Sample records for aircraft design

  1. Aircraft Design (United States)

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


    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.



    RAHMATI, Sadegh; GHASED, Amir


    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 ...

  3. Stochastic Methods for Aircraft Design (United States)

    Pelz, Richard B.; Ogot, Madara


    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.

  4. Advanced Aerostructural Optimization Techniques for Aircraft Design


    Yingtao Zuo; Pingjian Chen; Lin Fu; Zhenghong Gao; Gang Chen


    Traditional coupled aerostructural design optimization (ASDO) of aircraft based on high-fidelity models is computationally expensive and inefficient. To improve the efficiency, the key is to predict aerostructural performance of the aircraft efficiently. The cruise shape of the aircraft is parameterized and optimized in this paper, and a methodology named reverse iteration of structural model (RISM) is adopted to get the aerostructural performance of cruise shape efficiently. A new mathematic...

  5. Design Methods and Optimization for Morphing Aircraft (United States)

    Crossley, William A.


    This report provides a summary of accomplishments made during this research effort. The major accomplishments are in three areas. The first is the use of a multiobjective optimization strategy to help identify potential morphing features that uses an existing aircraft sizing code to predict the weight, size and performance of several fixed-geometry aircraft that are Pareto-optimal based upon on two competing aircraft performance objectives. The second area has been titled morphing as an independent variable and formulates the sizing of a morphing aircraft as an optimization problem in which the amount of geometric morphing for various aircraft parameters are included as design variables. This second effort consumed most of the overall effort on the project. The third area involved a more detailed sizing study of a commercial transport aircraft that would incorporate a morphing wing to possibly enable transatlantic point-to-point passenger service.

  6. Aircraft systems design methodology and dispatch reliability prediction


    Bineid, Mansour


    Aircraft despatch reliability was the main subject of this research in the wider content of aircraft reliability. The factors effecting dispatch reliability, aircraft delay, causes of aircraft delays, and aircraft delay costs and magnitudes were examined. Delay cost elements and aircraft delay scenarios were also studied. It concluded that aircraft dispatch reliability is affected by technical and non-technical factors, and that the former are under the designer's control. It showed that ...

  7. Aircraft System Design and Integration

    Directory of Open Access Journals (Sweden)

    D. P. Coldbeck


    Full Text Available In the 1980's the British aircraft industry changed its approach to the management of projects from a system where a project office would manage a project and rely on a series of specialist departments to support them to a more process oriented method, using systems engineering models, whose most outwardly visible signs were the introduction of multidisciplinary product teams. One of the problems with the old method was that the individual departments often had different priorities and projects would get uneven support. The change in the system was only made possible for complex designs by the electronic distribution of data giving instantaneous access to all involved in the project. In 1997 the Defence and Aerospace Foresight Panel emphasised the need for a system engineering approach if British industry was to remain competitive. The Royal Academy of Engineering recognised that the change in working practices also changed what was required of a chartered engineer and redefined their requirements in 1997 [1]. The result of this is that engineering degree courses are now judged against new criteria with more emphasis placed on the relevance to industry rather than on purely academic content. At the University of Glasgow it was realized that the students ought to be made aware of current working practices and that there ought to be a review to ensure that the degrees give students the skills required by industry. It was decided to produce a one week introduction course in systems engineering for Masters of Engineering (MEng students to be taught by both university lecturers and practitioners from a range of companies in the aerospace industry with the hope of expanding the course into a module. The reaction of the students was favourable in terms of the content but it seems ironic that the main criticism was that there was not enough discussion involving the students. This paper briefly describes the individual teaching modules and discusses the

  8. A computer application for parametric aircraft design (United States)

    Fraqueiro, Filipe R.; Albuquerque, Pedro F.; Gamboa, Pedro V.


    The present work describes the development and final result of a graphical user interface tailored for a mission-based parametric aircraft design optimization code which targets the preliminary design phase of unmanned aerial vehicles. This development was built from the XFLR5 open source platform and further benefits from two-dimensional aerodynamic data obtained from XFOIL. For a better understanding, the most important graphical windows are shown. In order to demonstrate the graphical user interface interaction with the aircraft designer, the results of a case study which maximizes payload are presented.

  9. Aircraft family design using enhanced collaborative optimization (United States)

    Roth, Brian Douglas

    Significant progress has been made toward the development of multidisciplinary design optimization (MDO) methods that are well-suited to practical large-scale design problems. However, opportunities exist for further progress. This thesis describes the development of enhanced collaborative optimization (ECO), a new decomposition-based MDO method. To support the development effort, the thesis offers a detailed comparison of two existing MDO methods: collaborative optimization (CO) and analytical target cascading (ATC). This aids in clarifying their function and capabilities, and it provides inspiration for the development of ECO. The ECO method offers several significant contributions. First, it enhances communication between disciplinary design teams while retaining the low-order coupling between them. Second, it provides disciplinary design teams with more authority over the design process. Third, it resolves several troubling computational inefficiencies that are associated with CO. As a result, ECO provides significant computational savings (relative to CO) for the test cases and practical design problems described in this thesis. New aircraft development projects seldom focus on a single set of mission requirements. Rather, a family of aircraft is designed, with each family member tailored to a different set of requirements. This thesis illustrates the application of decomposition-based MDO methods to aircraft family design. This represents a new application area, since MDO methods have traditionally been applied to multidisciplinary problems. ECO offers aircraft family design the same benefits that it affords to multidisciplinary design problems. Namely, it simplifies analysis integration, it provides a means to manage problem complexity, and it enables concurrent design of all family members. In support of aircraft family design, this thesis introduces a new wing structural model with sufficient fidelity to capture the tradeoffs associated with component

  10. Modeling Programs Increase Aircraft Design Safety (United States)


    Flutter may sound like a benign word when associated with a flag in a breeze, a butterfly, or seaweed in an ocean current. When used in the context of aerodynamics, however, it describes a highly dangerous, potentially deadly condition. Consider the case of the Lockheed L-188 Electra Turboprop, an airliner that first took to the skies in 1957. Two years later, an Electra plummeted to the ground en route from Houston to Dallas. Within another year, a second Electra crashed. In both cases, all crew and passengers died. Lockheed engineers were at a loss as to why the planes wings were tearing off in midair. For an answer, the company turned to NASA s Transonic Dynamics Tunnel (TDT) at Langley Research Center. At the time, the newly renovated wind tunnel offered engineers the capability of testing aeroelastic qualities in aircraft flying at transonic speeds near or just below the speed of sound. (Aeroelasticity is the interaction between aerodynamic forces and the structural dynamics of an aircraft or other structure.) Through round-the-clock testing in the TDT, NASA and industry researchers discovered the cause: flutter. Flutter occurs when aerodynamic forces acting on a wing cause it to vibrate. As the aircraft moves faster, certain conditions can cause that vibration to multiply and feed off itself, building to greater amplitudes until the flutter causes severe damage or even the destruction of the aircraft. Flutter can impact other structures as well. Famous film footage of the Tacoma Narrows Bridge in Washington in 1940 shows the main span of the bridge collapsing after strong winds generated powerful flutter forces. In the Electra s case, faulty engine mounts allowed a type of flutter known as whirl flutter, generated by the spinning propellers, to transfer to the wings, causing them to vibrate violently enough to tear off. Thanks to the NASA testing, Lockheed was able to correct the Electra s design flaws that led to the flutter conditions and return the

  11. Structural analysis at aircraft conceptual design stage (United States)

    Mansouri, Reza

    In the past 50 years, computers have helped by augmenting human efforts with tremendous pace. The aircraft industry is not an exception. Aircraft industry is more than ever dependent on computing because of a high level of complexity and the increasing need for excellence to survive a highly competitive marketplace. Designers choose computers to perform almost every analysis task. But while doing so, existing effective, accurate and easy to use classical analytical methods are often forgotten, which can be very useful especially in the early phases of the aircraft design where concept generation and evaluation demands physical visibility of design parameters to make decisions [39, 2004]. Structural analysis methods have been used by human beings since the very early civilization. Centuries before computers were invented; the pyramids were designed and constructed by Egyptians around 2000 B.C, the Parthenon was built by the Greeks, around 240 B.C, Dujiangyan was built by the Chinese. Persepolis, Hagia Sophia, Taj Mahal, Eiffel tower are only few more examples of historical buildings, bridges and monuments that were constructed before we had any advancement made in computer aided engineering. Aircraft industry is no exception either. In the first half of the 20th century, engineers used classical method and designed civil transport aircraft such as Ford Tri Motor (1926), Lockheed Vega (1927), Lockheed 9 Orion (1931), Douglas DC-3 (1935), Douglas DC-4/C-54 Skymaster (1938), Boeing 307 (1938) and Boeing 314 Clipper (1939) and managed to become airborne without difficulty. Evidencing, while advanced numerical methods such as the finite element analysis is one of the most effective structural analysis methods; classical structural analysis methods can also be as useful especially during the early phase of a fixed wing aircraft design where major decisions are made and concept generation and evaluation demands physical visibility of design parameters to make decisions

  12. Conceptual design and optimization methodology for box wing aircraft


    Jemitola, Paul Olugbeji


    A conceptual design optimization methodology was developed for a medium range box wing aircraft. A baseline conventional cantilever wing aircraft designed for the same mis- sion and payload was also optimized alongside a baseline box wing aircraft. An empirical formula for the mass estimation of the fore and aft wings of the box wing aircraft was derived by relating conventional cantilever wings to box wing aircraft wings. The results indicate that the fore and aft wings would ...

  13. Aircraft Design Analysis, CFD And Manufacturing

    Directory of Open Access Journals (Sweden)

    Haifa El-Sadi


    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.

  14. 50 years of transonic aircraft design (United States)

    Jameson, Antony; Ou, Kui


    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.

  15. Multimission Aircraft Design Study, Payload (United States)


    iterated several times up to the level time allowed. 1.4 Scope It is necessary to recall that the backgrounds of the Systems Engineering Design Team...landing options are as wheels, skids, parachutes, airbags and none; that is, letting it fly forever or crash. Trade studies should be done in order to

  16. Flight Control Design for a Tailless Aircraft Using Eigenstructure Assignment


    Clara Nieto-Wire; Kenneth Sobel


    We apply eigenstructure assignment to the design of a flight control system for a wind tunnel model of a tailless aircraft. The aircraft, known as the innovative control effectors (ICEs) aircraft, has unconventional control surfaces plus pitch and yaw thrust vectoring. We linearize the aircraft in straight and level flight at an altitude of 15,000 feet and Mach number 0.4. Then, we separately design flight control systems for the longitudinal and lateral dynamics. We use a control allocation ...

  17. Aircraft Conceptual Design Using Vehicle Sketch Pad (United States)

    Fredericks, William J.; Antcliff, Kevin R.; Costa, Guillermo; Deshpande, Nachiket; Moore, Mark D.; Miguel, Edric A. San; Snyder, Alison N.


    Vehicle Sketch Pad (VSP) is a parametric geometry modeling tool that is intended for use in the conceptual design of aircraft. The intent of this software is to rapidly model aircraft configurations without expending the expertise and time that is typically required for modeling with traditional Computer Aided Design (CAD) packages. VSP accomplishes this by using parametrically defined components, such as a wing that is defined by span, area, sweep, taper ratio, thickness to cord, and so on. During this phase of frequent design builds, changes to the model can be rapidly visualized along with the internal volumetric layout. Using this geometry-based approach, parameters such as wetted areas and cord lengths can be easily extracted for rapid external performance analyses, such as a parasite drag buildup. At the completion of the conceptual design phase, VSP can export its geometry to higher fidelity tools. This geometry tool was developed by NASA and is freely available to U.S. companies and universities. It has become integral to conceptual design in the Aeronautics Systems Analysis Branch (ASAB) here at NASA Langley Research Center and is currently being used at over 100 universities, aerospace companies, and other government agencies. This paper focuses on the use of VSP in recent NASA conceptual design studies to facilitate geometry-centered design methodology. Such a process is shown to promote greater levels of creativity, more rapid assessment of critical design issues, and improved ability to quickly interact with higher order analyses. A number of VSP vehicle model examples are compared to CAD-based conceptual design, from a designer perspective; comparisons are also made of the time and expertise required to build the geometry representations as well.

  18. Advanced Aerostructural Optimization Techniques for Aircraft Design

    Directory of Open Access Journals (Sweden)

    Yingtao Zuo


    Full Text Available Traditional coupled aerostructural design optimization (ASDO of aircraft based on high-fidelity models is computationally expensive and inefficient. To improve the efficiency, the key is to predict aerostructural performance of the aircraft efficiently. The cruise shape of the aircraft is parameterized and optimized in this paper, and a methodology named reverse iteration of structural model (RISM is adopted to get the aerostructural performance of cruise shape efficiently. A new mathematical explanation of RISM is presented in this paper. The efficiency of RISM can be improved by four times compared with traditional static aeroelastic analysis. General purpose computing on graphical processing units (GPGPU is adopted to accelerate the RISM further, and GPU-accelerated RISM is constructed. The efficiency of GPU-accelerated RISM can be raised by about 239 times compared with that of the loosely coupled aeroelastic analysis. Test shows that the fidelity of GPU-accelerated RISM is high enough for optimization. Optimization framework based on Kriging model is constructed. The efficiency of the proposed optimization system can be improved greatly with the aid of GPU-accelerated RISM. An unmanned aerial vehicle (UAV is optimized using this framework and the range is improved by 4.67% after optimization, which shows effectiveness and efficiency of this framework.

  19. Circulation control STOL aircraft design aspects (United States)

    Loth, John L.


    Since Davidson patented Circulation Control Airfoils in 1960, there have been only 2 aircraft designed and flown with circulation control (CC). Designing with CC is complex for the following reasons: the relation between lift increase and blowing momentum is nonlinear; for good cruise performance one must change the wing geometry in flight from a round to a sharp trailing edge. The bleed air from the propulsion engines or an auxiliary compressor, must be used efficiently. In designing with CC, the propulsion and control aspects are just as important as aerodynamics. These design aspects were examined and linearized equations are presented in order to facilitate a preliminary analysis of the performance potential of CC. The thrust and lift requirements for takeoff make the calculated runway length very sensitive to the bleed air ratio. Thrust vectoring improves performance and can offset nose down pitching moments. The choice of blowing jet to free stream velocity ratio determines the efficiency of applying bleed air power.

  20. A Knowledge-based and Extensible Aircraft Conceptual Design Environment

    Institute of Scientific and Technical Information of China (English)

    FENG Haocheng; LUO Mingqiang; LIU Hu; WU Zhe


    Design knowledge and experience are the bases to carry out aircraft conceptual design tasks due to the high complexity and integration of the tasks during this phase.When carrying out the same task,different designers may need individual strategies to fulfill their own demands.A knowledge-based and extensible method in building aircraft conceptual design systems is studied considering the above requirements.Based on the theory,a knowledge-based aircraft conceptual design environment,called knowledge-based and extensible aircraft conceptual design environment (KEACDE) with open architecture,is built as to enable designers to wrap add-on extensions and make their own aircraft conceptual design systems.The architecture,characteristics and other design and development aspects of KEACDE are discussed.A civil airplane conceptual design system (CACDS) is achieved using KEACDE.Finally,a civil airplane design case is presented to demonstrate the usability and effectiveness of this environment.

  1. Innovative Aircraft Design – Options for a New Medium Range Aircraft


    Scholz, Dieter


    Task was to find an innovative aircraft design for a new medium range aircraft. The aircraft design methodology is based on equations (in contrast to numeric methods) and formal optimization with a genetic algorithm called differential evolution. Airbus has postponed an all-new A320 to 2025 or even 2030. This allows including also unconventional configurations into the search. Economic requirements are extreme: 25 % to 40 % reduction in fuel consumption, 35 % reduction in Cash Operating Costs...

  2. A historical perspective of aircrew systems effects on aircraft design


    Bauer, David O.


    Approved for public release; distribution in unlimited. The design of the aircrew workstation often has not been an orderly part of the overall aircraft design process but rather of much lower priority than the integration of the airframe and powerplant. However, the true test of the aircraft is how well the aircrew can use the aircraft for mission performance. NAVAIR has been seeking the establishment of an Aircrew Centered System Design discipline, to be addressed as an integral part of ...

  3. Aircraft Structural Analysis, Design Optimization, and Manufacturing Tool Integration Project (United States)

    National Aeronautics and Space Administration — Innovative research is proposed in integrating fundamental aircraft design processes with an emphasis on composite structures. Efficient, lightweight composite...

  4. Conceptual design of high speed supersonic aircraft: A brief review on SR-71 (Blackbird) aircraft (United States)

    Xue, Hui; Khawaja, H.; Moatamedi, M.


    The paper presents the conceptual design of high-speed supersonic aircraft. The study focuses on SR-71 (Blackbird) aircraft. The input to the conceptual design is a mission profile. Mission profile is a flight profile of the aircraft defined by the customer. This paper gives the SR-71 aircraft mission profile specified by US air force. Mission profile helps in defining the attributes the aircraft such as wing profile, vertical tail configuration, propulsion system, etc. Wing profile and vertical tail configurations have direct impact on lift, drag, stability, performance and maneuverability of the aircraft. A propulsion system directly influences the performance of the aircraft. By combining the wing profile and the propulsion system, two important parameters, known as wing loading and thrust to weight ratio can be calculated. In this work, conceptual design procedure given by D. P. Raymer (AIAA Educational Series) is applied to calculate wing loading and thrust to weight ratio. The calculated values are compared against the actual values of the SR-71 aircraft. Results indicates that the values are in agreement with the trend of developments in aviation.

  5. Aircraft conceptual design modelling incorporating reliability and maintainability predictions


    Vaziry-Zanjany , Mohammad Ali (F)


    A computer assisted conceptual aircraft design program has been developed (CACAD). It has an optimisation capability, with extensive break-down in maintenance costs. CACAD's aim is to optimise the size, and configurations of turbofan-powered transport aircraft. A methodology was developed to enhance the reliability of current aircraft systems, and was applied to avionics systems. R&M models of thermal management were developed and linked with avionics failure rate and its ma...

  6. Ergonomic analysis for a regional aircraft interior design.


    Flavia Renata Dantas Alves Silva


    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...

  7. Research on Data Distribution Service for Aircraft Collaborative Design System

    Directory of Open Access Journals (Sweden)

    Huaxing Bian


    Full Text Available Aircraft designing is a complex, multi-disciplinary process, while the applications are separated from each other due to their particular design and analysis tools. The separated applications are unable to meet the collaborative designing requirements. One of the fundamental problems in Aircraft Collaborative Design System is that how to make each subsystem collaborate. The known solutions, using Existing middlewares to unify data formats, are not reliable due to the tightly coupled architecture, poor portability and reusability, large update latency, etc. To solve this problem, the paper propose that apply DDS into Aircraft Collaborative Design System, and give the solution that how to use open source projects OpenDDS in Aircraft Collaborative Design System.

  8. Performance Evaluation Method for Dissimilar Aircraft Designs (United States)

    Walker, H. J.


    A rationale is presented for using the square of the wingspan rather than the wing reference area as a basis for nondimensional comparisons of the aerodynamic and performance characteristics of aircraft that differ substantially in planform and loading. Working relationships are developed and illustrated through application to several categories of aircraft covering a range of Mach numbers from 0.60 to 2.00. For each application, direct comparisons of drag polars, lift-to-drag ratios, and maneuverability are shown for both nondimensional systems. The inaccuracies that may arise in the determination of aerodynamic efficiency based on reference area are noted. Span loading is introduced independently in comparing the combined effects of loading and aerodynamic efficiency on overall performance. Performance comparisons are made for the NACA research aircraft, lifting bodies, century-series fighter aircraft, F-111A aircraft with conventional and supercritical wings, and a group of supersonic aircraft including the B-58 and XB-70 bomber aircraft. An idealized configuration is included in each category to serve as a standard for comparing overall efficiency.

  9. Backstepping Designs for Aircraft Control - What is there to Gain?


    Härkegård, Ola


    Aircraft flight control design is traditionally based on linear control theory, due to the existing wealth of tools for linear design and analysis. However, in order to achieve tactical advantages, modern fighter aircraft strive towards performing maneuvers outside the region where the dynamics of flight are linear, and the need for nonlinear tools arises. In this paper, backstepping is proposed as a possible framework for nonlinear flight control design. Its capabilities of handling five maj...

  10. Research of low boom and low drag supersonic aircraft design


    Feng Xiaoqiang; Li Zhanke; Song Bifeng


    Sonic boom reduction will be an issue of utmost importance in future supersonic transport, due to strong regulations on acoustic nuisance. The paper describes a new multi-objective optimization method for supersonic aircraft design. The method is developed by coupling Seebass–George–Darden (SGD) inverse design method and multi-objective genetic algorithm. Based on the method, different codes are developed. Using a computational architecture, a conceptual supersonic aircraft design environment...

  11. Review of evolving trends in blended wing body aircraft design (United States)

    Okonkwo, Paul; Smith, Howard


    The desire to produce environmentally friendly aircraft that is aerodynamically efficient and capable of conveying large number of passengers over long ranges at reduced direct operating cost led aircraft designers to develop the Blended Wing Body (BWB) aircraft concept. The BWB aircraft represents a paradigm shift in the design of aircraft. The design provides aerodynamics and environmental benefits and is suitable for the integration of advanced systems and concepts like laminar flow technology, jet flaps and distributed propulsion. However, despite these benefits, the BWB is yet to be developed for commercial air transport due to several challenges. This paper reviews emerging trends in BWB aircraft design highlighting design challenges that have hindered the development of a BWB passenger transport aircraft. The study finds that in order to harness the advantages and reduce the deficiencies of a tightly coupled configuration like the BWB, a multidisciplinary design synthesis optimisation should be conducted with good handling and ride quality as objective functions within acceptable direct operating cost and noise bounds.

  12. Preliminary Design of a LSA Aircraft Using Wind Tunnel Tests

    Directory of Open Access Journals (Sweden)

    Norbert ANGI


    Full Text Available This paper presents preliminary results concerning the design and aerodynamic calculations of a light sport aircraft (LSA. These were performed for a new lightweight, low cost, low fuel consumption and long-range aircraft. The design process was based on specific software tools as Advanced Aircraft Analysis (AAA, XFlr 5 aerodynamic and dynamic stability analysis, and Catia design, according to CS-LSA requirements. The calculations were accomplished by a series of tests performed in the wind tunnel in order to assess experimentally the aerodynamic characteristics of the airplane.

  13. Investigation and design of a C-Wing passenger aircraft


    Karan BIKKANNAVAR; Scholz, Dieter


    A novel nonplanar wing concept called C-Wing is studied and implemented on a commercial aircraft to reduce induced drag which has a significant effect on fuel consumption. A preliminary sizing method which employs an optimization algorithm is utilized. The Airbus A320 aircraft is used as a reference aircraft to evaluate design parameters and to investigate the C-Wing design potential beyond current wing tip designs. An increase in aspect ratio due to wing area reduction at 36m span results in...

  14. Design of heavy lift cargo aircraft (United States)

    National Aeronautics and Space Administration — This is the bird of the skies of the future. The heavy lift cargo aircraft which is currently being developed by me has twice the payload capacity of an Antonov...

  15. Aircraft energy efficiency laminar flow control wing design study (United States)

    Bonner, T. F., Jr.; Pride, J. D., Jr.; Fernald, W. W.


    An engineering design study was performed in which laminar flow control (LFC) was integrated into the wing of a commercial passenger transport aircraft. A baseline aircraft configuration was selected and the wing geometry was defined. The LFC system, with suction slots, ducting, and suction pumps was integrated with the wing structure. The use of standard aluminum technology and advanced superplastic formed diffusion bonded titanium technology was evaluated. The results of the design study show that the LFC system can be integrated with the wing structure to provide a structurally and aerodynamically efficient wing for a commercial transport aircraft.

  16. Riveted Lap Joints in Aircraft Fuselage Design, Analysis and Properties

    CERN Document Server

    Skorupa, Andrzej


    Fatigue of the pressurized fuselages of transport aircraft is a significant problem all builders and users of aircraft have to cope with for reasons associated with assuring a sufficient lifetime and safety, and formulating adequate inspection procedures. These aspects are all addressed in various formal protocols for creating and maintaining airworthiness, including damage tolerance considerations. In most transport aircraft, fatigue occurs in lap joints, sometimes leading to circumstances that threaten safety in critical ways. The problem of fatigue of lap joints has been considerably enlarged by the goal of extending aircraft lifetimes. Fatigue of riveted lap joints between aluminium alloy sheets, typical of the pressurized aircraft fuselage, is the major topic of the present book. The richly illustrated and well-structured chapters treat subjects such as: structural design solutions and loading conditions for fuselage skin joints; relevance of laboratory test results for simple lap joint specimens to rive...

  17. Morphing Aircraft Technology - New Shapes for Aircraft Design (United States)


    different speeds, depending on whether it is in the cruise or climb mode. Designers use camber changing flaps and water ballast to improve performance as...leading edge and trailing edge flap deflections to control camber, although imperfectly. The Mission Adaptive Wing (MAW) supercritical airfoil camber...they move from one mode of flight to the other. The disadvantage of ballast is that, like fuel, once it is gone, it is gone

  18. V/STOL tilt rotor aircraft study. Volume 2: Preliminary design of research aircraft (United States)


    A preliminary design study was conducted to establish a minimum sized, low cost V/STOL tilt-rotor research aircraft with the capability of performing proof-of-concept flight research investigations applicable to a wide range of useful military and commercial configurations. The analysis and design approach was based on state-of-the-art methods and maximum use of off-the-shelf hardware and systems to reduce development risk, procurement cost and schedules impact. The rotors to be used are of 26 foot diameter and are the same as currently under construction and test as part of NASA Tilt-Rotor Contract NAS2-6505. The aircraft has a design gross weight of 12,000 lbs. The proposed engines to be used are Lycoming T53-L-13B rated at 1550 shaft horsepower which are fully qualified. A flight test investigation is recommended which will determine the capabilities and limitations of the research aircraft.

  19. Design of a Three Surfaces R/C Aircraft Model

    Directory of Open Access Journals (Sweden)

    D. P. Coiro


    Full Text Available Design of a three lifting surfaces radio-controlled model has been carried out at Dipartimento di Progettazione Aeronautica (DPA by the authors in the last year. The model is intended to be a UAV prototype and is now under construction. The main goal of this small aircraft's design is to check the influence of the canard surface on the aircraft's aerodynamic characteristics and flight behavior, especially at high angles of attack. The aircraft model is also intended to be a flying platform to test sensors, measurement and acquisition systems for research purposes and a valid and low-cost teaching instrument for flight dynamics and flight maneuvering. The aircraft has been designed to fly with and without canard, and all problems relative to aircraft balance and stability have been carefully analyzed and solved. The innovative configuration and the mixed wooden-composite material structure has been obtained with very simple shapes and all the design is focused on realizing a low-cost model. A complete aerodynamic analysis of the configuration up to high angles of attack and a preliminary aircraft stability and performance prediction will be presented.

  20. A 174 passenger aircraft pylon design and analysis.


    Marcos Vinicius Pirrho Loureiro


    The goal of this work is to verify the pylon design of a 174 passenger aircraft. This aircraft was studied by the fourth class of Embraer's Engineer Specialization Program (PEE 4). The engine of this aircraft is located below the wing and its model is GE CFM-56. The fan size was increased in order to reach a higher air passage ratio. This pylon concept presented here was studied and adopted by the group as the better option for this type of airplane. Due to the short time allowable to this st...

  1. An economic model for evaluating high-speed aircraft designs (United States)

    Vandervelden, Alexander J. M.


    A Class 1 method for determining whether further development of a new aircraft design is desirable from all viewpoints is presented. For the manufacturer the model gives an estimate of the total cost of research and development from the preliminary design to the first production aircraft. Using Wright's law of production, one can derive the average cost per aircraft produced for a given break-even number. The model will also provide the airline with a good estimate of the direct and indirect operating costs. From the viewpoint of the passenger, the model proposes a tradeoff between ticket price and cruise speed. Finally all of these viewpoints are combined in a Comparative Aircraft Seat-kilometer Economic Index.

  2. Application of Fuzzy QFD to Aircraft Top Hierarchy Design

    Institute of Scientific and Technical Information of China (English)

    XIE Jian-xi; SONG Bi-feng; LIU Dong-xia


    In this paper, based on the Quality Function Deployment (QFD) method, the Fuzzy Quality Function Deployment (FQFD) theory and the step-by-step hierarchy structure in aircraft top decision design are studied. The fuzzy model for computing competitive factor in evaluation is presented.The decision of key technologies for improving the performance and affordability of a fixed-wing aircraft is studied using the model, and the result proves the feasibility of this model.

  3. Multidisciplinary design optimization of low-noise transport aircraft (United States)

    Leifsson, Leifur Thor

    The objective of this research is to examine how to design low-noise transport aircraft using Multidisciplinary Design Optimization (MDO). The subject is approached by designing for low-noise both implicitly and explicitly. The explicit design approach involves optimizing an aircraft while explicitly constraining the noise level. An MDO framework capable of optimizing both a cantilever wing and a Strut-Braced-Wing (SBW) aircraft was developed. The objective is to design aircraft for low-airframe-noise at the approach conditions and quantify the change in weight and performance with respect to a traditionally designed aircraft. The results show that reducing airframe noise by reducing approach speed alone, will not provide significant noise reduction without a large performance and weight penalty. Therefore, more dramatic changes to the aircraft design are needed to achieve a significant airframe noise reduction. Another study showed that the trailing-edge flap can be eliminated, as well as all the noise associated with that device, without incurring a significant weight and performance penalty. Lastly, an airframe noise analysis showed that a SBW aircraft with short fuselage-mounted landing gear could have a similar or potentially a lower airframe noise level than a comparable cantilever wing aircraft. The implicit design approach involves selecting a configuration that supports a low-noise operation, and optimizing for performance. In this study a Blended-Wing-Body (BWB) transport aircraft, with a conventional and a distributed propulsion system, was optimized for minimum take-off gross weight. The effects of distributed propulsion were studied using an MDO framework previously developed at Virginia Tech. The results show that more than two thirds of the theoretical savings of distributed propulsion are required for the BWB designs with a distributed propulsion system to have comparable gross weight as those with a conventional propulsion system. Therefore

  4. The ARCTAS aircraft mission: design and execution

    Directory of Open Access Journals (Sweden)

    D. J. Jacob


    Full Text Available The NASA Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS mission was conducted in two 3-week deployments based in Alaska (April 2008 and western Canada (June–July 2008. The goal of ARCTAS was to better understand the factors driving current changes in Arctic atmospheric composition and climate, including (1 transport of mid-latitude pollution, (2 boreal forest fires, (3 aerosol radiative forcing, and (4 chemical processes. ARCTAS involved three aircraft: a DC-8 with detailed chemical payload, a P-3 with extensive aerosol payload, and a B-200 with aerosol remote sensing instrumentation. The aircraft augmented satellite observations of Arctic atmospheric composition, in particular from the NASA A-Train, by (1 validating the data, (2 improving constraints on retrievals, (3 making correlated observations, and (4 characterizing chemical and aerosol processes. The April flights (ARCTAS-A sampled pollution plumes from all three mid-latitude continents, fire plumes from Siberia and Southeast Asia, and halogen radical events. The June-July flights (ARCTAS-B focused on boreal forest fire influences and sampled fresh fire plumes from northern Saskatchewan as well as older fire plumes from Canada, Siberia, and California. The June–July deployment was preceded by one week of flights over California sponsored by the California Air Resources Board (ARCTAS-CARB. The ARCTAS-CARB goals were to (1 improve state emission inventories for greenhouse gases and aerosols, (2 provide observations to test and improve models of ozone and aerosol pollution. Extensive sampling across southern California and the Central Valley characterized emissions from urban centers, offshore shipping lanes, agricultural crops, feedlots, industrial sources, and wildfires.

  5. Investigation and design of a C-Wing passenger aircraft

    Directory of Open Access Journals (Sweden)



    Full Text Available A novel nonplanar wing concept called C-Wing is studied and implemented on a commercial aircraft to reduce induced drag which has a significant effect on fuel consumption. A preliminary sizing method which employs an optimization algorithm is utilized. The Airbus A320 aircraft is used as a reference aircraft to evaluate design parameters and to investigate the C-Wing design potential beyond current wing tip designs. An increase in aspect ratio due to wing area reduction at 36m span results in a reduction of required fuel mass by 16%. Also take-off mass savings were obtained for the aircraft with C-Wing configuration. The effect of a variations of height to span ratio (h/b of C-Wings on induced drag factor k, is formulated from a vortex lattice method and literature based equations. Finally the DOC costing methods used by the Association of European Airlines (AEA was applied to the existing A320 aircraft and to the C-Wing configuration obtaining a reduction of 6% in Direct Operating Costs (DOC for the novel concept resulted. From overall outcomes, the C-Wing concept suggests interesting aerodynamic efficiency and stability benefits.

  6. An interactive system for aircraft design and optimization (United States)

    Kroo, Ilan M.


    A system for aircraft design utilizing a unique analysis architecture, graphical interface, and suite of numerical optimization methods is described in this paper. The non-procedural architecture provides extensibility and efficiency not possible with conventional programming techniques. The interface for analysis and optimization, developed for use with this method, is described and its application to example problems is discussed.

  7. Engine Conceptual Design Studies for a Hybrid Wing Body Aircraft (United States)

    Tong, Michael T.; Jones, Scott M.; Haller, William J.; Handschuh, Robert F.


    Worldwide concerns of air quality and climate change have made environmental protection one of the most critical issues in aviation today. NASA s current Fundamental Aeronautics Research program is directed at three generations of aircraft in the near, mid and far term, with initial operating capability around 2015, 2020, and 2030, respectively. Each generation has associated goals for fuel burn, NOx, noise, and field-length reductions relative to today s aircrafts. The research for the 2020 generation is directed at enabling a hybrid wing body (HWB) aircraft to meet NASA s aggressive technology goals. This paper presents the conceptual cycle and mechanical designs of the two engine concepts, podded and embedded systems, which were proposed for a HWB cargo freighter. They are expected to offer significant benefits in noise reductions without compromising the fuel burn.

  8. Research of low boom and low drag supersonic aircraft design

    Institute of Scientific and Technical Information of China (English)

    Feng Xiaoqiang; Li Zhanke; Song Bifeng


    Sonic boom reduction will be an issue of utmost importance in future supersonic trans-port, due to strong regulations on acoustic nuisance. The paper describes a new multi-objective optimization method for supersonic aircraft design. The method is developed by coupling Seebass-George-Darden (SGD) inverse design method and multi-objective genetic algorithm. Based on the method, different codes are developed. Using a computational architecture, a concep-tual supersonic aircraft design environment (CSADE) is constructed. The architecture of CSADE includes inner optimization level and out optimization level. The low boom configuration is gener-ated in inner optimization level by matching the target equivalent area distribution and actual equivalent area distribution. And low boom/low drag configuration is generated in outer optimiza-tion level by using NSGA-II multi-objective genetic algorithm to optimize the control parameters of SGD method and aircraft shape. Two objective functions, low sonic boom and low wave drag, are considered in CSADE. Physically reasonable Pareto solutions are obtained from the present optimization. Some supersonic aircraft configurations are selected from Pareto front and the optimization results indicate that the swept forward wing configuration has benefits in both sonic boom reduction and wave drag reduction. The results are validated by using computational fluid dynamics (CFD) analysis.

  9. Research of low boom and low drag supersonic aircraft design

    Directory of Open Access Journals (Sweden)

    Feng Xiaoqiang


    Full Text Available Sonic boom reduction will be an issue of utmost importance in future supersonic transport, due to strong regulations on acoustic nuisance. The paper describes a new multi-objective optimization method for supersonic aircraft design. The method is developed by coupling Seebass–George–Darden (SGD inverse design method and multi-objective genetic algorithm. Based on the method, different codes are developed. Using a computational architecture, a conceptual supersonic aircraft design environment (CSADE is constructed. The architecture of CSADE includes inner optimization level and out optimization level. The low boom configuration is generated in inner optimization level by matching the target equivalent area distribution and actual equivalent area distribution. And low boom/low drag configuration is generated in outer optimization level by using NSGA-II multi-objective genetic algorithm to optimize the control parameters of SGD method and aircraft shape. Two objective functions, low sonic boom and low wave drag, are considered in CSADE. Physically reasonable Pareto solutions are obtained from the present optimization. Some supersonic aircraft configurations are selected from Pareto front and the optimization results indicate that the swept forward wing configuration has benefits in both sonic boom reduction and wave drag reduction. The results are validated by using computational fluid dynamics (CFD analysis.

  10. Interactive Graphics Analysis for Aircraft Design (United States)

    Townsend, J. C.


    Program uses higher-order far field drag minimization. Computer program WDES WDEM preliminary aerodynamic design tool for one or two interacting, subsonic lifting surfaces. Subcritical wing design code employs higher-order far-field drag minimization technique. Linearized aerodynamic theory used. Program written in FORTRAN IV.

  11. Multidisciplinary Optimization Methods for Aircraft Preliminary Design (United States)

    Kroo, Ilan; Altus, Steve; Braun, Robert; Gage, Peter; Sobieski, Ian


    This paper describes a research program aimed at improved methods for multidisciplinary design and optimization of large-scale aeronautical systems. The research involves new approaches to system decomposition, interdisciplinary communication, and methods of exploiting coarse-grained parallelism for analysis and optimization. A new architecture, that involves a tight coupling between optimization and analysis, is intended to improve efficiency while simplifying the structure of multidisciplinary, computation-intensive design problems involving many analysis disciplines and perhaps hundreds of design variables. Work in two areas is described here: system decomposition using compatibility constraints to simplify the analysis structure and take advantage of coarse-grained parallelism; and collaborative optimization, a decomposition of the optimization process to permit parallel design and to simplify interdisciplinary communication requirements.

  12. Aeroelastic Considerations in the Preliminary Design Aircraft (United States)


    DESIGN OBJECTIVES FEM FASO MODELINGWEGS TRNFRAIS SIZING RIGID AtP .FIRST FIRST FLEX FIRST FLEXSTATICLOADS [ IZING STATIC LOADS SIZING UPDATEFLEX SIZING...Structural Optimization by ASAT A computer software system called ASAT (Automatische Struktur Auslegung von Trag- flchen) exists at MBB which allows

  13. Mathematical analysis of aircraft intercooler design (United States)

    Joyner, Upshur T


    A mathematical analysis has been made to show the method of obtaining the dimensions of the intercooler that will use the least total power for a given set of design conditions. The results of this analysis have been used in a sample calculation and, on the basis of this calculation, a new inter cooler arrangement is suggested. Because the length of the two air passages of the new arrangement is short in comparison with the third dimension, the height of the intercooler, this intercooler arrangement has unusual dimensions. These dimensions give the proposed intercooler arrangement an advantage over one of usual dimensions because less total power will be consumed by the intercooler, the weight and volume of the intercooler will be smaller, and the pressure drop of both the engine air and the cooling air in passing through the intercooler will be lower.

  14. Handling Quality Requirements for Advanced Aircraft Design: Longitudinal Mode (United States)


    regarded by implication or otherwise as in any manner licensing the holder or any other person or corporation, or conveying any rights or permission...analog hardware specifications and seleccion on the DFCS performance. * Consideration of the potential degradation of DFCS performance and research or even for the engineering design of an aircraft or FCS, matters of style and personal taste can dictate how one chooses to

  15. LMI–based robust controller design approach in aircraft multidisciplinary design optimization problem

    Directory of Open Access Journals (Sweden)

    Qinghua Zeng


    Full Text Available This article proposes a linear matrix inequality–based robust controller design approach to implement the synchronous design of aircraft control discipline and other disciplines, in which the variation in design parameters is treated as equivalent perturbations. Considering the complicated mapping relationships between the coefficient arrays of aircraft motion model and the aircraft design parameters, the robust controller designed is directly based on the variation in these coefficient arrays so conservative that the multidisciplinary design optimization problem would be too difficult to solve, or even if there is a solution, the robustness of design result is generally poor. Therefore, this article derives the uncertainty model of disciplinary design parameters based on response surface approximation, converts the design problem of the robust controller into a problem of solving a standard linear matrix inequality, and theoretically gives a less conservative design method of the robust controller which is based on the variation in design parameters. Furthermore, the concurrent subspace approach is applied to the multidisciplinary system with this kind of robust controller in the design loop. A multidisciplinary design optimization of a tailless aircraft as example is shown that control discipline can be synchronous optimal design with other discipline, especially this method will greatly reduce the calculated amount of multidisciplinary design optimization and make multidisciplinary design optimization results more robustness of flight performance.

  16. Advances in aircraft design: Multiobjective optimization and a markup language (United States)

    Deshpande, Shubhangi

    Today's modern aerospace systems exhibit strong interdisciplinary coupling and require a multidisciplinary, collaborative approach. Analysis methods that were once considered feasible only for advanced and detailed design are now available and even practical at the conceptual design stage. This changing philosophy for conducting conceptual design poses additional challenges beyond those encountered in a low fidelity design of aircraft. This thesis takes some steps towards bridging the gaps in existing technologies and advancing the state-of-the-art in aircraft design. The first part of the thesis proposes a new Pareto front approximation method for multiobjective optimization problems. The method employs a hybrid optimization approach using two derivative free direct search techniques, and is intended for solving blackbox simulation based multiobjective optimization problems with possibly nonsmooth functions where the analytical formof the objectives is not known and/or the evaluation of the objective function(s) is very expensive (very common in multidisciplinary design optimization). A new adaptive weighting scheme is proposed to convert a multiobjective optimization problem to a single objective optimization problem. Results show that the method achieves an arbitrarily close approximation to the Pareto front with a good collection of well-distributed nondominated points. The second part deals with the interdisciplinary data communication issues involved in a collaborative mutidisciplinary aircraft design environment. Efficient transfer, sharing, and manipulation of design and analysis data in a collaborative environment demands a formal structured representation of data. XML, a W3C recommendation, is one such standard concomitant with a number of powerful capabilities that alleviate interoperability issues. A compact, generic, and comprehensive XML schema for an aircraft design markup language (ADML) is proposed here to provide a common language for data

  17. Conceptual design proposal: HUGO global range/mobility transport aircraft (United States)

    Johnston, Tom; Perretta, Dave; Mcbane, Doug; Morin, Greg; Thomas, Greg; Woodward, Joe; Gulakowski, Steve


    With the collapse of the former Soviet Union and the emergence of the United Nations actively pursuing a peace keeping role in world affairs, the United States has been forced into a position as the world's leading peace enforcer. It is still a very dangerous world with seemingly never ending ideological, territorial, and economic disputes requiring the U.S. to maintain a credible deterrent posture in this uncertain environment. This has created an urgent need to rapidly transport large numbers of troops and equipment from the continental United States (CONUS) to any potential world trouble spot by means of a global range/mobility transport aircraft. The most recent examples being Operation Desert Shield/Storm and Operation Restore Hope. To meet this challenge head-on, a request for proposal (RFP) was developed and incorporated into the 1992/1993 AIAA/McDonnell Douglas Corporation Graduate Team Aircraft Design Competition. The RFP calls for the conceptual design and justification of a large aircraft capable of power projecting a significant military force without surface transportation reliance.

  18. N+3 Aircraft Concept Designs and Trade Studies. Volume 1 (United States)

    Greitzer, E. M.; Bonnefoy, P. A.; DelaRosaBlanco, E.; Dorbian, C. S.; Drela, M.; Hall, D. K.; Hansman, R. J.; Hileman, J. I.; Liebeck, R. H.; Levegren, J.; Mody, P.; Pertuze, J. A.; Sato, S.; Spakovszky, Z. S.; Tan, C. S.; Hollman, J. S.; Duda, J. E.; Fitzgerald, N.; Houghton, J.; Kerrebrock, J. L.; Kiwada, G. F.; Kordonowy, D.; Parrish, J. C.; Tylko, J.; Wen, E. A.


    MIT, Aerodyne Research, Aurora Flight Sciences, and Pratt & Whitney have collaborated to address NASA s desire to pursue revolutionary conceptual designs for a subsonic commercial transport that could enter service in the 2035 timeframe. The MIT team brings together multidisciplinary expertise and cutting-edge technologies to determine, in a rigorous and objective manner, the potential for improvements in noise, emissions, and performance for subsonic fixed wing transport aircraft. The collaboration incorporates assessment of the trade space in aerodynamics, propulsion, operations, and structures to ensure that the full spectrum of improvements is identified. Although the analysis focuses on these key areas, the team has taken a system-level approach to find the integrated solutions that offer the best balance in performance enhancements. Based on the trade space analyses and system-level assessment, two aircraft have been identified and carried through conceptual design to show both the in-depth engineering that underpins the benefits envisioned and also the technology paths that need to be followed to enable, within the next 25 years, the development of aircraft three generations ahead in capabilities from those flying today.

  19. System Synthesis in Preliminary Aircraft Design Using Statistical Methods (United States)

    DeLaurentis, Daniel; Mavris, Dimitri N.; Schrage, Daniel P.


    This paper documents an approach to conceptual and early preliminary aircraft design in which system synthesis is achieved using statistical methods, specifically Design of Experiments (DOE) and Response Surface Methodology (RSM). These methods are employed in order to more efficiently search the design space for optimum configurations. In particular, a methodology incorporating three uses of these techniques is presented. First, response surface equations are formed which represent aerodynamic analyses, in the form of regression polynomials, which are more sophisticated than generally available in early design stages. Next, a regression equation for an Overall Evaluation Criterion is constructed for the purpose of constrained optimization at the system level. This optimization, though achieved in an innovative way, is still traditional in that it is a point design solution. The methodology put forward here remedies this by introducing uncertainty into the problem, resulting in solutions which are probabilistic in nature. DOE/RSM is used for the third time in this setting. The process is demonstrated through a detailed aero-propulsion optimization of a High Speed Civil Transport. Fundamental goals of the methodology, then, are to introduce higher fidelity disciplinary analyses to the conceptual aircraft synthesis and provide a roadmap for transitioning from point solutions to probabilistic designs (and eventually robust ones).

  20. Sonic Boom Mitigation Through Aircraft Design and Adjoint Methodology (United States)

    Rallabhandi, Siriam K.; Diskin, Boris; Nielsen, Eric J.


    This paper presents a novel approach to design of the supersonic aircraft outer mold line (OML) by optimizing the A-weighted loudness of sonic boom signature predicted on the ground. The optimization process uses the sensitivity information obtained by coupling the discrete adjoint formulations for the augmented Burgers Equation and Computational Fluid Dynamics (CFD) equations. This coupled formulation links the loudness of the ground boom signature to the aircraft geometry thus allowing efficient shape optimization for the purpose of minimizing the impact of loudness. The accuracy of the adjoint-based sensitivities is verified against sensitivities obtained using an independent complex-variable approach. The adjoint based optimization methodology is applied to a configuration previously optimized using alternative state of the art optimization methods and produces additional loudness reduction. The results of the optimizations are reported and discussed.

  1. Conceptual design of hybrid-electric transport aircraft (United States)

    Pornet, C.; Isikveren, A. T.


    The European Flightpath 2050 and corresponding Strategic Research and Innovation Agenda (SRIA) as well as the NASA Environmentally Responsible Aviation N+ series have elaborated aggressive emissions and external noise reduction targets according to chronological waypoints. In order to deliver ultra-low or even zero in-flight emissions levels, there exists an increasing amount of international research and development emphasis on electrification of the propulsion and power systems of aircraft. Since the late 1990s, a series of experimental and a host of burgeouning commercial activities for fixed-wing aviation have focused on glider, ultra-light and light-sport airplane, and this is proving to serve as a cornerstone for more ambitious transport aircraft design and integration technical approaches. The introduction of hybrid-electric technology has dramatically expanded the design space and the full-potential of these technologies will be drawn through synergetic, tightly-coupled morphological and systems integration emphasizing propulsion - as exemplified by the potential afforded by distributed propulsion solutions. With the aim of expanding upon the current repository of knowledge associated with hybrid-electric propulsion systems a quad-fan arranged narrow-body transport aircraft equipped with two advanced Geared-Turbofans (GTF) and two Electrical Fans (EF) in an under-wing podded installation is presented in this technical article. The assessment and implications of an increasing Degree-of-Hybridization for Useful Power (HP,USE) on the overall sizing, performance as well as flight technique optimization of fuel-battery hybrid-electric aircraft is addressed herein. The integrated performance of the concept was analyzed in terms of potential block fuel burn reduction and change in vehicular efficiency in comparison to a suitably projected conventional aircraft employing GTF-only propulsion targeting year 2035. Results showed that by increasing HP,USE, significant

  2. Aircraft (United States)

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


    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.

  3. An Indispensable Ingredient: Flight Research and Aircraft Design (United States)

    Gorn, Michael H.


    Flight research-the art of flying actual vehicles in the atmosphere in order to collect data about their behavior-has played a historic and decisive role in the design of aircraft. Naturally, wind tunnel experiments, computational fluid dynamics, and mathematical analyses all informed the judgments of the individuals who conceived of new aircraft. But flight research has offered moments of realization found in no other method. Engineer Dale Reed and research pilot Milt Thompson experienced one such epiphany on March 1, 1963, at the National Aeronautics and Space Administration s Dryden Flight Research Center in Edwards, California. On that date, Thompson sat in the cockpit of a small, simple, gumdrop-shaped aircraft known as the M2-F1, lashed by a long towline to a late-model Pontiac Catalina. As the Pontiac raced across Rogers Dry Lake, it eventually gained enough speed to make the M2-F1 airborne. Thompson braced himself for the world s first flight in a vehicle of its kind, called a lifting body because of its high lift-to-drag ratio. Reed later recounted what he saw:

  4. An Advanced Open-Source Aircraft Design Platform for Personal Air Vehicle Geometry, Aerodynamics, and Structures Project (United States)

    National Aeronautics and Space Administration — Innovators working to revolutionize air travel through personal aviation pioneers need innovative aircraft design tools. Vehicle Sketch Pad (VSP) is an aircraft...

  5. Design Qualification of an External Store for a Fighter Aircraft

    Directory of Open Access Journals (Sweden)

    V.B. Goley


    Full Text Available Defence Avionics Research Establishment (DARE has designed and developed an externalstore for fitment on a fighter aircraft. The external store has the poded structure and can be usedfor installation of a variety of payloads up to 250 kg. The mechanical details of the electronicsto be fitted inside the pod can be worked out as per application. The pod has been designedkeeping this in mind and based on the functional, mechanical, structural, and aerodynamicrequirements. The designed and fabricated pod has undergone various qualification tests. Thepaper brings out the details of the pod design, and the various structural and environmentalqualification tests carried out. The pod thus designed and qualified has been validated throughcarriage trials by fitting the pod on the platform intended for it. The pod is likely to be inductedinto the Services shortly.

  6. Integrating Cloud-Computing-Specific Model into Aircraft Design (United States)

    Zhimin, Tian; Qi, Lin; Guangwen, Yang

    Cloud Computing is becoming increasingly relevant, as it will enable companies involved in spreading this technology to open the door to Web 3.0. In the paper, the new categories of services introduced will slowly replace many types of computational resources currently used. In this perspective, grid computing, the basic element for the large scale supply of cloud services, will play a fundamental role in defining how those services will be provided. The paper tries to integrate cloud computing specific model into aircraft design. This work has acquired good results in sharing licenses of large scale and expensive software, such as CFD (Computational Fluid Dynamics), UG, CATIA, and so on.

  7. Flow simulation and shape optimization for aircraft design (United States)

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


    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.

  8. An integrated approach to the design of an aircraft gain scheduled controller


    Berglund, Erik


    This thesis addresses the problem of integrated design of the aircraft plant parameters and of the corresponding feedback controller. The plant parameters are typically the sizes of the control surfaces or other aerodynamical surfaces of the aircraft. The approach is to rewrite the aircraft dynamic requirements as linear matrix inequalities (LMI's) and to optimize a linear cost function associated with aircraft plant parameters, while meeting the LMI constraints. An algorithm using Matlab and...

  9. An integrated systems engineering approach to aircraft design (United States)

    Price, M.; Raghunathan, S.; Curran, R.


    The challenge in Aerospace Engineering, in the next two decades as set by Vision 2020, is to meet the targets of reduction of nitric oxide emission by 80%, carbon monoxide and carbon dioxide both by 50%, reduce noise by 50% and of course with reduced cost and improved safety. All this must be achieved with expected increase in capacity and demand. Such a challenge has to be in a background where the understanding of physics of flight has changed very little over the years and where industrial growth is driven primarily by cost rather than new technology. The way forward to meet the challenges is to introduce innovative technologies and develop an integrated, effective and efficient process for the life cycle design of aircraft, known as systems engineering (SE). SE is a holistic approach to a product that comprises several components. Customer specifications, conceptual design, risk analysis, functional analysis and architecture, physical architecture, design analysis and synthesis, and trade studies and optimisation, manufacturing, testing validation and verification, delivery, life cycle cost and management. Further, it involves interaction between traditional disciplines such as Aerodynamics, Structures and Flight Mechanics with people- and process-oriented disciplines such as Management, Manufacturing, and Technology Transfer. SE has become the state-of-the-art methodology for organising and managing aerospace production. However, like many well founded methodologies, it is more difficult to embody the core principles into formalised models and tools. The key contribution of the paper will be to review this formalisation and to present the very latest knowledge and technology that facilitates SE theory. Typically, research into SE provides a deeper understanding of the core principles and interactions, and helps one to appreciate the required technical architecture for fully exploiting it as a process, rather than a series of events. There are major issues as

  10. PIFCGT: A PIF autopilot design program for general aviation aircraft (United States)

    Broussard, J. R.


    This report documents the PIFCGT computer program. In FORTRAN, PIFCGT is a computer design aid for determing Proportional-Integral-Filter (PIF) control laws for aircraft autopilots implemented with a Command Generator Tracker (CGT). The program uses Linear-Quadratic-Regulator synthesis algorithms to determine feedback gains, and includes software to solve the feedforward matrix equation which is useful in determining the command generator tracker feedforward gains. The program accepts aerodynamic stability derivatives and computes the corresponding aerodynamic linear model. The nine autopilot modes that can be designed include four maneuver modes (ROLL SEL, PITCH SEL, HDG SEL, ALT SEL), four final approach models (APR GS, APR LOCI, APR LOCR, APR LOCP), and a BETA HOLD mode. The program has been compiled and executed on a CDC computer.

  11. Conceptual design for a laminar-flying-wing aircraft (United States)

    Saeed, T. I.

    The laminar-flying-wing aircraft appears to be an attractive long-term prospect for reducing the environmental impact of commercial aviation. In assessing its potential, a relatively straightforward initial step is the conceptual design of a version with restricted sweep angle. Such a design is the topic of this thesis. Subject to constraints, this research aims to; provide insight into the parameters affecting practical laminar-flow-control suction power requirements; identify a viable basic design specification; and, on the basis of this, an assessment of the fuel efficiency through a detailed conceptual design study. It is shown that there is a minimum power requirement independent of the suction system design, associated with the stagnation pressure loss in the boundary layer. This requirement increases with aerofoil section thickness, but depends only weakly on Mach number and (for a thick, lightly-loaded laminar flying wing) lift coefficient. Deviation from the optimal suction distribution, due to a practical chamber-based architecture, is found to have very little effect on the overall suction coefficient. In the spanwise direction, through suitable choice of chamber depth, the pressure drop due to frictional and inertial effects may be rendered negligible. Finally, it is found that the pressure drop from the aerofoil surface to the pump collector ducts determines the power penalty. To identify the viable basic design specification, a high-level exploration of the laminar flying wing design space is performed. The characteristics of the design are assessed as a function of three parameters: thickness-to-chord ratio, wingspan, and unit Reynolds number. A feasible specification, with 20% thickness-to-chord, 80 m span and a unit Reynolds number of 8 x 106 m-1, is identified; it corresponds to a 187 tonne aircraft which cruises at Mach 0.67 and altitude 22,500 ft, with lift coefficient 0.14. On the basis of this specification, a detailed conceptual design is

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

    Directory of Open Access Journals (Sweden)

    Tian Yifeng


    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.

  13. A Novel Design of Aircraft Fuel Tank Inspection Robot

    Directory of Open Access Journals (Sweden)

    Guochen Niu


    Full Text Available Aircraft fuel tank leakage is a very common maintenance problem. A continuum robot is designed for troubleshooting of leaks for fuel tank which has strong constraints and is also explosive. The biomimetic robot with several flexible sections applies actuation redundancy through pulling its four independent driving cables to realize bending motion of two degrees of freedom (DOF. The forward kinematics about the relations of cables lengths, angles and tip coordinates of single section is established using projection curvature method and coordinates transformation method. The decoupled multi-section kinematics function is deduced based on the kinematics analysis of single section. Simulations of single section motion are presented. We demonstrate finally the correctness of kinematics method through prototype experiments.  

  14. Design of a digital ride quality augmentation system for commuter aircraft (United States)

    Hammond, T. A.; Amin, S. P.; Paduano, J. D.; Downing, D. R.


    Commuter aircraft typically have low wing loadings, and fly at low altitudes, and so they are susceptible to undesirable accelerations caused by random atmospheric turbulence. Larger commercial aircraft typically have higher wing loadings and fly at altitudes where the turbulence level is lower, and so they provide smoother rides. This project was initiated based on the goal of making the ride of the commuter aircraft as smooth as the ride experienced on the major commercial airliners. The objectives of this project were to design a digital, longitudinal mode ride quality augmentation system (RQAS) for a commuter aircraft, and to investigate the effect of selected parameters on those designs.

  15. Flying Qualities Metrics and Design Guidelines for Modern Transport Aircraft Project (United States)

    National Aeronautics and Space Administration — Current and planned transport aircraft designs are making more use of fly-by-wire technology, allowing an unprecedented design space for control laws, including...

  16. Challenge to Aviation: Hatching a Leaner Pterosauer. [Improving Commercial Aircraft Design for Greater Fuel Efficiency (United States)

    Moss, F. E.


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

  17. Meeting the challenges with the Douglas Aircraft Company Aeroelastic Design Optimization Program (ADOP) (United States)

    Rommel, Bruce A.


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

  18. Improving the Aircraft Design Process Using Web-Based Modeling and Simulation (United States)

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


    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.

  19. A trade-off analysis design tool. Aircraft interior noise-motion/passenger satisfaction model (United States)

    Jacobson, I. D.


    A design tool was developed to enhance aircraft passenger satisfaction. The effect of aircraft interior motion and noise on passenger comfort and satisfaction was modelled. Effects of individual aircraft noise sources were accounted for, and the impact of noise on passenger activities and noise levels to safeguard passenger hearing were investigated. The motion noise effect models provide a means for tradeoff analyses between noise and motion variables, and also provide a framework for optimizing noise reduction among noise sources. Data for the models were collected onboard commercial aircraft flights and specially scheduled tests.

  20. Detailed design of a Ride Quality Augmentation System for commuter aircraft (United States)

    Suikat, Reiner; Donaldson, Kent E.; Downing, David R.


    The design of a Ride Quality Augmentation System (RQAS) for commuter aircraft is documented. The RQAS is designed for a Cessna 402B, an 8 passenger prop twin representative to this class of aircraft. The purpose of the RQAS is the reduction of vertical and lateral accelerations of the aircraft due to atmospheric turbulence by the application of active control. The detailed design of the hardware (the aircraft modifications, the Ride Quality Instrumentation System (RQIS), and the required computer software) is examined. The aircraft modifications, consisting of the dedicated control surfaces and the hydraulic actuation system, were designed at Cessna Aircraft by Kansas University-Flight Research Laboratory. The instrumentation system, which consist of the sensor package, the flight computer, a Data Acquisition System, and the pilot and test engineer control panels, was designed by NASA-Langley. The overall system design and the design of the software, both for flight control algorithms and ground system checkout are detailed. The system performance is predicted from linear simulation results and from power spectral densities of the aircraft response to a Dryden gust. The results indicate that both accelerations are possible.

  1. An Integrated Approach to Aircraft Modelling and Flight Control Law Design

    NARCIS (Netherlands)

    Looye, G.H.N.


    The design of flight control laws (FCLs) for automatic and manual (augmented) control of aircraft is a complicated task. FCLs have to fulfil large amounts of performance criteria and must work reliably in all flight conditions, for all aircraft configurations, and in adverse weather conditions. Cons

  2. Lightweight diesel engine designs for commuter type aircraft (United States)

    Brouwers, A. P.


    Conceptual designs and performance of advanced technology lightweight diesel engines, suitable for commuter type aircraft power plants are defined. Two engines are discussed, a 1491 kW (2000 SHP) eight-cylinder engine and a 895 kW (1200 SHP) six-cylinder engine. High performance and related advanced technologies are proposed such as insulated cylinders, very high injection pressures and high compressor and turbine efficiencies. The description of each engine includes concept drawings, a performance analysis, and weight data. Fuel flow data are given for full and partial power up to 7620m altitude. The performance data are also extrapolated over a power range from 671 kW(900SHP) to 1864 kW (2500 SHP). The specific fuel consumption of the 1491 kW (2000 SHP) engine is 182 g/hWh (.299 lb/HPh) at cruise altitude, its weight 620 kg (1365 lb.) and specific weight .415 kg/kW (.683 lb/HP). The specific fuel consumption of the 895 kW (1200 SHP) engine is 187 g/hWh (.308 lb/HPh) at cruise altitude, its weight 465 kg (1025 lb.) and specific weight .520 kg/kW (.854 lb/HP).

  3. The effects of aircraft design on STOL ride quality (United States)

    Jones, C. R.; Jacobson, I. D.


    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.

  4. A computer module used to calculate the horizontal control surface size of a conceptual aircraft design (United States)

    Sandlin, Doral R.; Swanson, Stephen Mark


    The creation of a computer module used to calculate the size of the horizontal control surfaces of a conceptual aircraft design is discussed. The control surface size is determined by first calculating the size needed to rotate the aircraft during takeoff, and, second, by determining if the calculated size is large enough to maintain stability of the aircraft throughout any specified mission. The tail size needed to rotate during takeoff is calculated from a summation of forces about the main landing gear of the aircraft. The stability of the aircraft is determined from a summation of forces about the center of gravity during different phases of the aircraft's flight. Included in the horizontal control surface analysis are: downwash effects on an aft tail, upwash effects on a forward canard, and effects due to flight in close proximity to the ground. Comparisons of production aircraft with numerical models show good accuracy for control surface sizing. A modified canard design verified the accuracy of the module for canard configurations. Added to this stability and control module is a subroutine that determines one of the three design variables, for a stable vectored thrust aircraft. These include forward thrust nozzle position, aft thrust nozzle angle, and forward thrust split.

  5. A knowledge-based system design/information tool for aircraft flight control systems (United States)

    Mackall, Dale A.; Allen, James G.


    Research aircraft have become increasingly dependent on advanced electronic control systems to accomplish program goals. These aircraft are integrating multiple disciplines to improve performance and satisfy research objective. This integration is being accomplished through electronic control systems. Systems design methods and information management have become essential to program success. The primary objective of the system design/information tool for aircraft flight control is to help transfer flight control system design knowledge to the flight test community. By providing all of the design information and covering multiple disciplines in a structured, graphical manner, flight control systems can more easily be understood by the test engineers. This will provide the engineers with the information needed to thoroughly ground test the system and thereby reduce the likelihood of serious design errors surfacing in flight. The secondary object is to apply structured design techniques to all of the design domains. By using the techniques in the top level system design down through the detailed hardware and software designs, it is hoped that fewer design anomalies will result. The flight test experiences are reviewed of three highly complex, integrated aircraft programs: the X-29 forward swept wing; the advanced fighter technology integration (AFTI) F-16; and the highly maneuverable aircraft technology (HiMAT) program. Significant operating technologies, and the design errors which cause them, is examined to help identify what functions a system design/informatin tool should provide to assist designers in avoiding errors.

  6. Multidisciplinary design and optimization (MDO) methodology for the aircraft conceptual design (United States)

    Iqbal, Liaquat Ullah

    An integrated design and optimization methodology has been developed for the conceptual design of an aircraft. The methodology brings higher fidelity Computer Aided Design, Engineering and Manufacturing (CAD, CAE and CAM) Tools such as CATIA, FLUENT, ANSYS and SURFCAM into the conceptual design by utilizing Excel as the integrator and controller. The approach is demonstrated to integrate with many of the existing low to medium fidelity codes such as the aerodynamic panel code called CMARC and sizing and constraint analysis codes, thus providing the multi-fidelity capabilities to the aircraft designer. The higher fidelity design information from the CAD and CAE tools for the geometry, aerodynamics, structural and environmental performance is provided for the application of the structured design methods such as the Quality Function Deployment (QFD) and the Pugh's Method. The higher fidelity tools bring the quantitative aspects of a design such as precise measurements of weight, volume, surface areas, center of gravity (CG) location, lift over drag ratio, and structural weight, as well as the qualitative aspects such as external geometry definition, internal layout, and coloring scheme early in the design process. The performance and safety risks involved with the new technologies can be reduced by modeling and assessing their impact more accurately on the performance of the aircraft. The methodology also enables the design and evaluation of the novel concepts such as the blended (BWB) and the hybrid wing body (HWB) concepts. Higher fidelity computational fluid dynamics (CFD) and finite element analysis (FEA) allow verification of the claims for the performance gains in aerodynamics and ascertain risks of structural failure due to different pressure distribution in the fuselage as compared with the tube and wing design. The higher fidelity aerodynamics and structural models can lead to better cost estimates that help reduce the financial risks as well. This helps in

  7. Seat Capacity Selection for an Advanced Short-Haul Aircraft Design (United States)

    Marien, Ty V.


    A study was performed to determine the target seat capacity for a proposed advanced short-haul aircraft concept projected to enter the fleet by 2030. This analysis projected the potential demand in the U.S. for a short-haul aircraft using a transportation theory approach, rather than selecting a target seat capacity based on recent industry trends or current market demand. A transportation systems model was used to create a point-to-point network of short-haul trips and then predict the number of annual origin-destination trips on this network. Aircraft of varying seat capacities were used to meet the demand on this network, assuming a single aircraft type for the entire short-haul fleet. For each aircraft size, the ticket revenue and operational costs were used to calculate a total market profitability metric for all feasible flights. The different aircraft sizes were compared, based on this market profitability metric and also the total number of annual round trips and markets served. Sensitivity studies were also performed to determine the effect of changing the aircraft cruise speed and maximum trip length. Using this analysis, the advanced short-haul aircraft design team was able to select a target seat capacity for their design.

  8. Integration of noise control into the product design process : a case study : the Silent Aircraft Initiative

    Energy Technology Data Exchange (ETDEWEB)

    Faszer, A. [Noise Solutions Inc., Calgary, AB (Canada)


    The Silent Aircraft Initiative (SAI) is a study being conducted by the Cambridge-MIT Institute to discover ways to significantly reduce aircraft noise. Part of the study focuses on developing aircraft and engine designs that meet the SAI objectives. This presentation included several illustrations of the favoured configuration of a blended wing design, with 4 engines located on the upper surface of a shallow wing which shields engine noise. This presentation described various engine parts such as the low specific thrust turbofan, the variable area nozzle and the acoustic treatment in the intake and exhaust turbomachinery that minimizes noise. The requirements for market viability of the aircraft were discussed as well as the technical challenges in terms of its propulsion systems; structural analysis; mechanical design; low speed aerodynamic performance; cabin layout; and maintenance considerations. It was concluded that the SAI has achieved a credible conceptual aircraft design given the high risk of the technologies used. The project has met objectives of a functionally silent and fuel efficient aircraft. The new conceptual aircraft has potential for fuel burn of 149 pax-miles per imperial gallon and noise of 63 dBA near the perimeter of airports. 1 tab., 48 figs.

  9. Conceptual design and RCS performance research of shipborne early warning aircraft

    Institute of Scientific and Technical Information of China (English)

    Kuizhi Yue; Yong Gao; Guanxiong Li; Dazhao Yu


    In order to improve the survivability of the aircraft, conceptual design and radar cross section (RCS) performance research are done. The CATIA software is used to design the 3D digital model of the shipborne early warning aircraft, and some measures are taken to reduce the RCS characteristics of the early warning aircraft at the same time. Based on the physical optics method and the equivalent electromagnetic flow method, the aircraft’s RCS characteristics and strength distribution charac-teristics are simulated numerical y, and compared with the foreign advanced shipborne early warning aircraft. The simulation results show that under the X radar band, when the incident wave pitching angle is 0◦, compared with the foreign advanced shipborne early warning aircraft, the forward RCS average value of the concep-tual shipborne early warning aircraft is reduced to 24.49%, the lateral RCS average value is reduced to 5.04%, and the backward RCS average value is reduced to 39.26%. The research results of this paper are expected to provide theoretical basis and technical support for the conceptual design and the stealth design of the shipborne early warning aircraft.

  10. Numeric Design and Performance Analysis of Solid Oxide Fuel Cell -- Gas Turbine Hybrids on Aircraft (United States)

    Hovakimyan, Gevorg

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

  11. Design of adaptive switching control for hypersonic aircraft

    Directory of Open Access Journals (Sweden)

    Xin Jiao


    Full Text Available This article proposes a novel adaptive switching control of hypersonic aircraft based on type-2 Takagi–Sugeno–Kang fuzzy sliding mode control and focuses on the problem of stability and smoothness in the switching process. This method uses full-state feedback to linearize the nonlinear model of hypersonic aircraft. Combining the interval type-2 Takagi–Sugeno–Kang fuzzy approach with sliding mode control keeps the adaptive switching process stable and smooth. For rapid stabilization of the system, the adaptive laws use a direct constructive Lyapunov analysis together with an established type-2 Takagi–Sugeno–Kang fuzzy logic system. Simulation results indicate that the proposed control scheme can maintain the stability and smoothness of switching process for the hypersonic aircraft.

  12. On Physical Aeroacoustics with Some Implications for Low-Noise Aircraft Design and Airport Operations

    Directory of Open Access Journals (Sweden)

    Luís M. B. C. Campos


    Full Text Available Air traffic is growing at a steady rate of 3% to 5% per year in most regions of the world, implying a doubling every 15–25 years. This requires major advances in aircraft noise reduction at airports, just not to increase the noise exposure due to the larger number of aircraft movements. In fact it can be expected, as a consequence of increased opposition to noise by near airport residents, that the overall noise exposure will have to be reduced, by bans, curfews, fines, and other means and limitations, unless significantly quieter aircraft operations are achieved. The ultimate solution is aircraft operations inaudible outside the airport perimeter, or noise levels below road traffic and other existing local noise sources. These substantial noise reductions cannot come at the expense of a degradation of cruise efficiency, that would affect not just economics and travel time, but would increase fuel consumption and emission of pollutants on a global scale. The paper reviews the: (i current knowledge of the aircraft noise sources; (ii the sound propagation in the atmosphere and ground effects that determine the noise annoyance of near-airport residents; (iii the noise mitigation measures that can be applied to current and future aircraft; (iv the prospects of evolutionary and novel aircraft designs towards quieter aircraft in the near term and eventually to operations inaudible outside the airport perimeter. The 20 figures and 1 diagram with their legends provide a visual summary of the review.

  13. Aeroelastic Loads Modeling for Composite Aircraft Design Support

    NARCIS (Netherlands)

    Baluch, H.A.


    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

  14. The design and testing of subscale smart aircraft wing bolts (United States)

    Vugampore, J. M. V.; Bemont, C.


    Presently costly periodic inspection is vital in guaranteeing the structural integrity of aircraft. This investigation assesses the potential for significantly reducing aircraft maintenance costs without modification of aircraft structures by implementing smart wing bolts, manufactured from TRIP steel, which can be monitored for damage in situ. TRIP steels undergo a transformation from paramagnetic austenite to ferromagnetic martensite during deformation. Subscale smart aircraft wing bolts were manufactured from hot rolled TRIP steel. These wing bolts were used to demonstrate that washers incorporating embedded inductance coils can be utilized to measure the martensitic transformation occurring in the TRIP steel during bolt deformation. Early in situ warning of a critical bolt stress level was thereby facilitated, potentially reducing the costly requirement for periodic wing bolt removal and inspection. The hot rolled TRIP steels that were utilized in these subscale bolts do not however exhibit the mechanical properties required of wing bolt material. Thus warm rolled TRIP steel alloys were also investigated. The mechanical properties of the best warm rolled TRIP steel alloy tested almost matched those of AISI 4340. The warm rolled alloys were also shown to exhibit transformation before yield, allowing for earlier warning when overload occurs. Further work will be required relating to fatigue crack detection, environmental temperature fluctuation and more thorough material characterization. However, present results show that in situ early detection of wing bolt overload is feasible via the use of high alloy warm rolled TRIP steel wing bolts in combination with inductive sensor embedded washers.

  15. Designing aircraft in Italy; internship at Piaggio Aero Industries


    Coosemans, J.


    From October 2012 to January 2013, I went to the south of Italy to do my internship at Piaggio, the company famous for manufacturing the P.180 Avanti business aircraft. The office where I was located was in Pozzuoli, a town just outside the city of Naples, in the shadow of Mount Vesuvius.

  16. Synthesis from Design Requirements of a Hybrid System for Transport Aircraft Longitudinal Control. Volume 2 (United States)

    Hynes, Charles S.; Hardy, Gordon H.; Sherry, Lance


    Volume I of this report presents a new method for synthesizing hybrid systems directly from desi gn requirements, and applies the method to design of a hybrid system for longitudinal control of transport aircraft. The resulting system satisfies general requirement for safety and effectiveness specified a priori, enabling formal validation to be achieved. Volume II contains seven appendices intended to make the report accessible to readers with backgrounds in human factors, flight dynamics and control, and formal logic. Major design goals are (1) system design integrity based on proof of correctness at the design level, (2) significant simplification and cost reduction in system development and certification, and (3) improved operational efficiency, with significant alleviation of human-factors problems encountered by pilots in current transport aircraft. This report provides for the first time a firm technical basis for criteria governing design and certification of avionic systems for transport aircraft. It should be of primary interest to designers of next-generation avionic systems.

  17. Optimal Input Design for Aircraft Parameter Estimation using Dynamic Programming Principles (United States)

    Morelli, Eugene A.; Klein, Vladislav


    A new technique was developed for designing optimal flight test inputs for aircraft parameter estimation experiments. The principles of dynamic programming were used for the design in the time domain. This approach made it possible to include realistic practical constraints on the input and output variables. A description of the new approach is presented, followed by an example for a multiple input linear model describing the lateral dynamics of a fighter aircraft. The optimal input designs produced by the new technique demonstrated improved quality and expanded capability relative to the conventional multiple input design method.

  18. Design of a digital ride quality augmentation system for a commuter aircraft (United States)

    Hammond, T. A.; Downing, D. R.; Amin, S. P.; Paduano, J.


    Commuter aircraft with low wing loading that operate at low altitudes are particularly susceptible to unwanted accelerations caused by atmospheric gusts. This paper describes the design and analysis of a longitudinal digital Ride Quality Augmentation System (RQAS). The RQAS designs were conducted for a Cessna 402B aircraft using the flaps and the elevator as the control surfaces. The designs are generated using linear quadratic Gaussian theory and analyzed in both the time and frequency domains. Nominal designs are presented at five flight conditions that cover a total mission. Trade-off studies are conducted to investigate the effect of sample time, computational delay time, servo bandwidth and control power.

  19. Aerodynamic aircraft design methods and their notable applications: Survey of the activity in Japan (United States)

    Fujii, Kozo; Takanashi, Susumu


    An overview of aerodynamic aircraft design methods and their recent applications in Japan is presented. A design code which was developed at the National Aerospace Laboratory (NAL) and is in use now is discussed, hence, most of the examples are the result of the collaborative work between heavy industry and the National Aerospace Laboratory. A wide variety of applications in transonic to supersonic flow regimes are presented. Although design of aircraft elements for external flows are the main focus, some of the internal flow applications are also presented. Recent applications of the design code, using the Navier Stokes and Euler equations in the analysis mode, include the design of HOPE (a space vehicle) and Upper Surface Blowing (USB) aircraft configurations.

  20. A Knowledge Based Approach for Automated Modelling of Extended Wing Structures in Preliminary Aircraft Design


    Dorbath, Felix; Nagel, Björn; Gollnick, Volker


    This paper introduces the concept of the ELWIS model generator for Finite Element models of aircraft wing structures. The physical modelling of the structure is extended beyond the wing primary structures, to increase the level of accuracy for aircraft which diverge from existing configurations. Also the impact of novel high lift technologies on structural masses can be captured already in the early stages of design by using the ELWIS models. The ELWIS model generator is able to c...

  1. Toward Reduced Aircraft Community Noise Impact Via a Perception-Influenced Design Approach (United States)

    Rizzi, Stephen A.


    This is an exciting time for aircraft design. New configurations, including small multi-rotor uncrewed aerial systems, fixed- and tilt-wing distributed electric propulsion aircraft, high-speed rotorcraft, hybrid-electric commercial transports, and low-boom supersonic transports, are being made possible through a host of propulsion and airframe technology developments. The resulting noise signatures may be radically different, both spectrally and temporally, than those of the current fleet. Noise certification metrics currently used in aircraft design do not necessarily reflect these characteristics and therefore may not correlate well with human response. Further, as operations and missions become less airport-centric, e.g., those associated with on-demand mobility or package delivery, vehicles may operate in closer proximity to the population than ever before. Fortunately, a new set of tools are available for assessing human perception during the design process in order to affect the final design in a positive manner. The tool chain utilizes system noise prediction methods coupled with auralization and psychoacoustic testing, making possible the inclusion of human response to noise, along with performance criteria and certification requirements, into the aircraft design process. Several case studies are considered to illustrate how this approach could be used to influence the design of future aircraft.

  2. Longitudinal control laws design for a flying wing aircraft


    Zhu, Yan


    This research is concerned with the flight dynamic, pitch flight control and flying qualities assessment for the reference BWB aircraft. It aims to develop the longitudinal control laws which could satisfy the flying and handing qualities over the whole flight envelope with added consideration of centre of gravity (CG) variation. In order to achieve this goal, both the longitudinal stability augmentation system (SAS) and autopilot control laws are studied in this thesis. Usi...

  3. Application of Powered High Lift Systems to STOL Aircraft Design. (United States)


    performance of the S-3A VIKING aircraft was performed. 00 1403 smvw or I Nov ba to NDE ~uv (page 1) 9/34T ases-ea orf iI pil WinR? I=10C I.7 * - -ONE t...D. E. Wilcox and J. A. Cochrane, Tune 1979. 4-4 "QSRA Delivered to Research Center", Aviation Week & Space Technology, Vol. 109, No. 7, p. 20, 14

  4. Aerodynamic study, design and construction of a Blended Wing Body (BWB) Unmanned Aircraft (UA)


    De Toro Diaz, Aleix


    During this project a Blended Wing Body (BWB) UA (Unmanned Aircraft) model is built. BWBs are a combination of a common airplane with tail control surfaces and a flying wing. BWBs lack tail control surfaces, which makes its design to be very different and more complex regarding stability. To first start the BWB design, some research has been done about the basic parameters of the BWB designs. Moreover, different airfoils are considered to improve the stability of the UA. Two designs are creat...

  5. Data management in an object-oriented distributed aircraft conceptual design environment (United States)

    Lu, Zhijie

    In the competitive global market place, aerospace companies are forced to deliver the right products to the right market, with the right cost, and at the right time. However, the rapid development of technologies and new business opportunities, such as mergers, acquisitions, supply chain management, etc., have dramatically increased the complexity of designing an aircraft. Therefore, the pressure to reduce design cycle time and cost is enormous. One way to solve such a dilemma is to develop and apply advanced engineering environments (AEEs), which are distributed collaborative virtual design environments linking researchers, technologists, designers, etc., together by incorporating application tools and advanced computational, communications, and networking facilities. Aircraft conceptual design, as the first design stage, provides major opportunity to compress design cycle time and is the cheapest place for making design changes. However, traditional aircraft conceptual design programs, which are monolithic programs, cannot provide satisfactory functionality to meet new design requirements due to the lack of domain flexibility and analysis scalability. Therefore, we are in need of the next generation aircraft conceptual design environment (NextADE). To build the NextADE, the framework and the data management problem are two major problems that need to be addressed at the forefront. Solving these two problems, particularly the data management problem, is the focus of this research. In this dissertation, in light of AEEs, a distributed object-oriented framework is firstly formulated and tested for the NextADE. In order to improve interoperability and simplify the integration of heterogeneous application tools, data management is one of the major problems that need to be tackled. To solve this problem, taking into account the characteristics of aircraft conceptual design data, a robust, extensible object-oriented data model is then proposed according to the

  6. Design of aircraft turbine fan drive gear transmission system (United States)

    Dent, E.; Hirsch, R. A.; Peterson, V. W.


    The following basic types of gear reduction concepts were studied as being feasible power train systems for a low-bypass-ratio, single-spool, geared turbofan engine for general aircraft use: (1) single-stage external-internal reduction, (2) gears (offset shafting), (3) multiple compound idler gear system (concentric shafting), and (4) star gear planetary system with internal ring gear final output member (concentric shafting-counterrotation). In addition, studies were made of taking the accessories drive power off both the high-speed and low-speed shafting, using either face gears or spiral bevel gears. Both antifriction and sleeve-type bearings were considered for the external-internal and star-planet reduction concepts.

  7. Numerical continuation and bifurcation analysis in aircraft design: an industrial perspective. (United States)

    Sharma, Sanjiv; Coetzee, Etienne B; Lowenberg, Mark H; Neild, Simon A; Krauskopf, Bernd


    Bifurcation analysis is a powerful method for studying the steady-state nonlinear dynamics of systems. Software tools exist for the numerical continuation of steady-state solutions as parameters of the system are varied. These tools make it possible to generate 'maps of solutions' in an efficient way that provide valuable insight into the overall dynamic behaviour of a system and potentially to influence the design process. While this approach has been employed in the military aircraft control community to understand the effectiveness of controllers, the use of bifurcation analysis in the wider aircraft industry is yet limited. This paper reports progress on how bifurcation analysis can play a role as part of the design process for passenger aircraft.

  8. Application of Adjoint Methodology to Supersonic Aircraft Design Using Reversed Equivalent Areas (United States)

    Rallabhandi, Sriram K.


    This paper presents an approach to shape an aircraft to equivalent area based objectives using the discrete adjoint approach. Equivalent areas can be obtained either using reversed augmented Burgers equation or direct conversion of off-body pressures into equivalent area. Formal coupling with CFD allows computation of sensitivities of equivalent area objectives with respect to aircraft shape parameters. The exactness of the adjoint sensitivities is verified against derivatives obtained using the complex step approach. This methodology has the benefit of using designer-friendly equivalent areas in the shape design of low-boom aircraft. Shape optimization results with equivalent area cost functionals are discussed and further refined using ground loudness based objectives.

  9. Thermal design for areas of interference heating on actively cooled hypersonic aircraft (United States)

    Herring, R. L.; Stone, J. E.


    Numerous actively cooled panel design alternatives for application in regions on high speed aircraft that are subject to interference heating effects were studied. Candidate design concepts were evaluated using mass, producibility, reliability and inspectability/maintainability as figures of merit. Three design approaches were identified as superior within certain regimes of the matrix of design heating conditions considered. Only minor modifications to basic actively cooled panel design are required to withstand minor interference heating effects. Designs incorporating internally finned coolant tubes to augment heat transfer are recommended for moderate design heating conditions. At severe heating conditions, an insulated panel concept is required.

  10. Practices to identify and preclude adverse Aircraft-and-Rotorcraft-Pilot Couplings - A design perspective (United States)

    Pavel, Marilena D.; Masarati, Pierangelo; Gennaretti, Massimo; Jump, Michael; Zaichik, Larisa; Dang-Vu, Binh; Lu, Linghai; Yilmaz, Deniz; Quaranta, Giuseppe; Ionita, Achim; Serafini, Jacopo


    Understanding, predicting and supressing the inadvertent aircraft oscillations caused by Aircraft/Rotorcraft Pilot Couplings (A/RPC) is a challenging problem for designers. These are potential instabilities that arise from the effort of controlling aircraft with high response actuation systems. The present paper reviews, updates and discusses desirable practices to be used during the design process for unmasking A/RPC phenomena. These practices are stemming from the European Commission project ARISTOTEL Aircraft and Rotorcraft Pilot Couplings - Tools and Techniques for Alleviation and Detection (2010-2013) and are mainly related to aerodynamic and structural modelling of the aircraft/rotorcraft, pilot modelling and A/RPC prediction criteria. The paper proposes new methodologies for precluding adverse A/RPCs events taking into account the aeroelasticity of the structure and pilot biodynamic interaction. It is demonstrated that high-frequency accelerations due to structural elasticity cause negative effects on pilot control, since they lead to involuntary body and limb-manipulator system displacements and interfere with pilot's deliberate control activity (biodynamic interaction) and, finally, worsen handling quality ratings.

  11. Improving aircraft conceptual design - A PHIGS interactive graphics interface for ACSYNT (United States)

    Wampler, S. G.; Myklebust, A.; Jayaram, S.; Gelhausen, P.


    A CAD interface has been created for the 'ACSYNT' aircraft conceptual design code that permits the execution and control of the design process via interactive graphics menus. This CAD interface was coded entirely with the new three-dimensional graphics standard, the Programmer's Hierarchical Interactive Graphics System. The CAD/ACSYNT system is designed for use by state-of-the-art high-speed imaging work stations. Attention is given to the approaches employed in modeling, data storage, and rendering.

  12. A Conceptual Design and Optimization Method for Blended-Wing-Body Aircraft

    NARCIS (Netherlands)

    Vos, R.; Van Dommelen, J.


    This paper details a new software tool to aid in the conceptual design of blended-wingbody aircraft. The tool consists of four main modules. In the preliminary sizing model a class I estimate of the maximum take-off weight, wing loading, and thrust-to-weight ratio is calculated. This information is

  13. Design for aircraft engine multi-objective controllers with switching characteristics

    Directory of Open Access Journals (Sweden)

    Liu Xiaofeng


    Full Text Available The aircraft engine multi-loop control system is described and the switching control theory is introduced to solve the regulating and protecting control problems in this paper. The aircraft engine multi-loop control system is firstly described and the control problems are formulated. Secondly, the theory of the smooth switching control is devoted and a new extended scheme for the smooth switching of a switched control system is introduced. Then, for the key technologies of aero-engines switching control, a design algorithm is presented which can determine which candidate controller should be put in feedback with the plant to achieve a desired performance and the procedure to design the aircraft engine multi-loop control system is detailed. The switching performance objectives and the switching scheme are given and a family of PID controllers and compensators is designed. The simulation shows that using the switching control design method can not only improve the dynamic performance of the aircraft engine control system and reduce the switching times, but also guarantee the stability in some peculiar occasions.

  14. Numerical Aircraft Design Using 3-D Transonic Analysis with Optimization. Volume I. Executive Summary. (United States)


    spanl]der designs with thick wings, and winglets for transport-category aircraft; and, (2) swept forward wings, variable camber wings with direct...Engines o Composite Materials o Active Controls The performance improvement as reflected in reduced fuel and gross weight brought about by each of the

  15. Design for aircraft engine multi-objective controllers with switching characteristics

    Institute of Scientific and Technical Information of China (English)

    Liu Xiaofeng; Shi Jing; Qi Yiwen; Yuan Ye


    The aircraft engine multi-loop control system is described and the switching control theory is introduced to solve the regulating and protecting control problems in this paper. The aircraft engine multi-loop control system is firstly described and the control problems are formu-lated. Secondly, the theory of the smooth switching control is devoted and a new extended scheme for the smooth switching of a switched control system is introduced. Then, for the key technologies of aero-engines switching control, a design algorithm is presented which can determine which candidate controller should be put in feedback with the plant to achieve a desired performance and the procedure to design the aircraft engine multi-loop control system is detailed. The switching performance objectives and the switching scheme are given and a family of PID controllers and compensators is designed. The simulation shows that using the switching control design method can not only improve the dynamic performance of the aircraft engine control system and reduce the switching times, but also guarantee the stability in some peculiar occasions.

  16. Flying qualities design criteria applicable to supersonic cruise aircraft (United States)

    Chalk, C. R.


    A comprehensive set of flying qualities design criteria was prepared for use in the supersonic cruise research program. The framework for stating the design criteria is established and design criteria are included which address specific failures, approach to dangerous flight conditions, flight at high angle of attack, longitudinal and lateral directional stability and control, the primary flight control system, and secondary flight controls. Examples are given of lateral directional design criteria limiting lateral accelerations at the cockpit, time to roll through 30 deg of bank, and time delay in the pilot's command path. Flight test data from the Concorde certification program are used to substantiate a number of the proposed design criteria.

  17. An analytical sensitivity method for use in integrated aeroservoelastic aircraft design (United States)

    Gilbert, Michael G.


    Interdisciplinary analysis capabilities have been developed for aeroservoelastic aircraft and large flexible spacecraft, but the requisite integrated design methods are only beginning to be developed. One integrated design method which has received attention is based on hierarchal problem decompositions, optimization, and design sensitivity analyses. This paper highlights a design sensitivity analysis method for Linear Quadratic Gaussian (LQG) optimal control laws, enabling the use of LQG techniques in the hierarchal design methodology. The LQG sensitivity analysis method calculates the change in the optimal control law and resulting controlled system responses due to changes in fixed design integration parameters using analytical sensitivity equations. Numerical results of a LQG design sensitivity analysis for a realistic aeroservoelastic aircraft example are presented. In this example, the sensitivity of the optimal control law and aircraft response for various parameters such as wing bending natural frequency is determined. The sensitivity results computed from the analytical expressions are used to estimate changes in response resulting from changes in the parameters. Comparisons of the estimates with exact calculated responses show they are reasonably accurate for + or - 15 percent changes in the parameters. Evaluation of the analytical expressions is computationally faster than equivalent finite difference calculations.

  18. Aircraft Conceptual Design and Risk Analysis Using Physics-Based Noise Prediction (United States)

    Olson, Erik D.; Mavris, Dimitri N.


    An approach was developed which allows for design studies of commercial aircraft using physics-based noise analysis methods while retaining the ability to perform the rapid trade-off and risk analysis studies needed at the conceptual design stage. A prototype integrated analysis process was created for computing the total aircraft EPNL at the Federal Aviation Regulations Part 36 certification measurement locations using physics-based methods for fan rotor-stator interaction tones and jet mixing noise. The methodology was then used in combination with design of experiments to create response surface equations (RSEs) for the engine and aircraft performance metrics, geometric constraints and take-off and landing noise levels. In addition, Monte Carlo analysis was used to assess the expected variability of the metrics under the influence of uncertainty, and to determine how the variability is affected by the choice of engine cycle. Finally, the RSEs were used to conduct a series of proof-of-concept conceptual-level design studies demonstrating the utility of the approach. The study found that a key advantage to using physics-based analysis during conceptual design lies in the ability to assess the benefits of new technologies as a function of the design to which they are applied. The greatest difficulty in implementing physics-based analysis proved to be the generation of design geometry at a sufficient level of detail for high-fidelity analysis.

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

    Institute of Scientific and Technical Information of China (English)

    Wang Yu; Yin Hailian; Zhang Shuai; Yu Xiongqing


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

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

    Directory of Open Access Journals (Sweden)

    Wang Yu


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

  1. Aircraft wing structural detail design (wing, aileron, flaps, and subsystems) (United States)

    Downs, Robert; Zable, Mike; Hughes, James; Heiser, Terry; Adrian, Kenneth


    The goal of this project was to design, in detail, the wing, flaps, and ailerons for a primary flight trainer. Integrated in this design are provisions for the fuel system, the electrical system, and the fuselage/cabin carry-through interface structure. This conceptual design displays the general arrangement of all major components in the wing structure, taking into consideration the requirements set forth by the appropriate sections of Federal Aviation Regulation Part 23 (FAR23) as well as those established in the statement of work.

  2. Current Research in Aircraft Tire Design and Performance (United States)

    Tanner, J. A.; Mccarthy, J. L.; Clark, S. K.


    A review of the tire research programs which address the various needs identified by landing gear designers and airplane users is presented. The experimental programs are designed to increase tire tread lifetimes, relate static and dynamic tire properties, establish the tire hydroplaning spin up speed, study gear response to tire failures, and define tire temperature profiles during taxi, braking, and cornering operations. The analytical programs are aimed at providing insights into the mechanisms of heat generation in rolling tires and developing the tools necessary to streamline the tire design process and to aid in the analysis of landing gear problems.

  3. Synthesis from Design Requirements of a Hybrid System for Transport Aircraft Longitudinal Control. Volume 1 (United States)

    Hynes, Charles S.; Hardy, Gordon H.; Sherry, Lance


    Volume I of this report presents a new method for synthesizing hybrid systems directly from design requirements, and applies the method to design of a hybrid system for longitudinal control of transport aircraft. The resulting system satisfies general requirement for safety and effectiveness specified a priori, enabling formal validation to be achieved. Volume II contains seven appendices intended to make the report accessible to readers with backgrounds in human factors, fli ght dynamics and control. and formal logic. Major design goals are (1) system desi g n integrity based on proof of correctness at the design level, (2), significant simplification and cost reduction in system development and certification, and (3) improved operational efficiency, with significant alleviation of human-factors problems encountered by pilots in current transport aircraft. This report provides for the first time a firm technical basis for criteria governing design and certification of avionic systems for transport aircraft. It should be of primary interest to designers of next-generation avionic systems.

  4. Design and Evaluation of a Wireless Sensor Network Based Aircraft Strength Testing System

    Directory of Open Access Journals (Sweden)

    Yang Wang


    Full Text Available The verification of aerospace structures, including full-scale fatigue and static test programs, is essential for structure strength design and evaluation. However, the current overall ground strength testing systems employ a large number of wires for communication among sensors and data acquisition facilities. The centralized data processing makes test programs lack efficiency and intelligence. Wireless sensor network (WSN technology might be expected to address the limitations of cable-based aeronautical ground testing systems. This paper presents a wireless sensor network based aircraft strength testing (AST system design and its evaluation on a real aircraft specimen. In this paper, a miniature, high-precision, and shock-proof wireless sensor node is designed for multi-channel strain gauge signal conditioning and monitoring. A cluster-star network topology protocol and application layer interface are designed in detail. To verify the functionality of the designed wireless sensor network for strength testing capability, a multi-point WSN based AST system is developed for static testing of a real aircraft undercarriage. Based on the designed wireless sensor nodes, the wireless sensor network is deployed to gather, process, and transmit strain gauge signals and monitor results under different static test loads. This paper shows the efficiency of the wireless sensor network based AST system, compared to a conventional AST system.

  5. Celebrating 100 Years of Flight: Testing Wing Designs in Aircraft (United States)

    Pugalee, David K.; Nusinov, Chuck; Giersch, Chris; Royster, David; Pinelli, Thomas E.


    This article describes an investigation involving several designs of airplane wings in trial flight simulations based on a NASA CONNECT program. Students' experiences with data collection and interpretation are highlighted. (Contains 5 figures.)

  6. A systematic method of smooth switching LPV controllers design for a morphing aircraft

    Institute of Scientific and Technical Information of China (English)

    Jiang Weilai a; Dong Chaoyang a; Wang Qing b


    This paper is concerned with a systematic method of smooth switching linear parameter-varying (LPV) controllers design for a morphing aircraft with a variable wing sweep angle. The morphing aircraft is modeled as an LPV system, whose scheduling parameter is the variation rate of the wing sweep angle. By dividing the scheduling parameter set into subsets with overlaps, output feedback controllers which consider smooth switching are designed and the controllers in over-lapped subsets are interpolated from two adjacent subsets. A switching law without constraint on the average dwell time is obtained which makes the conclusion less conservative. Furthermore, a systematic algorithm is developed to improve the efficiency of the controllers design process. The parameter set is divided into the fewest subsets on the premise that the closed-loop system has a desired performance. Simulation results demonstrate the effectiveness of this approach.

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

    Directory of Open Access Journals (Sweden)

    P.S. Subramanyam


    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.

  8. A systematic method of smooth switching LPV controllers design for a morphing aircraft

    Directory of Open Access Journals (Sweden)

    Jiang Weilai


    Full Text Available This paper is concerned with a systematic method of smooth switching linear parameter-varying (LPV controllers design for a morphing aircraft with a variable wing sweep angle. The morphing aircraft is modeled as an LPV system, whose scheduling parameter is the variation rate of the wing sweep angle. By dividing the scheduling parameter set into subsets with overlaps, output feedback controllers which consider smooth switching are designed and the controllers in overlapped subsets are interpolated from two adjacent subsets. A switching law without constraint on the average dwell time is obtained which makes the conclusion less conservative. Furthermore, a systematic algorithm is developed to improve the efficiency of the controllers design process. The parameter set is divided into the fewest subsets on the premise that the closed-loop system has a desired performance. Simulation results demonstrate the effectiveness of this approach.

  9. The design and manufacture of a remotely piloted aircraft

    Directory of Open Access Journals (Sweden)

    Cosmin PESCARUS


    Full Text Available The article is a compilation of data regarding the process of designing an UAV wing, generally speaking, and an iteration of the stress calculations made during the research. Therefore, we use the best materials and a design that fits the necessities and requirements of such an airplane. The purpose of the UAV is to have a precise goal, namely to be used by the authorities for the people. Example: flying at low height for the surveillance of a large forest fire or a highway, or even for collecting data regarding the air quality and the percentage of noxious particles in different urban and nonurban areas.

  10. Rapid Euler CFD for High-Performance Aircraft Design (United States)

    Charlton, Eric F.


    The goal here was to present one approach to rapid CFD for S&C using an unstructured inviscid method, in order to eventually assess S&C properties as early in the design process as possible. Specific results are presented regarding time, accuracy (as compared to a baseline wind tunnel database) and simplicity for the user. For COMSAC, it s more important to talk about the "specifications" required by Advanced Design and S&C, as well as how the CFD results can be combined for envelope evaluation.

  11. Design of a Low-Cost Easy-to-Fly STOL Ultralight Aircraft in Composite Material

    Directory of Open Access Journals (Sweden)

    D. P. Coiro


    Full Text Available The paper deals with the design of an aircraft, starting from a market survey, the conceptual design loop and the preliminary choice of dimensions, and leading to the detailed design of efficient high-lift systems and a low-drag fuselage shape. Technological challenges regarding the design of low-cost systems for flap/slat retraction and a simple wing folding system are highlighted. Aiming at an efficient optimization algorithm, we developed a new integration technique between CAD, aerodynamic and structural numerical calculation. Examples deriving from this new approach are presented. 

  12. Modal control theory and application to aircraft lateral handling qualities design (United States)

    Srinathkumar, S.


    A multivariable synthesis procedure based on eigenvalue/eigenvector assignment is reviewed and is employed to develop a systematic design procedure to meet the lateral handling qualities design objectives of a fighter aircraft over a wide range of flight conditions. The closed loop modal characterization developed provides significant insight into the design process and plays a pivotal role in the synthesis of robust feedback systems. The simplicity of the synthesis algorithm yields an efficient computer aided interactive design tool for flight control system synthesis.

  13. Design of an Intelligent Tutoring System for Aircraft Recognition (United States)


    auspices of the U S Dearirrient of Energy \\B Tr[ O Los Alamos National Laboratory Los Alamos,New Mexico 87545 , AM W 636 F" ST~b NoMstl2 Li 093...student model, and a communication Tail flats mid-mounted on fuselage, protocol. Storyboards and screen design are then or swept-back with rounded tips

  14. The multidisciplinary design optimization of a distributed propulsion blended-wing-body aircraft (United States)

    Ko, Yan-Yee Andy

    The purpose of this study is to examine the multidisciplinary design optimization (MDO) of a distributed propulsion blended-wing-body (BWB) aircraft. The BWB is a hybrid shape resembling a flying wing, placing the payload in the inboard sections of the wing. The distributed propulsion concept involves replacing a small number of large engines with many smaller engines. The distributed propulsion concept considered here ducts part of the engine exhaust to exit out along the trailing edge of the wing. The distributed propulsion concept affects almost every aspect of the BWB design. Methods to model these effects and integrate them into an MDO framework were developed. The most important effect modeled is the impact on the propulsive efficiency. There has been conjecture that there will be an increase in propulsive efficiency when there is blowing out of the trailing edge of a wing. A mathematical formulation was derived to explain this. The formulation showed that the jet 'fills in' the wake behind the body, improving the overall aerodynamic/propulsion system, resulting in an increased propulsive efficiency. The distributed propulsion concept also replaces the conventional elevons with a vectored thrust system for longitudinal control. An extension of Spence's Jet Flap theory was developed to estimate the effects of this vectored thrust system on the aircraft longitudinal control. It was found to provide a reasonable estimate of the control capability of the aircraft. An MDO framework was developed, integrating all the distributed propulsion effects modeled. Using a gradient based optimization algorithm, the distributed propulsion BWB aircraft was optimized and compared with a similarly optimized conventional BWB design. Both designs are for an 800 passenger, 0.85 cruise Mach number and 7000 nmi mission. The MDO results found that the distributed propulsion BWB aircraft has a 4% takeoff gross weight and a 2% fuel weight. Both designs have similar planform shapes

  15. A Framework for Preliminary Design of Aircraft Structures Based on Process Information. Part 1 (United States)

    Rais-Rohani, Masoud


    This report discusses the general framework and development of a computational tool for preliminary design of aircraft structures based on process information. The described methodology is suitable for multidisciplinary design optimization (MDO) activities associated with integrated product and process development (IPPD). The framework consists of three parts: (1) product and process definitions; (2) engineering synthesis, and (3) optimization. The product and process definitions are part of input information provided by the design team. The backbone of the system is its ability to analyze a given structural design for performance as well as manufacturability and cost assessment. The system uses a database on material systems and manufacturing processes. Based on the identified set of design variables and an objective function, the system is capable of performing optimization subject to manufacturability, cost, and performance constraints. The accuracy of the manufacturability measures and cost models discussed here depend largely on the available data on specific methods of manufacture and assembly and associated labor requirements. As such, our focus in this research has been on the methodology itself and not so much on its accurate implementation in an industrial setting. A three-tier approach is presented for an IPPD-MDO based design of aircraft structures. The variable-complexity cost estimation methodology and an approach for integrating manufacturing cost assessment into design process are also discussed. This report is presented in two parts. In the first part, the design methodology is presented, and the computational design tool is described. In the second part, a prototype model of the preliminary design Tool for Aircraft Structures based on Process Information (TASPI) is described. Part two also contains an example problem that applies the methodology described here for evaluation of six different design concepts for a wing spar.

  16. 飞行器结构设计特点及演变%Aircraft Structural Design Features and Evolution

    Institute of Scientific and Technical Information of China (English)

    赵智姝; 李伟; 李映红


    飞行器结构设计是飞行器设计中重要的组成部分,本文从飞行器结构设计的要求出发、详细介绍了机身、机翼、尾翼的设计特点,总结了飞行器结构设计的演变趋势,对飞行器设计人员和维修人员具有一定的参考价值。%Structural design is a very important part of aircraft design . Starting from aircraft structural design requirement , this paper introduces in detail the design features of fuselage, wing, and empennage, and summarizes evolution trends of aircraft structural design , which has a certain reference value for aircraft design and maintenance personnel .

  17. Practical Application of Finite Element Analysis to Aircraft Structural Design (United States)


    analysis and mechanical properties, including the equivalent inclusion method, elastic constants and internal friction in composites, finite element...intensity factors are not available. The inclusion of fracture constraints in the automated design process is a logical extension of present structural...September 30-Dctober 3, 1975, Proceedings. Volume 1. (A78-19026 06-01) Turin, Libreria Editrice Universitaria Levrotto e Bella, 1975, p. 291-300. In

  18. Design, fabrication and testing of a liquid hydrogen fuel tank for a long duration aircraft (United States)

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


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

  19. Design and test of aircraft engine isolators for reduced interior noise (United States)

    Unruh, J. F.; Scheidt, D. C.


    Improved engine vibration isolation was proposed to be the most weight and cost efficient retrofit structure-borne noise control measure for single engine general aviation aircraft. A study was carried out the objectives: (1) to develop an engine isolator design specification for reduced interior noise transmission, (2) select/design candidate isolators to meet a 15 dB noise reduction design goal, and (3) carry out a proof of concept evaluation test. Analytical model of the engine, vibration isolators and engine mount structure were coupled to an empirical model of the fuselage for noise transmission evaluation. The model was used to develop engine isolator dynamic properties design specification for reduced noise transmission. Candidate isolators ere chosen from available product literature and retrofit to a test aircraft. A laboratory based test procedure was then developed to simulate engine induced noise transmission in the aircraft for a proof of concept evaluation test. Three candidate isolator configurations were evaluated for reduced structure-borne noise transmission relative to the original equipment isolators.

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

    Directory of Open Access Journals (Sweden)

    Pezhman Mardanpour


    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.

  1. Fault Tolerant Control Design for the Longitudinal Aircraft Dynamics using Quantitative Feedback Theory


    Ossmann, Daniel


    Flight control laws of modern aircraft are scheduled with respect to flight point parameters. The loss of the air data measurement system implies inevitably the loss of relevant scheduling information. A strategy to design a fault tolerant longitudinal flight control system is proposed which can accommodate the total loss of the angle of attack and the calibrated airspeed measurements. In this scenario the described robust longitudinal control law is employed ensuring a control performance ...

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


    P. S. Subramanyam


    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...

  3. Human engineering problems in the operation of controls and the design of aircraft instruments

    Directory of Open Access Journals (Sweden)

    W.T.V. Adiseshiah


    Full Text Available "Speed and accuracy in performance are major considerations in the design of man-machine systems which involve displays for presenting information to the senses, and controls for human use. Sensory capacity, mobility and muscle strength, mental stamina, and capacity for team work are psychological factors which call for appropriate attention. In the design and selection of control devices, it is important to consider size and shape, location and action of the control devices. These should be compatible with the element to be controlled. four matters call for attention: firstly, control dimensions should take into consideration the normal hand grasp limitations of the operator. Secondly, knob of the controls should be suitably shape coded so as to forestall inadvertent operation of wrong controls. Thirdly, controls which have to be used most often should be placed within convenient reach of the operator. Fourthly, the human operator cannot be expected to perform at maximum capacity for any great length of time. Correctly positioned power controls are being increasingly used in present day aircraft. In the design of aircraft instruments and the layout of flying panels, the limitations of the human operator, emergencies which are likely to arise during flight, and imperfections in the indications of instruments need to be taken into account. The design of aircraft instruments such as the altimeter, the air speed indicator, and the artificial horizon, are being improved from time to time so as to meet the new requirements in flying. Single and multiple instrument combinations have effected a saving of time in locating parts of a total picture, e.g. the composite indication of fuel state in modern aircraft. Many unsolved problems still remain with regard to the use of certain items such as the aiming, photographic and oxygen equipments. "

  4. Conceptual Design and Structural Optimization of NASA Environmentally Responsible Aviation (ERA) Hybrid Wing Body Aircraft (United States)

    Quinlan, Jesse R.; Gern, Frank H.


    Simultaneously achieving the fuel consumption and noise reduction goals set forth by NASA's Environmentally Responsible Aviation (ERA) project requires innovative and unconventional aircraft concepts. In response, advanced hybrid wing body (HWB) aircraft concepts have been proposed and analyzed as a means of meeting these objectives. For the current study, several HWB concepts were analyzed using the Hybrid wing body Conceptual Design and structural optimization (HCDstruct) analysis code. HCDstruct is a medium-fidelity finite element based conceptual design and structural optimization tool developed to fill the critical analysis gap existing between lower order structural sizing approaches and detailed, often finite element based sizing methods for HWB aircraft concepts. Whereas prior versions of the tool used a half-model approach in building the representative finite element model, a full wing-tip-to-wing-tip modeling capability was recently added to HCDstruct, which alleviated the symmetry constraints at the model centerline in place of a free-flying model and allowed for more realistic center body, aft body, and wing loading and trim response. The latest version of HCDstruct was applied to two ERA reference cases, including the Boeing Open Rotor Engine Integration On an HWB (OREIO) concept and the Boeing ERA-0009H1 concept, and results agreed favorably with detailed Boeing design data and related Flight Optimization System (FLOPS) analyses. Following these benchmark cases, HCDstruct was used to size NASA's ERA HWB concepts and to perform a related scaling study.

  5. Application of modern control design methodology to oblique wing research aircraft (United States)

    Vincent, James H.


    A Linear Quadratic Regulator synthesis technique was used to design an explicit model following control system for the Oblique Wing Research Aircraft (OWRA). The forward path model (Maneuver Command Generator) was designed to incorporate the desired flying qualities and response decoupling. The LQR synthesis was based on the use of generalized controls, and it was structured to provide a proportional/integral error regulator with feedforward compensation. An unexpected consequence of this design approach was the ability to decouple the control synthesis into separate longitudinal and lateral directional designs. Longitudinal and lateral directional control laws were generated for each of the nine design flight conditions, and gain scheduling requirements were addressed. A fully coupled 6 degree of freedom open loop model of the OWRA along with the longitudinal and lateral directional control laws was used to assess the closed loop performance of the design. Evaluations were performed for each of the nine design flight conditions.

  6. Gust response modeling and alleviation scheme design for an elastic aircraft

    Institute of Scientific and Technical Information of China (English)


    Time-domain approaches are presented for analysis of the dynamic response of aeroservoelastic systems to atmospheric gust excitations. The continuous and discrete gust inputs are defined in the time domain. The time-domain approach to continuous gust response uses a state-space formulation that requires the frequency-dependent aerodynamic coefficients to be approximated with the rational function of a Laplace variable. A hybrid method which combines the Fourier transform and time-domain approaches is used to calculate discrete gust response. The purpose of this approach is to obtain a time-domain state-space model without using rational function approximation of the gust columns. Three control schemes are designed for gust alleviation on an elastic aircraft, and three control surfaces are used: aileron, elevator and spoiler. The signals from the rate of pitch angle gyroscope or angle of attack sensor are sent to the elevator while the signals from accelerometers at the wing tip and center of gravity of the aircraft are sent to the aileron and spoiler, respectively. All the control laws are based on classical control theory. The results show that acceleration at the center of gravity of the aircraft and bending-moment at the wing-root section are mainly excited by rigid modes of the aircraft and the accelerations at the wing-tip are mainly excited by elastic modes of the aircraft. All the three control schemes can be used to alleviate the wing-root moments and the accelerations. The gust response can be alleviated using control scheme 3, in which the spoiler is used as a control surface, but the effects are not as good as those of control schemes 1 and 2.

  7. Aerodynamic Modeling of Transonic Aircraft Using Vortex Lattice Coupled with Transonic Small Disturbance for Conceptual Design (United States)

    Chaparro, Daniel; Fujiwara, Gustavo E. C.; Ting, Eric; Nguyen, Nhan


    The need to rapidly scan large design spaces during conceptual design calls for computationally inexpensive tools such as the vortex lattice method (VLM). Although some VLM tools, such as Vorview have been extended to model fully-supersonic flow, VLM solutions are typically limited to inviscid, subcritical flow regimes. Many transport aircraft operate at transonic speeds, which limits the applicability of VLM for such applications. This paper presents a novel approach to correct three-dimensional VLM through coupling of two-dimensional transonic small disturbance (TSD) solutions along the span of an aircraft wing in order to accurately predict transonic aerodynamic loading and wave drag for transport aircraft. The approach is extended to predict flow separation and capture the attenuation of aerodynamic forces due to boundary layer viscosity by coupling the TSD solver with an integral boundary layer (IBL) model. The modeling framework is applied to the NASA General Transport Model (GTM) integrated with a novel control surface known as the Variable Camber Continuous Trailing Edge Flap (VCCTEF).

  8. Analytical study of interior noise control by fuselage design techniques on high-speed, propeller-driven aircraft (United States)

    Revell, J. D.; Balena, F. J.; Koval, L. R.


    The acoustical treatment mass penalties required to achieve an interior noise level of 80 dBA for high speed, fuel efficient propfan-powered aircraft are determined. The prediction method used is based on theory developed for the outer shell dynamics, and a modified approach for add-on noise control element performance. The present synthesis of these methods is supported by experimental data. Three different sized aircraft are studied, including a widebody, a narrowbody and a business sized aircraft. Noise control penalties are calculated for each aircraft for two kinds of noise control designs: add-on designs, where the outer wall structure cannot be changed, and advanced designs where the outer wall stiffness level and the materials usage can be altered. For the add-on designs, the mass penalties range from 1.7 to 2.4 percent of the takeoff gross weight (TOGW) of the various aircraft, similar to preliminary estimates. Results for advanced designs show significant reductions of the mass penalties. For the advanced aluminum designs the penalties are 1.5% of TOGW, and for an all composite aircraft the penalties range from 0.74 to 1.4% of TOGW.

  9. Compilation of Energy Efficient Concepts in Advanced Aircraft Design and Operations. Volume 2. Abstract Data Base (United States)


    60 B.2 PROPULSION TECNOLOGY B-2.1 GAS TURBINES B.2.1.i NAVY FUNDED I B2-1I NADC-79239-60 B.2.1.1.l SSIE: CQN 975316 3/79 to Cont Colorado State...which are also beter for fuel and operating cost economy) push the desired bypass ratio up further. Effects on fuel consumption of design features include high-aspect-ratio wings, thickness ratio and range. It is conclu&d that wing aspect ratios of future aircraft are I - push of

  10. Artificial Neural Networks Applications: from Aircraft Design Optimization to Orbiting Spacecraft On-board Environment Monitoring (United States)

    Jules, Kenol; Lin, Paul P.


    This paper reviews some of the recent applications of artificial neural networks taken from various works performed by the authors over the last four years at the NASA Glenn Research Center. This paper focuses mainly on two areas. First, artificial neural networks application in design and optimization of aircraft/engine propulsion systems to shorten the overall design cycle. Out of that specific application, a generic design tool was developed, which can be used for most design optimization process. Second, artificial neural networks application in monitoring the microgravity quality onboard the International Space Station, using on-board accelerometers for data acquisition. These two different applications are reviewed in this paper to show the broad applicability of artificial intelligence in various disciplines. The intent of this paper is not to give in-depth details of these two applications, but to show the need to combine different artificial intelligence techniques or algorithms in order to design an optimized or versatile system.

  11. Aircraft ride quality controller design using new robust root clustering theory for linear uncertain systems (United States)

    Yedavalli, R. K.


    The aspect of controller design for improving the ride quality of aircraft in terms of damping ratio and natural frequency specifications on the short period dynamics is addressed. The controller is designed to be robust with respect to uncertainties in the real parameters of the control design model such as uncertainties in the dimensional stability derivatives, imperfections in actuator/sensor locations and possibly variations in flight conditions, etc. The design is based on a new robust root clustering theory developed by the author by extending the nominal root clustering theory of Gutman and Jury to perturbed matrices. The proposed methodology allows to get an explicit relationship between the parameters of the root clustering region and the uncertainty radius of the parameter space. The current literature available for robust stability becomes a special case of this unified theory. The bounds derived on the parameter perturbation for robust root clustering are then used in selecting the robust controller.

  12. Exploring QDES as a Tool for Determining Limits of Achievable Performance in Aircraft Design (United States)


    Standard Feedback Diagram y: Sensed Outputs. Output signals that are accessible to the controller. These must be measurable. For the aircraft longitudinal axis...of an aircraft to pushover more than two or tbree g’s is not of great operational importance. 4.3 Aircraft Model The aircraft longitudinal model used...Appendix (A), section (A.1). 4.4 Inner Loop Pitch SAS Theory Control of an aircraft longitudinal axis which exhibits the classical Short Period and Phugoid

  13. Design and evaluation of an onboard computer-based information system for aircraft (United States)

    Rouse, S. H.; Rouse, W. B.; Hammer, J. M.


    Information seeking by human operators of technical systems is considered. Types of information and forms of presentation are discussed and important issues reviewed. This broad discussion provides a framework within which flight management is considered. The design of an onboard computer-based information system for aircraft is discussed. The aiding possibilities of a computer-based system are emphasized. Results of an experimental evaluation of a prototype system are presented. It is concluded that a computer-based information system can substantially lessen the frequency of human errors.

  14. New stabilization design for planar vertical take-off and landing aircrafts

    Institute of Scientific and Technical Information of China (English)


    This paper presents a new stabilizing control law for a planar vertical take-off and landing aircraft.The model is first transformed into an equivalent form,and then a control law consisting of a linear term and a saturated term is given for a related subsystem,with the saturation levels being assigned as large as possible.Compared to the existing saturation scheme in which all states are restricted by saturations,the design brings about a relatively fast convergence.The effectiveness and advantage of the d...

  15. Simulation and Flight Evaluation of a Parameter Estimation Input Design Method for Hybrid-Wing-Body Aircraft (United States)

    Taylor, Brian R.; Ratnayake, Nalin A.


    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.

  16. Design, Specification, and Synthesis of Aircraft Electric Power Systems Control Logic (United States)

    Xu, Huan

    Cyber-physical systems integrate computation, networking, and physical processes. Substantial research challenges exist in the design and verification of such large-scale, distributed sensing, actuation, and control systems. Rapidly improving technology and recent advances in control theory, networked systems, and computer science give us the opportunity to drastically improve our approach to integrated flow of information and cooperative behavior. Current systems rely on text-based specifications and manual design. Using new technology advances, we can create easier, more efficient, and cheaper ways of developing these control systems. This thesis will focus on design considerations for system topologies, ways to formally and automatically specify requirements, and methods to synthesize reactive control protocols, all within the context of an aircraft electric power system as a representative application area. This thesis consists of three complementary parts: synthesis, specification, and design. The first section focuses on the synthesis of central and distributed reactive controllers for an aircraft elec- tric power system. This approach incorporates methodologies from computer science and control. The resulting controllers are correct by construction with respect to system requirements, which are formulated using the specification language of linear temporal logic (LTL). The second section addresses how to formally specify requirements and introduces a domain-specific language for electric power systems. A software tool automatically converts high-level requirements into LTL and synthesizes a controller. The final sections focus on design space exploration. A design methodology is proposed that uses mixed-integer linear programming to obtain candidate topologies, which are then used to synthesize controllers. The discrete-time control logic is then verified in real-time by two methods: hardware and simulation. Finally, the problem of partial observability and

  17. Recent experience with multidisciplinary analysis and optimization in advanced aircraft design (United States)

    Dollyhigh, Samuel M.; Sobieszczanski-Sobieski, Jaroslaw


    The task of modern aircraft design has always been complicated due to the number of intertwined technical factors from the various engineering disciplines. Furthermore, this complexity has been rapidly increasing by the development of such technologies as aeroelasticity tailored materials and structures, active control systems, integrated propulsion/airframe controls, thrust vectoring, and so on. Successful designs that achieve maximum advantage from these new technologies require a thorough understanding of the physical phenomena and the interactions among these phenomena. A study commissioned by the Aeronautical Sciences and Evaluation Board of the National Research Council has gone so far as to identify technology integration as a new discipline from which many future aeronautical advancements will arise. Regardless of whether one considers integration as a new discipline or not, it is clear to all engineers involved in aircraft design and analysis that better methods are required. In the past, designers conducted parametric studies in which a relatively small number of principal characteristics were varied to determine the effect on design requirements which were themselves often diverse and contradictory. Once a design was chosen, it then passed through the various engineers' disciplines whose principal task was to make the chosen design workable. Working in a limited design space, the discipline expert sometimes improved the concept, but more often than not, the result was in the form of a penalty to make the original concept workable. If an insurmountable problem was encountered, the process began over. Most design systems that attempt to account for disciplinary interactions have large empirical elements and reliance on past experience is a poor guide in obtaining maximum utilizations of new technologies. Further compounding the difficulty of design is that as the aeronautical sciences have matured, the discipline specialist's area of research has generally

  18. A methodology for the efficient integration of transient constraints in the design of aircraft dynamic systems (United States)

    Phan, Leon L.

    The motivation behind this thesis mainly stems from previous work performed at Hispano-Suiza (Safran Group) in the context of the European research project "Power Optimised Aircraft". Extensive testing on the COPPER Bird RTM, a test rig designed to characterize aircraft electrical networks, demonstrated the relevance of transient regimes in the design and development of dynamic systems. Transient regimes experienced by dynamic systems may have severe impacts on the operation of the aircraft. For example, the switching on of a high electrical load might cause a network voltage drop inducing a loss of power available to critical aircraft systems. These transient behaviors are thus often regulated by dynamic constraints, requiring the dynamic signals to remain within bounds whose values vary with time. The verification of these peculiar types of constraints, which generally requires high-fidelity time-domain simulation, intervenes late in the system development process, thus potentially causing costly design iterations. The research objective of this thesis is to develop a methodology that integrates the verification of dynamic constraints in the early specification of dynamic systems. In order to circumvent the inefficiencies of time-domain simulation, multivariate dynamic surrogate models of the original time-domain simulation models are generated, building on a nonlinear system identification technique using wavelet neural networks (or wavenets), which allow the multiscale nature of transient signals to be captured. However, training multivariate wavenets can become computationally prohibitive as the number of design variables increases. Therefore, an alternate approach is formulated, in which dynamic surrogate models using sigmoid-based neural networks are used to emulate the transient behavior of the envelopes of the time-domain response. Thus, in order to train the neural network, the envelopes are extracted by first separating the scales of the dynamic response

  19. AP1000{sup R} design robustness against extreme external events - Seismic, flooding, and aircraft crash

    Energy Technology Data Exchange (ETDEWEB)

    Pfister, A.; Goossen, C.; Coogler, K.; Gorgemans, J. [Westinghouse Electric Company LLC, 1000 Westinghouse Drive, Cranberry Township, PA 16066 (United States)


    Both the International Atomic Energy Agency (IAEA) and the U.S. Nuclear Regulatory Commission (NRC) require existing and new nuclear power plants to conduct plant assessments to demonstrate the unit's ability to withstand external hazards. The events that occurred at the Fukushima-Dai-ichi nuclear power station demonstrated the importance of designing a nuclear power plant with the ability to protect the plant against extreme external hazards. The innovative design of the AP1000{sup R} nuclear power plant provides unparalleled protection against catastrophic external events which can lead to extensive infrastructure damage and place the plant in an extended abnormal situation. The AP1000 plant is an 1100-MWe pressurized water reactor with passive safety features and extensive plant simplifications that enhance construction, operation, maintenance and safety. The plant's compact safety related footprint and protection provided by its robust nuclear island structures prevent significant damage to systems, structures, and components required to safely shutdown the plant and maintain core and spent fuel pool cooling and containment integrity following extreme external events. The AP1000 nuclear power plant has been extensively analyzed and reviewed to demonstrate that it's nuclear island design and plant layout provide protection against both design basis and extreme beyond design basis external hazards such as extreme seismic events, external flooding that exceeds the maximum probable flood limit, and malicious aircraft impact. The AP1000 nuclear power plant uses fail safe passive features to mitigate design basis accidents. The passive safety systems are designed to function without safety-grade support systems (such as AC power, component cooling water, service water, compressed air or HVAC). The plant has been designed to protect systems, structures, and components critical to placing the reactor in a safe shutdown condition within the steel

  20. Subsonic Ultra Green Aircraft Research. Phase II - Volume I; Truss Braced Wing Design Exploration (United States)

    Bradley, Marty K.; Droney, Christopher K.; Allen, Timothy J.


    This report summarizes the Truss Braced Wing (TBW) work accomplished by the Boeing Subsonic Ultra Green Aircraft Research (SUGAR) team, consisting of Boeing Research and Technology, Boeing Commercial Airplanes, General Electric, Georgia Tech, Virginia Tech, NextGen Aeronautics, and Microcraft. A multi-disciplinary optimization (MDO) environment defined the geometry that was further refined for the updated SUGAR High TBW configuration. Airfoil shapes were tested in the NASA TCT facility, and an aeroelastic model was tested in the NASA TDT facility. Flutter suppression was successfully demonstrated using control laws derived from test system ID data and analysis models. Aeroelastic impacts for the TBW design are manageable and smaller than assumed in Phase I. Flutter analysis of TBW designs need to include pre-load and large displacement non-linear effects to obtain a reasonable match to test data. With the updated performance and sizing, fuel burn and energy use is reduced by 54% compared to the SUGAR Free current technology Baseline (Goal 60%). Use of the unducted fan version of the engine reduces fuel burn and energy by 56% compared to the Baseline. Technology development roadmaps were updated, and an airport compatibility analysis established feasibility of a folding wing aircraft at existing airports.

  1. Design Guidelines, Experimental Investigation and Numerical Analysis of a New Twin Engine Commuter Aircraft


    Corcione, Salvatore


    At the end of the year 2011, statistical data reports that the average age of general aviation registered aircraft is 46 years for single-engine piston powered aircraft and 15 years for single-engine turboprop aircraft. The average age for twin-engine 8-12 seats aircraft is 42 years for piston powered models and about 29 years for twin-engine turboprop commuter aircraft. These data show the need of a new aircraft model, also characterized by the application of new technologies like c...

  2. A Robust and Reliability-Based Optimization Framework for Conceptual Aircraft Wing Design (United States)

    Paiva, Ricardo Miguel

    A robustness and reliability based multidisciplinary analysis and optimization framework for aircraft design is presented. Robust design optimization and Reliability Based Design Optimization are merged into a unified formulation which streamlines the setup of optimization problems and aims at preventing foreseeable implementation issues in uncertainty based design. Surrogate models are evaluated to circumvent the intensive computations resulting from using direct evaluation in nondeterministic optimization. Three types of models are implemented in the framework: quadratic interpolation, regression Kriging and artificial neural networks. Regression Kriging presents the best compromise between performance and accuracy in deterministic wing design problems. The performance of the simultaneous implementation of robustness and reliability is evaluated using simple analytic problems and more complex wing design problems, revealing that performance benefits can still be achieved while satisfying probabilistic constraints rather than the simpler (and not as computationally intensive) robust constraints. The latter are proven to to be unable to follow a reliability constraint as uncertainty in the input variables increases. The computational effort of the reliability analysis is further reduced through the implementation of a coordinate change in the respective optimization sub-problem. The computational tool developed is a stand-alone application and it presents a user-friendly graphical user interface. The multidisciplinary analysis and design optimization tool includes modules for aerodynamics, structural, aeroelastic and cost analysis, that can be used either individually or coupled.

  3. Flight system design for a receiver aircraft to perform autonomous aerial refueling provided with relative position data link (United States)

    Awni, Kahtan A.

    An automatic aerial refueling system was developed that is capable of controlling the receiving aircraft to rendezvous, dock and station keep the receiver refueling probe in the tanker refueling probe. The automatic refueling system consisted of an active trajectory generator, a guidance system and a control system. The active trajectory generator continuously updated the commanded rendezvous trajectory to be flown by the receiver aircraft. This active trajectory generator concept incorporated design variables that the designer could use to specify the time sequence of the rendezvous and docking maneuver. The output of the trajectory generator was then the command to the flight systems guidance and control systems. To demonstrate this automatic aerial refueling system concept, a detailed design of the flight system algorithms was done for typical aerial refueling mission with a heavy jet tanker aircraft similar to the KC135 and the SIAI-Marchetti S-211 Jet Trainer as a receiver aircraft. The systems gains were selected to minimize the control surface activity while achieving adequate tracking. A simulation was developed that included the flight system algorithms, linear models of the receiver aircraft, atmospheric and tanker wake disturbance models. The performance of the aerial refueling system design was then evaluated in a batch computer simulator. The simulation study demonstrated results showed better disturbance rejection relative to the controller performance while minimizing the utilization of the control surfaces. Results also demonstrated the ability to schedule rendezvous.

  4. Aircraft conceptual design study of the canard and threesurface unconventional configurations for the purposes of reducing environmental impacts (United States)

    Desharnais, Olivier

    With a constant increase in the demand for air transport and today's high fuel price, the aerospace industry is actively searching for new operation methods and technologies to improve efficiency and to reduce the impact it has on the environment. Aircraft manufacturers are exploring many different ways of designing and building better airplanes. One of the considered methods is the use of unconventional aircraft configurations. The objective of this research is to study two configurations, the canard and three-surface, by applying them into a typical high-speed jet aircraft using the conceptual design tools for conventional aircraft available at Bombardier Aerospace (some of them have been modified and validated for the two configurations of interest). This included a weight estimation of the foreplane, an extensive validation of the aerodynamic tool, AVL, and a modification of a physics-based tail-sizing tool. The last tool was found necessary for an accurate foreplane/tailplane sizing, aircraft balancing, establishing the CG envelope and for the assessment of all stability and control requirements. Then, a canard aircraft comparable to the Bombardier research platform aircraft was designed. Final solutions were not obtained from a complete optimization because of some limitations in the design process. The preliminary results show an increase of fuel burn of 10%, leading to an increase of the environmental impacts. The theoretical advantage of not generating any download lift is clearly overwhelmed by the poor effectiveness of the high-lift system. The incapacity to reach a level of high-lift performance close to the one of conventional high-speed aircrafts mostly explains why the canard configuration was found to have no true benefits in this application. Even if no final solution of a three-surface aircraft was obtained in this research, this configuration was identified as being better than the canard case according to the information found in the literature

  5. Advanced turboprop testbed systems study. Volume 1: Testbed program objectives and priorities, drive system and aircraft design studies, evaluation and recommendations and wind tunnel test plans (United States)

    Bradley, E. S.; Little, B. H.; Warnock, W.; Jenness, C. M.; Wilson, J. M.; Powell, C. W.; Shoaf, L.


    The establishment of propfan technology readiness was determined and candidate drive systems for propfan application were identified. Candidate testbed aircraft were investigated for testbed aircraft suitability and four aircraft selected as possible propfan testbed vehicles. An evaluation of the four candidates was performed and the Boeing KC-135A and the Gulfstream American Gulfstream II recommended as the most suitable aircraft for test application. Conceptual designs of the two recommended aircraft were performed and cost and schedule data for the entire testbed program were generated. The program total cost was estimated and a wind tunnel program cost and schedule is generated in support of the testbed program.

  6. Subsonic Ultra Green Aircraft Research: Phase 2. Volume 2; Hybrid Electric Design Exploration (United States)

    Bradley, Marty K.; Droney, Christopher K.


    This report summarizes the hybrid electric concept design, analysis, and modeling work accomplished by the Boeing Subsonic Ultra Green Aircraft Research (SUGAR) team, consisting of Boeing Research and Technology, Boeing Commercial Airplanes, General Electric, and Georgia Tech.Performance and sizing tasks were conducted for hybrid electric versions of a conventional tube-and-wing aircraft and a hybrid wing body. The high wing Truss Braced Wing (TBW) SUGAR Volt was updated based on results from the TBW work (documented separately) and new engine performance models. Energy cost and acoustic analyses were conducted and technology roadmaps were updated for hybrid electric and battery technology. NOx emissions were calculated for landing and takeoff (LTO) and cruise. NPSS models were developed for hybrid electric components and tested using an integrated analysis of superconducting and non-superconducting hybrid electric engines. The hybrid electric SUGAR Volt was shown to produce significant emissions and fuel burn reductions beyond those achieved by the conventionally powered SUGAR High and was able to meet the NASA goals for fuel burn. Total energy utilization was not decreased but reduced energy cost can be achieved for some scenarios. The team was not able to identify a technology development path to meet NASA's noise goals

  7. Maximum likelihood identification and optimal input design for identifying aircraft stability and control derivatives (United States)

    Stepner, D. E.; Mehra, R. K.


    A new method of extracting aircraft stability and control derivatives from flight test data is developed based on the maximum likelihood cirterion. It is shown that this new method is capable of processing data from both linear and nonlinear models, both with and without process noise and includes output error and equation error methods as special cases. The first application of this method to flight test data is reported for lateral maneuvers of the HL-10 and M2/F3 lifting bodies, including the extraction of stability and control derivatives in the presence of wind gusts. All the problems encountered in this identification study are discussed. Several different methods (including a priori weighting, parameter fixing and constrained parameter values) for dealing with identifiability and uniqueness problems are introduced and the results given. The method for the design of optimal inputs for identifying the parameters of linear dynamic systems is also given. The criterion used for the optimization is the sensitivity of the system output to the unknown parameters. Several simple examples are first given and then the results of an extensive stability and control dervative identification simulation for a C-8 aircraft are detailed.

  8. Design for air-to-air refuelling operations; new passenger and tanker aircraft design for AAR scenarios

    NARCIS (Netherlands)

    Li, M.O.


    Air-to-air refuelling is a way to improve fuel efficiency of the overall transport system without waiting for the improvement of basic aviation technology. To take full advantage of such an operation, both passenger aircraft and tanker aircraft (which deliver required fuel to the passenger aircraft

  9. Efficient Multidisciplinary Analysis Approach for Conceptual Design of Aircraft with Large Shape Change (United States)

    Chwalowski, Pawel; Samareh, Jamshid A.; Horta, Lucas G.; Piatak, David J.; McGowan, Anna-Maria R.


    The conceptual and preliminary design processes for aircraft with large shape changes are generally difficult and time-consuming, and the processes are often customized for a specific shape change concept to streamline the vehicle design effort. Accordingly, several existing reports show excellent results of assessing a particular shape change concept or perturbations of a concept. The goal of the current effort was to develop a multidisciplinary analysis tool and process that would enable an aircraft designer to assess several very different morphing concepts early in the design phase and yet obtain second-order performance results so that design decisions can be made with better confidence. The approach uses an efficient parametric model formulation that allows automatic model generation for systems undergoing radical shape changes as a function of aerodynamic parameters, geometry parameters, and shape change parameters. In contrast to other more self-contained approaches, the approach utilizes off-the-shelf analysis modules to reduce development time and to make it accessible to many users. Because the analysis is loosely coupled, discipline modules like a multibody code can be easily swapped for other modules with similar capabilities. One of the advantages of this loosely coupled system is the ability to use the medium- to high-fidelity tools early in the design stages when the information can significantly influence and improve overall vehicle design. Data transfer among the analysis modules are based on an accurate and automated general purpose data transfer tool. In general, setup time for the integrated system presented in this paper is 2-4 days for simple shape change concepts and 1-2 weeks for more mechanically complicated concepts. Some of the key elements briefly described in the paper include parametric model development, aerodynamic database generation, multibody analysis, and the required software modules as well as examples for a telescoping wing

  10. H-infinity based integrated flight/propulsion control design for a STOVL aircraft in transition flight (United States)

    Garg, Sanjay; Mattern, Duane L.; Bright, Michelle; Ouzts, Peter


    This paper presents results from an application of H(infinity) control design methodology to a centralized integrated flight/propulsion control (IFPC) system design for a supersonic STOVL fighter aircraft in transition flight. The overall design methodology consists of a centralized IFPC design with controller partitioning. Design and evaluation vehicle models are summarized, and insight is provided into formulating the H(infinity) control problem such that it reflects the IFPC design objective. The H(infinity) controller is shown to provide decoupled command tracking for the design model. The controller order could be significantly reduced by modal residualization of the fast controller modes without any deterioration in performance.

  11. Bifurcation analysis and stability design for aircraft longitudinal motion with high angle of attack

    Directory of Open Access Journals (Sweden)

    Xin Qi


    Full Text Available Bifurcation analysis and stability design for aircraft longitudinal motion are investigated when the nonlinearity in flight dynamics takes place severely at high angle of attack regime. To predict the special nonlinear flight phenomena, bifurcation theory and continuation method are employed to systematically analyze the nonlinear motions. With the refinement of the flight dynamics for F-8 Crusader longitudinal motion, a framework is derived to identify the stationary bifurcation and dynamic bifurcation for high-dimensional system. Case study shows that the F-8 longitudinal motion undergoes saddle node bifurcation, Hopf bifurcation, Zero-Hopf bifurcation and branch point bifurcation under certain conditions. Moreover, the Hopf bifurcation renders series of multiple frequency pitch oscillation phenomena, which deteriorate the flight control stability severely. To relieve the adverse effects of these phenomena, a stabilization control based on gain scheduling and polynomial fitting for F-8 longitudinal motion is presented to enlarge the flight envelope. Simulation results validate the effectiveness of the proposed scheme.

  12. Design of PID Controllers of Anti-aircraft Artillery Servo System with Multiple Performance Specifications

    Institute of Scientific and Technical Information of China (English)

    LI Yin-ya; SHENG An-dong; WANG Yuan-gang


    A novel design method for determining the proportional-integral-derivative(PID) controller gains of an anti-aircraft artillery servo system with multiple performance specifications based on a particle swarm optimization (PSO) algorithm is proposed. First, a performance criterion evolution function combined with the system maximum displacement settling time, rise time, overshoot, steady state error, constant velocity tracking error and sine wave tracking error is defined. Second, the optimization problem of PID controller parameters and the searching procedure of PSO algorithm are constructed. Finally, the optimal or near optimal PID controller parameters are fast and easily obtained by solving the above optimization problem on the given controller parameter space following the PSO searching procedure. The simulation results show the effectiveness of the proposed controllers.

  13. A KBE-enabled design framework for cost/weight optimization study of aircraft composite structures (United States)

    Wang, H.; La Rocca, G.; van Tooren, M. J. L.


    Traditionally, minimum weight is the objective when optimizing airframe structures. This optimization, however, does not consider the manufacturing cost which actually determines the profit of the airframe manufacturer. To this purpose, a design framework has been developed able to perform cost/weight multi-objective optimization of an aircraft component, including large topology variations of the structural configuration. The key element of the proposed framework is a dedicated knowledge based engineering (KBE) application, called multi-model generator, which enables modelling very different product configurations and variants and extract all data required to feed the weight and cost estimation modules, in a fully automated fashion. The weight estimation method developed in this research work uses Finite Element Analysis to calculate the internal stresses of the structural elements and an analytical composite plate sizing method to determine their minimum required thicknesses. The manufacturing cost estimation module was developed on the basis of a cost model available in literature. The capability of the framework was successfully demonstrated by designing and optimizing the composite structure of a business jet rudder. The study case indicates the design framework is able to find the Pareto optimal set for minimum structural weight and manufacturing costin a very quick way. Based on the Pareto set, the rudder manufacturer is in conditions to conduct both internal trade-off studies between minimum weight and minimum cost solutions, as well as to offer the OEM a full set of optimized options to choose, rather than one feasible design.

  14. An Interactive Method of Characteristics Java Applet to Design and Analyze Supersonic Aircraft Nozzles (United States)

    Benson, Thomas J.


    The Method of Characteristics (MOC) is a classic technique for designing supersonic nozzles. An interactive computer program using MOC has been developed to allow engineers to design and analyze supersonic nozzle flow fields. The program calculates the internal flow for many classic designs, such as a supersonic wind tunnel nozzle, an ideal 2D or axisymmetric nozzle, or a variety of plug nozzles. The program also calculates the plume flow produced by the nozzle and the external flow leading to the nozzle exit. The program can be used to assess the interactions between the internal, external and plume flows. By proper design and operation of the nozzle, it may be possible to lessen the strength of the sonic boom produced at the rear of supersonic aircraft. The program can also calculate non-ideal nozzles, such as simple cone flows, to determine flow divergence and nonuniformities at the exit, and its effect on the plume shape. The computer program is written in Java and is provided as free-ware from the NASA Glenn central software server.

  15. Integrated autopilot/autothrottle for the NASA TSRV B-737 aircraft: Design and verification by nonlinear simulation (United States)

    Bruce, Kevin R.


    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.

  16. An Integrated Knowledge Based Engineering Mechatronics Modeling Approach to Support the Design of Unstable and Unmanned Aircraft

    NARCIS (Netherlands)

    Tian, F.N.


    The commercial transport aircraft industry is currently developing new “more electric aircraft” (MEA) designs in which various conventional mechanical, hydraulic and pneumatic power systems are replaced with electrically-based power systems. Their objective is to improve the overall flight performan

  17. Euler Technology Assessment program for preliminary aircraft design employing SPLITFLOW code with Cartesian unstructured grid method (United States)

    Finley, Dennis B.


    This report documents results from the Euler Technology Assessment program. The objective was to evaluate the efficacy of Euler computational fluid dynamics (CFD) codes for use in preliminary aircraft design. Both the accuracy of the predictions and the rapidity of calculations were to be assessed. This portion of the study was conducted by Lockheed Fort Worth Company, using a recently developed in-house Cartesian-grid code called SPLITFLOW. The Cartesian grid technique offers several advantages for this study, including ease of volume grid generation and reduced number of cells compared to other grid schemes. SPLITFLOW also includes grid adaptation of the volume grid during the solution convergence to resolve high-gradient flow regions. This proved beneficial in resolving the large vortical structures in the flow for several configurations examined in the present study. The SPLITFLOW code predictions of the configuration forces and moments are shown to be adequate for preliminary design analysis, including predictions of sideslip effects and the effects of geometry variations at low and high angles of attack. The time required to generate the results from initial surface definition is on the order of several hours, including grid generation, which is compatible with the needs of the design environment.

  18. Aircraft wing structural design optimization based on automated finite element modelling and ground structure approach (United States)

    Yang, Weizhu; Yue, Zhufeng; Li, Lei; Wang, Peiyan


    An optimization procedure combining an automated finite element modelling (AFEM) technique with a ground structure approach (GSA) is proposed for structural layout and sizing design of aircraft wings. The AFEM technique, based on CATIA VBA scripting and PCL programming, is used to generate models automatically considering the arrangement of inner systems. GSA is used for local structural topology optimization. The design procedure is applied to a high-aspect-ratio wing. The arrangement of the integral fuel tank, landing gear and control surfaces is considered. For the landing gear region, a non-conventional initial structural layout is adopted. The positions of components, the number of ribs and local topology in the wing box and landing gear region are optimized to obtain a minimum structural weight. Constraints include tank volume, strength, buckling and aeroelastic parameters. The results show that the combined approach leads to a greater weight saving, i.e. 26.5%, compared with three additional optimizations based on individual design approaches.

  19. A design and analysis approach for drag reduction on aircraft with adaptive lifting surfaces (United States)

    Cusher, Aaron Anthony

    Adaptive lifting surfaces, which can be tailored for different flight conditions, have been shown to be beneficial for drag reduction when compared with conventional non-adaptive surfaces. Applying multiple trailing-edge flaps along the wing span allows for the redistribution of lift to suit different flight conditions. The current approach uses the trailing-edge flap distribution to reduce both induced- and profile- components of drag with a trim constraint. Induced drag is reduced by optimally redistributing the lift between the lifting surfaces and along the span of each surface. Profile drag is reduced through the use of natural laminar flow airfoils, which maintain distinct low-drag-ranges (drag buckets) surrounding design lift values. The low-drag-ranges can be extended to include off-design values through small flap deflections, similar to cruise flaps. Trim is constrained for a given static margin by considering longitudinal pitching moment contributions from changes in airfoil section due to individual flap deflections, and from the redistribution of fore-and-aft lift due to combination of flap deflections. The approach uses the concept of basic and additional lift to linearlize the problem, which allows for standard constrained-minimization theory to be employed for determining optimal flap-angle solutions. The resulting expressions for optimal flap-angle solutions are presented as simple matrix equations. This work presents a design and analysis approach which is used to produce flap-angle solutions that independently reduce induced, profile, and total drag. Total drag is defined to be the sum of the induced- and profile-components of drag. The general drag reduction approach is adapted for each specific situation to develop specific drag reduction schemes that are applied to single- and multiple-surface configurations. Successful results show that, for the application of the induced drag reduction schemes on a tailless aircraft, near-elliptical lift

  20. YF-12 Lockalloy ventral fin program, volume 1. [design analysis, fabrication, and manufacturing of aircraft structures using aluminum and beryllium alloys for the lockheed YF-12 aircraft (United States)

    Duba, R. J.; Haramis, A. C.; Marks, R. F.; Payne, L.; Sessing, R. C.


    Results are presented of the YF-12 Lockalloy Ventral Fin Program which was carried out by Lockheed Aircraft Corporation - Advanced Development Projects for the joint NASA/USAF YF-12 Project. The primary purpose of the program was to redesign and fabricate the ventral fin of the YF-12 research airplane (to reduce flutter) using Lockalloy, and alloy of beryllium and aluminum, as a major structural material. A secondary purpose, was to make a material characterization study (thermodynamic properties, corrosion; fatigue tests, mechanical properties) of Lockalloy to validate the design of the ventral fin and expand the existing data base on this material. All significant information pertinent to the design and fabrication of the ventral fin is covered. Emphasis throughout is given to Lockalloy fabrication and machining techniques and attendant personnel safety precautions. Costs are also examined. Photographs of tested alloy specimens are shown along with the test equipment used.

  1. Design of the blisk of an aircraft turbojet engine and verification of its resonance free operation

    Directory of Open Access Journals (Sweden)

    Chromek L.


    Full Text Available Integral turbine wheels belong to one of the most stressed parts of jet aircraft engines. In addition to high rotational speeds and temperatures, they are also subjected to dynamic forces from a non-uniform pressure field in the flow path. Dynamic forces even at a relatively small amplitude can cause failure by fatigue, which leads to fracture of blades and crash of the machine. These adverse conditions, called resonance, should be avoided already in the design stage when a suitable choice of stator vanes and the number of blades can move the critical speed of the blisk beyond the operating speed or at least reduce their influence. In the case of a small jet engine produced by the První brněnská strojírna (PBS Velká Bíteš, the operating speed is of nearly half of the entire speed range of the machine. This makes the design of a proposed turbine wheel very complicated. A higher harmonic order of aerodynamic excitation is almost always present, its influence was therefore tested experimentally by vibration tests in the test station PBS Velká Bíteš.

  2. Improved Reliability-Based Optimization with Support Vector Machines and Its Application in Aircraft Wing Design

    Directory of Open Access Journals (Sweden)

    Yu Wang


    Full Text Available A new reliability-based design optimization (RBDO method based on support vector machines (SVM and the Most Probable Point (MPP is proposed in this work. SVM is used to create a surrogate model of the limit-state function at the MPP with the gradient information in the reliability analysis. This guarantees that the surrogate model not only passes through the MPP but also is tangent to the limit-state function at the MPP. Then, importance sampling (IS is used to calculate the probability of failure based on the surrogate model. This treatment significantly improves the accuracy of reliability analysis. For RBDO, the Sequential Optimization and Reliability Assessment (SORA is employed as well, which decouples deterministic optimization from the reliability analysis. The improved SVM-based reliability analysis is used to amend the error from linear approximation for limit-state function in SORA. A mathematical example and a simplified aircraft wing design demonstrate that the improved SVM-based reliability analysis is more accurate than FORM and needs less training points than the Monte Carlo simulation and that the proposed optimization strategy is efficient.

  3. System of systems design: Evaluating aircraft in a fleet context using reliability and non-deterministic approaches (United States)

    Frommer, Joshua B.

    This work develops and implements a solution framework that allows for an integrated solution to a resource allocation system-of-systems problem associated with designing vehicles for integration into an existing fleet to extend that fleet's capability while improving efficiency. Typically, aircraft design focuses on using a specific design mission while a fleet perspective would provide a broader capability. Aspects of design for both the vehicles and missions may be, for simplicity, deterministic in nature or, in a model that reflects actual conditions, uncertain. Toward this end, the set of tasks or goals for the to-be-planned system-of-systems will be modeled more accurately with non-deterministic values, and the designed platforms will be evaluated using reliability analysis. The reliability, defined as the probability of a platform or set of platforms to complete possible missions, will contribute to the fitness of the overall system. The framework includes building surrogate models for metrics such as capability and cost, and includes the ideas of reliability in the overall system-level design space. The concurrent design and allocation system-of-systems problem is a multi-objective mixed integer nonlinear programming (MINLP) problem. This study considered two system-of-systems problems that seek to simultaneously design new aircraft and allocate these aircraft into a fleet to provide a desired capability. The Coast Guard's Integrated Deepwater System program inspired the first problem, which consists of a suite of search-and-find missions for aircraft based on descriptions from the National Search and Rescue Manual. The second represents suppression of enemy air defense operations similar to those carried out by the U.S. Air Force, proposed as part of the Department of Defense Network Centric Warfare structure, and depicted in MILSTD-3013. The two problems seem similar, with long surveillance segments, but because of the complex nature of aircraft design

  4. 飞机舱门密封设计研究%Study on Design of the Aircraft Hatch Seal

    Institute of Scientific and Technical Information of China (English)



    舱门密封设计是飞机密封舱设计的重要组成部分,密封舱性能的好坏关系着飞机的飞行安全,因而舱门密封设计需要得到足够重视.舱门密封性能的影响因素很多,本文对影响结构密封性能的主要因素进行分析讨论,给出结构密封性能验证思路.%Design of the aircraft hatch seal is one of the most important parts of aircraft sealed cabin. The property of the aircraft hatch seal is relative to the airplane safety, so the design should be paid enough attention. There are many factors that affect the property of the aircraft hatch seal. In this study, the main effecting factors on structural sealing property are analyzed and discussed, and a testable method for the structural sealing property is presented.

  5. Design of an aircraft landing system using dual-frequency GNSS (United States)

    Konno, Hiroyuki

    There is a strong demand for new all-weather navigation aids to support aircraft precision approach and landing. The Federal Aviation Administration's Local Area Augmentation System (LAAS) is one such navigation aid that uses the Global Positioning System (GPS) to estimate aircraft location. LAAS is required to provide very high levels of accuracy, integrity, continuity, and availability, and the integrity requirement of one undetected navigation failure in a billion approaches has been a critical challenge in the design of this system. Tremendous efforts have developed methods to guarantee integrity for various potential anomalies that might threaten LAAS-aided landing. Currently, almost all these risks are mitigated by existing methods. One issue that remains is the risk due to ionosphere anomalies. This dissertation introduces novel integrity algorithms for ionosphere anomalies that take advantage of GPS modernization---undergoing changes in the GPS system that enhance civil user capabilities. This modernization includes adding new GPS civil signals, and these signals make possible multiple-frequency techniques. This research focuses on two types of dual-frequency carrier-smoothing methods---Divergence-Free Smoothing and Ionosphere-Free Smoothing---and develops integrity algorithms for ionosphere anomalies using these methods. Simulations show that the first algorithm, using Ionosphere-Free Smoothing, can achieve 96% to 99.9% availability at best over a broad region of the Conterminous United States (CONUS). This level of availability is unacceptably low for practical use. However, a benefit is that the resulting availability is not a function of the ionosphere condition. The second algorithm, based on Divergence-Free Smoothing, is shown by simulations to achieve more than 99.9% availability over more than 70% of CONUS under nominal ionosphere conditions. However, it has the potential to completely lose availability under severe ionosphere conditions. Taking

  6. Sensitivity Analysis for Safety Design Verification of General Aviation Reciprocating Aircraft Engine

    Institute of Scientific and Technical Information of China (English)

    CAO Jiaokun; DING Shuiting


    This paper presents an application of global sensitivity analysis for system safety analysis of reciprocating aircraft engine.Compared with local sensitivity analysis results,global sensitivity analysis could provide more information on parameter interactions,which are significant in complex system safety analysis.First,a deterministic aviation reciprocating engine thermodynamics model is developed and parameters of interest are defined as random variables.Then,samples are generated by Monte Carlo method for the parameters used in engine model on the basis of definition of factor distribution.Eventually,results from engine model are generated and importance indices are calculated.Based on the analysis results,design is improved to satisfy the airworthiness requirements.The results reveal that by using global sensitivity analysis,the parameters could be ranked with respect to their importance,including first order indices and total sensitivity indices.By reducing the uncertainty of parameters and adjusting the range of inputs,safety criteria would be satisfied.

  7. Bifurcation analysis and stability design for aircraft longitudinal motion with high angle of attack

    Institute of Scientific and Technical Information of China (English)

    Xin Qi; Shi Zhongke


    Bifurcation analysis and stability design for aircraft longitudinal motion are investigated when the nonlinearity in flight dynamics takes place severely at high angle of attack regime. To pre-dict the special nonlinear flight phenomena, bifurcation theory and continuation method are employed to systematically analyze the nonlinear motions. With the refinement of the flight dynam-ics for F-8 Crusader longitudinal motion, a framework is derived to identify the stationary bifurca-tion and dynamic bifurcation for high-dimensional system. Case study shows that the F-8 longitudinal motion undergoes saddle node bifurcation, Hopf bifurcation, Zero-Hopf bifurcation and branch point bifurcation under certain conditions. Moreover, the Hopf bifurcation renders ser-ies of multiple frequency pitch oscillation phenomena, which deteriorate the flight control stability severely. To relieve the adverse effects of these phenomena, a stabilization control based on gain scheduling and polynomial fitting for F-8 longitudinal motion is presented to enlarge the flight envelope. Simulation results validate the effectiveness of the proposed scheme.

  8. Active Flow Control with Adaptive Design Techniques for Improved Aircraft Safety Project (United States)

    National Aeronautics and Space Administration — The increased aircraft safety potential of active flow control using synthetic jets - specifically, using synthetic jets on the leading edge of the wing to delay...

  9. Design, cost, and advanced technology applications for a military trainer aircraft (United States)

    Hill, G. C.; Harper, M.


    The potential impact is examined of advanced aerodynamic and propulsive technologies in terms of operating and acquisition costs on conceptual mission and performance requirements for a future undergraduate jet pilot trainer aircraft.

  10. NASA Electric Aircraft Test Bed (NEAT) Development Plan - Design, Fabrication, Installation (United States)

    Dyson, Rodger W.


    As large airline companies compete to reduce emissions, fuel, noise, and maintenance costs, it is expected that more of their aircraft systems will shift from using turbofan propulsion, pneumatic bleed power, and hydraulic actuation, to instead using electrical motor propulsion, generator power, and electrical actuation. This requires new flight-weight and flight-efficient powertrain components, fault tolerant power management, and electromagnetic interference mitigation technologies. Moreover, initial studies indicate some combination of ambient and cryogenic thermal management and relatively high bus voltages when compared to state of practice will be required to achieve a net system benefit. Developing all these powertrain technologies within a realistic aircraft architectural geometry and under realistic operational conditions requires a unique electric aircraft testbed. This report will summarize existing testbed capabilities located in the U.S. and details the development of a unique complementary testbed that industry and government can utilize to further mature electric aircraft technologies.

  11. D/B/F 98: Final Report Of the AIAA Student Aircraft Design, Build & Fly Competition (United States)


    December with the intention of molding a composite center section and attaching various wing panels, such as wings with winglets or anhedral, to solve...integrity needed to fulfill the mission. Initially, the use of composite materials was investigated for use in the fabrication of the aircraft, but...material currently being removed from many commercial aircraft. (Newer airline floorboards use a Kevlar/Nomex composite sandwich, with a much higher

  12. Linear regulator design for stochastic systems by a multiple time scales method. [with application to F-8 aircraft longitudinal control (United States)

    Teneketzis, D.; Sandell, N. R., Jr.


    This paper develops a hierarchically-structured, suboptimal controller for a linear stochastic system composed of fast and slow subsystems. It is proved that the controller is optimal in the limit as the separation of time scales of the subsystems becomes infinite. The methodology is illustrated by design of a controller to suppress the phugoid and short period modes of the longitudinal dynamics of the F-8 aircraft.

  13. Evaluation of V/STOL research aircraft design. [landing approaches, propulsion/control, piloted moving base simulator (United States)

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


    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.

  14. U.S. aerospace industry opinion of the effect of computer-aided prediction-design technology on future wind-tunnel test requirements for aircraft development programs (United States)

    Treon, S. L.


    A survey of the U.S. aerospace industry in late 1977 suggests that there will be an increasing use of computer-aided prediction-design technology (CPD Tech) in the aircraft development process but that, overall, only a modest reduction in wind-tunnel test requirements from the current level is expected in the period through 1995. Opinions were received from key spokesmen in 23 of the 26 solicited major companies or corporate divisions involved in the design and manufacture of nonrotary wing aircraft. Development programs for nine types of aircraft related to test phases and wind-tunnel size and speed range were considered.

  15. 民用飞机FPGA设计研究%Preliminary Research of FPGA Design in Civil Aircraft

    Institute of Scientific and Technical Information of China (English)



    This paper studies the FPGA design in the civil aircraft,including the FPGA development life cycle,design and verification process,as well as the consideration of single-event upset preventing and the consideration of fully testable in critical system.%研究了民用飞机中FPGA的设计,主要包括FPGA设计的研制生命周期、设计与验证过程,以及在关键系统中FPGA设计的单粒子翻转效应及可测试性考虑。

  16. Integrated Design of a Long-Haul Commercial Aircraft Optimized for Formation Flying

    NARCIS (Netherlands)

    Dijkers, H.P.A.; Van Nunen, R.; Bos, D.A.; Gutleb, T.L.M.; Herinckx, L.E.; Radfar, H.; Van Rompuy, E.; Sayin, S.E.; De Wit, J.; Beelaerts van Blokland, W.W.A.


    The airline industry is under continuous pressure to reduce emissions and costs. This paper investigates the feasibility for commercial airlines to use formation flight to reduce emissions and fuel burn. To fly in formation, an aircraft needs to benefit from the wake vortices of the preceding aircra

  17. Measurements of total odd nitrogen (NOy aboard MOZAIC in-service aircraft: instrument design, operation and performance

    Directory of Open Access Journals (Sweden)

    D. Raak


    Full Text Available A small system for the unattended measurement of total odd nitrogen (NOy, i.e., the sum of NO and its atmospheric oxidation products aboard civil in-service aircraft in the framework of MOZAIC is described. The instrument employs the detection of NO by its chemiluminescence with O3 in combination with catalytic conversion of the other NOy compounds to NO at 300°C on a gold surface in the presence of H2. The instrument has a sensitivity of 0.4–7 cps/ppt and is designed for unattended operation during 1–2 service cycles of the aircraft (400–800 flight hours. The total weight is 50 kg, including calibration system, compressed gases, mounting, and safety measures. The layout and inlet configuration are governed by requirements due to the certification for passenger aircraft. Laboratory tests are described regarding the conversion efficiency for NO2 and HNO3 (both >98%. Interference by HCN and NH3 is 100% and <1%, respectively. The time response (90% time of the instrument is <1 s for NO2 and 150 s for HNO3, the latter being caused by memory effects in the 80 cm long inlet line.

  18. Design of a small personal air monitor and its application in aircraft. (United States)

    van Netten, Chris


    A small air sampling system using standard air filter sampling technology has been used to monitor the air in aircraft. The device is a small ABS constructed cylinder 5 cm in diameter and 9 cm tall and can be operated by non technical individuals at an instant notice. It is completely self contained with a 4 AAA cell power supply, DC motor, a centrifugal fan, and accommodates standard 37 mm filters and backup pads. The monitor is totally enclosed and pre assembled in the laboratory. A 45 degrees twist of the cap switches on the motor and simultaneously opens up the intake ports and exhaust ports allowing air to pass through the filter. A reverse 45 degrees twist of the cap switches off the motor and closes all intake and exhaust ports, completely enclosing the filter. The whole monitor is returned to the laboratory by standard mail for analysis and reassembly for future use. The sampler has been tested for electromagnetic interference and has been approved for use in aircraft during all phases of flight. A set of samples taken by a BAe-146-300 crew member during two flights in the same aircraft and analyzed by GC-MS, indicated exposure to tricresyl phosphate (TCP) levels ranging from 31 to 83 nanograms/m(3) (detection limit <4.5 nanograms/m(3)). The latter elevated level was associated with the use of the auxiliary power unit (APU) in the aircraft. It was concluded that the air sampler was capable of monitoring air concentrations of TCP isomers in aircraft above 4.5 nanogram/m(3).

  19. Effective L/D: A Theoretical Approach to the Measurement of Aero-Structural Efficiency in Aircraft Design (United States)

    Guynn, Mark D.


    There are many trade-offs in aircraft design that ultimately impact the overall performance and characteristics of the final design. One well recognized and well understood trade-off is that of wing weight and aerodynamic efficiency. Higher aerodynamic efficiency can be obtained by increasing wing span, usually at the expense of higher wing weight. The proper balance of these two competing factors depends on the objectives of the design. For example, aerodynamic efficiency is preeminent for sailplanes and long slender wings result. Although the wing weight-drag trade is universally recognized, aerodynamic efficiency and structural efficiency are not usually considered in combination. This paper discusses the concept of "aero-structural efficiency," which combines weight and drag characteristics. A metric to quantify aero-structural efficiency, termed effective L/D, is then derived and tested with various scenarios. Effective L/D is found to be a practical and robust means to simultaneously characterize aerodynamic and structural efficiency in the context of aircraft design. The primary value of the effective L/D metric is as a means to better communicate the combined system level impacts of drag and structural weight.

  20. Development of a Finite State Machine for a Small Unmanned Aircraft System Using Experimental Design (United States)


    SUAS) to autonomously track a moving ground vehicle. One drawback of the most common open source SUAS autopilot software, APM:Plane, is the... common significant factor to both models. Using the optimum airspeed settings resulted in improving aircraft endurance by approximately 30 percent under...stopping rule, checking the resulting model against the Akaike information criterion (AIC) and Mallows ’ Cp. The 24-run NCD experiment, a ground

  1. Designing an Interactive Local and Global Decision Support System for Aircraft Carrier Deck Scheduling (United States)


    Deck Scheduling Jason C. Ryana, M. L. Cummingsb, Nick Royc, Ashis Banerjeed Massachusetts Institute of Technology, Cambridge, MA, 02139 and Axel...the human satisficing, where only a small portion of the overall problem is solved. This perspective considers the individual aircraft as the point ...leak, a certain point in the future corresponds to the predicted complete loss of fuel. To signify this “ point of no return” to the operator, a

  2. Design and Performance Evaluation of Residual Generators for the FDI of an Aircraft

    Institute of Scientific and Technical Information of China (English)

    Marcello Bonfè; Paolo Castaldi; Walter Geri; Silvio Simani


    In this work, several procedures for the fault detection and isolation (FDI) on general aviation aircraft sensors are presented.In order to provide a comprehensive wide-spectrum treatment, both linear and nonlinear, mode~based and data-driven methodologies are considered. The main contributions of the paper are related to the development of both FDI polynomial method (PM) and FDI scheme based on the nonLinear geometric approach (NLGA). As to the PM, the obtained results highlight a good trade-off between solution complexity and resulting performances. Moreover, the proposed PM is especially useful when robust solutions are required for minimising the effects of modelling errors and noise, while maximising fault sensitivity. As to the NLGA, the proposed work is the first development and robust application of the NLGA to an aircraft model in flight conditions characterised by tight-coupled longitudinal and lateral dynamics. In order to verify the robustness of the residual generators related to the previous FDI techniques,the simulation results adopt a typical aircraft reference trajectory embedding several steady-state flight conditions, such as straight flight phases and coordinated turns. Moreover, the simulations are performed in the presence of both measurement and modelling errors. Finally, extensive simulations are used for assessing the overall capabilities of the developed FDI schemes and a comparison with neural networks (NN) and unknown input Kalman filter (UIKF) diagnosis methods is performed.

  3. Geometry Control System for Exploratory Shape Optimization Applied to High-Fidelity Aerodynamic Design of Unconventional Aircraft (United States)

    Gagnon, Hugo

    This thesis represents a step forward to bring geometry parameterization and control on par with the disciplinary analyses involved in shape optimization, particularly high-fidelity aerodynamic shape optimization. Central to the proposed methodology is the non-uniform rational B-spline, used here to develop a new geometry generator and geometry control system applicable to the aerodynamic design of both conventional and unconventional aircraft. The geometry generator adopts a component-based approach, where any number of predefined but modifiable (parametric) wing, fuselage, junction, etc., components can be arbitrarily assembled to generate the outer mold line of aircraft geometry. A unique Python-based user interface incorporating an interactive OpenGL windowing system is proposed. Together, these tools allow for the generation of high-quality, C2 continuous (or higher), and customized aircraft geometry with fast turnaround. The geometry control system tightly integrates shape parameterization with volume mesh movement using a two-level free-form deformation approach. The framework is augmented with axial curves, which are shown to be flexible and efficient at parameterizing wing systems of arbitrary topology. A key aspect of this methodology is that very large shape deformations can be achieved with only a few, intuitive control parameters. Shape deformation consumes a few tenths of a second on a single processor and surface sensitivities are machine accurate. The geometry control system is implemented within an existing aerodynamic optimizer comprising a flow solver for the Euler equations and a sequential quadratic programming optimizer. Gradients are evaluated exactly with discrete-adjoint variables. The algorithm is first validated by recovering an elliptical lift distribution on a rectangular wing, and then demonstrated through the exploratory shape optimization of a three-pronged feathered winglet leading to a span efficiency of 1.22 under a height

  4. H-infinity based integrated flight-propulsion control design for a STOVL aircraft in transition flight (United States)

    Garg, Sanjay; Mattern, Duane L.; Bright, Michelle M.; Ouzts, Peter J.


    Results are presented from an application of H-infinity control design methodology to a centralized integrated flight/propulsion control (IFPC) system design for a supersonic Short Take-Off and Vertical Landing (STOVL) fighter aircraft in transition flight. The overall design methodology consists of a centralized IFPC controller design with controller partitioning. Only the feedback controller design portion of the methodology is addressed. Design and evaluation vehicle models are summarized, and insight is provided into formulating the H-infinity control problem such that it reflects the IFPC design objectives. The H-infinity controller is shown to provide decoupled command tracking for the design model. The controller order could be significantly reduced by modal residualization of the fast controller modes without any deterioration in performance. A discussion is presented of the areas in which the controller performance needs to be improved, and ways in which these improvements can be achieved within the framework of an H-infinity based linear control design.

  5. Research on the Cockpit Design Characteristics for Commercial Aircraft%商用飞机驾驶舱造型设计特征研究

    Institute of Scientific and Technical Information of China (English)

    刘岗; 刘春荣


    This paper introduces the history and current situation of cockpit modeling design from Commercial Air-craft Corporation of China and other nations. First of all,a wide research was taken including an investigation of 5 different aircrafts and a collection of different types of aircraft cockpit pictures. Based on these, the design logic of different aircraft manufacturers was concluded. Sixty six cockpits from 12 aircraft companies are used as the cus-tomer research and cluster analysis and 10 typical cockpits are chosen from them. After that, the cockpit design characteristics and differences from main aircraft manufacturers are analyzed. The research provides a good refer-ence for new aircraft cockpit design.%介绍了国内外商用飞机驾驶舱设计的历史及现状,在分析多类飞机驾驶舱造型设计图片资料的基础上,探讨主要飞机制造商驾驶舱造型设计的特征。依据驾驶舱造型的相似性,对国际上12家商用飞机制造商的66款机型的驾驶舱进行聚类分析和多维尺度分析,挑选出10款有代表性的驾驶舱。在提取代表性驾驶舱造型特征线后,分析主要飞机制造商的驾驶舱造型设计特点及差异,为新型飞机驾驶舱造型设计提供参考。

  6. Solar Powered Aircraft, Photovoltaic Array/Battery System Tabletop Demonstration: Design and Operation Manual (United States)

    Colozza, Anthony J.; Scheiman, David A.; Bailey, Sheila (Technical Monitor)


    A system was constructed to demonstrate the power system operation of a solar powered aircraft. The system consists of a photovoltaic (PV) array, a charge controller, a battery, an electric motor and propeller. The system collects energy from the PV array and either utilizes this energy to operate an electric motor or stores it in a rechargeable battery for future use. The system has a control panel which displays the output of the array and battery as well as the total current going to the electric motor. The control panel also has a means for adjusting the output to the motor to control its speed. The entire system is regulated around 12 VDC.

  7. Design of a powered elevator control system. [powered elevator system for modified C-8A aircraft for STOL operation (United States)

    Glende, W. L. B.


    The design, fabrication and flight testing of a powered elevator system for the Augmentor Wing Jet STOL Research Aircraft (AWJSRA or Mod C-8A) are discussed. The system replaces a manual spring tab elevator control system that was unsatisfactory in the STOL flight regime. Pitch control in the AWJSRA is by means of a single elevator control surface. The elevator is used for both maneuver and trim control as the stabilizer is fixed. A fully powered, irreversible flight control system powered by dual hydraulic sources was designed. The existing control columns and single mechanical cable system of the AWJSRA have been retained as has been the basic elevator surface, except that the elevator spring tab is modified into a geared balance tab. The control surface is directly actuated by a dual tandem moving body actuator. Control signals are transmitted from the elevator aft quadrant to the actuator by a linkage system that includes a limited authority series servo actuator.

  8. Army-NASA aircrew/aircraft integration program (A3I) software detailed design document, phase 3 (United States)

    Banda, Carolyn; Chiu, Alex; Helms, Gretchen; Hsieh, Tehming; Lui, Andrew; Murray, Jerry; Shankar, Renuka


    The capabilities and design approach of the MIDAS (Man-machine Integration Design and Analysis System) computer-aided engineering (CAE) workstation under development by the Army-NASA Aircrew/Aircraft Integration Program is detailed. This workstation uses graphic, symbolic, and numeric prototyping tools and human performance models as part of an integrated design/analysis environment for crewstation human engineering. Developed incrementally, the requirements and design for Phase 3 (Dec. 1987 to Jun. 1989) are described. Software tools/models developed or significantly modified during this phase included: an interactive 3-D graphic cockpit design editor; multiple-perspective graphic views to observe simulation scenarios; symbolic methods to model the mission decomposition, equipment functions, pilot tasking and loading, as well as control the simulation; a 3-D dynamic anthropometric model; an intermachine communications package; and a training assessment component. These components were successfully used during Phase 3 to demonstrate the complex interactions and human engineering findings involved with a proposed cockpit communications design change in a simulated AH-64A Apache helicopter/mission that maps to empirical data from a similar study and AH-1 Cobra flight test.

  9. Cable Tensiometer for Aircraft (United States)

    Nunnelee, Mark (Inventor)


    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.

  10. Testing and Analysis of a Composite Non-Cylindrical Aircraft Fuselage Structure. Part 1; Ultimate Design Loads (United States)

    Przekop, Adam; Jegley, Dawn C.; Lovejoy, Andrew E.; Rouse, Marshall; Wu, Hsi-Yung T.


    The Environmentally Responsible Aviation Project aimed to develop aircraft technologies enabling significant fuel burn and community noise reductions. Small incremental changes to the conventional metallic alloy-based 'tube and wing' configuration were not sufficient to achieve the desired metrics. One airframe concept identified by the project as having the potential to dramatically improve aircraft performance was a composite-based hybrid wing body configuration. Such a concept, however, presented inherent challenges stemming from, among other factors, the necessity to transfer wing loads through the entire center fuselage section which accommodates a pressurized cabin confined by flat or nearly flat panels. This paper discusses finite element analysis and testing of a large-scale hybrid wing body center section structure developed and constructed to demonstrate that the Pultruded Rod Stitched Efficient Unitized Structure concept can meet these challenging demands of the next generation airframes. Part I of the paper considers the five most critical load conditions, which are internal pressure only and positive and negative g-loads with and without internal pressure. Analysis results are compared with measurements acquired during testing. Performance of the test article is found to be closely aligned with predictions and, consequently, able to support the hybrid wing body design loads in pristine and barely visible impact damage conditions.

  11. Design of Digital Autopilot for Lateral Motion Control of an Aircraft Based on l1-Optimization Approach

    Directory of Open Access Journals (Sweden)

    Leonid S. Zhiteckii


    Full Text Available The optimal digital autopilot needed to control of the roll for an aircraft in the presence of an arbitrary unmeasured disturbances is addressed in this paper. Such autopilot has to achieve a desired lateral motion control of this aircraft via minimizing the upper bound on the absolute value of the difference between the given and true roll angles. It is ensured by means of the two digital controllers. The inner controller is designed as the discrete-time PI controller in order to stabilize a given roll rate. This variable is formed by the external P controller. The necessary and sufficient conditions under which the two-circuit feedback discrete-time control system will be stable are derived. To optimize this control system, the controller parameters are derived utilizing the so-called l1-optimization approach advanced in modern control theory. A numerical example demonstrating the l1-optimization technique and results of some simulation experiments are presented to illustrate the performance of the l1-optimal controller. The robustness properties of this controller are established

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

    Energy Technology Data Exchange (ETDEWEB)

    Keidel, B.


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

  13. Matching design for payload and range of civil aircraft family%民用飞机系列商载航程匹配设计

    Institute of Scientific and Technical Information of China (English)

    蒙文巩; 马东立; 崔飞


    There has been a pattern transform from single model to family with multiple models for the civil aircraft-developing concept. According to the strategies of modularization and generality, the aircraft family design method was developed. The design principle of the main parameters and the economic description method for the aircraft family were presented. Then the matching design model for payload and range of the aircraft family was established. The impact of the matching relationship of the payload and the range acting on the economy of the aircraft family was analyzed, too. With application of Pareto multi-objective genetic algorithm, the matching design for payload and range of a civil aircraft family was accomplished. The parameter comparison of different design schemes was carried out,and the results are satisfactory.%民用飞机产品开发的模式已从“单型飞机”的概念向“飞机系列”概念转化.根据模块化和通用性的策略,发展了飞机系列化设计方法,给出了飞机系列主要参数的设计原则和飞机系列经济性的描述方法,建立了飞机系列商载航程匹配设计模型.分析了商载和航程的匹配关系对飞机系列经济性的影响,利用Pareto多目标遗传算法,完成了某一民用飞机系列商载和航程的匹配设计,对不同设计方案的参数进行了比较分析,取得了较好的设计结果.

  14. Design of Ultra-High-Power-Density Machine Optimized for Future Aircraft (United States)

    Choi, Benjamin B.


    The NASA Glenn Research Center's Structural Mechanics and Dynamics Branch is developing a compact, nonpolluting, bearingless electric machine with electric power supplied by fuel cells for future "more-electric" aircraft with specific power in the projected range of 50 hp/lb, whereas conventional electric machines generate usually 0.2 hp/lb. The use of such electric drives for propulsive fans or propellers depends on the successful development of ultra-high-power-density machines. One possible candidate for such ultra-high-power-density machines, a round-rotor synchronous machine with an engineering current density as high as 20,000 A/sq cm, was selected to investigate how much torque and power can be produced.

  15. Design of a Parallel Robot with a Large Workspace for the Functional Evaluation of Aircraft Dynamics beyond the Nominal Flight Envelope

    Directory of Open Access Journals (Sweden)

    Umar Asif


    Full Text Available This paper summarizes the development of a robotic system for the analysis of aircraft dynamics within and beyond the nominal flight envelope. The paper proposes the development of a parallel robot and its motion cueing algorithm to attain a reasonable workspace with adequate motion capabilities to facilitate the testing of aircraft stall and fault manoeuvrability scenarios. The proposed design combines two parallel mechanisms and aims to provide six degrees of freedom motion with a much larger motion envelope than the conventional hexapods in order to realize the manoeuvrability matching of aircraft dynamics near and beyond the upset flight envelopes. Finally the paper draws a comparative evaluation of motion capabilities between the proposed motion platform and a conventional hexapod based on Stewart configuration in order to emphasize the significance of the design proposed herein.

  16. SIFT - Design and analysis of a fault-tolerant computer for aircraft control. [Software Implemented Fault Tolerant systems (United States)

    Wensley, J. H.; Lamport, L.; Goldberg, J.; Green, M. W.; Levitt, K. N.; Melliar-Smith, P. M.; Shostak, R. E.; Weinstock, C. B.


    SIFT (Software Implemented Fault Tolerance) is an ultrareliable computer for critical aircraft control applications that achieves fault tolerance by the replication of tasks among processing units. The main processing units are off-the-shelf minicomputers, with standard microcomputers serving as the interface to the I/O system. Fault isolation is achieved by using a specially designed redundant bus system to interconnect the processing units. Error detection and analysis and system reconfiguration are performed by software. Iterative tasks are redundantly executed, and the results of each iteration are voted upon before being used. Thus, any single failure in a processing unit or bus can be tolerated with triplication of tasks, and subsequent failures can be tolerated after reconfiguration. Independent execution by separate processors means that the processors need only be loosely synchronized, and a novel fault-tolerant synchronization method is described.

  17. 飞机电刹车驱动器设计与研究%Design and Research of Aircraft Electric Braking Drive

    Institute of Scientific and Technical Information of China (English)

    谢世杰; 林辉; 戴志勇


    以飞机全电刹车为研究背景,介绍了飞机电刹车系统的组成.设计了以飞机直流电为驱动电源、无刷直流电动机作动器为控制对象的飞机电刹车驱动器.借助MATLAB,对电刹车驱动器进行仿真.仿真结果和实验结果表明,刹车驱动器设计合理,性能优良.%The components of aircraft electric braking system was described. The electric braking drive was designed with the DC power of aircraft as drive power and the brushless DC motor actuator as contrd object. The electric braking drive was simulated by MATLAB. The electric performance of aircraft electric braking drive was proven by simulation results and experimental results.

  18. Modified Linear Theory Aircraft Design Tools and Sonic Boom Minimization Strategy Applied to Signature Freezing via F-function Lobe Balancing (United States)

    Jung, Timothy Paul

    Commercial supersonic travel has strong business potential; however, in order for the Federal Aviation Administration to lift its ban on supersonic flight overland, designers must reduce aircraft sonic boom strength to an acceptable level. An efficient methodology and associated tools for designing aircraft for minimized sonic booms are presented. The computer-based preliminary design tool, RapidF, based on modified linear theory, enables quick assessment of an aircraft's sonic boom with run times less than 30 seconds on a desktop computer. A unique feature of RapidF is that it tracks where on the aircraft each segment of the of the sonic boom came from, enabling precise modifications, speeding the design process. Sonic booms from RapidF are compared to flight test data, showing that it is capability of predicting a sonic boom duration, overpressure, and interior shock locations. After the preliminary design is complete, scaled flight tests should be conducted to validate the low boom design. When conducting such tests, it is insufficient to just scale the length; thus, equations to scale the weight and propagation distance are derived. Using RapidF, a conceptual supersonic business jet design is presented that uses F-function lobe balancing to create a frozen sonic boom using lifting surfaces. The leading shock is reduced from 1.4 to 0.83 psf, and the trailing shock from 1.2 to 0.87 psf, 41% and 28% reductions respectfully. By changing the incidence angle of the surfaces, different sonic boom shapes can be created, and allowing the lobes to be re-balanced for new flight conditions. Computational fluid dynamics is conducted to validate the sonic boom predictions. Off-design analysis is presented that varies weight, altitude, Mach number, and propagation angle, demonstrating that lobe-balance is robust. Finally, the Perceived Level of Loudness metric is analyzed, resulting in a modified design that incorporates other boom minimization techniques to further reduce

  19. Anti-corrosion Design and Control of Aircraft Radar Cover%飞机雷达罩防腐蚀设计和控制

    Institute of Scientific and Technical Information of China (English)

    徐京祥; 吉选


    Aircraft radar cover as part of the aircraft structure, it should meet outside the erosion of a variety of environments, and its structure should not appear corrosion phenomena to ensure flight safety. The paper analyzes the material of aircraft radar cover and the common types of corrosion of structure according to the specific structure form and composition of aircraft radar cover, explores the corrosion mechanism of various types, and proposes the corrosion control design method of aircraft radar cover by combining with the protection and control measures of different materials and typical structure, to provide certain reference value for the structure design of aircraft radar cover.%飞机雷达罩作为飞机结构的一部分,应该满足外界各种环境侵蚀,结构上不应该出现腐蚀现象,以确保飞行安全,本文主要根据雷达罩具体结构形式和结构组成,分析了飞机雷达罩材料和结构上常见的腐蚀类型,通过对各种类型的腐蚀机理进行分析,结合不同材料和典型结构的防护和控制措施,提出飞机雷达罩腐蚀控制设计方法,对飞机雷达罩的结构设计提供一定的参考意义。

  20. Development of a Methodology to Support Design of Complex Aircraft Wings

    NARCIS (Netherlands)

    Cooper, C.A.


    The design of complex systems in today’s aerospace domain requires a balance between the ever-increasing complexity of the supporting technology and the drive to develop those systems in a compressed timeframe. The performance knowledge of a preliminary design must shift backwards in the lifecycle i

  1. Methodology of Computer-Aided Design of Variable Guide Vanes of Aircraft Engines (United States)

    Falaleev, Sergei V.; Melentjev, Vladimir S.; Gvozdev, Alexander S.


    The paper presents a methodology which helps to avoid a great amount of costly experimental research. This methodology includes thermo-gas dynamic design of an engine and its mounts, the profiling of compressor flow path and cascade design of guide vanes. Employing a method elaborated by Howell, we provide a theoretical solution to the task of…

  2. Essentials of aircraft armaments

    CERN Document Server

    Kaushik, Mrinal


    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. .

  3. Design-of-experiments to Reduce Life-cycle Costs in Combat Aircraft Inlets (United States)

    Anderson, Bernhard H.; Baust, Henry D.; Agrell, Johan


    It is the purpose of this study to demonstrate the viability and economy of Design- of-Experiments (DOE), to arrive at micro-secondary flow control installation designs that achieve optimal inlet performance for different mission strategies. These statistical design concepts were used to investigate the properties of "low unit strength" micro-effector installation. "Low unit strength" micro-effectors are micro-vanes, set a very low angle-of incidence, with very long chord lengths. They are designed to influence the neat wall inlet flow over an extended streamwise distance. In this study, however, the long chord lengths were replicated by a series of short chord length effectors arranged in series over multiple bands of effectors. In order to properly evaluate the performance differences between the single band extended chord length installation designs and the segmented multiband short chord length designs, both sets of installations must be optimal. Critical to achieving optimal micro-secondary flow control installation designs is the understanding of the factor interactions that occur between the multiple bands of micro-scale vane effectors. These factor interactions are best understood and brought together in an optimal manner through a structured DOE process, or more specifically Response Surface Methods (RSM).

  4. Design and Optimization of a Composite Canard Control Surface of an Advanced Fighter Aircraft under Static Loading

    Directory of Open Access Journals (Sweden)

    Shrivastava Sachin


    Full Text Available The minimization of weight and maximization of payload is an ever challenging design procedure for air vehicles. The present study has been carried out with an objective to redesign control surface of an advanced all-metallic fighter aircraft. In this study, the structure made up of high strength aluminum, titanium and ferrous alloys has been attempted to replace by carbon fiber composite (CFC skin, ribs and stiffeners. This study presents an approach towards development of a methodology for optimization of first-ply failure index (FI in unidirectional fibrous laminates using Genetic-Algorithms (GA under quasi-static loading. The GAs, by the application of its operators like reproduction, cross-over, mutation and elitist strategy, optimize the ply-orientations in laminates so as to have minimum FI of Tsai-Wu first-ply failure criterion. The GA optimization procedure has been implemented in MATLAB and interfaced with commercial software ABAQUS using python scripting. FI calculations have been carried out in ABAQUS with user material subroutine (UMAT. The GA's application gave reasonably well-optimized ply-orientations combination at a faster convergence rate. However, the final optimized sequence of ply-orientations is obtained by tweaking the sequences given by GA's based on industrial practices and experience, whenever needed. The present study of conversion of an all metallic structure to partial CFC structure has led to 12% of weight reduction. Therefore, the approach proposed here motivates designer to use CFC with a confidence.

  5. Euler Technology Assessment for Preliminary Aircraft Design: Compressibility Predictions by Employing the Cartesian Unstructured Grid SPLITFLOW Code (United States)

    Finley, Dennis B.; Karman, Steve L., Jr.


    The objective of the second phase of the Euler Technology Assessment program was to evaluate the ability of Euler computational fluid dynamics codes to predict compressible flow effects over a generic fighter wind tunnel model. This portion of the study was conducted by Lockheed Martin Tactical Aircraft Systems, using an in-house Cartesian-grid code called SPLITFLOW. The Cartesian grid technique offers several advantages, including ease of volume grid generation and reduced number of cells compared to other grid schemes. SPLITFLOW also includes grid adaption of the volume grid during the solution to resolve high-gradient regions. The SPLITFLOW code predictions of configuration forces and moments are shown to be adequate for preliminary design, including predictions of sideslip effects and the effects of geometry variations at low and high angles-of-attack. The transonic pressure prediction capabilities of SPLITFLOW are shown to be improved over subsonic comparisons. The time required to generate the results from initial surface data is on the order of several hours, including grid generation, which is compatible with the needs of the design environment.

  6. Active Flow Control with Adaptive Design Techniques for Improved Aircraft Safety Project (United States)

    National Aeronautics and Space Administration — The overall objective of this STTR effort is to evaluate and demonstrate the potential for well-designed, strategically-located synthetic jet actuators to provide...

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

  8. Innovative Structural and Material Concepts for Low-Weight Low-Drag Aircraft Design Project (United States)

    National Aeronautics and Space Administration — The overall objective of this multi-phase project is to explore, develop, integrate, and test several innovative structural design concepts and new material...

  9. Efficient algorithms for future aircraft design: Contributions to aerodynamic shape optimization (United States)

    Hicken, Jason Edward

    Advances in numerical optimization have raised the possibility that efficient and novel aircraft configurations may be "discovered" by an algorithm. To begin exploring this possibility, a fast and robust set of tools for aerodynamic shape optimization is developed. Parameterization and mesh-movement are integrated to accommodate large changes in the geometry. This integrated approach uses a coarse B-spline control grid to represent the geometry and move the computational mesh; consequently, the mesh-movement algorithm is two to three orders faster than a node-based linear elasticity approach, without compromising mesh quality. Aerodynamic analysis is performed using a flow solver for the Euler equations. The governing equations are discretized using summation-by-parts finite-difference operators and simultaneous approximation terms, which permit C0 mesh continuity at block interfaces. The discretization results in a set of nonlinear algebraic equations, which are solved using an efficient parallel Newton-Krylov-Schur strategy. A gradient-based optimization algorithm is adopted. The gradient is evaluated using adjoint variables for the flow and mesh equations in a sequential approach. The flow adjoint equations are solved using a novel variant of the Krylov solver GCROT. This variant of GCROT is flexible to take advantage of non-stationary preconditioners and is shown to outperform restarted flexible GMRES. The aerodynamic optimizer is applied to several studies of induced-drag minimization. An elliptical lift distribution is recovered by varying spanwise twist, thereby validating the algorithm. Planform optimization based on the Euler equations produces a nonelliptical lift distribution, in contrast with the predictions of lifting-line theory. A study of spanwise vertical shape optimization confirms that a winglet-up configuration is more efficient than a winglet-down configuration. A split-tip geometry is used to explore nonlinear wake-wing interactions: the

  10. Guidance Systems of Fighter Aircraft

    Directory of Open Access Journals (Sweden)

    K.N. Rajanikanth


    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.

  11. Guidance Systems of Fighter Aircraft


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


    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...

  12. Multimission Fuel-Burn Minimization in Aircraft Design: A Surrogate-Modeling Approach (United States)

    Liem, Rhea Patricia

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

  13. Experiment Design for Complex VTOL Aircraft with Distributed Propulsion and Tilt Wing (United States)

    Murphy, Patrick C.; Landman, Drew


    Selected experimental results from a wind tunnel study of a subscale VTOL concept with distributed propulsion and tilt lifting surfaces are presented. The vehicle complexity and automated test facility were ideal for use with a randomized designed experiment. Design of Experiments and Response Surface Methods were invoked to produce run efficient, statistically rigorous regression models with minimized prediction error. Static tests were conducted at the NASA Langley 12-Foot Low-Speed Tunnel to model all six aerodynamic coefficients over a large flight envelope. This work supports investigations at NASA Langley in developing advanced configurations, simulations, and advanced control systems.

  14. Tropospheric sampling with aircraft

    Energy Technology Data Exchange (ETDEWEB)

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


    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.

  15. Archetypical C2 Organization Design for Ever Increasing Technological Autonomy: An Unmanned Aircraft System Illustration (United States)


    diagnostic artificial intelligence (AI) applications in medicine (e.g., MYCIN; see Shortliffe & Buchanan 1975), electronics (e.g., SOPHIE; see Brown et...with Organization Design," The International C2 Journal 3:2 (2009), pp. 1-59. Brown, J.S., Burton, R.R., and de Kleer, J., “ Pedagogical , Natural

  16. Corrosion Protection and Design Improvement of an Aircraft%某型飞机腐蚀防护及设计改进

    Institute of Scientific and Technical Information of China (English)

    彭志军; 王学强; 叶彬


    Objective To study the corrosion problem of a certain aircraft, and to formulate structure corrosion repairing and anti-corrosion measures. Methods The corrosion reasons and the defects of the structure protection system were ob-tained after statistical analysis of aircraft corrosion classification and combing of the existing aircraft protection system. On the basis of aircraft serving area environment measurement, the aircraft ground parking environmental spectrum and the lo-cal environmental spectrum were developed. The design improvement measures for the structure protection system were taken, and the improvement effect of the design was verified by the accelerated corrosion test. Results Compared to the o-riginal state before improvement of the structure design, the calendar life of the anti-corrosion improvement structure was extend by 1. 6 to 5 times. Conclusion The aircraft was easy to subject to a variety of types of corrosion problems under the weak protection system. Good effect could only be achieved through systematic treatment of the problems in aircraft struc-ture corrosion.%目的:针对某型飞机的腐蚀问题开展研究,制定结构腐蚀修理和防腐改进措施。方法对外场飞机的腐蚀情况进行统计归类,对现有飞机防护体系进行梳理,分析结构腐蚀原因和防护体系的不足。在对飞机服役地区环境进行实测的基础上,编制飞机地面停放环境谱和飞机结构局部环境谱。研究制定结构防护体系设计改进措施,并通过加速腐蚀试验验证设计改进效果。结果与结构设计改进前的原始状态相比,防腐改进后的结构日历寿命提高1.6~5倍。结论飞机防护体系薄弱的情况下容易引发多种类型的腐蚀问题;系统地对飞机结构腐蚀问题进行治理,才能取得令人满意的效果。

  17. Transmission line design for a power distribution system at 20 kHz for aircraft (United States)

    Zelby, L. W.; Mathes, J. B.; Shawver, J. W.


    A low inductance, low characteristic impedance transmission line was designed for a 20 kHz power distribution system. Several different conductor configurations were considered: strip lines, interdigitated metal ribbons, and standard insulated wires in multiwire configurations (circular and rectangular cylindrical arrangements). The final design was a rectangular arrangement of multiple wires of the same gauge with alternating polarities from wire to wire. This offered the lowest inductance per unit length (on the order of several nanohenries/meter) and the lowest characteristic impedance (on the order of one Ohm). Standard multipin connectors with gold-plated elements were recommended with this transmission line, the junction boxes to be internally connected with flat metal ribbons for low inductance, and the line to be constructed in sections of suitable length. Computer programs for the calculation of inductance of multiwire lines and of capacitances of strip lines were developed.

  18. Process modelling and die design concepts for forming aircraft sheet parts (United States)

    Hatipoğlu, H. A.; Alkaş, C. O.


    This study is about typical sheet metal forming processes applied in aerospace industry including flexform, stretch form and stretch draw. Each process is modelled by using finite element method for optimization. Tensile, bulge, forming limit and friction tests of commonly used materials are conducted for defining the hardening curves, yield loci, anisotropic constants, forming limit curves and friction coefficients between die and sheet. Process specific loadings and boundary conditions are applied to each model. The models are then validated by smartly designed experiments that characterize the related forming processes. Lastly, several examples are given in which those models are used to predict the forming defects before physical forming and necessary die design and process parameter changes are applied accordingly for successful forming operations.

  19. Design Loads for Future Aircraft (Les Charges de Calcul Pour de Futurs Aeronefs) (United States)


    efforts during design, testing, and production shall be documented. VERIFICATION RATIONALE Documentation is required to provide an audit trail so that...acceptable level for start of production. The following incremental verifications should be accomplished prior to Physical Configuration Audit (PCA...Strength Load. PXX (1) Degree of Inspectability Typical Inspection Interval Magnification Factor, M(3) PFE In-Flight Evident One Flight(2) 100 PGE Ground

  20. The Design of Technological Instructions for an Assembling the Aircraft Engine

    Directory of Open Access Journals (Sweden)

    Martin Novák


    Full Text Available This article is about a design of new technological instructions for an aviation industry. The goal of the new technological instructions is to replace the old ones. The old instructions are less clear and less suitable for new workers. A change and an upgrade of the new instructions is shown on the technological instructions for disassembling of free turbine´s blades during general overhaul. The free turbine is from the M601 engine. The new instructions should be more efficient and enhanced general overhaul.

  1. Designing Serious Games for Safety Education: "Learn to Brace" versus Traditional Pictorials for Aircraft Passengers. (United States)

    Chittaro, Luca


    Serious games for safety education (SGSE) are a novel tool for preparing people to prevent and\\or handle risky situations. Although several SGSE have been developed, design and evaluation methods for SGSE need to be better grounded in and guided by safety-relevant psychological theories. In particular, this paper focuses on threat appeals and the assessment of variables, such as safety locus of control, that influence human behavior in real risky situations. It illustrates how we took into account such models in the design and evaluation of "Learn to Brace", a first-of-its-kind serious game that deals with a major problem in aviation safety, i.e. the scarce effectiveness of the safety cards used by airlines. The study considered a sample of 48 users: half of them received instructions about the brace position through the serious game, the other half through a traditional safety card pictorial. Results showed that the serious game was much more effective than the traditional instructions both in terms of learning and of changing safety-relevant perceptions, especially safety locus of control and recommendation perception.

  2. Predicting Visibility of Aircraft (United States)

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


    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

  3. Design of Prototype-Technology Evaluator and Research Aircraft (PTERA) Configuration for Loss of Control Flight Research Project (United States)

    National Aeronautics and Space Administration — The Area-I team has developed and fabricated the unmanned Prototype-Technology Evaluation and Research Aircraft or PTERA ("ptera" being Greek for wing, or...

  4. Aerodynamic design optimization of nacelle/pylon position on an aircraft

    Institute of Scientific and Technical Information of China (English)

    Li Jing; Gao Zhenghong; Huang Jiangtao; Zhao Ke


    The arbitrary space-shape free form deformation (FFD) method developed in this paper is based on non-uniform rational B-splines (NURBS) basis function and used for the integral parameterization of nacelle-pylon geometry.The multi-block structured grid deformation technique is established by Delaunay graph mapping method.The optimization objects of aerodynamic characteristics are evaluated by solving Navier-Stokes equations on the basis of multi-block structured grid.The advanced particle swarm optimization (PSO) is utilized as search algorithm,which combines the Kriging model as surrogate model during optimization.The optimization system is used for optimizing the nacelle location of DLR-F6 wing-body-pylon-nacelle.The results indicate that the aerodynamic interference between the parts is significantly reduced.The optimization design system established in this paper has extensive applications and engineering value.

  5. Design, analysis, and control of large transport aircraft utilizing engine thrust as a backup system for the primary flight controls (United States)

    Gerren, Donna S.


    A review of accidents that involved the loss of hydraulic flight control systems serves as an introduction to this project. In each of the accidents--involving transport aircraft such as the DC-10, the C-5A, the L-1011, and the Boeing 747--the flight crew attempted to control the aircraft by means of thrust control. Although these incidents had tragic endings, in the absence of control power due to primary control system failure, control power generated by selective application of engine thrust has proven to be a viable alternative. NASA Dryden has demonstrated the feasibility of controlling an aircraft during level flight, approach, and landing conditions using an augmented throttles-only control system. This system has been successfully flown in the flight test simulator for the B-720 passenger transport and the F-15 air superiority fighter and in actual flight tests for the F-15 aircraft. The Douglas Aircraft Company is developing a similar system for the MD-11 aircraft. The project's ultimate goal is to provide data for the development of thrust control systems for mega-transports (600+ passengers).

  6. Analyses of Aircraft Responses to Atmospheric Turbulence

    NARCIS (Netherlands)

    Van Staveren, W.H.J.J.


    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. 可伸缩折叠式四旋翼飞行器设计%Design for the Scalable Folding Quad Rotor Aircraft

    Institute of Scientific and Technical Information of China (English)

    李波陈; 王红州; 刘晓栋; 徐兴国; 李彦锐


    The optimization design for quad rotor aircraft is completed in this article for its structural shape is awkward to car-ry.Through analyzing the structure characteristics and flight principles, a quad rotor aircraft platform that could automatically retract and fold is designed, and its strength is then checked, and finally 3D modeling simulation and experimental tests are conducted.The result shows that design of the quad rotor aircraft successfully achieves automatic retractable and manual fold-ing, and meanwhile could save the carrying space, thus it gets good effects.%针对四旋翼飞行器的结构外形不便于随身携带的特点,进行了优化设计。通过分析四旋翼飞行器结构特点和飞行原理,设计出可自动伸缩、折叠的四旋翼飞行器平台,并进行强度校核,最后进行了三维仿真建模与模型制作和试验测试。结果表明设计的四旋翼无人飞行器实现了空中自动伸缩、着陆后手动折叠的功能,同时节省携带空间,达到了良好的效果。

  8. Results of correlations for transition location on a clean-up glove installed on an F-14 aircraft and design studies for a laminar glove for the X-29 aircraft accounting for spanwise pressure gradient (United States)

    Goradia, S. H.; Bobbitt, P. J.; Morgan, H. L.; Ferris, J. C.; Harvey, William D.


    Results of correlative and design studies for transition location, laminar and turbulent boundary-layer parameters, and wake drag for forward swept and aft swept wings are presented. These studies were performed with the use of an improved integral-type boundary-layer and transition-prediction methods. Theoretical predictions were compared with flight measurements at subsonic and transonic flow conditions for the variable aft swept wing F-14 aircraft for which experimental pressure distributions, transition locations, and turbulent boundary-layer velocity profiles were measured. Flight data were available at three spanwise stations for several values of sweep, freestream unit Reynolds number, Mach numbers, and lift coefficients. Theory/experiment correlations indicate excellent agreement for both transition location and turbulent boundary-layer parameters. The results of parametric studies performed during the design of a laminar glove for the forward swept wing X-29 aircraft are also presented. These studies include the effects of a spanwise pressure gradient on transition location and wake drag for several values of freestream Reynolds numbers at a freestream Mach number of 0.9.

  9. Weibull-Based Design Methodology for Rotating Structures in Aircraft Engines

    Directory of Open Access Journals (Sweden)

    Erwin V. Zaretsky


    Full Text Available The NASA Energy-Efficient Engine (E3-Engine is used as the basis of a Weibull-based life and reliability analysis. Each component's life, and thus the engine's life, is defined by high-cycle fatigue or low-cycle fatigue. Knowing the cumulative life distribution of each of the components making up the engine as represented by a Weibull slope is a prerequisite to predicting the life and reliability of the entire engine. As the engine's Weibull slope increases, the predicted life decreases. The predicted engine lives L5 (95% probability of survival of approximately 17,000 and 32,000 hr do correlate with current engine-maintenance practices without and with refurbishment, respectively. The individual high-pressure turbine (HPT blade lives necessary to obtain a blade system life L0.1 (99.9% probability of survival of 9000 hr for Weibull slopes of 3, 6, and 9 are 47,391; 20,652; and 15,658 hr, respectively. For a design life of the HPT disks having probable points of failure equal to or greater than 36,000 hr at a probability of survival of 99.9%, the predicted disk system life L0.1 can vary from 9408 to 24,911 hr.

  10. Euler technology assessment for preliminary aircraft design employing OVERFLOW code with multiblock structured-grid method (United States)

    Treiber, David A.; Muilenburg, Dennis A.


    The viability of applying a state-of-the-art Euler code to calculate the aerodynamic forces and moments through maximum lift coefficient for a generic sharp-edge configuration is assessed. The OVERFLOW code, a method employing overset (Chimera) grids, was used to conduct mesh refinement studies, a wind-tunnel wall sensitivity study, and a 22-run computational matrix of flow conditions, including sideslip runs and geometry variations. The subject configuration was a generic wing-body-tail geometry with chined forebody, swept wing leading-edge, and deflected part-span leading-edge flap. The analysis showed that the Euler method is adequate for capturing some of the non-linear aerodynamic effects resulting from leading-edge and forebody vortices produced at high angle-of-attack through C(sub Lmax). Computed forces and moments, as well as surface pressures, match well enough useful preliminary design information to be extracted. Vortex burst effects and vortex interactions with the configuration are also investigated.

  11. Aircraft electromagnetic compatibility (United States)

    Clarke, Clifton A.; Larsen, William E.


    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.

  12. Analyses of Aircraft Responses to Atmospheric Turbulence


    Van Staveren, W.H.J.J.


    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...

  13. Advanced aerodynamic design for commercial aircraft%民机空气动力设计先进技术

    Institute of Scientific and Technical Information of China (English)



    文章简要地介绍了两种民机空气动力先进设计技术的概念及其研究进展。一为层流流动主动控制技术。其核心措施是减弱流动的不稳定性,推迟转捩的发生,从而增大层流流动区域。目前混合层流流动控制方法发展比较充分,有望应用于未来民机的设计中。另一为新型非常规布局,包括翼身融合体、支撑机翼、吞吸机身边界层等新型气动布局,这些均有望大大提高未来民机的性能。%The concepts and the research on two kinds of advanced aerodynamic technolo-gy are briefly reviewed. One is laminar flow active control, which focuses on increasing the lami-nar flow region through decreasing flow instability and delaying the transition. A hybrid laminar flow control method has now been developed and probably will be used in future design. The other is a new type of aerodynamic shape, which can greatly increase the performance of commercial transport aircraft. Three new types of configuration——the blended wing body, strut-braced wing, and body boundary layer ingestion will be briefly described.

  14. Application of MBSE Method During Landing Gear System Design for Civil Aircraft%MBSE在民机起落架系统设计中的应用

    Institute of Scientific and Technical Information of China (English)

    汤超; 方俊伟; 谢陵; 张磊; 夏语冰


    This paper clearly introduces function analysis process and method of large-scale civil aircraft based on Raphsody, and its implementation in landing gear system design. Usecase, function flow, sequence and executable state machine of syetem are set up by model. toguide the requirement analysis, function analysis and architecture design of highly complex system in large-scale civil aircraft, and to explore practice of MBSE in highly complex system of civil aircraft.%详细介绍基于Raphsody的大型民机系统功能开发流程与方法,及其在民用飞机起落架系统设计中的应用。通过模型的方式对系统建立用例、功能流、时序关系和可用于执行验证的状态机来描述系统,指导大型民机复杂系统设计过程中的需求分析、功能分析和设计综合工作,探索MBSE方法在民机复杂系统设计中的指导作用。

  15. The Study of Large Civil Aircraft Flight Control System Design Philosophy%大型民用飞机飞控系统设计理念研究

    Institute of Scientific and Technical Information of China (English)



    Design philosophy shall be an idea which will be built before project starts to launch. As the flight control system’s top level input, it will directly affect the design of control handling device, system architecture, control law architecture and so on. Civil aircraft flight control system’s design philosophy was studied from the view of methodology. Lifecycle, philosophy characteristics and strategic essence were erected, the influence factors were analyzed importantly, architecture and evaluation method were set up, and the relative database between aircraft accidents and design philosophy were developed, provided aircraft manufacturers to define the flight control system’s design philosophy for the theoretical method direction and technical basis.%飞控系统设计理念是大型民用飞机飞控系统设计的顶层输入,直接影响着飞控操纵器件、系统架构、控制律架构等设计。该文从方法论角度探索和研究了民用飞机飞控系统设计理念,重点分析了设计理念影响因素,建立了设计理念体系结构,提出了设计理念评估方法,建立了民机事故与设计理念的关系数据库,为民机制造商确立自己的民用飞机飞控系统设计理念提供了理论方法指导和技术基础。

  16. Advanced Design Composite Aircraft (United States)


    tensile properties. The cost increase is minimal. The alloy 7471.-T76 has been selected to replace 7075, since it has higher toughness and virtually the...i. / fy/’AtJ’Jk fyfJPt’Mi RAY PPff LOHOtKON WfJEK LOHuneOAJ Wf-Ti AL AL/ \\ \\ I I ENälNl COMPT AULA sopezPLAinc yexwD JET FLAP hwP

  17. 某机载电子设备总体结构设计%Structure Design of Airborne Electronic Equipment for a Certain Aircraft

    Institute of Scientific and Technical Information of China (English)

    南雁; 郭建平; 张娅妮


    从结构设计角度出发,根据航空平台的工作模式和环境空间要求,针对某机载电子设备的标准化设计、热设计、电磁兼容性设计、防冲击、振动、"三防"设计等方面进行了论述.结合型号设计的工程经验,以航空电子设备结构设计的特点和原则为重点,对机载电子设备的结构设计进行了阐述,通过合理的布局设计和仿真计算来实现结构设计要求.介绍机载电子设备结构设计的经验,可供同行参考.%From the point of structure design,according to work and environment requisition for the aircraft flat ,described delailed such as the standardization, heat, EMC,impact and vibration prevention,three proofing designing for a certain aircraft. Focus on the characteristic and principle for aeronauticat electronic equipment,expatiate the structure design from Many- sided ,and guidance thc structure design by logical position and simulation with engineering experience. Pool the experience for structure design and offer the experience for craft brother discuss.

  18. Quantifying the impact of BOReal forest fires on Tropospheric oxidants over the Atlantic using Aircraft and Satellites (BORTAS experiment: design, execution and science overview

    Directory of Open Access Journals (Sweden)

    P. I. Palmer


    Full Text Available We describe the design and execution of the BORTAS (Quantifying the impact of BOReal forest fires on Tropospheric oxidants using Aircraft and Satellites experiment, which has the overarching objective of understanding the chemical aging of airmasses that contain the emission products from seasonal boreal wildfires and how these airmasses subsequently impact downwind atmospheric composition. The central focus of the experiment was a two-week deployment of the UK BAe-146-301 Atmospheric Research Aircraft (ARA over eastern Canada. The planned July 2010 deployment of the ARA was postponed by 12 months because of activities related to the dispersal of material emitted by the Eyjafjallajökull volcano. However, most other planned model and measurement activities, including ground-based measurements at the Dalhousie University Ground Station (DGS, enhanced ozonesonde launches, and measurements at the Pico Atmospheric Observatory in the Azores, went ahead and constituted phase A of the experiment. Phase B of BORTAS in July 2011 included the same measurements, but included the ARA, special satellite observations and a more comprehensive measurement suite at the DGS. The high-frequency aircraft data provided a comprehensive snapshot of the pyrogenic plumes from wildfires. The coordinated ground-based and sonde data provided detailed but spatially-limited information that put the aircraft data into context of the longer burning season. We coordinated aircraft vertical profiles and overpasses of the NASA Tropospheric Emission Spectrometer and the Canadian Atmospheric Chemistry Experiment. These space-borne data, while less precise than other data, helped to relate the two-week measurement campaign to larger geographical and longer temporal scales. We interpret these data using a range of chemistry models: from a near-explicit gas-phase chemical mechanism, which tests out understanding of the underlying chemical mechanism, to regional and global 3-D models

  19. Design of test system for aircraft power system based on Labwindows/CVI%基于Labwindows/CVI某型飞机电源检测系统设计

    Institute of Scientific and Technical Information of China (English)

    范雪扬; 高玉章; 宋伟健


    针对维修保障中需要对某型飞机电源系统进行快速检测这一需求,设计了一种基于Labwindows/CVI的飞机电源检测系统,用来实现对该系统相关电气参数的准确测量.实际应用表明,该系统具有运行稳定可靠、操作方便、维护简单的特点,检测结果准确可靠,能够满足该型飞机电源系统的维护保障需要.%Aim at the requirement of the fast test for the aircraft power system, the design of aircraft power test system based on Labwindows/CVI is introduced in this paper. The system can realize the exact test results for the electric parameters of the aircraft power system. The result shows that the system has good and reliable performance for measurement of parameters test, and can satisfy the requirement of the power system for maintenance support.

  20. 民用飞机设计驾驶舱操纵设备的评估%Evaluation on Flight Cockpit Control Equipments of Civil Aircraft Design

    Institute of Scientific and Technical Information of China (English)

    丰立东; 赵京洲; 田金强


    人机工效影响着飞行员操纵飞机的感受,因此在民用飞机设计过程中,对人机工效进行及早考虑是非常重要的。在民用飞机设计的各个阶段,都需要适时邀请具有一定资质的飞行员对驾驶舱的人机工效进行评估。对民用飞机设计中飞控驾驶舱飞行员评估方法进行介绍,对评估的要点进行总结分析,供相关工程设计人员参考。%Human factors affect the feeling of pilots operating airplanes. It is necessary to take human factors into account at the beginning of designing civil aircraft. During each phase of designing civil aircraft, it is necessary to invite qualified pilots to evaluate human factors in cockpit when needed. A method of pilot evaluation related with flight cockpit control system in designing civil airplane is introduced and some important issues are summarized and analyzed so as to refer to other relevant engineers and designers when necessary.

  1. Amphibious Aircraft (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. 民机结构设计中的系统工程问题%Systems Engineering for Commercial Aircraft Structural Design

    Institute of Scientific and Technical Information of China (English)



    Systems engineering has been widely applied into highly-integrated complex commercial aircraft development.As an important component,the aircraft structural design will receive innovation with systems engineering introduced.Systems engineering processes in commercial aircraft structural design include function analysis,requirements analysis,structural synthesis, structure production,structural integration,structural tests and so on.Structural requirements are built based on structural design levels and shall be validated and verified.Other systems engineering process include interface management,configuration management and technical risk management.%系统工程在高度集成的复杂民机产品的研制中已得到广泛应用。作为民机设计的重要组成部分,民机结构设计中如能引入系统工程过程和方法,必能有效促进民机结构设计工作的革新。民机结构设计的系统工程过程包括功能分析、需求分析、结构设计、零部件生产、部段和全机结构集成及试验试飞等过程。民机结构需求体系须按照结构设计层级进行制定,并依次进行需求确认和需求验证。民机结构设计相关的系统工程问题还包括接口管理、构型管理、技术风险管理等。

  3. Design of a Robot for Defect Inspection on Aircraft Skin%飞机蒙皮缺陷检查机器人系统设计

    Institute of Scientific and Technical Information of China (English)

    牛国臣; 胡丹丹; 王漫


    To inspect the aircraft skin defects automatically and make the inspection work effectively, a wall climbing robot was developed, which could move on aircraft skin and take nondestructive examination. A design scheme of a climbing robot was proposed , aiming at the non symmetrical aircraft skin with changed curvature, and key components were chosen. By analyzing security of the robot, structural parameters were determined. A control system in which motor control was integrated with pneumatic control was designed, and the robot prototype was manufactured. Experimental result shows that the work of the robot is stable and reliable. So the design is reasonable and feasible.%为实现飞机蒙皮缺陷的自动检查,使得飞机蒙皮检修工作有效进行,研究一种能在飞机表面爬行和进行无损检测的机器人.针对飞机蒙皮非对称变曲率的特点,提出了爬行机器人的总体设计方案,确定了其关键机构及元件,并从安全性角度进行了详细分析,确定了机器人结构参数.设计了电动及气动相结合的控制系统结构,并研制了机器人样机.实验结果表明:机器人工作稳定可靠,验证了设计方案的合理性及可行性.

  4. 面向飞行器设计领域的溯源实现%Aircraft Design Domain Oriented Provenance Realization

    Institute of Scientific and Technical Information of China (English)

    张雄; 谷建华


    Based on application oriented and customizable cross-domain service platform, we represent the data flow of aircraft design domain workflow, analyze the process information, establish the provenance data model of the specific domain, design the hbase/hadoop based distributed storage model, and finally give the provenance capture framework. By the post analyzing functionality of provenance sub-system, we can effectively assist scientist in solving problems confronted in the experiment and accelerate the the progress of aircraft design.%本文以面向应用可定制的跨域协同服务支撑平台为依托,描述面向飞行器设计领域的工作流的数据流,对流程历史信息进行分析提炼,建立特定领域的溯源数据模型,设计基于hadoop/hbase的分布式存储模型,给出溯源的捕获框架.通过溯源子系统提供的流程事后分析功能,可以有效协助设计人员分析流程中遇到的问题,加速飞行器设计进度.

  5. The Design and Use of a Temperature-Compensated Hot-Film Anemometer System for Boundary-Layer Flow Transition Detection on Supersonic Aircraft (United States)

    Chiles, Harry R.


    An airborne temperature-compensated hot-film anemometer system has been designed, fabricated, and used to obtain in-flight airfoil boundary-layer flow transition data by the NASA Ames-Dryden Flight Research Facility. Salient features of the anemometer include near constant sensitivity over the full flight envelope, installation without coaxial wiring, low-noise outputs, and self-contained signal conditioning with dynamic and steady-state outputs. The small size, low-power dissipation, and modular design make the anemometer suitable for use in modern high-performance research aircraft. Design of the temperature-compensated hot-film anemometer and its use for flow transition detection on a laminar flow flight research project are described. Also presented are data gathered in flight which is representative of the temperature-compensated hot-film anemometer operation at subsonic, transonic, and supersonic flight conditions.

  6. 大型水陆两栖飞机翼型优化设计%Optimum airfoil design on an heavy amphibious aircraft

    Institute of Scientific and Technical Information of China (English)

    秦何军; 曾友兵


    对大型水陆两栖飞机翼型进行了数值优化设计研究,通过以翼型设计升力系数下的阻力系数最小化为设计目标和以翼型低头力矩、最大升力系数、失速后升力系数下降率作为约束条件的大型水陆两栖飞机翼型优化设计,在满足翼型相对厚度、最大厚度位置、最大弯度、最大弯度位置符合相应设计范围的情况下,得到了综合性能较基本翼型提高的新翼型.该设计方法适用于大型水陆两栖飞机的翼型设计,是一种符合工程应用实际的数值优化设计方法.%The research discussed focused upon the optimal airfoil shape design of a heavy amphibious aircraft. A new airfoil with better general performance was attained through the optimal airfoil design, of which the objective was to reduce the drag coefficient on a given airfoil with constant lift coefficient. Restricted the pitch moment, the maximum lift, and the lift drop rate of stalling angle. Made the relative thick, the maximum camber, and the relative position of the maximum thick according with the design request. This design method is fit for the airfoil design on a heavy amphibious aircraft, and is a better optimal airfoil shape design which is suit for the engineering application.

  7. Army-NASA aircrew/aircraft integration program. Phase 5: A3I Man-Machine Integration Design and Analysis System (MIDAS) software concept document (United States)

    Banda, Carolyn; Bushnell, David; Chen, Scott; Chiu, Alex; Neukom, Christian; Nishimura, Sayuri; Prevost, Michael; Shankar, Renuka; Staveland, Lowell; Smith, Greg


    This is the Software Concept Document for the Man-machine Integration Design and Analysis System (MIDAS) being developed as part of Phase V of the Army-NASA Aircrew/Aircraft Integration (A3I) Progam. The approach taken in this program since its inception in 1984 is that of incremental development with clearly defined phases. Phase 1 began in 1984 and subsequent phases have progressed at approximately 10-16 month intervals. Each phase of development consists of planning, setting requirements, preliminary design, detailed design, implementation, testing, demonstration and documentation. Phase 5 began with an off-site planning meeting in November, 1990. It is expected that Phase 5 development will be complete and ready for demonstration to invited visitors from industry, government and academia in May, 1992. This document, produced during the preliminary design period of Phase 5, is intended to record the top level design concept for MIDAS as it is currently conceived. This document has two main objectives: (1) to inform interested readers of the goals of the MIDAS Phase 5 development period, and (2) to serve as the initial version of the MIDAS design document which will be continuously updated as the design evolves. Since this document is written fairly early in the design period, many design issues still remain unresolved. Some of the unresolved issues are mentioned later in this document in the sections on specific components. Readers are cautioned that this is not a final design document and that, as the design of MIDAS matures, some of the design ideas recorded in this document will change. The final design will be documented in a detailed design document published after the demonstrations.

  8. Aircraft Wiring Support Equipment Integration Laboratory (AWSEIL) (United States)

    Federal Laboratory Consortium — Purpose:The Aircraft Wiring Support Equipment Integration Laboratory (AWSEIL) provides a variety of research, design engineering and prototype fabrication services...

  9. Aircraft Wiring Support Equipment Integration Laboratory (AWSEIL) (United States)

    Federal Laboratory Consortium — Purpose: The Aircraft Wiring Support Equipment Integration Laboratory (AWSEIL) provides a variety of research, design engineering and prototype fabrication services...

  10. CAD System for Aircraft Structure Static Test Design%飞机结构静力试验 CAD 系统

    Institute of Scientific and Technical Information of China (English)

    侯同济; 张建锋; 滕申科


      飞机结构静力试验设计系统(Aircraft Structure Static Test Design System-ASSTDS)是用于全尺寸飞机结构静力试验设计的、图形交互式的计算机辅助设计(CAD)软件系统。本文介绍了基于面向对象技术完成的软件系统需求分析、功能分解和对象抽象,软件开发过程中建立的系统对象体系以及主要对象和它们之间的相互关系。飞机结构静力试验设计系统采用 VC++编程语言在 Windows 操作系统上开发完成的。%The ASSTDS system is a special graphical interactive CAD software for the aircraft structure static test design. The paper introduces the requesting analysis, function decomposing and object abstracting for the sofeware based on object-oriented technology and the object architecture in the software development. The main objects and their relationships are also described. ASSTDS is developed in the programming language VC++ on the Windows operation system.

  11. Design Method and Key Technologies of US Energy Optimized Aircraft%美国能量优化飞机设计方法与关键技术

    Institute of Scientific and Technical Information of China (English)



    With the enhanced functions, the modern combat aircrafts are facing increasingly serious problem of power and heat consumption, the INVENT plan and the EOA concept which USA intends to solve the problem are developed. For the plan, it’s background and development plan and the EOA’s main object are introduced. The MRIP which is an important aircraft system energy design method is analyzed through building the “tip-to-tail” model, and the key technologies of EOA design are elaborated.%随着功能的增强,现代作战飞机将面临严重的功率和热耗问题。美国为解决这这一问题开发了综合飞行器能量技术(INVENT)计划,提出了能量优化飞机(EOA)概念。针对INVENT计划,介绍了背景、发展规划及EOA的主要目标。通过建立“从头到尾”(tip-to-tail)模型,分析了飞机系统能量设计的重要方法-MRIP,阐述了EOA设计时的关键技术。

  12. 75 FR 50865 - Airworthiness Directives; Various Aircraft Equipped With Rotax Aircraft Engines 912 A Series Engines (United States)


    ... Equipped With Rotax Aircraft Engines 912 A Series Engines AGENCY: Federal Aviation Administration (FAA... 912 A series engine installed in various aircraft does not have an engine type certificate; instead, the engine is part of the aircraft type design. Comments We gave the public the opportunity...

  13. 75 FR 32315 - Airworthiness Directives; Various Aircraft Equipped With Rotax Aircraft Engines 912 A Series Engines (United States)


    ... Equipped With Rotax Aircraft Engines 912 A Series Engines AGENCY: Federal Aviation Administration (FAA... certificated in the United States. However, the Model 912 A series engine installed in various aircraft does not have an engine type certificate; instead, the engine is part of the aircraft type design. You...

  14. Aircraft cybernetics (United States)


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

  15. Quantifying the impact of BOReal forest fires on Tropospheric oxidants over the Atlantic using Aircraft and Satellites (BORTAS experiment: design, execution and science overview

    Directory of Open Access Journals (Sweden)

    P. I. Palmer


    Full Text Available We describe the design and execution of the BORTAS (Quantifying the impact of BOReal forest fires on Tropospheric oxidants over the Atlantic using Aircraft and Satellites experiment, which has the overarching objective of understanding the chemical aging of air masses that contain the emission products from seasonal boreal wildfires and how these air masses subsequently impact downwind atmospheric composition. The central focus of the experiment was a two-week deployment of the UK BAe-146-301 Atmospheric Research Aircraft (ARA over eastern Canada, based out of Halifax, Nova Scotia. Atmospheric ground-based and sonde measurements over Canada and the Azores associated with the planned July 2010 deployment of the ARA, which was postponed by 12 months due to UK-based flights related to the dispersal of material emitted by the Eyjafjallajökull volcano, went ahead and constituted phase A of the experiment. Phase B of BORTAS in July 2011 involved the same atmospheric measurements, but included the ARA, special satellite observations and a more comprehensive ground-based measurement suite. The high-frequency aircraft data provided a comprehensive chemical snapshot of pyrogenic plumes from wildfires, corresponding to photochemical (and physical ages ranging from 45 sr 10 days, largely by virtue of widespread fires over Northwestern Ontario. Airborne measurements reported a large number of emitted gases including semi-volatile species, some of which have not been been previously reported in pyrogenic plumes, with the corresponding emission ratios agreeing with previous work for common gases. Analysis of the NOy data shows evidence of net ozone production in pyrogenic plumes, controlled by aerosol abundance, which increases as a function of photochemical age. The coordinated ground-based and sonde data provided detailed but spatially limited information that put the aircraft data into context of the longer burning season in the boundary layer. Ground

  16. Quantifying the impact of BOReal forest fires on Tropospheric oxidants over the Atlantic using Aircraft and Satellites (BORTAS) experiment: design, execution and science overview (United States)

    Palmer, P. I.; Parrington, M.; Lee, J. D.; Lewis, A. C.; Rickard, A. R.; Bernath, P. F.; Duck, T. J.; Waugh, D. L.; Tarasick, D. W.; Andrews, S.; Aruffo, E.; Bailey, L. J.; Barrett, E.; Bauguitte, S. J.-B.; Curry, K. R.; Di Carlo, P.; Chisholm, L.; Dan, L.; Forster, G.; Franklin, J. E.; Gibson, M. D.; Griffin, D.; Helmig, D.; Hopkins, J. R.; Hopper, J. T.; Jenkin, M. E.; Kindred, D.; Kliever, J.; Le Breton, M.; Matthiesen, S.; Maurice, M.; Moller, S.; Moore, D. P.; Oram, D. E.; O'Shea, S. J.; Owen, R. C.; Pagniello, C. M. L. S.; Pawson, S.; Percival, C. J.; Pierce, J. R.; Punjabi, S.; Purvis, R. M.; Remedios, J. J.; Rotermund, K. M.; Sakamoto, K. M.; da Silva, A. M.; Strawbridge, K. B.; Strong, K.; Taylor, J.; Trigwell, R.; Tereszchuk, K. A.; Walker, K. A.; Weaver, D.; Whaley, C.; Young, J. C.


    We describe the design and execution of the BORTAS (Quantifying the impact of BOReal forest fires on Tropospheric oxidants over the Atlantic using Aircraft and Satellites) experiment, which has the overarching objective of understanding the chemical aging of air masses that contain the emission products from seasonal boreal wildfires and how these air masses subsequently impact downwind atmospheric composition. The central focus of the experiment was a two-week deployment of the UK BAe-146-301 Atmospheric Research Aircraft (ARA) over eastern Canada, based out of Halifax, Nova Scotia. Atmospheric ground-based and sonde measurements over Canada and the Azores associated with the planned July 2010 deployment of the ARA, which was postponed by 12 months due to UK-based flights related to the dispersal of material emitted by the Eyjafjallajökull volcano, went ahead and constituted phase A of the experiment. Phase B of BORTAS in July 2011 involved the same atmospheric measurements, but included the ARA, special satellite observations and a more comprehensive ground-based measurement suite. The high-frequency aircraft data provided a comprehensive chemical snapshot of pyrogenic plumes from wildfires, corresponding to photochemical (and physical) ages ranging from 45 sr 10 days, largely by virtue of widespread fires over Northwestern Ontario. Airborne measurements reported a large number of emitted gases including semi-volatile species, some of which have not been been previously reported in pyrogenic plumes, with the corresponding emission ratios agreeing with previous work for common gases. Analysis of the NOy data shows evidence of net ozone production in pyrogenic plumes, controlled by aerosol abundance, which increases as a function of photochemical age. The coordinated ground-based and sonde data provided detailed but spatially limited information that put the aircraft data into context of the longer burning season in the boundary layer. Ground-based measurements of

  17. Quantifying the Impact of BOReal Forest Fires on Tropospheric Oxidants Over the Atlantic Using Aircraft and Satellites (BORTAS) Experiment: Design, Execution, and Science Overview (United States)

    Palmer, Paul I.; Parrington, Mark; Lee, James D.; Lewis, Alistair C.; Richard, Andrew R.; Bernath, Peter F.; Pawson, Steven; daSilva, Arlindo M.; Duck, Thomas J.; Waugh, David L.; Tarasick, Daivd W.; Andrews, Stephen; Aruffo, Eleonora; Bailey, Loren J.; Barrett, Lucy; Bauguitte, Stephan J.-B.; Curry, Kevin R.; DiCarlo, Piero; Chisholm, Lucy; Dan, Lin; Forster, Grant; Franklin, Jonathan E.; Gibson, Mark D.; Griffin, Debora; Moore, David P.


    We describe the design and execution of the BORTAS (Quantifying the impact of BOReal forest fires on Tropospheric oxidants using Aircraft and Satellites) experiment, which has the overarching objective of understanding the chemical aging of airmasses that contain the emission products from seasonal boreal wildfires and how these airmasses subsequently impact downwind atmospheric composition. The central focus of the experiment was a two-week deployment of the UK BAe-146-301 Atmospheric Research Aircraft (ARA) over eastern Canada. The planned July 2010 deployment of the ARA was postponed by 12 months because of activities related to the dispersal of material emitted by the Eyjafjallaj¨okull volcano. However, most other planned model and measurement activities, including ground-based measurements at the Dalhousie University Ground Station (DGS), enhanced ozonesonde launches, and measurements at the Pico Atmospheric Observatory in the Azores, went ahead and constituted phase A of the experiment. Phase B of BORTAS in July 2011 included the same measurements, but included the ARA, special satellite observations and a more comprehensive measurement suite at the DGS. Integrating these data helped us to describe pyrogenic plumes from wildfires on a wide spectrum of temporal and spatial scales. We interpret these data using a range of chemistry models, from a near-explicit gas-phase chemical mechanism to regional and global models of atmospheric transport and lumped chemistry. We also present an overview of some of the new science that has originated from this project.

  18. French aircraft carrier design using virtual reality%虚拟现实技术在法国航母设计中的应用

    Institute of Scientific and Technical Information of China (English)



    A French virtual-reality simulation software named GASPAR is described.This software was developed in order to simulate different configurations of the French Navy' s future aircraft carrier and test their viability.Two supporting libraries upon which the software GASPAR is built is introduced,then the structure and use of the software follows.Finally,some results that the software has validated about the aircraft carrier design are given.%介绍法国开发的一款虚拟现实仿真软件GASPAR.该软件用于仿真法国海军未来航母的各种配置并测试它们的生存能力.首先介绍GASPAR软件的两大基础库,以及该软件的构成和用法,最后给出该软件在航母设计验证中的典型应用.

  19. 民用飞机融合式翼梢小翼优化设计%The optimization design of winglet for civial aircraft

    Institute of Scientific and Technical Information of China (English)

    翁晨涛; 夏露; 李丁


    Improving the performance of civil aircraft mainly depends on drag reduction.On the condition of cruise, the efficiency of reducing the whole plane's drag will be improved greatly if the induced drag of the wing can be reduced.In this paper, based on the civial aircraft pure wing, winglet is used to reduce the induced drag.Besides, the winglet's shape is optimized with the objective of reducing drag and the flowing mechanism is analyzed to make preparation for further study of winglet design.%民用飞机性能的提高将在很大程度上依赖于降低空气阻力.在巡航状态下,如果能减小机翼的诱导阻力,则全机的减阻效果将会得到很明显的提高.因此,本文以民用飞机机翼为设计平台,通过加装融合式翼梢小翼来减阻,并在设计了初始小翼的基础上,将减阻作为设计目标,对翼梢小翼的平面几何形状进行优化,并对结果进行了流动机理分析.

  20. A NASA study of the impact of technology on future multimission aircraft (United States)

    Samuels, Jeffrey J.


    A conceptual aircraft design study was recently completed which compared three supersonic multimission tactical aircraft. The aircraft were evaluated in two technology timeframes and were sized with consistent methods and technology assumptions so that the aircraft could be compared in operational utility or cost analysis trends. The three aircraft are a carrier-based Fighter/Attack aircraft, a land-based Multirole Fighter, and a Short Takeoff/Vertical Landing (STOVL) aircraft. This paper describes the design study ground rules used and the aircraft designed. The aircraft descriptions include weights, dimensions and layout, design mission and maneuver performance, and fallout mission performance. The effect of changing technology and mission requirements on the STOVL aircraft and the impact of aircraft navalization are discussed. Also discussed are the effects on the STOVL aircraft of both Thrust/Weight required in hover and design mission radius.

  1. 飞机复合材料结构的概率设计方法%Probabilistic Design Methodology for Composite Aircraft Structure

    Institute of Scientific and Technical Information of China (English)

    陈普会; 肖闪闪


    In current design methodologies for composite aircraft structures, design parameters are considered as deterministic variables while their random are ignored. In fact, many parameters affect aircraft structures safety, and some of them have obvious random features which can not be ignored. Therefore a probabilistic design methodology must be developed with the consideration of main random variables. However, probabilistic design methodologies have been gradually developed and used for composite structure design. Six popular probabilistic design methodologies are discussed in details and their benefits and potential problems are summarized. Finally, the issues to be adressed are recognized in the probabilistic design of composite structures, which provides some helpful suggestions for further study.%当前在军用和民用飞机复合材料结构设计方法中,主要设计变量是按确定量来处理的而忽略了它们的随机性,即确定性方法.实际上,飞机结构的安全性要受到很多因素的影响,其中一些主要影响因素具有明显的、不可忽视的随机特性.因此,更先进的设计思想是发展能综合考虑各种主要因素的随机性的结构设计方法,即结构概率分析与设计方法.概率设计方法已经逐渐成熟,并且开始用于复合材料结构设计.本文详细讨论了国外提出的6种主流的概率设计方法,总结了它们的分析流程以及优缺点.本文最后指出了复合材料结构概率设计研究中有待解决的问题,为进一步开展飞机复合材料结构的概率设计方法的研究提供了有益的建议.

  2. Introduction to civil aircraft optical fiber cable installation design requirements%浅谈民用飞机光缆安装设计要求

    Institute of Scientific and Technical Information of China (English)



    Optical fiber communication compared with the traditional electrical communication has many advantages in terms of signal transmission; Optical fiber communication technology also has been widely used in civil aircraft, in this paper, the optical fiber cable installation design requirements are introduced to ensure the optical fiber communication function work normally during installation without damage.%光纤通信和传统电气通信相比在信号传输方面有许多优势,光纤通信技术在民用飞机上也得到了越来越多的应用,对光缆的安装设计要求进行了介绍,确保光缆在安装敷设过程中不会受到破坏以及保证光纤通信正常。

  3. Aircraft Data Acquisition


    Elena BALMUS


    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...

  4. Design of repairing mould for minor trauma of Aircraft wing%飞机机翼微小创伤修复模具的设计

    Institute of Scientific and Technical Information of China (English)

    范文学; 李宗学; 李林喜; 王东辉


    An easy,economic and accurate micro-knocking repairing method that the micro trauma in aircraft wing crashed by the bird is quickly repaired by precise pad mould is put forward. The important step of method is to design the pad mould, so the repairing principle of the aircraft wing micro trauma is analyzed. Three repairing plans are proposed and their advantages and disadvantages are compared. The laminated wood was selected as material of pad mould,three-coordinate measuring instru-ment was used as a tool of data acquisition,and CNC milling and grinder were used as processing equipments,by which the pad mould design was achieved. The practical application proves that method is able to meet the repair requirements.%针对飞机机翼被鸟击后的快速修复提出了简便、经济、精确的精模衬垫微敲修复法,该方法的关键是衬模设计,为此分析了机翼微小创伤的修复原理,提出了三种修复方案,并对比其优缺点,最终以木质叠板为衬模材料,三坐标测量仪为数据获取工具,数控铣床及磨床为加工设备的理念完成机翼衬模的设计,并得到实际应用验证,其结果良好能够满足修复要求。

  5. Integration of a code for aeroelastic design of conventional and composite wings into ACSYNT, an aircraft synthesis program. [wing aeroelastic design (WADES) (United States)

    Mullen, J., Jr.


    A comparison of program estimates of wing weight, material distribution. structural loads and elastic deformations with actual Northrop F-5A/B data is presented. Correlation coefficients obtained using data from a number of existing aircraft were computed for use in vehicle synthesis to estimate wing weights. The modifications necessary to adapt the WADES code for use in the ACSYNT program are described. Basic program flow and overlay structure is outlined. An example of the convergence of the procedure in estimating wing weights during the synthesis of a vehicle to satisfy F-5 mission requirements is given. A description of inputs required for use of the WADES program is included.

  6. Sensitivity of Mission Energy Consumption to Turboelectric Distributed Propulsion Design Assumptions on the N3-X Hybrid Wing Body Aircraft (United States)

    Felder, James L.; Tong, Michael T.; Chu, Julio


    In a previous study by the authors it was shown that the N3-X, a 300 passenger hybrid wing body (HWB) aircraft with a turboelectric distributed propulsion (TeDP) system, was able to meet the NASA Subsonic Fixed Wing (SFW) project goal for N+3 generation aircraft of at least a 60% reduction in total energy consumption as compared to the best in class current generation aircraft. This previous study combined technology assumptions that represented the highest anticipated values that could be matured to technology readiness level (TRL) 4-6 by 2030. This paper presents the results of a sensitivity analysis of the total mission energy consumption to reductions in each key technology assumption. Of the parameters examined, the mission total energy consumption was most sensitive to changes to total pressure loss in the propulsor inlet. The baseline inlet internal pressure loss is assumed to be an optimistic 0.5%. An inlet pressure loss of 3% increases the total energy consumption 9%. However changes to reduce inlet pressure loss can result in additional distortion to the fan which can reduce fan efficiency or vice versa. It is very important that the inlet and fan be analyzed and optimized as a single unit. The turboshaft hot section is assumed to be made of ceramic matrix composite (CMC) with a 3000 F maximum material temperature. Reducing the maximum material temperature to 2700 F increases the mission energy consumption by only 1.5%. Thus achieving a 3000 F temperature in CMCs is important but not central to achieving the energy consumption objective of the N3-X/TeDP. A key parameter in the efficiency of superconducting motors and generators is the size of the superconducting filaments in the stator. The size of the superconducting filaments in the baseline model is assumed to be 10 microns. A 40 micron filament, which represents current technology, results in a 200% increase in AC losses in the motor and generator stators. This analysis shows that for a system with 40

  7. Fault Tolerance, Diagnostics, and Prognostics in Aircraft Flight (United States)

    National Aeronautics and Space Administration — Abstract In modern fighter aircraft with statically unstable airframe designs, the flight control system is considered flight critical, i.e. the aircraft will...

  8. Aircraft recognition and tracking device (United States)

    Filis, Dimitrios P.; Renios, Christos I.


    The technology of aircraft recognition and tracking has various applications in all areas of air navigation, be they civil or military, spanning from air traffic control and regulation at civilian airports to anti-aircraft weapon handling and guidance for military purposes.1, 18 The system presented in this thesis is an alternative implementation of identifying and tracking flying objects, which benefits from the optical spectrum by using an optical camera built into a servo motor (pan-tilt unit). More specifically, through the purpose-developed software, when a target (aircraft) enters the field of view of the camera18, it is both detected and identified.5, 22 Then the servo motor, being provided with data on target position and velocity, tracks the aircraft while it is in constant communication with the camera (Fig. 1). All the features are so designed as to operate under real time conditions.

  9. 微型四轴飞行器的设计与实现%Design and implementation of mini quad-rotors aircraft

    Institute of Scientific and Technical Information of China (English)

    薛鹏; 任鹏飞; 曹学儒; 马壮


    The quad-rotor mini rotorcraft is an under actuated system,which is powered by adjusting the speed of the motors. In order to discuss the problem of quad-rotor aircraft control,the preliminary design of the control system was proposed. The hardware of flight control system was designed based on single chip microcontroller STM32 and sensor MPU6050. The key points include driven cir-cuit,sensors and communication module. Based on PID control scheme,the software was fulfilled. As its core part,quaternion num-bers and Kalman filtering were adopted to obtain exact values of the attitude angles. Simulation and indoor tests results shown that the designed hardware system is reliable and can meet requirements. Some meaningful experiences to the design of quad-rotor aircraft are introduced.%四轴飞行器是通过调节电机转速来控制运动姿态的典型欠驱动系统,为研究飞行器的姿态控制问题,对飞行控制系统进行了初步设计。硬件部分以STM32单片机为主控芯片,采用MPU6050陀螺仪传感器完成飞行控制系统的选型设计,重点讨论了驱动电路、传感器和通信模块的选型设计。软件部分以PID控制为基础,重点介绍了姿态角检测过程中的四元数变换和卡尔曼滤波环节,这两个步骤保障了所得姿态角的准确性。仿真分析和室内测试显示,该硬件设计性能可靠,其姿态角控制达到了预期效果,对四轴飞行器的设计有借鉴意义。

  10. 基于事故/事件的民机人因防错设计关键因素研究%Research on key factors of human error proofing design for civil aircraft based on accidents/incidents

    Institute of Scientific and Technical Information of China (English)

    高扬; 王向章; 李晓旭


    Aiming at the influence of human error proofing design for civil aircraft on flight safety, 92 typical acci-dents cases by human factors were selected from the world civil aviation safety accidents/incidents database.The element incident analysis method was applied to conduct deep analysis, then the important design factors which need to be considered in the human error proofing design for civil aircraft was summarized, and the important design factor set was established.Based on the man-machine-environment model in systems engineering, and combined with the relevant standards for aircrafts design at home and abroad, an index system of important factors about hu-man error proofing design for civil aircraft was built.The FAHP method was used to calculate the weight of inde-xes, and 14 key factors of human error proofing design that influence the flight safety were determined.Finally, the general requirements of human error proofing design for civil aircraft were proposed against the key factors.It can provide reference for the human error proofing design for civil aircraft to better meet the requirements of initial air-worthiness.%针对民机人因防错设计对飞行安全的影响,从世界民航安全事故/事件数据库中筛选出92起典型的人为因素事故案例,采用基元事件分析法进行深度分析,提炼出民机人因防错设计需要考虑的重要设计因素,并建立重要设计因素集。基于系统工程学的“人机环”模型,结合国内外飞机设计相关标准,建立民机人因防错设计重要因素指标体系。运用模糊层次分析法对因素指标进行权重计算,确立影响飞行安全的14项人因防错设计关键因素,并针对这些关键因素提出民机人因防错设计通用要求,以期为民机人因防错设计满足初始适航要求提供参考。

  11. Static Aeroelasticity in Combat Aircraft. (United States)


    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

  12. Multidisciplinary Techniques and Novel Aircraft Control Systems (United States)

    Padula, Sharon L.; Rogers, James L.; Raney, David L.


    The Aircraft Morphing Program at NASA Langley Research Center explores opportunities to improve airframe designs with smart technologies. Two elements of this basic research program are multidisciplinary design optimization (MDO) and advanced flow control. This paper describes examples where MDO techniques such as sensitivity analysis, automatic differentiation, and genetic algorithms contribute to the design of novel control systems. In the test case, the design and use of distributed shape-change devices to provide low-rate maneuvering capability for a tailless aircraft is considered. The ability of MDO to add value to control system development is illustrated using results from several years of research funded by the Aircraft Morphing Program.

  13. 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


    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.

  14. Research on Flight Test Method for Evaluating Aircraft Cockpit Design%飞机座舱设计评估的试飞方法研究

    Institute of Scientific and Technical Information of China (English)



    飞行试验是评估飞机座舱设计最好的方法,飞行试验阶段选取的评估方法应能获得全面的、足够的信息和来自用户有价值的反馈。本文在分析国内外用于座舱评估的人机工程标准的基础上,总结了用于座舱设计评估的基本方法和评估内容,介绍了用于座舱评估的工作负荷评价方法。%Flight test is the best method for evaluating aircraft cockpit design.The evaluation method selected during the flight test should obtain comprehensive and adequate information and valuable feedback from user.On the basis of analyzing human engineering standards for cockpit evaluation,the basic method and evaluation content are summarized and the workload evaluation method for cockpit design is introduced.

  15. 飞机襟翼控制系统故障分析及改进设计%Fault Analysis and Improvement Design for Aircraft Flap Control System

    Institute of Scientific and Technical Information of China (English)

    张晓燕; 张巍


    针对某型飞机襟翼操纵开关操作不便,并且无法完全实现单电机收放襟翼的问题,重新布置了襟翼操纵开关位置,分析襟翼控制系统的故障,并进行了改进设计,实现了单套控制电路和电机收放襟翼的目的,提高了襟翼操纵系统的可靠性。设计改进得到了飞行试验的验证。%In view of the problems that the lfap control switch is operated inconveniently and a single electrical motor does not realize lfap retraction or extension in some aircrafts, this paper rearranges the layout of lfap control switch, analyses the foult and improves the design of the lfap control system ,realizes the object of retraction/extension the lfap though a single control circuit and motor,and improves the reliability of the lfap control system. Design improvement is veriifed by lfight test.

  16. Euler Technology Assessment for Preliminary Aircraft Design-Unstructured/Structured Grid NASTD Application for Aerodynamic Analysis of an Advanced Fighter/Tailless Configuration (United States)

    Michal, Todd R.


    This study supports the NASA Langley sponsored project aimed at determining the viability of using Euler technology for preliminary design use. The primary objective of this study was to assess the accuracy and efficiency of the Boeing, St. Louis unstructured grid flow field analysis system, consisting of the MACGS grid generation and NASTD flow solver codes. Euler solutions about the Aero Configuration/Weapons Fighter Technology (ACWFT) 1204 aircraft configuration were generated. Several variations of the geometry were investigated including a standard wing, cambered wing, deflected elevon, and deflected body flap. A wide range of flow conditions, most of which were in the non-linear regimes of the flight envelope, including variations in speed (subsonic, transonic, supersonic), angles of attack, and sideslip were investigated. Several flowfield non-linearities were present in these solutions including shock waves, vortical flows and the resulting interactions. The accuracy of this method was evaluated by comparing solutions with test data and Navier-Stokes solutions. The ability to accurately predict lateral-directional characteristics and control effectiveness was investigated by computing solutions with sideslip, and with deflected control surfaces. Problem set up times and computational resource requirements were documented and used to evaluate the efficiency of this approach for use in the fast paced preliminary design environment.

  17. 多学科设计优化在非常规布局飞机总体设计中的应用%Preliminary Design of Unconventional Configuration Aircraft Using Multidisciplinary Design Optimization

    Institute of Scientific and Technical Information of China (English)

    胡添元; 余雄庆


    以飞翼布局飞机总体设计为例,展示如何将多学科设计优化(MDO)方法有效地应用于非常规布局飞机总体设计.基于二级优化方法,提出一种飞机总体MDO实施流程.该流程包括系统级优化、子系统级优化(或评估)和多学科模型生成器3个部分.系统级优化的任务是优化全局设计变量,使系统目标最优.子系统级优化涉及的学科包括气动、隐身、结构、总体布置、重量和性能,其任务是调整局部设计变,满足本学科的设计要求,并使本学科目标最优,或对给定方案进行评估.多学科模型生成器的功能是根据飞机外形几何模型自动生成各学科分析模型,它是实现MDO流程自动化的一个关键环节.根据飞机MDO实施流程,集成各学科的分析模型和优化模型,建立了飞机总体MDO计算环境.应用算例表明:所提出的MDO实施流程能成功解决非常规布局飞机总体设计问题.%This article is aimed at demonstrating how multidisciplinary design optimization (MDO) can be effectively applied to the preliminary design of an unconventional configuration aircraft, using the flying wing configuration aircraft as an example.Based on the two-level optimization method, a procedure is proposed for the implementation of MDO of the aircraft preliminary design, which consists of three main parts: system level optimization, subsystem level optimization (or evaluation) and multidisciplinary model generator.The objective of the system level optimization is to obtain overall optimal performance through the adjustment of the global design variables.The subsystem lever consists of several disciplines, including aerodynamics, stealth, structure, internal layout, mass and performance.The task of the subsystem level optimization is to optimize the design goal of each discipline under the discipline constraints by the adjustment of local shape design variables.A multidisciplinary model generator is used to generate

  18. Study of Users’ Kansei on Commercial Aircraft Cockpit Interior Design%民机驾驶舱内饰设计感性评价研究

    Institute of Scientific and Technical Information of China (English)

    王黎静; 曹琪琰; 莫兴智; 俞金海; 李宝峰


    基于感性工学方法,研究民用飞机驾驶舱内饰设计的设计要素和用户感性评价之间的关系。通过分析感性工学方法的一般流程,结合驾驶舱内饰设计的特点,通过驾驶舱样本图片筛选、感性意向认知研究、设计要素体系构建,最终建立驾驶舱内饰设计要素和用户感性评价之间的关联模型。在方法实施过程中,使用语义差分法获取被试对样本图片的感性评价;运用形态分析法进行设计要素分解;采用反向传播(Back propagation, BP)神经网络法构建设计要素与感性评价之间的关联模型,确定设计要素和感性评价值之间的关系,实现感性评价值的预测。以驾驶舱T形区内饰为示例进行方法说明与验证,关联模型可以实现对样本感性评价值的预测,且预测值与实际主观评价值保持一致。结果表明,建立的关联模型是可用于驾驶舱内饰感性评价值的预测,感性工学方法可以应用于驾驶舱的内饰设计的感性评价。%Kansei engineering(KE) is applied to study the relationship between commercial aircraft cockpit interior design and users’ kansei. Through studying the procedure of KE and the characteristics of cockpit interior design, the process of KE in the field of commercial aircraft cockpit interior is introduced, which contains four steps: selection of picture samples, study of users’ kansei, construction of design element index and construction of the association model. Semantic differential method is used to obtain users’ kansei values. Morphological analysis is used to study the design elements. The relationship model between users’ feelings and design elements is found based onback propagation artificial neural. The example of cockpit T-shape area shows the result of the predicted kansei values and the users’ subjective kansei values agreed. This proves the relationship model can be used to predict the kansei

  19. Aircraft Carriers

    DEFF Research Database (Denmark)

    Nødskov, Kim; Kværnø, Ole

    in Asia and will balance the carrier acquisitions of the United States, the United Kingdom, Russia and India. China’s current military strategy is predominantly defensive, its offensive elements being mainly focused on Taiwan. If China decides to acquire a large carrier with offensive capabilities......, then the country will also acquire the capability to project military power into the region beyond Taiwan, which it does not possess today. In this way, China will have the military capability to permit a change of strategy from the mainly defensive, mainland, Taiwan-based strategy to a more assertive strategy...... catapult with which to launch the fi ghter aircraft, not to mention the possible development of a nuclear power plant for the ship. The Russian press has indicated that China is negotiating to buy SU-33 fi ghters, which Russia uses on the Kuznetsov carrier. The SU-33 is, in its modernized version...

  20. Aircraft Combat Survivability Estimation and Synthetic Tradeoff Methods

    Institute of Scientific and Technical Information of China (English)

    LI Shu-lin; LI Shou-an; LI Wei-ji; LI Dong-xia; FENG Feng


    A new concept is proposed that susceptibility, vulnerability, reliability, maintainability and supportability should be essential factors of aircraft combat survivability. A weight coefficient method and a synthetic method are proposed to estimate aircraft combat survivability based on the essential factors. Considering that it takes cost to enhance aircraft combat survivability, a synthetic tradeoff model between aircraft combat survivability and life cycle cost is built. The aircraft combat survivability estimation methods and synthetic tradeoff with a life cycle cost model will be helpful for aircraft combat survivability design and enhancement.

  1. Aerodynamic Design and Research for Wing-mounted-engine Integration of Civil Aircraft%民用飞机发动机一体化气动设计相关技术初探

    Institute of Scientific and Technical Information of China (English)



    Aerodynamic design of aircraft-engine integration is an important part for wing-mounted-engine air-craft design. In order to solve the design problems between aircraft and engine, many solutions were made attempts from different perspectives during the design process, and classic technology patents and valuable experience were formed. Some of the technology solutions are to be discussed as follows to reveal the map and tendency of related integrated design technology.%飞机发动机一体化气动设计是翼吊布局飞机设计的重要组成部分. 为解决飞机与发动机之间的一体化设计问题,人们在设计过程中从不同角度尝试众多解决方案,形成很多典型技术专利,积累了宝贵经验. 通过分析较为典型的方案,以展现一体化气动设计技术发展的脉络和趋势.

  2. Aircraft Electric Secondary Power (United States)


    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.

  3. On the development of a heuristic routing application for the automatic wire harness design in the aircraft

    NARCIS (Netherlands)

    Zhu, Z.; Van Tooren, M.J.L.; Van der Elst, S.W.G.


    Based on the use of dedicated software tools, Knowledge Based Engineering (KBE) techniques are able to capture and reuse engineering product and process knowledge to reduce time and cost during product development. In this paper a conceptual design of an automatic wire harness routing application is

  4. Robust matching design optimization for wing aerodynamic characteristic of aircraft family%飞机系列机翼气动特性稳健匹配优化设计

    Institute of Scientific and Technical Information of China (English)

    蒙文巩; 马东立


    在现代大型客机系列的设计中,机翼常作为通用模块,在每个型号上使用.针对各个型号因使用任务要求不同而使得对机翼气动特性需求不同的问题,引入设计权重,提出机翼气动特性匹配设计概念,建立了机翼气动特性匹配设计模型.并分析了设计权重的不确定性对机翼气动特性的影响,建立了稳健匹配优化设计模型,最终完成某高亚音速客机系列机翼气动特性稳健匹配优化设计.研究结果表明:与传统优化方法相比,稳健优化设计能够减小飞机系列中机翼在各型号上的气动特性差异,降低了设计权重的不确定性对机翼气动特性的影响,提高了飞机系列的气动性能.%The wing component is served as a common module and sharing in every model of modern aircraft family. Due to the different mission of every model, the aerodynamic requirement of wing in the aircraft family is different. The design-ratio was inducted and the matching design optimization concept for the wing aerodynamic characteristics was presented. The corresponding models with the parameter of the model design-ratio were established. The impact of the uncertainty of the design-ratio acting on the wing aerodynamic was analyzed. The model of robust matching design optimization (RMDO) for the functional module characteristics of the aircraft family was built. RMDO for the wing aerodynamic characteristics of a transonic aircraft family with two models was accomplished. The results indicate that the wing aerodynamic difference of every model in the aircraft family and the impact of the uncertainty of the design-ratio acting on the wing aerodynamic reduce based on RMDO. And the aerodynamic performance of the aircraft is improved.

  5. Optics in aircraft engines (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. Hydrogen aircraft technology (United States)

    Brewer, G. D.


    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.

  7. Application of Reliability Design in Civil Aircraft Environment Control System%可靠性设计在民用飞机环控系统中的应用

    Institute of Scientific and Technical Information of China (English)



    民用飞机环控系统可靠性设计的目标是保证飞机达到规定的可靠性定量指标和定性要求,以提高飞机的可靠度,降低运营费用,使飞机具有良好的经济性和市场竞争能力。民用飞机环控系统在设计中大量采用了冗余设计、成熟技术及标准化设计等设计手段,以保证飞机的可靠性和安全性。通过可靠性分析验证飞机平均故障间隔时间和签派可靠度是否满足环控系统设计要求。%The purpose of the reliability design on civil aircraft environment control system is to ensure the aircraft meet the qualitative and quantitative reliability requirements, reduce the cost in working, and to make better eco-nomical and compete ability. In order to ensure the reliability and safety, a fairly large number of technology are used in aircraft environment control system design, redundancy design, mature technology and standardization de-sign . Reliability analysis is used to validate whether mean time between failures and dispatch reliability meet the re-quirement.

  8. 基于动网格高空长航时机翼优化%Dynamic mesh based wing design optimization of HALE aircraft

    Institute of Scientific and Technical Information of China (English)

    朱雄峰; 郭正; 侯中喜


    The commonly used method of wing design optimization is firstly analyzed in this paper.De-sign optimization method of the wing profile airfoil distribution along the wing span is put forward,according to the requirments of special aerodynamic performance and wing configuration features for a high altitude long endurance aircraft.Hicks-Henne parameterization method is improved against the drawback of un-smooth tailing edge,which is subsequently utilized for the construction of wing dynamic mesh.B-splines function based three-dimensional dynamic mesh generation method is proposed,as a substitute of commonly used linear interpolation based method.The customization and automation of data flow and work flow are re-alized by means of secondary development of commercial software Pointwise and Fluent,and all of the processes are integrated in iSIGHT platform.Finally,a wing optimization case for high altitude long endur-ance aircraft is studied using the aforementioned method,the optimization result shows that the endurance factor improves noticeably,indicates that the dynamic mesh based wing optimization method is an effective method.%分析了机翼设计优化的一般策略,针对高空长航时飞行器的气动性能需求和机翼构型特点,提出以机翼剖面翼型沿展向分布的设计优化;针对 Hicks-Henne 翼型参数化方法后缘不光顺的缺陷,提出了改进 Hicks-Henne翼型参数化方法;针对通常基于线性插值的三维动网格生成方式的缺陷,提出采用基于 B 样条函数的三维动网格生成;通过对商业软件 Pointwise 和 Fluent 的二次开发实现数据流和工作流的定制及自动化,并将所有流程在iSIGHT 平台下集成;优化算例表明,基于动网格的机翼优化实现提高功率因子的目标,是高空长航时机翼优化中的一种有效方法。

  9. Future aircraft networks and schedules (United States)

    Shu, Yan


    Because of the importance of air transportation scheduling, the emergence of small aircraft and the vision of future fuel-efficient aircraft, this thesis has focused on the study of aircraft scheduling and network design involving multiple types of aircraft and flight services. It develops models and solution algorithms for the schedule design problem and analyzes the computational results. First, based on the current development of small aircraft and on-demand flight services, this thesis expands a business model for integrating on-demand flight services with the traditional scheduled flight services. This thesis proposes a three-step approach to the design of aircraft schedules and networks from scratch under the model. In the first step, both a frequency assignment model for scheduled flights that incorporates a passenger path choice model and a frequency assignment model for on-demand flights that incorporates a passenger mode choice model are created. In the second step, a rough fleet assignment model that determines a set of flight legs, each of which is assigned an aircraft type and a rough departure time is constructed. In the third step, a timetable model that determines an exact departure time for each flight leg is developed. Based on the models proposed in the three steps, this thesis creates schedule design instances that involve almost all the major airports and markets in the United States. The instances of the frequency assignment model created in this thesis are large-scale non-convex mixed-integer programming problems, and this dissertation develops an overall network structure and proposes iterative algorithms for solving these instances. The instances of both the rough fleet assignment model and the timetable model created in this thesis are large-scale mixed-integer programming problems, and this dissertation develops subproblem schemes for solving these instances. Based on these solution algorithms, this dissertation also presents

  10. Scorpion: Close Air Support (CAS) aircraft (United States)

    Allen, Chris; Cheng, Rendy; Koehler, Grant; Lyon, Sean; Paguio, Cecilia


    The objective is to outline the results of the preliminary design of the Scorpion, a proposed close air support aircraft. The results obtained include complete preliminary analysis of the aircraft in the areas of aerodynamics, structures, avionics and electronics, stability and control, weight and balance, propulsion systems, and costs. A conventional wing, twin jet, twin-tail aircraft was chosen to maximize the desirable characteristics. The Scorpion will feature low speed maneuverability, high survivability, low cost, and low maintenance. The life cycle cost per aircraft will be 17.5 million dollars. The maximum takeoff weight will be 52,760 pounds. Wing loading will be 90 psf. The thrust to weight will be 0.6 lbs/lb. This aircraft meets the specified mission requirements. Some modifications have been suggested to further optimize the design.

  11. Army-NASA aircrew/aircraft integration program: Phase 4 A(3)I Man-Machine Integration Design and Analysis System (MIDAS) software detailed design document (United States)

    Banda, Carolyn; Bushnell, David; Chen, Scott; Chiu, Alex; Constantine, Betsy; Murray, Jerry; Neukom, Christian; Prevost, Michael; Shankar, Renuka; Staveland, Lowell


    The Man-Machine Integration Design and Analysis System (MIDAS) is an integrated suite of software components that constitutes a prototype workstation to aid designers in applying human factors principles to the design of complex human-machine systems. MIDAS is intended to be used at the very early stages of conceptual design to provide an environment wherein designers can use computational representations of the crew station and operator, instead of hardware simulators and man-in-the-loop studies, to discover problems and ask 'what if' questions regarding the projected mission, equipment, and environment. This document is the Software Product Specification for MIDAS. Introductory descriptions of the processing requirements, hardware/software environment, structure, I/O, and control are given in the main body of the document for the overall MIDAS system, with detailed discussion of the individual modules included in Annexes A-J.

  12. Impact of Advanced Propeller Technology on Aircraft/Mission Characteristics of Several General Aviation Aircraft (United States)

    Keiter, I. D.


    Studies of several General Aviation aircraft indicated that the application of advanced technologies to General Aviation propellers can reduce fuel consumption in future aircraft by a significant amount. Propeller blade weight reductions achieved through the use of composites, propeller efficiency and noise improvements achieved through the use of advanced concepts and improved propeller analytical design methods result in aircraft with lower operating cost, acquisition cost and gross weight.

  13. A Survey of Boost-Glide Aircraft Trajectory Design%助推-滑翔飞行器轨迹设计研究综述

    Institute of Scientific and Technical Information of China (English)

    杨秀霞; 张毅; 施建洪; 盖峻峰


    近年来,随着武器防御系统的不断发展,具有高突防能力的基于助推-滑翔概念的超声速跨大气层毪行器成为国内外的研究热点。目前国内外出现多种助推-滑翔飞行器轨迹设计方法,但较全面地对各种方法进行综合研究的文献非常有限且近期未见公开发表。通过对这方面相关文献的研究,将助推-滑翔飞行器轨迹设计的关键问题分类,总结了常见解决方案的特点和应用情况,对一些热点问题进行了探讨,并对未来的工作提出了建议。%In recent years, with the development of the weapon defense system, the hypersonic boost-glide vehicle weapon which span the atmosphere with high penetrativity become an interesting research point. At present, some methods for boost-glide aircraft trajectory design have appeared all over the world. But only a few of papers were presented about the survey of this field and that not being published recently. By the investigation of a bibliography of a lot of papers, the key problems of trajectory design were categorized and the characteristic and application of the familiar solutions were summarized, some hot problems were discussed, then the proposals for further research were presented.

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

    Energy Technology Data Exchange (ETDEWEB)

    Bradley, Thomas H.; Moffitt, Blake A.; Mavris, Dimitri N.; Parekh, David E. [Georgia Institute of Technology, Atlanta, GA 30332-0405 (United States)


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

  15. Titanium in fatigue critical military aircraft structure

    Energy Technology Data Exchange (ETDEWEB)

    Gillespie, F.


    This paper discusses the effect of fatigue requirements on titanium structure in military aircraft applications, specifically, fighter aircraft. The discussion covers how fatigue affects the design and analysis of detail parts, and how manufacturing processes affect the fatigue performance of titanium structure. Criteria for designing fighter aircraft have evolved from simple strength calculations to extremely complex computer generated analyses involving strength, durability, damage tolerance and fatigue. Fatigue life prediction is an important part of these analyses and dramatically affects the design and weight of fighter aircraft. Manufacturing processes affect fatigue performance both in a positive and negative manner. Designers must allow for the effect of these processes on titanium structure and consider the efficiency and economy of adding processes that increase fatigue life.

  16. Propulsion controlled aircraft computer (United States)

    Cogan, Bruce R. (Inventor)


    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.

  17. Simulations and Experiments of Hot Forging Design and Evaluation of the Aircraft Landing Gear Barrel Al Alloy Structure (United States)

    Ram Prabhu, T.


    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.

  18. Integrated Network of Optimizations for Aircraft Systems Project (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,...

  19. Redundancy design of aircraft secondary power distribution apparatus%飞机固态二次配电装置SPDA的余度设计

    Institute of Scientific and Technical Information of China (English)

    万波; 吴伟国


    为提高配电系统可用度,现代飞机广泛采用固态二次配电装置SPDA来取代传统的由继电器/断路器组成的配电系统,它避免了机电式控制装置在开通/关断瞬间产生的电弧,同时也提高了系统使用寿命.SPDA的高可用度除了依赖固态功率控制即SSPC技术外,在系统架构的设计上,采用了余度管理技术.其中计算技术采用了硬件的余度设计思想,而输入/输出模块则采用了软件的余度设计.在定量分析了采用余度管理技术对系统可用度的影响后,得出的结论是采用硬件余度的计算技术的可用度从原有的99.999%提高到99.99999998%,采用软件余度的输入/输出模块的可用度从99.998%提高到了99.99899999%.%In order to improve the availability of power distribution system, solid-state power distribution apparatus (SP-DA) is widely used in the modern aircrafts to replace the traditional relay/breaker composed electric distribution system. It avoids the arc phenomenon during switching on/off as occurs in traditional electric-mechanical apparatus. As a result, the system life is elongated. The high availability of SPDA depends not only on the adoption of solid state power controller (SSPC) technology but also on the redundancy management of system structure design, where the hardware redundancy design is used for computing module. The software redundancy design is employed for input/output module. After the quantitative analysis of the impact of redundancy management on the system availability, the conclusions that hardware redundancy can improve the system availability from 99,999% to 99. 999 999 98% and the software redundancy can improve the availability of input/output module from 99. 998% to 99. 998 999 99% were obtained.

  20. 飞机数字化全电刹车系统的设计%Design of Aircraft Digital Electric Braking System

    Institute of Scientific and Technical Information of China (English)

    施建洪; 漆云海; 李建海; 辛庆伟


    设计的飞机全电刹车系统,以四无刷直流电机驱动四滚珠丝杠布局的机电作动机架,取代了原来液压刹车的活塞阀门作动机架,电机通过传动装置驱动滚珠丝杠松刹刹车盘实现飞机的刹车。在硬件设计上,刹车控制器的CPU采用TI公司的电机及运动控制专用DSP2407,以满足对控制系统的性能要求;4台无刷直流电机的换相信号由可编程逻辑器件完成;对电机的驱动采用了MOSFET与栅极驱动芯片IR2130组成的功率驱动电路,实现了无刷直流电机的高效驱动。%The structure and aircraft electric braking system was presented. The piston and valve actuated housing for hy-draulic braking system was replaced by electro-mechanical actuated housing, which consisted of four motors and four ball screws. The ball screw, driven by the motor through gearing, put pressure to braking carbon stack. The CPU of digital con-troller used DSP TMS320F2407, which was designed for motor and motion control applications. The control signal for brushless DC motor was produced by programmable logic device. The motor driving circuit comprised by MOSFET IR 2130 was used to drive the motor efficiently.

  1. The Optimization Design of Door Connecting Rod Bracket Structure of Civil Aircraft%民用飞机舱门连杆支架优化研究

    Institute of Scientific and Technical Information of China (English)



    The cabin latch mechanism of civil aircraft is to prevent the door accidentally open parts. When a jam occurs forced operation, it will produce a greater internal force. The equipment door latch mechanism is all stem shape and load is small except the connecting rod bracket. Connecting rod bracket structure is complex and load is bigger. Based on analyzingresistance load ,using the finite element analysis software HyperMesh and Opti-Struct , three kinds of structure forms of connecting rod bracket are simulated. With comparison and analysis, connecting rod bracket structure satisfied equipment doors functional requirements and prototype test purpose, which provides reference for the follow-up of the real product design.%民用飞机舱门闩机构是防止舱门意外开启的机构部件。当机构发生卡阻且强制操作时,将产生较大的内力。在设备舱门闩机构中除连杆支架外都是杆形件且载荷较小,连杆支架结构形式复杂且载荷较大。在分析机构卡阻载荷的基础上使用有限元分析软件HyperMesh和Opti-Struct对三种结构形式的连杆支架进行了数值模拟。通过对比分析,得到了满足样机设备舱门功能要求和试验目的的连杆支架形式,为后续真实产品的设计提供参考。

  2. Analysis and Support Initiative for Structural Technology (ASIST) Delivery Order 0016: USAF Damage Tolerant Design Handbook: Guidelines For the Analysis and Design of Damage Tolerant Aircraft Structures (United States)


    229-4417 email: DARWIN Design Assessment of Reliability WIth INspection ( DARWIN ) is a risk analysis program for...calculating the probability of failure in turbine engine disks. With a graphical user interface for problem setup and output, DARWIN integrates finite...Analysis of Cracks Handbook (Tada, et al., 1973), • Compendium of Stress Intensity Factors (Rooke & Cartwright , 1976), • Stress Intensity Factors

  3. The Design of the The Electrical Structure Network(ESN)of the Civil Aircraft%民用飞机电通路结构网络的设计

    Institute of Scientific and Technical Information of China (English)



    An stable electrical network which has low resistances must be constituted of high conductive structures for any electrical and electronic equipments on civil aircraft, which provides electrical functions such as grounding、bonding、voltage reference、protection from electromagnetic interference and protection against lightning strike. A conventional metallic aircraft inherently provides electrical a high conductive network; at present the advanced composite aircraft requires additional electrical structure network (ESN) to provide electrical functions, due to poor electrical conductivity of composite structures compared to metal. the text introduces the electrical structure network designing for main models of the civil aircraft at present, and summarizes and concludes a general design method for the electrical structure network of civil aircraft, guiding the development of the civil aircraft in our country.%民用飞机上的任何电子电气系统都需要通过导电性较好的结构连接建立一条稳定的低阻抗电通路网络,以满足接地、导电、基准电压、防电磁干扰和闪电防护等电气性能。传统金属材料飞机自身形成了较好的结构电通路;目前较先进的碳纤维复合材料飞机由于其自身结构导电性较差,便需要设计额外的电通路结构网络(ESN)来实现上述的电气性能。通过介绍目前主流飞机的电通路结构网络方案,总结归纳出一种典型的民用飞机电通路结构网络的设计方法,对国内民用飞机的研制具有重要的意义。

  4. 高精度超声波式飞机油量传感器设计%Design of high precision ultrasonic fuel gauging sensor for aircraft

    Institute of Scientific and Technical Information of China (English)

    李小刚; 曹克强; 苏新兵; 李娜


    A kind of ultrasonic fuel gauging sensor for aircraft fuel system is devised relying on the theory of ultrasonic measuring. The sensor has merits of small bulk and weight, high precision. It can gauge the fuel quantity in each oil box of the aircraft accurately and synchronously,so it is helpful to the accurately gauging and controlling of fuel about the aircraft fuel system.%运用超声波测距原理设计了超声波式飞机燃油油量传感器.该传感器具有体积小、重量轻和精度高等优点,可以准确地、实时地测量飞机各油箱的燃油油量,有助于实现飞机燃油系统的精确测控.

  5. Unmanned aircraft systems (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...

  6. Design of an Intelligent Power Management System for Aircraft Core Processor%机载核心处理平台电源管理系统

    Institute of Scientific and Technical Information of China (English)

    湛文韬; 孙靖国; 解文涛; 韩嫚莉


    A power management system was designed according to the requirement of the integrated,modular aircraft core processor.Based on parallel power supply mode,the distributed power architecture is adopted in the system.The power transformation unit,switch array unit,intelligent control unit are designed,and intelligent management software is integrated with communication protocol.Over current protection,independent electric control,current/voltage and temperature acquisition,interactive communication control and current sharing techniques are implemented,and intelligent management,state monitoring,fault recording,and redundancy and load sharing are realized,which can improve digital and intelligent level of the power management system.The system is safe,reliable and stable,and has been verified by engineering application.%针对综合化、模块化机载核心处理平台的技术需求,构建了一种电源管理系统。该系统基于并联余度供电模式,采用分布式电源架构,设计了功率转换单元、电源开关阵列及智能控制单元,集成了智能管理软件及通讯协议,采用了过流保护、独立上下电控制、电流电压及温度采集、交互式通讯控制、均流等技术,完成了电源管理系统的智能管理、状态监测管理、故障记录及余度均流等内容,提高了电源管理系统的数字化、智能化水平。该系统安全可靠、工作稳定,并经过多次工程应用验证。

  7. The design, development, and flight test results of the Boeing 737 aircraft antennas for the ICAO demonstration of the TRSB microwave landing system (United States)

    Campbell, T. G.; White, W. E.; Gilreath, M. C.


    The Research Support Flight System, a modified Boeing 737, was used to evaluate the performance of several aircraft antennas and locations for the Time Reference Scanning Beam (TRSB) Microwave Landing System (MLS). These tests were conducted at the National Aviation Facilities Experimental Center (NAFEC), Atlantic City, New Jersey on December 18, 1975. The flight tests measured the signal strength and all pertinent MLS data during a straight-in approach, a racetrack approach, and ICAO approach profiles using the independent antenna-receiver combinations simultaneously on the aircraft. Signal drop-outs were experienced during the various approaches but only a small percentage could be attributed to antenna pattern effects.

  8. Submersible Aircraft Concept Design Study (United States)


    5.3.1 Air cushion __________________________________________________ 8 5.3.2 Hydrofoils ___________________________________________________ 8 5.3.3...Aerostatic Air Cushion Hydrostatic Single Planing Hull Twin Hulls (Floats) Hydrodynamic Surface Piercing Hydrofoil Fully Submerged Hydrofoil ... Hydrofoils Hydrofoils offer good seakeeping capabilities as well as low drag characteristics, particularly at higher speeds where frictional drag

  9. 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


    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。

  10. Research related to variable sweep aircraft development (United States)

    Polhamus, E. C.; Toll, T. A.


    Development in high speed, variable sweep aircraft research is reviewed. The 1946 Langley wind tunnel studies related to variable oblique and variable sweep wings and results from the X-5 and the XF1OF variable sweep aircraft are discussed. A joint program with the British, evaluation of the British "Swallow", development of the outboard pivot wing/aft tail configuration concept by Langley, and the applied research program that followed and which provided the technology for the current, variable sweep military aircraft is outlined. The relative state of variable sweep as a design option is also covered.

  11. Hail damage to typical aircraft surfaces. (United States)

    Hayduk, R. J.


    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.

  12. 四轮转向挂装车液压系统的设计%The Design of Hydraulic System of a Four-wheel-steering Loading Truck for Equipment Hanging on Aircraft

    Institute of Scientific and Technical Information of China (English)

    洪曼; 王志; 陈文科; 温琦; 杨力


    该文主要介绍了四轮驱动挂装车液压系统的设计原理,简要介绍了挂装车的结构设计。该挂装车采用后轮驱动、四轮转向的方式,其工作装置可以在6个自由度上进行调整,并在驻车制动、工作装置液压系统中设置应急系统,确保挂装车的作业安全。样机的研制成功证明了该挂装车液压系统的设计是合理、适用的。%This paper describes the design of the hydraulic system of the loading truck for equipment hanging on aircraft with four wheels steering. And the paper describes the design of the truck’s structure. The truck which with rear-wheel-drive and four-wheel-steering has a hanging structure which with 6-freedom. For the safety of the truck during hanging equipment on aircraft, there is an emergency hydraulic-circuit connecting to the parking hydraulic-circuit and the hanging hydraulic-circuit. The success of designing and producing the first truck proves that the design of hydraulic system of the truck is logical and useful.

  13. The Effect of Reducing Cruise Altitude on the Topology and Emissions of a Commercial Transport Aircraft



    In recent years, research has been conducted for alternative commercial transonic aircraft design configurations, such as the strut- braced wing and the truss-braced wing aircraft designs, in order to improve aircraft performance and reduce the impact of aircraft emissions as compared to a typical cantilever wing design. Research performed by Virginia Tech in conjunction with NASA Langley Research Center shows that these alternative configurations result in 20% or more reduction in fuel...

  14. Nondestructive Evaluation of Aircraft and Spacecraft Wiring (United States)

    White, John E.; Tucholski, Edward J.; Green, Robert E., Jr.


    Spacecraft, and especially aircraft, often fry well past their original design lives and, therefore, the need to develop nondestructive evaluation procedures for inspection of vital structures in these craft is extremely important. One of the more recent problems is the degradation of wiring and wiring insulation. The present paper describes several nondestructive characterization methods which afford the possibility to detect wiring and insulation degradation in-situ prior to major problems with the safety of aircraft and spacecraft.

  15. Aircraft Pitch Attitude Control using Backstepping


    Härkegård, Ola; Glad, Torkel


    A nonlinear approach to the automatic pitch attitude control problem for a generic fighter aircraft is presented. A nonlinear model describing the longitudinal equations of motion in strict feedback form is derived. Backstepping is utilized for the construction of a globally stabilizing controller with a number of free design parameters. Two tuning schemes are proposed based on the desired locally linear controller properties. The controller is evaluated using the HIRM fighter aircraft model.

  16. The Demand for Single Engine Piston Aircraft, (United States)


    composites more quickly because of the absence of certi- ficatjcr: requirements. Less conventional configurations such as carar( wings and winglets are...smooth contours and surfaces. Composites offer much promise and are already in use in winos of a number of aircraft. Winglets reduce vortex drag by...Vore Aviation Corporation in Albuquerque, NM. It is a high-wing, composite , tricycle-gear aircraft designed primarily for the training and personal

  17. Control of Next Generation Aircraft and Wind Turbines (United States)

    Frost, Susan


    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.

  18. Aircraft bi-level life cycle cost estimation

    NARCIS (Netherlands)

    Zhao, X.; Verhagen, W.J.C.; Curan, R.


    n an integrated aircraft design and analysis practice, Life Cycle Cost (LCC) is essential for decision making. The LCC of an aircraft is ordinarily partially estimated by emphasizing a specific cost type. However, an overview of the LCC including design and development cost, production cost, operati

  19. Robust Control of an Ill-Conditioned Aircraft

    DEFF Research Database (Denmark)

    Breslin, S.G.; Tøffner-Clausen, S.; Grimble, M.J.;


    A robust controller is designed for a linear model of an Advanced Short Take-Off and Vertical Landing (ASTOVL) aircraft at one operating point.......A robust controller is designed for a linear model of an Advanced Short Take-Off and Vertical Landing (ASTOVL) aircraft at one operating point....

  20. Design Concept of Sound Insulation Windows of Noise-sensitive Buildings in the Area Affected by Aircraft Noise%飞机噪声影响区域敏感建筑物隔声窗设计理念

    Institute of Scientific and Technical Information of China (English)



    以北京市首都国际机场飞机噪声为例,对飞机噪声影响区域内敏感建筑物隔声窗的设计进行研究。以1小时等效A声级LAeq作为飞机噪声影响区域内隔声窗设计时飞机噪声的评价量,并依据人对不同类型、不同时间段内噪声烦恼度的不同对LAeq值进行修正。根据修正后的LAeq值设计的隔声窗隔声量基本达到飞机噪声的防护要求。%With the aircraft noise of Beijing Capital International Airport as the object, the design of sound insulation windows for noise-sensitive buildings affected by aircraft noise is investigated. The equivalent A-weighted sound pressure level per hour LAeq is used as the evaluation index for the sound insulation window design. Then, the LAeq is corrected accord-ing to personal annoyance level associated with different type of noises and time period. The sound insulation values of the windows designed with the corrected LAeq can basically satisfy the requirement of environment protection.

  1. Survival analysis of aging aircraft (United States)

    Benavides, Samuel

    work demonstrates the development of a probabilistic corrosion failure model using survival analysis methods and techniques. Using a parsimonious approach, the coefficients of a Cox proportional hazards model were derived from a set of environmental, geographical and operational predictor variables. To determine if the variables satisfied the proportional hazard assumption, numerous statistical tests were performed---such as the equivalence tests of the log rank, Wilcoxon, Peto-Peto and Fleming-Harrington---and graphical plots generated such as observed-versus-expected plots and log(-log) survival curves. Finally, in a paradigm enhancement to current design methodologies, this dissertation place sets survival analysis modeling in the context of an emerging holistic structural integrity philosophy. While traditional aircraft design and life prediction methodologies consider only the cyclic fatigue domain without consideration to the environmental or unique operating spectrum that aircraft may fly in, a holistic approach considers the cradle-to-grave driving forces in the life of a component, such as corrosion assisted crack nucleation in a material. This dissertation, which uses real-world failure data obtained from structural aircraft components, is poised to narrow the cradle-to-grave loop and provide holistic feedback in the understanding of aircraft structural system failures.

  2. Design of Hydraulic System for DQY50 Aircraft Tractor%DQY50型飞机牵引车液压系统设计

    Institute of Scientific and Technical Information of China (English)



    This paper introduces the working principle of DQY50 aircraft tractor hydraulic system and detailed analysis and explanation of the steering system, the braking system and emergency response system.%该文论述了DQY50型飞机牵引车液压系统工作原理,重点对转向系统、制动系统和应急系统进行了详细的分析和说明.

  3. Aircraft Noise Prediction



    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...

  4. 小型飞翼布局无人机控制律设计与试飞验证%Flight Control Law Design and Flight Test for Small Flying Wing Aircraft

    Institute of Scientific and Technical Information of China (English)

    马雯; 张宁; 马蓉; 陈小龙; 张奕煊


    For a due to the cancellation of the vertical tail and horizontal tail result in decreased stability, especially unstable heading for flying-wing. We design the flight control law for the full process base on the scaled flying-wing aircraft. Taking certain type shrinkage ratio aircraft of flying-wing as the control object, analysis aerodynamic characteristics of the aircraft longitudinal and lateral directional, and using eigenstructure assignment method, respectively, the longitudinal and lateral directional add stability design. The simulation results and actual test data show that, the control law can track a desired trajectory effectively, inhibit the gust disturbance, and has great practical significance.%针对无尾飞翼布局的无人机由于取消了水平尾翼和垂直尾翼,导致纵向、横航向的稳定下降,特别是横航向变为静不安定的问题,设计一种小型飞翼布局无人机全流程飞行控制律。以某型飞翼布局飞机的缩比飞机为控制对象,分析该飞机纵向与横航向的气动特性,采用特征结构配置方式,分别对纵向与横航向进行增稳设计。仿真与实际试飞结果表明:该控制律能够很好地跟踪期望的轨迹,并能有效地抑制侧风扰动,具有良好的工程应用价值。

  5. 飞机电源系统综合实验平台设计与实现%Design and realization of universal experiment for aircraft electric power supply system

    Institute of Scientific and Technical Information of China (English)

    郝世勇; 程政


    Despite various aircraft power supply system,the needs for maintenance personnel capacity training require a universal experiment system that can carry out multiple aircraft power equipments.Comprehensive and universal design method and modern measurement technology,such as computer measurement,virtual instruments,etc are used in the expetriment system.The experiment system can take experiment on aircraft main power system,secondary electrical power source,power system accessories,etc.The result shows that the universal experiment has a fine and reliable performance and reach to the design requirement.%针对军用飞机电源系统种类多,为保证在一种实验平台上实现多种电源装备的实验训练,满足机务维护人员能力培训的要求,研究设计了飞机电源系统综合实验平台。实验平台采用综合化、通用化的设计思路,综合运用计算机测控、虚拟仪器等现代测试技术,可实现飞机主电源系统、二次电源、控制保护类附件的性能测试实验,并具备新型设备的拓展实验能力。通过开展实验教学,证明该实验平台功能完善,性能稳定,设计方案合理,能够满足飞机电源系统通用性实验要求,具有很强的推广应用价值。

  6. Dynamically Scaled Modular Aircraft for Flight-Based Aviation Safety Research Project (United States)

    National Aeronautics and Space Administration — Area-I, Incorporated personnel have led the design, fabrication, and flight testing of twelve unmanned aircraft and one manned aircraft. Partnered with NASA and...

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


    Chu, Liu


    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...

  8. Design and Development of Civil Aircraft Flight Performance Auxiliary Calculation System%民用飞机的飞机性能辅助计算系统设计与开发

    Institute of Scientific and Technical Information of China (English)

    褚双磊; 董奇; 刘子昂; 温瑞英


    The performance engineer's daily work in the airline is that making the low-speed performance analysis and route operation evaluation by the software performance corresponding to aircraft model,it has a large amount of daily performance calculation. The research is oriented by pre-flight performance assis-tant calculation of performance engineer, the aircraft performance auxiliary calculation software was de-signed and developed. First it established basic performance database of civil aircraft,including aerody-namic data and engine thrust data,the programming language was used in order to complete the primary basic performance calculation, senior professional performance calculation performance curves output of the three main module design,the daily work of the performance engineers achieved quick and simple cal-culation,it laid the data foundation for the follow-up aircraft professional performance calculation,at the same time,it can offer help for the daily performance training of flight dispatcher.%航空公司性能工程师的日常工作就是使用机型对应的飞机性能软件进行低速性能分析和航线评估,日常计算量很大.面向性能工程师的前期飞行性能辅助计算工作,设计并开发了一款飞机性能辅助计算软件,建立机型基础性能数据库,包含气动数据和发动机推力数据,采用编程语言依次完成初级基础性能计算、高级专业性能计算、性能曲线绘制3个主要模块设计、实现性能工程师日常工作的快捷和简便性计算,为后续专业飞机性能计算打下数据基础,同时也可以为飞行签派员的日常性能训练工作提供帮助.

  9. Aircraft operations management manual (United States)


    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.

  10. 基于LabVIEW的飞机地面电源监控系统设计与实现%Design and implementation of aircraft ground power supply monitoring system based on LabVIEW

    Institute of Scientific and Technical Information of China (English)

    程绪刚; 邱智; 郝世勇


    Since the complex situation and different electricity demands of aircraft from ground power supply,the ground power supply system is affected. Traditional instruments couldn’t monitor the whole working process of ground power supply,to ensure high power quality and stable performance of the ground power supply,the aircraft ground power supply monitoring system based on LabVIEW software is designed. The ground power supply is monitored and recorded in real⁃time by the parameters of voltage,frequency,harmonic content and so on,the status of ground power supply is judged with reference standard,an effec⁃tive method is provided to maintain normal operation of the ground power supply and ensure the safety electricity of the aircraft.%当地面电源向飞机供电时,由于情况复杂及飞机的用电需求各不相同,从而对地面电源产生影响。传统的仪器仪表不能监测地面电源工作时的整个过程,为保证地面电源有较高的供电品质和稳定的性能,基于LabVIEW软件设计飞机地面电源监控系统。从电压、频率、谐波含量等多个方面对地面电源进行实时监控并记录,参照一定的标准,对地面电源的状态进行判断,为维护地面电源的正常工作及保证飞机的用电安全提供了更有效的方法。

  11. 基于AHP灰色理论的飞机驾驶舱内环境设计评价%Evaluation of Interior Environmental Design of Aircraft Cockpit Based on Analytic Hierarchy Process and Grey Theory

    Institute of Scientific and Technical Information of China (English)

    冯青; 余隋怀; 初建杰; 杜鹤民


    在分析驾驶舱内环境特性的基础上,综合考虑了驾驶舱内环境中的设计因素,运用层次分析法建立了基于灰色理论的飞机驾驶舱内环境设计综合评价模型.该模型通过以定量分析为主、定性分析和定量分析相结合的方法,克服了评价的主观性和随意性,实现了对飞机驾驶舱内环境设计的全面、科学和合理的评价.最后,设计并编制了飞机驾驶舱内环境设计评价软件,解决了评价过程中大量的人工数学计算问题.%On the basis of the analysis of cockpit environmental characteristics and comprehensive consideration of the cockpit environment design factors, a comprehensive evaluation model which is based on grey theory is set up by the way of using AHP. This model mainly depends on the method of quantitative analysis, quantitative analysis and a combination. It overcomes the evaluation of the subjectivity and arbitrariness and realizes a comprehensive, scientific and reasonable evaluation towards aircraft cockpit environment design. Finally, evaluation software for aircraft cockpit design is designed and lots of artificial mathematical problems during evaluation process are solved.

  12. 基于可靠性的飞机风挡抗鸟撞优化设计%Reliability-Based Optimization Design of Aircraft Windshield for Resisting Bird Impact

    Institute of Scientific and Technical Information of China (English)

    于明; 刘永寿; 李磊; 岳珠峰


    传统的飞机风挡设计通常在确定的工况下进行,未能充分考虑实际鸟撞风挡过程中不确定性因素的影响,导致飞机鸟撞风挡的故障多发.综合考虑鸟撞飞机风挡过程中鸟体材料参数、质量、撞击速度等不确定因素的影响,以飞机风挡抗鸟撞的可靠度为约束,风挡质量为目标,基于双循环方法和近似技术建立了风挡抗鸟撞可靠性优化设计系统,利用一阶矩法进行可靠性分析,对某飞机风挡进行了基于可靠性的优化设计.实例分析证明所建风挡抗鸟撞可靠性优化设计系统可行有效.%Traditional methods for aircraft windshield design are carried out based on determinate work condition. The effect of uncertainty factors during the process of windihield impacted by bird are not fully considered, so this result in low reliability of windshield performance. The effects of uncertainty factors into as bird body material parameters, mass and inpact velocity during the process of windshield impacted by bird are considered. Reliability-based optimization design of windshield for resisting bird impact is set up according to the reliability of aircraft windshield for resisting bird impact and the windshield quality based on the double loop strategy and the approximation technique. The reliatility analysis is carried out by using the first-order reliability method. The reliability -based optimization design of aircraft wind shield for resinting bird impact is made. It is proved that this optimization design is feasible.

  13. Automation tools for flexible aircraft maintenance.

    Energy Technology Data Exchange (ETDEWEB)

    Prentice, William J.; Drotning, William D.; Watterberg, Peter A.; Loucks, Clifford S.; Kozlowski, David M.


    This report summarizes the accomplishments of the Laboratory Directed Research and Development (LDRD) project 26546 at Sandia, during the period FY01 through FY03. The project team visited four DoD depots that support extensive aircraft maintenance in order to understand critical needs for automation, and to identify maintenance processes for potential automation or integration opportunities. From the visits, the team identified technology needs and application issues, as well as non-technical drivers that influence the application of automation in depot maintenance of aircraft. Software tools for automation facility design analysis were developed, improved, extended, and integrated to encompass greater breadth for eventual application as a generalized design tool. The design tools for automated path planning and path generation have been enhanced to incorporate those complex robot systems with redundant joint configurations, which are likely candidate designs for a complex aircraft maintenance facility. A prototype force-controlled actively compliant end-effector was designed and developed based on a parallel kinematic mechanism design. This device was developed for demonstration of surface finishing, one of many in-contact operations performed during aircraft maintenance. This end-effector tool was positioned along the workpiece by a robot manipulator, programmed for operation by the automated planning tools integrated for this project. Together, the hardware and software tools demonstrate many of the technologies required for flexible automation in a maintenance facility.

  14. CID Aircraft slap-down (United States)


    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

  15. 大飞机项目风险管理规划决策系统设计与实现%Design and Development of Large Aircraft Project Risk Management Planning Decision-making System

    Institute of Scientific and Technical Information of China (English)



    风险管理是各个工程项目必须的环节之一.本文首先对现有的风险管理体系进行介绍和分析,进而完成适用于大飞机项目的风险管理规划中三大核心要素——甘特图、概率影响矩阵和角色权限控制的设计,最后完成了大飞机项目风险管理规划决策系统的实现,为项目风险识别和分析提供了良好的数据接口.%Risk management is an essential part of each project. In this paper, the existing risk management systems are introduced and analyzed, and then the three core elements-gantt chart, probability-impact matrix and role access control-of risk management plan for large aircraft project are designed. Finally the large aircraft project risk management planning decision-making system is successfully developed, providing good interfaces for risk management identification and analysis.

  16. Aircraft vibration and flutter

    Directory of Open Access Journals (Sweden)

    R. R. Aggarwal


    Full Text Available "The paper outlines the theoretical and experimental procedure one has to adopt for flutter prevention during the various stages (project, design and prototype of the development of modern aircraft. With the advent of high speed, the aerodynamic coefficients have to be calculated with due regards to the effects of compressibility, finite aspect ratio of the lifting surfaces, sweep back and other peculiar shapes of the wings. The use of thin, small aspect ratio with external masses, necessitates the computation of higher frequency modes of vibration. Single degree of freedom flutter and the effect of control surface non-linearities has also become very important. Thus, it is shown how the availability of high speed computing machines, improved experimental technique for model and full scale testing has not kept pace with the uncertainties associated with the transonic speeds, low aspect ratio and the high frequency modes. Cross-checking of theoretical and experimental results at every stage seem to be the only answer."

  17. Lightning hazards to aircraft (United States)

    Corn, P. B.


    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.

  18. 纵置双涵道式飞行器悬停控制系统设计%Design of Control System for Hover of Longitudinal Double Ducted-Fan Aircraft

    Institute of Scientific and Technical Information of China (English)

    李明喜; 项昌乐; 徐彬; 苑卫松; 智晋宁


    The design problem of the ducted fan propeller wilh compact structure, high safely, low noise is dealt with, which can provide more power than common propeller. The thrust ducted fan VTOL aircraft has good prospects for development. To the problem that, the ducted fan system dynamics, are multi-variables, and strongly coupled nonlinearity, the control system decoupled design process is presented the Longitudinal double ducted-fan aircraft flight control system characteristics are analyzed to establish the basic control system model, by using the model tracking adaptive decoupling the design control principle. The testing result shows the effectiveness in reducing the coupling between axes and the stability of the hover system.%涵道风扇较同样直径的螺旋桨能产生更大的升力,且结构紧凑、安全性高、噪音低.以此为推力装置的可垂直起降飞行器具有良好发展前景.但其系统动力学特性是属于多变量、强耦合的非线性系统,在控制系统的设计中必须进行良好的解耦设计纵置双涵道式飞行器的飞行控制系统的控制特征进行了分析,建立基本的控制系统动力学模型,利用模型跟踪解耦自适应控制系统原理进行飞行控制系统设计,并在多域机动平台上完成了验证试验,结果证明该方法有效地减小了轴间耦合,飞行器悬停状态基本稳定.

  19. 某型飞机前起落架顶起装置设计和实现%Design and Implementation of Nose Landing Gear Jack-up Equipment of an Aircraft

    Institute of Scientific and Technical Information of China (English)



    The article introduces an aircraft nose landing gear jack-up equipment which is used for simulating an aircraft's nose landing gear swerving test. The main scheme is introduced and the equipment is driven by air. The jack-up actuator is designed as body with three supports and road wheels, this kind of design can not only provide the enough strength and stiffness but also be moved easily. The electrical control section controls the magnetic exchange valve to supply air for the double-acting cylinder, this can achieve the actuator up and down. The equipment is sutably designed with not too much structures and it can be easily maintained, operated and moved, it also has breakdown protection, limit protection and urgency outage protection.%该文介绍了为配合模拟某型飞机的前轮转弯试验设计的前起落架顶起装置,给出了其总体方案。装置采用气源驱动,顶起执行机构采用三角支撑架体并配有行走轮,保证机构强度和刚度的同时又便于移动,电气控制部分控制电磁换向阀向双作用气缸供气,实现顶起机构的顶起和放下。整个装置结构紧凑、布局合理、维护简单、操作方便、移动灵活,并有故障保护、限位保护和紧急断电保护功能。

  20. Design of a new aerodynamic configuration for increasing aircraft loads%一种提高载重量的新型气动布局设计研究

    Institute of Scientific and Technical Information of China (English)

    华如豪; 叶林峰; 叶正寅


    Heavy aircraft are in favor with some special engineering. However, problems of stiffness and strength such as great deformation or even rupture emerges with the great aerodynamic loads during the design and development of heavy aircraft. To compromise the aerodynamic performance and structural behavior, a new configuration with thick airfoil, which increases the lift of the main wing by means of row-wings under the finite wing span, is designed and developed in this paper. Numerical simulation result indicates that the lift coefficient is able to be increased by 50 percent compared to the traditional single wing configuration. Moreover, with the optimization of setting proper installation angle to the posterior wing and scaling down the chord of the posterior wing, the lift-drag ratio is higher than the traditional configuration using thinner wings. The overall effect shows that the aerodynamic configuration researched in this paper provides valuable reference to the design and development of heavy aircraft.%为了兼顾大载重飞机的气动性能和结构特性,针对刚度特性较好的厚翼型提出和发展了一种新型气动布局形式,在有限的翼展限制下,通过多排翼的设计思路,提高主机翼的升力性能.数值模拟结果表明,采用新的气动布局后,与传统较薄机翼的单翼布局比较,升力特性可普遍提高50%左右.通过加装偏转角、缩小后翼弦长等进一步优化,升阻比性能也优于传统薄翼,从而表明所提出的设计方案对大载重飞机的设计和发展具有重要的参考价值.

  1. Characterization of emissions from commercial aircraft engines during the Aircraft Particle Emissions eXperiment (APEX) 1 to 3 (United States)

    The fine particulate matter emissions from aircraft operations at large airports located in areas of the U. S. designated as non-attainment for the National Ambient Air Quality Standard for PM-2.5 are of major environmental concern. PM emissions data for commercial aircraft engin...

  2. 民机非包容性转子失效危害防护设计研究%Research on hazard protection design of uncontained rotor failure on commercial aircraft

    Institute of Scientific and Technical Information of China (English)

    鲍海滨; 付仁合; 王伟


    民用飞机的发动机转子非包容性失效给飞机的安全运行带来巨大的风险,为了将这种转子非包容性失效可能带来的危害降至最小,需要合理的评估碎片的危害水平,以及采取合理的安全预防措施.尽管在FAA (Federal Aviation Administration)用于评估碎片危害水平的UEDDAM(Uncontained Engine Debris Damage Analysis Model)软件工具中采用了加强防护设计以减少碎片危害,但是没有对具体的分析流程和碎片能量衰减的计算模型进行说明.为此,在现有的碎片危害分析方法的基础上,考虑到碎片在侵彻过程中会有能量衰减,分析了降低碎片危害的三种安全预防措施,通过对比确定了加强防护设计对于降低碎片危害的重要意义及其分析的流程.通过对飞机结构中关键区域定义的理解,明确了在飞机的不同部位需要采取不同的加强防护设计,并详细介绍了整体加强防护设计和局部加强防护设计的流程.%The uncontained rotor failure of commercial aircraft turbines causes enormous risk to aircraft safe operation. In order to minimize the harm of uncontained rotor failure, it is necessary to evaluate fragments harm level rationally and adopt reasonable safety precaution. Even though the software tools of UEDDAM ( Uncontained Engine Debris Damage Analysis Model), which FAA (Federal Aviation Administration) has applied for the evaluation of uncontained rotor fragments harm level, adopt consolidation design of shielding to reduce the harm of fragments, it does not have the explanation of definite flow analysis and energy dissipation model. For this reason, on the basis of analysis methods of fragments hazard, considering the energy dissipation of the debris during the penetration, three measures on how to reduce the harm of commercial aircraft turbine rotor fragments were analyzed. By comparing a-bove measures, the important significance of strengthen safe precautionary design for

  3. Control strategies for aircraft airframe noise reduction

    Institute of Scientific and Technical Information of China (English)

    Li Yong; Wang Xunnian; Zhang Dejiu


    With the development of low-noise aircraft engine,airframe noise now represents a major noise source during the commercial aircraft's approach to landing phase.Noise control efforts have therefore been extensively focused on the airframe noise problems in order to further reduce aircraft overall noise.In this review,various control methods explored in the last decades for noise reduction on airframe components including high-lift devices and landing gears are summarized.We introduce recent major achievements in airframe noise reduction with passive control methods such as fairings,deceleration plates,splitter plates,acoustic liners,slat cove cover and side-edge replacements,and then discuss the potential and control mechanism of some promising active flow control strategies for airframe noise reduction,such as plasma technique and air blowing/suction devices.Based on the knowledge gained throughout the extensively noise control testing,a few design concepts on the landing gear,high-lift devices and whole aircraft are provided for advanced aircraft low-noise design.Finally,discussions and suggestions are given for future research on airframe noise reduction.

  4. Dynamics and control of morphing aircraft (United States)

    Seigler, Thomas Michael

    The following work is directed towards an evaluation of aircraft that undergo structural shape change for the purpose of optimized flight and maneuvering control authority. Dynamical equations are derived for a morphing aircraft based on two primary representations; a general non-rigid model and a multi-rigid-body. A simplified model is then proposed by considering the altering structural portions to be composed of a small number of mass particles. The equations are then extended to consider atmospheric flight representations where the longitudinal and lateral equations are derived. Two aspects of morphing control are considered. The first is a regulation problem in which it is desired to maintain stability in the presence of large changes in both aerodynamic and inertial properties. From a baseline aircraft model various wing planform designs were constructed using Datcom to determine the required aerodynamic contributions. Based on nonlinear numerical evaluations adequate stabilization control was demonstrated using a robust linear control design. In maneuvering, divergent characteristics were observed at high structural transition rates. The second aspect considered is the use of structural changes for improved flight performance. A variable span aircraft is then considered in which asymmetric wing extension is used to effect the rolling moment. An evaluation of the variable span aircraft is performed in the context of bank-to-turn guidance in which an input-output control law is implemented.

  5. AIRTV: Broadband Direct to Aircraft (United States)

    Sorbello, R.; Stone, R.; Bennett, S. B.; Bertenyi, E.


    Airlines have been continuously upgrading their wide-body, long-haul aircraft with IFE (in-flight entertainment) systems that can support from 12 to 24 channels of video entertainment as well as provide the infrastructure to enable in-seat delivery of email and internet services. This is a direct consequence of increased passenger demands for improved in-flight services along with the expectations that broadband delivery systems capable of providing live entertainment (news, sports, financial information, etc.) and high speed data delivery will soon be available. The recent events of Sept. 11 have slowed the airline's upgrade of their IFE systems, but have also highlighted the compelling need for broadband aeronautical delivery systems to include operational and safety information. Despite the impact of these events, it is estimated that by 2005 more than 3000 long haul aircraft (servicing approximately 1 billion passengers annually) will be fully equipped with modern IFE systems. Current aircraft data delivery systems, which use either Inmarsat or NATS, are lacking in bandwidth and consequently are unsuitable to satisfy passenger demands for broadband email/internet services or the airlines' burgeoning data requirements. Present live video delivery services are limited to regional coverage and are not readily expandable to global or multiregional service. Faced with a compelling market demand for high data transport to aircraft, AirTV has been developing a broadband delivery system that will meet both passengers' and airlines' needs. AirTV is a global content delivery system designed to provide a range of video programming and data services to commercial airlines. When AirTV is operational in 2004, it will provide a broadband connection directly to the aircraft, delivering live video entertainment, internet/email service and essential operational and safety data. The system has been designed to provide seamless global service to all airline routes except for those

  6. Digital adaptive control laws for VTOL aircraft (United States)

    Hartmann, G. L.; Stein, G.


    Honeywell has designed a digital self-adaptive flight control system for flight test in the VALT Research Aircraft (a modified CH-47). The final design resulted from a comparison of two different adaptive concepts: one based on explicit parameter estimates from a real-time maximum likelihood estimation algorithm and the other based on an implicit model reference adaptive system. The two designs are compared on the basis of performance and complexity.

  7. Depreciation of aircraft (United States)

    Warner, Edward P


    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.

  8. Solar thermal aircraft (United States)

    Bennett, Charles L.


    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.

  9. Aircraft Fire Protection Laboratory (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...

  10. Aircraft Fire Protection Laboratory (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...

  11. Unmanned aircraft systems as wingmen (United States)

    Garcia, Richard; Barnes, Laura; Fields, MaryAnne


    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.

  12. 三轴式无人旋翼飞行器及自适应飞行控制系统设计%A Design of Triaxial Unmanned Rotor Aircraft and Its Adaptive Flight Control System

    Institute of Scientific and Technical Information of China (English)

    夏青元; 徐锦法


    A tri-axial unmanned rotor aircraft consisting of three sets of coaxial rotors is designed. The control mechanism of the unmanned rotor aircraft is very much simplified. The rotors are directly driven by DC motors. The speed of each motor is the only regulating variable which could control the attitude and trajectory of the aircraft. In order to verify the design of the flight control system for the triaxial unmanned rotor aircraft, a nonlinear dynamic model of the aircraft is investigated. A computing method of the rotor aerodynamic loads is established by means of the blade element momentum theory. The effect of the rotor inflow characteristics on the rotor aerodynamic load is analyzed. The validity of the rotor aerodynamic load model for the co-axial rotor is tested by experiments. Due to the influence of nonlinearity and un-modeled dynamics, it is quite difficult to establish a very accurate mathematical model, which makes it a challenge to design a flight control system. In this paper, a rotational dynamical model inverse controller and translational dynamical model inverse controller are deduced according to the nonlinear model of the aircraft. The model inverse error is adaptively compensated with an online neural network. The command following error is regulated with a PD/PI controller. A combined maneuver flight mission task element is applied to simulation validation, which included pirouette and vertical maneuvers. A demonstration is conducted to validate the flight control system of the tri-axial unmanned rotor aircraft. Simulation results including an imitation of gust disturbance are provided. The demonstration shows clearly that the designed flight control system has adaptability and robustness, and that it can implement accurate command following control.%设计了一种操控简便的三轴式无人旋翼飞行器,由三组共轴双旋翼组成,各旋翼由直流电机直接驱动,只需调节各电机转速就能控制旋翼飞行器运动姿态

  13. Automatic aircraft recognition (United States)

    Hmam, Hatem; Kim, Jijoong


    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.

  14. 航空武器系统通用数据管理平台的设计与实现%Design and Implementation of the General Data Management Platform for Weapon System of Aircraft

    Institute of Scientific and Technical Information of China (English)

    胡宇; 周德云; 汪凌霄


    针对传统航空武器电子系统设计中存在的数据管理混乱和低效问题,提出了一种基于数据库的管理平台对整个设备与接口控制信息进行管理的方案。基于三层开放式结构,建立了以SQL Server为数据库引擎,结合XML进行数据管理的模型,实现了对数据存储、数据操作以及终端管理的功能,形成了拥有丰富接口的开放式武器系统辅助设计平台。该平台具有友好的人机界面和良好的可扩展性,并在作战飞机航空武器仿真系统中得到应用。%Aimed at the management chaos and ineffectiveness in traditional designing for weapon system of aircraft, gave a solution based on database technologies to manage the equipments and interface data during the weapon system designing. Based on the open structure with three layers, founded a model using SQL Server as the database engine and XML as the storage tool. Implemented the platform with the functions of data storage, data operation and terminal management, which also have open and abundant interface for developers of weapon system and its simulation system. The practice shows that this platform can improve the efficiency of the development in weapon system of aircraft, and effectively avoid mistakes.

  15. Model of open rotor engine for aircraft conceptual design%面向飞机总体设计的开式转子发动机分析模型

    Institute of Scientific and Technical Information of China (English)

    张帅; 余雄庆


    A rapid analysis model of the open rotor engine, which can be used in aircraft conceptual design, was established by the combination of the test data of high speed propfan and approximate model of turboshaft. The performance, mass and size of the open rotor en- gine were able to be predicted quickly by this model with a small amount of input parame- ters. The precision of the model was validated by the experimental data from the references. The model developed in the paper can be used in the aircraft conceptual design to evaluate the benefits of using open rotor engines.%应用高速桨扇试验数据与涡轴核心机估算模型相结合的方法,建立了一种快速的、能用于飞机总体方案论证阶段的开式转子发动机分析模型.它使用少量的总体参数即可估算出开式转子发动机推力与耗油率特性、质量和外形尺寸,计算速度快.通过对比模型的估算结果与文献的试验数据,证明其精度能够满足飞机总体初步方案论证的要求,可用于评估采用开式转子发动机带来的收益.

  16. Fundamentals of aircraft and rocket propulsion

    CERN Document Server

    El-Sayed, Ahmed F


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

  17. Recognition of aircraft using HRR features

    NARCIS (Netherlands)

    Kossen, A.S.


    Automated target recognition (ATR) based on high resolution radar (HRR) features can be used to increase the confidence in aircraft class. Standard radar systems are not designed for performing classification and uses additional identification systems. It is shown that with the use of features the a

  18. Perspectives of civil aircraft avionics development

    Directory of Open Access Journals (Sweden)

    А. В. Наумов


    Full Text Available Considered are main directions for civil avionics development. General requirements for airborne equipment functions. Analysis of airborne avionics selection per architecture and economical effectiveness in made. Proposed is the necessity of new approach to integrated avionics complex design, first of all, on basis of mathematical method for aircraft equipment and technical characteristics definition

  19. A NASA study of the impact of technology on future sea based attack aircraft (United States)

    Hahn, Andrew S.


    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.

  20. Advanced materials for aircraft engine applications. (United States)

    Backman, D G; Williams, J C


    A review of advances for aircraft engine structural materials and processes is presented. Improved materials, such as superalloys, and the processes for making turbine disks and blades have had a major impact on the capability of modern gas turbine engines. New structural materials, notably composites and intermetallic materials, are emerging that will eventually further enhance engine performance, reduce engine weight, and thereby enable new aircraft systems. In the future, successful aerospace manufacturers will combine product design and materials excellence with improved manufacturing methods to increase production efficiency, enhance product quality, and decrease the engine development cycle time.

  1. 基于MEGA328P的四旋翼飞行器设计%Design of Four Rotor Aircraft Based on MEGA328P

    Institute of Scientific and Technical Information of China (English)

    颜浩; 徐康; 祝加雄


    The aircraft was based on the MEGA328P as the core control of the four axis flight model. The system consisted of control module, power module, communication module, sensor module, brushless motor module, a frame. First, the correct flight attitude of the sensor data was processed by using the attitude of the four elements, then controled motor with PID algorithm, Finally, we realized the free flight, high flight, GPS navigation, aerial photography and other functions. Experiments showed that the system worked stably and was suitable for the students to study and study independently.%该飞行器是基于MEGA328P为核心控制的四轴飞行模型。系统由飞控模块、电源模块、通信模块、传感器模块、无刷电机模块、机架等组成。利用四元数姿态算法对传感器数据进行处理得到正确的飞行姿态,然后采用PID算法控制电机,实现自由飞行、定高飞行、GPS导航、航拍等功能。实验表明,系统工作稳定,适合大学生自主学习和研究。

  2. Small Autonomous Aircraft Servo Health Monitoring (United States)

    Quintero, Steven


    Small air vehicles offer challenging power, weight, and volume constraints when considering implementation of system health monitoring technologies. In order to develop a testbed for monitoring the health and integrity of control surface servos and linkages, the Autonomous Aircraft Servo Health Monitoring system has been designed for small Uninhabited Aerial Vehicle (UAV) platforms to detect problematic behavior from servos and the air craft structures they control, This system will serve to verify the structural integrity of an aircraft's servos and linkages and thereby, through early detection of a problematic situation, minimize the chances of an aircraft accident. Embry-Riddle Aeronautical University's rotary-winged UAV has an Airborne Power management unit that is responsible for regulating, distributing, and monitoring the power supplied to the UAV's avionics. The current sensing technology utilized by the Airborne Power Management system is also the basis for the Servo Health system. The Servo Health system measures the current draw of the servos while the servos are in Motion in order to quantify the servo health. During a preflight check, deviations from a known baseline behavior can be logged and their causes found upon closer inspection of the aircraft. The erratic behavior nay include binding as a result of dirt buildup or backlash caused by looseness in the mechanical linkages. Moreover, the Servo Health system will allow elusive problems to be identified and preventative measures taken to avoid unnecessary hazardous conditions in small autonomous aircraft.

  3. 有人/无人机编队三位可视化系统的软件设计与实现%Design and implementation of manned/unmanned aircraft formations in 3D visualization

    Institute of Scientific and Technical Information of China (English)

    李一波; 王仓库; 姬晓飞


    针对未来有人/无人机混合编队的作战模式和增强三维可视化虚拟实现效果的需求,设计了在某无人机真实的Simulink模型的基础上结合FlightGear和MFC的有人/无人机编队三维可视化系统。系统充分利用FlightGear的强大视景系统、MATLAB⁃Simulink快速解算控制算法的能力、MFC开发的应用程序以及各个功能模块结构化,使得三维可视化系统的飞行数据和飞行视景具有时序性、可视性,各模拟模块可以根据不同的需求进行更改、升级和替代。经过多次仿真实验,该系统占用资源少,实现了有人/无人机混合编队的编队飞行和空战演示的整个过程的三维可视化显示,具有很好的三维可视化效果,达到了有人/无人机编队三维可视化系统项目的要求。%For future war modes requiring cooperative engagements that mix manned aircrafts with unmanned auto⁃motive vehicles ( UAVs) and for enhancing the 3D visualized virtual realization effect, a manned/unmanned aircraft formation 3D visualization system based on Simulink model, FlightGear, and MFC was designed. The system makes full use of FlightGear′s powerful visual system, the control algorithm′s fast calculating ability on MATLAB Simu⁃link, the application procedure developed by MFC, and the structuring of each functional module to make the flight data and flight vision sequential and visible and to enable each simulation module to be renewable, updatable, and exchangeable. Numerous simulation experiments indicate that this system requires a small amount of resources to implement a series of 3D visual displays of the entire process, including formation flight simulation, air combat demonstrations, weather conditions, and geographical environments. The system has a good 3D visualization effect and satisfies the requirements for a 3D visualization system for manned/unmanned aircraft formations.

  4. Identification of Aircraft Hazards

    Energy Technology Data Exchange (ETDEWEB)

    K. Ashley


    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, 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).


    Energy Technology Data Exchange (ETDEWEB)

    K.L. Ashley


    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, 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).

  6. Aircraft Operations Classification System (United States)

    Harlow, Charles; Zhu, Weihong


    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.

  7. A strategic planning methodology for aircraft redesign (United States)

    Romli, Fairuz Izzuddin

    Due to a progressive market shift to a customer-driven environment, the influence of engineering changes on the product's market success is becoming more prominent. This situation affects many long lead-time product industries including aircraft manufacturing. Derivative development has been the key strategy for many aircraft manufacturers to survive the competitive market and this trend is expected to continue in the future. Within this environment of design adaptation and variation, the main market advantages are often gained by the fastest aircraft manufacturers to develop and produce their range of market offerings without any costly mistakes. This realization creates an emphasis on the efficiency of the redesign process, particularly on the handling of engineering changes. However, most activities involved in the redesign process are supported either inefficiently or not at all by the current design methods and tools, primarily because they have been mostly developed to improve original product development. In view of this, the main goal of this research is to propose an aircraft redesign methodology that will act as a decision-making aid for aircraft designers in the change implementation planning of derivative developments. The proposed method, known as Strategic Planning of Engineering Changes (SPEC), combines the key elements of the product redesign planning and change management processes. Its application is aimed at reducing the redesign risks of derivative aircraft development, improving the detection of possible change effects propagation, increasing the efficiency of the change implementation planning and also reducing the costs and the time delays due to the redesign process. To address these challenges, four research areas have been identified: baseline assessment, change propagation prediction, change impact analysis and change implementation planning. Based on the established requirements for the redesign planning process, several methods and

  8. Design of Model Aircraft Wireless Transceiver System Based on RF Chip A7105%基于射频芯片A7105的航模无线收发系统的设计

    Institute of Scientific and Technical Information of China (English)

    吴毅强; 曾永安; 廖昆明; 邓淼


    A 2.4 GHz six channels model aircraft wireless transceiver system was designed based on the wireless transceiver chip A7105 and the single chip WT51F516. The core modules of this wireless transceiver system were radio frequency chip A7105 and power amplifier chip AP1 110, and frequency hopping mechanism was applied for data transmission. 50 ft Impedance matching circuits were obtained by analyzing impedance characteristics of peripheral circuit of radio frequency chip A7105 and antenna based on ADS software. The system was successfully realized the transmitting and received wireless signals within 100 meters. The system has the characteristics of low cost, small power consumption and far receiving distance. This could be applied in low-end model aircraft.%基于射频收发芯片A7105,通过单片机WT51F516的控制处理,设计了一款2.4 GHz六通道航模无线收发系统.此无线收发系统核心部件采用射频芯片A7105与功放芯片AP1110,并使用跳频机制进行数据传输.基于ADS软件分析射频芯片外围电路和天线的阻抗特性并得到了50Ω阻抗匹配电路.此系统成功实现了100m范围内的无线信号发射接收,具有成本低廉、功耗小、接收距离远的特点,并且能够应用在中低端航模中.

  9. Utilizing High Fidelity Simulations in Multidisciplinary Optimization of Aircraft Systems Project (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,...

  10. Ride quality systems for commuter aircraft (United States)

    Downing, D. R.; Hammond, T. A.; Amin, S. P.


    The state-of-the-art in Active Ride Augmentation, specifically in terms of its feasibility for commuter aircraft applications. A literature survey was done, and the principal results are presented here through discussion of different Ride Quality Augmentation System (RQAS) designs and advances in related technologies. Recommended follow-on research areas are discussed, and a preliminary RQAS configuration for detailed design and development is proposed.

  11. Propeller aircraft interior noise model utilization study and validation (United States)

    Pope, L. D.


    Utilization and validation of a computer program designed for aircraft interior noise prediction is considered. The program, entitled PAIN (an acronym for Propeller Aircraft Interior Noise), permits (in theory) predictions of sound levels inside propeller driven aircraft arising from sidewall transmission. The objective of the work reported was to determine the practicality of making predictions for various airplanes and the extent of the program's capabilities. The ultimate purpose was to discern the quality of predictions for tonal levels inside an aircraft occurring at the propeller blade passage frequency and its harmonics. The effort involved three tasks: (1) program validation through comparisons of predictions with scale-model test results; (2) development of utilization schemes for large (full scale) fuselages; and (3) validation through comparisons of predictions with measurements taken in flight tests on a turboprop aircraft. Findings should enable future users of the program to efficiently undertake and correctly interpret predictions.

  12. Nonlinear Gust Response Analysis of Free Flexible Aircraft

    Directory of Open Access Journals (Sweden)

    Chen Shilu


    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.

  13. Advanced Aircraft Material

    Directory of Open Access Journals (Sweden)

    Vivek Kumar Prince


    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

  14. Aircraft Crash Survival Design Guide. Volume 5. Aircraft Postcrash Survival (United States)


    a scale where asbestos cement board is zero and select-grade red oak flooring is 100. No additional heat flux is supplied beyond that generated tendency, causing the rotor blades to strike the water. Also, compressor blades very often become salt- incrusted and stall shortly after

  15. Aircraft Crash Survival Design Guide. Volume 5. Aircraft Postcrash Survival (United States)


    Expanded aluminum foil a Open pore sponge foam * Reticulated sponge foam * Rigid plastic foam * Closed pore sponge foam 82 Proximity 1 Proximity 2...of exposure. In oiler to predict performance in a fire, heat release data must be obtained over a range of heat flux levels. Most cellulosic materials

  16. Design and Implementation of a Certain Self-propelled Anti-aircraft Gun Floating Parameter Monitoring System%某自行高炮浮动参数监测系统的设计与实现

    Institute of Scientific and Technical Information of China (English)

    孙致远; 郑坚; 熊超; 殷军辉


    为了能够实时掌握自行高炮自动机性能,提高装备的可靠性,利用无线传感器网络技术,设计并建立了自行高炮浮动参数监测系统。该监测系统利用磁致伸缩位移传感器,实现了后坐位移的精确测量;设计了一种具有高速采集和片上处理功能的无线传感器网络节点,实现了数据的采集、储存与无线传输;开发了上位机软件,能够根据回传数据,完成后坐曲线的显示和浮动参数的自动提取。实弹测试试验表明,该监测系统能够基本满足自行高炮浮动参数在线监测的要求。%For the purpose of keeping track of the performance of the auto-mechanism of self-propelled anti-aircraft gun and improve its reliability,the floating parameter monitoring system of self-propelled anti-aircraft gun was designed and established based on the wireless sensor networks (WSNs)technolo-gy. In the monitoring system,the magnetostriction displacement sensors were used to successfully and accurately pick up the recoil displacement. A WSN node with high speed acquisition and on-chip pro-cessing was designed to realize the data collection,storage and wireless transmission. The host compu-ter software was designed to achieve the recoil curve display and the floating parameter automation ex-traction according to the data received. The firing test shows that the system can basically satisfy the floating parameter on-line monitoring requirement.

  17. Aircraft Fuel Systems Career Ladder. (United States)


    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

  18. 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


    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.

  19. A Study of Vehicle Structural Layouts in Post-WWII Aircraft (United States)

    Sensmeier, Mark D.; Samareh, Jamshid A.


    In this paper, results of a study of structural layouts of post-WWII aircraft are presented. This study was undertaken to provide the background information necessary to determine typical layouts, design practices, and industry trends in aircraft structural design. Design decisions are often predicated not on performance-related criteria, but rather on such factors as manufacturability, maintenance access, and of course cost. For this reason, a thorough understanding of current best practices in the industry is required as an input for the design optimization process. To determine these best practices and industry trends, a large number of aircraft structural cutaway illustrations were analyzed for five different aircraft categories (commercial transport jets, business jets, combat jet aircraft, single engine propeller aircraft, and twin-engine propeller aircraft). Several aspects of wing design and fuselage design characteristics are presented here for the commercial transport and combat aircraft categories. A great deal of commonality was observed for transport structure designs over a range of eras and manufacturers. A much higher degree of variability in structural designs was observed for the combat aircraft, though some discernable trends were observed as well.

  20. 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)



    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。

  1. Aircraft-skin Infrared Radiation Characteristics Modeling and Analysis

    Institute of Scientific and Technical Information of China (English)

    Lu Jianwei; Wang Qiang


    One of the most important problems of stealth technology is to evaluate the infrared radiation (IR) level received by IR sensors from fighters to be detected. This article presents a synthetic method for calculating the IR emitted from aircraft-skin. By reckoning the aerodynamic heating and hot engine casing to be the main heat sources of the exposed aircraft-skin, a numerical model of skin temperature distribution is established through computational fluid dynamics (CFD) technique. Based on it, an infrared signature model for solving the complex geometry and structure of a fighter is proposed with the reverse Monte Carlo (RMC) method. Finally, by way of determining the IR intensity from aircraft-skin, the aircraft components that emit the most IR can be identified; and the cooling effects of the main aircraft components on IR intensity are investigated. It is found that reduction by 10 K in the skin temperature of head, vertical stabilizers and wings could lead to decline of more than 8% of the IR intensity on the aircraft-skin in front view while at the broadside of the aircraft, the drops in IR intensity could attain under 8%. The results provide useful reference in designing stealthy aircraft.

  2. Obstacle avoidance and path planning for carrier aircraft launching

    Directory of Open Access Journals (Sweden)

    Wu Yu


    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.

  3. Nonlinear feedback control of highly manoeuvrable aircraft (United States)

    Garrard, William L.; Enns, Dale F.; Snell, S. A.


    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.

  4. Multispectral imaging of aircraft exhaust (United States)

    Berkson, Emily E.; Messinger, David W.


    Aircraft pollutants emitted during the landing-takeoff (LTO) cycle have significant effects on the local air quality surrounding airports. There are currently no inexpensive, portable, and unobtrusive sensors to quantify the amount of pollutants emitted from aircraft engines throughout the LTO cycle or to monitor the spatial-temporal extent of the exhaust plume. We seek to thoroughly characterize the unburned hydrocarbon (UHC) emissions from jet engine plumes and to design a portable imaging system to remotely quantify the emitted UHCs and temporally track the distribution of the plume. This paper shows results from the radiometric modeling of a jet engine exhaust plume and describes a prototype long-wave infrared imaging system capable of meeting the above requirements. The plume was modeled with vegetation and sky backgrounds, and filters were selected to maximize the detectivity of the plume. Initial calculations yield a look-up chart, which relates the minimum amount of emitted UHCs required to detect the presence of a plume to the noise-equivalent radiance of a system. Future work will aim to deploy the prototype imaging system at the Greater Rochester International Airport to assess the applicability of the system on a national scale. This project will help monitor the local pollution surrounding airports and allow better-informed decision-making regarding emission caps and pollution bylaws.

  5. View of QF-106 aircraft cockpit (United States)


    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.

  6. Aircraft Oxygen Generation (United States)


    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

  7. Robots for Aircraft Maintenance (United States)


    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.

  8. Aircraft noise prediction (United States)

    Filippone, Antonio


    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.

  9. Aircraft Emissions Characterization (United States)


    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


    Directory of Open Access Journals (Sweden)

    Anwar Ul Haque


    Full Text Available An analytical approach is essential for the estimation of the requirements of aerodynamic and aerostatic lift for a hybrid buoyant aircraft. Such aircrafts have two different modules to balance the weight of aircraft; aerostatic module and aerodynamic module. Both these modules are to be treated separately for estimation of the mass budget of propulsion systems and required power. In the present work, existing relationships of aircraft and airship are reviewed for its further application for these modules. Limitations of such relationships are also disussed and it is precieved that it will provide a strating point for better understanding of design anatomy of such aircraft.

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

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


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

  12. Annoyance by aircraft noise and fear of overflying aircraft in relation to attitudes toward the environment and community (United States)

    Loeb, M.; Moran, S. V.


    It has been suggested that expressions of annoyance attributable to aircraft noise may reflect in part fear of aircraft overflights and possible crashes. If this is true, then residents of areas where crashes have occurred should express more annoyance. To test this hypothesis, 50 residents of an Albany, New York area where an aircraft crash producing fatalities recently occurred and 50 residents of a comparable nearby area without such a history, were asked to respond to a 'Quality of Life Questionnaire.' Among the items were some designed to test annoyance by noise and fear of aircraft overflights. It was predicted that those in the crash area would express more fear and would more often identify aircraft as a noise source. These hypotheses were sustained. A near-replication was carried out in Louisville, Kentucky; results were much the same. Analyses indicated that for the crash-area groups, there was associating of aircraft fear and noise annoyance responses; this was true to an apparently lesser extent for non-crash groups. The greater annoyance of crash groups by aircraft community noise apparently does not carry over to situations in which aircraft noise is assessed in the laboratory.

  13. Design, analysis, and control of a large transport aircraft utilizing selective engine thrust as a backup system for the primary flight control. Ph.D. Thesis (United States)

    Gerren, Donna S.


    A study has been conducted to determine the capability to control a very large transport airplane with engine thrust. This study consisted of the design of an 800-passenger airplane with a range of 5000 nautical miles design and evaluation of a flight control system, and design and piloted simulation evaluation of a thrust-only backup flight control system. Location of the four wing-mounted engines was varied to optimize the propulsive control capability, and the time constant of the engine response was studied. The goal was to provide level 1 flying qualities. The engine location and engine time constant did not have a large effect on the control capability. The airplane design did meet level 1 flying qualities based on frequencies, damping ratios, and time constants in the longitudinal and lateral-directional modes. Project pilots consistently rated the flying qualities as either level 1 or level 2 based on Cooper-Harper ratings. However, because of the limited control forces and moments, the airplane design fell short of meeting the time required to achieve a 30 deg bank and the time required to respond a control input.

  14. Aerodynamics configuration conceptual design for ATLLAS-M6 analog transport aircraft%类 ATLLAS-M6运输机气动布局分析与设计

    Institute of Scientific and Technical Information of China (English)

    肖光明; 冯毅; 唐伟; 桂业伟


    根据德国宇航中心设计的ATLLAS-M6运输机的气动布局特点,利用基于类型函数和形状函数的CST方法对其进行了参数化建模,并初步计算分析了该外形的主要气动特性,包括配平特性、静/动稳定性以及控制面的控制效率等.研究结果表明,类ATLLAS-M6的气动性能基本满足高超声速运输机的设计要求,其气动布局方案是可以借鉴的.在此基础上,将进一步考虑运输机结构重量、热防护性能等对布局的约束,对其外形进行多学科优化设计.%The aerodynamic configuration study of ATLLAS-M6 transport aircraft proposed by the German Aerospace Center (DLR) is presented and discussed. The ATLLAS-M6 has a turbine-based combined cycle (TBCC) propulsion system, and it's aerodynamic configuration has the following characteristics: double delta-wing with low-aspect ratio, axial vertical tail, high-set horizontal tail and lifting body with high-fineness ratio. In this paper, a parameterized configuration is proposed via the "class function and shape function transformation technique" (CST) method. The aerodynamic characteristics are investigated, such as the trim characteristic, static/dynamic stability and control efficiency of control surfaces. The detail research indicated that the ATLLAS-M6 analog has a high hypersonic lift to drag ratio at the cruise state of low trimming angle of attack. The hypersonic stability derivatives predicted by the " dahlem-buck" method and the "prandtl-meyer" method shown that the transporter is static and dynamic stable in both lateral and directional directions and the proposed configuration is one of the feasible transporter choices. Yet, the aerodynamic configuration conceptual design of the hypersonic transport aircraft is a highly integrated project, several disciplines involved must be considered farther, such as structured materials and thermal protection system. Therefore, the "multidisciplinary design optimization" (MDO) method

  15. A aircraft steering gear control system hardware design%某飞行器舵机控制系统硬件设计

    Institute of Scientific and Technical Information of China (English)

    倪原; 任展鹏; 刘智平; 张晖


    研究一种基于TMS320F28335 DSP(Digital Signal Processor)的全数字飞行器控制系统的硬件设计,分析了其结构组成:主控制器电路、舵面位置检测电路和通讯等硬件电路设计.经过多次试验调试,所设计的硬件系统可以满足飞行器性能要求.%This study a hardware based on TMS320F28335 DSP ( Digital Signal Processor ) of the digital flight control system hardware design, analyzes its structure: the main controller circuit, the rudder position detection circuit and communication hardware circuit design. After many experiments, the design of hardware system can meet the requirements of vehicle performance.

  16. Braking performance of aircraft tires (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.

  17. Numerical and Experimental Investigation of the Structural Behavior during Aircraft Emergency Landing on Water


    Siemann, Martin


    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...

  18. NASA's Aeroacoustic Tools and Methods for Analysis of Aircraft Noise (United States)

    Rizzi, Stephen A.; Lopes, Leonard V.; Burley, Casey L.


    Aircraft community noise is a significant concern due to continued growth in air traffic, increasingly stringent environmental goals, and operational limitations imposed by airport authorities. The ability to quantify aircraft noise at the source and ultimately at observers is required to develop low noise aircraft designs and flight procedures. Predicting noise at the source, accounting for scattering and propagation through the atmosphere to the observer, and assessing the perception and impact on a community requires physics-based aeroacoustics tools. Along with the analyses for aero-performance, weights and fuel burn, these tools can provide the acoustic component for aircraft MDAO (Multidisciplinary Design Analysis and Optimization). Over the last decade significant progress has been made in advancing the aeroacoustic tools such that acoustic analyses can now be performed during the design process. One major and enabling advance has been the development of the system noise framework known as Aircraft NOise Prediction Program2 (ANOPP2). ANOPP2 is NASA's aeroacoustic toolset and is designed to facilitate the combination of acoustic approaches of varying fidelity for the analysis of noise from conventional and unconventional aircraft. The toolset includes a framework that integrates noise prediction and propagation methods into a unified system for use within general aircraft analysis software. This includes acoustic analyses, signal processing and interfaces that allow for the assessment of perception of noise on a community. ANOPP2's capability to incorporate medium fidelity shielding predictions and wind tunnel experiments into a design environment is presented. An assessment of noise from a conventional and Hybrid Wing Body (HWB) aircraft using medium fidelity scattering methods combined with noise measurements from a model-scale HWB recently placed in NASA's 14x22 wind tunnel are presented. The results are in the form of community noise metrics and

  19. Aircraft Bleed Air System Sense Line Design%民用飞机气源系统感压管设计

    Institute of Scientific and Technical Information of China (English)



    A method to design and intensity examination bleed air system sense line is introduced in this paper. Based on the using conditions, material and figure of sense lines are designed. An examination corresponding limit load cases and ultimate load cases is clarified. Sense line intensity examination is carried out and results show the design can meet all design requirements.%本文介绍了一种民用飞机气源系统感压管设计与强度校核的方法。根据气源系统感压管的使用环境特点,进行了选材、外形的设计。并提出了一套对应限制载荷工况和极限载荷工况的感压管的校核流程,进行了传感器感压管的校核。校核结论传感器感压管设计满足要求。

  20. Prediction of anthropometric accommodation in aircraft cockpits (United States)

    Zehner, Gregory Franklin

    Designing aircraft cockpits to accommodate the wide range of body sizes existing in the U.S. population has always been a difficult problem for Crewstation Engineers. The approach taken in the design of military aircraft has been to restrict the range of body sizes allowed into flight training, and then to develop standards and specifications to ensure that the majority of the pilots are accommodated. Accommodation in this instance is defined as the ability to: (1) Adequately see, reach, and actuate controls; (2) Have external visual fields so that the pilot can see to land, clear for other aircraft, and perform a wide variety of missions (ground support/attack or air to air combat); and (3) Finally, if problems arise, the pilot has to be able to escape safely. Each of these areas is directly affected by the body size of the pilot. Unfortunately, accommodation problems persist and may get worse. Currently the USAF is considering relaxing body size entrance requirements so that smaller and larger people could become pilots. This will make existing accommodation problems much worse. This dissertation describes a methodology for correcting this problem and demonstrates the method by predicting pilot fit and performance in the USAF T-38A aircraft based on anthropometric data. The methods described can be applied to a variety of design applications where fitting the human operator into a system is a major concern. A systematic approach is described which includes: defining the user population, setting functional requirements that operators must be able to perform, testing the ability of the user population to perform the functional requirements, and developing predictive equations for selecting future users of the system. Also described is a process for the development of new anthropometric design criteria and cockpit design methods that assure body size accommodation is improved in the future.

  1. Techno-economic requirements for composite aircraft components (United States)

    Palmer, Ray


    The primary reason for use of composites is to save structural weight. A well designed composite aircraft structure will usually save 25-30 percent of a well designed metal structure. The weight savings then translates into improved performance of the aircraft in measures of greater payload, increased flying range or improved efficiency - less use of fuel. Composite materials offer technical advantages. Key technical advantages that composites offer are high stiffness, tailored strength capability, fatigue resistance, and corrosion resistance. Low thermal expansion properties produce dimensionally stable structures over a wide range of temperature. Specialty resin 'char' forming characteristics in a fire environment offer potential fire barrier application and safer aircraft. The materials and processes of composite fabrication offer the potential for lower cost structures in the near future. The application of composite materials to aircraft are discussed.

  2. 19 CFR 10.183 - Duty-free entry of civil aircraft, aircraft engines, ground flight simulators, parts, components... (United States)


    ... Duty-free entry of civil aircraft, aircraft engines, ground flight simulators, parts, components, and... aircraft, aircraft engines, and ground flight simulators, including their parts, components, and... United States (HTSUS) by meeting the following requirements: (1) The aircraft, aircraft engines,...

  3. 飞机维修保障信息系统权限管理设计与实现%Authority management design and realization of aircraft maintenance support information system

    Institute of Scientific and Technical Information of China (English)

    张珣; 李青; 杨志峰


    针对飞机一体化维修保障信息系统复杂的权限控制需求,在RBAC模型基础上引入了“组织”这一对象,提出了改进的权限控制模型,并通过业务逻辑将权限控制细化到具体的数据对象上,实现了细粒度的访问控制。利用该模型设计了权限管理子系统,给出了权限管理的具体实现,很好地满足了系统的权限控制需求。%Aiming at complex authority control requirements for integrated maintenance support information system of aircrafts , the object“organization”and improved model of authority control were introduced on the basis of RBAC ( Role-Based Access Control) model, and authority control are refined to specific data object by business logic, thus achieving fine-grained access control. Taking the advantage of this model, subsystem of authority management was designed and the authority management was concretely realized, well meeting the authority control requirements for the system.

  4. Congestion Pricing for Aircraft Pushback Slot Allocation. (United States)

    Liu, Lihua; Zhang, Yaping; Liu, Lan; Xing, Zhiwei


    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.

  5. AASPT Carbon/Carbon Aircraft Brake Disk Granted MPA

    Institute of Scientific and Technical Information of China (English)


    @@ Xi'an Chaoma Technology Co. Ltd. was issued Parts Manufacturer Approval (PMA) for Carbon/Carbon aircraft brake disk for Airbus 320 series by Civil Aviation Administration of China (CAAC). The company is held by Academy of Aerospace Solid Propulsion Technology (AASPT), a subsidiary of China Aerospace Science and Technology Corporation (CASC). It is the first approval given to a Chinese company to design and produce brakes for main civilian aircraft.

  6. Building A Flight Control System For A Modelled Aircraft


    Garratt, Paul William; Rushton, Andrew; Yilmaz, Esat


    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...

  7. "Fan-Tip-Drive" High-Power-Density, Permanent Magnet Electric Motor and Test Rig Designed for a Nonpolluting Aircraft Propulsion Program (United States)

    Brown, Gerald V.; Kascak, Albert F.


    A scaled blade-tip-drive test rig was designed at the NASA Glenn Research Center. The rig is a scaled version of a direct-current brushless motor that would be located in the shroud of a thrust fan. This geometry is very attractive since the allowable speed of the armature is approximately the speed of the blade tips (Mach 1 or 1100 ft/s). The magnetic pressure generated in the motor acts over a large area and, thus, produces a large force or torque. This large force multiplied by the large velocity results in a high-power-density motor.

  8. The Drainage System Design of Civil Aircraft APU Door%民用飞机APU舱门排液设计

    Institute of Scientific and Technical Information of China (English)



    The oil and fuel from the APU compartment door drainage vent may enter the APU system drainage vent. The APU compartment door is close to the APU system drainage vent. So the APU compartment door drainage design is very important.%APU舱门与APU排气口距离非常近,从APU舱门排出的可燃液体很有可能会流入飞机尾锥的APU排气口,造成安全事故. APU舱门的排液如何避开APU排气口是一个非常重要的设计.

  9. Robust control of an aircraft model

    Energy Technology Data Exchange (ETDEWEB)

    Werner, H. [Bochum Univ. (Germany). Fakultaet fuer Elektrotechnik


    A new multimodel approach to robust controller design is illustrated by a practical application: for a laboratory aircraft model, a robust controller is designed simultaneously for normal operating conditions and for propeller failure. Based on a linear model for each operating mode, an LMI formulation of the problem and convex programming are used to search for a state feedback controller which achieves the objective. This state feedback design is then realized simultaneously in both operating modes by a controller which is based on fast output sampling. Robust performance is demonstrated by experimental results. (orig.)

  10. Robust control of an aircraft model

    Energy Technology Data Exchange (ETDEWEB)

    Werner, H. (Bochum Univ. (Germany). Fakultaet fuer Elektrotechnik)


    A new multimodel approach to robust controller design is illustrated by a practical application: for a laboratory aircraft model, a robust controller is designed simultaneously for normal operating conditions and for propeller failure. Based on a linear model for each operating mode, an LMI formulation of the problem and convex programming are used to search for a state feedback controller which achieves the objective. This state feedback design is then realized simultaneously in both operating modes by a controller which is based on fast output sampling. Robust performance is demonstrated by experimental results. (orig.)

  11. Airline and Aircraft Reliability


    Hauka, Maris; Paramonovs, Jurijs


    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...

  12. Slotted Aircraft Wing (United States)

    McLean, James D. (Inventor); Witkowski, David P. (Inventor); Campbell, Richard L. (Inventor)


    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.

  13. The Application of mu Analysis and Synthesis to the Control of an ASTOVL Aircraft

    DEFF Research Database (Denmark)

    Tøffner-Clausen, S.; Andersen, Palle; Breslin, S.G.;


    A robust controller is designed for a linear model of an Advanced Short Take-Off and Vertical Landing (ASTOVL) aircraft at one operating point.......A robust controller is designed for a linear model of an Advanced Short Take-Off and Vertical Landing (ASTOVL) aircraft at one operating point....

  14. Design of in-situ detector applied to aircraft radio altimeter%一种飞机无线电高度表原位检测仪的设计

    Institute of Scientific and Technical Information of China (English)

    赵波; 魏俊淦; 田建学


    To realize the in-situ detection of the aircraft radio altimeter in out-field,the in-situ detector for the altimeter was developed by taking the industrial personal computer(IPC)PC104 and embedded processor STM32 as the system core,in which the design thoughts of the functional block diagram and each module,software functional partitioning and architecture are provided. The detector can implement the altimeter signal isolation and the voltage conversion,generate the altitude simulation signal and analog signal of the indicator,and provide the check signal of the altimeter to indicate the normal signal and alarm trip signal,and to measure the linear and nonlinear altitude voltage. The design has realized the simple and friendly human-com-puter interaction,and has been used and verified in the aviation test.%基于飞机外场原位检查无线电高度表的目的,采用PC104工控机和STM32嵌入式处理器为系统核心研制了高度表原位检测仪,包括功能框图、各模块的设计思路,软件功能划分和体系结构,实现高度表信号隔离和电平转换,产生高度模拟信号、指示器模拟信号、提供高度表检查信号,对正常、告警跳闸信号进行指示,对线性高度电压、非线性高度电压进行测量,该设计实现了简便友好的人机交互,已经在航空检测中使用验证.

  15. Interaction of Aircraft Wakes From Laterally Spaced Aircraft (United States)

    Proctor, Fred H.


    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.


    Bach, R.


    The computer program SMACK (SMoothing for AirCraft Kinematics) is designed to provide flightpath reconstruction of aircraft forces and motions from measurements that are noisy or incomplete. Additionally, SMACK provides a check on instrument accuracy and data consistency. The program can be used to analyze data from flight-test experiments prior to their use in performance, stability and control, or aerodynamic modeling calculations. It can also be used in the analysis of aircraft accidents, where the actual forces and motions may have to be determined from a very limited data set. Application of a state-estimation method for flightpath reconstruction is possible because aircraft forces and motions are related by well-known equations of motion. The task of postflight state estimation is known as a nonlinear, fixed-interval smoothing problem. SMACK utilizes a backward-filter, forward-smoother algorithm to solve the problem. The equations of motion are used to produce estimates that are compared with their corresponding measurement time histories. The procedure is iterative, providing improved state estimates until a minimum squared-error measure is achieved. In the SMACK program, the state and measurement models together represent a finite-difference approximation for the six-degree-of-freedom dynamics of a rigid body. The models are used to generate time histories which are likely to be found in a flight-test measurement set. These include onboard variables such as Euler angles, angular rates, and linear accelerations as well as tracking variables such as slant range, bearing, and elevation. Any bias or scale-factor errors associated with the state or measurement models are appended to the state vector and treated as constant but unknown parameters. The SMACK documentation covers the derivation of the solution algorithm, describes the state and measurement models, and presents several application examples that should help the analyst recognize the potential

  17. 航母中线电视监视系统的设计%Design of centerline television surveillance system for aircraft landing on carriers

    Institute of Scientific and Technical Information of China (English)

    赵建川; 邵俊峰; 王弟男; 陈长青; 王锐


    A centerline camera subsystem is designed for the mother-ship recovery television surveillance sys- tem. An Electron Multiplying Charge-coupled Device(EMCCD)-based Electrical-Optical(EO) imager is pro- posed according to the requirements for illumination principle, imaging contrast and resolution. The stability of a gyro-stabilized platform and the accuracy of a centerline camera are analyzed, and several imaging processing methods are discussed to solve the problems of position and inclination angles. It is found that the EO system based on Andor Ixon EMCCD with a diameter of 40 mm can fulfill the optical requirements for the centerline camera. The F/2 optical system based on a petzval show its MTF to be close to the diffraction limit. The sta- bility and accuracy status-quo gyro-stabilized platform is enough for the surveillance system. The centroid algo- rithm and edge operator imaging processing method are proposed to calculate the altitude, latitude and inclina- tion. The designed system is capable of performing surveillance with 24-hours a day, which is suitable for air- eraft landing on earriers.%研究设计了航母中线电视监视系统。依据照度、对比度及分辨率要求提出了一套基于电子倍增电荷耦合器件(EMCCD)的光电成像系统。分析了航母中线电视监视系统的舰载稳定平台的精度要求,并探讨了该系统可采用的图像处理算法。分析表明:采用主流的AndorIxonEMCCD并配合口径为40mm的光学系统可满足照度、对比度和分辨率的要求;采用Petzval形式初步设计的F/2光学系统,其光学传递函数接近衍射极限;而现有舰载稳定平台技术可以满足指向稳定的需要。最后,分析了形心算法、边缘算子算法在获取着舰机位置和姿态角的应用。该系统具有全天候工作能力,适用于航空母舰的着舰引导。

  18. Trust Control of VTOL Aircraft Part Deux (United States)

    Dugan, Daniel C.


    Thrust control of Vertical Takeoff and Landing (VTOL) aircraft has always been a debatable issue. In most cases, it comes down to the fundamental question of throttle versus collective. Some aircraft used throttle(s), with a fore and aft longitudinal motion, some had collectives, some have used Thrust Levers where the protocol is still "Up is Up and Down is Down," and some have incorporated both throttles and collectives when designers did not want to deal with the Human Factors issues. There have even been combinations of throttles that incorporated an arc that have been met with varying degrees of success. A previous review was made of nineteen designs without attempting to judge the merits of the controller. Included in this paper are twelve designs entered in competition for the 1961 Tri-Service VTOL transport. Entries were from a Bell/Lockheed tiltduct, a North American tiltwing, a Vanguard liftfan, and even a Sikorsky tiltwing. Additional designs were submitted from Boeing Wichita (direct lift), Ling-Temco-Vought with its XC-142 tiltwing, Boeing Vertol's tiltwing, Mcdonnell's compound and tiltwing, and the Douglas turboduct and turboprop designs. A private party submitted a re-design of the Breguet 941 as a VTOL transport. It is important to document these 53 year-old designs to preserve a part of this country's aviation heritage.

  19. Computational analysis of aircraft pressure relief doors (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

  20. Scheduling of an aircraft fleet (United States)

    Paltrinieri, Massimo; Momigliano, Alberto; Torquati, Franco


    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.

  1. Dynamic decoupling nonlinear control method for aircraft gust alleviation (United States)

    Lv, Yang; Wan, Xiaopeng; Li, Aijun


    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.

  2. Control optimization, stabilization and computer algorithms for aircraft applications (United States)

    Athans, M. (Editor); Willsky, A. S. (Editor)


    The analysis and design of complex multivariable reliable control systems are considered. High performance and fault tolerant aircraft systems are the objectives. A preliminary feasibility study of the design of a lateral control system for a VTOL aircraft that is to land on a DD963 class destroyer under high sea state conditions is provided. Progress in the following areas is summarized: (1) VTOL control system design studies; (2) robust multivariable control system synthesis; (3) adaptive control systems; (4) failure detection algorithms; and (5) fault tolerant optimal control theory.

  3. Reduction environmental effects of civil aircraft through multi-objective flight plan optimisation (United States)

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


    With rising environmental alarm, the reduction of critical aircraft emissions including carbon dioxides (CO2) and nitrogen oxides (NOx) is one of most important aeronautical problems. There can be many possible attempts to solve such problem by designing new wing/aircraft shape, new efficient engine, etc. The paper rather provides a set of acceptable flight plans as a first step besides replacing current aircrafts. The paper investigates a green aircraft design optimisation in terms of aircraft range, mission fuel weight (CO2) and NOx using advanced Evolutionary Algorithms coupled to flight optimisation system software. Two multi-objective design optimisations are conducted to find the best set of flight plans for current aircrafts considering discretised altitude and Mach numbers without designing aircraft shape and engine types. The objectives of first optimisation are to maximise range of aircraft while minimising NOx with constant mission fuel weight. The second optimisation considers minimisation of mission fuel weight and NOx with fixed aircraft range. Numerical results show that the method is able to capture a set of useful trade-offs that reduce NOx and CO2 (minimum mission fuel weight).

  4. Analysis of Aircraft Control Performance using a Fuzzy Rule Base Representation of the Cooper-Harper Aircraft Handling Quality Rating (United States)

    Tseng, Chris; Gupta, Pramod; Schumann, Johann


    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

  5. Probabilistic Modeling of Aircraft Trajectories for Dynamic Separation Volumes (United States)

    Lewis, Timothy A.


    With a proliferation of new and unconventional vehicles and operations expected in the future, the ab initio airspace design will require new approaches to trajectory prediction for separation assurance and other air traffic management functions. This paper presents an approach to probabilistic modeling of the trajectory of an aircraft when its intent is unknown. The approach uses a set of feature functions to constrain a maximum entropy probability distribution based on a set of observed aircraft trajectories. This model can be used to sample new aircraft trajectories to form an ensemble reflecting the variability in an aircraft's intent. The model learning process ensures that the variability in this ensemble reflects the behavior observed in the original data set. Computational examples are presented.

  6. Design of Through-flow Nacelle for Low-speed Wind Tunnel Testing of Civil Aircraft%民机低速风洞试验通气发房设计

    Institute of Scientific and Technical Information of China (English)

    胡仞与; 张东云; 施永毅


    通气发房是民机风洞试验中模拟发动机效应的一种有效手段。通过调整通气发房出口面积,可以对通过发房的流量进行控制,实现所需模拟的流量系数,保证进气流场的几何相似性。失速特性是民机的一个重要的性能指标,大量的低速风洞试验工作都着眼于着落构型下失速特性的研究;而在失速特性的适航审定试飞时的发动机将处于慢车功率状态,因此以模拟慢车流量系数作为低速风洞试验通气发房的设计目标,有助于在风洞试验中对失速特性进行预测。慢车功率时,由于发动机风扇压比很小,如保留外涵喷口形状,通气发房还能近似模拟风扇的喷流效应。发动机在慢车功率下的流量系数在0.5附近,为实现这一流量系数,在设计通气发房时,需调整内涵出口面积,使发房的总出口面积接近唇口面积的一半。 CFD计算证明这种设计方法得到的通气发房基本能够实现预期的流量系数。%Through-flow nacelle ( TFN) is an effective method of simulating engine effect in wind tunnel Testing. By adjusting the nozzle exit areas of a TFN, the flow passing the TFN could be controlled and the flow ratio ( MFR) could be achieved to make sure the similarity around the inlet flow field. As stall characteristics is one of the impor-tant factor in defining civil aircraft performance, a great portion of the low speed wind tunnel tests is devoted to the study of the stall characteristics of aircraft in landing configuration;and due to the fact that engines tend to be set at an idle condition during airworthy flight tests for stall speed determination, designing a TFN with a MFR corre-sponding to an idle power setting is desirable for the prediction of stall characteristics in wind tunnel testing. When running at idle conditions, an engine will have a very low fan pressure ratio, which means if the fan nozzle geometry is maintained, TFN can

  7. Aircraft propeller control (United States)

    Day, Stanley G. (Inventor)


    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.

  8. Commercial Aircraft Protection

    Energy Technology Data Exchange (ETDEWEB)

    Ehst, David A. [Argonne National Lab. (ANL), Argonne, IL (United States)


    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.

  9. 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


    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.


    Directory of Open Access Journals (Sweden)



    Full Text Available A stress analysis software based on MATLAB, Graphic user interface (GUI has been developed. The developed software can be used to estimate load on a wing and to compute the stresses at any point along the span of the wing of a given aircraft. The generalized formulation allows performing stress analysis even for a multispar (multicell wing. The software is expected to be a useful tool for effective teaching learning process of courses on aircraft structures and aircraft structural design.





    A stress analysis software based on MATLAB, Graphic user interface (GUI) has been developed. The developed software can be used to estimate load on a wing and to compute the stresses at any point along the span of the wing of a given aircraft. The generalized formulation allows performing stress analysis even for a multispar (multicell) wing. The software is expected to be a useful tool for effective teaching learning process of courses on aircraft structures and aircraft structural design.

  12. An aircraft concept/preliminary design evaluation approach based on joint probability of success%基于联合成功率的飞机总体设计评价方法研究

    Institute of Scientific and Technical Information of China (English)

    李延杰; 刘晓东; 付雅芳


    为了提高设计决策的科学性和稳健性,对不确定因素影响下的飞机总体方案评价问题进行了研究,提出了一个以联合成功率为综合评价指标的决策方法.根据多变量概率理论,定义了联合成功率的数学表达式,研究了联合概率密度函数的计算方法:联合概率模型;依托联合概率分布,将概率设计方法和多准则决策方法进行有机结合,给出了基于联合成功率的飞机总体方案评价步骤.最后,通过算例分析,对该方法的实际应用进行了演示,并验证了联合概率模型的合理性.%In order to deal with the evaluation of aircraft conceptual/preliminary design impacted by a vast amount of uncertainty, then make the result of the design decision making more scientific and robust than traditional method,a new decision-making method which regards joint probability of success of the design as overall evaluation index was developed.According to multi-oariate probability theory,the mathe-matic formula of joint probability of success was presented,and a specific algorithm was introduced that compute the joint probability density function:Joint probability model.By the joint probability distribution function,traditional probabilistic method and multi梒riteria decision making technique were combined together,and the specific operation process of this new method was outlined.Finally,the application of this method in practice was demonstrated via an example,and the rationality of the joint probability density model was illustrated.

  13. A New Flexible Honeycomb Structure and Its Application in Structure Design of Morphing Aircraft%一种新的柔性蜂窝结构及其在变体飞机中的应用

    Institute of Scientific and Technical Information of China (English)

    张平; 周丽; 邱涛


    Morphing aircraft require the airfoil camber to change continuously and smoothly.The flexible skins must have substantial in-plane expansion deformability, while at the same time it must be able to bear the out-of-plane aerodynamic loads.In this article, a new flexible honeycomb structure is designed for the wing with a variable camber trailing edge.The relationship between the in-plane deformability and the shape parameters of the flexible honeycomb are studied.Simulation and experimental studies are carried out for the flexible honeycomb.The results show that the flexible honeycomb has substantial in-plane deformability and maintains good out-of-plane bearing capacity, which satisfies the application requirements of the wing with a variable camber trailing edge.%变体色机要求机翼结构可以光滑连续地变形.机翼的蒙皮要有足够大的面内伸缩变形能力,同时还要有足够的面外承载能力.本文针对后缘变弯度机翼,设计出一种新的柔性蜂窝结构.研究了该柔性蜂窝的面内变形能力和形状参数的关系.仿真分析和试验验证表明,该柔性蜂窝结构具有足够的面内变形能力,变形后仍保持良好的面外承载能力,满足后缘变弯度机翼的使用要求.

  14. Squeeze Film Damping for Aircraft Gas Turbines

    Directory of Open Access Journals (Sweden)

    R. W. Shende


    Full Text Available Modern aircraft gas turbine engines depend heavily on squeeze film damper supports at the bearings for abatement of vibrations caused by a number of probable excitation sources. This design ultimately results in light-weight construction together with higher efficiency and reliability of engines. Many investigations have been reported during past two decades concerning the functioning of the squeeze film damper, which is simple in construction yet complex in behaviour with its non-linearity and multiplicity of variables. These are reviewed in this article to throw light on the considerations involved in the design of rotor-bearing-casing systems incorporating squeeze film dampers.

  15. Composite Axial Flow Propulsor for Small Aircraft



    This work focuses on the design of an axial flow ducted fan driven by a reciprocating engine. The solution minimizes the turbulization of the flow around the aircraft. The fan has a rotor - stator configuration. Due to the need for low weight of the fan, a carbon/epoxy composite material was chosen for the blades and the driving shaft.The fan is designed for optimal isentropic efficiency and free vortex flow. A stress analysis of the rotor blade was performed using the Finite Element  Method....

  16. TRACON Aircraft Arrival Planning and Optimization Through Spatial Constraint Satisfaction (United States)

    Bergh, Christopher P.; Krzeczowski, Kenneth J.; Davis, Thomas J.; Denery, Dallas G. (Technical Monitor)


    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.

  17. A Parametrical Transport Aircraft Fuselage Model for Preliminary Sizing and Beyond


    Schwinn, Dominik; Kohlgrüber, Dieter; Scherer, Julian; Siemann, Martin


    Aircraft design generally comprises three consecutive phases: Conceptual, preliminary and detailed design phase. The preliminary design phase is of particular interest as the basic layout of the primary structure is defined. Up to date, semi-analytical methods are widely used in this design stage to estimate the structural mass. Although these methods lead to adequate results for the major aircraft components of standard configurations, the evaluation of new configurations (e.g. box wing, ble...

  18. Project ADIOS: Aircraft Deployable Ice Observation System (United States)

    Gudmundsson, G. H.


    Regions of the Antarctic that are of scientific interest are often too heavily crevassed to enable a plane to land, or permit safe access from a field camp. We have developed an alternative strategy for instrumenting these regions: a sensor that can be dropped from an overflying aircraft. Existing aircraft deployable sensors are not suitable for long term operations in areas where snow accumulates, as they are quickly buried. We have overcome this problem by shaping the sensor like an aerodynamic mast with fins and a small parachute. After being released from the aircraft, the sensor accelerates to 42m/s and stabilizes during a 10s descent. On impact with the snow surface the sensor package buries itself to a depth of 1m then uses the large surface area of the fins to stop it burying further. This leaves a 1.5m mast protruding high above the snow surface to ensure a long operating life. The high impact kinetic energy and robust fin braking mechanism ensure that the design works in both soft and hard snow. Over the past two years we have developed and tested our design with a series of aircraft and wind tunnel tests. Last season we used this deployment strategy to successfully install a network of 31 single band GPS sensors in regions where crevassing has previously prevented science operations: Pine Island Glacier, West Antarctica, and Scar Inlet, Antarctic Peninsula. This season we intend to expand on this network by deploying a further 25 single and dual band GPS sensors on Thwaites Glacier, West Antarctica.


    Directory of Open Access Journals (Sweden)

    C.M. Meyer


    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.

  20. Aircraft landing using GPS (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.

  1. Examining the Relationship Between Passenger Airline Aircraft Maintenance Outsourcing and Aircraft Safety (United States)

    Monaghan, Kari L.

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

  2. Design and characteristic research of double-acting aircraft deicing fluid pump%双作用式飞机除冰液泵设计及特性研究

    Institute of Scientific and Technical Information of China (English)

    龚淼; 邢志伟; 王立文


    除冰液的加注速度是影响机场除冰作业效率的重要因素。设计了一种面向飞机除冰装备领域的双作用式大流量往复泵,给出了设计原理、主要部件设计计算书及总体设计图。通过建模仿真分析双作用泵的压力流量特性;通过改变活塞间隙的仿真实验得到系统阻尼和流量输出的折中优化方案,并依据仿真得到的最佳参数进行实验,验证仿真分析的合理性。结果表明:根据除冰液的粘度,活塞间隙在3 mm条件下,系统阻尼、流量、脉动到达最优关联,流量输出平稳,验证了设计方案的合理性和可行性。泵在工况压力范围内,输出流量和脉动抑制均达到预期效果,性能超越现有同类除冰加液设备性能,为行业应用和相关设备的设计提供参考。%Fil ing speed of deicing fluid is an important factor that affects the efficiency of airport deicing operation.In this paper,we design a double-acting large flow reciprocating pump for air-craft deicing equipment.We demonstrate the principle,the design drawing and the design calcu-lation of key components.The pressure-flow characteristics of double-acting pump are analyzed through modeling and simulation methods;the optimal program of system damping and flow out-put are obtained by the simulation experiment of changing piston clearance.We implement a practical experimental analysis,which is based on the optimal parameters obtained from the sim-ulation,to test the rationality of the simulation experiment.The result is shown that,according to the viscosity of the deicing fluid,the system damping,flow and pulsation are optimal relevance and the flow steady output when the piston clearance is 3mm.This verifies the rationality and fea-sibility of the design.Within the operating pressure range of the pump,the output flow and ripple suppression achieve the desired effect,and the performance is better than the existing similar de

  3. NDO based anti-disturbance control law design for aircraft trajectory tracking%基于 NDO 的飞机轨迹跟踪抗干扰控制律设计

    Institute of Scientific and Technical Information of China (English)

    苏磊; 姚宏; 杜军


    A robust sliding mode control law of trajectory tracking is described and demonstrated for the coupled and under-actuated aircraft longitudinal dynamic model.Firstly,by introducing a virtual state variable, the state counterchange is applied to realize the control decoupling.Secondly,a nonlinear disturbance observer (NDO)is proposed for the compensation of system uncertainty which consists of modeling error and atmosphere disturbance.Thirdly,the curves of angle of attack (AOA)and the virtual state variable during extremely short takeoff and landing (ESTOL)are set up,which are treated as the tracking trajectories of the designed sliding mode control law.Finally,the simulation results are given,which demonstrates that the proposed NDO can re-alize accurate estimation and compensation of system uncertainty,as well as that the designed control law can be effectively applied to longitudinal trajectory tracking of AOA against system modeling error and atmosphere dis-turbance.%针对飞机纵向欠驱动耦合动力学模型设计鲁棒轨迹跟踪滑模控制律。首先,通过引入虚拟状态变量进行状态变换实现模型控制解耦。其次,考虑由系统建模误差和大气干扰组成的复合不确定性,设计非线性干扰观测器(nonlinear disturbance observer,NDO)进行观测补偿。然后,建立飞机极短距起降中攻角变化轨迹曲线,设计滑模控制律实现对虚拟状态变量和攻角轨迹指令的稳定跟踪。仿真结果表明,NDO 可以实现对系统不确定性的精确观测和补偿,滑模控制律具有对系统建模误差和大气风切变的鲁棒性和抗干扰性。

  4. Sonic Fatigue Design Guide for Military Aircraft (United States)


    the norma ii ,d ý,Iwctra I den-, ity in (1`/rn2 ) /H.’ , relative to I N/rn 2 over-all SPL, is read from the ordinate of Figure 4.2 .2 -5 and is then...presented at the AIAA/NASA/ ASTM /IES Seventh Space Simu- At ion Cunfererce, Los Angeles, Calif., November 12-14, 1973. Rucker, C. E., and Grandle, R. E...Government Printing Office, September, 197T 5. Anon.; A Guide for Fatigue Testin2 and the Statistical Analysis of Fati ue Data, ASTM Special Technical

  5. System Design for Transitional Aircraft Support

    Directory of Open Access Journals (Sweden)

    John P.T. Mo


    Full Text Available The Australian Defence Force and industry are undergoing significant changes in the way they work together in capability enhancement programs. There are capability gaps in maintaining and supporting current obligations during major asset acquisition, which has migrated into the front line of Royal Air Force Fighter Groups as a new capability. This paper examines a steady state support solution and argues that in order to interchange from one support solution to a new architecture there must be a period for transition, which may need its own interim business model and operational service. A preliminary study of several existing support solutions reveals the generic elements that need to be parameterized and traced through the support system architecture trajectory.

  6. High Voltage Design Guide. Volume IV. Aircraft (United States)


    by the reaction of urea with formaldehyde. An amino resin. Urethane. See Isocyanate Resins. Vinyl Resin. A synthetic resin formed by the polymerization...oxidation reactions are sludge, asphalt , a:ids, organic esters, soaps, and oxides. Oil color, as an index of the degree of refineme.. for unused oils...Materials Alkyd resins Acrylic plastics Cellulose esters Asphalt Cork Chloride flux Epoxy resins Copper (bare) Masonite Fiber board Melamine resins Greases

  7. Propfan test assessment testbed aircraft flutter model test report (United States)

    Jenness, C. M. J.


    The PropFan Test Assessment (PTA) program includes flight tests of a propfan power plant mounted on the left wind of a modified Gulfstream II testbed aircraft. A static balance boom is mounted on the right wing tip for lateral balance. Flutter analyses indicate that these installations reduce the wing flutter stabilizing speed and that torsional stiffening and the installation of a flutter stabilizing tip boom are required on the left wing for adequate flutter safety margins. Wind tunnel tests of a 1/9th scale high speed flutter model of the testbed aircraft were conducted. The test program included the design, fabrication, and testing of the flutter model and the correlation of the flutter test data with analysis results. Excellent correlations with the test data were achieved in posttest flutter analysis using actual model properties. It was concluded that the flutter analysis method used was capable of accurate flutter predictions for both the (symmetric) twin propfan configuration and the (unsymmetric) single propfan configuration. The flutter analysis also revealed that the differences between the tested model configurations and the current aircraft design caused the (scaled) model flutter speed to be significantly higher than that of the aircraft, at least for the single propfan configuration without a flutter boom. Verification of the aircraft final design should, therefore, be based on flutter predictions made with the test validated analysis methods.

  8. A NASA study of the impact of technology on future carrier based tactical aircraft - Overview (United States)

    Wilson, S. B., III


    This paper examines the impact of technology on future carrier based tactical aircraft. The results were used in the Center for Naval Analysis Future Carrier Study. The NASA Team designed three classes of aircraft ('Fighter', 'Attack', and 'Multimission') with two different technology levels. The Multimission aircraft were further analyzed by examining the penalty on the aircraft for both catapult launch/arrested landing recovery (Cat/trap) and short take-off/vertical landing (STOVL). The study showed the so-called STOVL penalty was reduced by engine technology and the next generation Strike Fighter will pay more penalty for Cat/trap than for STOVL capability.

  9. Dynamics and Adaptive Control for Stability Recovery of Damaged Aircraft (United States)

    Nguyen, Nhan; Krishnakumar, Kalmanje; Kaneshige, John; Nespeca, Pascal


    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.

  10. Active Structural Control for Aircraft Efficiency with the X-56A Aircraft (United States)

    Ouellette, Jeffrey


    The X-56A Multi-Utility Technology Testbed is an experimental aircraft designed to study active control of flexible structures. The vehicle is easily reconfigured to allow for testing of different configurations. The vehicle is being used to study new sensor, actuator, modeling and controls technologies. These new technologies will allow for lighter vehicles and new configurations that exceed the efficiency currently achievable. A description of the vehicle and the current research efforts that it enables are presented.

  11. Commercial aircraft composite technology

    CERN Document Server

    Breuer, Ulf Paul


    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,...

  12. Aircraft control system (United States)

    Lisoski, Derek L. (Inventor); Kendall, Greg T. (Inventor)


    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.

  13. Information note about the protection of nuclear facilities against aircraft crashes; Note d'information sur la protection des installations nucleaires contre les chutes d'avions

    Energy Technology Data Exchange (ETDEWEB)



    The protection of nuclear facilities against external risks (earthquakes, floods, fires etc..) is an aspect of safety taken into consideration by the French authority of nuclear safety (ASN). Concerning the aircraft crashes, the fundamental safety rules make three categories of aircraft: the small civil aircraft (weight < 5.7 t), the military aircraft, and the commercial aircraft (w > 5.7 t). Nuclear facilities are designed to resist against crashes of aircraft from the first category only, because the probability of the accidental crash of a big aircraft are extremely low. This document comprises an information note about the protection of nuclear facilities against aircraft crashes, a dossier about the safety of nuclear facilities with respect to external risks in general (natural disasters and aircraft crashes), and an article about the protection of nuclear power plants against aircraft crashes (design, safety measures, regulation, surveillance, experience feedback). (J.S.)

  14. Aircraft recognition and pose estimation (United States)

    Hmam, Hatem; Kim, Jijoong


    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.

  15. Aerodynamic Optimization Design for Large Upswept Afterbody of Transport Aircraft Based on FFD Technology%基于FFD技术的大型运输机上翘后体气动优化设计

    Institute of Scientific and Technical Information of China (English)

    王元元; 张彬乾; 郭兆电; 董强


    利用非均匀有理B样条(NURBS)基函数属性建立了任意空间的自由变形(FFD)参数化方法,进一步结合无限插值(TFI)变形网格技术、二阶振荡粒子群优化(PSO)算法以及计算流体力学(CFD)数值模拟技术,构建了通用的气动外形优化设计系统.采用该系统对C17运输机上翘后体进行气动优化设计,在满足后体最大宽度、高度以及上翘角不减小的情况下,巡航状态减阻2.6%,压差阻力减小19.8%.流态分析显示,优化后体阻力减小的主要原因是后体截面近圆度的增加以及近圆度沿机身轴线的变化量的减小使得后体周向逆压梯度减小所致.研究结果表明本文建立的基于FFD技术的气动优化设计系统对于大型运输机上翘后体的气动优化设计具有较好的实用性.%A free-form deformation parameterization (FFD) method is established based on non-uniform rational B-spline (NURBS) basis function.Furthermore,by coupling the transfinite interpolation (TFI) grid deformation technology and computational fluid dynamics (CFD) method with improved particle swarm optimization (PSO) arithmetic,a general aerodynamic optimization design system is constructed.Then,the aerodynamic optimization design system is applied to designing a large upswept afterbody of transport aircraft C17 on the restrictions of nondecreasing maximum structure height,width and upswept angle.The optimized afterbody decreases the total drag by 2.6% and pressure drag by 19.8% respectively.A comparison analysis of the aerodynamic shape and flow pattern reveals that the key factors for the optimized afterbody to decrease the pressure drag greatly are the increased near-roundness of the afterbody cross-section and decreased near-roundness change ratio along the fuselage axis.The two factors enable the adverse pressure gradient along the circumferential direction to become smaller,which can suspend aferbody separation and weaken afterbody vortex strength

  16. 40 CFR 87.6 - Aircraft safety. (United States)


    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Aircraft safety. 87.6 Section 87.6 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF AIR POLLUTION FROM AIRCRAFT AND AIRCRAFT ENGINES General Provisions § 87.6 Aircraft safety. The provisions...

  17. 14 CFR 21.6 - Manufacture of new aircraft, aircraft engines, and propellers. (United States)


    ... Manufacture of new aircraft, aircraft engines, and propellers. (a) Except as specified in paragraphs (b) and (c) of this section, no person may manufacture a new aircraft, aircraft engine, or propeller based on... provisions of §§ 21.183(c), 21.184(b), or 21.185(c); and (2) New aircraft engines or propellers...

  18. 78 FR 54385 - Airworthiness Directives; Various Aircraft Equipped With Rotax Aircraft Engines 912 A Series Engine (United States)


    ... Aircraft Equipped With Rotax Aircraft Engines 912 A Series Engine AGENCY: Federal Aviation Administration... directive (AD) for various aircraft equipped with Rotax Aircraft Engines 912 A Series Engine. This AD...; phone: +43 7246 601 0; fax: +43 7246 601 9130; Internet: . You...

  19. Application of variable-sweep wings to commuter aircraft (United States)

    Robins, A. W.; Beissner, F. L., Jr.; Lovell, W. A.; Price, J. E.; Turriiziani, R. V.; Washburn, F. F.


    The effects of using variable-sweep wings on the riding quality and mission-performance characteristics of commuter-type aircraft were studied. A fixed-wing baseline vehicle and a variable-sweep version of the baseline were designed and evaluated. Both vehicles were twin-turboprop, pressurized-cabin, 30-passenger commuter aircraft with identical mission requirements. Mission performance was calculated with and without various ride-quality constraints for several combinations of cruise altitude and stage lengths. The variable-sweep aircraft had a gross weight of almost four percent greater than the fixed-wing baseline in order to meet the design-mission requirements. In smooth air, the variable sweep configuration flying with low sweep had a two to three percent fuel-use penalty. However, the imposition of quality constraints in rough air can result in advantages in both fuel economy and flight time for the variable-sweep vehicle flying with high sweep.

  20. Research on Multi-objective Optimal Parameters Design of Aircraft Flight Control System%飞机飞行控制系统参数多目标优化设计研究

    Institute of Scientific and Technical Information of China (English)

    白俊杰; 张坤; 崔彦勇


    In the traditional optimization design of flight control system (FCS),there are some disadvanta-ges such as weak correlation between the single object and the flight quality requirements , ambiguous physical meaning and difficulty of using single object to optimize many objects at the same time .To solve such problem ,an improved particle swarm optimization ( PSO) algorithm was proposed .By simulating the foraging aggregation behavior of birds ,the particles can be divided into several dynamic sub-swarms with respect to the finding and expanding of forage in the improved PSO algorithm .So that ,the diversity of par-ticles can be maintained by this method , thus can restrain local optimum phenomena .Finally , using the improved PSO algorithm for numerical simulation of a certain type of aircraft longitudinal control law ,the results show that the proposed algorithm can effectively improve the efficiency of the FCS parameters tun-ing,and the results can meet the flight qualities requirements .%针对传统飞行控制律参数单目标优化设计不能同时满足多控制指标要求,且与飞行品质要求缺乏相关性,物理意义不明确等缺点,提出了一种基于改进粒子群算法的飞行控制律多目标优化设计方法。算法模拟鸟类捕食过程,使得种群随着“食物”的发现和消耗,聚集为数量和构成动态调整多个子群,且子群粒子速度也随之进行自适应变异,从而有利于维持种群的多样性,有效抑制早熟收敛现象发生。最后,使用改进的粒子群优化算法对某型飞机纵向控制律设计进行数值仿真,结果显示,算法有效提高控制律优化调参效率,结果满足期望的飞行品质要求。

  1. Mission Analysis and Aircraft Sizing of a Hybrid-Electric Regional Aircraft (United States)

    Antcliff, Kevin R.; Guynn, Mark D.; Marien, Ty V.; Wells, Douglas P.; Schneider, Steven J.; Tong, Michael T.


    The purpose of this study was to explore advanced airframe and propulsion technologies for a small regional transport aircraft concept (approximately 50 passengers), with the goal of creating a conceptual design that delivers significant cost and performance advantages over current aircraft in that class. In turn, this could encourage airlines to open up new markets, reestablish service at smaller airports, and increase mobility and connectivity for all passengers. To meet these study goals, hybrid-electric propulsion was analyzed as the primary enabling technology. The advanced regional aircraft is analyzed with four levels of electrification, 0 percent electric with 100 percent conventional, 25 percent electric with 75 percent conventional, 50 percent electric with 50 percent conventional, and 75 percent electric with 25 percent conventional for comparison purposes. Engine models were developed to represent projected future turboprop engine performance with advanced technology and estimates of the engine weights and flowpath dimensions were developed. A low-order multi-disciplinary optimization (MDO) environment was created that could capture the unique features of parallel hybrid-electric aircraft. It is determined that at the size and range of the advanced turboprop: The battery specific energy must be 750 watt-hours per kilogram or greater for the total energy to be less than for a conventional aircraft. A hybrid vehicle would likely not be economically feasible with a battery specific energy of 500 or 750 watt-hours per kilogram based on the higher gross weight, operating empty weight, and energy costs compared to a conventional turboprop. The battery specific energy would need to reach 1000 watt-hours per kilogram by 2030 to make the electrification of its propulsion an economically feasible option. A shorter range and/or an altered propulsion-airframe integration could provide more favorable results.

  2. Current and Future Research in Active Control of Lightweight, Flexible Structures Using the X-56 Aircraft (United States)

    Ryan, John J.; Bosworth, John T.; Burken, John J.; Suh, Peter M.


    The X-56 Multi-Utility Technology Testbed aircraft system is a versatile experimental research flight platform. The system was primarily designed to investigate active control of lightweight flexible structures, but is reconfigurable and capable of hosting a wide breadth of research. Current research includes flight experimentation of a Lockheed Martin designed active control flutter suppression system. Future research plans continue experimentation with alternative control systems, explore the use of novel sensor systems, and experiments with the use of novel control effectors. This paper describes the aircraft system, current research efforts designed around the system, and future planned research efforts that will be hosted on the aircraft system.

  3. VTOL to Transonic Aircraft Project (United States)

    National Aeronautics and Space Administration — The cyclogyro, an aircraft propulsion concept with the potential for VTOL to the lower bounds of transonic flight, is conceptually simple but structurally and...

  4. Western Pacific Typhoon Aircraft Fixes (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Western Pacific typhoon aircraft reconnaissance data from the years 1946 - 1965 and 1978, excluding 1952, were transcribed from original documents, or copy of...

  5. Fire resistant aircraft seat program (United States)

    Fewell, L. A.


    Foams, textiles, and thermoformable plastics were tested to determine which materials were fire retardant, and safe for aircraft passenger seats. Seat components investigated were the decorative fabric cover, slip covers, fire blocking layer, cushion reinforcement, and the cushioning layer.

  6. Causes of aircraft electrical failures (United States)

    Galler, Donald; Slenski, George


    The results of a survey of data on failures of aircraft electronic and electrical components that was conducted to identify problematic components are reported. The motivation for the work was to determine priorities for future work on the development of accident investigation techniques for aircraft electrical components. The primary source of data was the Airforce Mishap Database, which is maintained by the Directorate of Aerospace Safety at Norton Air Force Base. Published data from the Air Force Avionics Integrity Program (AVIP) and Hughes Aircraft were also reviewed. Statistical data from these three sources are presented. Two major conclusions are that problems with interconnections are major contributors to aircraft electrical equipment failures, and that environmental factors, especially corrosion, are significant contributors to connector problems.

  7. Aircraft Simulator Data Requirements Study. Volume II (United States)


    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

  8. Portable catapult launcher for small aircraft (United States)

    Rosenbaum, Bernard J. (Inventor); Petter, George E. (Inventor); Gessler, Joseph A. (Inventor); Hughes, Michael G. (Inventor)


    An apparatus for launching an aircraft having a multiplicity of interconnected elongated tracks of rigid material forming a track system and wherein each elongated track has a predetermined elongated track cross-sectional design, a winch system connected to the track system wherein the winch system has a variable mechanical advantage, one or more elongated elastic members wherein one end of each of the one or more elongated elastic members is adjustably connected to the track system, and a carrier slidably mounted to the track system wherein the carrier is connected to the winch system and to the other end of each of the one or more elongated elastic members.

  9. The Glass Ceiling for Remotely Piloted Aircraft (United States)


    Views July–August 2013 Air & Space Power Journal | 101 The Glass Ceiling for Remotely Piloted Aircraft Lt Col Lawrence Spinetta, PhD, USAF Those...number. 1. REPORT DATE AUG 2013 2. REPORT TYPE 3. DATES COVERED 00-00-2013 to 00-00-2013 4. TITLE AND SUBTITLE The Glass Ceiling for Remotely...promotion to flag rank. By design or effect, a bottleneck exists that guarantees a glass ceiling (i.e., a barrier to advancement) for RPA officers. This

  10. Validation Effectiveness of Develop Maintainability Allocation on Aircraft Mechanical Components

    Directory of Open Access Journals (Sweden)

    Wan Husain W.M.S.


    Full Text Available Maintainability Allocation is a process to identify the allowable maximum task time for each individual component. Consequently, this provides clear pictures to the designers to design and identify potential design improvement within allowable maintenance allocation time limits. During the design process elements such as missteps or misapplications most commonly occur. Here, the authors propose having the maximum target for each individual maintainability component. The main objective of this paper is to present the validation process of developed Maintainability Allocation to potentially eliminate previous problems. The process of validation begins with analysed all the data collected from Service Difficulty Reports (SDR for selected aircraft. This is to understand the problems from existing aircraft before a new design is proposed through the process of Maintainability Allocation prediction. The validation processes have discovered the importance of utilising historical information such as feedback information. The second area is looking at the element of quantifying the data collected from aircraft feedback information which contains various types of information that could be used for future improvement. Validation process shows that feedback information has helped to identify the critical and sensitive components that need more attention for further improvement. The study shows that the aircraft maintenance related feedback information systems analyses were very useful for deciding maintainability effectiveness; these include planning, organising maintenance and design improvement. There is no doubt that feedback information has the ability to contribute an important role in design activities. The results also show that maintainability is an important measure that can be used as a guideline for managing efforts made for the improvement of aircraft components.

  11. Aircraft vulnerability modeling and computation methods based on product structure and CATIA

    Institute of Scientific and Technical Information of China (English)

    Li Jun; Yang Wei; Zhang Yugang; Pei Yang; Ren Yunsong; Wang Wei


    Survivability strengthening/vulnerability reduction designs have become one of the most important design disciplines of military aircraft now.Due to progressiveness and complexity of modern combat aircraft,the existing vulnerability modeling and computation methods cannot meet the current engineering application requirements.Therefore,a vulnerability modeling and computation method based on product structure and CATIA is proposed in sufficient consideration of the design characteristics of modern combat aircraft.This method directly constructs the aircraft vulnerability model by CATIA or the digital model database,and manages all the product components of the vulnerability model via aircraft product structure.Using CAA second development,the detailed operations and computation methods of vulnerability analysis are integrated into CATIA software environment.Comprehensive assessment data and visual kill probability Iso-contours can also be presented,which meet the vulnerability analysis requirements of modern combat aircraft effectively.The intact vulnerability model of one hypothetical aircraft is constructed,and the effects of redundant technology to the aircraft vulnerability are assessed,which validate the engineering practicality of the method.

  12. Structural Dynamics of Maneuvering Aircraft. (United States)



  13. Acoustic measurements of F-16 aircraft operating in hush house, NSN 4920-02-070-2721 (United States)

    Miller, V. R.; Plzak, G. A.; Chinn, J. M.


    The purpose of this test program was to measure the acoustic environment in the hush house facility located at Kelly Air Force Base, Texas, during operation of the F-16 aircraft to ensure that aircraft structural acoustic design limits were not exceeded. The acoustic measurements showed that no sonic fatigue problems are anticipated with the F-16 aircraft aft fuselage structure during operation in the hush house. The measured acoustic levels were less than those measured in an F-16 aircraft water cooled hush house at Hill AFB, but were increased over that measured during ground run up. It was recommended that the acoustic loads measured in this program should be specified in the structural design criteria for aircraft which will be subjected to hush house operation or defining requirements for associated equipment.

  14. Aircraft exhaust sulfur emissions

    Energy Technology Data Exchange (ETDEWEB)

    Brown, R.C.; Anderson, M.R.; Miake-Lye, R.C.; Kolb, C.E. [Aerodyne Research, Inc., Billerica, MA (United States). Center for Chemical and Environmental Physics; Sorokin, A.A.; Buriko, Y.I. [Scientific Research Center `Ecolen`, Moscow (Russian Federation)


    The extent to which fuel sulfur is converted to SO{sub 3} during combustion and the subsequent turbine flow in supersonic and subsonic aircraft engines is estimated numerically. The analysis is based on: a flamelet model with non-equilibrium sulfur chemistry for the combustor, and a one-dimensional, two-stream model with finite rate chemical kinetics for the turbine. The results indicate that between 2% and 10% of the fuel sulfur is emitted as SO{sub 3}. It is also shown that, for a high fuel sulfur mass loading, conversion in the turbine is limited by the level of atomic oxygen at the combustor exit, leading to higher SO{sub 2} oxidation efficiency at lower fuel sulfur loadings. While SO{sub 2} and SO{sub 3} are the primary oxidation products, the model results further indicate H{sub 2}SO{sub 4} levels on the order of 0.1 ppm for supersonic expansions through a divergent nozzle. This source of fully oxidized S(6) (SO{sub 3} + H{sub 2}SO{sub 4}) exceeds previously calculated S(6) levels due to oxidation of SO{sub 2} by OH in the exhaust plume outside the engine nozzle. (author) 26 refs.

  15. Parabolic aircraft solidification experiments (United States)

    Workman, Gary L. (Principal Investigator); Smith, Guy A.; OBrien, Susan


    A number of solidification experiments have been utilized throughout the Materials Processing in Space Program to provide an experimental environment which minimizes variables in solidification experiments. Two techniques of interest are directional solidification and isothermal casting. Because of the wide-spread use of these experimental techniques in space-based research, several MSAD experiments have been manifested for space flight. In addition to the microstructural analysis for interpretation of the experimental results from previous work with parabolic flights, it has become apparent that a better understanding of the phenomena occurring during solidification can be better understood if direct visualization of the solidification interface were possible. Our university has performed in several experimental studies such as this in recent years. The most recent was in visualizing the effect of convective flow phenomena on the KC-135 and prior to that were several successive contracts to perform directional solidification and isothermal casting experiments on the KC-135. Included in this work was the modification and utilization of the Convective Flow Analyzer (CFA), the Aircraft Isothermal Casting Furnace (ICF), and the Three-Zone Directional Solidification Furnace. These studies have contributed heavily to the mission of the Microgravity Science and Applications' Materials Science Program.

  16. 大涵道比宽体客机发动机方案设计及系列化发展研究%The Performance Design and Series Development Strategy Study of High Bypass Ratio Wide-body Aircraft Engines

    Institute of Scientific and Technical Information of China (English)

    薛冰晶; 齐小龙; 周淼


    基于宽体客机航空发动机系列化发展进行了总体性能方案设计,并分别基于保持整机不变和保持核心机不变的原则,对推力系列化发展方案进行了分析。结果表明,对于减推力使用发动机而言,可以直接采用降低高低压轴转速的方式;对于推力增长发动机而言,需重新匹配低压系统以得到更优化的方案。%Series development strategy is of great importance in wide-body aircraft engine design. To gain the in-sight into this domain, a number of wide-body aircraft engine performance designs based on a sequence of thrust requirements will be developed and studied in this paper. All design works are subject to one constraint which is re-maining core engine unchanged or remaining entire engine unchanged. The result shows that once the baseline en-gine is defined, remaining entire engine unchanged with reduced rotating speed brings more benefits to deliver low-er thrust level, while thrust growth would be readily obtained by re-matching low pressure system with the same core engine.

  17. Global Local Structural Optimization of Transportation Aircraft Wings

    NARCIS (Netherlands)

    Ciampa, P.D.; Nagel, B.; Van Tooren, M.J.L.


    The study presents a multilevel optimization methodology for the preliminary structural design of transportation aircraft wings. A global level is defined by taking into account the primary wing structural components (i.e., ribs, spars and skin) which are explicitly modeled by shell layered finite e

  18. Aeroservoelastic model based active control for large civil aircraft

    Institute of Scientific and Technical Information of China (English)


    A modeling and control approach for an advanced configured large civil aircraft with aeroservoelasticity via the LQG method and control allocation is presented.Mathematical models and implementation issues for the multi-input/multi-output(MIMO) aeroservoelastic system simulation developed for a flexible wing with multi control surfaces are described.A fuzzy logic based optimization approach is employed to solve the constrained control allocation problem via intelligently adjusting the components of output vector and find a proper vector in the attainable moment set(AMS) autonomously.The basic idea is to minimize the L2 norm of error between the desired moment and achievable moment using the designing freedom provided by redundantly allocated actuators and control surfaces.Considering the constraints of control surfaces,in order to obtain acceptable performance of aircraft such as stability and maneuverability,the fuzzy weights are updated by the learning algorithm,which makes the closed-loop system self-adaptation.Finally,an application example of flight control designing for the advanced civil aircraft is discussed as a demonstration.The studies we have performed showed that the advanced configured large civil aircraft has good performance with the proper designed control law designed via the proposed approach.The gust alleviation and flutter suppression are applied with the synergetic effects of elevator,ailerons,equivalent rudders and flaps.The results show good closed loop performance and meet the requirement of constraint of control surfaces.

  19. The ahead project: Advanced hybrid engines for aircraft development

    NARCIS (Netherlands)

    Rao, A.G.; Yin, F.


    Aviation is an ever-increasing market and more passengers and cargo are carried each year. The world is becoming ever more connected. However, this does come at a price: aviation has a marked in!uence on the environment. If aviation is to thrive in the future, breakthroughs in aircraft design and pr

  20. Frequency Analysis of Aircraft hazards for License Application

    Energy Technology Data Exchange (ETDEWEB)

    K. Ashley


    The preclosure safety analysis for the monitored geologic repository at Yucca Mountain must consider the hazard that aircraft may pose to surface structures. Relevant surface structures are located beneath the restricted airspace of the Nevada Test Site (NTS) on the eastern slope of Yucca Mountain, near the North Portal of the Exploratory Studies Facility Tunnel (Figure 1). The North Portal is located several miles from the Nevada Test and Training Range (NTTR), which is used extensively by the U.S. Air Force (USAF) for training and test flights (Figure 1). The NTS airspace, which is controlled by the U.S. Department of Energy (DOE) for NTS activities, is not part of the NTTR. Agreements with the DOE allow USAF aircraft specific use of the airspace above the NTS (Reference 2.1.1 [DIRS 103472], Section 3.1.1 and Appendix A, Section 2.1; and Reference 2.1.2 [DIRS 157987], Sections 1.26 through 1.29). Commercial, military, and general aviation aircraft fly within several miles to the southwest of the repository site in the Beatty Corridor, which is a broad air corridor that runs approximately parallel to U.S. Highway 95 and the Nevada-California border (Figure 2). These aircraft and other aircraft operations are identified and described in ''Identification of Aircraft Hazards'' (Reference 2.1.3, Sections 6 and 8). The purpose of this analysis is to estimate crash frequencies for aircraft hazards identified for detailed analysis in ''Identification of Aircraft Hazards'' (Reference 2.1.3, Section 8). Reference 2.1.3, Section 8, also identifies a potential hazard associated with electronic jamming, which will be addressed in this analysis. This analysis will address only the repository and not the transportation routes to the site. The analysis is intended to provide the basis for: (1) Categorizing event sequences related to aircraft hazards; (2) Identifying design or operational requirements related to aircraft hazards.