WorldWideScience

Sample records for aircraft design

  1. Aircraft Design

    Science.gov (United States)

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

    2016-01-01

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

  2. Designing A Conventional Aircraft

    OpenAIRE

    Sonei, Arash

    2014-01-01

    This paper is explaining the important design phases of dimensioning an unmanned conventional aircraft from scratch and will also design one according to a few chosen requirements. The design phases discussed will be all from wing dimensioning to stability and spin recovery, aircraft performance requirements and how to select a motor which overcomes these. As well as the optimal rate of climb for improved efficiency is discussed. In the end an aircraft which manages the set requirements and i...

  3. SOLAR AIRCRAFT DESIGN

    OpenAIRE

    RAHMATI, Sadegh; GHASED, Amir

    2015-01-01

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

  4. Innovations in Aircraft Design

    Science.gov (United States)

    1997-01-01

    The Boeing 777 carries with it basic and applied research, technology, and aerodynamic knowledge honed at several NASA field centers. Several Langley Research Center innovations instrumental to the development of the aircraft include knowledge of how to reduce engine and other noise for passengers and terminal residents, increased use of lightweight aerospace composite structures for increased fuel efficiency and range, and wind tunnel tests confirming the structural integrity of 777 wing-airframe integration. Test results from Marshall Space Flight Center aimed at improving the performance of the Space Shuttle engines led to improvements in the airplane's new, more efficient jet engines. Finally, fostered by Ames Research Center, the Boeing 777 blankets that protect areas of the plane from high temperatures and fire have a lineage to Advanced Flexible Reusable Surface Insulation used on certain areas of the Space Shuttle. According to Boeing Company estimates, the 777 has captured three-quarters of new orders for airplanes in its class since the program was launched.

  5. Challenges of aircraft design integration

    OpenAIRE

    Kafyeke, F.; Abdo, M.; Pepin, F; Piperni, P.; Laurendeau, E.

    2007-01-01

    The design of a modern airplane brings together many disciplines: structures, aerodynamics, controls, systems, propulsion with complex interdependencies and many variables. Recent aircraft programs, such as Bombardier's Continental Jet program use participants located around the world and selected for their cost, quality and delivery capability. These participants share the risk on the program and must therefore be fully implicated in the design. A big challenge is to provide information on c...

  6. Stochastic Methods for Aircraft Design

    Science.gov (United States)

    Pelz, Richard B.; Ogot, Madara

    1998-01-01

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

  7. Aircraft wing structure detail design

    Science.gov (United States)

    Sager, Garrett L.; Roberts, Ron; Mallon, Bob; Alameri, Mohamed; Steinbach, Bill

    1993-01-01

    The provisions of this project call for the design of the structure of the wing and carry-through structure for the Viper primary trainer, which is to be certified as a utility category trainer under FAR part 23. The specific items to be designed in this statement of work were Front Spar, Rear Spar, Aileron Structure, Wing Skin, and Fuselage Carry-through Structure. In the design of these parts, provisions for the fuel system, electrical system, and control routing were required. Also, the total weight of the entire wing planform could not exceed 216 lbs. Since this aircraft is to be used as a primary trainer, and the SOW requires a useful life of 107 cycles, it was decided that all of the principle stresses in the structural members would be kept below 10 ksi. The only drawback to this approach is a weight penalty.

  8. Alloy design for aircraft engines

    Science.gov (United States)

    Pollock, Tresa M.

    2016-08-01

    Metallic materials are fundamental to advanced aircraft engines. While perceived as mature, emerging computational, experimental and processing innovations are expanding the scope for discovery and implementation of new metallic materials for future generations of advanced propulsion systems.

  9. Engineering students win NASA aircraft design competition

    OpenAIRE

    Crumbley, Liz

    2004-01-01

    Centuria," a single-engine jet aircraft designed by undergraduate engineering students from Virginia Tech and their counterparts at Loughborough University in the U.K., has won the Best Overall Award in NASA's 2004 Revolutionary Vehicles and Concepts Competition.

  10. Aircraft System Design and Integration

    Directory of Open Access Journals (Sweden)

    D. P. Coldbeck

    2000-01-01

    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

  11. Aircraft systems design methodology and dispatch reliability prediction

    OpenAIRE

    Bineid, Mansour

    2005-01-01

    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 ...

  12. Improving Aircraft Design Robustness with Scenario Methods

    Directory of Open Access Journals (Sweden)

    A. Strohmayer

    2001-01-01

    Full Text Available Compared to other industries, the aerospace sector is characterized by long product cycles in a very complex environment. The aircraft manufacturer has to base his product strategy on a long-term view of risks and opportunities in the transport industry but he cannot predict the development of relevant factors in this market environment with any certainty. In this situation, scenario methods offer a pragmatic way to limit the uncertainties and to work them up methodically, in order to derive recommendations for cost-intensive strategic decisions like for example the go-ahead for a new aircraft concept. By including scenario methods in the aircraft design cycle, the ‘design robustness’ can be improved, i.e. the design is not optimised for a prognosticated operating environment, but can cope with various possible future developments. The paper will explain the three fundamental aspects in applying scenario planning to the aircraft design process: requirement definition, design evaluation and technology identification. For each aspect, methods will be shown, which connect the rather qualitative results of a scenario process with aircraft design, which typically demands a qualitative input.

  13. Design of a spanloader cargo aircraft

    Science.gov (United States)

    1989-01-01

    With a growing demand for fast international freight service, the slow-moving cargo ships currently in use will soon find a substantial portion of their clients looking elsewhere. One candidate for filling this expected gap in the freight market is a span-loading aircraft (or 'flying wing') capable of long-range operation with extremely large payloads. This report summarizes the design features of an aircraft capable of fulfilling a long-haul, high-capacity cargo mission. The spanloader seeks to gain advantage over conventional aircraft by eliminating the aircraft fuselage and thus reducing empty weight. The primary disadvantage of this configuration is that the cargo-containing wing tends to be thick, thus posing a challenge to the airfoil designer. It also suffers from stability and control problems not encountered by conventional aircraft. The result is an interesting, challenging exercise in unconventional design. The report that follows is a student written synopsis of an effort judged to be the best of eight designs developed during the year 1988-1989.

  14. Structural analysis at aircraft conceptual design stage

    Science.gov (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

  15. Aircraft System Simulation for Preliminary Design

    OpenAIRE

    Krus, Petter; Braun, Robert; Nordin, Peter; Eriksson, Björn

    2012-01-01

    Developments in computational hardware and simulation software have come to a point where it is possible to use whole mission simulation in a framework for conceptual/preliminary design. This paper is about the implementation of full system simulation software for conceptual/preliminary aircraft design. It is based on the new Hopsan NG simulation package, developed at the Linköping University. The Hopsan NG software is implemented in C++. Hopsan NG is the first simulation software that has su...

  16. Design of a control configured tanker aircraft

    Science.gov (United States)

    Walker, S. A.

    1976-01-01

    The benefits that accrue from using control configured vehicle (CCV) concepts were examined along with the techniques for applying these concepts to an advanced tanker aircraft design. Reduced static stability (RSS) and flutter mode control (FMC) were the two primary CCV concepts used in the design. The CCV tanker was designed to the same mission requirements specified for a conventional tanker design. A seven degree of freedom mathematical model of the flexible aircraft was derived and used to synthesize a lateral stability augmentation system (SAS), a longitudinal control augmentation system (CAS), and a FMC system. Fatigue life and cost analyses followed the control system synthesis, after which a comparative evaluation of the CCV and conventional tankers was made. This comparison indicated that the CCV weight and cost were lower but that, for this design iteration, the CCV fatigue life was shorter. Also, the CCV crew station acceleration was lower, but the acceleration at the boom operator station was higher relative to the corresponding conventional tanker. Comparison of the design processes used in the CCV and conventional design studies revealed that they were basically the same.

  17. Structural design for aircraft impact loading

    International Nuclear Information System (INIS)

    The distribution of military aircraft and proximity to commercial air routes requires the analysis of aircraft impact effect on nuclear power plant facilities in Europe. The 'hardened-building' approach has led to the consideration of severe shock and vibration caused by the aircraft impact and development of corresponding floor response spectra for component design. The reactor auxiliary system building allows a more defensive alternate in the form of a partially softened design. In this approach the equipment layout is arranged such that equipment performing either safety functions or having the potential for significant release of radioctivity (upon destruction) is located in the central area of the plant and is enclosed in thick concrete walls for shielding and protection purposes. The non-safety class equipment is arranged in the area peripheral to the hardened central area and enclosed in thin concrete walls. Since the kinetic energy of the impacting aircraft is absorbed by the collapsed thin walls and ceilings, the vibrational effect on the safety class equipment is drastically reduced. In order to achieve the objective of absorbing high kinetic energy and yet reduce the shock and vibration effects, the softened exterior walls require low resistance and high ductility. In order not to increase the construction cost, and yet to assure the safety of the plant, some dynamic tests of conventionally reinforced slabs have to be performed all the way to collapse. These calculations have assumptions of achieving the maximum velocity instantaneously after impact, and take into account the kinetic energy in the broken wall. Nonlinear equations of motion are also formulated and solved. The results indicate that the phantom jet would go through the first wall. The second wall would stop the jet, but would sustain some permanent deformation and damage

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

    OpenAIRE

    Clara Nieto-Wire; Kenneth Sobel

    2011-01-01

    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 ...

  19. Aircraft Conceptual Design Using Vehicle Sketch Pad

    Science.gov (United States)

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

    2010-01-01

    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.

  20. Advanced Aerostructural Optimization Techniques for Aircraft Design

    Directory of Open Access Journals (Sweden)

    Yingtao Zuo

    2015-01-01

    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.

  1. Aircraft Structural Analysis, Design Optimization, and Manufacturing Tool Integration Project

    Data.gov (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...

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

    Science.gov (United States)

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

    2014-12-01

    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.

  3. Design of heavy lift cargo aircraft

    Data.gov (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...

  4. Review of evolving trends in blended wing body aircraft design

    Science.gov (United States)

    Okonkwo, Paul; Smith, Howard

    2016-04-01

    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.

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

    OpenAIRE

    Härkegård, Ola

    2001-01-01

    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...

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

    Directory of Open Access Journals (Sweden)

    Norbert ANGI

    2015-12-01

    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.

  7. A robust optimization methodology for preliminary aircraft design

    Science.gov (United States)

    Prigent, S.; Maréchal, P.; Rondepierre, A.; Druot, T.; Belleville, M.

    2016-05-01

    This article focuses on a robust optimization of an aircraft preliminary design under operational constraints. According to engineers' know-how, the aircraft preliminary design problem can be modelled as an uncertain optimization problem whose objective (the cost or the fuel consumption) is almost affine, and whose constraints are convex. It is shown that this uncertain optimization problem can be approximated in a conservative manner by an uncertain linear optimization program, which enables the use of the techniques of robust linear programming of Ben-Tal, El Ghaoui, and Nemirovski [Robust Optimization, Princeton University Press, 2009]. This methodology is then applied to two real cases of aircraft design and numerical results are presented.

  8. Aircraft engine performance and integration in a flying wing aircraft conceptual design

    OpenAIRE

    Miao, Zhisong.

    2012-01-01

    The increasing demand of more economical and environmentally friendly aero engines leads to the proposal of a new concept – geared turbofan. In this thesis, the characteristics of this kind of engine and relevant considerations of integration on a flying wing aircraft were studied. The studies can be divided into four levels: GTF-11 engine modelling and performance simulation; aircraft performance calculation; nacelle design and aerodynamic performance evaluation; preliminar...

  9. Aircraft energy efficiency laminar flow control wing design study

    Science.gov (United States)

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

    1977-01-01

    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.

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

    CERN Document Server

    Skorupa, Andrzej

    2012-01-01

    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...

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

    Directory of Open Access Journals (Sweden)

    D. P. Coiro

    2002-01-01

    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.

  12. Needs and Challenges in Education for Aircraft Design.

    Science.gov (United States)

    Haupt, Ulrich

    A brief review of recent developments in engineering education leads to basic reflections about the importance of design education. Aircraft design is singled out as a field where demands on design are particularly high and urgent. Basic needs are determined. Additional challenges posed by engineering technology, continuing studies,…

  13. A generic tool for cost estimating in aircraft design

    NARCIS (Netherlands)

    Castagne, S.; Curran, R.; Rothwell, A.; Price, M.; Benard, E.; Raghunathan, S.

    2008-01-01

    A methodology to estimate the cost implications of design decisions by integrating cost as a design parameter at an early design stage is presented. The model is developed on a hierarchical basis, the manufacturing cost of aircraft fuselage panels being analysed in this paper. The manufacturing cost

  14. Control Design for a Generic Commercial Aircraft Engine

    Science.gov (United States)

    Csank, Jeffrey; May, Ryan D.

    2010-01-01

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

  15. The ARCTAS aircraft mission: design and execution

    Directory of Open Access Journals (Sweden)

    D. J. Jacob

    2009-08-01

    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.

  16. Eagle RTS: A design for a regional transport aircraft

    Science.gov (United States)

    Bryer, Paul; Buckles, Jon; Lemke, Paul; Peake, Kirk

    1992-01-01

    This university design project concerns the Eagle RTS (Regional Transport System), a 66 passenger, twin turboprop aircraft with a range of 836 nautical miles. It will operate with a crew of two pilots and two flight attendents. This aircraft will employ the use of aluminum alloys and composite materials to reduce the aircraft weight and increase aerodynamic efficiency. The Eagle RTS will use narrow body aerodynamics with a canard configuration to improve performance. Leading edge technology will be used in the cockpit to improve flight handling and safety. The Eagle RTS propulsion system will consist of two turboprop engines with a total thrust of approximately 6300 pounds, 3150 pounds thrust per engine, for the cruise configuration. The engines will be mounted on the aft section of the aircraft to increase passenger safety in the event of a propeller failure. Aft mounted engines will also increase the overall efficiency of the aircraft by reducing the aircraft's drag. The Eagle RTS is projected to have a takeoff distance of approximately 4700 feet and a landing distance of 6100 feet. These distances will allow the Eagle RTS to land at the relatively short runways of regional airports.

  17. The Computer Aided Aircraft-design Package (CAAP)

    Science.gov (United States)

    Yalif, Guy U.

    1994-01-01

    The preliminary design of an aircraft is a complex, labor-intensive, and creative process. Since the 1970's, many computer programs have been written to help automate preliminary airplane design. Time and resource analyses have identified, 'a substantial decrease in project duration with the introduction of an automated design capability'. Proof-of-concept studies have been completed which establish 'a foundation for a computer-based airframe design capability', Unfortunately, today's design codes exist in many different languages on many, often expensive, hardware platforms. Through the use of a module-based system architecture, the Computer aided Aircraft-design Package (CAAP) will eventually bring together many of the most useful features of existing programs. Through the use of an expert system, it will add an additional feature that could be described as indispensable to entry level engineers and students: the incorporation of 'expert' knowledge into the automated design process.

  18. A generic tool for cost estimating in aircraft design

    OpenAIRE

    Castagne, S.; Curran, R.; Rothwell, A.; Price, M.; Benard, E.; Raghunathan, S.

    2008-01-01

    A methodology to estimate the cost implications of design decisions by integrating cost as a design parameter at an early design stage is presented. The model is developed on a hierarchical basis, the manufacturing cost of aircraft fuselage panels being analysed in this paper. The manufacturing cost modelling is original and relies on a genetic-causal method where the drivers of each element of cost are identified relative to the process capability. The cost model is then extended to life cyc...

  19. On Aircraft Conceptual Design : A Framework for Knowledge Based Engineering and Design Optimization

    OpenAIRE

    Amadori, Kristian

    2008-01-01

    This thesis presents a design framework where analytical tools are linked together and operated from an efficient system level interface. The application field is aircraft conceptual design. Particular attention has been paid to CAD system integration and design optimization. Aircraft design is an inherently multidisciplinary process. The goal is to search for the design that, in the best of possible ways, fulfills the requirements. It is therefore desirable to be able to effectively investig...

  20. Probabilistic Methods for Uncertainty Propagation Applied to Aircraft Design

    Science.gov (United States)

    Green, Lawrence L.; Lin, Hong-Zong; Khalessi, Mohammad R.

    2002-01-01

    Three methods of probabilistic uncertainty propagation and quantification (the method of moments, Monte Carlo simulation, and a nongradient simulation search method) are applied to an aircraft analysis and conceptual design program to demonstrate design under uncertainty. The chosen example problems appear to have discontinuous design spaces and thus these examples pose difficulties for many popular methods of uncertainty propagation and quantification. However, specific implementation features of the first and third methods chosen for use in this study enable successful propagation of small uncertainties through the program. Input uncertainties in two configuration design variables are considered. Uncertainties in aircraft weight are computed. The effects of specifying required levels of constraint satisfaction with specified levels of input uncertainty are also demonstrated. The results show, as expected, that the designs under uncertainty are typically heavier and more conservative than those in which no input uncertainties exist.

  1. Interactive Graphics Analysis for Aircraft Design

    Science.gov (United States)

    Townsend, J. C.

    1983-01-01

    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.

  2. Engine Conceptual Design Studies for a Hybrid Wing Body Aircraft

    Science.gov (United States)

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

    2009-01-01

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

  3. 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

    2014-01-01

    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.

  4. Analysis and design technology for high-speed aircraft structures

    Science.gov (United States)

    Starnes, James H., Jr.; Camarda, Charles J.

    1992-01-01

    Recent high-speed aircraft structures research activities at NASA Langley Research Center are described. The following topics are covered: the development of analytical and numerical solutions to global and local thermal and structural problems, experimental verification of analysis methods, identification of failure mechanisms, and the incorporation of analysis methods into design and optimization strategies. The paper describes recent NASA Langley advances in analysis and design methods, structural and thermal concepts, and test methods.

  5. On how to consider climate change in aircraft design

    Directory of Open Access Journals (Sweden)

    Regina Egelhofer

    2008-04-01

    Full Text Available The increasing knowledge in atmospheric sciences and modelling has started to enable the assessment of the contribution of aviation to climate change. Aeronautical engineering therefore has to consider explicitly Earth's atmosphere in future aircraft design. Aviation being a complex business with many different stake-holders, both configurational and operational design solutions for minimum atmospheric impact have to be evaluated for real flight operations. This paper presents a methodology providing a systemic structure for such evaluations. An exercise on two-stage operations with an existing longrange aircraft type is used to illustrate this methodology incorporating some major operational effects. Despite various limitations, the methodology highlights the fact that, in a global operational context, there remains a large gap between theoretical benefits and actual performance.

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

    Science.gov (United States)

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

    1976-01-01

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

  7. Aircraft

    Science.gov (United States)

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

    1998-01-01

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

  8. A computer-assisted process for supersonic aircraft conceptual design

    Science.gov (United States)

    Johnson, V. S.

    1985-01-01

    Design methodology was developed and existing major computer codes were selected to carry out the conceptual design of supersonic aircraft. A computer-assisted design process resulted from linking the codes together in a logical manner to implement the design methodology. The process does not perform the conceptual design of a supersonic aircraft but it does provide the designer with increased flexibility, especially in geometry generation and manipulation. Use of the computer-assisted process for the conceptual design of an advanced technology Mach 3.5 interceptor showed the principal benefit of the process to be the ability to use a computerized geometry generator and then directly convert the geometry between formats used in the geometry code and the aerodynamics codes. Results from the interceptor study showed that a Mach 3.5 standoff interceptor with a 1000 nautical-mile mission radius and a payload of eight Phoenix missiles appears to be feasible with the advanced technologies considered. A sensitivity study showed that technologies affecting the empty weight and propulsion system would be critical in the final configuration characteristics with aerodynamics having a lesser effect for small perturbations around the baseline.

  9. Optimized Reconfigurable Control Design for Aircraft using Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Arsalan H. Khan

    2013-12-01

    Full Text Available In this study, we propose a Genetic Algorithm (GA based modular reconfigurable control scheme for an over-actuated non-linear aircraft model. The reconfiguration of the flight controller is achieved for the case of control surface faults/failures using a separate control distribution algorithm without modifying the base-line control law. The baseline Multi-Input Multi-Output (MIMO Linear Quadratic Regulator (LQR is optimized using GA to produce desired moment commands. Then, a GA based weighted pseudo-inverse method is used for effective distribution of commands between redundant control surfaces. Control surface effectiveness levels are used to redistribute the control commands to healthy actuators when a fault or failure occurs. Simulation results using ADMIRE aircraft model show the satisfactory performance in accommodating different faults, which confirm the efficiency of optimized reconfigurable design strategy.

  10. Data on the Design of Plywood for Aircraft

    Science.gov (United States)

    Elmendorf, Armin

    1921-01-01

    This report makes available data which will aid the designer in determining the plywood that is best adapted to various aircraft parts. It gives the results of investigations made by the Forest Products Laboratory of the United States Forest Service at Madison, Wisconsin, for the Army and Navy Departments, and is one of a series of reports on the use of wood in aircraft prepared by the Forest Products Laboratory for publication by the National Advisory Committee for Aeronautics. The object of the study was to determine, through comprehensive tests, the mechanical and physical properties of plywood and how these properties vary with density, number, thickness, arrangement of the plies and direction of grain of the plies.

  11. Conceptual design of hybrid-electric transport aircraft

    Science.gov (United States)

    Pornet, C.; Isikveren, A. T.

    2015-11-01

    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

  12. Landing Gear Integration in Aircraft Conceptual Design. Revision

    Science.gov (United States)

    Chai, Sonny T.; Mason, William H.

    1997-01-01

    The design of the landing gear is one of the more fundamental aspects of aircraft design. The design and integration process encompasses numerous engineering disciplines, e.g., structure, weights, runway design, and economics, and has become extremely sophisticated in the last few decades. Although the design process is well-documented, no attempt has been made until now in the development of a design methodology that can be used within an automated environment. As a result, the process remains to be a key responsibility for the configuration designer and is largely experience-based and graphically-oriented. However, as industry and government try to incorporate multidisciplinary design optimization (MDO) methods in the conceptual design phase, the need for a more systematic procedure has become apparent. The development of an MDO-capable design methodology as described in this work is focused on providing the conceptual designer with tools to help automate the disciplinary analyses, i.e., geometry, kinematics, flotation, and weight. Documented design procedures and analyses were examined to determine their applicability, and to ensure compliance with current practices and regulations. Using the latest information as obtained from industry during initial industry survey, the analyses were in terms modified and expanded to accommodate the design criteria associated with the advanced large subsonic transports. Algorithms were then developed based on the updated analysis procedures to be incorporated into existing MDO codes.

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

    Directory of Open Access Journals (Sweden)

    V.B. Goley

    2006-01-01

    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.

  14. Aircraft-Fuel-Tank Design for Liquid Hydrogen

    Science.gov (United States)

    Reynolds, T W

    1955-01-01

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

  15. An Advanced Open-Source Aircraft Design Platform for Personal Air Vehicle Geometry, Aerodynamics, and Structures Project

    Data.gov (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...

  16. An integrated systems engineering approach to aircraft design

    Science.gov (United States)

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

    2006-06-01

    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

  17. Design and Testing of a Flight Control System for Unstable Subscale Aircraft

    OpenAIRE

    Sobron, Alejandro

    2015-01-01

    The primary objective of this thesis was to study, implement, and test low-cost electronic flight control systems (FCS) in remotely piloted subscale research aircraft with relaxed static longitudinal stability. Even though this implementation was carried out in small, simplified test-bed aircraft, it was designed with the aim of being installed later in more complex demonstrator aircraft such as the Generic Future Fighter concept demonstrator project. The recent boom of the unmanned aircraft ...

  18. Damage tolerant wing-fuselage integration structural design applicable to future BWB transport aircraft

    OpenAIRE

    Sodzi, P.

    2009-01-01

    Wing joint design is one of the most critical areas in aircraft structures. Efficient and damage tolerant wing-fuselage integration structure, applicable to the next generation of transport aircraft, will facilitate the realisation of the benefits offered by new aircraft concepts. The Blended Wing Body (BWB) aircraft concept represents a potential revolution in subsonic transport efficiency for large airplanes. Studies have shown the BWB to be superior to conventional airframes...

  19. Equivalent plate modeling for conceptual design of aircraft wing structures

    Science.gov (United States)

    Giles, Gary L.

    1995-01-01

    This paper describes an analysis method that generates conceptual-level design data for aircraft wing structures. A key requirement is that this data must be produced in a timely manner so that is can be used effectively by multidisciplinary synthesis codes for performing systems studies. Such a capability is being developed by enhancing an equivalent plate structural analysis computer code to provide a more comprehensive, robust and user-friendly analysis tool. The paper focuses on recent enhancements to the Equivalent Laminated Plate Solution (ELAPS) analysis code that significantly expands the modeling capability and improves the accuracy of results. Modeling additions include use of out-of-plane plate segments for representing winglets and advanced wing concepts such as C-wings along with a new capability for modeling the internal rib and spar structure. The accuracy of calculated results is improved by including transverse shear effects in the formulation and by using multiple sets of assumed displacement functions in the analysis. Typical results are presented to demonstrate these new features. Example configurations include a C-wing transport aircraft, a representative fighter wing and a blended-wing-body transport. These applications are intended to demonstrate and quantify the benefits of using equivalent plate modeling of wing structures during conceptual design.

  20. Overall design of imaging spectrometer on-board light aircraft

    Energy Technology Data Exchange (ETDEWEB)

    Zhongqi, H.; Zhengkui, C.; Changhua, C.

    1996-11-01

    Aerial remote sensing is the earliest remote sensing technical system and has gotten rapid development in recent years. The development of aerial remote sensing was dominated by high to medium altitude platform in the past, and now it is characterized by the diversity platform including planes of high-medium-low flying altitude, helicopter, airship, remotely controlled airplane, glider, and balloon. The widely used and rapidly developed platform recently is light aircraft. Early in the close of 1970s, Beijing Research Institute of Uranium Geology began aerial photography and geophysical survey using light aircraft, and put forward the overall design scheme of light aircraft imaging spectral application system (LAISAS) in 19905. LAISAS is comprised of four subsystem. They are called measuring platform, data acquiring subsystem, ground testing and data processing subsystem respectively. The principal instruments of LAISAS include measuring platform controlled by inertia gyroscope, aerial spectrometer with high spectral resolution, imaging spectrometer, 3-channel scanner, 128-channel imaging spectrometer, GPS, illuminance-meter, and devices for atmospheric parameters measuring, ground testing, data correction and processing. LAISAS has the features of integrity from data acquisition to data processing and to application; of stability which guarantees the image quality and is comprised of measuring, ground testing device, and in-door data correction system; of exemplariness of integrated the technology of GIS, GPS, and Image Processing System; of practicality which embodied LAISAS with flexibility and high ratio of performance to cost. So, it can be used in the fields of fundamental research of Remote Sensing and large-scale mapping for resource exploration, environmental monitoring, calamity prediction, and military purpose.

  1. Development of a combat aircraft operational and cost-effectiveness design methodology

    OpenAIRE

    Nilubol, Otsin

    2005-01-01

    This study set out to develop an aircraft design methodology, which gives com- bat aircraft more operational and cost-effectiveness by considering these factors early in the design process. In this methodology, an aircraft will be considered as a sub-system of an overall system, representing an entire operation scenario. Measures of operational and operational cost-effectiveness indicate the quality of, and relationships between, the major design aspects; i. e. susceptibility, ...

  2. Next Generation Civil Transport Aircraft Design Considerations for Improving Vehicle and System-Level Efficiency

    Science.gov (United States)

    Acosta, Diana M.; Guynn, Mark D.; Wahls, Richard A.; DelRosario, Ruben,

    2013-01-01

    The future of aviation will benefit from research in aircraft design and air transportation management aimed at improving efficiency and reducing environmental impacts. This paper presents civil transport aircraft design trends and opportunities for improving vehicle and system-level efficiency. Aircraft design concepts and the emerging technologies critical to reducing thrust specific fuel consumption, reducing weight, and increasing lift to drag ratio currently being developed by NASA are discussed. Advancements in the air transportation system aimed towards system-level efficiency are discussed as well. Finally, the paper describes the relationship between the air transportation system, aircraft, and efficiency. This relationship is characterized by operational constraints imposed by the air transportation system that influence aircraft design, and operational capabilities inherent to an aircraft design that impact the air transportation system.

  3. Aircraft conceptual design - an adaptable parametric sizing methodology

    Science.gov (United States)

    Coleman, Gary John, Jr.

    Aerospace is a maturing industry with successful and refined baselines which work well for traditional baseline missions, markets and technologies. However, when new markets (space tourism) or new constrains (environmental) or new technologies (composite, natural laminar flow) emerge, the conventional solution is not necessarily best for the new situation. Which begs the question "how does a design team quickly screen and compare novel solutions to conventional solutions for new aerospace challenges?" The answer is rapid and flexible conceptual design Parametric Sizing. In the product design life-cycle, parametric sizing is the first step in screening the total vehicle in terms of mission, configuration and technology to quickly assess first order design and mission sensitivities. During this phase, various missions and technologies are assessed. During this phase, the designer is identifying design solutions of concepts and configurations to meet combinations of mission and technology. This research undertaking contributes the state-of-the-art in aircraft parametric sizing through (1) development of a dedicated conceptual design process and disciplinary methods library, (2) development of a novel and robust parametric sizing process based on 'best-practice' approaches found in the process and disciplinary methods library, and (3) application of the parametric sizing process to a variety of design missions (transonic, supersonic and hypersonic transports), different configurations (tail-aft, blended wing body, strut-braced wing, hypersonic blended bodies, etc.), and different technologies (composite, natural laminar flow, thrust vectored control, etc.), in order to demonstrate the robustness of the methodology and unearth first-order design sensitivities to current and future aerospace design problems. This research undertaking demonstrates the importance of this early design step in selecting the correct combination of mission, technologies and configuration to

  4. Conceptual design for a laminar-flying-wing aircraft

    Science.gov (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

  5. 76 FR 3540 - U.S. Advanced Boiling Water Reactor Aircraft Impact Design Certification Amendment

    Science.gov (United States)

    2011-01-20

    ... COMMISSION 10 CFR Part 52 RIN 3150-AI84 U.S. Advanced Boiling Water Reactor Aircraft Impact Design... the U.S. Advanced Boiling Water Reactor (ABWR) standard plant design to comply with the NRC's aircraft...--Design Certification Rule for the U.S. Advanced Boiling Water Reactor IV. Section-by-Section Analysis...

  6. A Novel Design of Aircraft Fuel Tank Inspection Robot

    Directory of Open Access Journals (Sweden)

    Guochen Niu

    2013-07-01

    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.  

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

    OpenAIRE

    Wang Yu; Yin Hailian; Zhang Shuai; Yu Xiongqing

    2014-01-01

    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 emissio...

  8. Reaction-time relationship and structural design of reinforced concrete slabs and shells for aircraft impact

    International Nuclear Information System (INIS)

    This paper outlines a rational procedure by which reinforced concrete structures such as slabs and shells may be designed to retain the required structural integrity after an aircraft impact. The paper presents a new estimate of the reaction-time relationship for impacting aircraft. A new estimate of the punching shear capacity is proposed. In addition, a simple, rotational design procedure is presented. (Auth.)

  9. The vehicle design evaluation program - A computer-aided design procedure for transport aircraft

    Science.gov (United States)

    Oman, B. H.; Kruse, G. S.; Schrader, O. E.

    1977-01-01

    The vehicle design evaluation program is described. This program is a computer-aided design procedure that provides a vehicle synthesis capability for vehicle sizing, external load analysis, structural analysis, and cost evaluation. The vehicle sizing subprogram provides geometry, weight, and balance data for aircraft using JP, hydrogen, or methane fuels. The structural synthesis subprogram uses a multistation analysis for aerodynamic surfaces and fuselages to develop theoretical weights and geometric dimensions. The parts definition subprogram uses the geometric data from the structural analysis and develops the predicted fabrication dimensions, parts material raw stock buy requirements, and predicted actual weights. The cost analysis subprogram uses detail part data in conjunction with standard hours, realization factors, labor rates, and material data to develop the manufacturing costs. The program is used to evaluate overall design effects on subsonic commercial type aircraft due to parameter variations.

  10. Flying Qualities Metrics and Design Guidelines for Modern Transport Aircraft Project

    Data.gov (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...

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

    Science.gov (United States)

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

    2000-01-01

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

  12. Conceptual Design of New Low-Noise Aircraft

    OpenAIRE

    Bertsch, Lothar

    2015-01-01

    Noise levels generated by aircraft (and rotorcraft) can be assigned to the loudest noise sources of our times. Sound pressure levels close to a jet aircraft engine under take‐off conditions can reach the human threshold of pain with respect to noise. Aircraft ground noise levels comparable to a heavy truck passing by, i.e. maximum levels in the order of 70 to 80 dBA, can still be measured at large distances up to 20 kilometers away from the actual airport premises (FUSSNOTE: website http:/...

  13. Automated Tetrahedral Mesh Generation for CFD Analysis of Aircraft in Conceptual Design

    Science.gov (United States)

    Ordaz, Irian; Li, Wu; Campbell, Richard L.

    2014-01-01

    The paper introduces an automation process of generating a tetrahedral mesh for computational fluid dynamics (CFD) analysis of aircraft configurations in early conceptual design. The method was developed for CFD-based sonic boom analysis of supersonic configurations, but can be applied to aerodynamic analysis of aircraft configurations in any flight regime.

  14. Mathematical Models for Aircraft Trajectory Design : A Survey

    OpenAIRE

    Delahaye, Daniel; Puechmorel, Stéphane; Tsiotras, Panagiotis; Féron, Éric

    2014-01-01

    Air traffic management ensures the safety of flight by optimizing flows and maintaining separation between aircraft. After giving some definitions, some typical feature of aircraft trajectories are presented. Trajectories are objects belonging to spaces with infinite dimensions. The naive way to address such problem is to sample trajectories at some regular points and to create a big vector of positions (and or speeds). In order to manipulate such objects with algorithms, one must reduce the ...

  15. A light lithium niobate transducer design and ultrasonic de-icing research for aircraft wing

    International Nuclear Information System (INIS)

    Due to the strong piezoelectric effect possessed by lithium niobate and the fact that the adhesive bond of ice–substrate interface is relatively weak in shear, an ultrasonic de-icing technique that uses lithium niobate to design a light transducer for aircraft wing de-icing is proposed in this paper. The main contents of this paper are as follows: Firstly, a light de-icing lithium niobate transducer is designed to affix on the inner surface of the leading edge at the locations, where highest amount of ice accretion on the outer surface occurs. Secondly, the outdoor wing de-icing experiments are conducted to determine the optimal ultrasonic de-icing frequency. Finally, the design scheme of light-weight supersonic generator installed in the aircraft is presented. Research results show that this de-icing technique for aircraft wing de-icing is feasible, promising for further investigation. - Highlights: • A light lithium niobate transducer for aircraft wing de-icing is designed. • Theory and experiment show that ulreasonic de-icing for aircraft wing is feasible. • The optimum frequency of aircraft wing ultrasonic de-icing is given. • Lightweight design scheme of supersonic generator installed in aircraft is given

  16. Seat Capacity Selection for an Advanced Short-Haul Aircraft Design

    Science.gov (United States)

    Marien, Ty V.

    2016-01-01

    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.

  17. 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)

    2007-07-01

    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.

  18. Safety design of nuclear power plants against aircraft impacts

    International Nuclear Information System (INIS)

    This paper presents a number of techniques which may be utilized to accomplish the above objectives. Firstly, a re-evaluation is made of aircraft crash probabilities. Secondly, methods are described for calculating aircraft impact forcing functions, for obtaining probability distributions for the impact parameters. Thirdly, evaluations are made for assessing the probability that an impact on a given structure will result in consequences exceeding those listed in 10 CFR 100 and recommendations are made for treating lower consequence events. Finally, other effects such as fires, explosions and secondary missiles are examined briefly

  19. Multilevel optimization problem setting for the design of electric aircraft networks

    OpenAIRE

    Hadbi, Djamel

    2015-01-01

    Within more electric aircraft context, electric systems and networks have to evolve. High energy density integration pushes designers to reconsider their systems, architectures and tools.An aircraft network contains a large number of multidisciplinary systems which come from different manufacturers. Each manufacturer designs its system separately following quality standards specified by the aggregator. The goal of this thesis is to provide system approaches which could deal with the high-leve...

  20. Optimal design of a flying-wing aircraft inner wing structure configuration

    OpenAIRE

    HUANG, HAIDONG

    2012-01-01

    Flying-wing aircraft are considered to have great advantages and potentials in aerodynamic performance and weight saving. However, they also have many challenges in design. One of the biggest challenges is the structural design of the inner wing (fuselage). Unlike the conventional fuselage of a tube configuration, the flying-wing aircraft inner wing cross section is limited to a noncircular shape, which is not structurally efficient to resist the internal pressure load. In o...

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

    Science.gov (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.

  2. Aeroelastic Loads Modeling for Composite Aircraft Design Support

    NARCIS (Netherlands)

    Baluch, H.A.

    2009-01-01

    With regard to the simulation of structural vibrations and consequent aeroelastic loads in aircraft components, the use of elastic axis e.a as reference of vibrations is quite common. The e.a decouples the bending and torsion degrees of freedom (D.o.F) during the dynamic analysis. The use of the e.a

  3. The design and testing of subscale smart aircraft wing bolts

    International Nuclear Information System (INIS)

    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. (paper)

  4. The design and testing of subscale smart aircraft wing bolts

    Science.gov (United States)

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

    2012-07-01

    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.

  5. 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

    2015-02-01

    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.

  6. Application of powered lift and mechanical flap concepts for civil short-haul transport aircraft design

    Science.gov (United States)

    Conlon, J. A.; Bowles, J. V.

    1977-01-01

    The objective of this paper is to determine various design and performance parameters, including wing loading and thrust loading requirements, for powered-lift and mechanical flap conceptual aircraft constrained by field length and community noise impact. Mission block fuel and direct operating costs (DOC) were found for optimum designs. As a baseline, the design and performance parameters were determined for the aircraft using engines without noise suppression. The constraint of the 90 EPNL noise contour being less than 2.6 sq km (1.0 sq mi) in area was then imposed. The results indicate that for both aircraft concepts the design gross weight, DOC, and required mission block fuel decreased with field length. At field lengths less than 1100 m (3600 ft) the powered lift aircraft had lower DOC and block fuel than the mechanical flap aircraft but produced higher unsuppressed noise levels. The noise goal could easily be achieved with nacelle wall treatment only and thus resulted in little or no performance or weight penalty for all studied aircraft.

  7. Longitudinal control laws design for a flying wing aircraft

    OpenAIRE

    Zhu, Yan

    2012-01-01

    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...

  8. Simple hybrid propulsion model for hybrid aircraft design space exploration

    OpenAIRE

    Belleville, Mathieu

    2015-01-01

    International audience This article introduces a semi-empirical model for an electric fan and a minimalistic model for a turbofan. The electric fan model provides an easy selection of optimal characteristics based on power loading. The turbofan model has provision for power extraction, and exhibit a physical behaviour. These two models allowed exploring the performance of a hybrid-electric aircraft featuring two turbofans under the wing and one electric fan at the rear of the fuselage. Ass...

  9. Optimal Input Design for Aircraft Parameter Estimation using Dynamic Programming Principles

    Science.gov (United States)

    Morelli, Eugene A.; Klein, Vladislav

    1990-01-01

    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.

  10. Design of a digital ride quality augmentation system for a commuter aircraft

    Science.gov (United States)

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

    1984-01-01

    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.

  11. Design of a Total Pressure Distortion Generator for Aircraft Engine Testing

    OpenAIRE

    Cramer, Kevin Brendan

    2002-01-01

    Design of Total Pressure Distortion Generator for Aircraft Engine Testing by Kevin B. Cramer Committee Co-Chair: W.F. Oâ Brien Committee Co-Chair: P.S. King Mechanical Engineering (ABSTRACT) A new method and mechanism for generating non-uniform, or distorted, aircraft engine inlet flow is being developed in order to account for dynamic changes during the creation and propagation of the distortion. Total pressure distortions occur in gas turbine engines when the i...

  12. Multi-disciplinary, community-oriented design of low-noise aircraft: the COSMA project

    OpenAIRE

    Iemma Umberto

    2016-01-01

    The EC-funded project COSMA (Community Oriented Solutions to Minimize aircraft noise Annoyance, 7th Framework Programme) started in June 2009 with an ambitious, twofold goal: improve the understanding of the annoyance induced by aircraft noise on the population and identify the engineering guidelines to establish appropriate design strategies and operational procedure to reduce these effects. The project was conceived within the context of the X-Noise Collaborative Net...

  13. Comparison between system design optimization strategies for more electric aircraft networks

    OpenAIRE

    Hadbi, Djamel; Retière, Nicolas; Wurtz, Frédéric; Roboam, Xavier; Sareni, Bruno

    2014-01-01

    Nowadays, embedded aircraft system contains electrical devices which must cooperate in safe and light weight network. For designing such systems, different local strategies have been developed but no global optimization has been performed so far. In this paper, we present and compare three strategies applied to the sizing of a whole network of more electric aircraft: a simplified case study with only two components is considered to illustrate methodological issues. The quality of the solution...

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

    OpenAIRE

    Dorbath, Felix; Nagel, Björn; Gollnick, Volker

    2011-01-01

    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...

  15. Cargo Aircraft Conceptual Design Optimisation Using a Flexible Computer-Based Scaling Approach

    Directory of Open Access Journals (Sweden)

    F. Schieck

    2001-01-01

    Full Text Available In the early design stages of a new aircraft, there is a strong need to broaden the knowledge base of the evolving aircraft project, allowing a profound analysis of the solution concepts and of the design driving requirements. The methodology presented in this paper provides a tool for increasing and improving in an exemplary manner the necessary information on cargo aircraft. By exchanging or adapting a few particular modules of the entire program system, the tool is applicable to a range scale of different aircraft types. In an extended requirement model, performance requirements are represented along with other operational requirements. An aircraft model is introduced in sufficient detail for conceptual design considerations. The computer-aided scaling methodology is explained, which, controlled by an optimisation module, automatically resizes the aircraft model until it optimally satisfies the requirements in terms of a selectable figure of merit. Typical results obtained at the end of the scaling are discussed together with knowledge gained during the process, and an example is given.

  16. Toward Reduced Aircraft Community Noise Impact Via a Perception-Influenced Design Approach

    Science.gov (United States)

    Rizzi, Stephen A.

    2016-01-01

    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.

  17. Conceptual design of a flying boom for air-to-air refueling of passenger aircraft

    Science.gov (United States)

    Timmermans, Ir. H. S.; La Rocca, ir. G., Dr.

    2014-10-01

    This paper describes the conceptual development of a flying boom for air-to-air refuelingof passenger aircraft. This operational concept is currently evaluated within the EC project RECREATE as a possible means to achieve significant increase in overall fuel efficiency. While in military aviation aerial refueling is performed with the tankerflyingahead and above the receiver aircraft, in case of passenger aircraft, safety, cost and comfort criteria suggest to invert the set up. This unconventional configuration would require a different refueling boom, able to extend from the tanker towards the cruiser, against wind and gravity. Amultidisciplinary design optimization framework was set up to size and compare various boom design solutions free of structural divergence and sufficientlycontrollable and with minimum values of weight and drag. Oneconcept, based on an innovative kinematic mechanism, was selected for its ability to meet all design constraints, with weight and drag values comparable to conventional boom designs.

  18. Aircraft Design Automation and Subscale Testing : With Special Reference to Micro Air Vehicles

    OpenAIRE

    Lundström, David

    2012-01-01

    This dissertation concerns how design automation as well as rapid prototyping and testing of subscale prototypes can support aircraft design. A framework for design automation has been developed and is applied specifically to Micro Air Vehicles (MAV). MAVs are an interesting area for design automation as they are an application where the entire design, from requirements to manufacturing, can indeed be automated. From a complexity point of view it can be considered to be similar to conceptual ...

  19. Analytical Design Package (ADP2): A computer aided engineering tool for aircraft transparency design

    Science.gov (United States)

    Wuerer, J. E.; Gran, M.; Held, T. W.

    1994-01-01

    The Analytical Design Package (ADP2) is being developed as a part of the Air Force Frameless Transparency Program (FTP). ADP2 is an integrated design tool consisting of existing analysis codes and Computer Aided Engineering (CAE) software. The objective of the ADP2 is to develop and confirm an integrated design methodology for frameless transparencies, related aircraft interfaces, and their corresponding tooling. The application of this methodology will generate high confidence for achieving a qualified part prior to mold fabrication. ADP2 is a customized integration of analysis codes, CAE software, and material databases. The primary CAE integration tool for the ADP2 is P3/PATRAN, a commercial-off-the-shelf (COTS) software tool. The open architecture of P3/PATRAN allows customized installations with different applications modules for specific site requirements. Integration of material databases allows the engineer to select a material, and those material properties are automatically called into the relevant analysis code. The ADP2 materials database will be composed of four independent schemas: CAE Design, Processing, Testing, and Logistics Support. The design of ADP2 places major emphasis on the seamless integration of CAE and analysis modules with a single intuitive graphical interface. This tool is being designed to serve and be used by an entire project team, i.e., analysts, designers, materials experts, and managers. The final version of the software will be delivered to the Air Force in Jan. 1994. The Analytical Design Package (ADP2) will then be ready for transfer to industry. The package will be capable of a wide range of design and manufacturing applications.

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

    OpenAIRE

    De Toro Diaz, Aleix

    2015-01-01

    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...

  1. Data management in an object-oriented distributed aircraft conceptual design environment

    Science.gov (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

  2. Assessment of aircraft impact loads on the design of ITER buildings

    International Nuclear Information System (INIS)

    The design of ITER buildings and main mechanical components must consider the effect of a variety of external hazards, being aircraft impact among them. Therefore, it is the objective of the work presented in this paper to perform a first assessment on the subject. The methodology proposed by ITER to assess the effect of aircraft impact on the design of the Tokamak Complex is inspired by ETCC, which was developed for the European Pressurized Reactor. Thus, its applicability to ITER experimental nuclear facilities may raise some specific problems, since the consequences of the methodology and model proposed for aircraft impacts are not very well known. The work presented in this paper aims to assess the applicability of the dynamic simplified model proposed by ITER and perform a first check of the basic design of the aircraft crash protection concrete structure of the Tokamak Complex. The analysis is based on the simplified methodology, and is limited to a limited number of configurations. Moreover, in order to provide a guide for definition of the final geometry, the material choices of concrete structures, and the steel reinforcement ratios of the aircraft crash protection structures, an optimization analyses has been performed. It is important to note that, since the Tokamak Complex is seismically isolated in the horizontal plane, the floor response spectra (FRS) caused by an aircraft impact could be more important than those induced by seismic action. Therefore, in order to make a preliminary assessment on this issue, the FRS caused by an aircraft impact in some representative scenarios has been generated.

  3. Design of the Next Generation Aircraft Noise Prediction Program: ANOPP2

    Science.gov (United States)

    Lopes, Leonard V., Dr.; Burley, Casey L.

    2011-01-01

    The requirements, constraints, and design of NASA's next generation Aircraft NOise Prediction Program (ANOPP2) are introduced. Similar to its predecessor (ANOPP), ANOPP2 provides the U.S. Government with an independent aircraft system noise prediction capability that can be used as a stand-alone program or within larger trade studies that include performance, emissions, and fuel burn. The ANOPP2 framework is designed to facilitate the combination of acoustic approaches of varying fidelity for the analysis of noise from conventional and unconventional aircraft. ANOPP2 integrates noise prediction and propagation methods, including those found in ANOPP, into a unified system that is compatible for use within general aircraft analysis software. The design of the system is described in terms of its functionality and capability to perform predictions accounting for distributed sources, installation effects, and propagation through a non-uniform atmosphere including refraction and the influence of terrain. The philosophy of mixed fidelity noise prediction through the use of nested Ffowcs Williams and Hawkings surfaces is presented and specific issues associated with its implementation are identified. Demonstrations for a conventional twin-aisle and an unconventional hybrid wing body aircraft configuration are presented to show the feasibility and capabilities of the system. Isolated model-scale jet noise predictions are also presented using high-fidelity and reduced order models, further demonstrating ANOPP2's ability to provide predictions for model-scale test configurations.

  4. Study of Aerodynamic Design Procedure of a Large-Scale Aircraft Noise Suppression Facility

    Science.gov (United States)

    Kawai, Masafumi; Nagai, Kiyoyuki; Aso, Shigeru

    The aerodynamic design procedure of a large-scale aircraft noise suppression facility has been developed. Flow quality required for the engine inlet flow has been determined through basic experiment. Aerodynamic design of the facility has been performed by using wind tunnel experiment and CFD. Important relationship between the length of the facility and the inlet flow quality has been found. The operational envelope of the designed facility has been estimated. Then, the aerodynamic characteristics of an actual large-scale aircraft noise suppression facility, constructed based on the new design procedure, have been measured. Obtained flow field showed good agreement with CFD results, and the effectiveness of the design procedure based on CFD and wind tunnel experiment has been confirmed. The engine operations were satisfactory under various wind conditions. Furthermore, the data under commercial operations thereafter have been collected and analyzed. As the result, the aerodynamic design procedure has been validated.

  5. ENFICA-FC: Design of transport aircraft powered by fuel cell & flight test of zero emission 2-seater aircraft powered by fuel cells fueled by hydrogen

    OpenAIRE

    Cestino, Enrico; Borello, Fabio; Romeo, Giulio

    2013-01-01

    Fuel cells could become the main power source for small general aviation aircraft or could replace APU and internal sub-systems on larger aircraft, to obtain all-electric or more-electric air vehicles. There are several potential advantages of using such a power source, that range from environmental and economic issues to performance and operability aspects. A preliminary design is reported. Also, the paper contains a description of testing activities related to experimental flights of an all...

  6. Improving aircraft conceptual design - A PHIGS interactive graphics interface for ACSYNT

    Science.gov (United States)

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

    1988-01-01

    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.

  7. Design and Analysis of Composite Propeller Blade for Aircraft

    OpenAIRE

    Madhusudhan BM; Dr P.V Srihari

    2014-01-01

    Fiber reinforced composites is used for twin blade propeller because of its high strength, low temperature applications. Fiber has to be oriented in the loading direction while designing the composite propeller blade. The blade geometry and design are more complex involving many controlling parameters. In the present work a methodology to design a composite propeller to analyze its strength and deformation using ANSYS software. The weight of the composite blade is reduced comp...

  8. Evaluation of structural design concepts for an arrow-wing supersonic cruise aircraft

    Science.gov (United States)

    Sakata, I. F.; Davis, G. W.

    1977-01-01

    An analytical study was performed to determine the best structural approach for design of primary wing and fuselage structure of a Mach 2.7 arrow wing supersonic cruise aircraft. Concepts were evaluated considering near term start of design. Emphasis was placed on the complex interactions between thermal stress, static aeroelasticity, flutter, fatigue and fail safe design, static and dynamic loads, and the effects of variations in structural arrangements, concepts and materials on these interactions. Results indicate that a hybrid wing structure incorporating low profile convex beaded and honeycomb sandwich surface panels of titanium alloy 6Al-4V were the most efficient. The substructure includes titanium alloy spar caps reinforced with boron polyimide composites. The fuselage shell consists of hat stiffened skin and frame construction of titanium alloy 6Al-4V. A summary of the study effort is presented, and a discussion of the overall logic, design philosophy and interaction between the analytical methods for supersonic cruise aircraft design are included.

  9. Aerodynamic design and analysis system for supersonic aircraft. Part 3: Computer program description

    Science.gov (United States)

    Middleton, W. D.; Lundry, J. L.; Coleman, R. G.

    1975-01-01

    The computer program for the design and analysis of supersonic aircraft configurations is presented. The schematics of the program structure are provided. The individual overlays and subroutines are described. The system is useful in determining surface pressures and supersonic area rule concepts.

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

    NARCIS (Netherlands)

    Vos, R.; Van Dommelen, J.

    2012-01-01

    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

  11. Design study of a French nuclear plant under aircraft impact according to German guidelines

    International Nuclear Information System (INIS)

    Subject of the paper is the presentation of an aircraft protection for the reactor building and the electrical building of the French nuclear plant P'4 or N4 against the aircraft impact load conditions according to German guidelines. Furthermore, floor response spectra in the interior of the two buildings are evaluated for the induced vibrations resistant design of components. The presented solution leads to acceptable values of either necessary bending and stirrup reinforcements and of the level of equipment accelerations for the reactor building as well as for the electrical building. (author)

  12. Design of Carbon Composite Driveshaft for Ultralight Aircraft Propulsion System

    Directory of Open Access Journals (Sweden)

    R. Poul

    2006-01-01

    Full Text Available This paper deals with the design of the carbon fibre composite driveshaft. This driveshaft will be used for connection between piston engine and propulsor of the type of axial-flow fan. Three different versions of driveshaft were designed and produced. Version 1 if completely made of Al alloy. Version 2 is of hybrid design where the central part is made of high strength carbon composite and flanges are made of Al alloy. Adhesive bond is used for connection between flanges and the central CFRP tube. Version 3 differs from the version 2 by aplication of ultrahigh-strength carbon fibre on the central part. Dimensions and design conditions are equal for all three versions to obtain simply comparable results. Calculations of driveshafts are described in the paper. 

  13. 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

    2014-01-01

    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.

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

    Directory of Open Access Journals (Sweden)

    Wang Yu

    2014-02-01

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

  15. ACSYNT - A standards-based system for parametric, computer aided conceptual design of aircraft

    Science.gov (United States)

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

    1992-01-01

    A group of eight US aerospace companies together with several NASA and NAVY centers, led by NASA Ames Systems Analysis Branch, and Virginia Tech's CAD Laboratory agreed, through the assistance of Americal Technology Initiative, in 1990 to form the ACSYNT (Aircraft Synthesis) Institute. The Institute is supported by a Joint Sponsored Research Agreement to continue the research and development in computer aided conceptual design of aircraft initiated by NASA Ames Research Center and Virginia Tech's CAD Laboratory. The result of this collaboration, a feature-based, parametric computer aided aircraft conceptual design code called ACSYNT, is described. The code is based on analysis routines begun at NASA Ames in the early 1970's. ACSYNT's CAD system is based entirely on the ISO standard Programmer's Hierarchical Interactive Graphics System and is graphics-device independent. The code includes a highly interactive graphical user interface, automatically generated Hermite and B-Spline surface models, and shaded image displays. Numerous features to enhance aircraft conceptual design are described.

  16. Robust Flight Control Design to Minimize Aircraft Loss-of-Control Incidents

    OpenAIRE

    Hess, Ronald

    2013-01-01

    A pseudo-sliding mode control synthesis procedure discussed previously in the literature is applied to the design of a control system for a nonlinear model of the NASA Langley Generic Transport Model. The complete vehicle model is included as an appendix. The goal of the design effort is the synthesis of a robust control system to minimize aircraft loss-of-control by preserving fundamental pilot input—system response characteristics across the flight envelope, here including the possibility o...

  17. Structural Optimization and Design of a Strut-Braced Wing Aircraft

    OpenAIRE

    Naghshineh-Pour, Amir H.

    1998-01-01

    A significant improvement can be achieved in the performance of transonic transport aircraft using Multidisciplinary Design Optimization (MDO) by implementing truss-braced wing concepts in combination with other advanced technologies and novel design innovations. A considerable reduction in drag can be obtained by using a high aspect ratio wing with thin airfoil sections and tip-mounted engines. However, such wing structures could suffer from a significant weight penalty. Thus, the use of an ...

  18. A service life extension (SLEP) approach to operating aging aircraft beyond their original design lives

    Science.gov (United States)

    Pentz, Alan Carter

    With today's uncertain funding climate (including sequestration and continuing budget resolutions), decision makers face severe budgetary challenges to maintain dominance through all aspects of the Department of Defense (DoD). To meet war-fighting capabilities, the DoD continues to extend aircraft programs beyond their design service lives by up to ten years, and occasionally much more. The budget requires a new approach to traditional extension strategies (i.e., reuse, reset, and reclamation) for structural hardware. While extending service life without careful controls can present a safety concern, future operations planning does not consider how much risk is present when operating within sound structural principles. Traditional structural hardware extension methods drive increased costs. Decision makers often overlook the inherent damage tolerance and fatigue capability of structural components and rely on simple time- and flight-based cycle accumulation when determining aircraft retirement lives. This study demonstrates that decision makers should consider risk in addition to the current extension strategies. Through an evaluation of eight military aircraft programs and the application and simulation of F-18 turbine engine usage data, this dissertation shows that insight into actual aircraft mission data, consideration of fatigue capability, and service extension length are key factors to consider. Aircraft structural components, as well as many critical safety components and system designs, have a predefined level of conservatism and inherent damage tolerance. The methods applied in this study would apply to extensions of other critical structures such as bridges. Understanding how much damage tolerance is built into the design compared to the original design usage requirements presents the opportunity to manage systems based on risk. The study presents the sensitivity of these factors and recommends avenues for further research.

  19. Modern digital flight control system design for VTOL aircraft

    Science.gov (United States)

    Broussard, J. R.; Berry, P. W.; Stengel, R. F.

    1979-01-01

    Methods for and results from the design and evaluation of a digital flight control system (DFCS) for a CH-47B helicopter are presented. The DFCS employed proportional-integral control logic to provide rapid, precise response to automatic or manual guidance commands while following conventional or spiral-descent approach paths. It contained altitude- and velocity-command modes, and it adapted to varying flight conditions through gain scheduling. Extensive use was made of linear systems analysis techniques. The DFCS was designed, using linear-optimal estimation and control theory, and the effects of gain scheduling are assessed by examination of closed-loop eigenvalues and time responses.

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

    Directory of Open Access Journals (Sweden)

    Yang Wang

    2009-06-01

    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.

  1. Advanced stratified charge rotary aircraft engine design study

    Science.gov (United States)

    Badgley, P.; Berkowitz, M.; Jones, C.; Myers, D.; Norwood, E.; Pratt, W. B.; Ellis, D. R.; Huggins, G.; Mueller, A.; Hembrey, J. H.

    1982-01-01

    A technology base of new developments which offered potential benefits to a general aviation engine was compiled and ranked. Using design approaches selected from the ranked list, conceptual design studies were performed of an advanced and a highly advanced engine sized to provide 186/250 shaft Kw/HP under cruise conditions at 7620/25,000 m/ft altitude. These are turbocharged, direct-injected stratified charge engines intended for commercial introduction in the early 1990's. The engine descriptive data includes tables, curves, and drawings depicting configuration, performance, weights and sizes, heat rejection, ignition and fuel injection system descriptions, maintenance requirements, and scaling data for varying power. An engine-airframe integration study of the resulting engines in advanced airframes was performed on a comparative basis with current production type engines. The results show airplane performance, costs, noise & installation factors. The rotary-engined airplanes display substantial improvements over the baseline, including 30 to 35% lower fuel usage.

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

    Directory of Open Access Journals (Sweden)

    P.S. Subramanyam

    1997-07-01

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

  3. A Web-based Computer-Aided Material-Selection System for Aircraft Design

    Directory of Open Access Journals (Sweden)

    Yuanpei Lan

    2011-05-01

    Full Text Available A web-based computer-aided material-selection system for aircraft design was put forward, applying a material-selection strategy combined screening and ranking methods. This combined strategy could make good use of selection experience and material testing data, thus making the selection results more reasonable and bringing more standardization to the material selection process. The system’s Browser/ Server (B/S architecture together with its implementation details was described. The B/S system could be accessed with web browser conveniently. The system’s effectiveness was demonstrated by two aircraft-design material-selection case in actual applications. This system could help designer select suitable materials for airframe, provide knowledge for inexperienced engineer and accumulate enterprise-level material-selection expertise.

  4. Design and Analysis of Composite Propeller Blade for Aircraft

    Directory of Open Access Journals (Sweden)

    Madhusudhan BM

    2014-09-01

    Full Text Available Fiber reinforced composites is used for twin blade propeller because of its high strength, low temperature applications. Fiber has to be oriented in the loading direction while designing the composite propeller blade. The blade geometry and design are more complex involving many controlling parameters. In the present work a methodology to design a composite propeller to analyze its strength and deformation using ANSYS software. The weight of the composite blade is reduced compared to wooden blade by adopting the shell model. The present work is to carryout the static analysis of composite propeller which is a combination CFRP (Carbon Fiber Reinforced Plastics and epoxy resin materials. In order to evaluate the effectiveness of the composite blade over wooden stress analysis is performed on both the blades. To define the orientation and number of layers in the composite blade ANSYS classic software is used. From the results, the stresses of composite propeller obtained in static analysis are within the allowable stress limit. The deflection of the composite blade is less compared to the wooden blade.

  5. Modal control theory and application to aircraft lateral handling qualities design

    Science.gov (United States)

    Srinathkumar, S.

    1978-01-01

    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.

  6. Synthesis of aircraft structures using integrated design and analysis methods

    Science.gov (United States)

    Sobieszczanski-Sobieski, J.; Goetz, R. C.

    1978-01-01

    A systematic research is reported to develop and validate methods for structural sizing of an airframe designed with the use of composite materials and active controls. This research program includes procedures for computing aeroelastic loads, static and dynamic aeroelasticity, analysis and synthesis of active controls, and optimization techniques. Development of the methods is concerned with the most effective ways of integrating and sequencing the procedures in order to generate structural sizing and the associated active control system, which is optimal with respect to a given merit function constrained by strength and aeroelasticity requirements.

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

    Science.gov (United States)

    Oman, B. H.

    1977-01-01

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

  8. Study of unconventional aircraft engines designed for low energy consumption

    Science.gov (United States)

    Neitzel, R. E.; Hirschkron, R.; Johnston, R. P.

    1976-01-01

    A study of unconventional engine cycle concepts, which may offer significantly lower energy consumption than conventional subsonic transport turbofans, is described herein. A number of unconventional engine concepts were identified and parametrically studied to determine their relative fuel-saving potential. Based on results from these studies, regenerative, geared, and variable-boost turbofans, and combinations thereof, were selected along with advanced turboprop cycles for further evaluation and refinement. Preliminary aerodynamic and mechanical designs of these unconventional engine configurations were conducted and mission performance was compared to a conventional, direct-drive turofan reference engine. Consideration is given to the unconventional concepts, and their state of readiness for application. Areas of needed technology advancement are identified.

  9. Attention in aviation. [to aircraft design and pilot performance

    Science.gov (United States)

    Wickens, Christopher D.

    1987-01-01

    The relevance of four principles or mechanisms of human attention to the design of aviation systems and the performance of pilots in multitask environments, including workload prediction and measurement, control-display integration, and the use of voice and head-up displays is discussed. The principles are: the mental energy that supplies task performance (resources), the resulting cross-talk between tasks as they are made more similar (confusion), the combination of different task elements (integration), and the way in which one task is processed and another is ignored (selection or tunneling). The introduction of greater levels of complexity into the validation of attentional theories in order to approach the demands of the cockpit or ATC console is proposed.

  10. Energy supply and its effect on aircraft of the future. II - Liquid-hydrogen-fueled aircraft: Prospects and design issues.

    Science.gov (United States)

    Kirkham, F. S.; Driver, C.

    1973-01-01

    The performance of hydrogen-fueled commercial aircraft is examined in the subsonic, supersonic, and hypersonic speed regime and compared with JP-fueled systems. Hydrogen aircraft are shown to provide substantial improvements in range and payload fraction as well as to minimize or eliminate many environmental problems. The major elements of a development program required to make hydrogen-fueled aircraft a commercial reality are also outlined and the rationale for and characteristics of both a subsonic demonstrator and a high speed research airplane are described.

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

    Science.gov (United States)

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

    2012-06-01

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

  12. Weibull-Based Design Methodology for Rotating Aircraft Engine Structures

    Science.gov (United States)

    Zaretsky, Erwin; Hendricks, Robert C.; Soditus, Sherry

    2002-01-01

    The NASA Energy Efficient Engine (E(sup 3)-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 (HCF) or low-cycle fatigue (LCF). 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 Weibull slope increases, the predicted lives decrease. The predicted engine lives L(sub 5) (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 L(sub 0.1) (99.9 % probability of survival) of 9000 hr for Weibull slopes of 3, 6 and 9, are 47,391 and 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 L(sub 0.1) can vary from 9,408 to 24,911 hr.

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

    Directory of Open Access Journals (Sweden)

    Pezhman Mardanpour

    2015-01-01

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

  14. Linear matrix inequality-based proportional-integral control design with application to F-16 aircraft

    Science.gov (United States)

    Theodore, Zachary B.

    A robust proportional-integral (PI) controller was synthesized for the F-16 VISTA (Variable stability In-flight Simulator Test Aircraft) using a linear matrix inequality (LMI) approach, with the goal of eventually designing and implementing a linear parameter-varying PI controller on high performance aircraft. The combination of classical and modern control theory provides theoretically guaranteed stability and performance throughout the flight envelope and ease of implementation due to the simplicity of the PI controller structure. The controller is designed by solving a set of LMIs with pole placement constraints. This closed-loop system was simulated in MATLAB/Simulink to analyze the performance of the controller. A robust Hinfinity controller was also developed to compare performance with PI controller. The simulation results showed stability, albeit with poor performance compared to the Hinfinity controlle.

  15. Integration of Engine, Plume, and CFD Analyses in Conceptual Design of Low-Boom Supersonic Aircraft

    Science.gov (United States)

    Li, Wu; Campbell, Richard; Geiselhart, Karl; Shields, Elwood; Nayani, Sudheer; Shenoy, Rajiv

    2009-01-01

    This paper documents an integration of engine, plume, and computational fluid dynamics (CFD) analyses in the conceptual design of low-boom supersonic aircraft, using a variable fidelity approach. In particular, the Numerical Propulsion Simulation System (NPSS) is used for propulsion system cycle analysis and nacelle outer mold line definition, and a low-fidelity plume model is developed for plume shape prediction based on NPSS engine data and nacelle geometry. This model provides a capability for the conceptual design of low-boom supersonic aircraft that accounts for plume effects. Then a newly developed process for automated CFD analysis is presented for CFD-based plume and boom analyses of the conceptual geometry. Five test cases are used to demonstrate the integrated engine, plume, and CFD analysis process based on a variable fidelity approach, as well as the feasibility of the automated CFD plume and boom analysis capability.

  16. A Generic Guidance and Control Structure for Six-Degree-of-Freedom Conceptual Aircraft Design

    Science.gov (United States)

    Cotting, M. Christopher; Cox, Timothy H.

    2005-01-01

    A control system framework is presented for both real-time and batch six-degree-of-freedom simulation. This framework allows stabilization and control with multiple command options, from body rate control to waypoint guidance. Also, pilot commands can be used to operate the simulation in a pilot-in-the-loop environment. This control system framework is created by using direct vehicle state feedback with nonlinear dynamic inversion. A direct control allocation scheme is used to command aircraft effectors. Online B-matrix estimation is used in the control allocation algorithm for maximum algorithm flexibility. Primary uses for this framework include conceptual design and early preliminary design of aircraft, where vehicle models change rapidly and a knowledge of vehicle six-degree-of-freedom performance is required. A simulated airbreathing hypersonic vehicle and a simulated high performance fighter are controlled to demonstrate the flexibility and utility of the control system.

  17. Preliminary Axial Flow Turbine Design and Off-Design Performance Analysis Methods for Rotary Wing Aircraft Engines. Part 1; Validation

    Science.gov (United States)

    Chen, Shu-cheng, S.

    2009-01-01

    For the preliminary design and the off-design performance analysis of axial flow turbines, a pair of intermediate level-of-fidelity computer codes, TD2-2 (design; reference 1) and AXOD (off-design; reference 2), are being evaluated for use in turbine design and performance prediction of the modern high performance aircraft engines. TD2-2 employs a streamline curvature method for design, while AXOD approaches the flow analysis with an equal radius-height domain decomposition strategy. Both methods resolve only the flows in the annulus region while modeling the impact introduced by the blade rows. The mathematical formulations and derivations involved in both methods are documented in references 3, 4 for TD2-2) and in reference 5 (for AXOD). The focus of this paper is to discuss the fundamental issues of applicability and compatibility of the two codes as a pair of companion pieces, to perform preliminary design and off-design analysis for modern aircraft engine turbines. Two validation cases for the design and the off-design prediction using TD2-2 and AXOD conducted on two existing high efficiency turbines, developed and tested in the NASA/GE Energy Efficient Engine (GE-E3) Program, the High Pressure Turbine (HPT; two stages, air cooled) and the Low Pressure Turbine (LPT; five stages, un-cooled), are provided in support of the analysis and discussion presented in this paper.

  18. A candidate V/STOL research aircraft design concept using an S-3A aircraft and 2 Pegasus 11 engines

    Science.gov (United States)

    Lampkin, B. A.

    1980-01-01

    A candidate V/STOL research aircraft concept which uses an S-3A airframe and two Pegasus 11 engines was studied to identify a feasible V/STOL national flight facility that could be obtained at the lowest possible cost for the demonstration of V/STOL technology, inflight simulation, and flight research. The rationale for choosing the configuration, a description of the configuration, and the capability of a fully developed aircraft are discussed.

  19. A contract-based methodology for aircraft electric power system design

    OpenAIRE

    Nuzzo, P; H. Xu; Ozay, N; Finn, JB; Sangiovanni-Vincentelli, AL; Murray, RM; Donzé, A; Seshia, SA

    2014-01-01

    In an aircraft electric power system, one or more supervisory control units actuate a set of electromechanical switches to dynamically distribute power from generators to loads, while satisfying safety, reliability, and real-time performance requirements. To reduce expensive redesign steps, this control problem is generally addressed by minor incremental changes on top of consolidated solutions. A more systematic approach is hindered by a lack of rigorous design methodologies that allow estim...

  20. INTEGRATING ANALYTICAL AEROELASTIC INSTABILITY ANALYSIS INTO DESIGN OPTIMIZATION OF AIRCRAFT WING STRUCTURES

    OpenAIRE

    , Pinar Acar

    2011-01-01

    Two analytical flutter solution approaches have been developed to optimize two and three dimensional aircraft wing structures with design criteria based on aeroelastic instabilities. The first approach uses open loop structural dynamics and stability analysis for a two dimensional wing model in order to obtain the critical speeds of flutter, divergence and control reversal for optimization process. The second approach involves a flutter solution for three dimensional wing structures by using ...

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

    OpenAIRE

    Ossmann, Daniel

    2015-01-01

    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. The Multidisciplinary Design Optimization of a Distributed Propulsion Blended-Wing-Body Aircraft

    OpenAIRE

    Ko, Yan-Yee Andy

    2003-01-01

    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 th...

  3. Revision Of The Aircraft Engines Preliminary Design Platform Of First Level

    OpenAIRE

    BENETHUILLERE, Quentin

    2014-01-01

    In the highly competitive aerospace industry, engine manufacturers must react very quickly and precisely to any demand emerging from aircraft manufacturers if they want to be positioned on the offer. This is especially true when answering to Requests For Information (RFI) based on preliminary design investigations of first level. In order to reduce the time needed to perform these costly operations while improving the performances achieved, Snecma wishes to develop tools for dimensioning the ...

  4. Advanced composites structural concepts and materials technologies for primary aircraft structures: Design/manufacturing concept assessment

    Science.gov (United States)

    Chu, Robert L.; Bayha, Tom D.; Davis, HU; Ingram, J. ED; Shukla, Jay G.

    1992-01-01

    Composite Wing and Fuselage Structural Design/Manufacturing Concepts have been developed and evaluated. Trade studies were performed to determine how well the concepts satisfy the program goals of 25 percent cost savings, 40 percent weight savings with aircraft resizing, and 50 percent part count reduction as compared to the aluminum Lockheed L-1011 baseline. The concepts developed using emerging technologies such as large scale resin transfer molding (RTM), automatic tow placed (ATP), braiding, out-of-autoclave and automated manufacturing processes for both thermoset and thermoplastic materials were evaluated for possible application in the design concepts. Trade studies were used to determine which concepts carry into the detailed design development subtask.

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

    Science.gov (United States)

    Quinlan, Jesse R.; Gern, Frank H.

    2016-01-01

    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.

  6. Application of modern control design methodology to oblique wing research aircraft

    Science.gov (United States)

    Vincent, James H.

    1991-01-01

    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.

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

    Science.gov (United States)

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

    2016-01-01

    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. Seal Design of the Aircraft Door%舱门密封件设计

    Institute of Scientific and Technical Information of China (English)

    渠涛

    2015-01-01

    密封件设计是飞机舱门设计的重要组成部分,其性能好坏关系着飞机的飞行安全,本文从密封件设计考虑因素、构型、性能验证等方面进行研究,给出设计密封件的一般考虑。%Seal Design is one of the most important parts of aircraft sealed cabin. The property of the seal is relative to the aircraft safety. It should be considerate that the seal environment factors, shape, and test should be studied.

  9. Assessment of dynamic effects on aircraft design loads: The landing impact case

    Science.gov (United States)

    Bronstein, Michael; Feldman, Esther; Vescovini, Riccardo; Bisagni, Chiara

    2015-10-01

    This paper addresses the potential benefits due to a fully dynamic approach to determine the design loads of a mid-size business jet. The study is conducted by considering the fuselage midsection of the DAEDALOS aircraft model with landing impact conditions. The comparison is presented in terms of stress levels between the novel dynamic approach and the standard design practice based on the use of equivalent static loads. The results illustrate that a slight reduction of the load levels can be achieved, but careful modeling of the damping level is needed. Guidelines for an improved load definition are discussed, and suggestions for future research activities are provided.

  10. Design and evaluation of a robust dynamic neurocontroller for a multivariable aircraft control problem

    Science.gov (United States)

    Troudet, T.; Garg, S.; Merrill, W.

    1992-01-01

    The design of a dynamic neurocontroller with good robustness properties is presented for a multivariable aircraft control problem. The internal dynamics of the neurocontroller are synthesized by a state estimator feedback loop. The neurocontrol is generated by a multilayer feedforward neural network which is trained through backpropagation to minimize an objective function that is a weighted sum of tracking errors, and control input commands and rates. The neurocontroller exhibits good robustness through stability margins in phase and vehicle output gains. By maintaining performance and stability in the presence of sensor failures in the error loops, the structure of the neurocontroller is also consistent with the classical approach of flight control design.

  11. Design study of structural concepts for an arrow-wing supersonic-cruise aircraft

    Science.gov (United States)

    Sakata, I. F.; Davis, G. W.; Robinson, J. C.; Yates, E. C., Jr.

    1975-01-01

    An analytical study was performed to determine the best structural approach for design of primary wing and fuselage structure of a Mach number 2.7 arrow-wing supersonic cruise aircraft. Concepts were evaluated considering near-term start-of-design. Emphasis was placed on the complex interactions between thermal stress, static aeroelasticity, flutter, fatigue and fail-safe design, static and dynamic loads, and the effects of variations in structural arrangements, concepts and materials on these interactions. Results indicate that a hybrid wing structure incorporating low-profile convex-beaded and honeycomb sandwich surface panels of titanium alloy 6Al-4V were the most efficient. The substructure includes titanium alloy spar caps reinforced with Boron-polyimide composites. The fuselage shell is a closed-hat stiffened skin and frame construction of titanium alloy 6Al-4V. This paper presents an executive summary of the study effort, and includes a discussion of the overall study logic, design philosophy and interaction between the analytical methods for supersonic cruise aircraft design.

  12. Advanced piloted aircraft flight control system design methodology. Volume 1: Knowledge base

    Science.gov (United States)

    Mcruer, Duane T.; Myers, Thomas T.

    1988-01-01

    The development of a comprehensive and electric methodology for conceptual and preliminary design of flight control systems is presented and illustrated. The methodology is focused on the design stages starting with the layout of system requirements and ending when some viable competing system architectures (feedback control structures) are defined. The approach is centered on the human pilot and the aircraft as both the sources of, and the keys to the solution of, many flight control problems. The methodology relies heavily on computational procedures which are highly interactive with the design engineer. To maximize effectiveness, these techniques, as selected and modified to be used together in the methodology, form a cadre of computational tools specifically tailored for integrated flight control system preliminary design purposes. While theory and associated computational means are an important aspect of the design methodology, the lore, knowledge and experience elements, which guide and govern applications are critical features. This material is presented as summary tables, outlines, recipes, empirical data, lists, etc., which encapsulate a great deal of expert knowledge. Much of this is presented in topical knowledge summaries which are attached as Supplements. The composite of the supplements and the main body elements constitutes a first cut at a a Mark 1 Knowledge Base for manned-aircraft flight control.

  13. Artificial Neural Networks Applications: from Aircraft Design Optimization to Orbiting Spacecraft On-board Environment Monitoring

    Science.gov (United States)

    Jules, Kenol; Lin, Paul P.

    2002-01-01

    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.

  14. Eigenvalue assignment based on standard characteristic polynominal in design of aircraft control systems

    Science.gov (United States)

    Li, Aijun; Lv, Yang; Wang, Changqing

    2008-10-01

    Design method of eigenvalue assignment based on standard characteristic polynomial, as well as mathematical solving process of the method, is proposed in this paper so as to resolve the uncertainty of ideal eigenvalue choice in modern control theory and the difficultly in engineering implementation of modern control system design methods. Longitudinal stability holding control system of an aircraft was designed and simulated by employing proposed method. Dynamic character and robust performance simulation of the system are given. Simulation results show that the method achieves the control quality and has better robustness than another method. There is only one design parameter which is easy to calculate. So, the method is characterized as simple design, logical structure, easy programming and convenient for engineering implementation.

  15. Aircraft ride quality controller design using new robust root clustering theory for linear uncertain systems

    Science.gov (United States)

    Yedavalli, R. K.

    1992-01-01

    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.

  16. Application of modern control theory to the design of optimum aircraft controllers

    Science.gov (United States)

    Power, L. J.

    1973-01-01

    A procedure is described for synthesis of optimal aircraft control systems by application of the concepts of optimal control theory to time-invariant linear systems with quadratic performance criteria. Essential in this synthesis procedure is the solution of the Riccati matrix equation which results in a constant linear feedback control law for an output regulator which maintains a plant in an equilibrium in the presence of impulse disturbances. An algorithm is derived for designing maneuverable output regulators with selected state variables for feedback.

  17. Design and evaluation of an onboard computer-based information system for aircraft

    Science.gov (United States)

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

    1982-01-01

    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.

  18. Vehicle Sketch Pad: a Parametric Geometry Modeler for Conceptual Aircraft Design

    Science.gov (United States)

    Hahn, Andrew S.

    2010-01-01

    The conceptual aircraft designer is faced with a dilemma, how to strike the best balance between productivity and fidelity? Historically, handbook methods have required only the coarsest of geometric parameterizations in order to perform analysis. Increasingly, there has been a drive to upgrade analysis methods, but these require considerably more precise and detailed geometry. Attempts have been made to use computer-aided design packages to fill this void, but their cost and steep learning curve have made them unwieldy at best. Vehicle Sketch Pad (VSP) has been developed over several years to better fill this void. While no substitute for the full feature set of computer-aided design packages, VSP allows even novices to quickly become proficient in defining three-dimensional, watertight aircraft geometries that are adequate for producing multi-disciplinary meta-models for higher order analysis methods, wind tunnel and display models, as well as a starting point for animation models. This paper will give an overview of the development and future course of VSP.

  19. Linear Quadratic Tracking Design for a Generic Transport Aircraft with Structural Load Constraints

    Science.gov (United States)

    Burken, John J.; Frost, Susan A.; Taylor, Brian R.

    2011-01-01

    When designing control laws for systems with constraints added to the tracking performance, control allocation methods can be utilized. Control allocations methods are used when there are more command inputs than controlled variables. Constraints that require allocators are such task as; surface saturation limits, structural load limits, drag reduction constraints or actuator failures. Most transport aircraft have many actuated surfaces compared to the three controlled variables (such as angle of attack, roll rate & angle of side slip). To distribute the control effort among the redundant set of actuators a fixed mixer approach can be utilized or online control allocation techniques. The benefit of an online allocator is that constraints can be considered in the design whereas the fixed mixer cannot. However, an online control allocator mixer has a disadvantage of not guaranteeing a surface schedule, which can then produce ill defined loads on the aircraft. The load uncertainty and complexity has prevented some controller designs from using advanced allocation techniques. This paper considers actuator redundancy management for a class of over actuated systems with real-time structural load limits using linear quadratic tracking applied to the generic transport model. A roll maneuver example of an artificial load limit constraint is shown and compared to the same no load limitation maneuver.

  20. Design of an airborne Fourier transform visible hyperspectral imaging system for light aircraft environmental remote sensing

    Science.gov (United States)

    Otten, Leonard John, III; Butler, Eugene W.; Rafert, Bruce; Sellar, R. Glenn

    1995-06-01

    Kestrel Corporation and the Florida Institute of Technology have designed, and are now manufacturing, a Fourier transform visible hyperspectral imager system for use in a single engine light aircraft. The system is composed of a Sagnac-based interferometer optical subsystem, a data management system, and an aircraft attitude and current position sybsystem. The system is designed to have better than 5 nm spectral resolution at 450 nm, operates over the 440 nm to 1150 nm spectral band and has a 2D spatial resolution of 0.8 mrad. An internal calibration source is recorded with every frame of data to retain radiometric accuracy. The entire system fits into a Cessna 206 and uses a conventional downward looking view port located in the baggage compartment. During operation, data are collected at a rate of 15 Mbytes per second and stored direct to a disk array. Data storage has been sized to accommodate 56 minutes of observations. Designed for environmental mapping, this Fourier transform imager has uses in emergency response and military operations.

  1. Design for Manufacturing of Composite Structures for Commercial Aircraft : The Development of a DFM strategy at SAAB Aerostructures

    OpenAIRE

    Andersson, Frida; Hagqvist, Astrid; Sundin, Erik; Björkman, Mats

    2014-01-01

    Within the aircraft industry, the use of composite materials such as carbon fiber reinforced plastics (CFRPs) is steadily increasing, especially in structural parts. Manufacturability needs to be considered in aircraft design to ensure a cost-effective manufacturing process. The aim of this paper is to describe the development of a new strategy for how SAAB Aerostructures addressing manufacturability issues during the development of airframe composite structures. Through literature review, be...

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

    OpenAIRE

    Tian, F.N.

    2015-01-01

    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 performance by reducing the aircraft weight and by a lower overall energy requirement for the systems. The vision for the future is to ultimately replace all systems with electrical systems and even to repl...

  3. Output feedback non-linear decoupled control synthesis and observer design for manoeuvring aircraft

    Science.gov (United States)

    Singh, S. N.; Schy, A. A.

    1980-01-01

    A study of the applicability of nonlinear decoupling theory to the design of control systems using output feedback for maneuvering aircraft is presented. The response variables chosen for decoupled control were angular velocity components along roll, pitch, and yaw axes, angle of attack (p), and angle of sideslip, using aileron, rudder, and elevator controls. An observer design for a class of nonlinear systems was presented and this method was used to estimate angle of attack and sideslip; an approximate observer was obtained by neglecting derivatives of p and aileron deflection angles and it was used in a simulation study. A simulation study showed that precise rapid combined lateral and longitudinal maneuvers can be performed; it was also demonstrated that a bank-angle-command outer loop could be designed for precise bank angles changes and simultaneous large lift maneuvers.

  4. Design and piloted simulation evaluation of integrated flight/propulsion controls for STOVL aircraft

    Science.gov (United States)

    Franklin, James A.; Engelland, Shawn A.

    1991-01-01

    Integrated flight/propulsion control systems have been designed for operation of STOVL aircraft over the low speed powered-lift flight envelope. The control system employs command modes for attitude, flightpath angle and flightpath acceleration during transition, and translational velocity command for hover and vertical landing. The command modes and feedback control are implemented in the form of a state-rate feedback implicit model follower to achieve the desired flying qualities and to suppress the effects of external disturbances and variations in the aircraft characteristics over the low speed envelope. A nonlinear inverse system was used to translate the output from these commands and feedback control into commands for the various aerodynamic and propulsion control effectors that are employed in powered-lift flight. Piloted evaluations of these STOVL integrated control designs have been conducted on Ames Research Center's Vertical Motion Simulator to assess flying qualities over the low-speed flight envelope. Results indicate that Level 1 flying qualities are achieved with this control system concept for each of these low-speed operations over a wide range of wind, atmospheric turbulence, and visibility conditions.

  5. Optimal design of a composite wing structure for a flying-wing aircraft subject to multi-constraint

    OpenAIRE

    Xu, Rongxin

    2012-01-01

    This thesis presents a research project and results of design and optimization of a composite wing structure for a large aircraft in flying wing configuration. The design process started from conceptual design and preliminary design, which includes initial sizing and stressing followed by numerical modelling and analysis of the wing structure. The research was then focused on the minimum weight optimization of the /composite wing structure /subject to multiple design /constraints. The modelli...

  6. AP1000R design robustness against extreme external events - Seismic, flooding, and aircraft crash

    International Nuclear Information System (INIS)

    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 AP1000R 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 containment vessel which is

  7. Dual concrete containment design with optimal resistance to aircraft impact and earthquake. Design sensitivity supported by mathematical models

    International Nuclear Information System (INIS)

    As per current practice in most of the European countries, protection against aircraft crash is required. Notwithstanding some national regulatory differences, this protection is in general very expensive. Therefore an optimisation design process could be very advantageous. In fact the secondary containment design has to satisfy both impact and seismic requirements, as in many cases earthquake resistance is a lower limit for the thickness. The final optimal size is a compromise between the two requirements and it guarantees at the same time both the cheapest global configuration and the minimum impact on the existing design. The results of a large numerical analysis programme is presented, based on the most recent experimental data and computer codes. (author). 9 refs., 3 figs., 3 tabs

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

    Science.gov (United States)

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

    2009-01-01

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

  9. Structural Design Optimization of a Tiltrotor Aircraft Composite Wing to Enhance Whirl Flutter Stability

    DEFF Research Database (Denmark)

    Kim, Taeseong; Kim, Jaehoon; Shin, Sang Joon;

    2013-01-01

    In order to enhance the aeroelastic stability of a tiltrotor aircraft, a structural optimization framework is developed by applying a multi-level optimization approach. Each optimization level is designed to achieve a different purpose; therefore, relevant optimization schemes are selected for each...... level. Enhancement of the aeroelastic stability is selected as an objective in the upper-level optimization. This is achieved by seeking the optimal structural properties of a composite wing, including its mass, vertical, chordwise, and torsional stiffness. In the upper-level optimization, the response...... surface method (RSM), is selected. On the other hand, lower-level optimization seeks to determine the local detailed cross-sectional parameters, such as the ply orientation angles and ply thickness, which are relevant to the wing structural properties obtained at the upper-level. To avoid manufacturing...

  10. 飞机天线系统EMC设计%EMC design of aircraft antenna system

    Institute of Scientific and Technical Information of China (English)

    魏亮; 李峰; 王涛涛

    2012-01-01

    飞机天线系统EMC设计的主题思想就是为了保证所有机载设备都能够相互无干扰地调和工作,即各天线在能够正常工作的同时,不会干扰其他天线的工作,还要兼顾天线的性能和工程安装要求,满足整机机载设备正常工作,任务设备也能够正常工作.采用仿真软件进行天线系统电磁兼容的仿真计算后制作了1∶1飞机壳体,进行了天线布局的缩比模型模拟测试,得出了整个飞机的天线布局方案.并提出当出现天线间隔离度太小,可能导致相互间干扰时,从系统层面上考虑分时或分频工作,而需要同时工作的不同频率的天线,应在系统链路上附加滤波器等措施,提高天线发射机对谐波和三阶交调系数的抑制.%EMC design purpose of the aircraft antenna system is to ensure that all the airborne equipments work normally without interaction interference. In addition, the design takes into account of the antenna performance and requirements of the antenna engineering installation, so as to meet the normal work of other airborne equipments. The simulation software is adopted to perform the simulation calculation of the electromagnetic compatibility of the antenna system in this paper. A 1:1 aircraft shell was produced to carry out the scale-reduced model simulation testing for the antenna layout. The scheme of the entire aircraft antenna layout was obtained. A conclusion that when the isolation degree is too small. it is supposed that the in teraction interference may occur. The time-shearing and frequency demultiplication were considered in the system level. When more antennas work simultaneously at different frequencies, an additional filter should be put into the periodic line of the system or other measures should be taken to improve the inhibition ability of antenna transmitter in the harmonic and third order intermodulation coefficient.

  11. Design and test of an aircraft deployable sensor for the Antarctic peninsula

    Science.gov (United States)

    Jones, D.; Robinson, C.; Causton, B.; Gudmundsson, H.

    2012-04-01

    There remains large areas of scientific interest in the Antarctic that are not instrumented. These include highly dynamic ice sheets and glaciers that are difficult or impossible to reach by ground via overland treks, due to heavy crevassing, or through aircraft landing. We have developed an alternative strategy for instrumenting these regions: a sensor probe that can be dropped from aircraft , partially bury itself in the snow whilst protruding high above the surface to ensure a long operating life. Our probe is shaped like a 2.5m long missile that can be dropped through a standard sonar-buoy launch tube. In order to achieve a consistent impact depth in different snow densities the case is fitted with fold-out fins one metre from the nose cone. This ensures a large step-change in impact surface area when one metre of the device is embedded in the snow. A disk-gap-band parachute design reduces the impact speed, improves the angle of impact while damping probe oscillations. To prevent strong winds from knocking the sensor over the parts of the sensor that protrude above the snow are narrow, the parts of the sensor that are buried are much wider and the parachute separates from the sensor after impact. The sensor is cheap to make (approximately £ 500) and has a minimal environmental impact. An extensive series of tests conducted this season about the Rothera research station and the forward operating base Sky Blu have validated this sensor design in different snow and weather conditions. We intend to deploy a network of these sensors across Pine Island Glacier next year.

  12. An Interactive Method of Characteristics Java Applet to Design and Analyze Supersonic Aircraft Nozzles

    Science.gov (United States)

    Benson, Thomas J.

    2014-01-01

    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.

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

    Science.gov (United States)

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

    2014-10-01

    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. Cascade Optimization Strategy with Neural Network and Regression Approximations Demonstrated on a Preliminary Aircraft Engine Design

    Science.gov (United States)

    Hopkins, Dale A.; Patnaik, Surya N.

    2000-01-01

    A preliminary aircraft engine design methodology is being developed that utilizes a cascade optimization strategy together with neural network and regression approximation methods. The cascade strategy employs different optimization algorithms in a specified sequence. The neural network and regression methods are used to approximate solutions obtained from the NASA Engine Performance Program (NEPP), which implements engine thermodynamic cycle and performance analysis models. The new methodology is proving to be more robust and computationally efficient than the conventional optimization approach of using a single optimization algorithm with direct reanalysis. The methodology has been demonstrated on a preliminary design problem for a novel subsonic turbofan engine concept that incorporates a wave rotor as a cycle-topping device. Computations of maximum thrust were obtained for a specific design point in the engine mission profile. The results (depicted in the figure) show a significant improvement in the maximum thrust obtained using the new methodology in comparison to benchmark solutions obtained using NEPP in a manual design mode.

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

    NARCIS (Netherlands)

    Tian, F.N.

    2015-01-01

    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

  16. Aircraft wing structural design optimization based on automated finite element modelling and ground structure approach

    Science.gov (United States)

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

    2016-01-01

    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.

  17. Pilot Designed Aircraft Displays in General Aviation: An Exploratory Study and Analysis

    Science.gov (United States)

    Conaway, Cody R.

    From 2001-2011, the General Aviation (GA) fatal accident rate remained unchanged (Duquette & Dorr, 2014) with an overall stagnant accident rate between 2004 and 2013. The leading cause, loss of control in flight (NTSB, 2015b & 2015c) due to pilot inability to recognize approach to stall/spin conditions (NTSB, 2015b & 2016b). In 2013, there were 1,224 GA accidents in the U.S., accounting for 94% of all U.S. aviation accidents and 90% of all U.S. aviation fatalities that year (NTSB, 2015c). Aviation entails multiple challenges for pilots related to task management, procedural errors, perceptual distortions, and cognitive discrepancies. While machine errors in airplanes have continued to decrease over the years, human error still has not (NTSB, 2013). A preliminary analysis of a PC-based, Garmin G1000 flight deck was conducted with 3 professional pilots. Analyses revealed increased task load, opportunities for distraction, confusing perceptual ques, and hindered cognitive performance. Complex usage problems were deeply ingrained in the functionality of the system, forcing pilots to use fallible work arounds, add unnecessary steps, and memorize knob turns or button pushes. Modern computing now has the potential to free GA cockpit designs from knobs, soft keys, or limited display options. Dynamic digital displays might include changes in instrumentation or menu structuring depending on the phase of flight. Airspeed indicators could increase in size to become more salient during landing, simultaneously highlighting pitch angle on Attitude Indicators and automatically decluttering unnecessary information for landing. Likewise, Angle-of-Attack indicators demonstrate a great safety and performance advantage for pilots (Duquette & Dorr, 2014; NTSB, 2015b & 2016b), an instrument typically found in military platforms and now the Icon A5, light-sport aircraft (Icon, 2016). How does the design of pilots' environment---the cockpit---further influence their efficiency and

  18. Science requirements and feasibility/design studies of a very-high-altitude aircraft for atmospheric research

    Science.gov (United States)

    Russell, Philip B.; Lux, David P.; Reed, R. Dale; Loewenstein, Max; Wegener, Steven

    1991-01-01

    The advantages and shortcomings of currently available aircraft for use in very high altitude missions to study such problems as polar ozone or stratosphere-troposphere exchange pose the question of whether to develop advanced aircraft for atmospheric research. To answer this question, NASA conducted a workshop to determine science needs and feasibility/design studies to assess whether and how those needs could be met. It was determined that there was a need for an aircraft that could cruise at an altitude of 30 km with a range of 6,000 miles with vertical profiling down to 10 km and back at remote points and carry a payload of 3,000 lbs.

  19. Preliminary Design of the Low Speed Propulsion Air Intake of the LAPCAT-MR2 Aircraft

    Science.gov (United States)

    Meerts, C.; Steelant, J.; Hendrick, P.

    2011-08-01

    A supersonic air intake has been designed for the low speed propulsion system of the LAPCAT-MR2 aircraft. Development has been based on the XB-70 aircraft air intake which achieves extremely high performances over a wide operation range through the combined use of variable geometry and porous wall suction for boundary layer control. Design of the LAPCAT-MR2 intake has been operated through CFD simulations using DLR TAU-Code (perfect gas model - Menter SST turbulence model). First, a new boundary condition has been validated into the DLR TAU-Code (perfect gas model) for porous wall suction modelling. Standard test cases have shown surprisingly good agreement with both theoretical predictions and experimental results. Based upon this validation, XB-70 air intake performances have been assessed through CFD simulations over the subsonic, transonic and supersonic operation regions and compared to available flight data. A new simulation strategy was deployed avoiding numerical instabilities when initiating the flow in both transonic and supersonic operation modes. First, the flow must be initiated with a far field Mach number higher than the target flight Mach number. Additionally, the inlet backpressure may only be increased to its target value once the oblique shock pattern downstream the intake compression ramps is converged. Simulations using that strategy have shown excellent agreement with in-flight measurements for both total pressure recovery ratio and variable geometry schedule prediction. The demarcation between stable and unstable operation could be well reproduced. Finally, a modified version of the XB-70 air intake has been integrated in the elliptical intake on the LAPCAT vehicle. Operation of this intake in the LAPCAT-MR2 environment is under evaluation using the same simulation strategy as the one developed for the XB-70. Performances are assessed at several key operation points to assess viability of this design. This information will allow in a next

  20. A domain-specific design architecture for composite material design and aircraft part redesign

    Science.gov (United States)

    Punch, W. F., III; Keller, K. J.; Bond, W.; Sticklen, J.

    1992-01-01

    Advanced composites have been targeted as a 'leapfrog' technology that would provide a unique global competitive position for U.S. industry. Composites are unique in the requirements for an integrated approach to designing, manufacturing, and marketing of products developed utilizing the new materials of construction. Numerous studies extending across the entire economic spectrum of the United States from aerospace to military to durable goods have identified composites as a 'key' technology. In general there have been two approaches to composite construction: build models of a given composite materials, then determine characteristics of the material via numerical simulation and empirical testing; and experience-directed construction of fabrication plans for building composites with given properties. The first route sets a goal to capture basic understanding of a device (the composite) by use of a rigorous mathematical model; the second attempts to capture the expertise about the process of fabricating a composite (to date) at a surface level typically expressed in a rule based system. From an AI perspective, these two research lines are attacking distinctly different problems, and both tracks have current limitations. The mathematical modeling approach has yielded a wealth of data but a large number of simplifying assumptions are needed to make numerical simulation tractable. Likewise, although surface level expertise about how to build a particular composite may yield important results, recent trends in the KBS area are towards augmenting surface level problem solving with deeper level knowledge. Many of the relative advantages of composites, e.g., the strength:weight ratio, is most prominent when the entire component is designed as a unitary piece. The bottleneck in undertaking such unitary design lies in the difficulty of the re-design task. Designing the fabrication protocols for a complex-shaped, thick section composite are currently very difficult. It is in

  1. Optimal design of a multifunctional aircraft skin with energy harvesting via entropy generation minimization. Paper no. IGEC-1-ID19

    International Nuclear Information System (INIS)

    The Entropy Generation Minimization (EGM) approach is applied to the optimal design of a new integrated radar aircraft skin, which both meets the requisite structural needs and provides a pathway for the waste heat from inefficient radar devices. Thermoelectric devices, sandwiched between the skin and the radar devices for the purpose of harvesting some of the waste heat to be rejected to the ambient, are considered in the analysis. A composite skin, comprised of a novel lightweight carbon foam with cylindrical carbon nanofiber/polymer 'arteries' through the thickness of the skin, is considered. The EGM approach, applied to the overall mission of the aircraft, is utilized to determine the optimal skin thickness, as well as artery diameter and spacing. The optimal configuration determined corresponds to the maximum energy harvesting condition and minimal fuel use, but surprisingly, does not necessarily correspond to a minimal skin mass. The latter ordinarily would be the focus of aircraft designers. As importantly, the results show the benefit of the EGM approach to even the design of the microstructure of an aircraft component, and thus, it can be inferred to any system which affects energy use and distribution. (author)

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

    Directory of Open Access Journals (Sweden)

    Yu Wang

    2015-01-01

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

    Directory of Open Access Journals (Sweden)

    Chromek L.

    2016-06-01

    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.

  4. Design of an aircraft landing system using dual-frequency GNSS

    Science.gov (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

  5. A Generic Inner-Loop Control Law Structure for Six-Degree-of-Freedom Conceptual Aircraft Design

    Science.gov (United States)

    Cox, Timothy H.; Cotting, M. Christopher

    2005-01-01

    A generic control system framework for both real-time and batch six-degree-of-freedom simulations is presented. This framework uses a simplified dynamic inversion technique to allow for stabilization and control of any type of aircraft at the pilot interface level. The simulation, designed primarily for the real-time simulation environment, also can be run in a batch mode through a simple guidance interface. Direct vehicle-state acceleration feedback is required with the simplified dynamic inversion technique. The estimation of surface effectiveness within real-time simulation timing constraints also is required. The generic framework provides easily modifiable control variables, allowing flexibility in the variables that the pilot commands. A direct control allocation scheme is used to command aircraft effectors. Primary uses for this system include conceptual and preliminary design of aircraft, when vehicle models are rapidly changing and knowledge of vehicle six-degree-of-freedom performance is required. A simulated airbreathing hypersonic vehicle and simulated high-performance fighter aircraft are used to demonstrate the flexibility and utility of the control system.

  6. A framework for the design of a voice-activated, intelligent, and hypermedia-based aircraft maintenance manual

    Science.gov (United States)

    Patankar, Manoj Shashikant

    Federal Aviation Regulations require Aviation Maintenance Technicians (AMTs) to refer to approved maintenance manuals when performing maintenance on airworthy aircraft. Because these manuals are paper-based, larger the size of the aircraft, more cumbersome are the manuals. Federal Aviation Administration (FAA) recognized the difficulties associated with the use of large manuals and conducted studies on the use of electronic media as an alternative to the traditional paper format. However, these techniques do not employ any artificial intelligence technologies and the user interface is limited to either a keyboard or a stylus pen. The primary emphasis of this research was to design a generic framework that would allow future development of voice-activated, intelligent, and hypermedia-based aircraft maintenance manuals. A prototype (VIHAMS-Voice-activated, Intelligent, and Hypermedia-based Aircraft Maintenance System) was developed, as a secondary emphasis, using the design and development techniques that evolved from this research. An evolutionary software design approach was used to design the proposed framework and the structured rapid prototyping technique was used to produce the VIHAMS prototype. VoiceAssist by Creative Labs was used to provide the voice interface so that the users (AMTs) could keep their hands free to work on the aircraft while maintaining complete control over the computer through discrete voice commands. KnowledgePro for Windows sp{TM}, an expert system shell, provided "intelligence" to the prototype. As a result of this intelligence, the system provided expert guidance to the user. The core information contained in conventional manuals was available in a hypermedia format. The prototype's operating hardware included a notebook computer with a fully functional audio system. An external microphone and the built-in speaker served as the input and output devices (along with the color monitor), respectively. Federal Aviation Administration

  7. 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

    2012-01-01

    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.

  8. Weasel works SA-150: Design study of a 100 to 150 passenger transport aircraft

    Science.gov (United States)

    Alkema, Kevin; Comeaux, Michael; Gilbert, Timothy; Para, Victor; Toepfer, George

    1993-01-01

    As the year 2000 rapidly approaches, the airlines are faced with an extremely competitive and environmentally restrictive marketplace. In order to survive, commercial air carriers will need to find new ways to lower their direct operating costs, increase load factors and comply with tightening federal and international constraints. The SA-150 has been designed to meet these demands by focusing on the areas of aerodynamic efficiency, an improved level of passenger comfort, and a limited application of advanced technology. The SA-150 has been optimized for a 500 nmi. mission to help the airlines meet the challenges of the short haul, quick turnaround flight. With a maximum capacity of 124 passengers, and full baggage, the SA-150 is also capable of covering a range of 1500 nmi. This additional range capability will provide the airlines with flexibility when scheduling their routes. The aircraft features a 'V' tail, fly-by-wire system and is powered by two turbofans mounted under a twelve aspect ratio wing. The SA-150 will have an initial production run of 800 units and have a purchase price of $37.7 million in 1993 dollars.

  9. The Application of Decomposition to the Large Scale Synthesis/Design Optimization of Aircraft Energy Systems

    Directory of Open Access Journals (Sweden)

    Michael R. von Spakovsky

    2001-06-01

    Full Text Available An application of a decomposition approach for large-scale optimization (i.e., the Iterative Local-Global Optimization (ILGO approach developed by Muñoz and von Spakovsky (2001 is presented. The synthesis / design optimization of a turbofan engine coupled to an environmental control system for a military aircraft was carried out. The problem was solved for a given mission (i.e. a load / environmental profile composed of fifteen segments. The number of decision (independent variables both discrete and continuous for this highly non-linear optimization problem was one hundred fifty-three. Both the thermodynamic and physical (weight and volume simulations were carried out using state-of-the art tools. Three objective functions were investigated: take-off gross weight, mission fuel consumption and total cost, and no observable differences were found in the final results. In addition to the mathematical foundations for global convergence presented in Muñoz and von Spakovsky (2000b, 2001, convergence was validated numerically by solving the entire mixed-integer non-linear programming (MINLP problem without decomposition using a subset of the independent variables. The constant value of the shadow prices (or linear behavior of the Optimum Response Surface – OSR played a major role in global convergence of the ILGO approach.

  10. Structural development of laminar flow control aircraft chordwise wing joint designs

    Science.gov (United States)

    Fischler, J. E.; Jerstad, N. M.; Gallimore, F. H., Jr.; Pollard, T. J.

    1989-01-01

    For laminar flow to be achieved, any protuberances on the surface must be small enough to avoid transition to turbulent flow. However, the surface must have joints between the structural components to allow assembly or replacement of damaged parts, although large continuous surfaces can be utilized to minimize the number the number of joints. Aircraft structural joints usually have many countersunk bolts or rivets on the outer surface. To maintain no mismatch on outer surfaces, it is desirable to attach the components from the inner surface. It is also desirable for the panels to be interchangeable, without the need for shims at the joint, to avoid surface discontinuities that could cause turbulence. Fabricating components while pressing their outer surfaces against an accurate mold helps to ensure surface smoothness and continuity at joints. These items were considered in evaluating the advantages and disadvantages of the joint design concepts. After evaluating six design concepts, two of the leading candidates were fabricated and tested using many small test panels. One joint concept was also built and tested using large panels. The small and large test panel deflections for the leading candidate designs at load factors up to +1.5 g's were well within the step and waviness requirements for avoiding transition.The small panels were designed and tested for compression and tension at -65 F, at ambient conditions, and at 160 F. The small panel results for the three-rib and the sliding-joint concepts indicated that they were both acceptable. The three-rib concept, with tapered splice plates, was considered to be the most practical. A modified three-rib joint that combined the best attributes of previous candidates was designed, developed, and tested. This improved joint met all of the structural strength, surface smoothness, and waviness criteria for laminar flow control (LFC). The design eliminated all disadvantages of the initial three-rib concept except for

  11. Active Flow Control with Adaptive Design Techniques for Improved Aircraft Safety Project

    Data.gov (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...

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

    Science.gov (United States)

    Dyson, Rodger W.

    2016-01-01

    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.

  13. Decomposition with Thermoeconomic Isolation Applied to the Optimal Synthesis/Design of an Advanced Tactical Aircraft System

    Directory of Open Access Journals (Sweden)

    Michael R. von Spakovsky

    2003-09-01

    Full Text Available A decomposition methodology based on the concept of “thermoeconomic isolation” and applied to the synthesis/design and operational optimization of an advanced tactical fighter aircraft is the focus of this paper. The most promising set of aircraft sub-system configurations, based on both an energy integration analysis and aerodynamic performance, were first developed and detailed thermodynamic, geometric, physical, and aerodynamic models at both design and off-design were formulated and implemented. Conceptual, time, and physical decomposition were then applied to the synthesis/design and operational optimization of the aircraft system. The physical decomposition strategy used, called Iterative Local-Global Optimization (ILGO, was developed by Muñoz and von Spakovsky (2001a,b and has been applied to a number of complex stationary and transportation applications. This decomposition strategy is the first to successfully closely approach the theoretical condition of “thermoeconomic isolation” when applied to highly complex, highly dynamic non-linear systems.

  14. Flying qualities and flight control system design for a fly-by-wire transport aircraft

    OpenAIRE

    Gautrey, Jim

    1998-01-01

    Fly-by-wire flight control systems are becoming more common in both civil and military aircraft. These systems give many benefits, but also present a new set of problems due to their increased complexity compared to conventional systems and the larger choice of options that they provide. The work presented here considers the application of fly-by-wire to a generic regional transport aircraft. The flying qualities criteria used for typical flying qualities evaluations are described...

  15. Designing an Interactive Local and Global Decision Support System for Aircraft Carrier Deck Scheduling

    OpenAIRE

    Ryan, Jason Christopher; Cummings, M.L.; Roy, Nicholas; Banerjee, Ashis; Schulte, Axel

    2011-01-01

    In the near future, unmanned aerial vehicles will become part of the naval aircraft carrier operating environment. This will add significant complexity to an already highly constrained and dangerous environment. The move towards a shared manned-unmanned environment with an increasing operational tempo in a reduced manning environment will mean more automation is needed in the planning and scheduling of aircraft, ground vehicles, and crew in these complex environments. However, whi...

  16. Multiple Criteria Decision Analysis Techniques in Aircraft Design and Evaluation Processes

    OpenAIRE

    Sun, Xiaoqian

    2012-01-01

    Air transportation systems are complex, interdisciplinary integrated systems, because there are large numbers of components with different characteristics. It is challenging to assess new technology in complex, interdisciplinary integrated systems, such as air transportation systems. The focus of this research is one element in complex air transportation systems: aircraft. The success of an aircraft is no longer dominated by economic criteria. Several other criteria, such as environmental asp...

  17. The Use of the 2nd Law as a Potential Design Tool for Aircraft Air Frame Subsystems

    Directory of Open Access Journals (Sweden)

    David J. Moorhouse

    2006-12-01

    Full Text Available This paper presents the modeling of the irreversible thermodynamics of the Air Frame Subsystem as a component of integrated aircraft design/synthesis. Entropy calculation procedures for complicated geometries in curvilinear coordinates are described, including the effects of turbulence. Both inviscid and viscous calculations are reported and the contributions of the various terms in the entropy equation are investigated. The procedure is validated and then extended to the calculation of entropy generation associated with flow over the B747200 aircraft. Results show that most of the entropy generation is due to turbulence. The viscous dissipation term in the entropy equation dominates compared to the heat transfer term. The implications of the results for design improvement are briefly discussed.

  18. Design and initial application of the extended aircraft interrogation and display system: Multiprocessing ground support equipment for digital flight systems

    Science.gov (United States)

    Glover, Richard D.

    1987-01-01

    A pipelined, multiprocessor, general-purpose ground support equipment for digital flight systems has been developed and placed in service at the NASA Ames Research Center's Dryden Flight Research Facility. The design is an outgrowth of the earlier aircraft interrogation and display system (AIDS) used in support of several research projects to provide engineering-units display of internal control system parameters during development and qualification testing activities. The new system, incorporating multiple 16-bit processors, is called extended AIDS (XAIDS) and is now supporting the X-29A forward-swept-wing aircraft project. This report describes the design and mechanization of XAIDS and shows the steps whereby a typical user may take advantage of its high throughput and flexible features.

  19. An assessment of tailoring of lightning protection design requirements for a composite wing structure on a metallic aircraft

    Science.gov (United States)

    Harwood, T. L.

    1991-01-01

    The Navy A-6E aircraft is presently being modified with a new wing which uses graphite/epoxy structures and substructures around a titanium load-bearing structure. The ability of composites to conduct electricity is less than that of aluminum. This is cause for concern when the wing may be required to conduct large lightning currents. The manufacturer attempted to solve lightning protection issues by performing a risk assessment based on a statistical approach which allows relaxation of the wing lightning protection design levels over certain locations of the composite wing. A sensitivity study is presented designed to define the total risk of relaxation of the design levels.

  20. Design of a small personal air monitor and its application in aircraft.

    Science.gov (United States)

    van Netten, Chris

    2009-01-15

    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 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). PMID:18801557

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

    Science.gov (United States)

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

    1973-01-01

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

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

    Science.gov (United States)

    Treon, S. L.

    1979-01-01

    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.

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

    OpenAIRE

    Luís M. B. C. Campos

    2015-01-01

    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 li...

  4. A Global Optimization Approach Integrating Low Frequency Switching Harmonics Standard for Electric Actuators Design in Aircraft Electrical Networks: Harmonics/Weight Optimization

    OpenAIRE

    Hrigua, Slim; Wurtz, Frédéric; Enciu, Petre; Brunotte, Xavier; Delhommais, Mylène

    2015-01-01

    In aircraft applications, ensuring the power quality of the electrical system is one of the critical constraints during network equipment design. This task must be done in accordance with additional constraints like the global weight, cost and volume. In order to prevent high level disturbances in aircraft networks, international standards have fixed the conducted EMI levels that power converters are allowed to emit. On the other hand, respecting these standards at the design step requires an...

  5. Aircraft Design Considerations to Meet One Engine Inoperative (OEI) Safety Requirements

    Science.gov (United States)

    Scott, Mark W.

    2012-01-01

    Commercial airlines are obligated to operate such that an aircraft can suffer an engine failure at any point in its mission and terminate the flight without an accident. Only minimal aircraft damage is allowable, such as brake replacement due to very heavy application, or an engine inspection and/or possible removal due to use of an emergency rating. Such performance criteria are often referred to as zero exposure, referring to zero accident exposure to an engine failure. The critical mission segment for meeting one engine inoperative (OEI) criteria is takeoff. For a given weight, wind, and ambient condition, fixed wing aircraft require a balanced field length. This is the longer of the distance to take off if an engine fails at a predetermined critical point in the takeoff profile, or the distance to reject the takeoff and brake to a stop. Rotorcraft have requirements for horizontal takeoff procedures that are equivalent to a balanced field length requirements for fixed wing aircraft. Rotorcraft also perform vertical procedures where no runway or heliport distance is available. These were developed primarily for elevated heliports as found on oil rigs or rooftops. They are also used for ground level operations as might be found at heliports at the end of piers or other confined areas.

  6. Lightning effects on aircraft

    Science.gov (United States)

    1977-01-01

    Direct and indirect effects of lightning on aircraft were examined in relation to aircraft design. Specific trends in design leading to more frequent lightning strikes were individually investigated. These trends included the increasing use of miniaturized, solid state components in aircraft electronics and electric power systems. A second trend studied was the increasing use of reinforced plastics and other nonconducting materials in place of aluminum skins, a practice that reduces the electromagnetic shielding furnished by a conductive skin.

  7. Decomposition with thermoeconomic isolation applied to the optimal synthesis/design and operation of an advanced tactical aircraft system

    Energy Technology Data Exchange (ETDEWEB)

    Rancruel, Diego F. [Center for Energy Systems Research, Department of Mechanical Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24060 (United States); Spakovsky, Michael R. von [Center for Energy Systems Research, Department of Mechanical Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24060 (United States)]. E-mail: vonspako@vt.edu

    2006-12-15

    A decomposition methodology based on the concept of 'thermoeconomic isolation' and applied to the synthesis/design and operational optimization of an advanced tactical fighter aircraft is the focus of this paper. The total system is composed of six sub-systems of which five participate with degrees of freedom (493) in the optimization. They are the propulsion sub-system (PS), the environmental control sub-system (ECS), the fuel loop subsystem (FLS), the vapor compression and Polyalphaolefin (PAO) loops sub-system (VC/PAOS), and the airframe sub-system (AFS). The sixth subsystem comprises the expendable and permanent payloads as well as the equipment group. For each of the first five, detailed thermodynamic, geometric, physical, and aerodynamic models at both design and off-design were formulated and implemented. The most promising set of aircraft sub-system and system configurations were then determined based on both an energy integration and aerodynamic performance analysis at each stage of the mission (including the transient ones). Conceptual, time, and physical decomposition were subsequently applied to the synthesis/design and operational optimization of these aircraft configurations as well as to the highly dynamic process of heat generation and dissipation internal to the subsystems. The physical decomposition strategy used (i.e. Iterative Local-Global Optimization-ILGO) is the first to successfully closely approach the theoretical condition of 'thermoeconomic isolation' when applied to highly complex, highly dynamic non-linear systems. Developed at our Center for Energy Systems research, it has been effectively applied to a number of complex stationary and transportation applications.

  8. Decomposition with thermoeconomic isolation applied to the optimal synthesis/design and operation of an advanced tactical aircraft system

    International Nuclear Information System (INIS)

    A decomposition methodology based on the concept of 'thermoeconomic isolation' and applied to the synthesis/design and operational optimization of an advanced tactical fighter aircraft is the focus of this paper. The total system is composed of six sub-systems of which five participate with degrees of freedom (493) in the optimization. They are the propulsion sub-system (PS), the environmental control sub-system (ECS), the fuel loop subsystem (FLS), the vapor compression and Polyalphaolefin (PAO) loops sub-system (VC/PAOS), and the airframe sub-system (AFS). The sixth subsystem comprises the expendable and permanent payloads as well as the equipment group. For each of the first five, detailed thermodynamic, geometric, physical, and aerodynamic models at both design and off-design were formulated and implemented. The most promising set of aircraft sub-system and system configurations were then determined based on both an energy integration and aerodynamic performance analysis at each stage of the mission (including the transient ones). Conceptual, time, and physical decomposition were subsequently applied to the synthesis/design and operational optimization of these aircraft configurations as well as to the highly dynamic process of heat generation and dissipation internal to the subsystems. The physical decomposition strategy used (i.e. Iterative Local-Global Optimization-ILGO) is the first to successfully closely approach the theoretical condition of 'thermoeconomic isolation' when applied to highly complex, highly dynamic non-linear systems. Developed at our Center for Energy Systems research, it has been effectively applied to a number of complex stationary and transportation applications

  9. Effective L/D: A Theoretical Approach to the Measurement of Aero-Structural Efficiency in Aircraft Design

    Science.gov (United States)

    Guynn, Mark D.

    2015-01-01

    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.

  10. Realization of Computer-Aided Aircraft Tolerance Design%计算机辅助飞机公差优化设计的实现

    Institute of Scientific and Technical Information of China (English)

    郭长虹; 战再吉; 王振玉

    2012-01-01

    In order to solve the problem of aircraft tolerances computerization, the modeling techniques of aircraft tolerance were researched. Using UG ( UniGraphics) second development technology and VC + + , computer-aided aircraft tolerance optimization design modules were developed in the UG platform to realize computer-aided aircraft tolerance analysis and tolerance distribution. A practical and reliable aircraft tolerance database was created to realize aircraft tolerance automatic inquiry. Finally, the applied examples of aircraft tolerance analysis and tolerance distribution were given. The examples verify the correctness of the research results to complete the preliminary computerization of aircraft tolerance design and provide a technical reference for digital design of aircraft tolerances.%为了解决飞机公差设计计算机化的问题,探讨了飞机公差模型的建模技术;在UG(UniGraphics)平台上采用UG的二次开发技术和vc++,开发了计算机辅助飞机公差优化设计模块,实现了飞机公差的计算机辅助分析和分配功能;建立了实用、可靠的飞机公差数据库,实现了飞机公差的计算机自动查询功能,通过飞机公差分析和公差分配的具体设计实例,验证了研究成果的正确性,初步实现了飞机公差设计的计算机化,为飞机公差设计的数字化提供了技术参考.

  11. Study on Design of High Efficiency and Light Weight Composite Propeller Blade for a Regional Turboprop Aircraft

    Science.gov (United States)

    Kong, Changduk; Lee, Kyungsun

    2013-03-01

    In this study, aerodynamic and structural design of the composite propeller blade for a regional turboprop aircraft is performed. The thin and wide chord propeller blade of high speed turboprop aircraft should have proper strength and stiffness to carry various kinds of loads such as high aerodynamic bending and twisting moments and centrifugal forces. Therefore the skin-spar-foam sandwich structure using high strength and stiffness carbon/epoxy composite materials is used to improve the lightness. A specific design procedure is proposed in this work as follows; firstly the aerodynamic configuration design, which is acceptable for the design requirements, is carried out using the in-house code developed by authors, secondly the structure design loads are determined through the aerodynamic load case analysis, thirdly the spar flange and the skin are preliminarily sized by consideration of major bending moments and shear forces using both the netting rule and the rule of mixture, and finally, the stress analysis is performed to confirm the structural safety and stability using finite element analysis commercial code, MSC. NASTRAN/PATRAN. Furthermore the additional analysis is performed to confirm the structural safety due to bird strike impact on the blade during flight operation using a commercial code, ANSYS. To realize the proposed propeller design, the prototype blades are manufactured by the following procedure; the carbon/epoxy composite fabric prepregs are laid up for skin and spar on a mold using the hand lay-up method and consolidated with a proper temperature and vacuum in the oven. To finalize the structural design, the full-scale static structural test is performed under the simulated aerodynamic loads using 3 point loading method. From the experimental results, it is found that the designed blade has a good structural integrity, and the measured results agree well with the analytical results as well.

  12. Flutter prediction, suppression and control in aircraft composite wings as a design prerequisite: a survey

    OpenAIRE

    Njuguna, James A. K.

    2007-01-01

    Emergence of flutter compromises not only the long-term durability of the wing structure, but also the operational safety, flight performance and energy efficiency of the aircraft. Effectual means of flutter prevention are, therefore, mandatory in the certification of new flight vehicles. This work intends to address the flutter phenomenon highlighting the above issues, and reviews some of the most recent theoretical and experimental developments in flutter analyses. In the ...

  13. Reaction-time relationship and structural design of reinforced concrete slabs and shells for aircraft impact

    International Nuclear Information System (INIS)

    The reaction-time relationship for a deformable aircraft impacting on a rigid wall is derived. The resulting expression is compared to the expression presently in the literature and it is found that this new expression gives peak values of the reaction significantly less (approximately 40%) than the presently used expression The reaction-time relationships for aircraft typical of a business jet, fighter-bomber and jet transport are evaluated. The peak value of the reaction-time relationship is very sensitive to changes in the initial impact velocity and the peak value of the weight distribution and relatively insensitive to changes in the crushing strength distribution and modifications of the weight distribution that do not change the peak value of the weight distribution. A structure is required to prevent penetration by any part of the aircraft. Severe damage is to be expected. The structure will be considered to have retained its structural integrity, if it does not collapse. It is assumed that only a region of the slab or shell in the near vicinity of the region of impact participates in energy absorption. For slabs, the maximum resistance is given as the collapse load for a concentrated load. For shells with large dimensions, the same value is used as a conservative estimate. The dynamic effect are estimated using the method of Biggs. The ratio of the peak allowable force to the maximum resistance (F/R) is greater than unity as long as the participating material has a radius equal to or greater than that of the fuselage of the impacting aircraft. For any particular radius of participating material, the increase in (F/R) as a function of allowable ductility ratio is also shown. The punching shear capacity is determined by taking account of the reinforcement steel and yield line pattern

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

    OpenAIRE

    Umar Asif

    2012-01-01

    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 larg...

  15. Geometry Control System for Exploratory Shape Optimization Applied to High-Fidelity Aerodynamic Design of Unconventional Aircraft

    Science.gov (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

  16. Design of a powered elevator control system. [powered elevator system for modified C-8A aircraft for STOL operation

    Science.gov (United States)

    Glende, W. L. B.

    1974-01-01

    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.

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

    Science.gov (United States)

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

    1990-01-01

    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.

  18. Testing and Analysis of a Composite Non-Cylindrical Aircraft Fuselage Structure. Part 1; Ultimate Design Loads

    Science.gov (United States)

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

    2016-01-01

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Keidel, B.

    2000-05-18

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

  20. Preliminary Axial Flow Turbine Design and Off-Design Performance Analysis Methods for Rotary Wing Aircraft Engines. Part 2; Applications

    Science.gov (United States)

    Chen, Shu-cheng, S.

    2009-01-01

    In this paper, preliminary studies on two turbine engine applications relevant to the tilt-rotor rotary wing aircraft are performed. The first case-study is the application of variable pitch turbine for the turbine performance improvement when operating at a substantially lower shaft speed. The calculations are made on the 75 percent speed and the 50 percent speed of operations. Our results indicate that with the use of the variable pitch turbines, a nominal (3 percent (probable) to 5 percent (hypothetical)) efficiency improvement at the 75 percent speed, and a notable (6 percent (probable) to 12 percent (hypothetical)) efficiency improvement at the 50 percent speed, without sacrificing the turbine power productions, are achievable if the technical difficulty of turning the turbine vanes and blades can be circumvented. The second casestudy is the contingency turbine power generation for the tilt-rotor aircraft in the One Engine Inoperative (OEI) scenario. For this study, calculations are performed on two promising methods: throttle push and steam injection. By isolating the power turbine and limiting its air mass flow rate to be no more than the air flow intake of the take-off operation, while increasing the turbine inlet total temperature (simulating the throttle push) or increasing the air-steam mixture flow rate (simulating the steam injection condition), our results show that an amount of 30 to 45 percent extra power, to the nominal take-off power, can be generated by either of the two methods. The methods of approach, the results, and discussions of these studies are presented in this paper.

  1. 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

    2012-08-01

    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.

  2. Auralization of novel aircraft configurations

    OpenAIRE

    Arntzen, M.; Bertsch, E.L.; Simons, D.G.

    2015-01-01

    A joint initiative of NLR, DLR, and TU Delft has been initiated to streamline the process of generating audible impressions of novel aircraft configurations. The integrated approach adds to the value of the individual tools and allows predicting the sound of future aircraft before they actually fly. Hence, an existing process for the aircraft design and system noise prediction at DLR has been upgraded to generate the required input data for an aircraft auralization framework developed by NLR ...

  3. Adaptive Flight Control Design with Optimal Control Modification on an F-18 Aircraft Model

    Science.gov (United States)

    Burken, John J.; Nguyen, Nhan T.; Griffin, Brian J.

    2010-01-01

    In the presence of large uncertainties, a control system needs to be able to adapt rapidly to regain performance. Fast adaptation is referred to as the implementation of adaptive control with a large adaptive gain to reduce the tracking error rapidly; however, a large adaptive gain can lead to high-frequency oscillations which can adversely affect the robustness of an adaptive control law. A new adaptive control modification is presented that can achieve robust adaptation with a large adaptive gain without incurring high-frequency oscillations as with the standard model-reference adaptive control. The modification is based on the minimization of the Y2 norm of the tracking error, which is formulated as an optimal control problem. The optimality condition is used to derive the modification using the gradient method. The optimal control modification results in a stable adaptation and allows a large adaptive gain to be used for better tracking while providing sufficient robustness. A damping term (v) is added in the modification to increase damping as needed. Simulations were conducted on a damaged F-18 aircraft (McDonnell Douglas, now The Boeing Company, Chicago, Illinois) with both the standard baseline dynamic inversion controller and the adaptive optimal control modification technique. The results demonstrate the effectiveness of the proposed modification in tracking a reference model.

  4. Finite Difference Time Marching in the Frequency Domain: A Parabolic Formulation for Aircraft Acoustic Nacelle Design

    Science.gov (United States)

    Baumeister, Kenneth J.; Kreider, Kevin L.

    1996-01-01

    An explicit finite difference iteration scheme is developed to study harmonic sound propagation in aircraft engine nacelles. To reduce storage requirements for large 3D problems, the time dependent potential form of the acoustic wave equation is used. To insure that the finite difference scheme is both explicit and stable, time is introduced into the Fourier transformed (steady-state) acoustic potential field as a parameter. Under a suitable transformation, the time dependent governing equation in frequency space is simplified to yield a parabolic partial differential equation, which is then marched through time to attain the steady-state solution. The input to the system is the amplitude of an incident harmonic sound source entering a quiescent duct at the input boundary, with standard impedance boundary conditions on the duct walls and duct exit. The introduction of the time parameter eliminates the large matrix storage requirements normally associated with frequency domain solutions, and time marching attains the steady-state quickly enough to make the method favorable when compared to frequency domain methods. For validation, this transient-frequency domain method is applied to sound propagation in a 2D hard wall duct with plug flow.

  5. Control Design Strategies to Enhance Long-Term Aircraft Structural Integrity

    Science.gov (United States)

    Newman, Brett A.

    1999-01-01

    Over the operational lifetime of both military and civil aircraft, structural components are exposed to hundreds of thousands of low-stress repetitive load cycles and less frequent but higher-stress transient loads originating from maneuvering flight and atmospheric gusts. Micro-material imperfections in the structure, such as cracks and debonded laminates, expand and grow in this environment, reducing the structural integrity and shortening the life of the airframe. Extreme costs associated with refurbishment of critical load-bearing structural components in a large fleet, or altogether reinventoring the fleet with newer models, indicate alternative solutions for life extension of the airframe structure are highly desirable. Increased levels of operational safety and reliability are also important factors influencing the desirability of such solutions. One area having significant potential for impacting crack growth/fatigue damage reduction and structural life extension is flight control. To modify the airframe response dynamics arising from command inputs and gust disturbances, feedback loops are routinely applied to vehicles. A dexterous flight control system architecture senses key vehicle motions and generates critical forces/moments at multiple points distributed throughout the airframe to elicit the desired motion characteristics. In principle, these same control loops can be utilized to influence the level of exposure to harmful loads during flight on structural components. Project objectives are to investigate and/or assess the leverage control has on reducing fatigue damage and enhancing long-term structural integrity, without degrading attitude control and trajectory guidance performance levels. In particular, efforts have focused on the effects inner loop control parameters and architectures have on fatigue damage rate. To complete this research, an actively controlled flexible aircraft model and a new state space modeling procedure for crack growth

  6. Preliminary weight and cost estimates for transport aircraft composite structural design concepts

    Science.gov (United States)

    1973-01-01

    Preliminary weight and cost estimates have been prepared for design concepts utilized for a transonic long range transport airframe with extensive applications of advanced composite materials. The design concepts, manufacturing approach, and anticipated details of manufacturing cost reflected in the composite airframe are substantially different from those found in conventional metal structure and offer further evidence of the advantages of advanced composite materials.

  7. Reconfigurable Control Design with Neural Network Augmentation for a Modified F-15 Aircraft

    Science.gov (United States)

    Burken, John J.

    2007-01-01

    The viewgraphs present background information about reconfiguration control design, design methods used for paper, control failure survivability results, and results and time histories of tests. Topics examined include control reconfiguration, general information about adaptive controllers, model reference adaptive control (MRAC), the utility of neural networks, radial basis functions (RBF) neural network outputs, neurons, and results of investigations of failures.

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

    NARCIS (Netherlands)

    Cooper, C.A.

    2011-01-01

    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

  9. Design-of-experiments to Reduce Life-cycle Costs in Combat Aircraft Inlets

    Science.gov (United States)

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

    2003-01-01

    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).

  10. Design of a high-performance rotary stratified-charge research aircraft engine

    Science.gov (United States)

    Jones, C.; Mount, R. E.

    1984-01-01

    The power section for an advanced rotary stratified-charge general aviation engine has been designed under contract to NASA. The single-rotor research engine of 40 cubic-inches displacement (RCI-40), now being procured for test initiation this summer, is targeted for 320 T.O. horse-power in a two-rotor production engine. The research engine is designed for operating on jet-fuel, gasoline or diesel fuel and will be used to explore applicable advanced technologies and to optimize high output performance variables. Design of major components of the engine is described in this paper.

  11. Modified Linear Theory Aircraft Design Tools and Sonic Boom Minimization Strategy Applied to Signature Freezing via F-function Lobe Balancing

    Science.gov (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

  12. A system for aerodynamic design and analysis of supersonic aircraft. Part 3: Computer program description

    Science.gov (United States)

    Middleton, W. D.; Lundry, J. L.; Coleman, R. G.

    1980-01-01

    The computer program documentation for the design and analysis of supersonic configurations is presented. Schematics and block diagrams of the major program structure, together with subroutine descriptions for each module are included.

  13. Innovative Structural and Material Concepts for Low-Weight Low-Drag Aircraft Design Project

    Data.gov (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...

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

    Data.gov (United States)

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

  15. Active Flow Control with Adaptive Design Techniques for Improved Aircraft Safety Project

    Data.gov (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...

  16. Design of an enhanced air data sensor for a very light aircraft

    OpenAIRE

    Castro Arnau, Oriol; Folch Codera, Anna

    2009-01-01

    This project is the following part of a previous thesis about the design, development and implementation of a data acquisition system: “Development of an Integrated Flight Test Instrumentation System for Ultra Light Machines” called Mnemosine by Alberto Rolando. Participating in the improvement of the part Urania. Once the new design was decided and the implementation was done, the calibration of the new Pitot – boom has become a critical part where the pressure sensors, tem...

  17. Design of an enhancep air data sensor for very light aircraft

    OpenAIRE

    Castro Arnau, Oriol

    2009-01-01

    This project is the following part of a previous thesis about the design, development and implementation of a data acquisition system: "Development of an Integrated Flight Test Instrumentation System for Ultra Light Machines" called Mnemosine by Alberto Rolando. Participating in the improvement of the part Urania. Once the new design was decided and the implementation was done, the calibration of the new Pitot - boom has become a critical part where the pressure sensors, temperature sensor an...

  18. Design of an enhanced air data sensor for a very light aircraft

    OpenAIRE

    Folch Codera, Anna

    2009-01-01

    This project is the following part of a previous thesis about the design, development and implementation of a data acquisition system: "Development of an Integrated Flight Test Instrumentation System for Ultra Light Machines" called Mnemosine by Alberto Rolando. Participating in the improvement of the part Urania. Once the new design was decided and the implementation was done, the calibration of the new Pitot - boom has become a critical part where the pressure sensors, temperature sensor an...

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

    Science.gov (United States)

    Shrivastava, Sachin; Mohite, P. M.

    2015-01-01

    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.

  20. 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

    2015-01-01

    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.

  1. Experiment Design for Complex VTOL Aircraft with Distributed Propulsion and Tilt Wing

    Science.gov (United States)

    Murphy, Patrick C.; Landman, Drew

    2015-01-01

    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.

  2. 76 FR 78096 - U.S. Advanced Boiling Water Reactor Aircraft Impact Design Certification Amendment

    Science.gov (United States)

    2011-12-16

    ... are specifically designed to ensure that the reactor can be shutdown and decay heat can be removed..., 2009 (74 FR 62829). On June 12, 2009 (74 FR 28112), the NRC amended its regulations to require... proposed rule in the Federal Register on January 20, 2011 (76 FR 3540). The public comment period for...

  3. Guidance Systems of Fighter Aircraft

    Directory of Open Access Journals (Sweden)

    K.N. Rajanikanth

    2005-07-01

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

  4. Transport and Chemical Evolution over the Pacific (TRACE-P) aircraft mission: Design, execution, and first results

    OpenAIRE

    Jacob, Daniel James; Crawford, James; Kleb, Mary; Connors, VIckie; Bendura, Richard; Raper, James; Sachse, Glen; Gille, John; Emmons, Louisa; Heald, Colette

    2003-01-01

    The NASA Transport and Chemical Evolution over the Pacific (TRACE-P) aircraft mission was conducted in February–April 2001 over the NW Pacific (1) to characterize the Asian chemical outflow and relate it quantitatively to its sources and (2) to determine its chemical evolution. It used two aircraft, a DC-8 and a P-3B, operating out of Hong Kong and Yokota Air Force Base (near Tokyo), with secondary sites in Hawaii, Wake Island, Guam, Okinawa, and Midway. The aircraft carried instrumentation f...

  5. Challenges and Progress in Aerodynamic Design of Hybrid Wingbody Aircraft with Embedded Engines

    Science.gov (United States)

    Liou, Meng-Sing; Kim, Hyoungjin; Liou, May-Fun

    2016-01-01

    We summarize the contributions to high-fidelity capabilities for analysis and design of hybrid wingbody (HWB) configurations considered by NASA. Specifically, we focus on the embedded propulsion concepts of the N2-B and N3-X configurations, some of the future concepts seriously investigated by the NASA Fixed Wing Project. The objective is to develop the capability to compute the integrated propulsion and airframe system realistically in geometry and accurately in flow physics. In particular, the propulsion system (including the entire engine core-compressor, combustor, and turbine stages) is vastly more difficult and costly to simulate with the same level of fidelity as the external aerodynamics. Hence, we develop an accurate modeling approach that retains important physical parameters relevant to aerodynamic and propulsion analyses for evaluating the HWB concepts. Having the analytical capabilities at our disposal, concerns and issues that were considered to be critical for the HWB concepts can now be assessed reliably and systematically; assumptions invoked by previous studies were found to have serious consequences in our study. During this task, we establish firmly that aerodynamic analysis of a HWB concept without including installation of the propulsion system is far from realistic and can be misleading. Challenges in delivering the often-cited advantages that belong to the HWB are the focus of our study and are emphasized in this report. We have attempted to address these challenges and have had successes, which are summarized here. Some can have broad implications, such as the concept of flow conditioning for reducing flow distortion and the modeling of fan stages. The design optimization capability developed for improving the aerodynamic characteristics of the baseline HWB configurations is general and can be employed for other applications. Further improvement of the N3-X configuration can be expected by expanding the design space. Finally, the support of

  6. Aircraft energy efficiency laminar flow control glove flight conceptual design study

    Science.gov (United States)

    Wright, A. S.

    1979-01-01

    A laminar flow control glove applied to the wing of a short to medium range jet transport with aft mounted engines was designed. A slotted aluminum glove concept and a woven stainless steel mesh porous glove concept suction surfaces were studied. The laminar flow control glove and a dummy glove with a modified supercritical airfoil, ducting, modified wing leading and trailing edges, modified flaps, and an LFC trim tab were applied to the wing after slot spacing suction parameters, and compression power were determined. The results show that a laminar flow control glove can be applied to the wing of a jet transport with an appropriate suction system installed.

  7. Design and analysis of aerospace structures at elevated temperatures. [aircraft, missiles, and space platforms

    Science.gov (United States)

    Chang, C. I.

    1989-01-01

    An account is given of approaches that have emerged as useful in the incorporation of thermal loading considerations into advanced composite materials-based aerospace structural design practices. Sources of structural heating encompass not only propulsion system heat and aerodynamic surface heating at supersonic speeds, but the growing possibility of intense thermal fluxes from directed-energy weapons. The composite materials in question range from intrinsically nonheat-resistant polymer matrix systems to metal-matrix composites, and increasingly to such ceramic-matrix composites as carbon/carbon, which are explicitly intended for elevated temperature operation.

  8. Design of the RC containment shell of a nuclear reactor for aircraft impact

    International Nuclear Information System (INIS)

    This paper deals with the following points: i) Characterization of a particular region of the shell which is modeled as a one-degree-of freedom system for the non-linear dynamic analysis. This is achieved through a proper interpretation of the results of the global analysis. ii) Development of a method of non-linear dynamic analysis for the considered one-degree-of freedom model. iii) Comparative analysis of the design for flexural strength, and punching shear, according to American and German standards. Interaction diagrams for bending and normal force are developed according to the two standards. The concepts of the foregoing items are exemplified with the verification of the shell reinforcement of a PWR reactor. A simplified method of non-linear dynamic analysis for airplane crash is presented. This method takes into account all the important influences of the problem. The results of this analysis are used in the design of the shell reinforcement according to American and German Standards. (orig./HP)

  9. Designing Serious Games for Safety Education: "Learn to Brace" versus Traditional Pictorials for Aircraft Passengers.

    Science.gov (United States)

    Chittaro, Luca

    2016-05-01

    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. PMID:27045909

  10. Advanced composite rudders for DC-10 aircraft: Design, manufacturing, and ground tests

    Science.gov (United States)

    Lehman, G. M.; Purdy, D. M.; Cominsky, A.; Hawley, A. V.; Amason, M. P.; Kung, J. T.; Palmer, R. J.; Purves, N. B.; Marra, P. J.; Hancock, G. R.

    1976-01-01

    Design synthesis, tooling and process development, manufacturing, and ground testing of a graphite epoxy rudder for the DC-10 commercial transport are discussed. The composite structure was fabricated using a unique processing method in which the thermal expansion characteristics of rubber tooling mandrels were used to generate curing pressures during an oven cure cycle. The ground test program resulted in certification of the rudder for passenger-carrying flights. Results of the structural and environmental tests are interpreted and detailed development of the rubber tooling and manufacturing process is described. Processing, tooling, and manufacturing problems encountered during fabrication of four development rudders and ten flight-service rudders are discussed and the results of corrective actions are described. Non-recurring and recurring manufacturing labor man-hours are tabulated at the detailed operation level. A weight reduction of 13.58 kg (33 percent) was attained in the composite rudder.

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

    Data.gov (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...

  12. Amphibious Aircraft

    Data.gov (United States)

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

  13. Automated Generation of Finite-Element Meshes for Aircraft Conceptual Design

    Science.gov (United States)

    Li, Wu; Robinson, Jay

    2016-01-01

    This paper presents a novel approach for automated generation of fully connected finite-element meshes for all internal structural components and skins of a given wing-body geometry model, controlled by a few conceptual-level structural layout parameters. Internal structural components include spars, ribs, frames, and bulkheads. Structural layout parameters include spar/rib locations in wing chordwise/spanwise direction and frame/bulkhead locations in longitudinal direction. A simple shell thickness optimization problem with two load conditions is used to verify versatility and robustness of the automated meshing process. The automation process is implemented in ModelCenter starting from an OpenVSP geometry and ending with a NASTRAN 200 solution. One subsonic configuration and one supersonic configuration are used for numerical verification. Two different structural layouts are constructed for each configuration and five finite-element meshes of different sizes are generated for each layout. The paper includes various comparisons of solutions of 20 thickness optimization problems, as well as discussions on how the optimal solutions are affected by the stress constraint bound and the initial guess of design variables.

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

    Directory of Open Access Journals (Sweden)

    Erwin V. Zaretsky

    2003-01-01

    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.

  15. Design Optimization and Verification of a Horizontal Stabilizer for the SeaStryder600 Wing-In-Ground-Effect (WIG) Aircraft

    Science.gov (United States)

    Haley, Stephen

    Aircraft manufacturer Aquavion Systems is currently designing and constructing prototypes for its revolutionary new fleet of aircraft called the SeaStryder. During the prototyping phase, it was discovered that the center-of-gravity of the SeaStryder600 was too far aft and outside of the acceptable range. To solve this design issue, it was hypothesized that the weight of the horizontal stabilizer may be reduced without compromising its structural integrity. The following document analyzes this hypothesis and provides two alternative designs. Each design exceeds the design requirements, meets additional requirements requested by industry, and provides a significant degree of weight savings. The first design provides a 25% weight reduction. The second design provides an 18% weight reduction as well as a 160% increase in loading capacity. The designs proposed have both been verified through the use of Finite Element Analysis as well as by means of experimentation where two prototype wings were constructed and tested to failure confirming the analytical results.

  16. Aircraft electromagnetic compatibility

    Science.gov (United States)

    Clarke, Clifton A.; Larsen, William E.

    1987-01-01

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

  17. Aircraft Noise

    Science.gov (United States)

    Michel, Ulf; Dobrzynski, Werner; Splettstoesser, Wolf; Delfs, Jan; Isermann, Ullrich; Obermeier, Frank

    Aircraft industry is exposed to increasing public pressure aiming at a continuing reduction of aircraft noise levels. This is necessary to both compensate for the detrimental effect on noise of the expected increase in air traffic and improve the quality of living in residential areas around airports.

  18. Aircraft Data Acquisition

    Directory of Open Access Journals (Sweden)

    Elena BALMUS

    2016-03-01

    Full Text Available 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 of this division in aviation, data optimization and comparison has been quite an important task. The interest in using data acquisition boards is being driven by the technology and design standards in the new generation of aircraft and the ongoing efforts of reducing weight and, in some cases addressing the safety risks. This paper presents a sum of technical report data from post processing and diversification of data acquisition from Arinc 429 interface on a research aircraft platform. Arinc 429 is by far the most common data bus in use on civil transport aircraft, regional jets and executive business jets today. Since its introduction on the Boeing 757/767 and Airbus aircraft in the early 1980s hardly any aircraft has been produced without the use of this data bus. It was used widely by the air transport indu

  19. Fiber optic hardware for transport aircraft

    Science.gov (United States)

    White, John A.

    1994-10-01

    Aircraft manufacturers are developing fiber optic technology to exploit the benefits in system performance and manufacturing cost reduction. The fiber optic systems have high bandwidths and exceptional Electromagnetic Interference immunity that exceeds all new aircraft design requirements. Additionally, aircraft manufacturers have shown production readiness of fiber optic systems and design feasibility.

  20. Design and commission of an experimental test rig to apply a full-scale pressure load on composite sandwich panels representative of an aircraft secondary structure

    International Nuclear Information System (INIS)

    This paper describes the design of a test rig, which is used to apply a representative pressure load to a full-scale composite sandwich secondary aircraft structure. A generic panel was designed with features to represent those in the composite sandwich secondary aircraft structure. To provide full-field strain data from the panels, the test rig was designed for use with optical measurement techniques such as thermoelastic stress analysis (TSA) and digital image correlation (DIC). TSA requires a cyclic load to be applied to a structure for the measurement of the strain state; therefore, the test rig has been designed to be mounted on a standard servo-hydraulic test machine. As both TSA and DIC require an uninterrupted view of the surface of the test panel, an important consideration in the design is facilitating the optical access for the two techniques. To aid the test rig design a finite element (FE) model was produced. The model provides information on the deflections that must be accommodated by the test rig, and ensures that the stress and strain levels developed in the panel when loaded in the test rig would be sufficient for measurement using TSA and DIC. Finally, initial tests using the test rig have shown it to be capable of achieving the required pressure and maintaining a cyclic load. It was also demonstrated that both TSA and DIC data can be collected from the panels under load, which are used to validate the stress and deflection derived from the FE model

  1. Conceptual design, evaluation and research identification for Remote Augmented Propulsive Lift Systems (RALS) with ejectors for VTOL aircraft

    Science.gov (United States)

    Willis, W. S.; Konarski, M.; Sutherland, M. V.

    1982-01-01

    Ejector concepts for use with a remote augmented lift system (RALS) exhaust nozzle were studied. A number of concepts were considered and three were selected as having the greatest promise of providing the desired aircraft and exhaust gas cooling and lift enhancement. A scale model test program is recommended to explore the effects of the more important parameters on ejector performance.

  2. Aircraft Carriers

    DEFF Research Database (Denmark)

    Nødskov, Kim; Kværnø, Ole

    the majority of its foreign trade, as well as its oil imports, upon which the country is totally dependent. China therefore has good reasons for acquiring an aircraft carrier to enable it to protect its national interests. An aircraft carrier would also be a prominent symbol of China’s future status...... information is pieced together, then a picture is created of a Chinese aircraft carrier program, where Varyag will be made operational for training purposes. With this as the model, China will build a similar sized carrier themselves. If this project does become a reality, then it will take many years for...... Kuznetsov carrier. The SU-33 is, in its modernized version, technologically at the same level as western combat aircraft in both the offensive as well as the defensive roles. But Russia and China currently have an arms trade 6 dispute that is likely to prevent a deal, unless the dispute is resolved. As an...

  3. 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

    2013-02-01

    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

  4. 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

    2012-01-01

    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.

  5. Structural integrity in aircraft.

    Science.gov (United States)

    Hardrath, H. F.

    1973-01-01

    The paper reviews briefly the current design philosophies for achieving long, efficient, and reliable service in aircraft structures. The strengths and weaknesses of these design philosophies and their demonstrated records of success are discussed. The state of the art has not been developed to the point where designing can be done without major test inspection and maintenance programs. A broad program of research is proposed through which a viable computerized design scheme will be provided during the next decade. The program will organize and correlate existing knowledge on fatigue and fracture behavior, identify gaps in this knowledge, and guide specific research to upgrade design capabilities.

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

    Science.gov (United States)

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

    1992-01-01

    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.

  7. The Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) mission: design, execution, and first results

    Science.gov (United States)

    Jacob, D. J.; Crawford, J. H.; Maring, H.; Clarke, A. D.; Dibb, J. E.; Emmons, L. K.; Ferrare, R. A.; Hostetler, C. A.; Russell, P. B.; Singh, H. B.; Thompson, A. M.; Shaw, G. E.; McCauley, E.; Pederson, J. R.; Fisher, J. A.

    2010-06-01

    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). Its goal was to better understand the factors driving current changes in Arctic atmospheric composition and climate, including (1) influx of mid-latitude pollution, (2) boreal forest fires, (3) aerosol radiative forcing, and (4) chemical processes. The June-July deployment was preceded by one week of flights over California (ARCTAS-CARB) focused on (1) improving state emission inventories for greenhouse gases and aerosols, (2) providing observations to test and improve models of ozone and aerosol pollution. ARCTAS involved three aircraft: a DC-8 with a detailed chemical payload, a P-3 with an extensive aerosol and radiometric payload, and a B-200 with aerosol remote sensing instrumentation. The aircraft data augmented satellite observations of Arctic atmospheric composition, in particular from the NASA A-Train. The spring phase (ARCTAS-A) revealed pervasive Asian pollution throughout the Arctic as well as significant European pollution below 2 km. Unusually large Siberian fires in April 2008 caused high concentrations of carbonaceous aerosols and also affected ozone. Satellite observations of BrO column hotspots were found not to be related to Arctic boundary layer events but instead to tropopause depressions, suggesting the presence of elevated inorganic bromine (5-10 pptv) in the lower stratosphere. Fresh fire plumes from Canada and California sampled during the summer phase (ARCTAS-B) indicated low NOx emission factors from the fires, rapid conversion of NOx to PAN, no significant secondary aerosol production, and no significant ozone enhancements except when mixed with urban pollution.

  8. The Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS mission: design, execution, and first results

    Directory of Open Access Journals (Sweden)

    D. J. Jacob

    2010-06-01

    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. Its goal was to better understand the factors driving current changes in Arctic atmospheric composition and climate, including (1 influx of mid-latitude pollution, (2 boreal forest fires, (3 aerosol radiative forcing, and (4 chemical processes. The June–July deployment was preceded by one week of flights over California (ARCTAS-CARB focused on (1 improving state emission inventories for greenhouse gases and aerosols, (2 providing observations to test and improve models of ozone and aerosol pollution. ARCTAS involved three aircraft: a DC-8 with a detailed chemical payload, a P-3 with an extensive aerosol and radiometric payload, and a B-200 with aerosol remote sensing instrumentation. The aircraft data augmented satellite observations of Arctic atmospheric composition, in particular from the NASA A-Train. The spring phase (ARCTAS-A revealed pervasive Asian pollution throughout the Arctic as well as significant European pollution below 2 km. Unusually large Siberian fires in April 2008 caused high concentrations of carbonaceous aerosols and also affected ozone. Satellite observations of BrO column hotspots were found not to be related to Arctic boundary layer events but instead to tropopause depressions, suggesting the presence of elevated inorganic bromine (5–10 pptv in the lower stratosphere. Fresh fire plumes from Canada and California sampled during the summer phase (ARCTAS-B indicated low NOx emission factors from the fires, rapid conversion of NOx to PAN, no significant secondary aerosol production, and no significant ozone enhancements except when mixed with urban pollution.

  9. 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)

    王子熙

    2014-01-01

    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。

  10. Transport and Chemical Evolution over the Pacific (TRACE-P)Aircraft Mission: Design, Execution, and First Results

    Science.gov (United States)

    Jacob, Daniel J.; Crawford, James H.; Kleb, Mary M.; Connors, Vickie S.; Bendura, Richard J.; Raper, James L.; Sachse, Glen W.; Gille, John C.; Emmons, Louisa; Heald, Colette L.

    2003-01-01

    The NASA Transport and Chemical Evolution over the Pacific (TRACE-P) aircraft mission was conducted in February-April 2001 over the NW Pacific (1) to characterize the Asian chemical outflow and relate it quantitatively to its sources and (2) to determine its chemical evolution. It used two aircraft, a DC-8 and a P-3B, operating out of Hong Kong and Yokota Air Force Base (near Tokyo), with secondary sites in Hawaii, Wake Island, Guam, Okinawa, and Midway. The aircraft carried instrumentation for measurements of long-lived greenhouse gases, ozone and its precursors, aerosols and their precursors, related species, and chemical tracers. Five chemical transport models (CTMs) were used for chemical forecasting. Customized bottom-up emission inventories for East Asia were generated prior to the mission to support chemical forecasting and to serve as a priori for evaluation with the aircraft data. Validation flights were conducted for the Measurements Of Pollution In The Troposphere (MOPITT) satellite instrument and revealed little bias (6 plus or minus 2%) in the MOPITT measurements of CO columns. A major event of transpacific Asian pollution was characterized through combined analysis of TRACE-P and MOPITT data. The TRACE-P observations showed that cold fronts sweeping across East Asia and the associated warm conveyor belts (WCBs) are the dominant pathway for Asian outflow to the Pacific in spring. The WCBs lift both anthropogenic and biomass burning (SE Asia) effluents to the free troposphere, resulting in complex chemical signatures. The TRACE-P data are in general consistent with a priori emission inventories, lending confidence in our ability to quantify Asian emissions from socioeconomic data and emission factors. However, the residential combustion source in rural China was found to be much larger than the a priori, and there were also unexplained chemical enhancements (HCN, CH3Cl, OCS, alkylnitrates) in Chinese urban plumes. The Asian source of CCl4 was found to

  11. Aircraft cybernetics

    Science.gov (United States)

    1977-01-01

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

  12. Aircraft Wiring Support Equipment Integration Laboratory (AWSEIL)

    Data.gov (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...

  13. 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

    2013-07-01

    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

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

    Science.gov (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.

    2013-01-01

    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.

  15. Effect of creep in titanium alloy Ti-6Al-4V at elevated temperature on aircraft design and flight test

    Science.gov (United States)

    Jenkins, J. M.

    1984-01-01

    Short-term compressive creep tests were conducted on three titanium alloy Ti-6Al-4V coupons at three different stress levels at a temperature of 714 K (825 F). The test data were compared to several creep laws developed from tensile creep tests of available literature. The short-term creep test data did not correlate well with any of the creep laws obtained from available literature. The creep laws themselves did not correlate well with each other. Short-term creep does not appear to be very predictable for titanium alloy Ti-6Al-4V. Aircraft events that result in extreme, but short-term temperature and stress excursions for this alloy should be approached cautiously. Extrapolations of test data and creep laws suggest a convergence toward predictability in the longer-term situation.

  16. Algorithm project weight calculation aircraft

    Directory of Open Access Journals (Sweden)

    Г. В. Абрамова

    2013-07-01

    Full Text Available The paper describes the process of a complex technical object design on the example of the aircraft, using information technology such as CAD/CAM/CAE-systems, presents the basic models of aircraft which are developed in the process of designing and reflect the different aspects of its structure and function. The idea of control parametric model at complex technical object design is entered, which is a set of initial data for the development of design stations and enables the optimal complex technical object control at all stages of design using modern computer technology. The paper discloses a process of weight design, which is associated with all stages of development aircraft and its production. Usage of a scheduling algorithm that allows to organize weight calculations are carried out at various stages of planning and weighing options to optimize the use of available database of formulas and methods of calculation

  17. An investigation of the accuracy of empirical aircraft design for the development of an unmanned aerial vehicle intended for liquid hydrogen fuel

    Science.gov (United States)

    Chaney, Christopher Scott

    A study was conducted to assess the accuracy of empirical techniques used for the calculation of flight performance for unmanned aerial vehicles. This was achieved by quantifying the error between a mathematical model developed with these techniques and experimental test data taken using an unmanned aircraft. The vehicle utilized for this study was developed at Washington State University for the purpose of flying using power derived from hydrogen stored as a cryogenic liquid. The vehicle has a mass of 32.8 kg loaded and performed a total of 14 flights under battery power for 3.58 total flight hours. Over these flights, the design proved it is capable of sustaining level flight from the power available from a PEM fuel cell propulsion system. The empirical techniques used by the model are explicitly outlined within. These yield several performance metrics that are compared to measurements taken during flight testing. Calculations of required thrust for steady flight over all airspeeds and rates of climb modeled are found to have a mean percent error of 3.2%+/-7.0% and a mean absolute percent error of 34.6%+/-5.1%. Comparison of the calculated and measured takeoff distance are made and the calculated thrust required to perform a level turn at a given rate is compared to flight test data. A section of a test flight is analyzed, over which the vehicle proves it can sustain level flight under 875 watts of electrical power. The aircraft's design is presented including the wing and tail, propulsion system, and build technique. The software and equipment used for the collection and analysis of flight data are given. Documentation and validation is provided of a unique test rig for the characterization of propeller performance using a car. The aircraft remains operational to assist with research of alternative energy propulsion systems and novel fuel storage techniques. The results from the comparison of the mathematical model and flight test data can be utilized to assist

  18. Sensitivity of Mission Energy Consumption to Turboelectric Distributed Propulsion Design Assumptions on the N3-X Hybrid Wing Body Aircraft

    Science.gov (United States)

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

    2012-01-01

    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

  19. A NASA study of the impact of technology on future multimission aircraft

    Science.gov (United States)

    Samuels, Jeffrey J.

    1992-01-01

    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.

  20. APPLICATION FOR AIRCRAFT TRACKING

    OpenAIRE

    Ostroumov, Ivan; Kuz’menko, Natalia

    2011-01-01

    Abstract. In the article the important problems of software development for aircraft tracking have beendiscussed. Position reports of ACARS have been used for aircraft tracking around the world.An algorithm of aircraft coordinates decoding and visualization of aircraft position on the map has beenrepresented.Keywords: ACARS, aircraft, internet, position, software, tracking.

  1. Genetic algorithms in conceptual design of a light-weight, low-noise, tilt-rotor aircraft

    Science.gov (United States)

    Wells, Valana L.

    1996-01-01

    This report outlines research accomplishments in the area of using genetic algorithms (GA) for the design and optimization of rotorcraft. It discusses the genetic algorithm as a search and optimization tool, outlines a procedure for using the GA in the conceptual design of helicopters, and applies the GA method to the acoustic design of rotors.

  2. Actuation technology for flight control system on civil aircraft

    OpenAIRE

    Xue, L.

    2009-01-01

    This report addresses the author’s Group Design Project (GDP) and Individual Research Project (IRP). The IRP is discussed primarily herein, presenting the actuation technology for the Flight Control System (FCS) on civil aircraft. Actuation technology is one of the key technologies for next generation More Electric Aircraft (MEA) and All Electric Aircraft (AEA); it is also an important input for the preliminary design of the Flying Crane, the aircraft designed in the author’s G...

  3. Fault Tolerance, Diagnostics, and Prognostics in Aircraft Flight

    Data.gov (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...

  4. Euler Technology Assessment for Preliminary Aircraft Design-Unstructured/Structured Grid NASTD Application for Aerodynamic Analysis of an Advanced Fighter/Tailless Configuration

    Science.gov (United States)

    Michal, Todd R.

    1998-01-01

    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.

  5. Advanced manufacturing development of a composite empennage component for L-1011 aircraft. Phase 2: Design and analysis

    Science.gov (United States)

    Jackson, A. C.; Crocker, J. F.; Ekvall, J. C.; Eudaily, R. R.; Mosesian, B.; Vancleave, R. R.; Vanhamersveld, J.

    1981-01-01

    The composite fin design consists of two one-piece cocured covers, two one-piece cocured spars and eleven ribs. The lower ribs are truss ribs with graphite/epoxy caps and aluminum truss members. The upper three ribs are a sandwich design with graphite/epoxy face sheets and a syntactic epoxy core. The design achieves a 27% weight saving compared to the metal box. The fastener count has been reduced from over 40,000 to less than 7000. The structural integrity of the composite fin was verified by analysis and test. The static, fail-safe and flutter analyses were completed. An extensive test program has established the material behavior under a range of conditions and critical subcomponents were tested to verify the structural concepts.

  6. Advanced technology for future regional transport aircraft

    Science.gov (United States)

    Williams, L. J.

    1982-01-01

    In connection with a request for a report coming from a U.S. Senate committee, NASA formed a Small Transport Aircraft Technology (STAT) team in 1978. STAT was to obtain information concerning the technical improvements in commuter aircraft that would likely increase their public acceptance. Another area of study was related to questions regarding the help which could be provided by NASA's aeronautical research and development program to commuter aircraft manufacturers with respect to the solution of technical problems. Attention is given to commuter airline growth, current commuter/region aircraft and new aircraft in development, prospects for advanced technology commuter/regional transports, and potential benefits of advanced technology. A list is provided of a number of particular advances appropriate to small transport aircraft, taking into account small gas turbine engine component technology, propeller technology, three-dimensional wing-design technology, airframe aerodynamics/propulsion integration, and composite structure materials.

  7. Laminar flow control for transport aircraft applications

    Science.gov (United States)

    Wagner, R. D.

    1986-01-01

    The incorporation of laminar flow control into transport aircraft is discussed. Design concepts for the wing surface panel of laminar flow control transport aircraft are described. The development of small amounts of laminar flow on small commercial transports with natural or hybrid flow control is examined. Techniques for eliminating the insect contamination problem in the leading-edge region are proposed.

  8. Noise control mechanisms of inside aircraft

    Science.gov (United States)

    Zverev, A. Ya.

    2016-07-01

    World trends in the development of methods and approaches to noise reduction in aircraft cabins are reviewed. The paper discusses the mechanisms of passive and active noise and vibration control, application of "smart" and innovative materials, new approaches to creating all fuselage-design elements, and other promising directions of noise control inside aircraft.

  9. 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

    2005-01-01

    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.

  10. Design, testing and demonstration of a small unmanned aircraft system (sUAS) and payload for measuring wind speed and particulate matter in the atmospheric boundary layer

    Science.gov (United States)

    Riddell, Kevin Donald Alexander

    The atmospheric boundary layer (ABL) is the layer of air directly influenced by the Earth's surface and is the layer of the atmosphere most important to humans as this is the air we live in. Methods for measuring the properties of the ABL include three general approaches: satellite based, ground based and airborne. A major research challenge is that many contemporary methods provide a restricted spatial resolution or coverage of variations of ABL properties such as how wind speed varies across a landscape with complex topography. To enhance our capacity to measure the properties of the ABL, this thesis presents a new technique that involves a small unmanned aircraft system (sUAS) equipped with a customized payload for measuring wind speed and particulate matter. The research presented herein outlines two key phases in establishing the proof of concept of the payload and its integration on the sUAS: (1) design and testing and (2) field demonstration. The first project focuses on measuring wind speed, which has been measured with fixed wing sUASs in previous research. but not with a helicopter sUAS. The second project focuses on the measurement of particulate matter, which is a major air pollutant typically measured with ground-based sensors. Results from both proof of concept projects suggest that ABL research could benefit from the proposed techniques. .

  11. Design characteristics to reduce inadvertent cross-axis coupling during side stick handling of aircraft pitch and roll axis control

    Science.gov (United States)

    Cote, Marie-Eve

    Integrating a manual flight control inceptor with coupled axes such as the side stick within a flight deck creates challenges for the pilot to input a one-axis command without inadvertently inducing inputs in the opposite axis. The present paper studies three design features of the side stick and armrest setup believed to help reduce inadvertent cross-axis coupling occurrences. Design features address the aimed pilot population anthropometry (1.57m woman to 1.9m male) and their variability in upper segment measurements. Seven pilots of varying anthropometric sizes were asked to perform one-axis manoeuvres in pitch and roll for each setup configuration. To compare the setups both the duration and the definite integral of the unintended cross-axis input were processed and analyzed for each manoeuvre. Findings show that a short armrest reduces the occurrences of cross-axis input for the roll manoeuvre, whereas the side stick skew reduces inadvertent cross-axis coupling for the pitch manoeuvres.

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

    Science.gov (United States)

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

    1991-01-01

    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.

  13. 适应未来大型飞机的水泥混凝土道面设计方法%Airport concrete pavement design for large aircraft in future

    Institute of Scientific and Technical Information of China (English)

    吴爱红; 蔡良才; 顾强康; 李光元

    2011-01-01

    The present concrete pavement design specification uses design aircraft to convert the traffic of other aircrafts into traffic of design aircraft according to the principle of equivalent damage, and it assumes that the wheel path in the lane of runway follows uniform distribution. Actually, wheel path follows the normal school, landing gear of new large aircraft becomes more complex, the peak value of cumulative damage of each aircraft maybe not at the same location, shortages of conversion method using design aircraft is increasing. Based on the wheel path in the lane of runway follows the normal school, pass-to-coverage ratio is used to calculate passes number. Design aircraft's function is replaced by cumulative fatigue damage of pavement structure, which produced by all kinds of aircrafts is carried out directly. A new design method for concrete pavement based on cumulative fatigue damage is discussed and a design example is given. It is approved that the pavement design method using cumulative fatigue damage as design index is more suitable for concrete pavement design of large aircraft with complex landing gear.%现行水泥混凝土道面设计规范,采用“设计飞机”按疲劳等效原则将各型飞机的作用次数换算成“设计飞机”的作用次数,并假定飞机轮迹在通行宽度内均匀分布,实际上飞机轮迹在跑道横断面上服从正态分布.未来大型飞机的起落架更加复杂,各型飞机对道面的累积疲劳损伤峰值不在同一位置,采用“设计飞机”换算的方法日益暴露出不足.按轮迹服从正态分布采用覆盖通行率计算覆盖作用次数,用累积疲劳损伤替代了“设计飞机”在交通量换算中的作用,直接计算各型飞机对道面结构总的累积疲劳损伤,探讨了基于累积疲劳损伤的道面设计方法.实例分析表明:采用累计疲劳损伤作为设计指标的道面设计方法计算结果更精确,更适合未来

  14. Future aircraft networks and schedules

    Science.gov (United States)

    Shu, Yan

    2011-07-01

    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

  15. Adaptive Multigrid Methods for Fluid-Structure Interaction (FSI) Optimization in an Aircraft and Design of Integrated Structural Health Monitoring (SHM) Systems

    OpenAIRE

    Ebna Hai, Bhuiyan Shameem Mahmood; Bause, Markus

    2013-01-01

    Nowadays, advanced composite materials such as carbon fiber reinforced plastics (CFRP) are being applied to many aircraft structures in order to improve performance and reduce weight. Most composites have strong, stiff fibres in a matrix which is weaker and less stiff. However, aircraft wings can break due to Fluid-Structure Interaction (FSI) oscillations or material fatigue. Material inspection by piezoelectric induced ultrasonic waves is a relatively new and an intelligent technique to moni...

  16. Scorpion: Close Air Support (CAS) aircraft

    Science.gov (United States)

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

    1991-01-01

    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.

  17. Impact of Advanced Propeller Technology on Aircraft/Mission Characteristics of Several General Aviation Aircraft

    Science.gov (United States)

    Keiter, I. D.

    1982-01-01

    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.

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

    Science.gov (United States)

    Ram Prabhu, T.

    2016-04-01

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

  19. 概念设计阶段起落架接地点设计%The Landing Gear Touchdown Point Design of Advanced Civil Jet Aircraft in Concept Design Phase

    Institute of Scientific and Technical Information of China (English)

    王跃

    2012-01-01

    针对现代民用飞机设计特点,尤其是某些新技术的应用和飞机系列化发展的需求,在充分吸收和借鉴传统飞机概念设计阶段起落架设计方法的基础上,从工程应用角度出发,总结并提出一套现代民用飞机概念设计阶段起落架接地点设计流程及方法。同时,按照设计流程将影响起落架接地点设计的限制因素划分为适航安全、性能、结构、空间布置、运营等影响因素,明晰各限制因素对设计产生的影响。%According to the design characteristics of advanced civil jet aircraft, especially about application of some new techniques and the requirements of family development, and based on traditional landing gear design method, the paper gives a study on a new design method of landing gear touchdown point in concept design phase from engineer design aspect. Meanwhile, following design steps, the restriction factors of landing gear touchdown point design are classified in safety, oerformance, structure, kinematics, ooeration, etc. Each restriction factor is clearlv described in the paner.

  20. Propulsion controlled aircraft computer

    Science.gov (United States)

    Cogan, Bruce R. (Inventor)

    2010-01-01

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

  1. CAD SIMULATION & FEM ANALYSIS OF AIRCRAFT LANDING GEAR MECHANISM

    OpenAIRE

    Nilesh W. Nirwan; Dilip G. Gangwani,

    2015-01-01

    Aircraft landing gear supports the entire weight of an aircraft during landing and ground operations. They are attached to primary structural members of the aircraft. The type of gear depends on the aircraft design and its intended use. Most landing gear has wheels to facilitate operation to and from hard surfaces, such as airport runways. Other gear feature skids for this purpose, such as those found on helicopters, balloon gondolas, and in the tail area of some tail dragger airc...

  2. Composite components on commercial aircraft

    Science.gov (United States)

    Dexter, H. B.

    1980-01-01

    The paper considers the use of composite components in commercial aircraft. NASA has been active in sponsoring flight service programs with advanced composites for the last 10 years, with 2.5 million total composite component hours accumulated since 1970 on commercial transports and helicopters with no significant degradation in residual strength of composite components. Design, inspection, and maintenance procedures have been developed; a major NASA/US industry technology program has been developed to reduce fuel consumption of commercial transport aircraft through the use of advanced composites.

  3. Hydrogen aircraft and airport safety

    International Nuclear Information System (INIS)

    First flight tests with a hydrogen demonstrator aircraft, currently under investigation in the scope of the German-Russia Cryoplane project, are scheduled for 1999. Regular service with regional aircraft may begin around 2005, followed by larger Airbus-type airliners around 2010-2015. The fuel storage aboard such airliners will be of the order of 15 t or roughly 200 m3 LH2. This paper investigates a number of safety problems associated with the handling and air transport of so much hydrogen. The same is done for the infrastructure on the airport. Major risks are identified, and appropriate measures in design and operation are recommended. It is found that hydrogen aircraft are no more dangerous than conventional ones - safer in some respects. (author)

  4. Database on aircraft accidents

    International Nuclear Information System (INIS)

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

  5. Dynamic grid technology for aircraft conceptual design%面向飞行器概念设计的动网格技术

    Institute of Scientific and Technical Information of China (English)

    王曼; 刘毅

    2013-01-01

    Based on the two dynamic grid methods (spring smooth approximation method and local remeshing method) and the function/shape function method,according to the facts that the program and the parameters change frequently at the phase of aircraft conceptual design,a dynamic grid method is proposed for the shape of the 2D airfoil.The method passes the changed boundary information to the grid,so that the grid is changed accordingly.Compared with the commonly used dynamic grid method,this method has better strength and resilience of the parameters performance,so the grid is generated fast.NACA 2415 airfoil,which adopts the "class function" and "shape function" translation technique (CST),is simulated in the case of low-speed turbulent flow under different angles of attack.The results show that the proposed dynamic grid technique can better simulate the flow characteristics of the airfoil and draw airfoil aerodynamic coefficients more accurately.The technique has good application value for parameter determination at the phase of aircraft conceptual design.%在弹簧近似光滑法和局部网格重构法两种动网格方法的基础上,结合类型函数/形状函数方法,针对飞行器概念设计阶段方案多变、参数变化快的特点,对二元机翼随参数变化的翼型提出了相适应的动网格方法.该方法根据参数的影响,将变动的边界信息传递到网格上,网格随之迭代变化.相对于常用动网格方法,该方法具有更强的参数表现力和适应力,使得网格生成更快速.对类型函数/形状函数转换方法(CST)拟合的NACA2415翼型在不同迎角情况下的低速湍流流动进行了数值模拟.计算结果表明,该动网格技术较好地模拟出了翼型的流动特性,较准确地得出了翼型的气动力系数,对飞行器概念设计阶段的参数确定具有实用价值,显示了该动网格方法的准确性和便捷性.

  6. 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)

    袁修起

    2014-01-01

    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。

  7. The Parametric Aircraft Noise Analysis Module - status overview and recent applications

    OpenAIRE

    Bertsch, Lothar; Guerin, Sebastien; Looye, Gertjan; Pott-Polenske, Michael

    2011-01-01

    The German Aerospace Center (DLR) is investigating aircraft noise prediction and noise reduction capabilities. The Parametric Aircraft Noise Analysis Module (PANAM) is a fast prediction tool by the DLR Institute of Aerodynamics and Flow Technology to address overall aircraft noise. It was initially developed to (1) enable comparative design studies with respect to overall aircraft ground noise and to (2) indentify promising low-noise technologies at early aircraft design stages. A brief surve...

  8. 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)

    孙健宇

    2016-01-01

    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。

  9. Design of Dual Electromechanical Actuator for Light Aircraft Landing Gear%小型飞机起落架双余度电动收放系统设计

    Institute of Scientific and Technical Information of China (English)

    李麟; 田威; 张霖

    2012-01-01

    起落架如何实现全电收放一直是全电飞机发展过程中的技术难题.为此,针对小型飞机起落架,研制了一种双余度电动收放作动筒.该电动作动筒具有直线收放、到位时锁定、收放时解锁和故障时应急放的功能.设计了一种电动收放系统双余度控制策略,并对其进行论述和分析.最后,通过试验对电动收放系统的功能和性能进行了验证,试验结果表明电动收放系统满足设计要求.%How to landing gear extend and retract electrically is always a key issue in all-electric aircraft development. A dual redundant electromechanical actuator is developed for light aircraft landing gear. The EMA has linear extension and retraction, lock and unlock, emergency extension capability. A control strategy based on dual electromechanical actuator is designed and analyzed. The experimental result shows that the electromechanical actuator meets the requirements of light aircraft landing gear actuator design.

  10. Small Aircraft RF Interference Path Loss Measurements

    Science.gov (United States)

    Nguyen, Truong X.; Koppen, Sandra V.; Ely, Jay J.; Szatkowski, George N.; Mielnik, John J.; Salud, Maria Theresa P.

    2007-01-01

    Interference to aircraft radio receivers is an increasing concern as more portable electronic devices are allowed onboard. Interference signals are attenuated as they propagate from inside the cabin to aircraft radio antennas mounted on the outside of the aircraft. The attenuation level is referred to as the interference path loss (IPL) value. Significant published IPL data exists for transport and regional category airplanes. This report fills a void by providing data for small business/corporate and general aviation aircraft. In this effort, IPL measurements are performed on ten small aircraft of different designs and manufacturers. Multiple radio systems are addressed. Along with the typical worst-case coupling values, statistical distributions are also reported that could lead to more meaningful interference risk assessment.

  11. Small Aircraft RF Interference Path Loss

    Science.gov (United States)

    Nguyen, Truong X.; Koppen, Sandra V.; Ely, Jay J.; Szatkowski, George N.; Mielnik, John J.; Salud, Maria Theresa P.

    2007-01-01

    Interference to aircraft radio receivers is an increasing concern as more portable electronic devices are allowed onboard. Interference signals are attenuated as they propagate from inside the cabin to aircraft radio antennas mounted on the outside of the aircraft. The attenuation level is referred to as the interference path loss (IPL) value. Significant published IPL data exists for transport and regional category airplanes. This report fills a void by providing data for small business/corporate and general aviation aircraft. In this effort, IPL measurements are performed on ten small aircraft of different designs and manufacturers. Multiple radio systems are addressed. Along with the typical worst-case coupling values, statistical distributions are also reported that could lead to better interference risk assessment.

  12. Altus aircraft on runway

    Science.gov (United States)

    1996-01-01

    The remotely piloted Altus aircraft flew several developmental test flights from Rogers Dry Lake adjacent to NASA's Dryden Flight Research Center, Edwards, Calif., in 1996. The Altus--the word is Latin for 'high'--is a variant of the Predator surveillance drone built by General Atomics/Aeronautical Systems, Inc. It is designed for high-altitude, long-duration scientific sampling missions, and is powered by a turbocharged four-cylinder piston engine. The first Altus was developed under NASA's Environmental Research Aircraft and Sensor Technology program, while a second Altus was built for a Naval Postgraduate School/Department of Energy program. A pilot in a control station on the ground flew the craft by radio signals, using visual cues from a video camera in the nose of the Altus and information from the craft's air data system. Equipped with a single-stage turbocharger during the 1996 test flights, the first Altus reached altitudes in the 37,000-foot range, while the similarly-equipped second Altus reached 43,500 feet during developmental flights at Dryden in the summer of 1997. The NASA Altus also set an endurance record of more than 26 hours while flying a science mission in late 1996 and still had an estimated 10 hours of fuel remaining when it landed. Now equipped with a two-stage turbocharger, the NASA Altus maintained an altitude of 55,000 feet for four hours during flight tests in 1999.

  13. Radial cylinder aircraft engines

    OpenAIRE

    Šimíček, Petr

    2015-01-01

    Práce je zaměřena na konstrukční řešení letadlových hvězdicových motorů. Úvod je pojednáním o historii letadlových hvězdicových motorů a jejich vývoji v historickém kontextu. Druhá část je zaměřena na konstrukci letadlových hvězdicových motorů, následně jsou uvedena některá zajímavá konstrukční řešení a porovnání s motorem jiného druhu konstrukce. The bachelor's thesis is focused on design of aircraft radial engines. Home is a treatise on the history of aircraft radial engines and their de...

  14. Integrated Network of Optimizations for Aircraft Systems Project

    Data.gov (United States)

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

  15. Design and Simulation of Adaptive Active Noise Control System for Aircraft Helmet%飞行头盔主动噪声控制系统的设计及仿真研究

    Institute of Scientific and Technical Information of China (English)

    唐红; 王明皓; 吴凤霞

    2011-01-01

    Aiming at solving low frequency noise existing in cockpit,a design for adaptive active noise control system of aircraft helmet is proposed. Based on it,the filtered-XLMS algoritbm is simulated and analysed using MATLAB.The result shows that the effect of reducing aircraft noise on low frequency is very satisfactory with the scheme.%针对飞机驾驶舱内存在着大量的低频噪声,提出一种应用于飞行员头盔的自适应有源噪声控制系统设计方案,并在此基础上,利用MATLAB对FXLMS算法进行了仿真和性能分析。结果表明,此方案对飞机噪声低频段具有很好的降噪效果。

  16. Turboelectric Aircraft Drive Key Performance Parameters and Functional Requirements

    Science.gov (United States)

    Jansen, Ralph H.; Brown, Gerald V.; Felder, James L.; Duffy, Kirsten P.

    2016-01-01

    The purpose of this paper is to propose specific power and efficiency as the key performance parameters for a turboelectric aircraft power system and investigate their impact on the overall aircraft. Key functional requirements are identified that impact the power system design. Breguet range equations for a base aircraft and a turboelectric aircraft are found. The benefits and costs that may result from the turboelectric system are enumerated. A break-even analysis is conducted to find the minimum allowable electric drive specific power and efficiency that can preserve the range, initial weight, operating empty weight, and payload weight of the base aircraft.

  17. Subsonic Aircraft Safety Icing Study

    Science.gov (United States)

    Jones, Sharon Monica; Reveley, Mary S.; Evans, Joni K.; Barrientos, Francesca A.

    2008-01-01

    NASA's Integrated Resilient Aircraft Control (IRAC) Project is one of four projects within the agency s Aviation Safety Program (AvSafe) in the Aeronautics Research Mission Directorate (ARMD). The IRAC Project, which was redesigned in the first half of 2007, conducts research to advance the state of the art in aircraft control design tools and techniques. A "Key Decision Point" was established for fiscal year 2007 with the following expected outcomes: document the most currently available statistical/prognostic data associated with icing for subsonic transport, summarize reports by subject matter experts in icing research on current knowledge of icing effects on control parameters and establish future requirements for icing research for subsonic transports including the appropriate alignment. This study contains: (1) statistical analyses of accident and incident data conducted by NASA researchers for this "Key Decision Point", (2) an examination of icing in other recent statistically based studies, (3) a summary of aviation safety priority lists that have been developed by various subject-matter experts, including the significance of aircraft icing research in these lists and (4) suggested future requirements for NASA icing research. The review of several studies by subject-matter experts was summarized into four high-priority icing research areas. Based on the Integrated Resilient Aircraft Control (IRAC) Project goals and objectives, the IRAC project was encouraged to conduct work in all of the high-priority icing research areas that were identified, with the exception of the developing of methods to sense and document actual icing conditions.

  18. Schlieren Imaging Of An Aircraft In Flight

    Science.gov (United States)

    Weinstein, Leonard M.

    1994-01-01

    Technique for making schlieren images of airplanes and missiles in supersonic flight devised to help understand physics of compressible aerodynamic flows about complicated aircraft shapes. Technique also used to study far-field sonic booms. Data obtained from schlieren images useful in optimizing designs of prototype aircraft. Technique incorporates elements of focusing schlieren photography, astronomical photography, and streak photography. Using sun or moon as source of light, apparatus forms image revealing gradients of density in air flow.

  19. Crashworthiness of composite seats for civil aircraft

    OpenAIRE

    Stephens, V. M.

    1992-01-01

    A study has been conducted into the design of civil aircraft seats which are forward-facing and use the lap-belt method of restraint. Within these terms of reference, the response of the seat restraint occupant system (SROS) to impact loading has been analysed using physical (dynamic testing) and analytical (computer simulation) modelling techniques. With the increasing use of fibre-reinforced polymer composites in aircraft for weight efficiency, and the consequent appearance of composite se...

  20. Model-based synthesis of aircraft noise to quantify human perception of sound quality and annoyance

    Science.gov (United States)

    Berckmans, D.; Janssens, K.; Van der Auweraer, H.; Sas, P.; Desmet, W.

    2008-04-01

    This paper presents a method to synthesize aircraft noise as perceived on the ground. The developed method gives designers the opportunity to make a quick and economic evaluation concerning sound quality of different design alternatives or improvements on existing aircraft. By presenting several synthesized sounds to a jury, it is possible to evaluate the quality of different aircraft sounds and to construct a sound that can serve as a target for future aircraft designs. The combination of using a sound synthesis method that can perform changes to a recorded aircraft sound together with executing jury tests allows to quantify the human perception of aircraft noise.

  1. Design and programming of the software to control the sensor and sensorless BLDCM of the electrical propulsion system for the solar aircraft

    OpenAIRE

    Armero Almazán, Pablo

    2013-01-01

    A Brushless Direct Current (BLDC) machine and converter are applied for the electric propulsion system of the solar aircraft. BLDC motors are electronically commutated instead of mechanically, as Direct Current (DC) motors do, so the position of the rotor must be known to do the commutation at the right moment. The control of BLDC motors can be done in sensor or sensorless mode. being the use of Hall-effect sensors the most widespread use inside the sensored control. The use of th...

  2. Static mechanical properties of 30 x 11.5-14.5, type VII, aircraft tires of bias-ply and radial-belted design

    Science.gov (United States)

    Davis, Pamela A.; Lopez, Mercedes C.

    1987-01-01

    An investigation was conducted to determine the static mechanical characteristics of 30 x 115-14.5 bias-ply and radial aircraft tires. The tires were subjected to vertical and lateral loads and mass moment of inertia tests were conducted. Static load deflection curves, spring rates, hysteresis losses, and inertia data are presented along with a discussion of the advantages and disadvantages of one tire over the other.

  3. Static mechanical properties of 30 x 11.5 - 14.5, type 8 aircraft tires of bias-ply and radial-belted design

    Science.gov (United States)

    Davis, Pamela A.; Lopez, Mercedes C.

    1988-01-01

    An investigation was conducted to determine the static mechanical properties of a 30 x 11.5 to 14.5, Type 8, bias-ply and radial-belted aircraft tire. The properties measured were the spring rate and damping characteristics of each tire from vertical- and lateral-loading hysteresis loops. Mass moment of inertia tests were also conducted. The results of the study are presented along with a discussion of the advantages and disadvantages of each type of tire.

  4. Survival analysis of aging aircraft

    Science.gov (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.

  5. Control of Next Generation Aircraft and Wind Turbines

    Science.gov (United States)

    Frost, Susan

    2010-01-01

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

  6. Aircraft impact on a spherical shell

    International Nuclear Information System (INIS)

    For nuclear power plants located in the immediate vicinity of cities and airports safeguarding against an accidental aircraft strike is important. Because of the complexity of such an aircraft crash the building is ordinarily designed for loading by an idealized dynamical load F(t), which follows from measurements (aircraft striking a rigid wall). The extent to which the elastic displacements of a structure influence the impact load F(t) is investigatd in this paper. The aircraft is idealized by a linear mass-spring-dashpot combination which can easily be treated in computations and which can suffer elastic as well as plastic deformations. This 'aircraft' normally strikes a spherical shell at the apex. The time-dependent reactions of the shell as a function of the unknown impact load F(t) are expanded in terms of the normal modes, which are Legendre functions. The continuity condition at the impact point leads to an integral equation for F(t) which may be solved by Laplace transformation. F(t) is computed for hemispheres with several ratios of thickness to radius, several edge conditions and several 'aircraft' parameters. In all cases F(t) differs very little from that function obtained for the case of the aircraft striking a rigid wall. (Auth.)

  7. Aircraft bi-level life cycle cost estimation

    NARCIS (Netherlands)

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

    2015-01-01

    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

  8. Robust Control of an Ill-Conditioned Aircraft

    DEFF Research Database (Denmark)

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

    1996-01-01

    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....

  9. Vulnerability of fighter–aircraft for new threats

    NARCIS (Netherlands)

    Meerten, E. van

    2002-01-01

    Technical developments in modern fighter aircraft design will contribute to aircraft survivability by influencing either the aircraft’s susceptibility or its vulnerability. On the other hand, technical developments in missile warhead and ammunition design will result in a lethality increase against

  10. The drive for Aircraft Energy Efficiency

    Science.gov (United States)

    James, R. L., Jr.; Maddalon, D. V.

    1984-01-01

    NASA's Aircraft Energy Efficiency (ACEE) program, which began in 1976, has mounted a development effort in four major transport aircraft technology fields: laminar flow systems, advanced aerodynamics, flight controls, and composite structures. ACEE has explored two basic methods for achieving drag-reducing boundary layer laminarization: the use of suction through the wing structure (via slots or perforations) to remove boundary layer turbulence, and the encouragement of natural laminar flow maintenance through refined design practices. Wind tunnel tests have been conducted for wide bodied aircraft equipped with high aspect ratio supercritical wings and winglets. Maneuver load control and pitch-active stability augmentation control systems reduce fuel consumption by reducing the drag associated with high aircraft stability margins. Composite structures yield lighter airframes that in turn call for smaller wing and empennage areas, reducing induced drag for a given payload. In combination, all four areas of development are expected to yield a fuel consumption reduction of 40 percent.

  11. Mission management for unmanned aircraft systems

    OpenAIRE

    Valenzuela Arroyo, Marta

    2011-01-01

    The goal of this project is to design and implement a mission manager for unmanned aircraft systems. The mission manager will work under the USAL architecture designed by the ICARUS UAV group at the EPSC. The student will be able to learn programming skills, working with a group, and research.

  12. Investigation of cross flow fan propulsion for lightweight VTOL aircraft.

    OpenAIRE

    Gossett, Dean H.

    2000-01-01

    As world population increases, road and airport congestion will become increasingly prevalent. A small, cheap vTOL aircraft which can be flown from a driveway to the workplace parking lot would reduce traffic congestion and travel time. A lightweight, single seat commuter type VTOL aircraft is envisioned as the solution to this problem. To achieve a goal of minimum weight, the aircraft aerodynamic design should be optimized for forward flight. Vertical thrust augmentation from a propulsion un...

  13. Dynamically Scaled Modular Aircraft for Flight-Based Aviation Safety Research Project

    Data.gov (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...

  14. Development of an approach and tool to improve the conceptual design process of the wing box structure of low-subsonic transport aircraft

    OpenAIRE

    Syamsudin, Hendri

    2009-01-01

    To produce a better airframe design, it is imperative to investigate the problems of design and manufacturing integration early on at the conceptual design stage. A new design approach and support tool is required which will aid the designer in future product development. This is a particular necessity in the current context of increasing complexity and challenging economic situations. The present work focuses on the development of a design approach and design aids for designing metallic w...

  15. 破解双寡头垄断的商用大飞机定价策略设计%Pricing Strategy Design of Commercial Large Aircraft for the Double Oligopoly

    Institute of Scientific and Technical Information of China (English)

    张素嵘; 方志耕

    2015-01-01

    在短期内,全球商用大飞机市场处于波音和空客公司的双寡头垄断格局。大型商用飞机的定价策略设计应以双寡头垄断的市场为背景,同时需要考虑主制造商、各国政府、航空公司、消费者和金融服务机构等多主体的利益。因此,采用冲突分析建模,分析各主体对不同可行策略集的偏好,确定冲突的最可能解,提出商用大飞机主制造商的动态调整定价机制。%In the short term, the global commercial aircraft market are in the double oligopoly market of Boeing and Airbus Company. The pricing strategy design of large commercial aircraft should be based on the market of double oligopoly market. The interests of the main manufacturers, governments, airlines, consumers and financial services and other multi-agents also need to be considered. Therefore, the conflict analysis is used to analyze the multi-agents preference of the different feasible strategy sets and the most likely solution of the conflict is determined. Then the dynamic adjustment pricing mechanism of the large commercial aircraft's main manufacturers is proposed.

  16. Aircraf landing gear design in respect of pavement design

    OpenAIRE

    Fabre, C.; ALBIN, A; Balay, Jean Maurice

    2009-01-01

    This paper considers the close relationship between aircraft landing gear (LG) and pavement design in respect of airfield pavement compatibility. In pavement design and analysis, we usually deal with pavement structures, materials and design thickness procedure but rarely aircraft LG design This paper emphasizes key drivers, which must be considered for new aircraft LG design to achieve aircraft pavement compatibility. Several parameters such as number & size of wheels, type of gear, brakes, ...

  17. 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)

    李炜宇

    2012-01-01

    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.

  18. 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.

    2003-11-01

    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.

  19. Optimization Design For Air Conditioning System of A Light Business Aircraft%某轻型公务机空调系统优化设计分析

    Institute of Scientific and Technical Information of China (English)

    刘登程

    2015-01-01

    The analysis and calculation of the NACA inlet of a light business aircraft shows the problem of the air conditioning system, which the cabin supply air temperature is too high in the high temperature conditions. This paper gives an optimization solution to solve the problem, also improves the performance of the air conditioning system.%通过对某轻型公务机空调系统NACA进气口的性能分析与计算,了解NACA进气口在地面热设计状态下存在的问题,并针对此问题提出可行的优化设计方案,提高空调系统的性能.

  20. Antifreeze Polysaccharide Coating Study for De-icing Aircraft

    Science.gov (United States)

    Morita, Katsuaki; Sakaue, Hirotaka; Ando, Azuma; Matsuda, Yoshiyuki; Kawahara, Hidehisa

    2015-11-01

    Anti-icing or deicing of an aircraft is necessary for a safe flight operation. Mechanical processes, such as heating and deicer boot, are widely used. Deicing fluids, such as propyrene glycol and ethylene glycol, are used to coat the aircraft. However, these should be coated every time before the take-off, since the fluids come off from the aircraft while cruising. We study an antifreeze polysaccharide (AFPS) coating as a deicer for an aircraft. It is designed to coat on the aircraft without removal. Since an AFPS coating removes ice by reducing the interfacial energy, it would be an alternative way to prevent ice on the aircraft. We provide a temperature-controlled room, which can control its temperature under icing conditions (-8 and -4 °C). Ice adhesion tests are performed for AFPS coating and compared with a fundamental specimen without the coating.

  1. Depreciation of aircraft

    Science.gov (United States)

    Warner, Edward P

    1922-01-01

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

  2. Aircraft Fire Protection Laboratory

    Data.gov (United States)

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

  3. Solar thermal aircraft

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, Charles L. (Livermore, CA)

    2007-09-18

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

  4. AIRTV: Broadband Direct to Aircraft

    Science.gov (United States)

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

    2002-01-01

    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

  5. Program for establishing long time flight service performance of composite materials in the central wing structure of C-130 aircraft. Phase 2: Detailed design

    Science.gov (United States)

    Harvill, W. E.; Duhig, J. J.; Spencer, B. R.

    1973-01-01

    The design, fabrication, and evaluation of boron-epoxy reinforced C-130 center wing boxes are discussed. Design drawings, static strength, fatigue endurance, flutter, and weight analyses required for the wing box fabrication are presented. Additional component testing to verify the design for panel buckling and to evaluate specific local design areas are reported.

  6. Control strategies for aircraft airframe noise reduction

    Institute of Scientific and Technical Information of China (English)

    Li Yong; Wang Xunnian; Zhang Dejiu

    2013-01-01

    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.

  7. Digital adaptive control laws for VTOL aircraft

    Science.gov (United States)

    Hartmann, G. L.; Stein, G.

    1979-01-01

    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.

  8. Aircraft Electric Propulsion Systems Applied Research at NASA

    Science.gov (United States)

    Clarke, Sean

    2015-01-01

    Researchers at NASA are investigating the potential for electric propulsion systems to revolutionize the design of aircraft from the small-scale general aviation sector to commuter and transport-class vehicles. Electric propulsion provides new degrees of design freedom that may enable opportunities for tightly coupled design and optimization of the propulsion system with the aircraft structure and control systems. This could lead to extraordinary reductions in ownership and operating costs, greenhouse gas emissions, and noise annoyance levels. We are building testbeds, high-fidelity aircraft simulations, and the first highly distributed electric inhabited flight test vehicle to begin to explore these opportunities.

  9. Fore and aft elastic response characteristics of size 34x9.9, type 7, 14 ply-rated aircraft tires of bias ply, bias belted, and radial belted design. M.S. Thesis - George Washington Univ., Washington, D. C.

    Science.gov (United States)

    Tanner, J. A.

    1973-01-01

    An investigation was conducted to determine the fore-and-aft elastic response characteristics of aircraft tires of bias ply, bias-belted, and radial-belted design. The investigation consisted of: (1)static and rolling tests, (2)a statistical analysis which related the measured tire elastic characteristics to variations in the vertical load, inflation pressure, braking force and/or tire vertical deflection, and (3) a semi-empirical analysis which related the tire elastic behavior to measured wheel slippage during a steady-state braking. The results of this investigation indicate that the bias-belted tire has the largest spring constant value for most loading conditions and the radial-belted tire has the smallest spring constant value.

  10. PREDICTION OF AIRCRAFT NOISE LEVELS

    Science.gov (United States)

    Clark, B. J.

    1994-01-01

    Methods developed at the NASA Lewis Research Center for predicting the noise contributions from various aircraft noise sources have been incorporated into a computer program for predicting aircraft noise levels either in flight or in ground test. The noise sources accounted for include fan inlet and exhaust, jet, flap (for powered lift), core (combustor), turbine, and airframe. Noise propagation corrections are available in the program for atmospheric attenuation, ground reflections, extra ground attenuation, and shielding. The capacity to solve the geometrical relationships between an aircraft in flight and an observer on the ground has been included in the program to make it useful in evaluating noise estimates and footprints for various proposed engine installations. The program contains two main routines for employing the noise prediction routines. The first main routine consists of a procedure to calculate at various observer stations the time history of the noise from an aircraft flying at a specified set of speeds, orientations, and space coordinates. The various components of the noise are computed by the program. For each individual source, the noise levels are free field with no corrections for propagation losses other than spherical divergence. The total spectra may then be corrected for the usual effects of atmospheric attenuation, extra ground attenuation, ground reflection, and aircraft shielding. Next, the corresponding values of overall sound pressure level, perceived noise level, and tone-weighted perceived noise level are calculated. From the time history at each point, true effective perceived noise levels are calculated. Thus, values of effective perceived noise levels, maximum perceived noise levels, and tone-weighted perceived noise levels are found for a grid of specified points on the ground. The second main routine is designed to give the usual format of one-third octave sound pressure level values at a fixed radius for a number of user

  11. 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

    2012-01-01

    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.

  12. Information note about the protection of nuclear facilities against aircraft crashes

    International Nuclear Information System (INIS)

    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). 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.)

  13. AIRTV: Broadband Direct to Aircraft

    Science.gov (United States)

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

    2002-01-01

    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

  14. Fundamentals of aircraft and rocket propulsion

    CERN Document Server

    El-Sayed, Ahmed F

    2016-01-01

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

  15. Electronic materials testing in commercial aircraft engines

    Science.gov (United States)

    Brand, Dieter

    A device for the electronic testing of materials used in commercial aircraft engines is described. The instrument can be used for ferromagnetic, ferrimagnetic, and nonferromagnetic metallic materials, and it functions either optically or acoustically. The design of the device is described and technical data are given. The device operates under the principle of controlled self-inductivity. Its mode of operation is described.

  16. Recognition of aircraft using HRR features

    NARCIS (Netherlands)

    Kossen, A.S.

    2008-01-01

    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

  17. Perspectives of civil aircraft avionics development

    OpenAIRE

    Наумов, А. В.

    1999-01-01

    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

  18. IDENTIFICATION OF AIRCRAFT HAZARDS

    International Nuclear Information System (INIS)

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

  19. IDENTIFICATION OF AIRCRAFT HAZARDS

    Energy Technology Data Exchange (ETDEWEB)

    K.L. Ashley

    2005-03-23

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

  20. Identification of Aircraft Hazards

    Energy Technology Data Exchange (ETDEWEB)

    K. Ashley

    2006-12-08

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

  1. Aircraft Operations Classification System

    Science.gov (United States)

    Harlow, Charles; Zhu, Weihong

    2001-01-01

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

  2. Identification of Aircraft Hazards

    International Nuclear Information System (INIS)

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

  3. Considerations of Unmanned Aircraft Classification for Civil Airworthiness Standards

    Science.gov (United States)

    Maddalon, Jeffrey M.; Hayhurst, Kelly J.; Morris, A. Terry; Verstynen, Harry A.

    2013-01-01

    The use of unmanned aircraft in the National Airspace System (NAS) has been characterized as the next great step forward in the evolution of civil aviation. Although use of unmanned aircraft systems (UAS) in military and public service operations is proliferating, civil use of UAS remains limited in the United States today. This report focuses on one particular regulatory challenge: classifying UAS to assign airworthiness standards. Classification is useful for ensuring that meaningful differences in design are accommodated by certification to different standards, and that aircraft with similar risk profiles are held to similar standards. This paper provides observations related to how the current regulations for classifying manned aircraft, based on dimensions of aircraft class and operational aircraft categories, could apply to UAS. This report finds that existing aircraft classes are well aligned with the types of UAS that currently exist; however, the operational categories are more difficult to align to proposed UAS use in the NAS. Specifically, the factors used to group manned aircraft into similar risk profiles do not necessarily capture all relevant UAS risks. UAS classification is investigated through gathering approaches to classification from a broad spectrum of organizations, and then identifying and evaluating the classification factors from these approaches. This initial investigation concludes that factors in addition to those currently used today to group manned aircraft for the purpose of assigning airworthiness standards will be needed to adequately capture risks associated with UAS and their operations.

  4. Aerodynamics/ACEE: Aircraft energy efficiency

    Science.gov (United States)

    1981-01-01

    An overview is presented of a 10 year program managed by NASA which seeks to make possible the most efficient use of energy for aircraft propulsion and lift as well as provide a technology that can be used by U.S. manufacturers of air transports and engines. Supercritical wings, winglets, vortex drag reduction, high lift, active control, laminar flow control, and aerodynamics by computer are among the topics discussed. Wind tunnel models in flight verification of advanced technology, and the design, construction and testing of various aircraft structures are also described.

  5. Aircraft concepts for service to small communities

    Science.gov (United States)

    Galloway, T. L.

    1976-01-01

    Small communities are served by trunk, local-service, and commuter carriers having a wide variety in route structure, type of service, and economic character, operating over stage lengths less than 400 statute miles. NASA studies have investigated various aircraft concepts for short-haul that have potential in this market area. Aircraft concepts for this market require a careful balancing of performance, technology, and design-to-cost considerations. This paper summarizes some results of recent NASA sponsored air transportation system studies applicable to small community arenas.

  6. SAFETY DESIGN AERONAUTICAL ENGINEERING

    Directory of Open Access Journals (Sweden)

    Aleksandr Tamargazin

    2012-09-01

    Full Text Available  The article deals with contemporary issues of safety of aircraft structures, which are fundamental in the choice of approaches to the continuing airworthiness of aircraft which re fundamental in the choice of approaches to continuing airworthiness of aircraft. The features of the formation methods of technical maintenance of aircraft in view of the design type are considered. Experience of aircraft maintenance has shown that the use of combined operational vitality in a number of cases has helped to prevent the catastrophic destruction of aircraft at a time when high enough qualifications for airline personnel were not satisfied.

  7. Altus I aircraft on lakebed

    Science.gov (United States)

    1997-01-01

    The remotely-piloted Altus I aircraft climbs away after takeoff from Rogers Dry Lake adjacent to NASA's Dryden Flight Research Center, Edwards, Calif. The short series of test flights sponsored by the Naval Postgraduate School in early August, 1997, were designed to demonstrate the ability of the experimental craft to cruise at altitudes above 40,000 feet for sustained durations. On its final flight Aug. 15, the Altus I reached an altitude of 43,500 feet. The Altus I and its sister ship, the Altus II, are variants of the Predator surveillance drone built by General Atomics/Aeronautical Systems, Inc. They are designed for high-altitude, long-duration scientific sampling missions, and are powered by turbocharged piston engines. The Altus I incorporates a single-stage turbocharger, while the Altus II, built for NASA's Environmental Research Aircraft and Sensor Technology program, sports a two-stage turbocharger to enable the craft to fly at altitudes above 55,000 feet. The Altus II, the first of the two craft to be completed, made its first flight on May 1, 1996. With its engine augmented by a single-stage turbocharger, the Altus II reached an altitude of 37,000 ft during its first series of development flights at Dryden in Aug., 1996. In Oct. of that year, the Altus II was flown in an Atmospheric Radiation Measurement study for the Department of Energy's Sandia National Laboratory in Oklahoma. During the course of those flights, the Altus II set a single-flight endurance record for remotely-operated aircraft of more than 26 hours. The Altus I, completed in 1997, flew a series of development flights at Dryden that summer. Those test flights culminated with the craft reaching an altitude of 43,500 ft while carrying a simulated 300-lb payload, a record for an unmanned aircraft powered by a piston engine augmented with a single-stage turbocharger. The Altus II sustained an altitudeof 55,000 feet for four hours in 1999. A pilot in a control station on the ground flies the

  8. Hazards from aircraft

    International Nuclear Information System (INIS)

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

  9. Robotic aircraft scanner for neutron radiographic inspection

    International Nuclear Information System (INIS)

    A robotic positioner and manipulator, a key component of a mobile neutron radiography system (MNRS) for aircraft inspection, is described. The MNRS is designed to inspect military aircraft for hidden corrosion in aluminum structures. The MNRS is comprised of an accelerator-based (Kaman A-711 sealed tube neutron generator using the deuterium-tritium reaction) thermal neutron source, electronic neutron imaging system, robotic positioner and manipulator for the source/imager, control trailer housing system control electronics and digital image processing system, mobile dark room for film processing, self-contained electrical power source, and radiation safety system. For in situ aircraft inspection, the robotic scanner is programmed (in a teach/learn mode) to scan a region of the components (e.g., wings, stabilizers, etc.) using a control pendant

  10. Small Autonomous Aircraft Servo Health Monitoring

    Science.gov (United States)

    Quintero, Steven

    2008-01-01

    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.

  11. Advanced Aircraft Material

    Directory of Open Access Journals (Sweden)

    Vivek Kumar Prince

    2013-06-01

    Full Text Available There has been long debate on “advanced aircraft material” from past decades & researchers too came out with lots of new advanced material like composites and different aluminum alloys. Now days a new advancement that is in great talk is third generation Aluminum-lithium alloy. Newest Aluminum-lithium alloys are found out to have low density, higher elastic modulus, greater stiffness, greater cryogenic toughness, high resistance to fatigue cracking and improved corrosion resistance properties over the earlier used aircraft material as mentioned in Table 3 [1-5]. Comparison had been made with nowadays used composite material and is found out to be more superior then that

  12. 战斗机战术技术要求的分析和全机重量的计算%An Accurate Estimate of Take-off Weight of Fighter Aircraft at Conceptual Design Stage

    Institute of Scientific and Technical Information of China (English)

    杨华保

    2001-01-01

    在对战术技术要求指标分类的基础上,提出了用重量分析法进行战术技术要求分析的方法;对全机重量的计算进行了研究,提出了用统计方法计算空机重量和用对飞行剖面分段计算燃油重量的方法。经过实际型号的验算,证明方法可行,结果令人满意。%I developed a software for estimating take-off weight of fighter aircraft according to tactical and technical requirements at the conceptual design stage. Take-off weight consists of empty weight, fuel weight and payload weight. Estimating take-off weight is an iterative process, as many factors including empty weight, fuel weight and tactical and technical requirements, are related to take-off weight. In my software, empty weight can be calculated from take-off weight by a formula deduced from statistical data relating empty weight to take-off weight. In estimating fuel weight, I divide the mission profile into several basic segments and calculate the fuel consumption of each basic segment. My software can make the iterative process of accurately estimating take-off weight of a fighter aircraft quite easy. Data of some existing fighters confirm preliminarily that my software is reliable.

  13. Designing a New Nonlinear PID Attitude Controller for Small Quad-rotor Aircraft%小型四旋翼飞行器新型非线性PID姿态控制器设计

    Institute of Scientific and Technical Information of China (English)

    李杰; 齐晓慧; 韩帅涛

    2013-01-01

    针对小型四旋翼飞行器姿态控制问题,设计了一种新型非线性PID姿态控制器.针对传统PID的不足,通过引入两个跟踪微分器以及误差反馈的非线性组合构成非线性PID,并结合简化的小型四旋翼飞行器数学模型,提出了一种基于新型非线性PID姿态控制方法.仿真结果表明,所设计的控制器具有较强的鲁棒性、抗干扰性以及良好的滤波性能,系统具有良好的动态和稳态性能.由于保留了传统PID优点,设计简单,对实际工程具有较大的指导价值.%A new nonlinear PID attitude controller was designed to control the attitude of a small quad-rotor aircraft.Combined with the simplified mathematical model of small quad-rotor aircraft,an attitude control method was proposed by using the new nonlinear PID attitude controller.Two tracking differentiators and a nonlinear state error feedback are used to overcome the deficiency of the traditional PID controller.The simulation results indicate that our attitude controller achieves strong robustness,anti-disturbance and high filtering performances,having high-dynamic and steady-state performances.

  14. LQR in control law design for a relaxed static stability large civil aircraft%放宽静稳定性大型客机的LQR控制律设计

    Institute of Scientific and Technical Information of China (English)

    王一超; 江驹; 王新华; 甄子洋; 李欣

    2012-01-01

    Feedback of normal overload in the autopilot' s inner loop of longitudinal control law can form the C-star control configuration for the relaxed static stability large civil aircraft and increase its static stability. In this article , the output-feedback tracker closes the inner loop, the attitude loop and the thrust loop simultaneously by means of the LQR method. The nonlinear model of B707 civil aircraft is established, trimmed and linearized. After the control parameters are designed, the digital simulation is performed. The simulation results show that the transient and steady-state responses are satisfactory. And the augmentation effect meets the requirements well.%论述了法向过载信号反馈在放宽静稳定性大型客机自动驾驶仪增稳控制中的作用.在自动驾驶仪纵向内回路控制律中引入法向过载信号,构成了国际先进客机的C*控制律构型;反馈系统的输出信号,选用LQR设计方法同时闭合客机纵向的内回路和姿态、油门回路,形成了输出跟踪器,并设计了性能指标与反馈参数.以B707为例,建立了其着陆进近阶段的非线性模型,配平并线性化,用获得的控制律进行数字仿真验证.结果表明,内回路增稳效果良好,C*响应曲线在最佳响应区,姿态响应和速度保持都达到了满意的效果.

  15. Method of airport concrete pavement design for large military transport aircrafts%适应大型特种飞机的机场水泥混凝土道面结构设计方法

    Institute of Scientific and Technical Information of China (English)

    李巧生; 赵鸿铎; 凌建明

    2011-01-01

    对适应大型特种飞机的机场水泥混凝土道面的损坏模式、设计标准和厚度计算方法进行研究.明确了大型特种飞机荷载重、起落架复杂的特点;三维有限元分析的结果表明,其多轮叠加效应明显,建议在道面结构设计中考虑全起落架荷载.针对大型特种飞机的特点提出以9块板二维有限元模型作为力学分析模型,以板疲劳断裂作为损坏模式,基于累积损伤原理考虑混合交通.基于Miner原理,给出了累积损伤因子CDF的计算公式,并以CDF接近1(道面达到50%的开裂密度)作为道面设计标准.详细分析了不同机型通行一覆盖率的计算方法,以此为基础形成了各机型预期覆盖次数的计算方法.系统对比了国内外的水泥混凝土道面疲劳方程,建议以美国NCHRPI-26提出的疲劳方程作为现阶段构建水泥混凝土道面设计方法的基础,并进一步明确了允许覆盖次数的计算方法.综合提出了适应大型特种飞机的机场水泥混凝土道面结构设计流程.%This paper is about airport concrete pavement design method for large special aircrafts. Based on 3-D FEM analysis, full landing gear is recommended for pavement design. Considering the characteristics of large special aircrafts,a 3-D FEM model with 9 concrete slabs is employed for pavement design. Fatigue crack is taken as a damage pattern,and a cumulative principle is recommended to consider mixed traffic. Based on Miner's principle, the functions of calculating CDF are given. CDF = 1 is accepted as the design criteria of concrete pavement, which indicates 50% crack density. The P/C (pass to coverage ratio) calculation functions are put forwarded for various aircrafts, and the equation for calculating the expected coverage is developed. Various fatigue functions of airport concrete pavement are compared.The functions developed by NCHRP 1-26 are accepted as the fatigue functions to calculate the allowable coverage of

  16. A NASA study of the impact of technology on future sea based attack aircraft

    Science.gov (United States)

    Hahn, Andrew S.

    1992-01-01

    A conceptual aircraft design study was recently completed evaluating carrier-based, subsonic attack aircraft using contemporary and future technology assumptions. The study examined a configuration matrix that was made up of light and medium bomb loads, one and two man crews, internal and external weapons carriage, as well as conventional and flying wing planforms. Use of common technology assumptions, engine cycle simulation code, design mission, and consistent application of methods allow for direct comparison of the aircraft. This paper describes the design study ground rules and the aircraft designed. The aircraft descriptions include weights, dimensions, layout, design mission, design constraints, maneuver performance, and fallout mission performance. The strengths, and weaknesses of each aircraft are highlighted.

  17. A strategic planning methodology for aircraft redesign

    Science.gov (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

  18. Optical communications for transport aircraft

    Science.gov (United States)

    Stengel, Robert

    1994-01-01

    Optical communications for transport aircraft are discussed. The problem involves: increasing demand for radio-frequency bands from an enlarging pool of users (aircraft, ground and sea vehicles, fleet operators, traffic control centers, and commercial radio and television); desirability of providing high-bandwidth dedicated communications to and from every aircraft in the National Airspace System; need to support communications, navigation, and surveillance for a growing number of aircraft; and improved meteorological observations by use of probe aircraft. The solution involves: optical signal transmission support very high data rates; optical transmission of signals between aircraft, orbiting satellites, and ground stations, where unobstructed line-of-sight is available; conventional radio transmissions of signals between aircraft and ground stations, where optical line-of-sight is unavailable; and radio priority given to aircraft in weather.

  19. Long Range Aircraft Trajectory Prediction

    OpenAIRE

    Magister, Tone

    2009-01-01

    The subject of the paper is the improvement of the aircraft future trajectory prediction accuracy for long-range airborne separation assurance. The strategic planning of safe aircraft flights and effective conflict avoidance tactics demand timely and accurate conflict detection based upon future four–dimensional airborne traffic situation prediction which is as accurate as each aircraft flight trajectory prediction. The improved kinematics model of aircraft relative flight considering flight ...

  20. Aircraft landing gear extension and retraction control system diagnostics, prognostics and health management

    OpenAIRE

    Yang, Yang

    2012-01-01

    This thesis contains the Group Design Project (GDP) work and Individual Research Project (IRP) work. The target of this GDP was to design a long range flying wing passenger aircraft to meet the increasing global aircraft demand. The name of this flying wing aircraft is FW-11. This is a project cooperated between Aviation Industry Corporation of China (AVIC) and Cranfield University. The writer was involved in the conceptual design stage of this project. The author was in cha...

  1. Aircraft noise prediction

    Science.gov (United States)

    Filippone, Antonio

    2014-07-01

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

  2. DYNAMIC RESPONSE ANALYSIS OF CARRIER-BASED AIRCRAFT DURING LANDING

    Institute of Scientific and Technical Information of China (English)

    段萍萍; 聂宏; 魏小辉

    2013-01-01

    In view of the complexity of landing on the deck of aircraft carrier ,a systematic model ,composed of six-degree-of-freedom mathematic model of carrier-based aircraft ,four-degree-of-freedom model of landing gears and six-degree-of-freedom mathematic model of carrier , is established in the Matlab-Simulink environment , with damping function of landing gears and dynamic characteristics of tires being considered .The model ,where the car-rier movement is introduced ,is applicable for any abnormal landing condition .Moreover ,the equations of motion and relevant parameter are also derived .The dynamic response of aircraft is calculated via the variable step-size Runge-Kuta algorithm .The effect of attitude angles of aircraft and carrier movement during the process of landing is illustrated in details .The analytical results can provide some reference for carrier-based aircraft design and main-tenance .

  3. Effects of aircraft noise on flight and ground structures

    Science.gov (United States)

    Mixson, J. S.; Mayes, W. H.; Willis, C. M.

    1976-01-01

    Acoustic loads measured on jet-powered STOL configurations are presented for externally blown and upper surface blown flap models ranging in size from a small laboratory model up to a full-scale aircraft model. The implications of the measured loads for potential acoustic fatigue and cabin noise are discussed. Noise transmission characteristics of light aircraft structures are presented. The relative importance of noise transmission paths, such as fuselage sidewall and primary structure, is estimated. Acceleration responses of a historic building and a residential home are presented for flyover noise from subsonic and supersonic aircraft. Possible effects on occupant comfort are assessed. The results from these three examples show that aircraft noise can induce structural responses that are large enough to require consideration in the design or operation of the aircraft.

  4. Proteus aircraft over Las Cruces International Airport in New Mexico.

    Science.gov (United States)

    2002-01-01

    The unique Proteus aircraft served as a test bed for NASA-sponsored flight tests designed to validate collision-avoidance technologies proposed for uninhabited aircraft. The tests, flown over southern New Mexico in March, 2002, used the Proteus as a surrogate uninhabited aerial vehicle (UAV) while three other aircraft flew toward the Proteus from various angles on simulated collision courses. Radio-based 'detect, see and avoid' equipment on the Proteus successfully detected the other aircraft and relayed that information to a remote pilot on the ground at Las Cruces Airport. The pilot then transmitted commands to the Proteus to maneuver it away from the potential collisions. The flight demonstration, sponsored by NASA Dryden Flight Research Center, New Mexico State University, Scaled Composites, the U.S. Navy and Modern Technology Solutions, Inc., were intended to demonstrate that UAVs can be flown safely and compatibly in the same skies as piloted aircraft.

  5. Proteus aircraft low-level flyby at Las Cruces Airport.

    Science.gov (United States)

    2002-01-01

    The unique Proteus aircraft served as a test bed for NASA-sponsored flight tests designed to validate collision-avoidance technologies proposed for uninhabited aircraft. The tests, flown over southern New Mexico in March, 2002, used the Proteus as a surrogate uninhabited aerial vehicle (UAV) while three other aircraft flew toward the Proteus from various angles on simulated collision courses. Radio-based 'detect, see and avoid' equipment on the Proteus successfully detected the other aircraft and relayed that information to a remote pilot on the ground at Las Cruces Airport. The pilot then transmitted commands to the Proteus to maneuver it away from the potential collisions. The flight demonstration, sponsored by NASA Dryden Flight Research Center, New Mexico State University, Scaled Composites, the U.S. Navy and Modern Technology Solutions, Inc., were intended to demonstrate that UAVs can be flown safely and compatibly in the same skies as piloted aircraft.

  6. Multispectral imaging of aircraft exhaust

    Science.gov (United States)

    Berkson, Emily E.; Messinger, David W.

    2016-05-01

    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.

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

    Data.gov (United States)

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

  8. 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

    Science.gov (United States)

    Gerren, Donna S.

    1995-01-01

    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.

  9. The research of optical windows used in aircraft sensor systems

    International Nuclear Information System (INIS)

    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 flat 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. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  10. Aircraft-skin Infrared Radiation Characteristics Modeling and Analysis

    Institute of Scientific and Technical Information of China (English)

    Lu Jianwei; Wang Qiang

    2009-01-01

    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.

  11. Obstacle avoidance and path planning for carrier aircraft launching

    Directory of Open Access Journals (Sweden)

    Wu Yu

    2015-06-01

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

  12. ERAST Program Proteus Aircraft in Flight

    Science.gov (United States)

    1999-01-01

    The unusual design of the Proteus high-altitude aircraft, incorporating a gull-wing shape for its main wing and a long, slender forward canard, is clearly visible in this view of the aircraft in flight over the Mojave Desert in California. In the Proteus Project, NASA's Dryden Flight Research Center, Edwards, California, is assisting Scaled Composites, Inc., Mojave, California, in developing a sophisticated station-keeping autopilot system and a Satellite Communications (SATCOM)-based uplink-downlink data system for aircraft and payload data under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) project. The ERAST Project is sponsored by the Office of Aero-Space Technology at NASA Headquarters, and is managed by the Dryden Flight Research Center. The Proteus is a unique aircraft, designed as a high-altitude, long-duration telecommunications relay platform with potential for use on atmospheric sampling and Earth-monitoring science missions. The aircraft is designed to be flown by two pilots in a pressurized cabin, but also has the potential to perform its missions semiautonomously or be flown remotely from the ground. Flight testing of the Proteus, beginning in the summer of 1998 at Mojave Airport through the end of 1999, included the installation and checkout of the autopilot system, including the refinement of the altitude hold and altitude change software. The SATCOM equipment, including avionics and antenna systems, had been installed and checked out in several flight tests. The systems performed flawlessly during the Proteus's deployment to the Paris Airshow in 1999. NASA's ERAST project funded development of an Airborne Real-Time Imaging System (ARTIS). Developed by HyperSpectral Sciences, Inc., the small ARTIS camera was demonstrated during the summer of 1999 when it took visual and near-infrared photos over the Experimental Aircraft Association's 'AirVenture 99' Airshow at Oshkosh, Wisconsin. The images were displayed on a computer

  13. Coordination control of quadrotor VTOL aircraft in three-dimensional space

    Science.gov (United States)

    Do, K. D.

    2015-03-01

    This paper presents a constructive design of distributed coordination controllers for a group of N quadrotor vertical take-off and landing (VTOL) aircraft in three-dimensional space. A combination of Euler angles and unit-quaternion for the attitude representation of the aircraft is used to result in an effective control design, and to reduce singularities in the aircraft's dynamics. The coordination control design is based on a new bounded control design technique for second-order systems and new pairwise collision avoidance functions. The pairwise collision functions are functions of both relative positions and relative velocities between the aircraft instead of only their relative positions as in the literature. To overcome the inherent underactuation of the aircraft, the roll and pitch angles of the aircraft are considered as immediate controls. Simulations illustrate the results.

  14. AEROSTATIC AND AERODYNAMIC MODULES OF A HYBRID BUOYANT AIRCRAFT: AN ANALYTICAL APPROACH

    Directory of Open Access Journals (Sweden)

    Anwar Ul Haque

    2015-05-01

    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.

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

    Science.gov (United States)

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

    1981-01-01

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

  16. NASA's Aeroacoustic Tools and Methods for Analysis of Aircraft Noise

    Science.gov (United States)

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

    2015-01-01

    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

  17. Small Aircraft Transportation System, Higher Volume Operations Concept: Normal Operations

    Science.gov (United States)

    Abbott, Terence S.; Jones, Kenneth M.; Consiglio, Maria C.; Williams, Daniel M.; Adams, Catherine A.

    2004-01-01

    This document defines the Small Aircraft Transportation System (SATS), Higher Volume Operations (HVO) concept for normal conditions. In this concept, a block of airspace would be established around designated non-towered, non-radar airports during periods of poor weather. Within this new airspace, pilots would take responsibility for separation assurance between their aircraft and other similarly equipped aircraft. Using onboard equipment and procedures, they would then approach and land at the airport. Departures would be handled in a similar fashion. The details for this operational concept are provided in this document.

  18. Application of nonlinear feedback control theory to supermaneuverable aircraft

    Science.gov (United States)

    Garrard, William L.; Enns, Dale F.

    1991-01-01

    Controlled flight at extremely high angles of attack, far exceeding the stall angle, and/or at high angular rates is sometimes referred to as supermaneuvering flight. The objective was to examine methods for design of control laws for aircraft performing supermaneuvers. Since the equations which govern the motion of aircraft during supermaneuvers are nonlinear, this study concentrated on nonlinear control law design procedures. The two nonlinear techniques considered were Nonlinear Quadratic Regulator (NLQR) theory and nonlinear dynamic inversion. A conventional gain scheduled proportional plus integral (P + I) controller was also developed to serve as a baseline design typical of current control laws used in aircraft. A mathematical model of a generic supermaneuverable aircraft was developed from data obtained from the literature. A detailed computer simulation of the aircraft was also developed. This simulation allowed the flying of proposed supermaneuvers and was used to evaluate the performance of the control law designs and to generate linearized models of the aircraft at different flight conditions.

  19. 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)

    张洁

    2015-01-01

    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.

  20. 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)

    张洁

    2015-01-01

    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.%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.

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

    Science.gov (United States)

    Brown, Gerald V.; Kascak, Albert F.

    2004-01-01

    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.

  2. The passive and active noise control strategy in the aircraft interior noise

    OpenAIRE

    Paonessa, A.

    1994-01-01

    The stringent comfort requirements that the airliners are providing to the aircraft manufacturers, also for the small regional commuter are increasing the attention of the aircraft designer to the aircraft interior noise performance. The research on the design methodologies is very much improved in the last years providing new materials and new system like the active noise control usefull to get a more comfortable interior and achieve a large competition on the market. In this paper a general...

  3. Frequency Analysis of Aircraft hazards for License Application

    International Nuclear Information System (INIS)

    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

  4. Tactical aircraft optical cable plant program plan

    Science.gov (United States)

    Weaver, Thomas L.; Murdock, John K.; Ide, James R.

    1995-05-01

    A program was created with joint industry and government funding to apply fiber optic technologies to tactical aircraft. The technology offers many potential benefits, including increased electromagnetic interference immunity and the possibility of reduced weight, increased reliability, and enlarged capability from redesigning architectures to use the large bandwidth of fiber optics. Those benefits will only be realized if fiber optics meets the unique requirements of aircraft networks. The application of fiber optics to tactical aircraft presents challenges to physical components which can only be met by a methodical attention to what is required, what are the conditions of use, and how will the components be produced in the broad context of a fiber optics using economy. For this purpose, the FLASH program has outlined a plan, and developed a team to evaluate requirements, delineate environmental and use conditions, and design practical, low cost components for tactical aircraft fiber optic cable plants including cables, connectors, splices, backplanes, manufacturing and installation methods, and test and maintenance methods.

  5. Towards Intelligent Control for Next Generation Aircraft

    Science.gov (United States)

    Acosta, Diana Michelle; KrishnaKumar, Kalmanje Srinvas; Frost, Susan Alane

    2008-01-01

    NASA Aeronautics Subsonic Fixed Wing Project is focused on mitigating the environmental and operation impacts expected as aviation operations triple by 2025. The approach is to extend technological capabilities and explore novel civil transport configurations that reduce noise, emissions, fuel consumption and field length. Two Next Generation (NextGen) aircraft have been identified to meet the Subsonic Fixed Wing Project goals - these are the Hybrid Wing-Body (HWB) and Cruise Efficient Short Take-Off and Landing (CESTOL) aircraft. The technologies and concepts developed for these aircraft complicate the vehicle s design and operation. In this paper, flight control challenges for NextGen aircraft are described. The objective of this paper is to examine the potential of state-of-the-art control architectures and algorithms to meet the challenges and needed performance metrics for NextGen flight control. A broad range of conventional and intelligent control approaches are considered, including dynamic inversion control, integrated flight-propulsion control, control allocation, adaptive dynamic inversion control, data-based predictive control and reinforcement learning control.

  6. Control of a swept wing tailless aircraft through wing morphing

    Science.gov (United States)

    Guiler, Richard W.

    Inspired by flight in nature, work done by Lippisch, the Hortens, and Northrop offered insight to achieving the efficiency of bird flight with swept-wing tailless aircraft. Tailless designs must incorporate aerodynamic compromises for control, which have inhibited potential advantages. A morphing mechanism, capable of changing the twist of wing and that can also provide pitch, roll and yaw control for a tailless swept wing aircraft is the first step to a series of morphing techniques, which will lead to more fluid, bird-like flight. This research focuses on investigating the design of a morphing wing to improve the flight characteristics of swept wing Horten type tailless aircraft. Free flight demonstrators, wind tunnel flow visualization, wind-tunnel force and moment data along with CFD studies have been used to evaluate the stability, control and efficiency of a morphing swept wing tailless aircraft. A wing morphing mechanism for the control of a swept wing tailless aircraft has been developed. This new control technique was experimentally and numerically compared to an existing elevon equipped tailless aircraft and has shown the potential for significant improvement in efficiency. The feasibility of this mechanism was also validated through flight testing of a flight weight version. In the process of comparing the Horten type elevon equipped aircraft and the morphing model, formal wind tunnel verification of wingtip induced thrust, found in Horten (Bell Shaped Lift distribution) type swept wing tailless aircraft was documented. A more complete physical understanding of the highly complex flow generated in the control region of the morphing tailless aircraft has been developed. CFD models indicate the possibility of the presence of a Leading Edge Vortex (LEV) on the control section morphing wing when the tip is twisted between +3.5 degrees and +7 degrees. The presence of this LEV causes a reduction of drag while lift is increased. Similar LEVs have been

  7. Route optimization model for strike aircraft

    OpenAIRE

    Lee, Steve H. K.

    1995-01-01

    A model is designed and implemented to construct a 'flyable,' least- risk route for strike aircraft from takeoff to target, through enemy radars, in a defined area of operations. A network is fust constructed by discretizing the airspace into a three-dimensional grid of nodes and then connecting adjacent nodes with arcs. A shortest-path model in this network is then constructed with arc lengths that are a function of the probability of detection by radars monitoring t...

  8. Trajectory management for aircraft noise mitigation

    OpenAIRE

    Prats Menéndez, Xavier; Quevedo Casín, Joseba Jokin; Puig Cayuela, Vicenç

    2009-01-01

    Comunicació convidada This paper gives an overview of aircraft trajectory management aimed at producing noise abatementprocedures. Area Navigation (RNAV) concepts play an important role in the design of flexible and, therefore, noise friendly depart or approach procedures. In addition, the lowest dispersion of RNAV tracks help to contain noise footprints in a smaller area if compared with footprints that are produced when conventional procedures are flown. However, RNAV turns still produce...

  9. Active Noise Control in Propeller Aircraft

    OpenAIRE

    Johansson, Sven; Claesson, Ingvar

    2001-01-01

    A noisy environment dominated by low frequency noise can often be improved through the use of active noise control. This situation arises naturally in propeller aircraft where the propellers induce periodic low frequency noise inside the cabin. The cabin noise is typically rather high, and the passenger flight comfort could be improved considerably if this level were significantly reduced. This paper addresses same design aspects for multiple-reference active noise control systems based on th...

  10. Aircraft Vehicle Systems Modeling and Simulation under Uncertainty

    OpenAIRE

    Steinkellner, Sören

    2011-01-01

    In aircraft development, it is crucial to understand and evaluate behavior, performance, safety and other aspects of the systems before and after they are physically available for testing. Simulation models are used to gain knowledge in order to make decisions at all development stages. Modeling and simulation (M&S) in aircraft system development, for example of fuel, hydraulic and electrical power systems, is today an important part of the design process. Through M&S a problem in a f...

  11. Cabin environment and air quality in civil transport aircraft

    OpenAIRE

    Zhou, Weiguo

    2012-01-01

    The cabin environment of a commercial aircraft, including cabin layout and the quality of air supply, is crucial to the airline operators. These aspects directly affect the passengers’ experience and willing to travel. This aim of this thesis is to design the cabin layout for flying wing aircraft as part of cabin environment work, followed by the air quality work, which is to understand what effect the ECS can have in terms of cabin air contamination. The project, initially, focuses on the...

  12. AASPT Carbon/Carbon Aircraft Brake Disk Granted MPA

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    @@ 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.

  13. 19 CFR 122.64 - Other aircraft.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Other aircraft. 122.64 Section 122.64 Customs... AIR COMMERCE REGULATIONS Clearance of Aircraft and Permission To Depart § 122.64 Other aircraft. Clearance or permission to depart shall be requested by the aircraft commander or agent for aircraft...

  14. 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.;

    1995-01-01

    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....

  15. Dynamic of SDOF elastic-plastic system subjected to aircraft impact pulses

    International Nuclear Information System (INIS)

    In this paper the responses of elastic-plastic SDOF systems subjected to aircraft impact pulses are calculated. The results are compared with simpler pulse models and represented in the useful form of design charts. Two well-known approaches to seismic spectra are examined for the design of aircraft impact spectra. (orig.)

  16. Chemistry in aircraft plumes

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-12-31

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

  17. Aircraft Inspection for the General Aviation Aircraft Owner.

    Science.gov (United States)

    Federal Aviation Administration (DOT), Washington, DC. Flight Standards Service.

    Presented is useful information for owners, pilots, student mechanics, and others with aviation interests. Part I of this booklet outlines aircraft inspection requirements, owner responsibilities, inspection time intervals, and sources of basic information. Part II is concerned with the general techniques used to inspect an aircraft. (Author/JN)

  18. Trust Control of VTOL Aircraft Part Deux

    Science.gov (United States)

    Dugan, Daniel C.

    2014-01-01

    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. Analysis of Aircraft Control Performance using a Fuzzy Rule Base Representation of the Cooper-Harper Aircraft Handling Quality Rating

    Science.gov (United States)

    Tseng, Chris; Gupta, Pramod; Schumann, Johann

    2006-01-01

    The Cooper-Harper rating of Aircraft Handling Qualities has been adopted as a standard for measuring the performance of aircraft since it was introduced in 1966. Aircraft performance, ability to control the aircraft, and the degree of pilot compensation needed are three major key factors used in deciding the aircraft handling qualities in the Cooper- Harper rating. We formulate the Cooper-Harper rating scheme as a fuzzy rule-based system and use it to analyze the effectiveness of the aircraft controller. The automatic estimate of the system-level handling quality provides valuable up-to-date information for diagnostics and vehicle health management. Analyzing the performance of a controller requires a set of concise design requirements and performance criteria. Ir, the case of control systems fm a piloted aircraft, generally applicable quantitative design criteria are difficult to obtain. The reason for this is that the ultimate evaluation of a human-operated control system is necessarily subjective and, with aircraft, the pilot evaluates the aircraft in different ways depending on the type of the aircraft and the phase of flight. In most aerospace applications (e.g., for flight control systems), performance assessment is carried out in terms of handling qualities. Handling qualities may be defined as those dynamic and static properties of a vehicle that permit the pilot to fully exploit its performance in a variety of missions and roles. Traditionally, handling quality is measured using the Cooper-Harper rating and done subjectively by the human pilot. In this work, we have formulated the rules of the Cooper-Harper rating scheme as fuzzy rules with performance, control, and compensation as the antecedents, and pilot rating as the consequent. Appropriate direct measurements on the controller are related to the fuzzy Cooper-Harper rating system: a stability measurement like the rate of change of the cost function can be used as an indicator if the aircraft is under

  20. Aviation industry-research in aircraft finance

    OpenAIRE

    Ehrenthal, Joachim C.F.

    2010-01-01

    Aircraft values are key to aircraft financing decisions: Aircraft values act as a source of security for providers of debt capital and lessors failing to re-place aircraft, and as a source of upside potential to equity investors. Yet, aircraft values cannot be precisely and continuously monitored. This is because neither actual primary nor secondary aircraft transaction prices are disclosed. Various types of third party valuation estimates exist, but relying solely on third party appraisa...

  1. Probabilistic Modeling of Aircraft Trajectories for Dynamic Separation Volumes

    Science.gov (United States)

    Lewis, Timothy A.

    2016-01-01

    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.

  2. MISSILES AND AIRCRAFT (PART1

    Directory of Open Access Journals (Sweden)

    C.M. Meyer

    2012-02-01

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

  3. Intelligent control of agile aircraft

    Energy Technology Data Exchange (ETDEWEB)

    Mohler, R.R.; Zakrzewski, R.R. [Dept. of Electrical and Computer Engineering, Corvallis, OR (United States)

    1994-12-31

    A brief overview of adaptive and computer-aided flight control is presented as background for the evolution of recent research on nonlinear intelligent control. Here, several nonlinear control algorithms are investigated but emphasis is given to nearly time-optimal, neural-net generated feedback control which is trained on ideal minimum-time, open-loop trajectories. The minimum-time policies are computed by a new version of the switching-line-variational method (gradient algorithm). Critical control constraints and a benchmark for performance as well as a basis for training are obtained for the system design. This further demonstrates the need for an integrated controls and aircraft system design for full utilization of nonlinear control capability. Complex nonlinear simulations show the effectiveness of the derived nonlinear feedback controller for the high-angle-of-attack research vehicle (HARV) with stabilator and thrust-vector control. For example, angle of attack is controlled from near zero to sixty degrees in about two seconds with appropriate trim conditions at both ends. Such control greatly enhances maneuverability and general flight envelope admissibility.

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

    International Nuclear Information System (INIS)

    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).

  5. Squeeze Film Damping for Aircraft Gas Turbines

    Directory of Open Access Journals (Sweden)

    R. W. Shende

    1988-10-01

    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.

  6. A practical scheme for adaptive aircraft flight control systems

    Science.gov (United States)

    Athans, M.; Willner, D.

    1974-01-01

    A flight control system design is presented, that can be implemented by analog hardware, to be used to control an aircraft with uncertain parameters. The design is based upon the use of modern control theory. The ideas are illustrated by considering control of STOL longitudinal dynamics.

  7. DEVELOPMENT OF EDUCATIONAL SOFTWARE FOR STRESS ANALYSIS OF AN AIRCRAFT WING

    Directory of Open Access Journals (Sweden)

    TAZKERA SADEQ

    2012-06-01

    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.

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

    Science.gov (United States)

    Monaghan, Kari L.

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

  9. System Design for Transitional Aircraft Support

    Directory of Open Access Journals (Sweden)

    John P.T. Mo

    2014-01-01

    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.

  10. Commercial aircraft composite technology

    CERN Document Server

    Breuer, Ulf Paul

    2016-01-01

    This book is based on lectures held at the faculty of mechanical engineering at the Technical University of Kaiserslautern. The focus is on the central theme of societies overall aircraft requirements to specific material requirements and highlights the most important advantages and challenges of carbon fiber reinforced plastics (CFRP) compared to conventional materials. As it is fundamental to decide on the right material at the right place early on the main activities and milestones of the development and certification process and the systematic of defining clear requirements are discussed. The process of material qualification - verifying material requirements is explained in detail. All state-of-the-art composite manufacturing technologies are described, including changes and complemented by examples, and their improvement potential for future applications is discussed. Tangible case studies of high lift and wing structures emphasize the specific advantages and challenges of composite technology. Finally,...

  11. Aircraft recognition and pose estimation

    Science.gov (United States)

    Hmam, Hatem; Kim, Jijoong

    2000-05-01

    This work presents a geometry based vision system for aircraft recognition and pose estimation using single images. Pose estimation improves the tracking performance of guided weapons with imaging seekers, and is useful in estimating target manoeuvres and aim-point selection required in the terminal phase of missile engagements. After edge detection and straight-line extraction, a hierarchy of geometric reasoning algorithms is applied to form line clusters (or groupings) for image interpretation. Assuming a scaled orthographic projection and coplanar wings, lateral symmetry inherent in the airframe provides additional constraints to further reject spurious line clusters. Clusters that accidentally pass all previous tests are checked against the original image and are discarded. Valid line clusters are then used to deduce aircraft viewing angles. By observing that the leading edges of wings of a number of aircraft of interest are within 45 to 65 degrees from the symmetry axis, a bounded range of aircraft viewing angles can be found. This generic property offers the advantage of not requiring the storage of complete aircraft models viewed from all aspects, and can handle aircraft with flexible wings (e.g. F111). Several aircraft images associated with various spectral bands (i.e. visible and infra-red) are finally used to evaluate the system's performance.

  12. High altitude aircraft flight tests

    Science.gov (United States)

    Helmken, Henry; Emmons, Peter; Homeyer, David

    1996-03-01

    In order to make low earth orbit L-band propagation measurements and test new voice communication concepts, a payload was proposed and accepted for flight aboard the COMET (now METEOR) spacecraft. This Low Earth Orbiting EXperiment payload (LEOEX) was designed and developed by Motorola Inc. and sponsored by the Space Communications Technology Center (SCTC), a NASA Center for the Commercial Development of Space (CCDS) located at Florida Atlantic University. In order to verify the LEOEX payload for satellite operation and obtain some preliminary propagation data, a series of 9 high altitude aircraft (SR-71 and ER-2) flight tests were conducted. These flights took place during a period of 7 months, from October 1993 to April 1994. This paper will summarize the operation of the LEOEX payload and the particular configuration used for these flights. The series of flyby tests were very successful and demonstrated how bi-directional, Time Division Multiple Access (TDMA) voice communication will work in space-to-ground L-band channels. The flight tests also acquired propagation data which will be representative of L-band Low Earth Orbiting (LEO) communication systems. In addition to verifying the LEOEX system operation, it also uncovered and ultimately aided the resolution of several key technical issues associated with the payload.

  13. Active Structural Control for Aircraft Efficiency with the X-56A Aircraft

    Science.gov (United States)

    Ouellette, Jeffrey

    2015-01-01

    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.

  14. Assessment of sensors and aircraft for oil spill remote sensing

    International Nuclear Information System (INIS)

    Environment Canada has assessed sensors and aircraft suitable for remote sensing, particularly the capability of sensors to detect oil and to discriminate oil from background targets. The assessment was based on past experience and technical considerations. The first sensor recommended for use is an infrared camera or an IR/UV system. This recommendation is based on the system's ability to detect oil and discriminate this from the background, and the low cost of these sensors. The laser fluorosensor is recommended as the second device, as it is the only unit capable of positively discriminating oil on water, among weeds, and in sediment or beach material. Cameras operating in the visible region of the spectrum are recommended for two functions: documentation and providing background or location imagery for other sensors. Imaging radars, be they SAR or SLAR, are recommended for long-range searches or for oil spill work at night or when fog is present. Radars are expensive and require dedicated aircraft. Passive microwave devices are currently being developed but have not been proven as an alternative to radar or for measuring slick thickness. A laser based thickness sensor is under development. Satellite systems were also assessed. Satellite sensors operating in the visible spectrum have only limited application to major oil spills. New radar sensors show limited potential. The major limitation of any satellite system is the limited coverage time that is a function of its orbit. A study of aircraft and aircraft modifications was carried out to catalog aircraft modifications necessary to operate oil spill remote sensors. A potential user could select modifications that are already approved and thus save the high costs of aircraft modification design. The modifications already approved in Canada and the US for a given aircraft provide criteria for the selection of an aircraft

  15. 36 CFR 331.14 - Aircraft.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Aircraft. 331.14 Section 331..., KENTUCKY AND INDIANA § 331.14 Aircraft. (a) The operation of aircraft on WCA lands and waters is prohibited... prohibited. (c) The provisions of this section shall not be applicable to aircraft engaged on...

  16. 48 CFR 246.408-71 - Aircraft.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Aircraft. 246.408-71... Aircraft. (a) The Federal Aviation Administration (FAA) has certain responsibilities and prerogatives in connection with some commercial aircraft and of aircraft equipment and accessories (Pub. L. 85-726 (72...

  17. 36 CFR 327.4 - Aircraft.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Aircraft. 327.4 Section 327.4... Aircraft. (a) This section pertains to all aircraft including, but not limited to, airplanes, seaplanes, helicopters, ultra-light aircraft, motorized hang gliders, hot air balloons, any non-powered flight devices...

  18. 14 CFR 141.39 - Aircraft.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Aircraft. 141.39 Section 141.39 Aeronautics... CERTIFICATED AGENCIES PILOT SCHOOLS Personnel, Aircraft, and Facilities Requirements § 141.39 Aircraft. (a... certificate or provisional pilot school certificate must show that each aircraft used by the school for...

  19. 40 CFR 87.6 - Aircraft safety.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Aircraft safety. 87.6 Section 87.6... POLLUTION FROM AIRCRAFT AND AIRCRAFT ENGINES General Provisions § 87.6 Aircraft safety. The provisions of... met within the specified time without creating a safety hazard....

  20. A NASA study of the impact of technology on future carrier based tactical aircraft - Overview

    Science.gov (United States)

    Wilson, S. B., III

    1992-01-01

    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.

  1. Global Tracking Control of Quadrotor VTOL Aircraft in Three-Dimensional Space

    Directory of Open Access Journals (Sweden)

    Duc Khac Do

    2014-07-01

    Full Text Available This paper presents a method to design controllers that force a quadrotor vertical take-off and landing (VTOL aircraft to globally asymptotically track a reference trajectory in three-dimensional space. Motivated by the vehicle's steering practice, the roll and pitch angles are considered as immediate controls plus the total thrust force  provided by the aircraft's four rotors to control the position and yaw angle of the aircraft. The control design is based on the newly introduced one-step ahead backstepping, the standard backstepping and Lyapunov's direct methods. A combination of Euler angles and unit-quaternion for the attitude representation of the aircraft is used to obtain global tracking control results. The paper also includes a design of observers that exponentially estimate the aircraft's linear velocity vector and disturbances. Simulations illustrate the results.

  2. System level airworthiness tool: A comprehensive approach to small unmanned aircraft system airworthiness

    Science.gov (United States)

    Burke, David A.

    One of the pillars of aviation safety is assuring sound engineering practices through airworthiness certification. As Unmanned Aircraft Systems (UAS) grow in popularity, the need for airworthiness standards and verification methods tailored for UAS becomes critical. While airworthiness practices for large UAS may be similar to manned aircraft, it is clear that small UAS require a paradigm shift from the airworthiness practices of manned aircraft. Although small in comparison to manned aircraft these aircraft are not merely remote controlled toys. Small UAS may be complex aircraft flying in the National Airspace System (NAS) over populated areas for extended durations and beyond line of sight of the operators. A comprehensive systems engineering framework for certifying small UAS at the system level is needed. This work presents a point based tool that evaluates small UAS by rewarding good engineering practices in design, analysis, and testing. The airworthiness requirements scale with vehicle size and operational area, while allowing flexibility for new technologies and unique configurations.

  3. Western Pacific Typhoon Aircraft Fixes

    Data.gov (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...

  4. Electromagnetic Interference In New Aircraft

    Science.gov (United States)

    Larsen, William E.

    1991-01-01

    Report reviews plans to develop tests and standards to ensure that digital avionics systems in new civil aircraft immune to electromagnetic interference (EMI). Updated standards reflect more severe environment and vulnerabilities of modern avionics.

  5. VTOL to Transonic Aircraft Project

    Data.gov (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...

  6. Mission Analysis and Aircraft Sizing of a Hybrid-Electric Regional Aircraft

    Science.gov (United States)

    Antcliff, Kevin R.; Guynn, Mark D.; Marien, Ty V.; Wells, Douglas P.; Schneider, Steven J.; Tong, Michael T.

    2016-01-01

    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.

  7. Users Guide for NASA Lewis Research Center DC-9 Reduced-Gravity Aircraft Program

    Science.gov (United States)

    Neumann, Eric S.; Withrow, James P.; Yaniec, John S.

    1996-01-01

    The document provides guidelines and information for users of the DC-9 Reduced-Gravity Aircraft Program. It describes the facilities, requirements for test personnel, equipment design and installation, mission preparation, and in-flight procedures. Those who have used the KC-135 reduced-gravity aircraft will recognize that many of the procedures and guidelines are the same.

  8. Evaluation of active control technology for short haul aircraft. [cost effectiveness

    Science.gov (United States)

    Renshaw, J. H.; Bennett, J. A.; Harris, O. C.; Honrath, J. F.; Patterson, R. W.

    1975-01-01

    An evaluation of the economics of short-haul aircraft designed with active controls technology and low wing-loading to achieve short field performance with good ride quality is presented. Results indicate that for such a system incorporating gust load alleviation and augmented stability the direct operating cost is better than for aircraft without active controls.

  9. Challenges in Aircraft Noise Prediction

    OpenAIRE

    Filippone A

    2014-01-01

    This contribution addresses the problem of aircraft noise prediction using theoretical methods. The problem is set in context with the needs at several levels to produce noise characterisation from commercial aircraft powered by gas turbine engines. We describe very briefly the computational model (whilst referring the reader to the appropriate literature), and provide examples of noise predictions and comparisons with measured data, where possible. We focus on the issue of stochastic analysi...

  10. Neural networks for aircraft control

    Science.gov (United States)

    Linse, Dennis

    1990-01-01

    Current research in Artificial Neural Networks indicates that networks offer some potential advantages in adaptation and fault tolerance. This research is directed at determining the possible applicability of neural networks to aircraft control. The first application will be to aircraft trim. Neural network node characteristics, network topology and operation, neural network learning and example histories using neighboring optimal control with a neural net are discussed.

  11. 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)

    1997-12-31

    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.

  12. Optimization in fractional aircraft ownership

    Science.gov (United States)

    Septiani, R. D.; Pasaribu, H. M.; Soewono, E.; Fayalita, R. A.

    2012-05-01

    Fractional Aircraft Ownership is a new concept in flight ownership management system where each individual or corporation may own a fraction of an aircraft. In this system, the owners have privilege to schedule their flight according to their needs. Fractional management companies (FMC) manages all aspects of aircraft operations, including utilization of FMC's aircraft in combination of outsourced aircrafts. This gives the owners the right to enjoy the benefits of private aviations. However, FMC may have complicated business requirements that neither commercial airlines nor charter airlines faces. Here, optimization models are constructed to minimize the number of aircrafts in order to maximize the profit and to minimize the daily operating cost. In this paper, three kinds of demand scenarios are made to represent different flight operations from different types of fractional owners. The problems are formulated as an optimization of profit and a daily operational cost to find the optimum flight assignments satisfying the weekly and daily demand respectively from the owners. Numerical results are obtained by Genetic Algorithm method.

  13. Swarms of UAVs and fighter aircraft

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-11-01

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

  14. 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)

    NONE

    2001-07-01

    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.)

  15. Silent Aircraft Initiative Concept Risk Assessment

    Science.gov (United States)

    Nickol, Craig L.

    2008-01-01

    A risk assessment of the Silent Aircraft Initiative's SAX-40 concept design for extremely low noise has been performed. A NASA team developed a list of 27 risk items, and evaluated the level of risk for each item in terms of the likelihood that the risk would occur and the consequences of the occurrence. The following risk items were identified as high risk, meaning that the combination of likelihood and consequence put them into the top one-fourth of the risk matrix: structures and weight prediction; boundary-layer ingestion (BLI) and inlet design; variable-area exhaust and thrust vectoring; displaced-threshold and continuous descent approach (CDA) operational concepts; cost; human factors; and overall noise performance. Several advanced-technology baseline concepts were created to serve as a basis for comparison to the SAX-40 concept. These comparisons indicate that the SAX-40 would have significantly greater research, development, test, and engineering (RDT&E) and production costs than a conventional aircraft with similar technology levels. Therefore, the cost of obtaining the extremely low noise capability that has been estimated for the SAX-40 is significant. The SAX-40 concept design proved successful in focusing attention toward low noise technologies and in raising public awareness of the issue.

  16. Aircraft hydraulic power system diagnostic, prognostics and health management

    OpenAIRE

    Wang, Jian

    2012-01-01

    This Individual Research Project (IRP) is the extension research to the group design project (GDP) work which the author has participated in his Msc programme. The GDP objective is to complete the conceptual design of a 200-seat, flying wing civil airliner—FW-11. The next generation aircraft design demands higher reliability, safety and maintainability. With the development of the vehicle hydraulic system technology, the equipment and systems become more and more complex, their reliability...

  17. Current and Future Research in Active Control of Lightweight, Flexible Structures Using the X-56 Aircraft

    Science.gov (United States)

    Ryan, John J.; Bosworth, John T.; Burken, John J.; Suh, Peter M.

    2014-01-01

    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.

  18. 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

    2013-01-01

    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.

  19. Fracture control procedures for aircraft structural integrity

    Science.gov (United States)

    Wood, H. A.

    1972-01-01

    The application of applied fracture mechanics in the design, analysis, and qualification of aircraft structural systems are reviewed. Recent service experiences are cited. Current trends in high-strength materials application are reviewed with particular emphasis on the manner in which fracture toughness and structural efficiency may affect the material selection process. General fracture control procedures are reviewed in depth with specific reference to the impact of inspectability, structural arrangement, and material on proposed analysis requirements for safe crack growth. The relative impact on allowable design stress is indicated by example. Design criteria, material, and analysis requirements for implementation of fracture control procedures are reviewed together with limitations in current available data techniques. A summary of items which require further study and attention is presented.

  20. Aircraft Cabin Environmental Quality Sensors

    Energy Technology Data Exchange (ETDEWEB)

    Gundel, Lara; Kirchstetter, Thomas; Spears, Michael; Sullivan, Douglas

    2010-05-06

    The Indoor Environment Department at Lawrence Berkeley National Laboratory (LBNL) teamed with seven universities to participate in a Federal Aviation Administration (FAA) Center of Excellence (COE) for research on environmental quality in aircraft. This report describes research performed at LBNL on selecting and evaluating sensors for monitoring environmental quality in aircraft cabins, as part of Project 7 of the FAA's COE for Airliner Cabin Environmental Research (ACER)1 effort. This part of Project 7 links to the ozone, pesticide, and incident projects for data collection and monitoring and is a component of a broader research effort on sensors by ACER. Results from UCB and LBNL's concurrent research on ozone (ACER Project 1) are found in Weschler et al., 2007; Bhangar et al. 2008; Coleman et al., 2008 and Strom-Tejsen et al., 2008. LBNL's research on pesticides (ACER Project 2) in airliner cabins is described in Maddalena and McKone (2008). This report focused on the sensors needed for normal contaminants and conditions in aircraft. The results are intended to complement and coordinate with results from other ACER members who concentrated primarily on (a) sensors for chemical and biological pollutants that might be released intentionally in aircraft; (b) integration of sensor systems; and (c) optimal location of sensors within aircraft. The parameters and sensors were selected primarily to satisfy routine monitoring needs for contaminants and conditions that commonly occur in aircraft. However, such sensor systems can also be incorporated into research programs on environmental quality in aircraft cabins.

  1. Flying Unmanned Aircraft: A Pilot's Perspective

    Science.gov (United States)

    Pestana, Mark E.

    2011-01-01

    The National Aeronautics and Space Administration (NASA) is pioneering various Unmanned Aircraft System (UAS) technologies and procedures which may enable routine access to the National Airspace System (NAS), with an aim for Next Gen NAS. These tools will aid in the development of technologies and integrated capabilities that will enable high value missions for science, security, and defense, and open the door to low-cost, extreme-duration, stratospheric flight. A century of aviation evolution has resulted in accepted standards and best practices in the design of human-machine interfaces, the displays and controls of which serve to optimize safe and efficient flight operations and situational awareness. The current proliferation of non-standard, aircraft-specific flight crew interfaces in UAS, coupled with the inherent limitations of operating UAS without in-situ sensory input and feedback (aural, visual, and vestibular cues), has increased the risk of mishaps associated with the design of the "cockpit." The examples of current non- or sub- standard design features range from "annoying" and "inefficient", to those that are difficult to manipulate or interpret in a timely manner, as well as to those that are "burdensome" and "unsafe." A concerted effort is required to establish best practices and standards for the human-machine interfaces, for the pilot as well as the air traffic controller. In addition, roles, responsibilities, knowledge, and skill sets are subject to redefining the terms, "pilot" and "air traffic controller", with respect to operating UAS, especially in the Next-Gen NAS. The knowledge, skill sets, training, and qualification standards for UAS operations must be established, and reflect the aircraft-specific human-machine interfaces and control methods. NASA s recent experiences flying its MQ-9 Ikhana in the NAS for extended duration, has enabled both NASA and the FAA to realize the full potential for UAS, as well as understand the implications of

  2. Frequency Analysis of Aircraft hazards for License Application

    Energy Technology Data Exchange (ETDEWEB)

    K. Ashley

    2006-10-24

    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.

  3. Inlet, engine, airframe controls integration development for supercruising aircraft

    Science.gov (United States)

    Houchard, J. H.; Carlin, C. M.; Tjonneland, E.

    1983-01-01

    In connection with a consideration of advanced military aircraft systems, attention is given to research for improving the technology of the design of supersonic cruise aircraft. Syberg et al. (1981) have shown that an analytic design method is now available to accurately predict the flow characteristics of axisymmetric supersonic inlets, including off-design angle of attack operation. On the basis of information regarding the inlet flow characteristics, the control system designer can begin the inlet design and development, before wind tunnel testing has begun. The present investigation is concerned with details and status of inlet control technology. A detailed representation of a supersonic propulsion system is developed. This development demonstrates the feasibility of the selected hybrid computational concept.

  4. Student team wins NASA's future aircraft undergraduate competition

    OpenAIRE

    Nystrom, Lynn A.

    2008-01-01

    A team of six undergraduate aerospace engineering students from Virginia Tech earned first place honors with their entry of STINGRAE in the 2008 NASA Aircraft Design Competition sponsored by NASA's Aeronautics Research Mission Directorate's Fundamental Aeronautics Program, part of the agency's Aeronautics Research Mission Directorate.

  5. The ahead project: Advanced hybrid engines for aircraft development

    NARCIS (Netherlands)

    Rao, A.G.; Yin, F.

    2013-01-01

    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

  6. Automating wiring formboard design

    NARCIS (Netherlands)

    Van den Berg, T.

    2013-01-01

    Increase in aircraft wiring complexity call for manufacturing design improvements to reduce cost and lead-time. To achieve such improvements, a joint research project was performed by the Flight Performance and Propulsion (FPP) group and Fokker Elmo BV, the second largest aircraft wiring harness man

  7. Analysis of aircraft maintenance models

    Directory of Open Access Journals (Sweden)

    Vlada S. Sokolović

    2011-10-01

    Full Text Available This paper addressed several organizational models of aircraft maintenance. All models presented so far have been in use in Air Forces, so that the advantages and disadvantages of different models are known. First it shows the current model of aircraft maintenance as well as its basic characteristics. Then the paper discusses two organizational models of aircraft maintenance with their advantages and disadvantages. The advantages and disadvantages of different models are analyzed based on the criteria of operational capabilities of military units. In addition to operational capabilities, the paper presents some other criteria which should be taken into account in the evaluation and selection of an optimal model of aircraft maintenance. Performing a qualitative analysis of some models may not be sufficient for evaluating the optimum choice for models of maintenance referring to the selected set of criteria from the scope of operational capabilities. In order to choose the optimum model, it is necessary to conduct a detailed economic and technical analysis of individual tactical model maintenance. A high-quality aircraft maintenance organization requires the highest state and army authorities to be involved. It is necessary to set clear objectives for all the elements of modern air force technical support programs based on the given evaluation criteria.

  8. Aircraft noise footprint for Bucharest – Sophia flights

    OpenAIRE

    Luis MELIVEO; Nico van OOSTEN; Luminita DRAGASANU

    2012-01-01

    Studies of impact noise have traditionally focused on landing and takeoff procedures in the airports vicinity. Beside these studies, en-route noise is considered an issue when we talk about noise in natural reservation or other populated sensitive areas and when it comes to designing a new aircraft engine. In these cases, the studies are focusing on the impact at ground level of the en route noise produced by aircraft at all the flights stages. This paper presents the results of the measureme...

  9. Bayesian Software Health Management for Aircraft Guidance, Navigation, and Control

    Science.gov (United States)

    Schumann, Johann; Mbaya, Timmy; Menghoel, Ole

    2011-01-01

    Modern aircraft, both piloted fly-by-wire commercial aircraft as well as UAVs, more and more depend on highly complex safety critical software systems with many sensors and computer-controlled actuators. Despite careful design and V&V of the software, severe incidents have happened due to malfunctioning software. In this paper, we discuss the use of Bayesian networks (BNs) to monitor the health of the on-board software and sensor system, and to perform advanced on-board diagnostic reasoning. We will focus on the approach to develop reliable and robust health models for the combined software and sensor systems.

  10. Cryocooler for Air Liquefaction Onboard Large Aircraft

    Science.gov (United States)

    Breedlove, J. J.; Magari, P. J.; Miller, G. W.

    2008-03-01

    Creare has developed a turbo-Brayton cryocooler for the Air Force that is designed to produce approximately 1 kW of refrigeration at 95 K. The cryocooler is intended to provide cryogenic cooling for an air separation system being developed to produce and store liquid oxygen and liquid nitrogen onboard large aircraft. The oxygen will be used for high-altitude breathing and medical evacuation operations, while the nitrogen will be used to inert the ullage space inside the fuel tanks. The cryocooler utilizes gas bearings in the turbomachines for long life without maintenance, which is a critical requirement for this application. The mass of a flight version of this cryocooler is expected to be around 270 kg, while the input power is expected to be 21 to 25 kW. This paper describes the design and testing of the technology demonstration cryocooler that was constructed to establish the feasibility of the approach. In the future, the cryocooler will be integrated and tested with a distillation column subsystem. Subsequent testing may also be performed in-flight on an Air Force transport aircraft.

  11. MULTI-CONTROLLER STRUCTURE OF SUPERMANEUVERABLE AIRCRAFT

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    This paper proposes a method of using multi-controllers to control supermaneuverable aircraft. A nonlinear dynamic-inversion controller is used for supermaneuver. A gain-scheduled controller is used for routine maneuver. A switch algorithm is designed to switch the controllers. The flight envelopes of the controllers are different but have a common area in which the controllers are switched from one to the other. In the common area, some special boundaries are selected to decide switch conditions. The controllers all use vector-thrust for lower velocity maneuver control. Unlike the variation-structure theory to use a single boundary, this paper uses two boundaries for switching between the two controllers. One boundary is used for switching from dynamic-inversion to gain-scheduling, while the other is used for switching from gain-scheduling to dynamic-inversion. This can effectively avoid the system vibration caused by switching repeatedly at a single boundary. The method is very easy for engineering. It can reduce the risk of design of the supermaneuverable aircraft.

  12. MATE. Multi Aircraft Training Environment

    DEFF Research Database (Denmark)

    Hauland, G.; Bove, T.; Andersen, Henning Boje;

    2002-01-01

    A medium fidelity and low cost training device for pilots, called the Multi Aircraft Training Environment (MATE), is developed to replace other low fidelity stand-alone training devices and integrate them into a flexible environment, primarily aimed attraining pilots in checklist procedures. The...... cockpit switches and instruments in MATE are computer-generated graphics. The graphics are back projected onto semi-transparent touch screen panels in a hybrid cockpit mock-up. Thus, the MATE is relativelycheap, it is always available, it is reconfigurable (e.g. between types of aircraft/models to be...... in the MATE prototype was compared with the effects of traditional training that included the use of realaircraft. The experimental group (EXP) trained the pre-start checklist and the engine start checklist for the Saab 340 commuter aircraft in a MATE prototype. The control group (CTR) trained the...

  13. Finite-difference modeling of commercial aircraft using TSAR

    Energy Technology Data Exchange (ETDEWEB)

    Pennock, S.T.; Poggio, A.J.

    1994-11-15

    Future aircraft may have systems controlled by fiber optic cables, to reduce susceptibility to electromagnetic interference. However, the digital systems associated with the fiber optic network could still experience upset due to powerful radio stations, radars, and other electromagnetic sources, with potentially serious consequences. We are modeling the electromagnetic behavior of commercial transport aircraft in support of the NASA Fly-by-Light/Power-by-Wire program, using the TSAR finite-difference time-domain code initially developed for the military. By comparing results obtained from TSAR with data taken on a Boeing 757 at the Air Force Phillips Lab., we hope to show that FDTD codes can serve as an important tool in the design and certification of U.S. commercial aircraft, helping American companies to produce safe, reliable air transportation.

  14. Supersonic through-flow fan engine and aircraft mission performance

    Science.gov (United States)

    Franciscus, Leo C.; Maldonado, Jaime J.

    1989-01-01

    A study was made to evaluate potential improvement to a commercial supersonic transport by powering it with supersonic through-flow fan turbofan engines. A Mach 3.2 mission was considered. The three supersonic fan engines considered were designed to operate at bypass ratios of 0.25, 0.5, and 0.75 at supersonic cruise. For comparison a turbine bypass turbojet was included in the study. The engines were evaluated on the basis of aircraft takeoff gross weight with a payload of 250 passengers for a fixed range of 5000 N.MI. The installed specific fuel consumption of the supersonic fan engines was 7 to 8 percent lower than that of the turbine bypass engine. The aircraft powered by the supersonic fan engines had takeoff gross weights 9 to 13 percent lower than aircraft powered by turbine bypass engines.

  15. Aircraft route planning based on digital map pre-treatment

    Directory of Open Access Journals (Sweden)

    Ran ZHEN

    2015-04-01

    Full Text Available Aiming at the flight path project in low complicated airspace, the influence of terrain conditions and surface threatening to aircraft flight are studied. Through the analysis of digital map and static threat, the paper explores the processing method of the digital map, and uses the Hermite function to process the map smoothly, reducing the searching range of optimal trajectory. By designing the terrain following, terrain avoidance and the way of avoiding a threat, the safety of aircraft can be guaranteed. In-depth analysis of particle swarm optimization (PSO algorithm realizes the three dimensional paths project before the aircraft performs a task. Through simulation, the difference of the maps before and after processing is shown, and offline programming of the three dimensional optimal path is achieved.

  16. Analysis and Synthesis of Tonal Aircraft Noise Sources

    Science.gov (United States)

    Allen, Matthew P.; Rizzi, Stephen A.; Burdisso, Ricardo; Okcu, Selen

    2012-01-01

    Fixed and rotary wing aircraft operations can have a significant impact on communities in proximity to airports. Simulation of predicted aircraft flyover noise, paired with listening tests, is useful to noise reduction efforts since it allows direct annoyance evaluation of aircraft or operations currently in the design phase. This paper describes efforts to improve the realism of synthesized source noise by including short term fluctuations, specifically for inlet-radiated tones resulting from the fan stage of turbomachinery. It details analysis performed on an existing set of recorded turbofan data to isolate inlet-radiated tonal fan noise, then extract and model short term tonal fluctuations using the analytic signal. Methodologies for synthesizing time-variant tonal and broadband turbofan noise sources using measured fluctuations are also described. Finally, subjective listening test results are discussed which indicate that time-variant synthesized source noise is perceived to be very similar to recordings.

  17. Aircraft noise footprint for Bucharest – Sophia flights

    Directory of Open Access Journals (Sweden)

    Luis MELIVEO

    2012-12-01

    Full Text Available Studies of impact noise have traditionally focused on landing and takeoff procedures in the airports vicinity. Beside these studies, en-route noise is considered an issue when we talk about noise in natural reservation or other populated sensitive areas and when it comes to designing a new aircraft engine. In these cases, the studies are focusing on the impact at ground level of the en route noise produced by aircraft at all the flights stages. This paper presents the results of the measurement performed for an A320 aircraft when flying en-route and the impact map for a flight from Bucharest – Sofia – Bucharest (OTP-SOF-OTP.

  18. NASA service experience with composite components. [for aircraft structures

    Science.gov (United States)

    Dexter, H. B.; Chapman, A. J.

    1980-01-01

    NASA Langley has been active in sponsoring flight service programs with advanced composites during the past decade. A broad data base and confidence in the durability of composite structures are being developed. Flight service experience is reported for more than 140 composite aircraft components with up to 8 years service and almost two million successful component flight hours. Composite components are being evaluated on Boeing, Douglas, and Lockheed transport aircraft. Components are currently under development for service evaluation on Bell and Sikorsky helicopters. Design concepts and inspection and maintenance results are reported for components currently in service. Components under development in the NASA Aircraft Energy Efficiency (ACEE) program are discussed. Results of flight, outdoor ground, and controlled laboratory environmental tests on composite materials used in the flight service programs are also presented.

  19. Low-Cost Composite Materials and Structures for Aircraft Applications

    Science.gov (United States)

    Deo, Ravi B.; Starnes, James H., Jr.; Holzwarth, Richard C.

    2003-01-01

    A survey of current applications of composite materials and structures in military, transport and General Aviation aircraft is presented to assess the maturity of composites technology, and the payoffs realized. The results of the survey show that performance requirements and the potential to reduce life cycle costs for military aircraft and direct operating costs for transport aircraft are the main reasons for the selection of composite materials for current aircraft applications. Initial acquisition costs of composite airframe components are affected by high material costs and complex certification tests which appear to discourage the widespread use of composite materials for aircraft applications. Material suppliers have performed very well to date in developing resin matrix and fiber systems for improved mechanical, durability and damage tolerance performance. The next challenge for material suppliers is to reduce material costs and to develop materials that are suitable for simplified and inexpensive manufacturing processes. The focus of airframe manufacturers should be on the development of structural designs that reduce assembly costs by the use of large-scale integration of airframe components with unitized structures and manufacturing processes that minimize excessive manual labor.

  20. The Aerosonde Robotic Aircraft: A New Paradigm for Environmental Observations.

    Science.gov (United States)

    Holland, G. J.; Webster, P. J.; Curry, J. A.; Tyrell, G.; Gauntlett, D.; Brett, G.; Becker, J.; Hoag, R.; Vaglienti, W.

    2001-05-01

    The Aerosonde is a small robotic aircraft designed for highly flexible and inexpensive operations. Missions are conducted in a completely robotic mode, with the aircraft under the command of a ground controller who monitors the mission. Here we provide an update on the Aerosonde development and operations and expand on the vision for the future, including instrument payloads, observational strategies, and platform capabilities. The aircraft was conceived in 1992 and developed to operational status in 1995-98, after a period of early prototyping. Continuing field operations and development since 1998 have led to the Aerosonde Mark 3, with ~2000 flight hours completed. A defined development path through to 2002 will enable the aircraft to become increasingly more robust with increased flexibility in the range and type of operations that can be achieved. An Aerosonde global reconnaissance facility is being developed that consists of launch and recovery sites dispersed around the globe. The use of satellite communications and internet technology enables an operation in which all aircraft around the globe are under the command of a single center. During operation, users will receive data at their home institution in near-real time via the virtual field environment, allowing the user to update the mission through interaction with the global command center. Sophisticated applications of the Aerosonde will be enabled by the development of a variety of interchangeable instrument payloads and the operation of Smart Aerosonde Clusters that allow a cluster of Aerosondes to interact intelligently in response to the data being collected.

  1. Aircraft Turbine Engine Control Research at NASA Glenn Research Center

    Science.gov (United States)

    Garg, Sanjay

    2013-01-01

    This paper provides an overview of the aircraft turbine engine control research at the NASA Glenn Research Center (GRC). A brief introduction to the engine control problem is first provided with a description of the state-of-the-art control law structure. A historical aspect of engine control development since the 1940s is then provided with a special emphasis on the contributions of GRC. With the increased emphasis on aircraft safety, enhanced performance, and affordability, as well as the need to reduce the environmental impact of aircraft, there are many new challenges being faced by the designers of aircraft propulsion systems. The Controls and Dynamics Branch (CDB) at GRC is leading and participating in various projects to develop advanced propulsion controls and diagnostics technologies that will help meet the challenging goals of NASA Aeronautics Research Mission programs. The rest of the paper provides an overview of the various CDB technology development activities in aircraft engine control and diagnostics, both current and some accomplished in the recent past. The motivation for each of the research efforts, the research approach, technical challenges, and the key progress to date are summarized.

  2. Residual stress measurements in laser clad aircraft aluminium alloys

    International Nuclear Information System (INIS)

    Fatigue and corrosion damage of structural components threatens the safety and availability of civil and military aircrafts. There is no sign of relief from these threats as civil and military aircrafts worldwide are continuously being pushed further into and past their initial design fatigue lives in tight financial circumstances. Given fatigue and corrosion damage often initiates at the surface and sub-surface of the components, there has been extensive research and development worldwide focused on advanced aircraft repair technologies and surface enhancement methods. The Deep Surface Rolling (DSR) is one of advanced surface enhancement technologies that can introduce deep compressive residual stresses into the surface of aircraft metallic structure to extend its fatigue life. For the development of cost-effective aircraft structural repair technologies such as laser cladding, in this study, aluminium alloy 7075-T651 specimens with simulated corrosion damage were repaired using laser cladding technology. The surface of the laser cladding region was then processed by DSR. The experimental results from subsequent fatigue testing of laser cladded baseline, DSR and post-heat treated laser cladded specimens discovered that the DSR process can significantly increase fatigue life in comparison with the ascladded baseline. The three dimensional residual stresses were measured by neutron diffraction and the results confirmed the beneficial compressive residual stresses at the cladding surface can be achieved in depth more than 1.0 mm.

  3. Structural Integrity Assessment of Reactor Containment Subjected to Aircraft Crash

    International Nuclear Information System (INIS)

    When an accident occurs at the NPP, containment building which acts as the last barrier should be assessed and analyzed structural integrity by internal loading or external loading. On many occasions that can occur in the containment internal such as LOCA(Loss Of Coolant Accident) are already reflected to design. Likewise, there are several kinds of accidents that may occur from the outside of containment such as earthquakes, hurricanes and strong wind. However, aircraft crash that at outside of containment is not reflected yet in domestic because NPP sites have been selected based on the probabilistic method. After intentional aircraft crash such as World Trade Center and Pentagon accident in US, social awareness for safety of infrastructure like NPP was raised world widely and it is time for assessment of aircraft crash in domestic. The object of this paper is assessment of reactor containment subjected to aircraft crash by FEM(Finite Element Method). In this paper, assessment of structural integrity of containment building subjected to certain aircraft crash was carried out. Verification of structure integrity of containment by intentional severe accident. Maximum stress 61.21MPa of horizontal shell crash does not penetrate containment. Research for more realistic results needed by steel reinforced concrete model

  4. Introduction to unmanned aircraft systems

    CERN Document Server

    Marshall, Douglas M; Hottman, Stephen B; Shappee, Eric; Most, Michael Thomas

    2011-01-01

    Introduction to Unmanned Aircraft Systems is the editors' response to their unsuccessful search for suitable university-level textbooks on this subject. A collection of contributions from top experts, this book applies the depth of their expertise to identify and survey the fundamentals of unmanned aircraft system (UAS) operations. Written from a nonengineering civilian operational perspective, the book starts by detailing the history of UASs and then explores current technology and what is expected for the future. Covering all facets of UAS elements and operation-including an examination of s

  5. Nondestructive testing of aging aircraft

    International Nuclear Information System (INIS)

    Aircraft fleet in the US military is getting old, averaging over 40 years. These old planes are planned to be used for additional 20-30 years. Some commercial fleets are getting older as well, though not on the same level. Many NDT methods are in practice and new ones being developed. Corrosion and fatigue are the two main sources of damage to aircraft structures and require cost-effective NDT methods to detect and characterize the damage. Current approaches to this difficult task reviewed.

  6. Optimization Design and Experimental Validation for Cabin Air Distribution of Civil Aircraft%民用飞机座舱空气分配优化设计与试验验证

    Institute of Scientific and Technical Information of China (English)

    汪光文; 吴成云; 杨智; 李革萍; 辛旭东

    2015-01-01

    以仿真分析和试验试飞为手段,对某型客机空气分配进行优化设计. 首先建立飞机座舱热载荷动态仿真模型,分析飞机驾驶舱及客舱新的供气需求;其次根据飞机空气分配管路实际构型建立Flowmaster仿真模型,并基于模型调节管路构型,以调整各舱室空气分配流量,实现驾驶舱和客舱的流量需求;最后将优化设计应用于民用飞机空气分配系统中,仿真分析和试验试飞验证结果吻合较好,说明了仿真技术手段的合理性.%In this paper, simulation analysis and experimental validation are applied for indicating air distribution configuration complied with the requirements. Firstly, the cabin/cockpit heat load dynamic model is set up and air supply requirement is analyzed. Secondly, to fulfill the target of air supply, Flowmaster model for one civil aircraft air distribution system is built and quantity of supplied air is adjusted based on the model. Lastly, ground/flight test is performed to validate simulation result similar with test result, and the air supplied to the cabin and cockpit meets the requirement of air worthiness standard and high level requirement. This attempt is the trial of civil aircraft air conditioning system distribution development and research, and the methods adopted are effectively enhancing the civil aircraft independent research capability.

  7. Estimation of nuclear power plant aircraft hazards

    International Nuclear Information System (INIS)

    The standard procedures for estimating aircraft risk to nuclear power plants provide a conservative estimate, which is adequate for most sites, which are not close to airports or heavily traveled air corridors. For those sites which are close to facilities handling large numbers of aircraft movements (airports or corridors), a more precise estimate of aircraft impact frequency can be obtained as a function of aircraft size. In many instances the very large commercial aircraft can be shown to have an acceptably small impact frequency, while the very small general aviation aircraft will not produce sufficiently serious impact to impair the safety-related functions. This paper examines the in between aircraft: primarily twin-engine, used for business, pleasure, and air taxi operations. For this group of aircraft the total impact frequency was found to be approximately once in one million years, the threshold above which further consideration of specific safety-related consequences would be required

  8. Versatile Electric Propulsion Aircraft Testbed Project

    Data.gov (United States)

    National Aeronautics and Space Administration — An all-electric aircraft testbed is proposed to provide a dedicated development environment for the rigorous study and advancement of electrically powered aircraft....

  9. Composite Axial Flow Propulsor for Small Aircraft

    Directory of Open Access Journals (Sweden)

    R. Poul

    2005-01-01

    Full Text Available 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. The skin of the blade is calculated as a laminate and the foam core as a solid. A static and dynamic analysis were made. The RTM technology is compared with other technologies and is described in detail. 

  10. Stroke Symbol Generation Software for Fighter Aircraft

    Directory of Open Access Journals (Sweden)

    G.K. Tripathi

    2013-03-01

    Full Text Available This paper gives an overview of the stroke symbol generation software developed by Hindustan Aeronautics Limited for fighter aircraft. This paper covers the working principle of head-up-display, overview of target hardware on which the developed software has been integrated and tested, software architecture, hardware software interfaces and design details of stroke symbol generation software. The paper also covers the issues related to stroke symbol quality which were encountered by the design team and the details about how the issues were resolved during integration and test phase.Defence Science Journal, 2013, 63(2, pp.153-156, DOI:http://dx.doi.org/10.14429/dsj.63.4257

  11. Improving aircraft energy efficiency

    Science.gov (United States)

    Povinelli, F. P.; Klineberg, J. M.; Kramer, J. J.

    1976-01-01

    Investigations conducted by a NASA task force concerning the development of aeronautical fuel-conservation technology are considered. The task force estimated the fuel savings potential, prospects for implementation in the civil air-transport fleet, and the impact of the technology on air-transport fuel use. Propulsion advances are related to existing engines in the fleet, to new production of current engine types, and to new engine designs. Studies aimed at the evolutionary improvement of aerodynamic design and a laminar flow control program are discussed and possibilities concerning the use of composite structural materials are examined.

  12. Residents' Annoyance Responses to Aircraft Noise Events

    OpenAIRE

    United States, National Aeronautics and Space Administration

    1983-01-01

    In a study conducted in the vicinity of Salt Lake City International Airport, community residents reported their annoyance with individual aircraft flyovers during rating sessions conducted in their homes. Annoyance ratings were obtained at different times of the day. Aircraft noise levels were measured, and other characteristics of the aircraft were noted by trained observers. Metrics commonly used for assessing aircraft noise were compared, but none performed significantly better than A-...

  13. The NASA Aircraft Energy Efficiency program

    Science.gov (United States)

    Klineberg, J. M.

    1979-01-01

    A review is provided of the goals, objectives, and recent progress in each of six aircraft energy efficiency programs aimed at improved propulsive, aerodynamic and structural efficiency for future transport aircraft. Attention is given to engine component improvement, an energy efficient turbofan engine, advanced turboprops, revolutionary gains in aerodynamic efficiency for aircraft of the late 1990s, laminar flow control, and composite primary aircraft structures.

  14. Development of fiber optic sensors for advanced aircraft testing and control

    Science.gov (United States)

    Meller, Scott A.; Jones, Mark E.; Wavering, Thomas A.; Kozikowski, Carrie L.; Murphy, Kent A.

    1999-02-01

    Optical fiber sensors, because of the small size, low weight, extremely high information carrying capability, immunity to electromagnetic interference, and large operational temperature range, provide numerous advantages over conventional electrically based sensors. This paper presents preliminary results from optical fiber sensor design for monitoring acceleration on aircraft. Flight testing of the final accelerometer design will be conducted on the F-18 Systems Research Aircraft at NASA Dryden Flight Research Center in Edwards, CA.

  15. Adjoint gradient-based approach for aerodynamic optimization of transport aircraft

    OpenAIRE

    Ilic, Caslav

    2013-01-01

    Aerodynamic design of transport aircraft has been steadily improved over past several decades, to the point where today highly-detailed shape control is needed to achieve further improvements. Aircraft manufacturers are therefore increasingly looking into formal optimization methods, driving high-fidelity CFD analysis of finely-parametrized candidate designs. We present an adjoint gradient-based approach for maximizing the aerodynamic performance index relevant to cruise-climb mission segment...

  16. Studying aeroelastic behavior of aircraft with NeoCASS. : The Danbus configuration

    OpenAIRE

    Sánches Manzano, María De Las Mercedes

    2011-01-01

    This Master Thesis assesses the performance of NeoCASS software as a tool for structural sizing for deformable aircraft at conceptual design level. NeoCASS is a collection of Matlab modules included in CEASIOM. Some testcases (simple wing model, TCR, Danbus, Agard 445.6 wing) are computed to evaluate the aeroelastic behavior and provide additional validation on the structural models NeoCASS computes Finally, Danbus, a new conceptual design aircraft, is analyzed with the software.

  17. 14 CFR 91.117 - Aircraft speed.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Aircraft speed. 91.117 Section 91.117... speed. (a) Unless otherwise authorized by the Administrator, no person may operate an aircraft below 10... than the maximum speed prescribed in this section, the aircraft may be operated at that minimum speed....

  18. 19 CFR 122.37 - Precleared aircraft.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Precleared aircraft. 122.37 Section 122.37 Customs... AIR COMMERCE REGULATIONS Landing Requirements § 122.37 Precleared aircraft. (a) Application. This section applies when aircraft carrying crew, passengers and baggage, or merchandise which has...

  19. 14 CFR 252.13 - Small aircraft.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Small aircraft. 252.13 Section 252.13 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS SMOKING ABOARD AIRCRAFT § 252.13 Small aircraft. Air carriers shall prohibit smoking on...

  20. 43 CFR 423.41 - Aircraft.

    Science.gov (United States)

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Aircraft. 423.41 Section 423.41 Public... Aircraft. (a) You must comply with any applicable Federal, State, and local laws, and with any additional... this part 423, with respect to aircraft landings, takeoffs, and operation on or in the proximity...