results have been compared with those of the available studies with respect to the containment deformation.

  13. Aircraft Data Acquisition

    OpenAIRE

    Elena BALMUS

    2016-01-01

    The introduction of digital systems instead of analog ones has created a major separation in the aviation technology. Although the digital equipment made possible that the increasingly faster controllers take over, we should say that the real world remains essentially analogue [4]. Fly-by-wire designers attempting to control and measure the real feedback of an aircraft were forced to find a way to connect the analogue environment to their digital equipment. In order to manage the implications...

  14. Airline and Aircraft Reliability

    OpenAIRE

    Hauka, Maris; Paramonovs, Jurijs

    2014-01-01

    Development of the inspection programme of fatigue-prone aircraft construction under limitation of airline fatigue failure rate. The highest economical effectiveness of airline under limitation of fatigue failure rate and failure probability is discussed. For computing is used exponential regression, Monte Carlo method, Log Normal distribution, Markov chains and semi-Markov process theory. The minimax approach is offered for processing the results of full-scale fatigue approval test of an air...

  15. Slotted Aircraft Wing

    Science.gov (United States)

    McLean, James D. (Inventor); Witkowski, David P. (Inventor); Campbell, Richard L. (Inventor)

    2006-01-01

    A swept aircraft wing includes a leading airfoil element and a trailing airfoil element. At least one full-span slot is defined by the wing during at least one transonic condition of the wing. The full-span slot allows a portion of the air flowing along the lower surface of the leading airfoil element to split and flow over the upper surface of the trailing airfoil element so as to achieve a performance improvement in the transonic condition.

  16. 50 years of transonic aircraft design

    Science.gov (United States)

    Jameson, Antony; Ou, Kui

    2011-07-01

    This article traces the evolution of long range jet transport aircraft over the 50 years since Kuechemann founded the journal Progress in Aerospace Sciences. The article is particularly focused on transonic aerodynamics. During Kuechemann's life time a good qualitative understanding had been achieved of transonic flow and swept wing design, but transonic flow remained intractable to quantitative prediction. During the last 50 years this situation has been completely transformed by the introduction of sophisticated numerical algorithms and an astonishing increase in the available computational power, with the consequence that aerodynamic design is now carried out largely by computer simulation. Moreover developments in aerodynamic shape optimization based on control theory enable a competitive swept wing to be designed in just two simulations, as illustrated in the article. While the external appearance of long range jet aircraft has not changed much, advances in information technology have actually transformed the entire design and manufacturing process through parallel advances in computer aided design (CAD), computational structural mechanics (CSM) and multidisciplinary optimization (MDO). They have also transformed aircraft operations through the adoption of digital fly-by-wire and advanced navigational techniques.

  17. The use of trauma interprofessional simulated education (TIPSE) to enhance role awareness in the emergency department setting.

    Science.gov (United States)

    Brown, Craig William; Howard, Morag; Morse, Jerry

    2016-05-01

    Interprofessional simulation-based education (IPSE) is common in medicine and nursing curricula, however, less evident in diagnostic radiography. Previous work suggests graduate radiographers are unprepared in terms of trauma knowledge and experience. A trauma IPSE programme as a joint venture between two universities was developed. Our aim was to explore the views of radiography, nursing, and medical students regarding preparedness for trauma practice. Second-year radiography (n = 39), nursing (n = 10), and medical (n = 5) students were invited to participate in trauma simulations. Pre- and post-scenario questionnaires were completed and quantitative analysis undertaken. Prior to IPSE, the majority of students were unprepared to manage trauma. Post-scenario felt significantly more prepared to undertake their role in the team and had better understanding of their and other professions' roles in trauma (P < 0.01). IPSE is an effective means of preparing undergraduate students in understanding both their and other professional's roles within the trauma team.

  18. On the unification of aircraft ultrafine particle emission data

    Energy Technology Data Exchange (ETDEWEB)

    Kaercher, B.; Busen, R. [DLR Deutsches Zentrum fuer Luft- und Raumfahrt e.V., Wessling (Germany). Inst. fuer Physik der Atmosphaere; Turco, R.P.; Yu Fangqun [California Univ., Los Angeles, CA (United States). Dept. of Atmospheric Sciences; Danilin, M.Y.; Weisenstein, D.K. [Atmospheric and Environmental Research, Inc., Cambridge, MA (United States); Miake-Lye, R.C. [Aerodyne Research, Inc., Billerica, MA (United States)

    2000-03-01

    To predict the environmental impacts of future commercial aviation, intensive studies have been launched to measure the properties and effects of aircraft emissions. These observations have revealed an extremely wide variance with respect to the number and sizes of the particles produced in the exhaust plumes. Aircraft aerosol ultimately contributes to the population of cloud-forming nuclei, and may lead to significant global radiative and chemical perturbations. In this paper, recent discoveries are coordinated and unified in the form of a physically consistent plume aerosol model that explains most of the observational variance. Using this new approach, it is now practical to carry out reliable global atmospheric simulations of aircraft effects, as demonstrated by a novel assessment of the perturbation of the stratospheric aerosol layer by a supersonic aircraft fleet. (orig.)

  19. Aircraft recognition based on the discrepancy of polygon intersection area

    Science.gov (United States)

    Deng, Xiujian; Wang, Yanfang; Feng, Qi

    2017-01-01

    In this paper, a new algorithm that based on discrepancy of polygon intersection area for aircraft recognition is presented. The recognition algorithm process involves three parts: generating polygon of aircraft, placing overlapping plane polygons and computing the area of total intersecting polygons. For the purpose of getting the polygon of aircraft, the picture that was ready to be recognized has gone through a series of pre-processing and the smallest circumference polygon algorithm was used to get approximate polygon of the target contour. To make the two compared polygons have the approximate area, the similar principle was utilized. The matching procedure was divided into four steps including computing intersecting points, computing polygon intersecting sets, computing the intersecting area and getting the intersecting rate to recognize the aircraft. The data structure of algorithm is based on doubly liked list principle. A mass of simulations illustrate that the proposed algorithm is effective and reasonable.

  20. The research of optical windows used in aircraft sensor systems

    Institute of Scientific and Technical Information of China (English)

    Zhou Feng; Li Yan; Tang Tian-Jin

    2012-01-01

    The optical windows used in aircrafts protect their imaging sensors from environmental effects.Considering the imaging performance,flat surfaces are traditionally used in the design of optical windows.For aircrafts operating at high speeds,the optical windows should be relatively aerodynamic,but a flat optical window may introduce unacceptably high drag to the airframes.The linear scanning infrared sensors used in aircrafts with,respectively,a fiat window,a spherical window and a toric window in front of the aircraft sensors are designed and compared.Simulation results show that the optical design using a toric surface has the integrated advantages of field of regard,aerodynamic drag,narcissus effect,and imaging performance,so the optical window with a toric surface is demonstrated to be suited for this application.

  1. On the unification of aircraft ultrafine particle emission data

    Energy Technology Data Exchange (ETDEWEB)

    Kaercher, B.; Busen, R. [DLR Deutsches Zentrum fuer Luft- und Raumfahrt e.V., Wessling (Germany). Inst. fuer Physik der Atmosphaere; Turco, R.P.; Yu Fangqun [California Univ., Los Angeles, CA (United States). Dept. of Atmospheric Sciences; Danilin, M.Y.; Weisenstein, D.K. [Atmospheric and Environmental Research, Inc., Cambridge, MA (United States); Miake-Lye, R.C. [Aerodyne Research, Inc., Billerica, MA (United States)

    2000-03-01

    To predict the environmental impacts of future commercial aviation, intensive studies have been launched to measure the properties and effects of aircraft emissions. These observations have revealed an extremely wide variance with respect to the number and sizes of the particles produced in the exhaust plumes. Aircraft aerosol ultimately contributes to the population of cloud-forming nuclei, and may lead to significant global radiative and chemical perturbations. In this paper, recent discoveries are coordinated and unified in the form of a physically consistent plume aerosol model that explains most of the observational variance. Using this new approach, it is now practical to carry out reliable global atmospheric simulations of aircraft effects, as demonstrated by a novel assessment of the perturbation of the stratospheric aerosol layer by a supersonic aircraft fleet. (orig.)

  2. THE ROLE OF A FLUX ROPE EJECTION IN A THREE-DIMENSIONAL MAGNETOHYDRODYNAMIC SIMULATION OF A SOLAR FLARE

    Energy Technology Data Exchange (ETDEWEB)

    Nishida, Keisuke; Shibata, Kazunari [Kwasan and Hida Observatories, Kyoto University, Yamashina, Kyoto 607-8471 (Japan); Nishizuka, Naoto, E-mail: nishida@kwasan.kyoto-u.ac.jp [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan)

    2013-10-01

    We investigated the dynamic evolution of a three-dimensional (3D) flux rope eruption and magnetic reconnection process in a solar flare by simply extending the two-dimensional (2D) resistive magnetohydrodynamic simulation model of solar flares with low β plasma to a 3D model. We succeeded in reproducing a current sheet and bi-directional reconnection outflows just below the flux rope during the eruption in our 3D simulations. We calculated four cases of a strongly twisted flux rope and a weakly twisted flux rope in 2D and 3D simulations. The time evolution of a weakly twisted flux rope in the 3D simulation shows behaviors similar to those of the 2D simulation, while a strongly twisted flux rope in the 3D simulation clearly shows a different time evolution from the 2D simulation except for the initial phase evolution. The ejection speeds of both strongly and weakly twisted flux ropes in 3D simulations are larger than in the 2D simulations, and the reconnection rates in 3D cases are also larger than in the 2D cases. This indicates positive feedback between the ejection speed of a flux rope and the reconnection rate even in the 3D simulation, and we conclude that the plasmoid-induced reconnection model can be applied to 3D. We also found that small-scale plasmoids are formed inside a current sheet and make it turbulent. These small-scale plasmoid ejections have a role in locally increasing the reconnection rate intermittently as observed in solar flares, coupled with a global eruption of a flux rope.

  3. Ditching Numerical Simulations: Recent Steps in Industrial Applications

    OpenAIRE

    Benítez Montañés, Luis; Climent Máñez, Héctor; Siemann, Martin; Kohlgrueber, Dieter

    2012-01-01

    Ditching is an aircraft emergency condition that ends with planned impact of the aircraft on water. The high forward velocity in fixed-wing aircraft ditching affects the aircraft dynamics and its structural response due to complex hydrodynamic effects. Therefore, analysis of ditching impact is particularly relevant to satisfy the airworthiness regulations for modern aircraft. Numerical methods for simulating ditching take advantage of the computational capacity allowing industry to deal w...

  4. Nonlinear feedback control of highly manoeuvrable aircraft

    Science.gov (United States)

    Garrard, William L.; Enns, Dale F.; Snell, S. A.

    1992-01-01

    This paper describes the application of nonlinear quadratic regulator (NLQR) theory to the design of control laws for a typical high-performance aircraft. The NLQR controller design is performed using truncated solutions of the Hamilton-Jacobi-Bellman equation of optimal control theory. The performance of the NLQR controller is compared with the performance of a conventional P + I gain scheduled controller designed by applying standard frequency response techniques to the equations of motion of the aircraft linearized at various angles of attack. Both techniques result in control laws which are very similar in structure to one another and which yield similar performance. The results of applying both control laws to a high-g vertical turn are illustrated by nonlinear simulation.

  5. Aircraft propeller induced structure-borne noise

    Science.gov (United States)

    Unruh, James F.

    1989-01-01

    A laboratory-based test apparatus employing components typical of aircraft construction was developed that would allow the study of structure-borne noise transmission due to propeller induced wake/vortex excitation of in-wake structural appendages. The test apparatus was employed to evaluate several aircraft installation effects (power plant placement, engine/nacelle mass loading, and wing/fuselage attachment methods) and several structural response modifications for structure-borne noise control (the use of wing blocking mass/fuel, wing damping treaments, and tuned mechanical dampers). Most important was the development of in-flight structure-borne noise transmission detection techniques using a combination of ground-based frequency response function testing and in-flight structural response measurement. Propeller wake/vortex excitation simulation techniques for improved ground-based testing were also developed to support the in-flight structure-borne noise transmission detection development.

  6. Numerical Simulation on High-Speed Fragment Impact Against an Aircraft Fuel Tank%高速破片撞击飞机油箱的数值模拟研究

    Institute of Scientific and Technical Information of China (English)

    白强本; 李向东; 贾飞; 杨亚东

    2014-01-01

    In order to evaluate the damage of fuel tanks for aircrafts by hydrodynamic ram (HRAM) event, the damage of characteristics of a water-filled tank facing a fragment impacting are calculated by numerical simulation method of given velocity fragment and the Arbitrary Lagrangian-Eulerian (ALE) technique, the results of tank wall damage are compared with different velocities of fragments and different water filling ratios. The research results show: the damage impacting a full-filed tank is more serious than impacting an empty one, the entry and exit walls relative to the impacted shell have the most serious damage. With the fragment velocity increasing, the deformations on the entry and exit wall are also increasing. The deformation of part-filled tank wall is much smaller than full-filled tank wall. The deformation on 75%filled tank and 85%filled tank is relatively close.%为研究飞机油箱在水锤作用下的破坏效应,运用数值计算方法对高速破片撞击充水箱体的破坏响应进行研究。采用赋予破片速度和ALE建模的方法数值模拟高速破片撞击充水箱体的破坏响应,并对不同破片速度和不同充水比下箱体的变形进行比较分析。计算结果表明:破片撞击充水箱体时的破坏效应较空箱体要严重得多,箱体前后壁的穿孔处周围是发生破坏最严重的区域;箱体前后壁的变形量随破片速度的增加而增加;部分充水箱体的变形明显小于完全充水的情况,但对于充水75%和85%的箱体变形差距不大。

  7. Evaluating the impact of role-playing simulations on global competency in an online transnational engineering course

    Science.gov (United States)

    Wold, Kari

    Successfully interacting with those from different cultures is essential to excel in any field, particularly when global, transnational collaborations in the workplace are increasingly common. However, many higher education students in engineering are not explicitly taught how to display the global competency skills desired by future employers. To display global competency skills means students must be able to visibly respect and recognize differences among those from different cultures. Global competency also means students must be able to show they can adjust their behaviors and integrate others' ideas when working with those with cultural backgrounds other than their own. While these skills are now deemed essential for future engineers, many institutions are struggling with determining which strategies and activities are universally effective to allow students to practice the global competency skills now crucial for success. Immersing engineering students in interactive role-playing simulations in transnational environments is one way institutions are encouraging students to illustrate and develop global competency skills. Role-playing simulations in transnational education provide environments where students adopt roles, interact with other students, and together explore and address realistic global problems. However, no studies have addressed whether or how role-playing simulations can help develop global competency in transnational engineering courses, students' perceptions regarding whether they change their abilities to display global competency in those environments, and their perspectives the effectiveness of using role-playing simulations for this purpose. To address this gap, this study assesses the impact of two subsequent role-playing simulations involving nuclear energy policy in a transnational course involving engineering students from the University of Virginia in Charlottesville, Virginia, and from Technische Universitat Dortmund in Dortmund

  8. Aircraft automatic flight control system with model inversion

    Science.gov (United States)

    Smith, G. A.; Meyer, George

    1990-01-01

    A simulator study was conducted to verify the advantages of a Newton-Raphson model-inversion technique as a design basis for an automatic trajectory control system in an aircraft with highly nonlinear characteristics. The simulation employed a detailed mathematical model of the aerodynamic and propulsion system performance characteristics of a vertical-attitude takeoff and landing tactical aircraft. The results obtained confirm satisfactory control system performance over a large portion of the flight envelope. System response to wind gusts was satisfactory for various plausible combinations of wind magnitude and direction.

  9. Aircraft automatic flight control system with model inversion

    Science.gov (United States)

    Smith, G. A.; Meyer, George

    1990-01-01

    A simulator study was conducted to verify the advantages of a Newton-Raphson model-inversion technique as a design basis for an automatic trajectory control system in an aircraft with highly nonlinear characteristics. The simulation employed a detailed mathematical model of the aerodynamic and propulsion system performance characteristics of a vertical-attitude takeoff and landing tactical aircraft. The results obtained confirm satisfactory control system performance over a large portion of the flight envelope. System response to wind gusts was satisfactory for various plausible combinations of wind magnitude and direction.

  10. Investigating the role of water in the Diffusion of Cholera using Agent-Based simulation

    Science.gov (United States)

    Augustijn, Ellen-Wien; Doldersum, Tom; Augustijn, Denie

    2014-05-01

    Traditionally, cholera was considered to be a waterborne disease. Currently we know that many other factors can contribute to the spread of this disease including human mobility and human behavior. However, the hydrological component in cholera diffusion is significant. The interplay between cholera and water includes bacteria (V. cholera) that survive in the aquatic environment, the possibility that run-off water from dumpsites carries the bacteria to surface water (rivers and lakes), and when the bacteria reach streams they can be carried downstream to infect new locations. Modelling is a very important tool to build theory on the interplay between different types of transmission mechanisms that together are responsible for the spread of Cholera. Agent-based simulation models are very suitable to incorporate behavior at individual level and to reproduce emergence. However, it is more difficult to incorporate the hydrological components in this type of model. In this research we present the hydrological component of an Agent-Based Cholera model developed to study a Cholera epidemic in Kumasi (Ghana) in 2005. The model was calibrated on the relative contribution of each community to the distributed pattern of cholera rather than the absolute number of incidences. Analysis of the results shows that water plays an important role in the diffusion of cholera: 75% of the cholera cases were infected via river water that was contaminated by runoff from the dumpsites. To initiate infections upstream, the probability of environment-to-human transmission seemed to be overestimated compared to what may be expected from literature. Scenario analyses show that there is a strong relation between the epidemic curve and the rainfall. Removing dumpsites that are situated close to the river resulted in a strong decrease in the number of cholera cases. Results are sensitive to the scheduling of the daily activities and the survival time of the cholera bacteria.

  11. 19 CFR 122.64 - Other aircraft.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Other aircraft. 122.64 Section 122.64 Customs... AIR COMMERCE REGULATIONS Clearance of Aircraft and Permission To Depart § 122.64 Other aircraft. Clearance or permission to depart shall be requested by the aircraft commander or agent for aircraft covered...

  12. Input Excitation Techniques for Aerodynamic Derivatives Estimation of Highly Augmented Fighter Aircraft

    Directory of Open Access Journals (Sweden)

    N. Shantha Kumar

    1999-07-01

    Full Text Available This paper presents the results of an investigation related to the estimation of lateral-directional aerodynamic derivatives of highly augmented and advanced fighter aircraft from the flight like response data. Different types of pilot inputs are used to generate aircraft response data in the engineer-in-loop flight simulator to determine which input excitation flight provide the most accurate estimates of aircraft stability and control derivatives. Also, MATILABI SIMULINK-based simulation platform is used to generate aircraft response with single-surface excitation to evaluate the usefulness of the method for stability and control derivatives estimation. The maximum likelihood estimation, based on output error utilisation technique is used to estimate the derivatives from the aircraft simulation response data. The results indicate that accuracy of the estimated derivatives improve with persistence excitation and single-surface excitation.

  13. Point-of-care ultrasound education: the increasing role of simulation and multimedia resources.

    Science.gov (United States)

    Lewiss, Resa E; Hoffmann, Beatrice; Beaulieu, Yanick; Phelan, Mary Beth

    2014-01-01

    This article reviews the current technology, literature, teaching models, and methods associated with simulation-based point-of-care ultrasound training. Patient simulation appears particularly well suited for learning point-of-care ultrasound, which is a required core competency for emergency medicine and other specialties. Work hour limitations have reduced the opportunities for clinical practice, and simulation enables practicing a skill multiple times before it may be used on patients. Ultrasound simulators can be categorized into 2 groups: low and high fidelity. Low-fidelity simulators are usually static simulators, meaning that they have nonchanging anatomic examples for sonographic practice. Advantages are that the model may be reused over time, and some simulators can be homemade. High-fidelity simulators are usually high-tech and frequently consist of many computer-generated cases of virtual sonographic anatomy that can be scanned with a mock probe. This type of equipment is produced commercially and is more expensive. High-fidelity simulators provide students with an active and safe learning environment and make a reproducible standardized assessment of many different ultrasound cases possible. The advantages and disadvantages of using low- versus high-fidelity simulators are reviewed. An additional concept used in simulation-based ultrasound training is blended learning. Blended learning may include face-to-face or online learning often in combination with a learning management system. Increasingly, with simulation and Web-based learning technologies, tools are now available to medical educators for the standardization of both ultrasound skills training and competency assessment.

  14. The emerging role of screen based simulators in the training and assessment of colonoscopists

    OpenAIRE

    Cunningham, Morven; Fernando, Bimbi; Berlingieri, Pasquale

    2010-01-01

    Incorporation of screen based simulators into medical training has recently gained momentum, as advances in technology have coincided with a government led drive to increase the use of medical simulation training to improve patient safety with progressive reductions in working hours available for junior doctors to train. High fidelity screen based simulators hold great appeal for endoscopy training. Potentially, their incorporation into endoscopy training curricula could enhance speed of acqu...

  15. Role of simulation model in petroleum exploration. Have we developed new ideas for exploration; Sekiyu tanko ni okeru simulation no yakuwari. Hatashite wareware no shikoho wa kawattanoka

    Energy Technology Data Exchange (ETDEWEB)

    Nakayama, K. [Japex Jeoscience Institute, Tokyo (Japan)

    1998-01-01

    This paper describes a role of simulation model in petroleum exploration based on geology. Geology is based on inductive method in which a scientific fact can be extracted and estimated from the pile of descriptive records. Such an inductive method is called a backward model. While, geophysics is based on a deductive method in which a physical or mathematical model is developed assuming a uniformitarialism in the past before extracting a scientific fact through the model calibration. Such a deductive method is called forward model. Introduction of simulation model has been useful for petroleum exploration due to its deductive property. However, some conceptualization and simplification are introduced in such a method. Therefore, its accuracy is still far from the fact. However, objective concept can be obtained to certain degree. Simulation modeling is one of a significant methods by which petroleum exploration can be activated and new ideas can be created in the field of petroleum geology. It is required to apply the simulation modeling by checking it using conventional inductive method. 12 refs., 7 figs.

  16. Role of Boundary Conditions in Monte Carlo Simulation of MEMS Devices

    Science.gov (United States)

    Nance, Robert P.; Hash, David B.; Hassan, H. A.

    1997-01-01

    A study is made of the issues surrounding prediction of microchannel flows using the direct simulation Monte Carlo method. This investigation includes the introduction and use of new inflow and outflow boundary conditions suitable for subsonic flows. A series of test simulations for a moderate-size microchannel indicates that a high degree of grid under-resolution in the streamwise direction may be tolerated without loss of accuracy. In addition, the results demonstrate the importance of physically correct boundary conditions, as well as possibilities for reducing the time associated with the transient phase of a simulation. These results imply that simulations of longer ducts may be more feasible than previously envisioned.

  17. Simulating the physician as healthcare manager: An innovative course to train for the manager role

    Directory of Open Access Journals (Sweden)

    Gradel, Maximilian

    2016-05-01

    Full Text Available Introduction: During their formal studies medical students acquire extensive medical expertise. However, the medical profession demands additional competencies, such as those involved in efficient resource allocation, business administration, development, organization, and process management in the healthcare system. At present students are not sufficiently prepared for the physician’s role as manager. In response, we designed the seminar course, MeCuM-SiGma, to impart basic knowledge about healthcare policy and management to students of medicine. This project report describes our teaching strategies and the initial evaluation of this educational project.Project description: In this semester-long, seminar course introduced in 2010, medical students gather experience with the competencies mentioned above as well as learn basic management skills. The course is offered each winter semester, and students sign up to attend voluntarily; course coordination and organization is done on a voluntary basis by physicians and employees of the Mentoring Office (MeCuM-Mentor at the Medical School of the Ludwig Maximilian University (LMU in Munich, Germany. The course is open to all students enrolled at the two medical schools in Munich.During the first part of this elective, students learn about the basic principles of the German political and healthcare systems in case-based, problem-based tutorials led by trained tutors and in lectures held by experts.In the second part of the course students take on the roles of the University Hospital’s executive board of directors and supervisory board to work on an existing hospital project as a group within the scope of a simulation. This phase of the course is accompanied by workshops conducted in cooperation with university-based and off-campus partners that address the procedural learning objectives (teamwork, project management, negotiation strategies, etc..A suitable, authentic issue currently facing the

  18. Scheduling of an aircraft fleet

    Science.gov (United States)

    Paltrinieri, Massimo; Momigliano, Alberto; Torquati, Franco

    1992-01-01

    Scheduling is the task of assigning resources to operations. When the resources are mobile vehicles, they describe routes through the served stations. To emphasize such aspect, this problem is usually referred to as the routing problem. In particular, if vehicles are aircraft and stations are airports, the problem is known as aircraft routing. This paper describes the solution to such a problem developed in OMAR (Operative Management of Aircraft Routing), a system implemented by Bull HN for Alitalia. In our approach, aircraft routing is viewed as a Constraint Satisfaction Problem. The solving strategy combines network consistency and tree search techniques.

  19. Modeling the Fate of Expiratory Aerosols and the Associated Infection Risk in an Aircraft Cabin Environment

    DEFF Research Database (Denmark)

    Wan, M.P.; To, G.N.S.; Chao, C.Y.H.

    2009-01-01

    The transport and deposition of polydispersed expiratory aerosols in an aircraft cabin were simulated using a Lagrangian-based model validated by experiments conducted in an aircraft cabin mockup. Infection risk by inhalation was estimated using the aerosol dispersion data and a model was developed...

  20. Role of subgrid-scale modeling in large eddy simulation of wind turbine wake interactions

    DEFF Research Database (Denmark)

    Sarlak, Hamid; Meneveau, C.; Sørensen, Jens Nørkær

    2015-01-01

    A series of simulations are carried out to evaluate specific features of the Large Eddy Simulation (LES) technique in wind turbine wake interactions. We aim to model wake interactions of two aligned model rotors. The effects of the rotor resolution, actuator line force filter size, and Reynolds...

  1. The role of plasticity in the integrated approach of subsequent simulations of car structures

    NARCIS (Netherlands)

    Rietman, B.; Kose, K.

    2002-01-01

    In the development of car structures the performance (i.e. dynamic behavior, fatigue life) is analyzed by prototype testing and simulation. Nowadays, the simulations are based on the geometry that is obtained directly from the CAD construction. It is known however, that forming can change the materi

  2. CapDEM TD - Modeling and Simulation (Role and Tools) State of the Art Report

    Science.gov (United States)

    2005-01-01

    organisationnelle, ses processus et ses fonctions ainsi que les echanges d’information entre ses entites; Modeliser et simuler les processus...describe, simulate. evaluate, and refine a system’s behavior through standard and custom block libraries. Simulink integrates seamlessly with MATLAB

  3. Commercial Aircraft Protection

    Energy Technology Data Exchange (ETDEWEB)

    Ehst, David A. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-10-26

    This report summarizes the results of theoretical research performed during 3 years of P371 Project implementation. In results of such research a new scientific conceptual technology of quasi-passive individual infrared protection of heat-generating objects – Spatial Displacement of Thermal Image (SDTI technology) was developed. Theoretical substantiation and description of working processes of civil aircraft individual IR-protection system were conducted. The mathematical models and methodology were presented, there were obtained the analytical dependencies which allow performing theoretical research of the affect of intentionally arranged dynamic field of the artificial thermal interferences with variable contrast onto main parameters of optic-electronic tracking and homing systems.

  4. Hydrogen aircraft technology

    Science.gov (United States)

    Brewer, G. D.

    1991-01-01

    A comprehensive evaluation is conducted of the technology development status, economics, commercial feasibility, and infrastructural requirements of LH2-fueled aircraft, with additional consideration of hydrogen production, liquefaction, and cryostorage methods. Attention is given to the effects of LH2 fuel cryotank accommodation on the configurations of prospective commercial transports and military airlifters, SSTs, and HSTs, as well as to the use of the plentiful heatsink capacity of LH2 for innovative propulsion cycles' performance maximization. State-of-the-art materials and structural design principles for integral cryotank implementation are noted, as are airport requirements and safety and environmental considerations.

  5. Optics in aircraft engines

    Science.gov (United States)

    Vachon, James; Malhotra, Subhash

    The authors describe optical IR&D (independent research and development) programs designed to demonstrate and evaluate optical technologies for incorporation into next-generation military and commercial aircraft engines. Using a comprehensive demonstration program to validate this technology in an on-engine environment, problems encountered can be resolved early and risk can be minimized. In addition to specific activities related to the optics demonstration on the fighter engine, there are other optical programs underway, including a solenoid control system, a light off detection system, and an optical communication link. Research is also underway in simplifying opto-electronics and exploiting multiplexing to further reduce cost and weight.

  6. Aircraft propeller control

    Science.gov (United States)

    Day, Stanley G. (Inventor)

    1990-01-01

    In the invention, the speeds of both propellers in a counterrotating aircraft propeller pair are measured. Each speed is compared, using a feedback loop, with a demanded speed and, if actual speed does not equal demanded speed for either propeller, pitch of the proper propeller is changed in order to attain the demanded speed. A proportional/integral controller is used in the feedback loop. Further, phase of the propellers is measured and, if the phase does not equal a demanded phase, the speed of one propeller is changed, by changing pitch, until the proper phase is attained.

  7. [Application of role-play simulation in pre-clinical practice of the fourth grade students in department of endodontics].

    Science.gov (United States)

    Zhu, Lin-lin; Qiu, Li-hong; Qu, Liu; Xue, Ming; Yan, Lu

    2014-10-01

    To apply role- play simulation in pre-clinical practice of the fourth grade students in department of endodontics. Thirty-two students were randomly divided into 2 groups, there were 16 students in each group. Students in one group were taught with role-play simulation while the other group with lecture-based learning method. The teaching effect was measured with examination and questionnaire survey. The data was analyzed by using SPSS 17.0 software package. There were no significant differences in basic knowledge, case analysis and oral examination between 2 groups (P>0.05), but there was significant difference in history taking and medical records writing, practical examination and total scores between 2 groups (Pendodontics.

  8. Fostering integrated learning and clinical professionalism using contextualized simulation in a small-group role-play.

    Science.gov (United States)

    Baillie, Sarah; Pierce, Stephanie E; May, Stephen A

    2010-01-01

    Teaching and learning in a clinical setting is important in veterinary and medical training but presents many challenges, including providing enough hands-on experience while not putting patients (animal or human) at risk. Some of the issues have been addressed with the introduction of clinical skills laboratories and communication skills training using role play. However, in both instances skills are learned in isolation, whereas the real task requires the integration of many skills including technical competencies, effective communication, decision making, and professionalism. In our study, we trialed "contextualized simulation" by combining role play with a simulator, the haptic cow, in a small-group tutorial, the Simulated Fertility Visit. Students took turns as the veterinarian; they had to establish the cow's history from the farmer (a role player), palpate the simulation, make a diagnosis, and decide on treatment, if appropriate. We included scenarios varying from common cases to challenging situations. The tutorial was introduced in the farm-animal clinical rotation, and feedback was gathered from students by means of a questionnaire. The tutorial was attended by 178 students (98% of that year's students), and 151 questionnaires were returned (85% response rate). Students reported that the tutorial was a positive learning experience and recognized that it presented an opportunity to integrate the skills needed for clinical work. Student feedback suggests that contextualized simulation provides a valuable complement to clinical cases, and we recommend extending this teaching method to other clinical scenarios and species, particularly because it provides a safe environment in which to experience, and learn from, mistakes.

  9. Role of water states on water uptake and proton transport in Nafion using molecular simulations and bimodal network

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Gi Suk [Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Mechanical Engineering; Kaviany, Massoud [Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Mechanical Engineering; Gostick, Jeffrey T. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Environmental Energy Technologies Division; Kientiz, Brian [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Environmental Energy Technologies Division; Weber, Adam Z. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Environmental Energy Technologies Division; Kim, Moo Hwan [Pohang Univ. of Science and Technology (POSTECH) (Korea, Republic of). Dept. of Mechanical Engineering

    2011-04-07

    In this paper, using molecular simulations and a bimodal-domain network, the role of water state on Nafion water uptake and water and proton transport is investigated. Although the smaller domains provide moderate transport pathways, their effectiveness remains low due to strong, resistive water molecules/domain surface interactions. Finally, the water occupancy of the larger domains yields bulk-like water, and causes the observed transition in the water uptake and significant increases in transport properties.

  10. Coordination control of quadrotor VTOL aircraft in three-dimensional space

    Science.gov (United States)

    Do, K. D.

    2015-03-01

    This paper presents a constructive design of distributed coordination controllers for a group of N quadrotor vertical take-off and landing (VTOL) aircraft in three-dimensional space. A combination of Euler angles and unit-quaternion for the attitude representation of the aircraft is used to result in an effective control design, and to reduce singularities in the aircraft's dynamics. The coordination control design is based on a new bounded control design technique for second-order systems and new pairwise collision avoidance functions. The pairwise collision functions are functions of both relative positions and relative velocities between the aircraft instead of only their relative positions as in the literature. To overcome the inherent underactuation of the aircraft, the roll and pitch angles of the aircraft are considered as immediate controls. Simulations illustrate the results.

  11. A NASA study of the impact of technology on future sea based attack aircraft

    Science.gov (United States)

    Hahn, Andrew S.

    1992-01-01

    A conceptual aircraft design study was recently completed evaluating carrier-based, subsonic attack aircraft using contemporary and future technology assumptions. The study examined a configuration matrix that was made up of light and medium bomb loads, one and two man crews, internal and external weapons carriage, as well as conventional and flying wing planforms. Use of common technology assumptions, engine cycle simulation code, design mission, and consistent application of methods allow for direct comparison of the aircraft. This paper describes the design study ground rules and the aircraft designed. The aircraft descriptions include weights, dimensions, layout, design mission, design constraints, maneuver performance, and fallout mission performance. The strengths, and weaknesses of each aircraft are highlighted.

  12. Advanced energy systems (APU) for large commercial aircraft

    Energy Technology Data Exchange (ETDEWEB)

    Westenberger, A.; Bleil, J.; Arendt, M. [Airbus Deutschland GmbH, Hamburg (Germany)

    2013-06-01

    The intention of using a highly integrated component using on fuel cell technology installed on board of large commercial passenger aircraft for the generation of onboard power for the systems demand during an entire aircraft mission was subject of several studies. The results of these studies have been based on the simulation of the whole system in the context of an aircraft system environment. In front of the work stood the analyses of different fuel cell technologies and the analyses of the aircraft system environment. Today onboard power is provided on ground by an APU and in flight by the main engines. In order to compare fuel cell technology with the today's usual gas turbine operational characteristics have been analysed. A second analysis was devoted to the system demand for typical aircraft categories. The MEA system concept was supposed in all cases. The favourable concept represented an aircraft propelled by conventional engines with starter generator units, providing AC electrical power, covering in total proximately half of the power demand and a component based on fuel cell technology. This component provided electrical DC power, clean potable water, thermal energy at 180 degrees Celsius and nitrogen enriched air for fire suppression and fire extinguishing agent. In opposite of a usual gas turbine based APU, this new unit was operated as the primary power system. (orig.)

  13. 基于传感器的飞机地面除冰模拟实验研究%Study on simulation experiment for aircraft ground deicing based on sensor

    Institute of Scientific and Technical Information of China (English)

    王立文; 赵亮; 陈斌

    2013-01-01

    飞机除冰是影响民航冬季安全运行的重要因素之一,为了优化飞机除冰液参数,设计了飞机地面除冰室外实验.在冬季室外条件下通过对结冰的模拟机体表面喷射加热的除冰液进行除冰,在除冰过程中对除冰液流量、除冰液温度进行控制,通过安装在机体上的温度传感器和光纤传感器得到飞机机体表面温度变化和冰层厚度变化情况.通过分析实验结果可得:在一定范围内,除冰液温度升高能有效提高除冰速率;除冰液流量增加也能提高除冰速率,但当除冰液流量超过一定值时,射流冲击成为除冰的主要动力.%Aircraft icing is one of the important factors that affect civil aviation safety in operation in winter.In order to optimize parameters of aircraft deicing fluid,aircraft ground deicing outdoor experiment is carried out.In winter outdoor conditions,aircraft deicing is operated by injecting heated deicing fluid to the aircraft surface.The temperature and the velocity of the flow must be changed regularly,and change of temperature and ice thickness can be detected by temperature sensor and fibre-optic sensor that are installed on the aircraft surface.By analyzing result of experiment,the conclusion is that,in certain range the temperature rise of deicing liquid increases apparently ice removal rate,but the jet impact force will be the main force of deicing when the velocity of flow exceeds certain value.

  14. Aircraft landing using GPS

    Science.gov (United States)

    Lawrence, David Gary

    The advent of the Global Positioning System (GPS) is revolutionizing the field of navigation. Commercial aviation has been particularly influenced by this worldwide navigation system. From ground vehicle guidance to aircraft landing applications, GPS has the potential to impact many areas of aviation. GPS is already being used for non-precision approach guidance; current research focuses on its application to more critical regimes of flight. To this end, the following contributions were made: (1) Development of algorithms and a flexible software architecture capable of providing real-time position solutions accurate to the centimeter level with high integrity. This architecture was used to demonstrate 110 automatic landings of a Boeing 737. (2) Assessment of the navigation performance provided by two GPS-based landing systems developed at Stanford, the Integrity Beacon Landing System, and the Wide Area Augmentation System. (3) Preliminary evaluation of proposed enhancements to traditional techniques for GPS positioning, specifically, dual antenna positioning and pseudolite augmentation. (4) Introduction of a new concept for positioning using airport pseudolites. The results of this research are promising, showing that GPS-based systems can potentially meet even the stringent requirements of a Category III (zero visibility) landing system. Although technical and logistical hurdles still exist, it is likely that GPS will soon provide aircraft guidance in all phases of flight, including automatic landing, roll-out, and taxi.

  15. Auralization of novel aircraft configurations

    NARCIS (Netherlands)

    Arntzen, M.; Bertsch, E.L.; Simons, D.G.

    2015-01-01

    A joint initiative of NLR, DLR, and TU Delft has been initiated to streamline the process of generating audible impressions of novel aircraft configurations. The integrated approach adds to the value of the individual tools and allows predicting the sound of future aircraft before they actually fly.

  16. Predicted electrothermal deicing of aircraft blades

    Science.gov (United States)

    Keith, T. G., Jr.; Masiulaniec, K. C.; Dewitt, K. J.; Chao, D. F.

    1984-01-01

    A finite difference method is presented for the transient two-dimensional simulation of an electrothermal de-icer pad of an aircraft wing or blade. The irregular geometry of the composite ice laden blade is handled by use of a body fitted coordinate transformation. By this approach the various blade layers are mapped into a set of stacked rectangular strips in which the numerical solution takes place. Several heat conduction examples are presented in order to demonstrate the accuracy of the numerical procedure. Ice melting time predictions are made and compared to earlier predictions where possible. Finally, a new graphical presentation of thermal results is shown.

  17. Analysis of Aircraft Control Performance using a Fuzzy Rule Base Representation of the Cooper-Harper Aircraft Handling Quality Rating

    Science.gov (United States)

    Tseng, Chris; Gupta, Pramod; Schumann, Johann

    2006-01-01

    The Cooper-Harper rating of Aircraft Handling Qualities has been adopted as a standard for measuring the performance of aircraft since it was introduced in 1966. Aircraft performance, ability to control the aircraft, and the degree of pilot compensation needed are three major key factors used in deciding the aircraft handling qualities in the Cooper- Harper rating. We formulate the Cooper-Harper rating scheme as a fuzzy rule-based system and use it to analyze the effectiveness of the aircraft controller. The automatic estimate of the system-level handling quality provides valuable up-to-date information for diagnostics and vehicle health management. Analyzing the performance of a controller requires a set of concise design requirements and performance criteria. Ir, the case of control systems fm a piloted aircraft, generally applicable quantitative design criteria are difficult to obtain. The reason for this is that the ultimate evaluation of a human-operated control system is necessarily subjective and, with aircraft, the pilot evaluates the aircraft in different ways depending on the type of the aircraft and the phase of flight. In most aerospace applications (e.g., for flight control systems), performance assessment is carried out in terms of handling qualities. Handling qualities may be defined as those dynamic and static properties of a vehicle that permit the pilot to fully exploit its performance in a variety of missions and roles. Traditionally, handling quality is measured using the Cooper-Harper rating and done subjectively by the human pilot. In this work, we have formulated the rules of the Cooper-Harper rating scheme as fuzzy rules with performance, control, and compensation as the antecedents, and pilot rating as the consequent. Appropriate direct measurements on the controller are related to the fuzzy Cooper-Harper rating system: a stability measurement like the rate of change of the cost function can be used as an indicator if the aircraft is under

  18. Investigation of a Folding Wing Aircraft Using Dynamic Analysis Simulation and Experimental Method%一种折叠翼飞行器动态仿真分析与实验设计

    Institute of Scientific and Technical Information of China (English)

    张伟; 郭晓光; 曹东兴

    2011-01-01

    探讨折叠翼飞行器在飞行过程中的特性,设计一种全尺寸折叠翼飞行器.利用Abaqus软件对该飞行器不同折叠角度状态的模态和动态响应进行分析,结果表明,折叠翼的折叠角度小于90°时,其第3、第4阶模态表现为弯扭组合变形,容易在亚声速条件下发生颤振现象.利用实验方法,设计、制作了试验机并进行试飞,结果发现该试验机后掠角较大,机翼展开后飞行器焦点也相应前移,因此该飞行器在机翼折叠状态下飞行更稳定.%The flight characteristics of a folding wing aircraft are investigated and on this basis, a full-size folding wing aircraft is designed. The aircraft's modes and dynamic characteristics are analyzed by use of CAE softwae Abaqus. It is shown that when the folding angle is smaller than 90 degree, the wing's third and fourth order modes are of bend-torsion-coupled. Thus in the subsonic conditions, the wing would likely be in the flutter state. A folding wing aircrafl model is designed. A number of flight characters are obtained by using the model, and it is shown that the focus point of the aircraft moves forward because of its high sweepback angle, thus

  19. TRACON Aircraft Arrival Planning and Optimization Through Spatial Constraint Satisfaction

    Science.gov (United States)

    Bergh, Christopher P.; Krzeczowski, Kenneth J.; Davis, Thomas J.; Denery, Dallas G. (Technical Monitor)

    1995-01-01

    A new aircraft arrival planning and optimization algorithm has been incorporated into the Final Approach Spacing Tool (FAST) in the Center-TRACON Automation System (CTAS) developed at NASA-Ames Research Center. FAST simulations have been conducted over three years involving full-proficiency, level five air traffic controllers from around the United States. From these simulations an algorithm, called Spatial Constraint Satisfaction, has been designed, coded, undergone testing, and soon will begin field evaluation at the Dallas-Fort Worth and Denver International airport facilities. The purpose of this new design is an attempt to show that the generation of efficient and conflict free aircraft arrival plans at the runway does not guarantee an operationally acceptable arrival plan upstream from the runway -information encompassing the entire arrival airspace must be used in order to create an acceptable aircraft arrival plan. This new design includes functions available previously but additionally includes necessary representations of controller preferences and workload, operationally required amounts of extra separation, and integrates aircraft conflict resolution. As a result, the Spatial Constraint Satisfaction algorithm produces an optimized aircraft arrival plan that is more acceptable in terms of arrival procedures and air traffic controller workload. This paper discusses the current Air Traffic Control arrival planning procedures, previous work in this field, the design of the Spatial Constraint Satisfaction algorithm, and the results of recent evaluations of the algorithm.

  20. Aeroelastic Loads Modeling for Composite Aircraft Design Support

    NARCIS (Netherlands)

    Baluch, H.A.

    2009-01-01

    With regard to the simulation of structural vibrations and consequent aeroelastic loads in aircraft components, the use of elastic axis e.a as reference of vibrations is quite common. The e.a decouples the bending and torsion degrees of freedom (D.o.F) during the dynamic analysis. The use of the e.a

  1. Aeroelastic Loads Modeling for Composite Aircraft Design Support

    NARCIS (Netherlands)

    Baluch, H.A.

    2009-01-01

    With regard to the simulation of structural vibrations and consequent aeroelastic loads in aircraft components, the use of elastic axis e.a as reference of vibrations is quite common. The e.a decouples the bending and torsion degrees of freedom (D.o.F) during the dynamic analysis. The use of the e.a

  2. Assessment of the thermal environment in an aircraft cabin

    DEFF Research Database (Denmark)

    Ingers, S.; Melikov, Arsen Krikor

    2004-01-01

    A full-scale section of a flight cabin with 21 seats was used to study the thermal environment in aircraft under laboratory conditions. Fourteen heated cylinders and two thermal manikins were used to simulate the heat load, the buoyancy flow and the flow obstruction from passengers in the cabin...

  3. Experimental research on photocatalytic oxidation air purification technology applied to aircraft cabins

    DEFF Research Database (Denmark)

    Sun, Yuexia; Fang, Lei; Wyon, David Peter

    2008-01-01

    The experiment presented in this report was performed in a simulated aircraft cabin to evaluate the air cleaning effects of two air purification devices that used photocatalytic oxidation (PCO) technology. Objective physical, chemical and physiological measurements and subjective human assessments...

  4. Exploring Surgeons' Perceptions of the Role of Simulation in Surgical Education: A Needs Assessment

    Directory of Open Access Journals (Sweden)

    Marcia Clark

    2011-11-01

    Full Text Available Introduction: The last two decades have seen the adoption of simulation-based surgical education in various disciplines. The current study’s goal was to perform a needs assessment using the results to inform future curricular planning and needs of surgeons and learners. Methods: A survey was distributed to 26 surgeon educators and interviews were conducted with 8 of these surgeons.  Analysis of survey results included reliability and descriptive statistics. Interviews were analyzed for thematic content with a constant comparison technique, developing coding and categorization of themes. Results: The survey response rate was 81%. The inter-item reliability, according to Cronbach’s alpha was 0.81 with strongest agreement for statements related to learning new skills, training new residents and the positive impact on patient safety and learning.   There was less strong agreement for maintenance of skills, improving team functioning and reducing teaching in the operating room. Interview results confirmed those themes from the survey and highlighted inconsistencies for identified perceived barriers and a focus on acquisition of skills only.  Interview responses specified concerns with integrating simulation into existing curricula and the need for more evaluation as a robust educational strategy. Conclusion: The findings were summarized in four themes: 1 use of simulation, 2 integration into curriculum, 3 leadership, and 4 understanding gaps in simulation use. This study exemplifies a mixed-methods approach to planning a surgical simulation program through a general needs assessment.

  5. Establishing a safe container for learning in simulation: the role of the presimulation briefing.

    Science.gov (United States)

    Rudolph, Jenny W; Raemer, Daniel B; Simon, Robert

    2014-12-01

    Summary statement: In the absence of theoretical or empirical agreement on how to establish and maintain engagement in instructor-led health care simulation debriefings, we organize a set of promising practices we have identified in closely related fields and our own work. We argue that certain practices create a psychologically safe context for learning, a so-called safe container. Establishing a safe container, in turn, allows learners to engage actively in simulation plus debriefings despite possible disruptions to that engagement such as unrealistic aspects of the simulation, potential threats to their professional identity, or frank discussion of mistakes. Establishing a psychologically safe context includes the practices of (1) clarifying expectations, (2) establishing a "fiction contract" with participants, (3) attending to logistic details, and (4) declaring and enacting a commitment to respecting learners and concern for their psychological safety. As instructors collaborate with learners to perform these practices, consistency between what instructors say and do may also impact learners' engagement.

  6. The critical role of the routing scheme in simulating peak river discharge in global hydrological models

    Science.gov (United States)

    Zhao, Fang; Veldkamp, Ted I. E.; Frieler, Katja; Schewe, Jacob; Ostberg, Sebastian; Willner, Sven; Schauberger, Bernhard; Gosling, Simon N.; Müller Schmied, Hannes; Portmann, Felix T.; Leng, Gobias; Huang, Maoyi; Liu, Xingcai; Tang, Qiuhong; Hanasaki, Naota; Biemans, Hester; Gerten, Dieter; Satoh, Yusuke; Pokhrel, Yadu; Stacke, Tobias; Ciais, Philippe; Chang, Jinfeng; Ducharne, Agnes; Guimberteau, Matthieu; Wada, Yoshihide; Kim, Hyungjun; Yamazaki, Dai

    2017-07-01

    Global hydrological models (GHMs) have been applied to assess global flood hazards, but their capacity to capture the timing and amplitude of peak river discharge—which is crucial in flood simulations—has traditionally not been the focus of examination. Here we evaluate to what degree the choice of river routing scheme affects simulations of peak discharge and may help to provide better agreement with observations. To this end we use runoff and discharge simulations of nine GHMs forced by observational climate data (1971-2010) within the ISIMIP2a project. The runoff simulations were used as input for the global river routing model CaMa-Flood. The simulated daily discharge was compared to the discharge generated by each GHM using its native river routing scheme. For each GHM both versions of simulated discharge were compared to monthly and daily discharge observations from 1701 GRDC stations as a benchmark. CaMa-Flood routing shows a general reduction of peak river discharge and a delay of about two to three weeks in its occurrence, likely induced by the buffering capacity of floodplain reservoirs. For a majority of river basins, discharge produced by CaMa-Flood resulted in a better agreement with observations. In particular, maximum daily discharge was adjusted, with a multi-model averaged reduction in bias over about 2/3 of the analysed basin area. The increase in agreement was obtained in both managed and near-natural basins. Overall, this study demonstrates the importance of routing scheme choice in peak discharge simulation, where CaMa-Flood routing accounts for floodplain storage and backwater effects that are not represented in most GHMs. Our study provides important hints that an explicit parameterisation of these processes may be essential in future impact studies.

  7. An Aircraft Navigation System Fault Diagnosis Method Based on Optimized Neural Network Algorithm

    Institute of Scientific and Technical Information of China (English)

    Jean-dedieu Weyepe

    2014-01-01

    Air data and inertial reference system (ADIRS) is one of the complex sub-system in the aircraft navigation system and it plays an important role into the flight safety of the aircraft. This paper propose an optimize neural network algorithm which is a combination of neural network and ant colony algorithm to improve efficiency of maintenance engineer job task.

  8. Commercial aircraft composite technology

    CERN Document Server

    Breuer, Ulf Paul

    2016-01-01

    This book is based on lectures held at the faculty of mechanical engineering at the Technical University of Kaiserslautern. The focus is on the central theme of societies overall aircraft requirements to specific material requirements and highlights the most important advantages and challenges of carbon fiber reinforced plastics (CFRP) compared to conventional materials. As it is fundamental to decide on the right material at the right place early on the main activities and milestones of the development and certification process and the systematic of defining clear requirements are discussed. The process of material qualification - verifying material requirements is explained in detail. All state-of-the-art composite manufacturing technologies are described, including changes and complemented by examples, and their improvement potential for future applications is discussed. Tangible case studies of high lift and wing structures emphasize the specific advantages and challenges of composite technology. Finally,...

  9. Aircraft control system

    Science.gov (United States)

    Lisoski, Derek L. (Inventor); Kendall, Greg T. (Inventor)

    2007-01-01

    A solar rechargeable, long-duration, span-loaded flying wing, having no fuselage or rudder. Having a two-hundred foot wingspan that mounts photovoltaic cells on most all of the wing's top surface, the aircraft uses only differential thrust of its eight propellers to turn, pitch and yaw. The wing is configured to deform under flight loads to position the propellers such that the control can be achieved. Each of five segments of the wing has one or more motors and photovoltaic arrays, and produces its own lift independent of the other segments, to avoid loading them. Five two-sided photovoltaic arrays, in all, are mounted on the wing, and receive photovoltaic energy both incident on top of the wing, and which is incident also from below, through a bottom, transparent surface.

  10. Role of dissolved salts in thermophoresis of DNA: lattice-Boltzmann-based simulations.

    Science.gov (United States)

    Hammack, Audrey; Chen, Yeng-Long; Pearce, Jennifer Kreft

    2011-03-01

    We use a lattice Boltzmann based Brownian dynamics simulation to investigate the dependence of DNA thermophoresis on its interaction with dissolved salts. We find the thermal diffusion coefficient D{T} depends on the molecule size, in contrast with previous simulations without electrostatics. The measured S{T} also depends on the Debye length. This suggests thermophoresis of DNA is influenced by the electrostatic interactions between the polymer beads and the salt ions. However, when electrostatic forces are weak, DNA thermophoresis is not found, suggesting that other repulsive forces such as the excluded volume force prevent thermal migration.

  11. Aircraft recognition and pose estimation

    Science.gov (United States)

    Hmam, Hatem; Kim, Jijoong

    2000-05-01

    This work presents a geometry based vision system for aircraft recognition and pose estimation using single images. Pose estimation improves the tracking performance of guided weapons with imaging seekers, and is useful in estimating target manoeuvres and aim-point selection required in the terminal phase of missile engagements. After edge detection and straight-line extraction, a hierarchy of geometric reasoning algorithms is applied to form line clusters (or groupings) for image interpretation. Assuming a scaled orthographic projection and coplanar wings, lateral symmetry inherent in the airframe provides additional constraints to further reject spurious line clusters. Clusters that accidentally pass all previous tests are checked against the original image and are discarded. Valid line clusters are then used to deduce aircraft viewing angles. By observing that the leading edges of wings of a number of aircraft of interest are within 45 to 65 degrees from the symmetry axis, a bounded range of aircraft viewing angles can be found. This generic property offers the advantage of not requiring the storage of complete aircraft models viewed from all aspects, and can handle aircraft with flexible wings (e.g. F111). Several aircraft images associated with various spectral bands (i.e. visible and infra-red) are finally used to evaluate the system's performance.

  12. The Role of Negative Reinforcement in Infant Caregiving: An Experimental Simulation

    Science.gov (United States)

    Thompson, Rachel H.; Bruzek, Jennifer L.; Cotnoir-Bichelman, Nicole M.

    2011-01-01

    We observed 11 undergraduates in an experiment designed to simulate infant caregiving. In negative reinforcement conditions experienced by all participants, a targeted caregiving response (e.g., rocking a baby doll) produced escape from, and avoidance of, a recorded infant cry. Nine participants' caregiving was shown to be controlled by this…

  13. The Role of Visual Occlusion in Altitude Maintenance during Simulated Flight

    Science.gov (United States)

    Gray, R.; Geri, G. A.; Akhtar, S. C.; Covas, C. M.

    2008-01-01

    The use of visual occlusion as a cue to altitude maintenance in low-altitude flight (LAF) was investigated. The extent to which the ground surface is occluded by 3-D objects varies with altitude and depends on the height, radius, and density of the objects. Participants attempted to maintain a constant altitude during simulated flight over an…

  14. Dynamic Modeling Accuracy Dependence on Errors in Sensor Measurements, Mass Properties, and Aircraft Geometry

    Science.gov (United States)

    Grauer, Jared A.; Morelli, Eugene A.

    2013-01-01

    A nonlinear simulation of the NASA Generic Transport Model was used to investigate the effects of errors in sensor measurements, mass properties, and aircraft geometry on the accuracy of dynamic models identified from flight data. Measurements from a typical system identification maneuver were systematically and progressively deteriorated and then used to estimate stability and control derivatives within a Monte Carlo analysis. Based on the results, recommendations were provided for maximum allowable errors in sensor measurements, mass properties, and aircraft geometry to achieve desired levels of dynamic modeling accuracy. Results using other flight conditions, parameter estimation methods, and a full-scale F-16 nonlinear aircraft simulation were compared with these recommendations.

  15. Integrated Control with Structural Feedback to Enable Lightweight Aircraft

    Science.gov (United States)

    Taylor, Brian R.

    2011-01-01

    This presentation for the Fundamental Aeronautics Program Technical Conference covers the benefits of active structural control, related research areas, and focuses on the use of optimal control allocation for the prevention of critical loads. Active control of lightweight structures has the potential to reduce aircraft weight and fuel burn. Sensor, control law, materials, control effector, and system level research will be necessary to enable active control of lightweight structures. Optimal control allocation with structural feedback has been shown in simulation to be feasible in preventing critical loads and is one example of a control law to enable future lightweight aircraft.

  16. Assessment of the thermal environment in an aircraft cabin

    DEFF Research Database (Denmark)

    Ingers, S.; Melikov, Arsen Krikor

    2004-01-01

    A full-scale section of a flight cabin with 21 seats was used to study the thermal environment in aircraft under laboratory conditions. Fourteen heated cylinders and two thermal manikins were used to simulate the heat load, the buoyancy flow and the flow obstruction from passengers in the cabin...... equivalent temperature, up to 5.8°C, was identified in the outer seats. The results reveal that in an aircraft cabin, passengers in the outer seats may be exposed to thermal asymmetry and draught and may not find the thermal environment acceptable if the ventilation air is not properly supplied....

  17. [Effect of alcohol intake on the ability to pilot aircraft].

    Science.gov (United States)

    Ushakov, I B; Egorov, S V

    1996-01-01

    During the initial 4 hours after alcohol intake at a dose of 1.9 g/kg aircraft operators displayed disturbances in the psychic processes and functions responsible for each (from information reception and processing up to decision-making and building-up the controlling actions) structural elements in their activity resulting in considerable limitation or a complete failure to pilot aircraft. Main disorders included inability to correctly analyse flight situation and loss of skills to automatically control simulator, a sudden depletion of psychophysiological reserves and deterioration of operator's reliability. Less elaborated professional skills appear to be the most vulnerable.

  18. Dynamic decoupling nonlinear control method for aircraft gust alleviation

    Science.gov (United States)

    Lv, Yang; Wan, Xiaopeng; Li, Aijun

    2008-10-01

    A dynamic decoupling nonlinear control method for MIMO system is presented in this paper. The dynamic inversion method is used to decouple the multivariable system. The nonlinear control method is used to overcome the poor decoupling effect when the system model is inaccurate. The nonlinear control method has correcting function and is expressed in analytic form, it is easy to adjust the parameters of the controller and optimize the design of the control system. The method is used to design vertical transition mode of active control aircraft for gust alleviation. Simulation results show that the designed vertical transition mode improves the gust alleviation effect about 34% comparing with the normal aircraft.

  19. Aircraft Attitude/Heading Estimation Using a Dipole Triad Antenna

    Directory of Open Access Journals (Sweden)

    He Min

    2013-06-01

    Full Text Available This paper performs aircraft attitude/heading estimation using an airborne dipole triad antenna. The signal model is given with the parameters such as the wave Direction Of Arrival (DOA and state of polarization. The algorithms for estimating the source DOA and electric ellipse orientation angle are presented along with their statistical performance analysis. From these parameters, the aircraft gesture angles about pitching, yawing, and rolling, which are needed by autopilot, are produced. Simulation results validate the proposed algorithm’s efficacy.

  20. 36 CFR 327.4 - Aircraft.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Aircraft. 327.4 Section 327.4... Aircraft. (a) This section pertains to all aircraft including, but not limited to, airplanes, seaplanes, helicopters, ultra-light aircraft, motorized hang gliders, hot air balloons, any non-powered flight devices or...