Sample records for aircraft design
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1997-01-01
Successful commercialization of the AirCraft SYNThesis (ACSYNT) tool has resulted in the creation of Phoenix Integration, Inc. ACSYNT has been exclusively licensed to the company, an outcome of a seven year, $3 million effort to provide unique software technology to a focused design engineering market. Ames Research Center formulated ACSYNT and in working with the Virginia Polytechnic Institute CAD Laboratory, began to design and code a computer-aided design for ACSYNT. Using a Joint Sponsored Research Agreement, Ames formed an industry-government-university alliance to improve and foster research and development for the software. As a result of the ACSYNT Institute, the software is becoming a predominant tool for aircraft conceptual design. ACSYNT has been successfully applied to high- speed civil transport configuration, subsonic transports, and supersonic fighters.
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ERGONOMIC DESIGN OF AIRCRAFT COCKPIT
Directory of Open Access Journals (Sweden)
CÎMPIAN Ionuţ
2012-09-01
Full Text Available This paper presents a model for an ergonomic design of an aircraft cockpit with the specification and verification with respect to the new European Aviation Safety Agency (EASA and Federal Aviation Administration (FAA requirements. The goal is to expressing the concepts on which the aircraft cockpit design are based.
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ERGONOMIC DESIGN OF AIRCRAFT COCKPIT
Directory of Open Access Journals (Sweden)
CÎMPIAN Ionuţ
2011-06-01
Full Text Available This paper presents a model for an ergonomic design of an aircraft cockpit with the specification and verification with respect to the new European Aviation Safety Agency (EASA and Federal Aviation Administration (FAA requirements. The goal is to expressing the concepts on which the aircraft cockpit design is based.
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Structural design for aircraft impact loading
International Nuclear Information System (INIS)
Schmidt, R.; Heckhausen, H.; Chen, C.; Rieck, P.J.; Lemons, G.W.
1977-01-01
The Soft Shell-Hardcore approach to nuclear power plant auxiliary structure design was developed to attenuate the crash effects of impacting aircraft. This report is an initial investigation into defining the important structural features involved that would allow the Soft Shell-Hardcore design to successfully sustain the postulated aircraft impact. Also specified for purposes of this study are aircraft impact locations and the type and velocity of impacting aircraft. The purpose of this initial investigation is to determine the feasibility of the two 0.5 m thick walls of the Soft Shell with the simplest possible mathematical model
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Aircraft family design using enhanced collaborative optimization
Roth, Brian Douglas
Significant progress has been made toward the development of multidisciplinary design optimization (MDO) methods that are well-suited to practical large-scale design problems. However, opportunities exist for further progress. This thesis describes the development of enhanced collaborative optimization (ECO), a new decomposition-based MDO method. To support the development effort, the thesis offers a detailed comparison of two existing MDO methods: collaborative optimization (CO) and analytical target cascading (ATC). This aids in clarifying their function and capabilities, and it provides inspiration for the development of ECO. The ECO method offers several significant contributions. First, it enhances communication between disciplinary design teams while retaining the low-order coupling between them. Second, it provides disciplinary design teams with more authority over the design process. Third, it resolves several troubling computational inefficiencies that are associated with CO. As a result, ECO provides significant computational savings (relative to CO) for the test cases and practical design problems described in this thesis. New aircraft development projects seldom focus on a single set of mission requirements. Rather, a family of aircraft is designed, with each family member tailored to a different set of requirements. This thesis illustrates the application of decomposition-based MDO methods to aircraft family design. This represents a new application area, since MDO methods have traditionally been applied to multidisciplinary problems. ECO offers aircraft family design the same benefits that it affords to multidisciplinary design problems. Namely, it simplifies analysis integration, it provides a means to manage problem complexity, and it enables concurrent design of all family members. In support of aircraft family design, this thesis introduces a new wing structural model with sufficient fidelity to capture the tradeoffs associated with component
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Conceptual design of high speed supersonic aircraft: A brief review on SR-71 (Blackbird) aircraft
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.
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Directory of Open Access Journals (Sweden)
Qinghua Zeng
2015-07-01
Full Text Available This article proposes a linear matrix inequality–based robust controller design approach to implement the synchronous design of aircraft control discipline and other disciplines, in which the variation in design parameters is treated as equivalent perturbations. Considering the complicated mapping relationships between the coefficient arrays of aircraft motion model and the aircraft design parameters, the robust controller designed is directly based on the variation in these coefficient arrays so conservative that the multidisciplinary design optimization problem would be too difficult to solve, or even if there is a solution, the robustness of design result is generally poor. Therefore, this article derives the uncertainty model of disciplinary design parameters based on response surface approximation, converts the design problem of the robust controller into a problem of solving a standard linear matrix inequality, and theoretically gives a less conservative design method of the robust controller which is based on the variation in design parameters. Furthermore, the concurrent subspace approach is applied to the multidisciplinary system with this kind of robust controller in the design loop. A multidisciplinary design optimization of a tailless aircraft as example is shown that control discipline can be synchronous optimal design with other discipline, especially this method will greatly reduce the calculated amount of multidisciplinary design optimization and make multidisciplinary design optimization results more robustness of flight performance.
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Flow Control Enabled Aircraft Design
National Research Council Canada - National Science Library
Nangia, Rajendar
2004-01-01
...: Many future advanced aircraft concepts being considered by the Air Force fall outside the current aerodynamic design practice and will rely heavily on the use of flow control technology to optimize flight performance...
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Structural analysis at aircraft conceptual design stage
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
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Control Design for a Generic Commercial Aircraft Engine
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
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V/STOL tilt rotor aircraft study. Volume 2: Preliminary design of research aircraft
1972-01-01
A preliminary design study was conducted to establish a minimum sized, low cost V/STOL tilt-rotor research aircraft with the capability of performing proof-of-concept flight research investigations applicable to a wide range of useful military and commercial configurations. The analysis and design approach was based on state-of-the-art methods and maximum use of off-the-shelf hardware and systems to reduce development risk, procurement cost and schedules impact. The rotors to be used are of 26 foot diameter and are the same as currently under construction and test as part of NASA Tilt-Rotor Contract NAS2-6505. The aircraft has a design gross weight of 12,000 lbs. The proposed engines to be used are Lycoming T53-L-13B rated at 1550 shaft horsepower which are fully qualified. A flight test investigation is recommended which will determine the capabilities and limitations of the research aircraft.
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Structural design for aircraft impact loading
International Nuclear Information System (INIS)
Schmidt, R.; Heckhausen, H.; Chen, C.; Rieck, P.J.; Lemons, G.W.
1977-01-01
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 typical approach on recent projects has been the hardening of safety-related buildings and/or protection of redundant safety-related equipment through separation. 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. Conservatively calculated loads resulting from these are in some cases quite severe. The reactor auxiliary system building (Soft Shell Hardcore design) 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 radioactivity (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. This investigation determines the feasibility of two 0.5 m thick walls of the Soft Shell with the simplest possible mathematical model. (Auth.)
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Modeling Programs Increase Aircraft Design Safety
2012-01-01
Flutter may sound like a benign word when associated with a flag in a breeze, a butterfly, or seaweed in an ocean current. When used in the context of aerodynamics, however, it describes a highly dangerous, potentially deadly condition. Consider the case of the Lockheed L-188 Electra Turboprop, an airliner that first took to the skies in 1957. Two years later, an Electra plummeted to the ground en route from Houston to Dallas. Within another year, a second Electra crashed. In both cases, all crew and passengers died. Lockheed engineers were at a loss as to why the planes wings were tearing off in midair. For an answer, the company turned to NASA s Transonic Dynamics Tunnel (TDT) at Langley Research Center. At the time, the newly renovated wind tunnel offered engineers the capability of testing aeroelastic qualities in aircraft flying at transonic speeds near or just below the speed of sound. (Aeroelasticity is the interaction between aerodynamic forces and the structural dynamics of an aircraft or other structure.) Through round-the-clock testing in the TDT, NASA and industry researchers discovered the cause: flutter. Flutter occurs when aerodynamic forces acting on a wing cause it to vibrate. As the aircraft moves faster, certain conditions can cause that vibration to multiply and feed off itself, building to greater amplitudes until the flutter causes severe damage or even the destruction of the aircraft. Flutter can impact other structures as well. Famous film footage of the Tacoma Narrows Bridge in Washington in 1940 shows the main span of the bridge collapsing after strong winds generated powerful flutter forces. In the Electra s case, faulty engine mounts allowed a type of flutter known as whirl flutter, generated by the spinning propellers, to transfer to the wings, causing them to vibrate violently enough to tear off. Thanks to the NASA testing, Lockheed was able to correct the Electra s design flaws that led to the flutter conditions and return the
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QCGAT aircraft/engine design for reduced noise and emissions
Lanson, L.; Terrill, K. M.
1980-01-01
The high bypass ratio QCGAT engine played an important role in shaping the aircraft design. The aircraft which evolved is a sleek, advanced design, six-place aircraft with 3538 kg (7,800 lb) maximum gross weight. It offers a 2778 kilometer (1500 nautical mile) range with cruise speed of 0.5 Mach number and will take-off and land on the vast majority of general aviation airfields. Advanced features include broad application of composite materials and a supercritical wing design with winglets. Full-span fowler flaps were introduced to improve landing capability. Engines are fuselage-mounted with inlets over the wing to provide shielding of fan noise by the wing surfaces. The design objectives, noise, and emission considerations, engine cycle and engine description are discussed as well as specific design features.
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Design Of Vertical Take-Off And Landing VTOL Aircraft System
Directory of Open Access Journals (Sweden)
Win Ko Ko Oo
2017-04-01
Full Text Available Vertical Take Off and Landing Vehicles VTOL are the ones which can take off and land from the same place without need of long runway. This paper presents the design and implementation of tricopter mode and aircraft mode for VTOL aircraft system. Firstly the aircraft design is considered for VTOL mode. And then the mathematical model of the VTOL aircraft is applied to test stability. In this research the KK 2.1 flight controller is used for VTOL mode and aircraft mode. The first part is to develop the VTOL mode and the next part is the transition of VTOL mode to aircraft mode. This paper gives brief idea about numerous types of VTOLs and their advantages over traditional aircraftsand insight to various types of tricopter and evaluates their configurations.
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Aircraft impact design for SGHWR containment
International Nuclear Information System (INIS)
Bartley, R.; Davies, I.Ll.
1976-01-01
A description is given of the influence on the design of the containment structure to meet the recent safety requirements in the UK of specified external hazards. Methods of preliminary design for the case of aircraft impact are described to enable structural sizes to be determined. (author)
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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.
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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.
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Data management in an object-oriented distributed aircraft conceptual design environment
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
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Obrien, W. J.
1976-01-01
Two types of lift/cruise fan technology aircraft were conceptually designed. One aircraft used turbotip fans pneumatically interconnected to three gas generators, and the other aircraft used variable pitch fans mechanically interconnected to three turboshaft engines. The components of each propulsion transmission system were analyzed and designed to the depth necessary to determine areas of risk, development methods, performance, weights and costs. The types of materials and manufacturing processes were identified to show that the designs followed a low cost approach. The lift/cruise fan thrust vectoring hoods, which are applicable to either aircraft configuration, were also evaluated to assure a low cost/low risk approach.
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1975-01-01
Technology flight vehicles were defined for three different approaches which demonstrate the concept and characteristics of the multipurpose aircraft established for Navy missions. The propulsion system used for the various technology flight vehicles was representative of that established for the multipurpose aircraft. Existing J97-GE100 gas generators were selected based on cost, availability and exhaust characteristics. The LF459 fans were also selected and are compatible with both technology and operational vehicles. To comply with the design guideline safety criteria, it was determined that three gas generators were required to provide engine out safety in the hover flight mode. The final propulsion system established for the technology aircraft was three existing J97 gas generators powering three LF459 fans. Different aircraft candidates were evaluated for application to the three designated design approaches. Each configuration was evaluated on the basis of (1) propulsion system integration, (2) modification required, (3) pilot's visibility, (4) payload volume, and (5) adaptability to compatible location of center-of-gravity/aerodynamic center and thrust center.
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Preliminary Design of Aerial Spraying System for Microlight Aircraft
Omar, Zamri; Idris, Nurfazliawati; Rahim, M. Zulafif
2017-10-01
Undoubtedly agricultural is an important sector because it provides essential nutrients for human, and consequently is among the biggest sector for economic growth worldwide. It is crucial to ensure crops production is protected from any plant diseases and pests. Thus aerial spraying system on crops is developed to facilitate farmers to for crops pests control and it is very effective spraying method especially for large and hilly crop areas. However, the use of large aircraft for aerial spaying has a relatively high operational cost. Therefore, microlight aircraft is proposed to be used for crops aerial spraying works for several good reasons. In this paper, a preliminary design of aerial spraying system for microlight aircraft is proposed. Engineering design methodology is adopted in the development of the aerial sprayer and steps involved design are discussed thoroughly. A preliminary design for the microlight to be attached with an aerial spraying system is proposed.
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Improving the Aircraft Design Process Using Web-based Modeling and Simulation
Reed, John A.; Follen, Gregory J.; Afjeh, Abdollah A.
2003-01-01
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 muitifidelity 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.
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Seat Capacity Selection for an Advanced Short-Haul Aircraft Design
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.
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International Nuclear Information System (INIS)
Kar, A.K.
1978-01-01
Aircraft impact against nuclear power plant structures leads to both local and overall effects on the structure. Among the local effects, backface spalling is most important. The overall effects of impact on structural stability are commonly evaluated in terms of the adequacy of the structure in flexure and shear. Empirical formulas are presented for the determination of local effects of aircraft impact on nuclear power plant facilities. The formulas lead to easy and reasonable estimates of the thickness required to prevent backface spalling. The impactive load depends upon the collapse load of the fuselage, its collapse mechanism, mass distribution and the impact velocity. A simplified method is given for evaluating the design load. The time history, obtained by the proposed method, closely resembles those obtained by more rigorous methods. Procedures for obtaining shear and flexural strengths of concrete walls or roofs, subjected to impact, are provided. The span-to-depth ratio is considered. Recommendations are made on the available ductility ratio and structural behavior. (Author)
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Simulation Packages Expand Aircraft Design Options
2013-01-01
In 2001, NASA released a new approach to computational fluid dynamics that allows users to perform automated analysis on complex vehicle designs. In 2010, Palo Alto, California-based Desktop Aeronautics acquired a license from Ames Research Center to sell the technology. Today, the product assists organizations in the design of subsonic aircraft, space planes, spacecraft, and high speed commercial jets.
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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 ...
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A design for KLM Aircraft Services' Planning-rostering indeling chain
Dekkers, K J.P.
2010-01-01
This report describes a Logistics Management Systems design project that is performed at KLM Aircraft Services (AS). AS is the part of KLM that is responsible for a large portion of the tasks that must be done to an aircraft that has landed and has to be used again. When an aircraft has landed the
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High-Fidelity Multidisciplinary Design Optimization of Aircraft Configurations
Martins, Joaquim R. R. A.; Kenway, Gaetan K. W.; Burdette, David; Jonsson, Eirikur; Kennedy, Graeme J.
2017-01-01
To evaluate new airframe technologies we need design tools based on high-fidelity models that consider multidisciplinary interactions early in the design process. The overarching goal of this NRA is to develop tools that enable high-fidelity multidisciplinary design optimization of aircraft configurations, and to apply these tools to the design of high aspect ratio flexible wings. We develop a geometry engine that is capable of quickly generating conventional and unconventional aircraft configurations including the internal structure. This geometry engine features adjoint derivative computation for efficient gradient-based optimization. We also added overset capability to a computational fluid dynamics solver, complete with an adjoint implementation and semiautomatic mesh generation. We also developed an approach to constraining buffet and started the development of an approach for constraining utter. On the applications side, we developed a new common high-fidelity model for aeroelastic studies of high aspect ratio wings. We performed optimal design trade-o s between fuel burn and aircraft weight for metal, conventional composite, and carbon nanotube composite wings. We also assessed a continuous morphing trailing edge technology applied to high aspect ratio wings. This research resulted in the publication of 26 manuscripts so far, and the developed methodologies were used in two other NRAs. 1
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Evaluation of materials and design modifications for aircraft brakes
Ho, T. L.; Kennedy, F. E.; Peterson, M. B.
1975-01-01
A test program is described which was carried out to evaluate several proposed design modifications and several high-temperature friction materials for use in aircraft disk brakes. The evaluation program was carried out on a specially built test apparatus utilizing a disk brake and wheel half from a small het aircraft. The apparatus enabled control of brake pressure, velocity, and braking time. Tests were run under both constant and variable velocity conditions and covered a kinetic energy range similar to that encountered in aircraft brake service. The results of the design evaluation program showed that some improvement in brake performance can be realized by making design changes in the components of the brake containing friction material. The materials evaluation showed that two friction materials show potential for use in aircraft disk brakes. One of the materials is a nickel-based sintered composite, while the other is a molybdenum-based material. Both materials show much lower wear rates than conventional copper-based materials and are better able to withstand the high temperatures encountered during braking. Additional materials improvement is necessary since both materials show a significant negative slope of the friction-velocity curve at low velocities.
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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.
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1975-01-01
Aircraft were designed and sized to meet Navy mission requirements. Five missions were established for evaluation: anti-submarine warfare (ASW), surface attack (SA), combat search and rescue (CSAR), surveillance (SURV), and vertical on-board delivery (VOD). All missions were performed with a short takeoff and a vertical landing. The aircraft were defined using existing J97-GE gas generators or reasonable growth derivatives in conjunction with turbotip fans reflecting LF460 type technology. The multipurpose aircraft configuration established for U.S. Navy missions utilizes the turbotip driven lift/cruise fan concept for V/STOL aircraft.
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Intuitive thinking of design and redesign on innovative aircraft cabin simulator
Tan, C.F.; Chen, W.; Rauterberg, G.W.M.
2009-01-01
In this paper, the intuition approach in the design and redesign of the environmental friendly innovative aircraft cabin simulator is presented. The simulator is a testbed that was designed and built for research on aircraft passenger comfort improvement of long haul air travel. The simulation
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Collaborative Systems Driven Aircraft Configuration Design Optimization
Shiva Prakasha, Prajwal; Ciampa, Pier Davide; Nagel, Björn
2016-01-01
A Collaborative, Inside-Out Aircraft Design approach is presented in this paper. An approach using physics based analysis to evaluate the correlations between the airframe design, as well as sub-systems integration from the early design process, and to exploit the synergies within a simultaneous optimization process. Further, the disciplinary analysis modules involved in the optimization task are located in different organization. Hence, the Airframe and Subsystem design tools are integrated ...
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Soule, V. A.; Badri-Nath, Y.
1973-01-01
The results of a study of the use of composite materials in the wing of a tilt rotor aircraft are presented. An all-metal tilt rotor aircraft was first defined to provide a basis for comparing composite with metal structure. A configuration study was then done in which the wing of the metal aircraft was replaced with composite wings of varying chord and thickness ratio. The results of this study defined the design and performance benefits obtainable with composite materials. Based on these results the aircraft was resized with a composite wing to extend the weight savings to other parts of the aircraft. A wing design was then selected for detailed structural analysis. A development plan including costs and schedules to develop this wing and incorporate it into a proposed flight research tilt rotor vehicle has been devised.
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Impact of New large Aircraft on Airport Design
1998-03-01
The object of this project is to assess the impact of the introduction of proposed new large aircraft (NLA) on current airport design standards and administered by the Federal Aviation Administration (FAA). This report identifies several key design a...
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Desaid : the development of an expert system for aircraft initial design
Nah, Seung-Hyeog
1991-01-01
As all engineering works are a blend of theory and empiricism, aircraft design, by its nature, represents a mixture of aircraft designer's knowledge obtained from aeronautical engineering disciplines and its usage combined with his experience. This means not only the application but also the integration of all the fundamental knowledge of aerodynamics, structure, propulsion, stability and control, operational and economic aspects, etc., based upon the designer's jud...
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Automatic control design procedures for restructurable aircraft control
Looze, D. P.; Krolewski, S.; Weiss, J.; Barrett, N.; Eterno, J.
1985-01-01
A simple, reliable automatic redesign procedure for restructurable control is discussed. This procedure is based on Linear Quadratic (LQ) design methodologies. It employs a robust control system design for the unfailed aircraft to minimize the effects of failed surfaces and to extend the time available for restructuring the Flight Control System. The procedure uses the LQ design parameters for the unfailed system as a basis for choosing the design parameters of the failed system. This philosophy alloys the engineering trade-offs that were present in the nominal design to the inherited by the restructurable design. In particular, it alloys bandwidth limitations and performance trade-offs to be incorporated in the redesigned system. The procedure also has several other desirable features. It effectively redistributes authority among the available control effectors to maximize the system performance subject to actuator limitations and constraints. It provides a graceful performance degradation as the amount of control authority lessens. When given the parameters of the unfailed aircraft, the automatic redesign procedure reproduces the nominal control system design.
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Design and Analysis of Winglets for Military Aircraft
1976-02-03
Company to determine the aerodynamic characteristics and performance benefits from winglets on the KC-135 aircraft. Unclassified SECURITY CLASSIFICATION...1 II ANALYSIS OF WINGLETS ...... ............................................ 3 A Aerodynamic ...were estimated and compared to the conventional design. The aerodynamic shape of the winglet was designed for the KC-135 and this design was then used
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Multidisciplinary design and optimization (MDO) methodology for the aircraft conceptual design
Iqbal, Liaquat Ullah
An integrated design and optimization methodology has been developed for the conceptual design of an aircraft. The methodology brings higher fidelity Computer Aided Design, Engineering and Manufacturing (CAD, CAE and CAM) Tools such as CATIA, FLUENT, ANSYS and SURFCAM into the conceptual design by utilizing Excel as the integrator and controller. The approach is demonstrated to integrate with many of the existing low to medium fidelity codes such as the aerodynamic panel code called CMARC and sizing and constraint analysis codes, thus providing the multi-fidelity capabilities to the aircraft designer. The higher fidelity design information from the CAD and CAE tools for the geometry, aerodynamics, structural and environmental performance is provided for the application of the structured design methods such as the Quality Function Deployment (QFD) and the Pugh's Method. The higher fidelity tools bring the quantitative aspects of a design such as precise measurements of weight, volume, surface areas, center of gravity (CG) location, lift over drag ratio, and structural weight, as well as the qualitative aspects such as external geometry definition, internal layout, and coloring scheme early in the design process. The performance and safety risks involved with the new technologies can be reduced by modeling and assessing their impact more accurately on the performance of the aircraft. The methodology also enables the design and evaluation of the novel concepts such as the blended (BWB) and the hybrid wing body (HWB) concepts. Higher fidelity computational fluid dynamics (CFD) and finite element analysis (FEA) allow verification of the claims for the performance gains in aerodynamics and ascertain risks of structural failure due to different pressure distribution in the fuselage as compared with the tube and wing design. The higher fidelity aerodynamics and structural models can lead to better cost estimates that help reduce the financial risks as well. This helps in
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Automation of the aircraft design process
Heldenfels, R. R.
1974-01-01
The increasing use of the computer to automate the aerospace product development and engineering process is examined with emphasis on structural analysis and design. Examples of systems of computer programs in aerospace and other industries are reviewed and related to the characteristics of aircraft design in its conceptual, preliminary, and detailed phases. Problems with current procedures are identified, and potential improvements from optimum utilization of integrated disciplinary computer programs by a man/computer team are indicated.
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Teaching Risk Analysis in an Aircraft Gas Turbine Engine Design Capstone Course
2016-01-01
support the required performance specifications (Brandt, 2004) ( Raymer , 1989). There is no specific step to treat a selected design performance...a Design Perspective, 2nd ed.: AIAA Education Series, 2004. Raymer , Daniel P. 1989. Aircraft Design: A Conceptual Approach.: AIAA Educational...Mattingly, Jack D., Heiser, William H., Pratt, David T. 2002. Aircraft Engine Design, 2nd ed.: AIAA Education Series, 2002. Drews, Robert W. 2006. The
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Conceptual design of hybrid-electric transport aircraft
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
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Methodology for designing aircraft having optimal sound signatures
Sahai, A.K.; Simons, D.G.
2017-01-01
This paper presents a methodology with which aircraft designs can be modified such that they produce optimal sound signatures on the ground. With optimal sound it is implied in this case sounds that are perceived as less annoying by residents living near airport vicinities. A novel design and
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Optimal Input Design for Aircraft Parameter Estimation using Dynamic Programming Principles
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.
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Parallel calculation of sensitivity derivatives for aircraft design using automatic differentiation
Energy Technology Data Exchange (ETDEWEB)
Bischof, C.H.; Knauff, T.L. Jr. [Argonne National Lab., IL (United States); Green, L.L.; Haigler, K.J. [National Aeronautics and Space Administration, Hampton, VA (United States). Langley Research Center
1994-01-01
Realistic multidisciplinary design optimization (MDO) of advanced aircraft using state-of-the-art computers is an extremely challenging problem from both the physical modelling and computer science points of view. In order to produce an efficient aircraft design, many trade-offs must be made among the various physical design variables. Similarly, in order to produce an efficient design scheme, many trade-offs must be made among the various MDO implementation options. In this paper, we examine the effects of vectorization and coarse-grained parallelization on the SD calculation using a representative example taken from a transonic transport design problem.
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A generic tool for cost estimating in aircraft design
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
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Aircraft Engine Thrust Estimator Design Based on GSA-LSSVM
Sheng, Hanlin; Zhang, Tianhong
2017-08-01
In view of the necessity of highly precise and reliable thrust estimator to achieve direct thrust control of aircraft engine, based on support vector regression (SVR), as well as least square support vector machine (LSSVM) and a new optimization algorithm - gravitational search algorithm (GSA), by performing integrated modelling and parameter optimization, a GSA-LSSVM-based thrust estimator design solution is proposed. The results show that compared to particle swarm optimization (PSO) algorithm, GSA can find unknown optimization parameter better and enables the model developed with better prediction and generalization ability. The model can better predict aircraft engine thrust and thus fulfills the need of direct thrust control of aircraft engine.
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Concurrent airline fleet allocation and aircraft design with profit modeling for multiple airlines
Govindaraju, Parithi
A "System of Systems" (SoS) approach is particularly beneficial in analyzing complex large scale systems comprised of numerous independent systems -- each capable of independent operations in their own right -- that when brought in conjunction offer capabilities and performance beyond the constituents of the individual systems. The variable resource allocation problem is a type of SoS problem, which includes the allocation of "yet-to-be-designed" systems in addition to existing resources and systems. The methodology presented here expands upon earlier work that demonstrated a decomposition approach that sought to simultaneously design a new aircraft and allocate this new aircraft along with existing aircraft in an effort to meet passenger demand at minimum fleet level operating cost for a single airline. The result of this describes important characteristics of the new aircraft. The ticket price model developed and implemented here enables analysis of the system using profit maximization studies instead of cost minimization. A multiobjective problem formulation has been implemented to determine characteristics of a new aircraft that maximizes the profit of multiple airlines to recognize the fact that aircraft manufacturers sell their aircraft to multiple customers and seldom design aircraft customized to a single airline's operations. The route network characteristics of two simple airlines serve as the example problem for the initial studies. The resulting problem formulation is a mixed-integer nonlinear programming problem, which is typically difficult to solve. A sequential decomposition strategy is applied as a solution methodology by segregating the allocation (integer programming) and aircraft design (non-linear programming) subspaces. After solving a simple problem considering two airlines, the decomposition approach is then applied to two larger airline route networks representing actual airline operations in the year 2005. The decomposition strategy serves
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AIRCRAFT POWER SUPPLY SYSTEM DESIGN PROCESS AS AN AUTOMATION OBJECT
Directory of Open Access Journals (Sweden)
Boris V. Zhmurov
2018-01-01
Full Text Available The process of designing aviation electrical power systems (EPS is related to the need to fulfill a number of requirements of normative and technical documents and to conduct a large number of calculations. Experience has shown that it is not possible to obtain reliable initial data on the nature and magnitude of electricity consumption by electricity receivers (end users at the early stages of design. The composition of the electric power receivers and the power consumption of electricity during the design process are repeatedly changed. This leads to the need to repeatedly perform tasks related to the synthesis of primary and secondary systems of generation and calculation.The desire to improve the efficiency of EPS led to the emergence of new standardized types of electrical energy - 270 V DC and 380 V three-phase AC of stable and unstable frequency. It follows that it is possible to implement a rather large number of options for EPS structures, and there may be several secondary EPS or, in general, EPS of a third or higher level.The lack of ready-made aviation energy converters implies the impossibility of using ready-made components, and the development of specific devices should be coordinated with the development of EPS. In this case, one of the results of EPS design will be a set of requirements for the devices and units of the EPS projected.In any case, the design process for EPS aircraft requires a lot of iterations that take into account the change in both the raw data and the constraints on the EPS elements and the design process itself.The traditional approach to the design of EPS aircraft, assuming the knowledge of the designer of dozens of GOSTs (State All-Union standards and OSTs (All-Union standarts regulating the design stages of EPS, as well as the existence of standard EPS structures, from which a specific choice is made, is practically impossible at present. The only way to consciously approach the problem of designing EPS
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Design and test of aircraft engine isolators for reduced interior noise
Unruh, J. F.; Scheidt, D. C.
1982-01-01
Improved engine vibration isolation was proposed to be the most weight and cost efficient retrofit structure-borne noise control measure for single engine general aviation aircraft. A study was carried out the objectives: (1) to develop an engine isolator design specification for reduced interior noise transmission, (2) select/design candidate isolators to meet a 15 dB noise reduction design goal, and (3) carry out a proof of concept evaluation test. Analytical model of the engine, vibration isolators and engine mount structure were coupled to an empirical model of the fuselage for noise transmission evaluation. The model was used to develop engine isolator dynamic properties design specification for reduced noise transmission. Candidate isolators ere chosen from available product literature and retrofit to a test aircraft. A laboratory based test procedure was then developed to simulate engine induced noise transmission in the aircraft for a proof of concept evaluation test. Three candidate isolator configurations were evaluated for reduced structure-borne noise transmission relative to the original equipment isolators.
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An Integrated Approach to Aircraft Modelling and Flight Control Law Design
Looye, G.H.N.
2008-01-01
The design of flight control laws (FCLs) for automatic and manual (augmented) control of aircraft is a complicated task. FCLs have to fulfil large amounts of performance criteria and must work reliably in all flight conditions, for all aircraft configurations, and in adverse weather conditions.
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Multidisciplinary Design and Optimization Framework for Aircraft Box Structures
Van Dijk, R.E.C.; Zhao, X.; Wang, H.; Van Dalen, F.
2012-01-01
Competitive aircraft box structures are a perfect compromise between weight and price. The conceptual design process of these structures is a typical Multidisciplinary Design and Optimization effort, normally conducted by human engineers. The iterative nature of MDO turns development into a long and
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Future aircraft cabins and design thinking: optimisation vs. win-win scenarios
Directory of Open Access Journals (Sweden)
A. Hall
2013-06-01
Full Text Available With projections indicating an increase in mobility over the next few decades and annual flight departures expected to rise to over 16 billion by 2050, there is a demand for the aviation industry and associated stakeholders to consider new forms of aircraft and technology. Customer requirements are recognized as a key driver in business. The airline is the principal customer for the aircraft manufacture. The passenger is, in turn, the airline's principal customer but they are just one of several stakeholders that include aviation authorities, airport operators, air-traffic control and security agencies. The passenger experience is a key differentiator used by airlines to attract and retain custom and the fuselage that defines the cabin envelope for the in-flight passenger experience and cabin design therefore receives significant attention for new aircraft, service updates and refurbishments. Decision making in design is crucial to arriving at viable and worthwhile cabin formats. Too little innovation will result in an aircraft manufacturer and airlines using its products falling behind its competitors. Too much may result in an over-extension with, for example, use of immature technologies that do not have the necessary reliability for a safety critical industry or sufficient value to justify the development effort. The multiple requirements associated with cabin design, can be viewed as an area for optimisation, accepting trade-offs between the various parameters. Good design, however, is often defined as developing a concept that resolves the contradictions and takes the solution towards a win-win scenario. Indeed our understanding and practice of design allows for behaviors that enhance design thinking through divergence and convergence, the use of abductive reasoning, experimentation and systems thinking. This paper explores and defines the challenges of designing the aircraft cabin of the future that will deliver on the multiple
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Riveted Lap Joints in Aircraft Fuselage Design, Analysis and Properties
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...
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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.
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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.
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Review of Design Aspects and Challenges of Efficient and Quiet Amphibious Aircraft
D, Rhea P. Liem Ph.
2018-04-01
Apart from the commercial and military aviation sectors, the general aviation (GA) sector is expected to experience a rapid growth, especially in Asia. The increasing economic activities in the region would demand for more efficient and convenient transportation, which would open door to more GA services. This development would require sufficient infrastructure supports, including airports. However, insufficient land area has often imposed limitations in airport development. As such, some areas (e.g., remote islands) are not easily accessible by air. One implication is that travels can only be done via land or water, which might prolong the travel time. This applies to business travels, with the significant increase in business and economic activities, which in turns demands for more efficient and faster mobility. In other cases, this involves some rural areas where the infrastructures are not very well-developed, and where the geographical terrains are too challenging to build a pad for vertical takeoff and landing (VTOL) air vehicles. Under such circumstances, it would be imperative to enable air travels to carry critical logistics such as medical supplies, food, and even sick patients. In this regard, we propose to develop a low-payload, low-altitude amphibious aircraft, which can takeoff and land on both water and land. Aircraft design process is a complex procedure and multidisciplinary in nature, and for amphibious aircraft design we need to consider the two takeoff and landing modes, which imposes further challenges to the design. In this paper we present two preliminary design projects, for two-seater and ten-seater aircraft. To design an efficient and quiet amphibious aircraft, we conduct some experiments on noise shielding mechanisms to reduce the propeller noise. The challenges and resulting designs are briefly discussed in this paper. Amphibious aircraft development will be very relevant to Indonesia, which is the world’s largest archipelago with
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Neural network application to aircraft control system design
Troudet, Terry; Garg, Sanjay; Merrill, Walter C.
1991-01-01
The feasibility of using artificial neural network as control systems for modern, complex aerospace vehicles is investigated via an example aircraft control design study. The problem considered is that of designing a controller for an integrated airframe/propulsion longitudinal dynamics model of a modern fighter aircraft to provide independent control of pitch rate and airspeed responses to pilot command inputs. An explicit model following controller using H infinity control design techniques is first designed to gain insight into the control problem as well as to provide a baseline for evaluation of the neurocontroller. Using the model of the desired dynamics as a command generator, a multilayer feedforward neural network is trained to control the vehicle model within the physical limitations of the actuator dynamics. This is achieved by minimizing an objective function which is a weighted sum of tracking errors and control input commands and rates. To gain insight in the neurocontrol, linearized representations of the nonlinear neurocontroller are analyzed along a commanded trajectory. Linear robustness analysis tools are then applied to the linearized neurocontroller models and to the baseline H infinity based controller. Future areas of research identified to enhance the practical applicability of neural networks to flight control design.
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Neural network application to aircraft control system design
Troudet, Terry; Garg, Sanjay; Merrill, Walter C.
1991-01-01
The feasibility of using artificial neural networks as control systems for modern, complex aerospace vehicles is investigated via an example aircraft control design study. The problem considered is that of designing a controller for an integrated airframe/propulsion longitudinal dynamics model of a modern fighter aircraft to provide independent control of pitch rate and airspeed responses to pilot command inputs. An explicit model following controller using H infinity control design techniques is first designed to gain insight into the control problem as well as to provide a baseline for evaluation of the neurocontroller. Using the model of the desired dynamics as a command generator, a multilayer feedforward neural network is trained to control the vehicle model within the physical limitations of the actuator dynamics. This is achieved by minimizing an objective function which is a weighted sum of tracking errors and control input commands and rates. To gain insight in the neurocontrol, linearized representations of the nonlinear neurocontroller are analyzed along a commanded trajectory. Linear robustness analysis tools are then applied to the linearized neurocontroller models and to the baseline H infinity based controller. Future areas of research are identified to enhance the practical applicability of neural networks to flight control design.
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Application of computational aerodynamics methods to the design and analysis of transport aircraft
Da Costa, A. L.
1978-01-01
The application and validation of several computational aerodynamic methods in the design and analysis of transport aircraft is established. An assessment is made concerning more recently developed methods that solve three-dimensional transonic flow and boundary layers on wings. Capabilities of subsonic aerodynamic methods are demonstrated by several design and analysis efforts. Among the examples cited are the B747 Space Shuttle Carrier Aircraft analysis, nacelle integration for transport aircraft, and winglet optimization. The accuracy and applicability of a new three-dimensional viscous transonic method is demonstrated by comparison of computed results to experimental data
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The Guardian: Preliminary design of a close air support aircraft
Haag, Jonathan; Huber, David; Mcinerney, Kelly; Mulligan, Greg; Pessin, David; Seelos, Michael
1991-01-01
One design is presented of a Close Air Support (CAS) aircraft. It is a canard wing, twin engine, twin vertical tail aircraft that has the capability to cruise at 520 knots. The Guardian contains state of the art flight control systems. Specific highlights of the Guardian include: (1) low cost (the acquisition cost per airplane is $13.6 million for a production of 500 airplanes); (2) low maintenance (it was designed to be easily maintainable in unprepared fields); and (3) high versatility (it can perform a wide range of missions). Along with being a CAS aircraft, it is capable of long ferry missions, battlefield interdiction, maritime attack, and combat rescue. The Guardian is capable of a maximum ferry of 3800 nm, can takeoff in a distance of 1700 ft, land in a ground roll distance of 1644 ft. It has a maximum takeoff weight of 48,753 lbs, and is capable of carrying up to 19,500 lbs of ordinance.
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Revell, J. D.; Balena, F. J.; Koval, L. R.
1980-01-01
The acoustical treatment mass penalties required to achieve an interior noise level of 80 dBA for high speed, fuel efficient propfan-powered aircraft are determined. The prediction method used is based on theory developed for the outer shell dynamics, and a modified approach for add-on noise control element performance. The present synthesis of these methods is supported by experimental data. Three different sized aircraft are studied, including a widebody, a narrowbody and a business sized aircraft. Noise control penalties are calculated for each aircraft for two kinds of noise control designs: add-on designs, where the outer wall structure cannot be changed, and advanced designs where the outer wall stiffness level and the materials usage can be altered. For the add-on designs, the mass penalties range from 1.7 to 2.4 percent of the takeoff gross weight (TOGW) of the various aircraft, similar to preliminary estimates. Results for advanced designs show significant reductions of the mass penalties. For the advanced aluminum designs the penalties are 1.5% of TOGW, and for an all composite aircraft the penalties range from 0.74 to 1.4% of TOGW.
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Method of test signal design for estimating the aircraft aerodynamic parameters
Belokon', S. A.; Zolotukhin, Yu. N.; Filippov, M. N.
2017-07-01
A method of test signal design is proposed for studying the aircraft aerodynamic characteristics with the use of the technology of dynamically scaled free-flight models. Simultaneous excitation of all input channels in a prescribed frequency band by a set of mutually orthogonal signals is applied to increase the efficiency. A modified method of calculating the set of mutually orthogonal sinusoidal signals with a small normalized peak factor is presented. Results of simulating the aircraft motion in the MATLAB/Simulink environment with the use of the developed method of test signal design are reported.
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Aircraft directional stability and vertical tail design: A review of semi-empirical methods
Ciliberti, Danilo; Della Vecchia, Pierluigi; Nicolosi, Fabrizio; De Marco, Agostino
2017-11-01
Aircraft directional stability and control are related to vertical tail design. The safety, performance, and flight qualities of an aircraft also depend on a correct empennage sizing. Specifically, the vertical tail is responsible for the aircraft yaw stability and control. If these characteristics are not well balanced, the entire aircraft design may fail. Stability and control are often evaluated, especially in the preliminary design phase, with semi-empirical methods, which are based on the results of experimental investigations performed in the past decades, and occasionally are merged with data provided by theoretical assumptions. This paper reviews the standard semi-empirical methods usually applied in the estimation of airplane directional stability derivatives in preliminary design, highlighting the advantages and drawbacks of these approaches that were developed from wind tunnel tests performed mainly on fighter airplane configurations of the first decades of the past century, and discussing their applicability on current transport aircraft configurations. Recent investigations made by the authors have shown the limit of these methods, proving the existence of aerodynamic interference effects in sideslip conditions which are not adequately considered in classical formulations. The article continues with a concise review of the numerical methods for aerodynamics and their applicability in aircraft design, highlighting how Reynolds-Averaged Navier-Stokes (RANS) solvers are well-suited to attain reliable results in attached flow conditions, with reasonable computational times. From the results of RANS simulations on a modular model of a representative regional turboprop airplane layout, the authors have developed a modern method to evaluate the vertical tail and fuselage contributions to aircraft directional stability. The investigation on the modular model has permitted an effective analysis of the aerodynamic interference effects by moving, changing, and
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Rommel, Bruce A.
1989-01-01
An overview of the Aeroelastic Design Optimization Program (ADOP) at the Douglas Aircraft Company is given. A pilot test program involving the animation of mode shapes with solid rendering as well as wire frame displays, a complete aircraft model of a high-altitude hypersonic aircraft to test ADOP procedures, a flap model, and an aero-mesh modeler for doublet lattice aerodynamics are discussed.
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The multidisciplinary design optimization of a distributed propulsion blended-wing-body aircraft
Ko, Yan-Yee Andy
The purpose of this study is to examine the multidisciplinary design optimization (MDO) of a distributed propulsion blended-wing-body (BWB) aircraft. The BWB is a hybrid shape resembling a flying wing, placing the payload in the inboard sections of the wing. The distributed propulsion concept involves replacing a small number of large engines with many smaller engines. The distributed propulsion concept considered here ducts part of the engine exhaust to exit out along the trailing edge of the wing. The distributed propulsion concept affects almost every aspect of the BWB design. Methods to model these effects and integrate them into an MDO framework were developed. The most important effect modeled is the impact on the propulsive efficiency. There has been conjecture that there will be an increase in propulsive efficiency when there is blowing out of the trailing edge of a wing. A mathematical formulation was derived to explain this. The formulation showed that the jet 'fills in' the wake behind the body, improving the overall aerodynamic/propulsion system, resulting in an increased propulsive efficiency. The distributed propulsion concept also replaces the conventional elevons with a vectored thrust system for longitudinal control. An extension of Spence's Jet Flap theory was developed to estimate the effects of this vectored thrust system on the aircraft longitudinal control. It was found to provide a reasonable estimate of the control capability of the aircraft. An MDO framework was developed, integrating all the distributed propulsion effects modeled. Using a gradient based optimization algorithm, the distributed propulsion BWB aircraft was optimized and compared with a similarly optimized conventional BWB design. Both designs are for an 800 passenger, 0.85 cruise Mach number and 7000 nmi mission. The MDO results found that the distributed propulsion BWB aircraft has a 4% takeoff gross weight and a 2% fuel weight. Both designs have similar planform shapes
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Welstead, Jason; Crouse, Gilbert L., Jr.
2014-01-01
Empirical sizing guidelines such as tail volume coefficients have long been used in the early aircraft design phases for sizing stabilizers, resulting in conservatively stable aircraft. While successful, this results in increased empty weight, reduced performance, and greater procurement and operational cost relative to an aircraft with optimally sized surfaces. Including flight dynamics in the conceptual design process allows the design to move away from empirical methods while implementing modern control techniques. A challenge of flight dynamics and control is the numerous design variables, which are changing fluidly throughout the conceptual design process, required to evaluate the system response to some disturbance. This research focuses on addressing that challenge not by implementing higher order tools, such as computational fluid dynamics, but instead by linking the lower order tools typically used within the conceptual design process so each discipline feeds into the other. In thisresearch, flight dynamics and control was incorporated into the conceptual design process along with the traditional disciplines of vehicle sizing, weight estimation, aerodynamics, and performance. For the controller, a linear quadratic regulator structure with constant gains has been specified to reduce the user input. Coupling all the disciplines in the conceptual design phase allows the aircraft designer to explore larger design spaces where stabilizers are sized according to dynamic response constraints rather than historical static margin and volume coefficient guidelines.
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Some trends in aircraft design: Structures
Brooks, G. W.
1975-01-01
Trends and programs currently underway on the national scene to improve the structural interface in the aircraft design process are discussed. The National Aeronautics and Space Administration shares a partnership with the educational and industrial community in the development of the tools, the criteria, and the data base essential to produce high-performance and cost-effective vehicles. Several thrusts to build the technology in materials, structural concepts, analytical programs, and integrated design procedures essential for performing the trade-offs required to fashion competitive vehicles are presented. The application of advanced fibrous composites, improved methods for structural analysis, and continued attention to important peripheral problems of aeroelastic and thermal stability are among the topics considered.
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N+3 Aircraft Concept Designs and Trade Studies. Volume 1
Greitzer, E. M.; Bonnefoy, P. A.; DelaRosaBlanco, E.; Dorbian, C. S.; Drela, M.; Hall, D. K.; Hansman, R. J.; Hileman, J. I.; Liebeck, R. H.; Levegren, J.;
2010-01-01
MIT, Aerodyne Research, Aurora Flight Sciences, and Pratt & Whitney have collaborated to address NASA s desire to pursue revolutionary conceptual designs for a subsonic commercial transport that could enter service in the 2035 timeframe. The MIT team brings together multidisciplinary expertise and cutting-edge technologies to determine, in a rigorous and objective manner, the potential for improvements in noise, emissions, and performance for subsonic fixed wing transport aircraft. The collaboration incorporates assessment of the trade space in aerodynamics, propulsion, operations, and structures to ensure that the full spectrum of improvements is identified. Although the analysis focuses on these key areas, the team has taken a system-level approach to find the integrated solutions that offer the best balance in performance enhancements. Based on the trade space analyses and system-level assessment, two aircraft have been identified and carried through conceptual design to show both the in-depth engineering that underpins the benefits envisioned and also the technology paths that need to be followed to enable, within the next 25 years, the development of aircraft three generations ahead in capabilities from those flying today.
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A trade-off analysis design tool. Aircraft interior noise-motion/passenger satisfaction model
Jacobson, I. D.
1977-01-01
A design tool was developed to enhance aircraft passenger satisfaction. The effect of aircraft interior motion and noise on passenger comfort and satisfaction was modelled. Effects of individual aircraft noise sources were accounted for, and the impact of noise on passenger activities and noise levels to safeguard passenger hearing were investigated. The motion noise effect models provide a means for tradeoff analyses between noise and motion variables, and also provide a framework for optimizing noise reduction among noise sources. Data for the models were collected onboard commercial aircraft flights and specially scheduled tests.
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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.
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Design and Evaluation of Nextgen Aircraft Separation Assurance Concepts
Johnson, Walter; Ho, Nhut; Arutyunov, Vladimir; Laue, John-Luke; Wilmoth, Ian
2012-01-01
To support the development and evaluation of future function allocation concepts for separation assurance systems for the Next Generation Air Transportation System, this paper presents the design and human-in-the-loop evaluation of three feasible function allocation concepts that allocate primary aircraft separation assurance responsibilities and workload to: 1) pilots; 2) air traffic controllers (ATC); and 3) automation. The design of these concepts also included rules of the road, separation assurance burdens for aircraft of different equipage levels, and utilization of advanced weather displays paired with advanced conflict detection and resolution automation. Results of the human-in-the-loop simulation show that: a) all the concepts are robust with respect to weather perturbation; b) concept 1 (pilots) had highest throughput, closest to assigned spacing, and fewest violations of speed and altitude restrictions; c) the energy of the aircraft during the descent phase was better managed in concepts 1 and 2 (pilots and ATC) than in concept 3 (automation), in which the situation awareness of pilots and controllers was lowest, and workload of pilots was highest. The paper also discusses further development of these concepts and their augmentation and integration with future air traffic management tools and systems that are being considered for NextGen.
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Analysis of Turbofan Design Options for an Advanced Single-Aisle Transport Aircraft
Guynn, Mark D.; Berton, Jeffrey J.; Fisher, Kenneth L.; Haller, William J.; Tong, Michael T.; Thurman, Douglas R.
2009-01-01
The desire for higher engine efficiency has resulted in the evolution of aircraft gas turbine engines from turbojets, to low bypass ratio, first generation turbofans, to today's high bypass ratio turbofans. It is possible that future designs will continue this trend, leading to very-high or ultra-high bypass ratio (UHB) engines. Although increased bypass ratio has clear benefits in terms of propulsion system metrics such as specific fuel consumption, these benefits may not translate into aircraft system level benefits due to integration penalties. In this study, the design trade space for advanced turbofan engines applied to a single-aisle transport (737/A320 class aircraft) is explored. The benefits of increased bypass ratio and associated enabling technologies such as geared fan drive are found to depend on the primary metrics of interest. For example, bypass ratios at which fuel consumption is minimized may not require geared fan technology. However, geared fan drive does enable higher bypass ratio designs which result in lower noise. Regardless of the engine architecture chosen, the results of this study indicate the potential for the advanced aircraft to realize substantial improvements in fuel efficiency, emissions, and noise compared to the current vehicles in this size class.
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Conceptual/preliminary design study of subsonic v/stol and stovl aircraft derivatives of the S-3A
Kidwell, G. H., Jr.
1981-01-01
A computerized aircraft synthesis program was used to examine the feasibility and capability of a V/STOL aircraft based on the Navy S-3A aircraft. Two major airframe modifications are considered: replacement of the wing, and substitution of deflected thrust turbofan engines similar to the Pegasus engine. Three planform configurations for the all composite wing were investigated: an unconstrained span design, a design with the span constrained to 64 feet, and an unconstrained span oblique wing design. Each design was optimized using the same design variables, and performance and control analyses were performed. The oblique wing configuration was found to have the greatest potential in this application. The mission performance of these V/STOL aircraft compares favorably with that of the CTOL S-3A.
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Analysis and design of hybrid electric regional turboprop aircraft
Voskuijl, M.; van Bogaert, J.; Gangoli Rao, A.
2017-01-01
The potential environmental benefits of hybrid electric regional turboprop aircraft in terms of fuel consumption are investigated. Lithium–air batteries are used as energy source in combination with conventional fuel. A validated design and analysis framework is extended with sizing and analysis
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INFORMATION-ENERGY METHODOLOGY OF THE AIRCRAFT WITH ELECTRIC PROPULSION ENERGY COMPLEX DESIGN
Directory of Open Access Journals (Sweden)
Boris Vladimirovich Zhmurov
2017-01-01
Full Text Available Research in the field of aircraft development shows that from the point of view of sustainability and energy effi- ciency the most acceptable approach is the transition to all-electric aircraft (AEC. Electrification is aimed primarily on the aircraft most energy-intensive elements efficiency enhancing. Primarily these are power plant and air conditioning system. The actual problem discussed in this article is the development of methodology for the design of aircraft power complex with electric propulsion. The electric power plant literally extends the concept of aircraft power complex. The article con- siders two-level energy-informational design technology of the aircraft power complex. On the energetic level, the energy flows are optimized, and on the information level, the control laws that ensure restrictions compliance and loss minimiza- tion for a given level of entire system reliability are synthesized. From the point of view of sustainability and energy effi- ciency, the most acceptable is the transition to AEC. The proposed information-energy technique provides an opportunity to develop electric and hybrid aircraft with optimal weight and size and energy characteristics due to: electricity consump- tion timeline optimization through the redistribution of electric end users switch on moments, which provides a more uni- form power mode, allowing the same set of electric users to reduce generator rated power, and as a result reduce the flight weight; manage a distributed system of electricity generation that provides the ability to use diverse energy sources; faul tsafety management based on rapid changes in the power network topology; energy recovery control; the sources, convert- ers and users (input circuit and power network real-time diagnostic operations.
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Design of the crashworthy structure of an urban aircraft
Directory of Open Access Journals (Sweden)
Shang Bairong
2017-01-01
Full Text Available With the development of general aviation, the urban aircraft is around the corner. The urban aircraft with composite is considered as an ultralight vehicle and the crashworthiness is of vital importance for such an ultralight aircraft. Composites are being widely and increasingly used in the aerospace industry because of their advantages that include the high specific strength and stiffness over traditional metallic materials. Besides, composites have the potential for absorbing the energy in a crash event. The crashworthiness of the cockpit section is analyzed in this paper and some modifications in the subfloor have been made to improve the survivability of the pilot. Advances in commercial softwares have enabled engineers to simulate crash events. The three-dimensional structure model is established by use of CATIA software and the crash process is simulated by MSC/DYTRAN. By comparing the crashworthiness of composite structures, reliable basis is provided for the design of a safe and sound structure.
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Boughari, Yamina
New methodologies have been developed to optimize the integration, testing and certification of flight control systems, an expensive process in the aerospace industry. This thesis investigates the stability of the Cessna Citation X aircraft without control, and then optimizes two different flight controllers from design to validation. The aircraft's model was obtained from the data provided by the Research Aircraft Flight Simulator (RAFS) of the Cessna Citation business aircraft. To increase the stability and control of aircraft systems, optimizations of two different flight control designs were performed: 1) the Linear Quadratic Regulation and the Proportional Integral controllers were optimized using the Differential Evolution algorithm and the level 1 handling qualities as the objective function. The results were validated for the linear and nonlinear aircraft models, and some of the clearance criteria were investigated; and 2) the Hinfinity control method was applied on the stability and control augmentation systems. To minimize the time required for flight control design and its validation, an optimization of the controllers design was performed using the Differential Evolution (DE), and the Genetic algorithms (GA). The DE algorithm proved to be more efficient than the GA. New tools for visualization of the linear validation process were also developed to reduce the time required for the flight controller assessment. Matlab software was used to validate the different optimization algorithms' results. Research platforms of the aircraft's linear and nonlinear models were developed, and compared with the results of flight tests performed on the Research Aircraft Flight Simulator. Some of the clearance criteria of the optimized H-infinity flight controller were evaluated, including its linear stability, eigenvalues, and handling qualities criteria. Nonlinear simulations of the maneuvers criteria were also investigated during this research to assess the Cessna
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Continuous Biometric Authentication for Authorized Aircraft Personnel: A Proposed Design
National Research Council Canada - National Science Library
Carrillo, Cassandra
2003-01-01
.... The primary goal of this thesis is to propose a hypothetical design for the use of a non- intrusive mechanism on the flight deck of an aircraft to provide continuous or periodic authentication...
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Goodrich, Kenneth H.; Flemisch, Frank O.; Schutte, Paul C.; Williams, Ralph A.
2006-01-01
Driven by increased safety, efficiency, and airspace capacity, automation is playing an increasing role in aircraft operations. As aircraft become increasingly able to autonomously respond to a range of situations with performance surpassing human operators, we are compelled to look for new methods that help us understand their use and guide their design using new forms of automation and interaction. We propose a novel design metaphor to aid the conceptualization, design, and operation of highly-automated aircraft. Design metaphors transfer meaning from common experiences to less familiar applications or functions. A notable example is the "Desktop metaphor" for manipulating files on a computer. This paper describes a metaphor for highly automated vehicles known as the H-metaphor and a specific embodiment of the metaphor known as the H-mode as applied to aircraft. The fundamentals of the H-metaphor are reviewed followed by an overview of an exploratory usability study investigating human-automation interaction issues for a simple H-mode implementation. The envisioned application of the H-mode concept to aircraft is then described as are two planned evaluations.
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An Indispensable Ingredient: Flight Research and Aircraft Design
Gorn, Michael H.
2003-01-01
Flight research-the art of flying actual vehicles in the atmosphere in order to collect data about their behavior-has played a historic and decisive role in the design of aircraft. Naturally, wind tunnel experiments, computational fluid dynamics, and mathematical analyses all informed the judgments of the individuals who conceived of new aircraft. But flight research has offered moments of realization found in no other method. Engineer Dale Reed and research pilot Milt Thompson experienced one such epiphany on March 1, 1963, at the National Aeronautics and Space Administration s Dryden Flight Research Center in Edwards, California. On that date, Thompson sat in the cockpit of a small, simple, gumdrop-shaped aircraft known as the M2-F1, lashed by a long towline to a late-model Pontiac Catalina. As the Pontiac raced across Rogers Dry Lake, it eventually gained enough speed to make the M2-F1 airborne. Thompson braced himself for the world s first flight in a vehicle of its kind, called a lifting body because of its high lift-to-drag ratio. Reed later recounted what he saw:
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Distributed Electric Propulsion Aircraft Comprehensive Analysis and Design Tool, Phase I
National Aeronautics and Space Administration — The solicitation seeks innovative approaches in designing and analyzing Distributed Electric Propulsion (DEP) aircraft to support ARMD's Strategic Thrust #3...
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Pavel, Marilena D.; Masarati, Pierangelo; Gennaretti, Massimo; Jump, Michael; Zaichik, Larisa; Dang-Vu, Binh; Lu, Linghai; Yilmaz, Deniz; Quaranta, Giuseppe; Ionita, Achim; Serafini, Jacopo
2015-07-01
Understanding, predicting and supressing the inadvertent aircraft oscillations caused by Aircraft/Rotorcraft Pilot Couplings (A/RPC) is a challenging problem for designers. These are potential instabilities that arise from the effort of controlling aircraft with high response actuation systems. The present paper reviews, updates and discusses desirable practices to be used during the design process for unmasking A/RPC phenomena. These practices are stemming from the European Commission project ARISTOTEL Aircraft and Rotorcraft Pilot Couplings - Tools and Techniques for Alleviation and Detection (2010-2013) and are mainly related to aerodynamic and structural modelling of the aircraft/rotorcraft, pilot modelling and A/RPC prediction criteria. The paper proposes new methodologies for precluding adverse A/RPCs events taking into account the aeroelasticity of the structure and pilot biodynamic interaction. It is demonstrated that high-frequency accelerations due to structural elasticity cause negative effects on pilot control, since they lead to involuntary body and limb-manipulator system displacements and interfere with pilot's deliberate control activity (biodynamic interaction) and, finally, worsen handling quality ratings.
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Davendralingam, Navindran
Conceptual design of aircraft and the airline network (routes) on which aircraft fly on are inextricably linked to passenger driven demand. Many factors influence passenger demand for various Origin-Destination (O-D) city pairs including demographics, geographic location, seasonality, socio-economic factors and naturally, the operations of directly competing airlines. The expansion of airline operations involves the identificaion of appropriate aircraft to meet projected future demand. The decisions made in incorporating and subsequently allocating these new aircraft to serve air travel demand affects the inherent risk and profit potential as predicted through the airline revenue management systems. Competition between airlines then translates to latent passenger observations of the routes served between OD pairs and ticket pricing---this in effect reflexively drives future states of demand. This thesis addresses the integrated nature of aircraft design, airline operations and passenger demand, in order to maximize future expected profits as new aircraft are brought into service. The goal of this research is to develop an approach that utilizes aircraft design, airline network design and passenger demand as a unified framework to provide better integrated design solutions in order to maximize expexted profits of an airline. This is investigated through two approaches. The first is a static model that poses the concurrent engineering paradigm above as an investment portfolio problem. Modern financial portfolio optimization techniques are used to leverage risk of serving future projected demand using a 'yet to be introduced' aircraft against potentially generated future profits. Robust optimization methodologies are incorporated to mitigate model sensitivity and address estimation risks associated with such optimization techniques. The second extends the portfolio approach to include dynamic effects of an airline's operations. A dynamic programming approach is
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Analysis and design of insulation systems for LH2-fueled aircraft
Cunnington, G. R., Jr.
1979-01-01
An analytical program was conducted to evaluate the performance of 15 potential insulations for the fuel tanks of a subsonic LH2-fueled transport aircraft intended for airline service in the 1990-1995 time period. As a result, two candidate insulation systems are proposed for subsonic transport aircraft applications. Both candidates are judged to be the optimum available and should meet the design requirements. However, because of the long-life cyclic nature of the application and the cost sensitivity of airline operations, an experimental tank/insulation development or proof-of-concept program is recommended. This program should be carried out with a nearly full-scale system which would be subjected to the cyclic thermal and mechanical inputs anticipated in aircraft service.
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Aircraft-crash-protected roof design for the European SBWR
International Nuclear Information System (INIS)
Posta, B.A.; Kadar, I.; Rao, A.S.
1995-01-01
The European utility requirement document (EURD) places significant emphasis on aircraft crash protection of the reactor building - Alternative concepts were evaluated for protecting the dry-well head and the fuel pool from the effect of the spalling concrete for the General Electric Company's European simplified boiling water reactor (ESBWR) designs
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Design and Evaluation of a Wireless Sensor Network Based Aircraft Strength Testing System
Wu, Jian; Yuan, Shenfang; Zhou, Genyuan; Ji, Sai; Wang, Zilong; Wang, Yang
2009-01-01
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. PMID:22408521
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Design and evaluation of a wireless sensor network based aircraft strength testing system.
Wu, Jian; Yuan, Shenfang; Zhou, Genyuan; Ji, Sai; Wang, Zilong; Wang, Yang
2009-01-01
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.
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Energy conservation aircraft design and operational procedures
Energy Technology Data Exchange (ETDEWEB)
Poisson-Quinton, P.
1978-01-01
The paper reviews studies associated with improved fuel efficiency. Several aircraft design concepts are described including: (1) increases in aerodynamic efficiency through decreased friction drag, parasitic drag, and drag due to lift, (2) structural efficiency and the implementation of composite materials, (3) active control technology, (4) the optimization of airframe-engine integration, and (5) VTOL and STOL concepts. Consideration is also given to operational procedures associated with flight management, terminal-area operations, and the influence of environmental noise constraints on fuel economy.
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Creative thinking of design and redesign on SEAT aircraft cabin testbed: a case study
Tan, C.F.; Chen, W.; Rauterberg, G.W.M.
2009-01-01
this paper, the intuition approach in the design and redesign of the environmental friendly innovative aircraft cabin simulator is presented.. The aircraft cabin simulator is a testbed that used for European Project SEAT (Smart tEchnologies for Stress free Air Travel). The SEAT project aims to
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Automatic Flight Control System Design of Level Change Mode for a Large Aircraft
Directory of Open Access Journals (Sweden)
Huajun Gong
2013-02-01
Full Text Available The level change mode is an essential part of large civil aircraft automatic flight control systems. In cruise, with the decrease of the plane's weight caused by fuel consumption and the influence of bad weather, such as thunderstorms, the level change mode is required to solve this problem. This work establishes a nonlinear model of large aircraft, takes level changed from 9500m to 10100m as an example to design control laws for the level change mode in cruise. The classical engineering method is used to design longitudinal and lateral control laws synthetically. The flight qualities are considered in the design process. Simulation results indicate the control laws can meet design requirements and have a good anti-gust performance.
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Sakata, I. F.; Davis, G. W.
1975-01-01
The materials and advanced producibility methods that offer potential structural mass savings in the design of the primary structure for a supersonic cruise aircraft are identified and reported. A summary of the materials and fabrication techniques selected for this analytical effort is presented. Both metallic and composite material systems were selected for application to a near-term start-of-design technology aircraft. Selective reinforcement of the basic metallic structure was considered as the appropriate level of composite application for the near-term design.
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Applying reliability analysis to design electric power systems for More-electric aircraft
Zhang, Baozhu
The More-Electric Aircraft (MEA) is a type of aircraft that replaces conventional hydraulic and pneumatic systems with electrically powered components. These changes have significantly challenged the aircraft electric power system design. This thesis investigates how reliability analysis can be applied to automatically generate system topologies for the MEA electric power system. We first use a traditional method of reliability block diagrams to analyze the reliability level on different system topologies. We next propose a new methodology in which system topologies, constrained by a set reliability level, are automatically generated. The path-set method is used for analysis. Finally, we interface these sets of system topologies with control synthesis tools to automatically create correct-by-construction control logic for the electric power system.
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Conceptual design for a laminar-flying-wing aircraft
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
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Modeling and Design Analysis Methodology for Tailoring of Aircraft Structures with Composites
Rehfield, Lawrence W.
2004-01-01
Composite materials provide design flexibility in that fiber placement and orientation can be specified and a variety of material forms and manufacturing processes are available. It is possible, therefore, to 'tailor' the structure to a high degree in order to meet specific design requirements in an optimum manner. Common industrial practices, however, have limited the choices designers make. One of the reasons for this is that there is a dearth of conceptual/preliminary design analysis tools specifically devoted to identifying structural concepts for composite airframe structures. Large scale finite element simulations are not suitable for such purposes. The present project has been devoted to creating modeling and design analysis methodology for use in the tailoring process of aircraft structures. Emphasis has been given to creating bend-twist elastic coupling in high aspect ratio wings or other lifting surfaces. The direction of our work was in concert with the overall NASA effort Twenty- First Century Aircraft Technology (TCAT). A multi-disciplinary team was assembled by Dr. Damodar Ambur to work on wing technology, which included our project.
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150 Passenger Commercial Aircraft
Bucovsky, Adrian; Romli, Fairuz I.; Rupp, Jessica
2002-01-01
It has been projected that the need for a short-range mid-sized, aircraft is increasing. The future strategy to decrease long-haul flights will increase the demand for short-haul flights. Since passengers prefer to meet their destinations quickly, airlines will increase the frequency of flights, which will reduce the passenger load on the aircraft. If a point-to-point flight is not possible, passengers will prefer only a one-stop short connecting flight to their final destination. A 150-passenger aircraft is an ideal vehicle for these situations. It is mid-sized aircraft and has a range of 3000 nautical miles. This type of aircraft would market U.S. domestic flights or inter-European flight routes. The objective of the design of the 150-passenger aircraft is to minimize fuel consumption. The configuration of the aircraft must be optimized. This aircraft must meet CO2 and NOx emissions standards with minimal acquisition price and operating costs. This report contains all the work that has been performed for the completion of the design of a 150 passenger commercial aircraft. The methodology used is the Technology Identification, Evaluation, and Selection (TIES) developed at Georgia Tech Aerospace Systems Design laboratory (ASDL). This is an eight-step conceptual design process to evaluate the probability of meeting the design constraints. This methodology also allows for the evaluation of new technologies to be implemented into the design. The TIES process begins with defining the problem with a need established and a market targeted. With the customer requirements set and the target values established, a baseline concept is created. Next, the design space is explored to determine the feasibility and viability of the baseline aircraft configuration. If the design is neither feasible nor viable, new technologies can be implemented to open up the feasible design space and allow for a plausible solution. After the new technologies are identified, they must be evaluated
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Improving aircraft conceptual design - A PHIGS interactive graphics interface for ACSYNT
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.
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Method of transition from 3D model to its ontological representation in aircraft design process
Govorkov, A. S.; Zhilyaev, A. S.; Fokin, I. V.
2018-05-01
This paper proposes the method of transition from a 3D model to its ontological representation and describes its usage in the aircraft design process. The problems of design for manufacturability and design automation are also discussed. The introduced method is to aim to ease the process of data exchange between important aircraft design phases, namely engineering and design control. The method is also intended to increase design speed and 3D model customizability. This requires careful selection of the complex systems (CAD / CAM / CAE / PDM), providing the basis for the integration of design and technological preparation of production and more fully take into account the characteristics of products and processes for their manufacture. It is important to solve this problem, as investment in the automation define the company's competitiveness in the years ahead.
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Directory of Open Access Journals (Sweden)
J.-K. Mueller
2018-01-01
Full Text Available Active high-lift systems of future civil aircraft allow noise reduction and the use of shorter runways. Powering high-lift systems electrically have a strong impact on the design requirements for the electrical power supply of the aircraft. The active high-lift system of the reference aircraft design considered in this paper consists of a flexible leading-edge device together with a combination of boundary-layer suction and Coanda-jet blowing. Electrically driven compressors distributed along the aircraft wings provide the required mass flow of pressurized air. Their additional loads significantly increase the electric power demand during take-off and landing, which is commonly provided by electric generators attached to the aircraft engines. The focus of the present study is a feasibility assessment of alternative electric power supply concepts to unburden or eliminate the generator coupled to the aircraft engine. For this purpose, two different concepts using either fuel cells or batteries are outlined and evaluated in terms of weight, efficiency, and technology availability. The most promising, but least developed alternative to the engine-powered electric generator is the usage of fuel cells. The advantages are high power density and short refueling time, compared to the battery storage concept.
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Constructal Theory and Aeroelastic Design of Flexible Flying Wing Aircraft
Directory of Open Access Journals (Sweden)
Pezhman Mardanpour
2017-07-01
Full Text Available The aeroelastic behavior of high-aspect-ratio very flexible flying wing is highly affected by the geometric nonlinearities of the aircraft structure. This paper reviews the findings on how these nonlinearities influence the structural and flight dynamics, and it shows that the aeroelastic flight envelope could significantly be extended with proper choices of design parameters such as engine placement. Moreover, in order to investigate the physics behind the effects of design parameters, constructal theory of design is reviewed. The constructal theory advances the philosophy of design as science, it states that the better structural design emerges when stress flow strangulation is avoided. Furthermore, it shows that airplanes, through their evolution, have obeyed theoretical allometric rules that unite their designs.
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A Generic Inner-Loop Control Law Structure for Six-Degree-of-Freedom Conceptual Aircraft Design
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.
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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.
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Conceptual Design of a Small Hybrid Unmanned Aircraft System
Directory of Open Access Journals (Sweden)
Umberto Papa
2017-01-01
Full Text Available UAS (Unmanned Aircraft System technologies are today extremely required in various fields of interest, from military to civil (search and rescue, environmental surveillance and monitoring, and entertainment. Besides safety and legislative issues, the main obstacle to civilian applications of UAS systems is the short time of flight (endurance, which depends on the equipped power system (battery pack and the flight mission (low/high speed or altitude. Long flight duration is fundamental, especially with tasks that require hovering capability (e.g., river flow monitoring, earthquakes, devastated areas, city traffic monitoring, and archeological sites inspection. This work presents the conceptual design of a Hybrid Unmanned Aircraft System (HUAS, merging a commercial off-the-shelf quadrotor and a balloon in order to obtain a good compromise between endurance and weight. The mathematical models for weights estimation and balloon static performance analysis are presented, together with experimental results in different testing scenarios and complex environments, which show 50% improvement of the flight duration.
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A design study for a simple-to-fly, constant attitude light aircraft
Smetana, F. O.; Humphreys, D. E.; Montoya, R. J.; Rickard, W. W.; Wilkinson, I. E.
1973-01-01
The activities during a four-year study by doctoral students to evolve in detail a design for a simple-to-fly, constant attitude light airplane are described. The study indicated that such aircraft could materially reduce the hazards to light airplane occupants which arise from the high pilot work load and poor visibility that occur during landing. Preliminary cost studies indicate that in volume production this system would increase the cost of the aircraft in roughly the same fashion that automatic transmission, power steering, power brakes, and cruise control increase the cost of a compact car.
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A Generic Approach to Analyze the Impact of a Future Aircraft Design on the Boarding Process
Directory of Open Access Journals (Sweden)
Bekir Yildiz
2018-01-01
Full Text Available The turnaround process constitutes an important part of the air transportation system. Airports often represent bottlenecks in air traffic management (ATM, thus operations related to the preparation of the aircraft for the next flight leg have to be executed smoothly and in a timely manner. The ATM significantly depends on a reliable turnaround process. Future paradigm changes with respect to airplane energy sources, aircraft design or propulsion concepts will also influence the airport layout. As a consequence, operational processes associated with the turnaround will be affected. Airlines aim for efficient and timely turnaround operations that are correlated with higher profits. This case study discusses an approach to investigate a new aircraft design with respect to the implications on the turnaround. The boarding process, as part of the turnaround, serves as an example to evaluate the consequences of new design concepts. This study is part of an interdisciplinary research to investigate future energy, propulsion and designs concepts and their implications on the whole ATM system. Due to these new concepts, several processes of the turnaround will be affected. For example, new energy storage concepts will influence the fueling process on the aircraft itself or might lead to a new infrastructure at the airport. This paper aims to evaluate the applied methodology in the case of a new boarding process, due to a new aircraft design, by means of a generic example. An agent-based boarding simulation is applied to assess passenger behavior during boarding, particularly with regard to cabin layout and seat configuration. The results of the generic boarding simulation are integrated into a simplified, deterministic and generic simulation of the turnaround process. This was done to assess the proposed framework for future investigations which on the one hand address the ATM system holistically and on the other, incorporate additional or adapted
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Exploring the design of a lightweight, sustainable and comfortable aircraft seat.
Kokorikou, A; Vink, P; de Pauw, I C; Braca, A
2016-07-19
Making a lightweight seat that is also comfortable can be contradictory because usually comfort improvement means adding a feature (e.g. headrest, adjustable lumbar support, movable armrests, integrated massage systems, etc.), which makes seats heavier. This paper explores the design of an economy class aircraft seat that aims to be lightweight, comfortable and sustainable. Theory about comfort in seats, ergonomics, lightweight design, Biomimicry and Cradle to cradle was studied and resulted in a list of requirements that the new seat should satisfy. The design process resulted in a new seat that is 36% lighter than the reference seat, which showed that a significant weight reduction can be achieved. This was completed by re-designing the backrest and seat pan and integrating their functions into a reduced number of parts. Apart from the weight reduction that helps in reducing the airplane's environmental impact, the seat also satisfies most of the other sustainability requirements such as the use of recyclable materials, design for disassembly, easy to repair. A user test compared the new seat with a premium economy class aircraft seat and the level of comfort was similar. Strong points of the new design were identified such as the lumbar support and the cushioning material, as well as shortcomings on which the seat needs to be improved, like the seat pan length and the first impression. Long term comfort tests are still needed as the seat is meant for long-haul flights.
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A Conceptual Design and Optimization Method for Blended-Wing-Body Aircraft
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
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A systematic method of smooth switching LPV controllers design for a morphing aircraft
Directory of Open Access Journals (Sweden)
Jiang Weilai
2015-12-01
Full Text Available This paper is concerned with a systematic method of smooth switching linear parameter-varying (LPV controllers design for a morphing aircraft with a variable wing sweep angle. The morphing aircraft is modeled as an LPV system, whose scheduling parameter is the variation rate of the wing sweep angle. By dividing the scheduling parameter set into subsets with overlaps, output feedback controllers which consider smooth switching are designed and the controllers in overlapped subsets are interpolated from two adjacent subsets. A switching law without constraint on the average dwell time is obtained which makes the conclusion less conservative. Furthermore, a systematic algorithm is developed to improve the efficiency of the controllers design process. The parameter set is divided into the fewest subsets on the premise that the closed-loop system has a desired performance. Simulation results demonstrate the effectiveness of this approach.
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Fuel characteristics pertinent to the design of aircraft fuel systems
Barnett, Henry C; Hibbard, R R
1953-01-01
Because of the importance of fuel properties in design of aircraft fuel systems the present report has been prepared to provide information on the characteristics of current jet fuels. In addition to information on fuel properties, discussions are presented on fuel specifications, the variations among fuels supplied under a given specification, fuel composition, and the pertinence of fuel composition and physical properties to fuel system design. In some instances the influence of variables such as pressure and temperature on physical properties is indicated. References are cited to provide fuel system designers with sources of information containing more detail than is practicable in the present report.
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Landing Gear Integration in Aircraft Conceptual Design. Revision
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.
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Modeling Materials: Design for Planetary Entry, Electric Aircraft, and Beyond
Thompson, Alexander; Lawson, John W.
2014-01-01
NASA missions push the limits of what is possible. The development of high-performance materials must keep pace with the agency's demanding, cutting-edge applications. Researchers at NASA's Ames Research Center are performing multiscale computational modeling to accelerate development times and further the design of next-generation aerospace materials. Multiscale modeling combines several computationally intensive techniques ranging from the atomic level to the macroscale, passing output from one level as input to the next level. These methods are applicable to a wide variety of materials systems. For example: (a) Ultra-high-temperature ceramics for hypersonic aircraft-we utilized the full range of multiscale modeling to characterize thermal protection materials for faster, safer air- and spacecraft, (b) Planetary entry heat shields for space vehicles-we computed thermal and mechanical properties of ablative composites by combining several methods, from atomistic simulations to macroscale computations, (c) Advanced batteries for electric aircraft-we performed large-scale molecular dynamics simulations of advanced electrolytes for ultra-high-energy capacity batteries to enable long-distance electric aircraft service; and (d) Shape-memory alloys for high-efficiency aircraft-we used high-fidelity electronic structure calculations to determine phase diagrams in shape-memory transformations. Advances in high-performance computing have been critical to the development of multiscale materials modeling. We used nearly one million processor hours on NASA's Pleiades supercomputer to characterize electrolytes with a fidelity that would be otherwise impossible. For this and other projects, Pleiades enables us to push the physics and accuracy of our calculations to new levels.
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Design and evaluation of aircraft heat source systems for use with high-freezing point fuels
Pasion, A. J.
1979-01-01
The objectives were the design, performance and economic analyses of practical aircraft fuel heating systems that would permit the use of high freezing-point fuels on long-range aircraft. Two hypothetical hydrocarbon fuels with freezing points of -29 C and -18 C were used to represent the variation from current day jet fuels. A Boeing 747-200 with JT9D-7/7A engines was used as the baseline aircraft. A 9300 Km mission was used as the mission length from which the heat requirements to maintain the fuel above its freezing point was based.
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An overview of the Douglas Aircraft Company Aeroelastic Design Optimization Program (ADOP)
Dodd, Alan J.
1989-01-01
From a program manager's viewpoint, the history, scope and architecture of a major structural design program at Douglas Aircraft Company called Aeroelastic Design Optimization Program (ADOP) are described. ADOP was originally intended for the rapid, accurate, cost-effective evaluation of relatively small structural models at the advanced design level, resulting in improved proposal competitiveness and avoiding many costly changes later in the design cycle. Before release of the initial version in November 1987, however, the program was expanded to handle very large production-type analyses.
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Advanced piloted aircraft flight control system design methodology. Volume 1: Knowledge base
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.
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Design of aircraft cabin testbed for stress free air travel experiment
Tan, C.F.; Chen, W.; Rauterberg, G.W.M.
2009-01-01
The paper presents an aircraft cabin testbed that is designed and built for the stress free air travel experiment. The project is funded by European Union in the aim of improving air travel comfort during long haul flight. The testbed is used to test and validate the adaptive system that is capable
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On Obtaining Design Allowables for Adhesives Used in the Bonded-Composite Repair of Aircraft
National Research Council Canada - National Science Library
Chalkley, Peter
1998-01-01
A technique is documented, along with its experimental validation, for obtaining engineering-standard design allowables for structural adhesives used in the bonded/composite repair of aircraft structure...
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Essentials of aircraft armaments
Kaushik, Mrinal
2017-01-01
This book aims to provide a complete exposure about armaments from their design to launch from the combat aircraft. The book details modern ammunition and their tactical roles in warfare. The proposed book discusses aerodynamics, propulsion, structural as well as navigation, control, and guidance of aircraft armament. It also introduces the various types of ammunition developed by different countries and their changing trends. The book imparts knowledge in the field of design, and development of aircraft armaments to aerospace engineers and covers the role of the United Nations in peacekeeping and disarmament. The book will be very useful to researchers, students, and professionals working in design and manufacturing of aircraft armaments. The book will also serve air force and naval aspirants, and those interested in working on defence research and developments organizations. .
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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.
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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
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Directory of Open Access Journals (Sweden)
Wang Hongyu
2018-01-01
Full Text Available This paper presents the design of a symmetrical quad-rotor biplane tail-sitter VTOL UAV (Vertical Take-off and Landing Unmanned Aerial Vehicle which is composed of four rotors and two symmetrically mounted fixed wings. This aircraft achieves high accuracy in the attitude control and smooth flight mode transition with four rotors rather than the conventional VTOL UAVs using control surfaces. The proposal of angled rotor mounting is adopted to address the issue of insufficient yaw control authority. The layout of symmetrically mounted fixed wings makes the aircraft have capability of rapid bidirectional flight mode transition to improve maneuverability. To validate the performance of the aircraft, simulation and flight experiments are both implemented. These results show that the aircraft has a rapid yaw response under condition of the stable attitude control. In comparative experiment, it is shown that the aircraft is more flexible than other similar configuration of aircrafts. This symmetrical quad-rotor biplane tail-sitter VTOL UAV will have a wide range of potential applications in the military and civilian areas due to its superior performance..
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Tan, C.F.; Chen, W.; Rauterberg, G.W.M.
2009-01-01
In this paper, a study of the concurrent engineering design for the environmental friendly low cost aircraft cabin simulator is presented. The study describes the used of concurrent design technique in the design activity. The simulator is a testbed that was designed and built for research on
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Sobieszczanski-Sobieski, Jaroslaw
1988-01-01
Optimization by decomposition, complex system sensitivity analysis, and a rapid growth of disciplinary sensitivity analysis are some of the recent developments that hold promise of a quantum jump in the support engineers receive from computers in the quantitative aspects of design. Review of the salient points of these techniques is given and illustrated by examples from aircraft design as a process that combines the best of human intellect and computer power to manipulate data.
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1989-01-01
The major objective of this project was to design an aircraft for use in the California Corridor in the year 2010. The design process, completed by students in a senior design class at California Polytechnic State University, San Luis Obispo, used a Class 1 airplane design analysis from Jan Roskam's Airplane Design. The California Condor (CC-38), a 38 passenger, 400 mph aircraft, was designed to meet the needs of tomorrow's passengers while conforming to the California Corridor's restrictions. Assumptions were made using today's technology with forecasts into 21st Century technology. Doubling today's commuter aircraft passenger capacity, travelling at Mach .57 with improved cruise efficiencies of over 10 percent, with the ability to land within field lengths of 4000 feet, are the CC-38's strongest points. The California Condor has a very promising future in helping to relieve the air traffic and airport congestion in the 21st Century.
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Integrating Cloud-Computing-Specific Model into Aircraft Design
Zhimin, Tian; Qi, Lin; Guangwen, Yang
Cloud Computing is becoming increasingly relevant, as it will enable companies involved in spreading this technology to open the door to Web 3.0. In the paper, the new categories of services introduced will slowly replace many types of computational resources currently used. In this perspective, grid computing, the basic element for the large scale supply of cloud services, will play a fundamental role in defining how those services will be provided. The paper tries to integrate cloud computing specific model into aircraft design. This work has acquired good results in sharing licenses of large scale and expensive software, such as CFD (Computational Fluid Dynamics), UG, CATIA, and so on.
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Analyses of Aircraft Responses to Atmospheric Turbulence
Van Staveren, W.H.J.J.
2003-01-01
The response of aircraft to stochastic atmospheric turbulence plays an important role in aircraft-design (load calculations), Flight Control System (FCS) design and flight-simulation (handling qualities research and pilot training). In order to simulate these aircraft responses, an accurate
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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).
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The design of nuclear power plants in the Federal Republic of Germany as regards aircraft accidents
International Nuclear Information System (INIS)
Anon.
1978-01-01
On the basis of investigation results of aircraft crashes for the Federal territory and site assessment data of the Ministry of the Interior, air traffic does not present a notable hazard for a nuclear power plant. As a precautionary measure for reducing the remaining risk, design requirements for LWRs were developed which, independently of existing aircraft types, contain mainly an abstract predetermination of an idealized impact load - time diagramme. (HP) [de
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Denieul , Yann; Alazard , Daniel; Bordeneuve-Guibé , Joël; Toussaint , Clément; Taquin , Gilles
2015-01-01
International audience; In this paper the problem of integrated design and control for a civil blended wing-body aircraft is addressed. Indeed this configuration faces remarkable challenges relatedto handling qualities: namely the aircraft configuration in this study features a strong longitudinal instability for some specific flight points. Moreover it may lack control efficiency despite large and redundant movables. Stabilizing such a configuration may then lead to high control surfaces rat...
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Aircraft Crash Survival Design Guide. Volume 5. Aircraft Postcrash Survival
1980-01-01
neck Access door toprille capm enrFuel tank Figue 3. Fangblefiler eckinsalgbelati n. A-j L)n wal Aircraft skin Frangible filler neck Failure plane...This is because a number of major assumptions must be made in the extrapolation: the smoke generated is uniformly distri- buted and is independent
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Principles for Aircraft Energy Mapping
Berg, Frederick T N
2013-01-01
An increasing emphasis on energy eciency in aircraft systems has in recentyears led to greater interest in integrated design and optimisation withinthe industry. New tools are needed to understand, compare and manage energyuse of an aircraft throughout its design and operation. This thesis describes a new methodology to meet this need: aircraft exergy mapping.The choice of exergy, a 2nd law metric, to describe the energy ows is fundamental to the methodology, providing numerous advantages ove...
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Small transport aircraft technology
Williams, L. J.
1983-01-01
Information on commuter airline trends and aircraft developments is provided to upgrade the preliminary findings of a NASA-formed small transport aircraft technology (STAT) team, established to determine whether the agency's research and development programs could help commuter aircraft manufacturers solve technical problems related to passenger acceptance and use of 19- to 50-passenger aircraft. The results and conclusions of the full set of completed STAT studies are presented. These studies were performed by five airplane manufacturers, five engine manufacturers, and two propeller manufacturers. Those portions of NASA's overall aeronautics research and development programs which are applicable to commuter aircraft design are summarized. Areas of technology that might beneficially be expanded or initiated to aid the US commuter aircraft manufacturers in the evolution of improved aircraft for the market are suggested.
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Aerodynamic study, design and construction of a Blended Wing Body (BWB) Unmanned Aircraft (UA)
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...
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Design of adaptive switching control for hypersonic aircraft
Directory of Open Access Journals (Sweden)
Xin Jiao
2015-10-01
Full Text Available This article proposes a novel adaptive switching control of hypersonic aircraft based on type-2 Takagi–Sugeno–Kang fuzzy sliding mode control and focuses on the problem of stability and smoothness in the switching process. This method uses full-state feedback to linearize the nonlinear model of hypersonic aircraft. Combining the interval type-2 Takagi–Sugeno–Kang fuzzy approach with sliding mode control keeps the adaptive switching process stable and smooth. For rapid stabilization of the system, the adaptive laws use a direct constructive Lyapunov analysis together with an established type-2 Takagi–Sugeno–Kang fuzzy logic system. Simulation results indicate that the proposed control scheme can maintain the stability and smoothness of switching process for the hypersonic aircraft.
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Application of modern control design methodology to oblique wing research aircraft
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.
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Design of heavy lift cargo aircraft
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...
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Acoustical design economic trade off for transport aircraft
Benito, A.
The effects of ICAO fixed certification limits and local ordinances on acoustic emissions from jets on commercial transport aircraft and costs of operations are explored. The regulations effectively ban some aircraft from operation over populated areas, impose curfews on airports and, in conjunction with local civil aviation rules, levy extra taxes and quotas on noisier equipment. Jet engine manufacturers have attempted to increase the flow laminarity, decrease the exhaust speed and develop acoustic liners for selected duct areas. Retrofits are, however, not usually cost effective due to increased operational costs, e.g., fuel consumption can increase after engine modification because of increased weight. Finally, an attempt is made to assess, monetarily, the costs of noise pollution, wherein fines are levied for noisy aircraft and the money is spent insulating homes from noise.
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Perspectives on Highly Adaptive or Morphing Aircraft
McGowan, Anna-Maria R.; Vicroy, Dan D.; Busan, Ronald C.; Hahn, Andrew S.
2009-01-01
The ability to adapt to different flight conditions has been fundamental to aircraft design since the Wright Brothers first flight. Over a hundred years later, unconventional aircraft adaptability, often called aircraft morphing has become a topic of considerable renewed interest. In the past two decades, this interest has been largely fuelled by advancements in multi-functional or smart materials and structures. However, highly adaptive or morphing aircraft is certainly a cross-discipline challenge that stimulates a wide range of design possibilities. This paper will review some of the history of morphing aircraft including recent research programs and discuss some perspectives on this work.
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A Generic Guidance and Control Structure for Six-Degree-of-Freedom Conceptual Aircraft Design
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.
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Obrien, W. J.
1976-01-01
Concept design is presented for two types of lift/cruise fan technology V/STOL aircraft, turbotip fans and the other using mechanically driven fans. The turbotip research technology aircraft reflects maximum usage of existing airframe components. The propulsion system consists of three turbotip fans pneumatically interconnected to three gas generators. Thrust modulation is accomplished by use of energy transfer and control system and thrust reduction modulation. This system can also be operated in the two engine/three fan mode. The mechanical RTA is virtually identical to the turbotip RTA with the exceptions that a different propulsion system and aft fuselage/tail are used. Both aircraft meet or exceed all of the mission performance guidelines and reflect a low cost, low risk approach.
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Recent experience with multidisciplinary analysis and optimization in advanced aircraft design
Dollyhigh, Samuel M.; Sobieszczanski-Sobieski, Jaroslaw
1990-01-01
The task of modern aircraft design has always been complicated due to the number of intertwined technical factors from the various engineering disciplines. Furthermore, this complexity has been rapidly increasing by the development of such technologies as aeroelasticity tailored materials and structures, active control systems, integrated propulsion/airframe controls, thrust vectoring, and so on. Successful designs that achieve maximum advantage from these new technologies require a thorough understanding of the physical phenomena and the interactions among these phenomena. A study commissioned by the Aeronautical Sciences and Evaluation Board of the National Research Council has gone so far as to identify technology integration as a new discipline from which many future aeronautical advancements will arise. Regardless of whether one considers integration as a new discipline or not, it is clear to all engineers involved in aircraft design and analysis that better methods are required. In the past, designers conducted parametric studies in which a relatively small number of principal characteristics were varied to determine the effect on design requirements which were themselves often diverse and contradictory. Once a design was chosen, it then passed through the various engineers' disciplines whose principal task was to make the chosen design workable. Working in a limited design space, the discipline expert sometimes improved the concept, but more often than not, the result was in the form of a penalty to make the original concept workable. If an insurmountable problem was encountered, the process began over. Most design systems that attempt to account for disciplinary interactions have large empirical elements and reliance on past experience is a poor guide in obtaining maximum utilizations of new technologies. Further compounding the difficulty of design is that as the aeronautical sciences have matured, the discipline specialist's area of research has generally
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Airfoil optimization for morphing aircraft
Namgoong, Howoong
Continuous variation of the aircraft wing shape to improve aerodynamic performance over a wide range of flight conditions is one of the objectives of morphing aircraft design efforts. This is being pursued because of the development of new materials and actuation systems that might allow this shape change. The main purpose of this research is to establish appropriate problem formulations and optimization strategies to design an airfoil for morphing aircraft that include the energy required for shape change. A morphing aircraft can deform its wing shape, so the aircraft wing has different optimum shapes as the flight condition changes. The actuation energy needed for moving the airfoil surface is modeled and used as another design objective. Several multi-objective approaches are applied to a low-speed, incompressible flow problem and to a problem involving low-speed and transonic flow. The resulting solutions provide the best tradeoff between low drag, high energy and higher drag, low energy sets of airfoil shapes. From this range of solutions, design decisions can be made about how much energy is needed to achieve a desired aerodynamic performance. Additionally, an approach to model aerodynamic work, which would be more realistic and may allow using pressure on the airfoil to assist a morphing shape change, was formulated and used as part of the energy objective. These results suggest that it may be possible to design a morphing airfoil that exploits the airflow to reduce actuator energy.
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Design, Specification, and Synthesis of Aircraft Electric Power Systems Control Logic
Xu, Huan
Cyber-physical systems integrate computation, networking, and physical processes. Substantial research challenges exist in the design and verification of such large-scale, distributed sensing, actuation, and control systems. Rapidly improving technology and recent advances in control theory, networked systems, and computer science give us the opportunity to drastically improve our approach to integrated flow of information and cooperative behavior. Current systems rely on text-based specifications and manual design. Using new technology advances, we can create easier, more efficient, and cheaper ways of developing these control systems. This thesis will focus on design considerations for system topologies, ways to formally and automatically specify requirements, and methods to synthesize reactive control protocols, all within the context of an aircraft electric power system as a representative application area. This thesis consists of three complementary parts: synthesis, specification, and design. The first section focuses on the synthesis of central and distributed reactive controllers for an aircraft elec- tric power system. This approach incorporates methodologies from computer science and control. The resulting controllers are correct by construction with respect to system requirements, which are formulated using the specification language of linear temporal logic (LTL). The second section addresses how to formally specify requirements and introduces a domain-specific language for electric power systems. A software tool automatically converts high-level requirements into LTL and synthesizes a controller. The final sections focus on design space exploration. A design methodology is proposed that uses mixed-integer linear programming to obtain candidate topologies, which are then used to synthesize controllers. The discrete-time control logic is then verified in real-time by two methods: hardware and simulation. Finally, the problem of partial observability and
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Alternate Fuels for Use in Commercial Aircraft
Daggett, David L.; Hendricks, Robert C.; Walther, Rainer; Corporan, Edwin
2008-01-01
The engine and aircraft Research and Development (R&D) communities have been investigating alternative fueling in near-term, midterm, and far-term aircraft. A drop in jet fuel replacement, consisting of a kerosene (Jet-A) and synthetic fuel blend, will be possible for use in existing and near-term aircraft. Future midterm aircraft may use a biojet and synthetic fuel blend in ultra-efficient airplane designs. Future far-term engines and aircraft in 50-plus years may be specifically designed to use a low- or zero-carbon fuel. Synthetic jet fuels from coal, natural gas, or other hydrocarbon feedstocks are very similar in performance to conventional jet fuel, yet the additional CO2 produced during the manufacturing needs to be permanently sequestered. Biojet fuels need to be developed specifically for jet aircraft without displacing food production. Envisioned as midterm aircraft fuel, if the performance and cost liabilities can be overcome, biofuel blends with synthetic jet or Jet-A fuels have near-term potential in terms of global climatic concerns. Long-term solutions address dramatic emissions reductions through use of alternate aircraft fuels such as liquid hydrogen or liquid methane. Either of these new aircraft fuels will require an enormous change in infrastructure and thus engine and airplane design. Life-cycle environmental questions need to be addressed.
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Predicting visibility of aircraft.
Directory of Open Access Journals (Sweden)
Andrew Watson
Full Text Available Visual detection of aircraft by human observers is an important element of aviation safety. To assess and ensure safety, it would be useful to be able to be able to predict the visibility, to a human observer, of an aircraft of specified size, shape, distance, and coloration. Examples include assuring safe separation among aircraft and between aircraft and unmanned vehicles, design of airport control towers, and efforts to enhance or suppress the visibility of military and rescue vehicles. We have recently developed a simple metric of pattern visibility, the Spatial Standard Observer (SSO. In this report we examine whether the SSO can predict visibility of simulated aircraft images. We constructed a set of aircraft images from three-dimensional computer graphic models, and measured the luminance contrast threshold for each image from three human observers. The data were well predicted by the SSO. Finally, we show how to use the SSO to predict visibility range for aircraft of arbitrary size, shape, distance, and coloration.
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Li, M.O.
2014-01-01
Air-to-air refuelling is a way to improve fuel efficiency of the overall transport system without waiting for the improvement of basic aviation technology. To take full advantage of such an operation, both passenger aircraft and tanker aircraft (which deliver required fuel to the passenger aircraft
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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.
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Soft shell hard core concept for aircraft impact resistant design
International Nuclear Information System (INIS)
Chen, C.; Rieck, P.J.
1978-01-01
For nuclear power plants sited in the vicinity of airports, the hypothetical events of aircraft impact have to be designed for. The conventional design concept is to strengthen the exterior structure to resist the impact induced force. The stiffened structures have two (2) disadvantages; one is the high construction cost, and the other is the high reaction force induced as well as the vibrational effects on the interior equipment and piping systems. This new soft shell hard core concept can relieve the above shortcomings. In this concept, the essential equipment required for safety are installed inside the hard core area for protection and the non-essential equipment are maintained between the hard core and soft shell area. During a hypothetical impact event, the soft shell will collapse locally and absorb large amounts of kinetic energy; hence, it reduces the reaction force and the vibrational effects. The design and analysis of the soft shell concept are discussed. (Author)
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Yondo, Raul; Andrés, Esther; Valero, Eusebio
2018-01-01
Full scale aerodynamic wind tunnel testing, numerical simulation of high dimensional (full-order) aerodynamic models or flight testing are some of the fundamental but complex steps in the various design phases of recent civil transport aircrafts. Current aircraft aerodynamic designs have increase in complexity (multidisciplinary, multi-objective or multi-fidelity) and need to address the challenges posed by the nonlinearity of the objective functions and constraints, uncertainty quantification in aerodynamic problems or the restrained computational budgets. With the aim to reduce the computational burden and generate low-cost but accurate models that mimic those full order models at different values of the design variables, Recent progresses have witnessed the introduction, in real-time and many-query analyses, of surrogate-based approaches as rapid and cheaper to simulate models. In this paper, a comprehensive and state-of-the art survey on common surrogate modeling techniques and surrogate-based optimization methods is given, with an emphasis on models selection and validation, dimensionality reduction, sensitivity analyses, constraints handling or infill and stopping criteria. Benefits, drawbacks and comparative discussions in applying those methods are described. Furthermore, the paper familiarizes the readers with surrogate models that have been successfully applied to the general field of fluid dynamics, but not yet in the aerospace industry. Additionally, the review revisits the most popular sampling strategies used in conducting physical and simulation-based experiments in aircraft aerodynamic design. Attractive or smart designs infrequently used in the field and discussions on advanced sampling methodologies are presented, to give a glance on the various efficient possibilities to a priori sample the parameter space. Closing remarks foster on future perspectives, challenges and shortcomings associated with the use of surrogate models by aircraft industrial
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Beryllium in aircraft brakes - a summary
International Nuclear Information System (INIS)
Zenczak, S.
1977-01-01
Beryllium has been in use in aircraft brakes for ten years. During the original design phases of the several aircraft programs using beryllium a number of problems requiring solution confronted the designers. In actual service the solution to these problems performed much better than had been anticipated. A summary is presented. (author)
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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.
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Multidisciplinary Techniques and Novel Aircraft Control Systems
Padula, Sharon L.; Rogers, James L.; Raney, David L.
2000-01-01
The Aircraft Morphing Program at NASA Langley Research Center explores opportunities to improve airframe designs with smart technologies. Two elements of this basic research program are multidisciplinary design optimization (MDO) and advanced flow control. This paper describes examples where MDO techniques such as sensitivity analysis, automatic differentiation, and genetic algorithms contribute to the design of novel control systems. In the test case, the design and use of distributed shape-change devices to provide low-rate maneuvering capability for a tailless aircraft is considered. The ability of MDO to add value to control system development is illustrated using results from several years of research funded by the Aircraft Morphing Program.
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Development and experimental characterization of a fuel cell powered aircraft
Energy Technology Data Exchange (ETDEWEB)
Bradley, Thomas H.; Moffitt, Blake A.; Mavris, Dimitri N.; Parekh, David E. [Georgia Institute of Technology, Atlanta, GA 30332-0405 (United States)
2007-09-27
This paper describes the characteristics and performance of a fuel cell powered unmanned aircraft. The aircraft is novel as it is the largest compressed hydrogen fuel cell powered airplane built to date and is currently the only fuel cell aircraft whose design and test results are in the public domain. The aircraft features a 500 W polymer electrolyte membrane fuel cell with full balance of plant and compressed hydrogen storage incorporated into a custom airframe. Details regarding the design requirements, implementation and control of the aircraft are presented for each major aircraft system. The performances of the aircraft and powerplant are analyzed using data from flights and laboratory tests. The efficiency and component power consumption of the fuel cell propulsion system are measured at a variety of flight conditions. The performance of the aircraft powerplant is compared to other 0.5-1 kW-scale fuel cell powerplants in the literature and means of performance improvement for this aircraft are proposed. This work represents one of the first studies of fuel cell powered aircraft to result in a demonstration aircraft. As such, the results of this study are of practical interest to fuel cell powerplant and aircraft designers. (author)
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Future aircraft networks and schedules
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
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Design & fabrication of two seated aircraft with an advanced rotating leading edge wing
Al Ahmari, Saeed Abdullah Saeed
The title of this thesis is "Design & Fabrication of two Seated Aircraft with an Advanced Rotating Leading Edge Wing", this gives almost a good description of the work has been done. In this research, the moving surface boundary-layer control (MSBC) concept was investigated and implemented. An experimental model was constructed and tested in wind tunnel to determine the aerodynamic characteristics using the leading edge moving surface of modified semi-symmetric airfoil NACA1214. The moving surface is provided by a high speed rotating cylinder, which replaces the leading edge of the airfoil. The angle of attack, the cylinder surfaces velocity ratio Uc/U, and the flap deflection angle effects on the lift and drag coefficients and the stall angle of attack were investigated. This new technology was applied to a 2-seat light-sport aircraft that is designed and built in the Aerospace Engineering Department at KFUPM. The project team is led by the aerospace department chairman Dr. Ahmed Z. AL-Garni and Dr. Wael G. Abdelrahman and includes graduate and under graduate student. The wing was modified to include a rotating cylinder along the leading edge of the flap portion. This produced very promising results such as the increase of the maximum lift coefficient at Uc/U=3 by 82% when flaps up and 111% when flaps down at 40° and stall was delayed by 8degrees in both cases. The laboratory results also showed that the effective range of the leading-edge rotating cylinder is at low angles of attack which reduce the need for higher angles of attack for STOL aircraft.
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Design Challenges Encountered in a Propulsion-Controlled Aircraft Flight Test Program
Maine, Trindel; Burken, John; Burcham, Frank; Schaefer, Peter
1994-01-01
The NASA Dryden Flight Research Center conducted flight tests of a propulsion-controlled aircraft system on an F-15 airplane. This system was designed to explore the feasibility of providing safe emergency landing capability using only the engines to provide flight control in the event of a catastrophic loss of conventional flight controls. Control laws were designed to control the flightpath and bank angle using only commands to the throttles. Although the program was highly successful, this paper highlights some of the challenges associated with using engine thrust as a control effector. These challenges include slow engine response time, poorly modeled nonlinear engine dynamics, unmodeled inlet-airframe interactions, and difficulties with ground effect and gust rejection. Flight and simulation data illustrate these difficulties.
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Aircraft bi-level life cycle cost estimation
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,
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Design of a fuel-efficient guidance system for a STOL aircraft
Mclean, J. D.; Erzberger, H.
1981-01-01
In the predictive mode, the system synthesizes a horizontal path from an initial aircraft position and heading to a desired final position and heading and then synthesizes a fuel-efficient speed-altitude profile along the path. In the track mode, the synthesized trajectory is reconstructed and tracked automatically. An analytical basis for the design of the system is presented and a description of the airborne computer implementation is given. A detailed discussion of the software, which should be helpful to those who use the actual software developed for these tests, is also provided.
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Role of Wind Tunnels in Aircraft Design
Indian Academy of Sciences (India)
S P Govinda Raju. Aircraft of various types are necessary for meeting the ... configuration is thoroughly evaluated for performance, stabil- ity and controllability .... Specialised tests, like those for measuring various stability de- rivatives involve ...
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Tudor, Magdalena
IATA has estimated, in 2012, at about 2% of global carbon dioxide emissions, the environmental impact of the air transport, as a consequence caused by the rapidly growing of global movement demand of people and goods, and which was effectively taken into account in the development of the aviation industry. The historic achievements of scientific and technical progress in the field of commercial aviation were contributed to this estimate, and even today the research continues to make progress to help to reduce the emissions of greenhouse gases. Advances in commercial aircraft, and its engine design technology had the aim to improve flight performance. These improvements have enhanced the global flight planning of these types of aircrafts. Almost all of these advances rely on generated performance data as reference sources, the most of which are classified as "confidential" by the aircraft manufacturers. There are very few aero-propulsive models conceived for the climb regime in the literature, but none of them was designed without access to an engine database, and/or to performance data in climb and in cruise regimes with direct applicability for flight optimization. In this thesis, aero-propulsive models methodologies are proposed for climb and cruise regimes, using system identification and validation methods, through which airplane performance can be computed and stored in the most compact and easily accessible format for this kind of performance data. The acquiring of performance data in this format makes it possible to optimize flight profiles, used by on-board Flight Management Systems. The aero-propulsive models developed here were investigated on two aircrafts belonging to commercial class, and both of them had offered very good accuracy. One of their advantages is that they can be adapted to any other aircraft of the same class, even if there is no access to their corresponding engine flight data. In addition, these models could save airlines a considerable
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Bodlak, Eric
Within the last decade, multi-rotor aircraft have become the most prevalent form of unmanned aerial vehicle (UAV), with applications in the military, commercial, and civilian sectors. This is due primarily to advances in electronics that allow small-scale aircraft systems to be produced and controlled in an affordable manner. Such systems are maneuvered by precisely varying the thrust and torque of individual rotors to produce flight control forces, thereby eliminating much of the mechanical complexity inherent in conventional helicopter configurations. Although many UAV missions exploit the ability to hover in place, many also require the ability to quickly and efficiently dash from point to point. Rotorcraft, in general, are limited in this capacity, since rotor thrust must also be used to produce lift. Transitional aircraft represent an alternative that blends the vertical take-off and landing (VTOL) capabilities of rotorcraft with the forward flight performance of fixed-wing aircraft, but they often rely on cumbersome mechanisms, such as additional or rotating powerplants. UAVs, however, have no need to maintain cockpit orientation. Consequently, a tailsitting quadcopter concept was devised by Dr. Ron Barrett to combine quadcopter hovering performance with the high-speed flight of fixed-wing craft. This paper lays out the arguments for such an aircraft--the XQ-139 --and examines the performance of XQ-139 variants with installed power values ranging from 100 W to 10,000 kW. Battery-electric, rotary engine, turboprop, and hybrid propulsive options are considered, and the merits of each discussed. Additionally, an XQ-139 prototype was designed and constructed, and stationary test was used to compare the aircraft's installed efficiency with that of a typical quadcopter. The prototype was found to be approximately 5% more efficient in hover mode than the quadcopter to which it was compared.
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Design and development of a unit element microstrip antenna for aircraft collision avoidance system
De, Debajit; Sahu, Prasanna Kumar
2017-10-01
Aircraft/traffic alert and collision avoidance system (ACAS/TCAS) is an airborne system which is designed to provide the service as a last defense equipment for avoiding mid-air collisions between the aircraft. In the existing system, four monopole stub-elements are used as ACAS directional antenna and one blade type element is used as ACAS omnidirectional antenna. The existing ACAS antenna has some drawbacks such as low gain, large beamwidth, frequency and beam tuning/scanning issues etc. Antenna issues like unwanted signals reception may create difficulties to identify the possible threats. In this paper, the focus is on the design and development of a unit element microstrip antenna which can be used for ACAS application and to overcome the possible limitations associated with the existing techniques. Two proposed antenna models are presented here, which are single feed and dual feed microstrip dual patch slotted antenna. These are designed and simulated in CST Microwave Studio tool. The performance and other antenna characteristics have been explored from the simulation results followed by the antenna fabrication and measurement. A good reflection coefficient, Voltage Standing Wave Ratio (VSWR), narrow beamwidth, perfect directional radiation pattern, high gain and directivity make this proposed antenna a good candidate for this application.
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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....
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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.
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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.
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Geiselhart, Karl A.; Ozoroski, Lori P.; Fenbert, James W.; Shields, Elwood W.; Li, Wu
2011-01-01
This paper documents the development of a conceptual level integrated process for design and analysis of efficient and environmentally acceptable supersonic aircraft. To overcome the technical challenges to achieve this goal, a conceptual design capability which provides users with the ability to examine the integrated solution between all disciplines and facilitates the application of multidiscipline design, analysis, and optimization on a scale greater than previously achieved, is needed. The described capability is both an interactive design environment as well as a high powered optimization system with a unique blend of low, mixed and high-fidelity engineering tools combined together in the software integration framework, ModelCenter. The various modules are described and capabilities of the system are demonstrated. The current limitations and proposed future enhancements are also discussed.
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Alexander, H. R.; Smith, K. E.; Mcveigh, M. A.; Dixon, P. G.; Mcmanus, B. L.
1979-01-01
Composite structures technology is applied in a preliminary design study of advanced technology blades and hubs for the XV-15 tilt rotor research demonstrator aircraft. Significant improvements in XV-15 hover and cruise performance are available using blades designed for compatibility with the existing aircraft, i.e., blade installation would not require modification of the airframe, hub or upper controls. Provision of a low risk nonmechanical control system was also studied, and a development specification is given.
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Chwalowski, Pawel; Samareh, Jamshid A.; Horta, Lucas G.; Piatak, David J.; McGowan, Anna-Maria R.
2009-01-01
The conceptual and preliminary design processes for aircraft with large shape changes are generally difficult and time-consuming, and the processes are often customized for a specific shape change concept to streamline the vehicle design effort. Accordingly, several existing reports show excellent results of assessing a particular shape change concept or perturbations of a concept. The goal of the current effort was to develop a multidisciplinary analysis tool and process that would enable an aircraft designer to assess several very different morphing concepts early in the design phase and yet obtain second-order performance results so that design decisions can be made with better confidence. The approach uses an efficient parametric model formulation that allows automatic model generation for systems undergoing radical shape changes as a function of aerodynamic parameters, geometry parameters, and shape change parameters. In contrast to other more self-contained approaches, the approach utilizes off-the-shelf analysis modules to reduce development time and to make it accessible to many users. Because the analysis is loosely coupled, discipline modules like a multibody code can be easily swapped for other modules with similar capabilities. One of the advantages of this loosely coupled system is the ability to use the medium- to high-fidelity tools early in the design stages when the information can significantly influence and improve overall vehicle design. Data transfer among the analysis modules are based on an accurate and automated general purpose data transfer tool. In general, setup time for the integrated system presented in this paper is 2-4 days for simple shape change concepts and 1-2 weeks for more mechanically complicated concepts. Some of the key elements briefly described in the paper include parametric model development, aerodynamic database generation, multibody analysis, and the required software modules as well as examples for a telescoping wing
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Analytical Design Package (ADP2): A computer aided engineering tool for aircraft transparency design
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.
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Aircraft Electric Propulsion Systems Applied Research at NASA
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.
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PRINCIPLE "EARLY MATCHING" AERODYNAMIC DESIGN AIRCRAFT WITH LANDING GEAR HOVERCRAFT
Directory of Open Access Journals (Sweden)
V. P. Morozov
2015-01-01
Full Text Available The principle of "early matching" aircraft aerohydrodynamic layouts with air cushion landing gear is suggested. Application of this principle is considered as an example of adaptation to the ball screw base circuit of light transport aircraft. The principle, other than weight, aerodynamic, technological and operational requirements includes additional project activities related to the installation of ball screws.
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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
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Small Transport Aircraft Technology /STAT/ Propulsion Study
Heldenbrand, R. W.; Baerst, C. F.; Rowse, J. H.
1980-01-01
The NASA Small Transport Aircraft Technology (STAT) Propulsion Study was established to identify technology requirements and define the research and development required for new commuter aircraft. Interim results of the studies defined mission and design characteristics for 30- and 50-passenger aircraft. Sensitivities were defined that relate changes in engine specific fuel consumption (SFC), weight, and cost (including maintenance) to changes in the aircraft direct operating cost (DOC), takeoff gross weight, and empty weight. A comparison of performance and economic characteristics is presented between aircraft powered by 1980 production engines and those powered by a 1990 advanced technology baseline engine.
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NASA Electric Aircraft Test Bed (NEAT) Development Plan - Design, Fabrication, Installation
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.
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Directory of Open Access Journals (Sweden)
Ishaan PRAKASH
2017-09-01
Full Text Available Recent trends in aircraft design research have resulted in development of many unconventional configurations mostly aimed at improving aerodynamic efficiency. The blended wing body (BWB is one such configuration that holds potential in this regard. In its current form the BWB although promises a better lift to drag (L/D ratio it is still not able to function to its maximum capability due to design modifications such as twist and reflexed airfoils to overcome stability problems in the absence of a tail. This work aims to maximize the impact of a BWB. A design approach of morphing the BWB with a conventional aft fuselage is proposed. Such a configuration intends to impart full freedom to the main wing and the blended forward fuselage to contribute in lift production while the conventional tail makes up for stability. The aft fuselage, meanwhile, also ensures that the aircraft is compatible with current loading and airdrop operations. This paper is the culmination of obtained models results and inferences from the first phase of the project wherein development of aerodynamic design and analysis methodologies and mission specific optimization have been undertaken.
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Reduction environmental effects of civil aircraft through multi-objective flight plan optimisation
International Nuclear Information System (INIS)
Lee, D S; Gonzalez, L F; Walker, R; Periaux, J; Onate, E
2010-01-01
With rising environmental alarm, the reduction of critical aircraft emissions including carbon dioxides (CO 2 ) and nitrogen oxides (NO x ) is one of most important aeronautical problems. There can be many possible attempts to solve such problem by designing new wing/aircraft shape, new efficient engine, etc. The paper rather provides a set of acceptable flight plans as a first step besides replacing current aircrafts. The paper investigates a green aircraft design optimisation in terms of aircraft range, mission fuel weight (CO 2 ) and NO x using advanced Evolutionary Algorithms coupled to flight optimisation system software. Two multi-objective design optimisations are conducted to find the best set of flight plans for current aircrafts considering discretised altitude and Mach numbers without designing aircraft shape and engine types. The objectives of first optimisation are to maximise range of aircraft while minimising NO x with constant mission fuel weight. The second optimisation considers minimisation of mission fuel weight and NO x with fixed aircraft range. Numerical results show that the method is able to capture a set of useful trade-offs that reduce NO x and CO 2 (minimum mission fuel weight).
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International Nuclear Information System (INIS)
Rancruel, Diego F.; Spakovsky, Michael R. von
2006-01-01
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
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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.
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Information note about the protection of nuclear facilities against aircraft crashes
International Nuclear Information System (INIS)
2001-01-01
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). 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.)
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Multifuel rotary aircraft engine
Jones, C.; Berkowitz, M.
1980-01-01
The broad objectives of this paper are the following: (1) to summarize the Curtiss-Wright design, development and field testing background in the area of rotary aircraft engines; (2) to briefly summarize past activity and update development work in the area of stratified charge rotary combustion engines; and (3) to discuss the development of a high-performance direct injected unthrottled stratified charge rotary combustion aircraft engine. Efficiency improvements through turbocharging are also discussed.
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Parallel Aircraft Trajectory Optimization with Analytic Derivatives
Falck, Robert D.; Gray, Justin S.; Naylor, Bret
2016-01-01
Trajectory optimization is an integral component for the design of aerospace vehicles, but emerging aircraft technologies have introduced new demands on trajectory analysis that current tools are not well suited to address. Designing aircraft with technologies such as hybrid electric propulsion and morphing wings requires consideration of the operational behavior as well as the physical design characteristics of the aircraft. The addition of operational variables can dramatically increase the number of design variables which motivates the use of gradient based optimization with analytic derivatives to solve the larger optimization problems. In this work we develop an aircraft trajectory analysis tool using a Legendre-Gauss-Lobatto based collocation scheme, providing analytic derivatives via the OpenMDAO multidisciplinary optimization framework. This collocation method uses an implicit time integration scheme that provides a high degree of sparsity and thus several potential options for parallelization. The performance of the new implementation was investigated via a series of single and multi-trajectory optimizations using a combination of parallel computing and constraint aggregation. The computational performance results show that in order to take full advantage of the sparsity in the problem it is vital to parallelize both the non-linear analysis evaluations and the derivative computations themselves. The constraint aggregation results showed a significant numerical challenge due to difficulty in achieving tight convergence tolerances. Overall, the results demonstrate the value of applying analytic derivatives to trajectory optimization problems and lay the foundation for future application of this collocation based method to the design of aircraft with where operational scheduling of technologies is key to achieving good performance.
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Fault Tolerance, Diagnostics, and Prognostics in Aircraft Flight
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...
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Subsonic Ultra Green Aircraft Research. Phase II - Volume I; Truss Braced Wing Design Exploration
Bradley, Marty K.; Droney, Christopher K.; Allen, Timothy J.
2015-01-01
This report summarizes the Truss Braced Wing (TBW) work accomplished by the Boeing Subsonic Ultra Green Aircraft Research (SUGAR) team, consisting of Boeing Research and Technology, Boeing Commercial Airplanes, General Electric, Georgia Tech, Virginia Tech, NextGen Aeronautics, and Microcraft. A multi-disciplinary optimization (MDO) environment defined the geometry that was further refined for the updated SUGAR High TBW configuration. Airfoil shapes were tested in the NASA TCT facility, and an aeroelastic model was tested in the NASA TDT facility. Flutter suppression was successfully demonstrated using control laws derived from test system ID data and analysis models. Aeroelastic impacts for the TBW design are manageable and smaller than assumed in Phase I. Flutter analysis of TBW designs need to include pre-load and large displacement non-linear effects to obtain a reasonable match to test data. With the updated performance and sizing, fuel burn and energy use is reduced by 54% compared to the SUGAR Free current technology Baseline (Goal 60%). Use of the unducted fan version of the engine reduces fuel burn and energy by 56% compared to the Baseline. Technology development roadmaps were updated, and an airport compatibility analysis established feasibility of a folding wing aircraft at existing airports.
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Sakata, I. F.; Davis, G. W.
1975-01-01
The design of an economically viable supersonic cruise aircraft requires the lowest attainable structural-mass fraction commensurate with the selected near-term structural material technology. To achieve this goal of minimum structural-mass fraction, various combinations of promising wing and fuselage primary structure were analyzed for the load-temperature environment applicable to the arrow wing configuration. This analysis was conducted in accordance with the design criteria specified and included extensive use of computer-aided analytical methods to screen the candidate concepts and select the most promising concepts for the in-depth structural analysis.
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Modelling and Designing Cryogenic Hydrogen Tanks for Future Aircraft Applications
Directory of Open Access Journals (Sweden)
Christopher Winnefeld
2018-01-01
Full Text Available In the near future, the challenges to reduce the economic and social dependency on fossil fuels must be faced increasingly. A sustainable and efficient energy supply based on renewable energies enables large-scale applications of electro-fuels for, e.g., the transport sector. The high gravimetric energy density makes liquefied hydrogen a reasonable candidate for energy storage in a light-weight application, such as aviation. Current aircraft structures are designed to accommodate jet fuel and gas turbines allowing a limited retrofitting only. New designs, such as the blended-wing-body, enable a more flexible integration of new storage technologies and energy converters, e.g., cryogenic hydrogen tanks and fuel cells. Against this background, a tank-design model is formulated, which considers geometrical, mechanical and thermal aspects, as well as specific mission profiles while considering a power supply by a fuel cell. This design approach enables the determination of required tank mass and storage density, respectively. A new evaluation value is defined including the vented hydrogen mass throughout the flight enabling more transparent insights on mass shares. Subsequently, a systematic approach in tank partitioning leads to associated compromises regarding the tank weight. The analysis shows that cryogenic hydrogen tanks are highly competitive with kerosene tanks in terms of overall mass, which is further improved by the use of a fuel cell.
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Daedalus Project's Light Eagle - Human powered aircraft
1987-01-01
The Michelob Light Eagle is seen here in flight over Rogers Dry Lake at the NASA Dryden Flight Research Center, Edwards, California. The Light Eagle and Daedalus human powered aircraft were testbeds for flight research conducted at Dryden between January 1987 and March 1988. These unique aircraft were designed and constructed by a group of students, professors, and alumni of the Massachusetts Institute of Technology within the context of the Daedalus project. The construction of the Light Eagle and Daedalus aircraft was funded primarily by the Anheuser Busch and United Technologies Corporations, respectively, with additional support from the Smithsonian Air and Space Museum, MIT, and a number of other sponsors. To celebrate the Greek myth of Daedalus, the man who constructed wings of wax and feathers to escape King Minos, the Daedalus project began with the goal of designing, building and testing a human-powered aircraft that could fly the mythical distance, 115 km. To achieve this goal, three aircraft were constructed. The Light Eagle was the prototype aircraft, weighing 92 pounds. On January 22, 1987, it set a closed course distance record of 59 km, which still stands. Also in January of 1987, the Light Eagle was powered by Lois McCallin to set the straight distance, the distance around a closed circuit, and the duration world records for the female division in human powered vehicles. Following this success, two more aircraft were built, the Daedalus 87 and Daedalus 88. Each aircraft weighed approximately 69 pounds. The Daedalus 88 aircraft was the ship that flew the 199 km from the Iraklion Air Force Base on Crete in the Mediterranean Sea, to the island of Santorini in 3 hours, 54 minutes. In the process, the aircraft set new records in distance and endurance for a human powered aircraft. The specific areas of flight research conducted at Dryden included characterizing the rigid body and flexible dynamics of the Light Eagle, investigating sensors for an
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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.
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Application of automation for low cost aircraft cabin simulator
Tan, C.F.; Chen, W.; Boomen, van den G.J.A.; Rauterberg, G.W.M.
2010-01-01
This paper presents an application of automation for low cost aircraft cabin simulator. The aircraft cabin simulator is a testbed that was designed for research on aircraft passenger comfort mprovement product. The simulator consists of an economy class section, a business class section, a lavatory
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Welstead, Jason
2014-01-01
This research focused on incorporating stability and control into a multidisciplinary de- sign optimization on a Boeing 737-class advanced concept called the D8.2b. A new method of evaluating the aircraft handling performance using quantitative evaluation of the sys- tem to disturbances, including perturbations, continuous turbulence, and discrete gusts, is presented. A multidisciplinary design optimization was performed using the D8.2b transport air- craft concept. The con guration was optimized for minimum fuel burn using a design range of 3,000 nautical miles. Optimization cases were run using xed tail volume coecients, static trim constraints, and static trim and dynamic response constraints. A Cessna 182T model was used to test the various dynamic analysis components, ensuring the analysis was behaving as expected. Results of the optimizations show that including stability and con- trol in the design process drastically alters the optimal design, indicating that stability and control should be included in conceptual design to avoid system level penalties later in the design process.
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Night vision imaging systems design, integration, and verification in military fighter aircraft
Sabatini, Roberto; Richardson, Mark A.; Cantiello, Maurizio; Toscano, Mario; Fiorini, Pietro; Jia, Huamin; Zammit-Mangion, David
2012-04-01
This paper describes the developmental and testing activities conducted by the Italian Air Force Official Test Centre (RSV) in collaboration with Alenia Aerospace, Litton Precision Products and Cranfiled University, in order to confer the Night Vision Imaging Systems (NVIS) capability to the Italian TORNADO IDS (Interdiction and Strike) and ECR (Electronic Combat and Reconnaissance) aircraft. The activities consisted of various Design, Development, Test and Evaluation (DDT&E) activities, including Night Vision Goggles (NVG) integration, cockpit instruments and external lighting modifications, as well as various ground test sessions and a total of eighteen flight test sorties. RSV and Litton Precision Products were responsible of coordinating and conducting the installation activities of the internal and external lights. Particularly, an iterative process was established, allowing an in-site rapid correction of the major deficiencies encountered during the ground and flight test sessions. Both single-ship (day/night) and formation (night) flights were performed, shared between the Test Crews involved in the activities, allowing for a redundant examination of the various test items by all participants. An innovative test matrix was developed and implemented by RSV for assessing the operational suitability and effectiveness of the various modifications implemented. Also important was definition of test criteria for Pilot and Weapon Systems Officer (WSO) workload assessment during the accomplishment of various operational tasks during NVG missions. Furthermore, the specific technical and operational elements required for evaluating the modified helmets were identified, allowing an exhaustive comparative evaluation of the two proposed solutions (i.e., HGU-55P and HGU-55G modified helmets). The results of the activities were very satisfactory. The initial compatibility problems encountered were progressively mitigated by incorporating modifications both in the front and
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Aircraft Evaluation Using Stochastic Duels
2017-09-01
for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302, and to the Office of Management and...Fighter aircraft systems and weapons designs are known to involve substantial capital investment . Due to possible budget constraints in the U.S. Navy, the...of fighter aircraft to analysts and decision-makers before they invest further resources into larger-scale, higher-resolution simulations for
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Study of fuel systems for LH2-fueled subsonic transport aircraft, volume 1
Brewer, G. D.; Morris, R. E.; Davis, G. W.; Versaw, E. F.; Cunnington, G. R., Jr.; Riple, J. C.; Baerst, C. F.; Garmong, G.
1978-01-01
Several engine concepts examined to determine a preferred design which most effectively exploits the characteristics of hydrogen fuel in aircraft tanks received major emphasis. Many candidate designs of tank structure and cryogenic insulation systems were evaluated. Designs of all major elements of the aircraft fuel system including pumps, lines, valves, regulators, and heat exchangers received attention. Selected designs of boost pumps to be mounted in the LH2 tanks, and of a high pressure pump to be mounted on the engine were defined. A final design of LH2-fueled transport aircraft was established which incorporates a preferred design of fuel system. That aircraft was then compared with a conventionally fueled counterpart designed to equivalent technology standards.
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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.
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Fuel-Conservation Guidance System for Powered-Lift Aircraft
Erzberger, Heinz; McLean, John D.
1981-01-01
A technique is described for the design of fuel-conservative guidance systems and is applied to a system that was flight tested on board NASA's sugmentor wing jet STOL research aircraft. An important operational feature of the system is its ability to rapidly synthesize fuel-efficient trajectories for a large set of initial aircraft positions, altitudes, and headings. This feature allows the aircraft to be flown efficiently under conditions of changing winds and air traffic control vectors. Rapid synthesis of fuel-efficient trajectories is accomplished in the airborne computer by fast-time trajectory integration using a simplified dynamic performance model of the aircraft. This technique also ensures optimum flap deployment and, for powered-lift STOL aircraft, optimum transition to low-speed flight. Also included in the design is accurate prediction of touchdown time for use in four-dimensional guidance applications. Flight test results have demonstrated that the automatically synthesized trajectories produce significant fuel savings relative to manually flown conventional approaches.
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Study of quiet turbofan STOL aircraft for short haul transportation
Higgins, T. P.; Stout, E. G.; Sweet, H. S.
1973-01-01
Conceptual designs of Quiet Turbofan STOL Short-Haul Transport Aircraft for the mid-1980 time period are developed and analyzed to determine their technical, operational, and economic feasibility. A matrix of aircraft using various high-lift systems and design parameters are considered. Variations in aircraft characteristics, airport geometry and location, and operational techniques are analyzed systematically to determine their effects on the market, operating economics, and community acceptance. In these studies, the total systems approach is considered to be critically important in analyzing the potential of STOL aircraft to reduce noise pollution and alleviate the increasing air corridor and airport congestion.
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Gohardani, Amir S.; Doulgeris, Georgios; Singh, Riti
2011-07-01
This paper highlights the role of distributed propulsion technology for future commercial aircraft. After an initial historical perspective on the conceptual aspects of distributed propulsion technology and a glimpse at numerous aircraft that have taken distributed propulsion technology to flight, the focal point of the review is shifted towards a potential role this technology may entail for future commercial aircraft. Technological limitations and challenges of this specific technology are also considered in combination with an all electric aircraft concept, as means of predicting the challenges associated with the design process of a next generation commercial aircraft.
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Stability Result For Dynamic Inversion Devised to Control Large Flexible Aircraft
Gregory, Irene M.
2001-01-01
High performance aircraft of the future will be designed lighter, more maneuverable, and operate over an ever expanding flight envelope. One of the largest differences from the flight control perspective between current and future advanced aircraft is elasticity. Over the last decade, dynamic inversion methodology has gained considerable popularity in application to highly maneuverable fighter aircraft, which were treated as rigid vehicles. This paper is an initial attempt to establish global stability results for dynamic inversion methodology as applied to a large, flexible aircraft. This work builds on a previous result for rigid fighter aircraft and adds a new level of complexity that is the flexible aircraft dynamics, which cannot be ignored even in the most basic flight control. The results arise from observations of the control laws designed for a new generation of the High-Speed Civil Transport aircraft.
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Bertola, Luca; Cox, Tom; Wheeler, Patrick; Garvey, Seamus D.; Morvan, Herve
2017-01-01
The engine size of modern passenger transport aircraft is principally determined by take-off conditions, since initial acceleration requires maximum engine power. An elec¬tromagnetic launch (EML) system could provide some or all of the energy required at takeoff so that the aircraft engine power requirement and fuel consumption may be significantly reduced. So far, EML for aircraft has been adopted only for military applications to replace steam catapults on the deck of aircraft carriers. Thi...
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Sakata, I. F.; Davis, G. W.
1975-01-01
The analyses performed to provide structural mass estimates for the arrow wing supersonic cruise aircraft are presented. To realize the full potential for structural mass reduction, a spectrum of approaches for the wing and fuselage primary structure design were investigated. The objective was: (1) to assess the relative merits of various structural arrangements, concepts, and materials; (2) to select the structural approach best suited for the Mach 2.7 environment; and (3) to provide construction details and structural mass estimates based on in-depth structural design studies. Production costs, propulsion-airframe integration, and advanced technology assessment are included.
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2011-02-01
http://www.redhammer.se/tornado/index.html (3) Aircraft Design: A Conceptual Approach, Daniel P. Raymer , AIAA, 1992 (4) (5) Moran, J., Computational...Fluid Dynamics, Wiley & Sons, 1984. Notes on the Stability and Control of Tailless Airplanes, Robert T. Jones, NACA Technical Note No.837, December
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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.
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AP1000R design robustness against extreme external events - Seismic, flooding, and aircraft crash
International Nuclear Information System (INIS)
Pfister, A.; Goossen, C.; Coogler, K.; Gorgemans, J.
2012-01-01
Both the International Atomic Energy Agency (IAEA) and the U.S. Nuclear Regulatory Commission (NRC) require existing and new nuclear power plants to conduct plant assessments to demonstrate the unit's ability to withstand external hazards. The events that occurred at the Fukushima-Dai-ichi nuclear power station demonstrated the importance of designing a nuclear power plant with the ability to protect the plant against extreme external hazards. The innovative design of the AP1000 R nuclear power plant provides unparalleled protection against catastrophic external events which can lead to extensive infrastructure damage and place the plant in an extended abnormal situation. The AP1000 plant is an 1100-MWe pressurized water reactor with passive safety features and extensive plant simplifications that enhance construction, operation, maintenance and safety. The plant's compact safety related footprint and protection provided by its robust nuclear island structures prevent significant damage to systems, structures, and components required to safely shutdown the plant and maintain core and spent fuel pool cooling and containment integrity following extreme external events. The AP1000 nuclear power plant has been extensively analyzed and reviewed to demonstrate that it's nuclear island design and plant layout provide protection against both design basis and extreme beyond design basis external hazards such as extreme seismic events, external flooding that exceeds the maximum probable flood limit, and malicious aircraft impact. The AP1000 nuclear power plant uses fail safe passive features to mitigate design basis accidents. The passive safety systems are designed to function without safety-grade support systems (such as AC power, component cooling water, service water, compressed air or HVAC). The plant has been designed to protect systems, structures, and components critical to placing the reactor in a safe shutdown condition within the steel containment vessel which is
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Cryogenic system options for a superconducting aircraft propulsion system
International Nuclear Information System (INIS)
Berg, F; Dodds, Graham; Palmer, J; Bertola, L; Miller, Paul
2015-01-01
There is a perceived need in the future for a move away from traditional aircraft designs in order to meet ambitious emissions and fuel burn targets. High temperature superconducting distributed propulsion may be an enabler for aircraft designs that have better propulsive efficiency and lower drag. There has been significant work considering the electrical systems required, but less on the cryogenics to enable it. This paper discusses some of the major choices to be faced in cryocooling for aircraft. The likely need for a disposable cryogen to reduce power demand is explained. A set of cryocooling methods are considered in a sensitivity study, which shows that the feasibility of the cryogenic system will depend strongly on the superconducting technology and the aircraft platform. It is argued that all three aspects must be researched and designed in close collaboration to reach a viable solution. (paper)
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Loeb, M.; Moran, S. V.
1977-01-01
It has been suggested that expressions of annoyance attributable to aircraft noise may reflect in part fear of aircraft overflights and possible crashes. If this is true, then residents of areas where crashes have occurred should express more annoyance. To test this hypothesis, 50 residents of an Albany, New York area where an aircraft crash producing fatalities recently occurred and 50 residents of a comparable nearby area without such a history, were asked to respond to a 'Quality of Life Questionnaire.' Among the items were some designed to test annoyance by noise and fear of aircraft overflights. It was predicted that those in the crash area would express more fear and would more often identify aircraft as a noise source. These hypotheses were sustained. A near-replication was carried out in Louisville, Kentucky; results were much the same. Analyses indicated that for the crash-area groups, there was associating of aircraft fear and noise annoyance responses; this was true to an apparently lesser extent for non-crash groups. The greater annoyance of crash groups by aircraft community noise apparently does not carry over to situations in which aircraft noise is assessed in the laboratory.
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Control of Next Generation Aircraft and Wind Turbines
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.
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Pilot Designed Aircraft Displays in General Aviation: An Exploratory Study and Analysis
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
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Advanced technology for future regional transport aircraft
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.
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Automated Inspection of Aircraft
1998-04-01
This report summarizes the development of a robotic system designed to assist aircraft inspectors by remotely deploying non-destructive inspection (NDI) sensors and acquiring, processing, and storing inspection data. Carnegie Mellon University studie...
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Directory of Open Access Journals (Sweden)
GEAMBASU Gabriel George
2017-05-01
Full Text Available The paper presents the maintenance process that is done on an airplane, at a certain period of time, or after a number of flight hours or cycles and describes the checks performed behind each inspection. The first part of research describes the aircraft maintenance process that has to be done after an updated maintenance manual according with aircraft type, followed by a short introduction about maintenance hangar. The second part of the paper presents a hangar design with a foldable roof and walls, which can be folded or extended, over an airplane when a maintenance process is done, or depending on weather condition.
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Directory of Open Access Journals (Sweden)
Widowati
2012-07-01
Full Text Available The applicability of parameter varying reduced order controllers to aircraft model is proposed. The generalization of the balanced singular perturbation method of linear time invariant (LTI system is used to reduce the order of linear parameter varying (LPV system. Based on the reduced order model the low-order LPV controller is designed by using synthesis technique. The performance of the reduced order controller is examined by applying it to lateral-directional control of aircraft model having 20th order. Furthermore, the time responses of the closed loop system with reduced order LPV controllers and reduced order LTI controller is compared. From the simulation results, the 8th order LPV controller can maintain stability and to provide the same level of closed-loop systems performance as the full-order LPV controller. It is different with the reduced-order LTI controller that cannot maintain stability and performance for all allowable parameter trajectories.
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Aircraft engine pollution reduction.
Rudey, R. A.
1972-01-01
The effect of engine operation on the types and levels of the major aircraft engine pollutants is described and the major factors governing the formation of these pollutants during the burning of hydrocarbon fuel are discussed. Methods which are being explored to reduce these pollutants are discussed and their application to several experimental research programs are pointed out. Results showing significant reductions in the levels of carbon monoxide, unburned hydrocarbons, and oxides of nitrogen obtained from experimental combustion research programs are presented and discussed to point out potential application to aircraft engines. An experimental program designed to develop and demonstrate these and other advanced, low pollution combustor design methods is described. Results that have been obtained to date indicate considerable promise for reducing advanced engine exhaust pollutants to levels significantly below current engines.
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The research of optical windows used in aircraft sensor systems
International Nuclear Information System (INIS)
Zhou Feng; Li Yan; Tang Tian-Jin
2012-01-01
The optical windows used in aircrafts protect their imaging sensors from environmental effects. Considering the imaging performance, flat surfaces are traditionally used in the design of optical windows. For aircrafts operating at high speeds, the optical windows should be relatively aerodynamic, but a flat optical window may introduce unacceptably high drag to the airframes. The linear scanning infrared sensors used in aircrafts with, respectively, a 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)
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Plotting the Flight Envelope of an Unmanned Aircraft System Air Vehicle
Directory of Open Access Journals (Sweden)
Glīzde Nikolajs
2017-08-01
Full Text Available The research is focused on the development of an Unmanned Aircraft System. One of the design process steps in the preliminary design phase is the calculation of the flight envelope for the Unmanned Aircraft System air vehicle. The results obtained will be used in the further design process. A flight envelope determines the minimum requirements for the object in Certification Specifications. The present situation does not impose any Certification Specification requirements for the class of the Unmanned Aircraft System under the development of the general European Union trend defined in the road map for the implementation of the Unmanned Aircraft System. However, operation in common European Aerospace imposes the necessity for regulations for micro class systems as well.
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AIRTV: Broadband Direct to Aircraft
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
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Turboelectric Aircraft Drive Key Performance Parameters and Functional Requirements
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.
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Aeroelastic Loads Modeling for Composite Aircraft Design Support
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
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Indian Academy of Sciences (India)
With the evolution of high performance modern aircraft and spiraling developmental and experimental costs, the importance of flight validated databases for flight control design applications and for flight simulators has increased significantly in the recent past. Ground-based and in-flight simulators are increasingly used not ...
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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
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A strategic planning methodology for aircraft redesign
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
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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
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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.
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49 CFR 173.172 - Aircraft hydraulic power unit fuel tank.
2010-10-01
... 49 Transportation 2 2010-10-01 2010-10-01 false Aircraft hydraulic power unit fuel tank. 173.172... Class 1 and Class 7 § 173.172 Aircraft hydraulic power unit fuel tank. Aircraft hydraulic power unit fuel tanks containing a mixture of anhydrous hydrazine and monomethyl hydrazine (M86 fuel) and designed...
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Hydrogen aircraft and airport safety
International Nuclear Information System (INIS)
Schmidtchen, U.; Behrend, E.; Pohl, H.-W.; Rostek, N.
1997-01-01
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 m 3 LH 2 . 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)
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Energy Technology Data Exchange (ETDEWEB)
Ruffles, P C
1989-01-01
Configurational design and thermodynamic performance gain trends are projected into the next 50 years, in view of the growing interest of aircraft manufacturers in both larger and more efficient high-bypass turbofan engines for subsonic flight and variable cycle engines for supersonic flight. Ceramic- and metal-matrix composites are envisioned as the key to achievement of turbine inlet temperatures 300 C higher than the 1400 C which is characteristic of the state-of-the-art, with the requisite high stiffness, strength, and low density. Such fiber-reinforced materials can be readily tailored to furnish greatest strength in a specific direction of loading. Large, low-density engines are critical elements of future 1000-seat aircraft.
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Fundamentals of aircraft and rocket propulsion
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...
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Aurora Flight Sciences' Perseus B Remotely Piloted Aircraft in Flight
1998-01-01
A long, slender wing and a pusher propeller at the rear characterize the Perseus B remotely piloted research aircraft, seen here during a test flight in June 1998. Perseus B is a remotely piloted aircraft developed as a design-performance testbed under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) project. Perseus is one of several flight vehicles involved in the ERAST project. A piston engine, propeller-powered aircraft, Perseus was designed and built by Aurora Flight Sciences Corporation, Manassas, Virginia. The objectives of Perseus B's ERAST flight tests have been to reach and maintain horizontal flight above altitudes of 60,000 feet and demonstrate the capability to fly missions lasting from 8 to 24 hours, depending on payload and altitude requirements. The Perseus B aircraft established an unofficial altitude record for a single-engine, propeller-driven, remotely piloted aircraft on June 27, 1998. It reached an altitude of 60,280 feet. In 1999, several modifications were made to the Perseus aircraft including engine, avionics, and flight-control-system improvements. These improvements were evaluated in a series of operational readiness and test missions at the Dryden Flight Research Center, Edwards, California. Perseus is a high-wing monoplane with a conventional tail design. Its narrow, straight, high-aspect-ratio wing is mounted atop the fuselage. The aircraft is pusher-designed with the propeller mounted in the rear. This design allows for interchangeable scientific-instrument payloads to be placed in the forward fuselage. The design also allows for unobstructed airflow to the sensors and other devices mounted in the payload compartment. The Perseus B that underwent test and development in 1999 was the third generation of the Perseus design, which began with the Perseus Proof-Of-Concept aircraft. Perseus was initially developed as part of NASA's Small High-Altitude Science Aircraft (SHASA) program, which later evolved into the ERAST
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Aircraft vulnerability analysis by modeling and simulation
Willers, Cornelius J.; Willers, Maria S.; de Waal, Alta
2014-10-01
Infrared missiles pose a significant threat to civilian and military aviation. ManPADS missiles are especially dangerous in the hands of rogue and undisciplined forces. Yet, not all the launched missiles hit their targets; the miss being either attributable to misuse of the weapon or to missile performance restrictions. This paper analyses some of the factors affecting aircraft vulnerability and demonstrates a structured analysis of the risk and aircraft vulnerability problem. The aircraft-missile engagement is a complex series of events, many of which are only partially understood. Aircraft and missile designers focus on the optimal design and performance of their respective systems, often testing only in a limited set of scenarios. Most missiles react to the contrast intensity, but the variability of the background is rarely considered. Finally, the vulnerability of the aircraft depends jointly on the missile's performance and the doctrine governing the missile's launch. These factors are considered in a holistic investigation. The view direction, altitude, time of day, sun position, latitude/longitude and terrain determine the background against which the aircraft is observed. Especially high gradients in sky radiance occur around the sun and on the horizon. This paper considers uncluttered background scenes (uniform terrain and clear sky) and presents examples of background radiance at all view angles across a sphere around the sensor. A detailed geometrical and spatially distributed radiometric model is used to model the aircraft. This model provides the signature at all possible view angles across the sphere around the aircraft. The signature is determined in absolute terms (no background) and in contrast terms (with background). It is shown that the background significantly affects the contrast signature as observed by the missile sensor. A simplified missile model is constructed by defining the thrust and mass profiles, maximum seeker tracking rate, maximum
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Lightweight, fire-retardant, crashworthy aircraft seat cushioning
Haslim, Leonard A.; Mcdonough, Paul T.
1991-01-01
A two page discussion of non-aerospace seating applications and the design of NASA's safety seat cushioning (SSC) is presented. The SSC was designed for both safety and comfort in order to replace polyurethane cushioning which is flammable and produces lethal fumes upon combustion. The SSC is composed of advanced fabric reinforced composites and is lightweight, fire-retardent, and crashworthy. The seat design consists of central elliptical tubular spring supports made of fire-resistant and fatigue-durable composites surrounded by a fire-blocking sheath. The cushioning is made crashworthy by incorporating energy-absorbing, viscoelastic layers between the nested, elliptical-hoop springs. The design is intended to provide comfortable seating that meets aircraft-loading requirements without using the conventional polyurethane materials. The designs of an aircraft seat and structural components of the SSC are also presented.
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Subsonic Ultra Green Aircraft Research: Phase 2. Volume 2; Hybrid Electric Design Exploration
Bradley, Marty K.; Droney, Christopher K.
2015-01-01
This report summarizes the hybrid electric concept design, analysis, and modeling work accomplished by the Boeing Subsonic Ultra Green Aircraft Research (SUGAR) team, consisting of Boeing Research and Technology, Boeing Commercial Airplanes, General Electric, and Georgia Tech.Performance and sizing tasks were conducted for hybrid electric versions of a conventional tube-and-wing aircraft and a hybrid wing body. The high wing Truss Braced Wing (TBW) SUGAR Volt was updated based on results from the TBW work (documented separately) and new engine performance models. Energy cost and acoustic analyses were conducted and technology roadmaps were updated for hybrid electric and battery technology. NOx emissions were calculated for landing and takeoff (LTO) and cruise. NPSS models were developed for hybrid electric components and tested using an integrated analysis of superconducting and non-superconducting hybrid electric engines. The hybrid electric SUGAR Volt was shown to produce significant emissions and fuel burn reductions beyond those achieved by the conventionally powered SUGAR High and was able to meet the NASA goals for fuel burn. Total energy utilization was not decreased but reduced energy cost can be achieved for some scenarios. The team was not able to identify a technology development path to meet NASA's noise goals
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Bennett, Ian Graham
Automatic Dependent Surveillance-Broadcast (ADS-B) is quickly becoming the new standard for more efficient air traffic control, but as a satellite/ground-based hybrid system it faces limitations on its usefulness over oceans and remote areas. Tracking of aircraft from space presents many challenges that if overcome will greatly increase the safety and efficiency of commercial air travel in these areas. This thesis presents work performed to develop a flight-ready ADS-B receiver payload for the CanX-7 technology demonstration satellite. Work presented includes a simulation of payload performance and coverage area, the design and testing of a single-feed circularly polarized L-band antenna, the design of software to control the payload and manage its data, and verification of the performance of the hardware prior to integration with the satellite and launch. Also included is a short overview of results from the seven-month aircraft tracking campaign conducted with the spacecraft.
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Enabling alternate fuels for commercial aircraft
Daggett, D.
2010-01-01
The following reports on the past four years of work to examine the feasibility, sustainability and economic viability of developing a renewable, greenhouse-gas-neutral, liquid biofuel for commercial aircraft. The sharp increase in environmental concerns, such as global warming, as well as the volatile price fluctuations of fossil fuels, has ignited a search for alternative transportation fuels. However, commercial aircraft can not use present alternative fuels that are designed for ground...
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NPP post-accident monitoring system based on unmanned aircraft vehicle:concept, design principles
International Nuclear Information System (INIS)
Sachenko, A.A.; Kochan, V.V.; Kharchenko, V.S.; Yanovskij, M.Eh.; Yastrebenetskij, M.A.; Fesenko, G.V.
2016-01-01
The paper presents a concept of designing the post-accident system for monitoring the equipment and territory of nuclear power plant after a severe accident based on unmanned aircraft vehicle (UAVs). Wired power and communications networks are found out as the most vulnerable ones during the accident monitoring, and informativity, reliability and veracity are recognized as system basic parameters. It is proposed to equip measurement and control modules with backup wireless communication channels and deploy the repeaters network based on UAVs to ensure the informativity. Modules possess the backup power battery, and repeaters appear in the appropriate places after the accident to provide the survivability. Moreover, an optimization of UAVs' location is proposed according to the minimum energy consumption criterion. To ensure the veracity, it is expected to design the noise-immune protocol for message exchange and archiving and self-diagnostics of all system components
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Alternate aircraft fuels prospects and operational implications
Witcofski, R. D.
1977-01-01
The paper discusses NASA studies of the potentials of coal-derived aviation fuels, specifically synthetic aviation kerosene, liquid methane, and liquid hydrogen. Topics include areas of fuel production, air terminal requirements for aircraft fueling (for liquid hydrogen only), and the performance characteristics of aircraft designed to utilize alternate fuels. Energy requirements associated with the production of each of the three selected fuels are determined, and fuel prices are estimated. Subsonic commercial air transports using liquid hydrogen fuel have been analyzed, and their performance and the performance of aircraft which use commercial aviation kerosene are compared. Environmental and safety issues are considered.
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Richardson, J.; Labbe, M.; Belala, Y.; Leduc, Vincent
1994-01-01
The requirement for improving aircraft utilization and responsiveness in airlift operations has been recognized for quite some time by the Canadian Forces. To date, the utilization of scarce airlift resources has been planned mainly through the employment of manpower-intensive manual methods in combination with the expertise of highly qualified personnel. In this paper, we address the problem of facilitating the load planning process for military aircraft cargo planes through the development of a computer-based system. We introduce TALBAS (Transport Aircraft Loading and BAlancing System), a knowledge-based system designed to assist personnel involved in preparing valid load plans for the C130 Hercules aircraft. The main features of this system which are accessible through a convivial graphical user interface, consists of the automatic generation of valid cargo arrangements given a list of items to be transported, the user-definition of load plans and the automatic validation of such load plans.
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Lampl, Thomas; Muschkorgel, Sandra; Hornung, Mirko;
2018-01-01
The trend towards More-Electric Aircraft (MEA) and the introduction of new system technologies lead to considerable changes at the system level of commercial transport aircraft. Because the number of systems and power requirements are increasing, the consideration and integration of aircraft systems in early aircraft design phases is important. The objective of this contribution is to develop a characteristic flight mission with modelled aircraft systems to estimate the secondary power requir...
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Army-NASA aircrew/aircraft integration program (A3I) software detailed design document, phase 3
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.
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Aging Military Aircraft Landscape : A Case for End-of-Life Fleet Optimization
Newcamp, J.M.; Verhagen, W.J.C.; Curran, Ricky
2016-01-01
Military aircraft fleets are continuing to age despite increased structural integrity concerns and rising maintenance costs. Aircraft are not being replaced or retired in large numbers but are instead having their lives extended beyond their original design service lives. Because aging aircraft cost
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Aerodynamics/ACEE: Aircraft energy efficiency
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.
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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.
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Computational Fluid Dynamics of Whole-Body Aircraft
Agarwal, Ramesh
1999-01-01
The current state of the art in computational aerodynamics for whole-body aircraft flowfield simulations is described. Recent advances in geometry modeling, surface and volume grid generation, and flow simulation algorithms have led to accurate flowfield predictions for increasingly complex and realistic configurations. As a result, computational aerodynamics has emerged as a crucial enabling technology for the design and development of flight vehicles. Examples illustrating the current capability for the prediction of transport and fighter aircraft flowfields are presented. Unfortunately, accurate modeling of turbulence remains a major difficulty in the analysis of viscosity-dominated flows. In the future, inverse design methods, multidisciplinary design optimization methods, artificial intelligence technology, and massively parallel computer technology will be incorporated into computational aerodynamics, opening up greater opportunities for improved product design at substantially reduced costs.
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Study of LH2 fueled subsonic passenger transport aircraft
Brewer, G. D.; Morris, R. E.
1976-01-01
The potential of using liquid hydrogen as fuel in subsonic transport aircraft was investigated to explore an expanded matrix of passenger aircraft sizes. Aircraft capable of carrying 130 passengers 2,780 km (1500 n.mi.); 200 passengers 5,560 km (3000 n.mi.); and 400 passengers on a 9,265 km (5000 n.mi.) radius mission, were designed parametrically. Both liquid hydrogen and conventionally fueled versions were generated for each payload/range in order that comparisons could be made. Aircraft in each mission category were compared on the basis of weight, size, cost, energy utilization, and noise.
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Experiments Result in Safer, Spin-Resistant Aircraft
2014-01-01
The General Aviation Spin Program at Langley Research Center devised the first-of-their-kind guidelines for designing more spin-resistant aircraft. Thanks to NASA's contributions, the Federal Aviation Administration introduced the Part 23 spin-resistance standard in 1991. Los Angeles-based ICON Aircraft has now manufactured a new plane for consumer recreational flying that meets the complete set of criteria specified for Part 23 testing.
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International Nuclear Information System (INIS)
Fritsch, H.
1985-01-01
The bibliography includes 48 quotations, up to the year 1983, on the following issues: Experiments and computational methods. Design load for the dimensioning of reinforced concrete buildings and components with respect to the dynamic load in the event of an aircraft crash. (orig./HP) [de
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Generic regional aircraft flying qualities for the approach and landing task
Gautrey, Jim
1997-01-01
Many changes have occurred in the past 20 years in aircraft manufacture and development. New technologies have appeared, spanning the entire aircraft design environment, such as new production methods, new materials and new avionics systems. These new methods have been developed for two reasons. For military aircraft, they have arisen through the need to improve performance. However, for civil aircraft they have arisen through the need to reduce the overall cost. This report co...
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Aircraft Impact Assessment of APR1400 Reactor Containment Building
International Nuclear Information System (INIS)
Moon, Il Hwan; Kim, Do Yeon; Kim, Jae Hee; Kim, Sang Yun
2011-01-01
The implementation of a protection to withstand aircraft impact on safety-related structures and systems is basically based on a probabilistic evaluation for each site, if the licensing body doesn't require a deterministic approach. Existing nuclear power plants in Korea were designed based on the probabilistic approach, and the aircraft impact hazard remained less than a probability of 10 -7 . However, a man-made aircraft impact have been considered as a possible external accident for the nuclear power plant. New plant designs that are to be constructed in the U.S. after July 2009 must consider the effect of impact from a large commercial aircraft according to the requirements of 10 CFR 50.150. Especially, Reactor Containment Building (RCB) housing the safety-related equipment and fuels should be protected safely against aircraft crash without perforation and scabbing failure of external wall. APR1400 RCB is constructed as a prestressed concrete containment vessel (PCCV) which is surrounded by the auxiliary building housing additional safety-related equipment and other systems. In this study, the aircraft impact analyses for the RCB are carried out using Riera forcing function and aircraft model. Considered external wall thickness is 4 ft 6 in. for the cylindrical wall and 4 ft for the dome. Actual strengths of concrete and steel are considered as the material properties. For these analyses, the dynamic increment factor and concrete aging effect are considered in accordance with NEI 07-13(2011)
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Energy Technology Data Exchange (ETDEWEB)
Pfister, A.; Goossen, C.; Coogler, K.; Gorgemans, J. [Westinghouse Electric Company LLC, 1000 Westinghouse Drive, Cranberry Township, PA 16066 (United States)
2012-07-01
Both the International Atomic Energy Agency (IAEA) and the U.S. Nuclear Regulatory Commission (NRC) require existing and new nuclear power plants to conduct plant assessments to demonstrate the unit's ability to withstand external hazards. The events that occurred at the Fukushima-Dai-ichi nuclear power station demonstrated the importance of designing a nuclear power plant with the ability to protect the plant against extreme external hazards. The innovative design of the AP1000{sup R} nuclear power plant provides unparalleled protection against catastrophic external events which can lead to extensive infrastructure damage and place the plant in an extended abnormal situation. The AP1000 plant is an 1100-MWe pressurized water reactor with passive safety features and extensive plant simplifications that enhance construction, operation, maintenance and safety. The plant's compact safety related footprint and protection provided by its robust nuclear island structures prevent significant damage to systems, structures, and components required to safely shutdown the plant and maintain core and spent fuel pool cooling and containment integrity following extreme external events. The AP1000 nuclear power plant has been extensively analyzed and reviewed to demonstrate that it's nuclear island design and plant layout provide protection against both design basis and extreme beyond design basis external hazards such as extreme seismic events, external flooding that exceeds the maximum probable flood limit, and malicious aircraft impact. The AP1000 nuclear power plant uses fail safe passive features to mitigate design basis accidents. The passive safety systems are designed to function without safety-grade support systems (such as AC power, component cooling water, service water, compressed air or HVAC). The plant has been designed to protect systems, structures, and components critical to placing the reactor in a safe shutdown condition within the steel
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Hydrogen Fuel System Design Trades for High-Altitude Long-Endurance Remotely- Operated Aircraft
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.
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Advanced organic composite materials for aircraft structures: Future program
1987-01-01
Revolutionary advances in structural materials have been responsible for revolutionary changes in all fields of engineering. These advances have had and are still having a significant impact on aircraft design and performance. Composites are engineered materials. Their properties are tailored through the use of a mix or blend of different constituents to maximize selected properties of strength and/or stiffness at reduced weights. More than 20 years have passed since the potentials of filamentary composite materials were identified. During the 1970s much lower cost carbon filaments became a reality and gradually designers turned from boron to carbon composites. Despite progress in this field, filamentary composites still have significant unfulfilled potential for increasing aircraft productivity; the rendering of advanced organic composite materials into production aircraft structures was disappointingly slow. Why this is and research and technology development actions that will assist in accelerating the application of advanced organic composites to production aircraft is discussed.
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Perseus A High Altitude Remotely Piloted Aircraft being Towed in Flight
1994-01-01
Perseus A, a remotely piloted, high-altitude research vehicle designed by Aurora Flight Sciences Corp., takes off from Rogers Dry Lake at the Dryden Flight Research Center, Edwards, California. The Perseus was towed into the air by a ground vehicle. At about 700 ft. the aircraft was released and the engine turned the propeller to take the plane to its desired altitude. Perseus B is a remotely piloted aircraft developed as a design-performance testbed under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) project. Perseus is one of several flight vehicles involved in the ERAST project. A piston engine, propeller-powered aircraft, Perseus was designed and built by Aurora Flight Sciences Corporation, Manassas, Virginia. The objectives of Perseus B's ERAST flight tests have been to reach and maintain horizontal flight above altitudes of 60,000 feet and demonstrate the capability to fly missions lasting from 8 to 24 hours, depending on payload and altitude requirements. The Perseus B aircraft established an unofficial altitude record for a single-engine, propeller-driven, remotely piloted aircraft on June 27, 1998. It reached an altitude of 60,280 feet. In 1999, several modifications were made to the Perseus aircraft including engine, avionics, and flight-control-system improvements. These improvements were evaluated in a series of operational readiness and test missions at the Dryden Flight Research Center, Edwards, California. Perseus is a high-wing monoplane with a conventional tail design. Its narrow, straight, high-aspect-ratio wing is mounted atop the fuselage. The aircraft is pusher-designed with the propeller mounted in the rear. This design allows for interchangeable scientific-instrument payloads to be placed in the forward fuselage. The design also allows for unobstructed airflow to the sensors and other devices mounted in the payload compartment. The Perseus B that underwent test and development in 1999 was the third generation of the
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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.
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Development of Nonlinear Flight Mechanical Model of High Aspect Ratio Light Utility Aircraft
Bahri, S.; Sasongko, R. A.
2018-04-01
The implementation of Flight Control Law (FCL) for Aircraft Electronic Flight Control System (EFCS) aims to reduce pilot workload, while can also enhance the control performance during missions that require long endurance flight and high accuracy maneuver. In the development of FCL, a quantitative representation of the aircraft dynamics is needed for describing the aircraft dynamics characteristic and for becoming the basis of the FCL design. Hence, a 6 Degree of Freedom nonlinear model of a light utility aircraft dynamics, also called the nonlinear Flight Mechanical Model (FMM), is constructed. This paper shows the construction of FMM from mathematical formulation, the architecture design of FMM, the trimming process and simulations. The verification of FMM is done by analysis of aircraft behaviour in selected trimmed conditions.
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PREDICTIVE ASSESSMENT OF AN AIRCRAFT STRUCTURE BEHAVIOUR FOR PASSENGER AND CREW SECURITY
Directory of Open Access Journals (Sweden)
Daniela BARAN
2009-12-01
Full Text Available In the aerospace industry one of the most important requirements in the aircraft design andoperation is the high level of fiability under various atmosphere and environmental conditions. Thedesign and validation of such a system is a great challenge. It must meet several requirements suchas: high resistence, low weight and a small occupied volume. The stresses that occur during theaircraft operation are extremely complex, being the result of the interaction of differentsystems.Consequently, in order to obtain an optimal design of the whole system, the design, testingand operating processes require a combination of laborious analysis and experimental data. As upto 90% of the structure failures are du to the fatigue, high performance methods of fatigue analysisare needed to estimate the aircraft ressources. These methods must enable a precise determinationof the static and dynamic strains inder to correctly estimate the aircraft ressource. The projectproposes an approach of some aspects of the aircraft/ aircraft subassemblies simulation and testingand develop o calculation methodology of experimental data and high performance numericmethods integration in order to establish the ressource.
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Shimmy of Aircraft Main Landing Gears
Besselink, I.J.M.
2000-01-01
The landing gear is an important aircraft system, which has to meet many different design requirements. It is a highly loaded structure, which is designed for minimum weight. Shimmy is a dynamic instability of the landing gear, which is caused by the interaction of the dynamic behaviour of the
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Mission Analysis and Aircraft Sizing of a Hybrid-Electric Regional Aircraft
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.
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Longitudinal control of aircraft dynamics based on optimization of PID parameters
Deepa, S. N.; Sudha, G.
2016-03-01
Recent years many flight control systems and industries are employing PID controllers to improve the dynamic behavior of the characteristics. In this paper, PID controller is developed to improve the stability and performance of general aviation aircraft system. Designing the optimum PID controller parameters for a pitch control aircraft is important in expanding the flight safety envelope. Mathematical model is developed to describe the longitudinal pitch control of an aircraft. The PID controller is designed based on the dynamic modeling of an aircraft system. Different tuning methods namely Zeigler-Nichols method (ZN), Modified Zeigler-Nichols method, Tyreus-Luyben tuning, Astrom-Hagglund tuning methods are employed. The time domain specifications of different tuning methods are compared to obtain the optimum parameters value. The results prove that PID controller tuned by Zeigler-Nichols for aircraft pitch control dynamics is better in stability and performance in all conditions. Future research work of obtaining optimum PID controller parameters using artificial intelligence techniques should be carried out.
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Satellite images to aircraft in flight. [GEOS image transmission feasibility analysis
Camp, D.; Luers, J. K.; Kadlec, P. W.
1977-01-01
A study has been initiated to evaluate the feasibility of transmitting selected GOES images to aircraft in flight. Pertinent observations that could be made from satellite images on board aircraft include jet stream activity, cloud/wind motion, cloud temperatures, tropical storm activity, and location of severe weather. The basic features of the Satellite Aircraft Flight Environment System (SAFES) are described. This system uses East GOES and West GOES satellite images, which are interpreted, enhanced, and then retransmitted to designated aircraft.
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ACSYNT inner loop flight control design study
Bortins, Richard; Sorensen, John A.
1993-01-01
The NASA Ames Research Center developed the Aircraft Synthesis (ACSYNT) computer program to synthesize conceptual future aircraft designs and to evaluate critical performance metrics early in the design process before significant resources are committed and cost decisions made. ACSYNT uses steady-state performance metrics, such as aircraft range, payload, and fuel consumption, and static performance metrics, such as the control authority required for the takeoff rotation and for landing with an engine out, to evaluate conceptual aircraft designs. It can also optimize designs with respect to selected criteria and constraints. Many modern aircraft have stability provided by the flight control system rather than by the airframe. This may allow the aircraft designer to increase combat agility, or decrease trim drag, for increased range and payload. This strategy requires concurrent design of the airframe and the flight control system, making trade-offs of performance and dynamics during the earliest stages of design. ACSYNT presently lacks means to implement flight control system designs but research is being done to add methods for predicting rotational degrees of freedom and control effector performance. A software module to compute and analyze the dynamics of the aircraft and to compute feedback gains and analyze closed loop dynamics is required. The data gained from these analyses can then be fed back to the aircraft design process so that the effects of the flight control system and the airframe on aircraft performance can be included as design metrics. This report presents results of a feasibility study and the initial design work to add an inner loop flight control system (ILFCS) design capability to the stability and control module in ACSYNT. The overall objective is to provide a capability for concurrent design of the aircraft and its flight control system, and enable concept designers to improve performance by exploiting the interrelationships between
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Evaluation of all-electric secondary power for transport aircraft
Murray, W. E.; Feiner, L. J.; Flores, R. R.
1992-01-01
This report covers a study by Douglas Aircraft Company (DAC) of electrical power systems for advanced transport aircraft based upon an all-electric design concept. The concept would eliminate distributed hydraulic and pneumatic secondary power systems, and feature an expanded secondary electrical power system redesigned to supply power to the loads customarily supplied by hydraulic or pneumatic power. The initial study was based on an advanced 20-kHz electrical power transmission and distribution system, using a system architecture supplied by NASA-Lewis Research Center for twin-engine aircraft with many advanced power conversion concepts. NASA-LeRC later requested DAC to refocus the study on 400-Hz secondary power distribution. Subsequent work was based on a three-engine MD-11 aircraft, selected by DAC as a baseline system design that would provide data for the comparative cost/benefit analysis. The study concluded that the 20-kHz concept produced many expected benefits, and that the all-electric trijet weight savings on hardware redesign would be 2,304 pounds plus a 2.1-percent fuel reduction and resized for a total weight reduction of 11,000 pounds. Cost reductions for a fleet of 800 aircraft in a 15-year production program were estimated at $76.71 million for RDT&E; $2.74 million per aircrat for production; $9.84 million for nonrecurring expenses; $120,000 per aircraft for product support; and $300,000 per aircraft per year for operating and maintenance costs, giving a present value of $1.914 billion saved or a future value of $10.496 billion saved.
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Feasibility study for a microwave-powered ozone sniffer aircraft. B.S. Thesis
Botros, David F.; Cody, Charlotte K.; Forden, Noah P.; Helsing, Martin A.; Jutras, Thomas H.; Kim, Dohoon; Labarre, Christopher; Odin, Ethan M.; Sandler, Scott B.
1990-01-01
The preliminary design of a high-altitude, remotely-piloted, atmospheric-sampling aircraft powered by microwave energy beamed from ground-based antenna was completed. The vehicle has a gross weight of 6720 pounds and is sized to carry a 1000 pound payload at an altitude of 100,000 feet. The underside of the wing serves as the surface of a rectenna designed to receive microwave energy at a power density of 700 watts per square meter and the wing has a planform area of 3634 square feet to absorb the required power at an optimum Mach number M = 0.44. The aircraft utilizes a horizontal tail and a canard for longitudinal control and to enhance the structural rigidity of the twin fuselage configuration. The wing structure is designed to withstand a gust-induced load factor n = 3 at cruise altitude but the low-wing loading of the aircraft makes it very sensitive to gusts at low altitudes, which may induce load factors in excess of 20. A structural load alleviation system is therefore proposed to limit actual loads to the designed structural limit. Losses will require transmitted power on the order of megawatts to be radiated to the aircraft from the ground station, presenting environmental problems. Since the transmitting antenna would have a diameter of several hundred feet, it would not be readily transportable, so we propose that a single antenna be constructed at a site from which the aircraft is flown. The aircraft would be towed aloft to an initial altitude at which the microwave power would be utilized. The aircraft would climb to cruise altitude in a spiral flight path and orbit the transmitter in a gentle turn.
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An Overview of NASA's Subsonic Research Aircraft Testbed (SCRAT)
Baumann, Ethan; Hernandez, Joe; Ruhf, John C.
2013-01-01
National Aeronautics and Space Administration Dryden Flight Research Center acquired a Gulfstream III (GIII) aircraft to serve as a testbed for aeronautics flight research experiments. The aircraft is referred to as SCRAT, which stands for SubsoniC Research Aircraft Testbed. The aircraft's mission is to perform aeronautics research; more specifically raising the Technology Readiness Level (TRL) of advanced technologies through flight demonstrations and gathering high-quality research data suitable for verifying the technologies, and validating design and analysis tools. The SCRAT has the ability to conduct a range of flight research experiments throughout a transport class aircraft's flight envelope. Experiments ranging from flight-testing of a new aircraft system or sensor to those requiring structural and aerodynamic modifications to the aircraft can be accomplished. The aircraft has been modified to include an instrumentation system and sensors necessary to conduct flight research experiments along with a telemetry capability. An instrumentation power distribution system was installed to accommodate the instrumentation system and future experiments. An engineering simulation of the SCRAT has been developed to aid in integrating research experiments. A series of baseline aircraft characterization flights has been flown that gathered flight data to aid in developing and integrating future research experiments. This paper describes the SCRAT's research systems and capabilities.
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Resistance ability evaluation of safety-related structures for the simulated aircraft accident
Energy Technology Data Exchange (ETDEWEB)
Kim, Young Jin; Kim, Sung Woon; Choi, Jang Kyu [Daewoo E and C Co., Ltd., Suwon (Korea, Republic of)] (and others)
2003-03-15
Aircraft accidents on nuclear safety-related structures can cause severe damage to the safety of NPP(Nuclear Power Plant)s. To assess the safety of nuclear safety-related structures, the local damage and the dynamic response of global structures should be investigated together. This study have compared several local damage assessment formulas suggested for aircraft as an impactor, and have set the assessment system of local damage for impact-proof design of NPP containment buildings. And the local damage of nuclear safety-related structures in operation in Korea for commercial aircraft as impactor have been estimated. Impact load-time functions of the aircraft crash have been decided to assessment the safety of nuclear safety-related structures against the intentional colliding of commercial aircraft. Boeing 747 and Boeing 767 is selected as target aircraft based on the operation frequencies and weights. Comparison of the fire analysis methods showed that the method considering heat convection and radiation is adequate for the temperature analysis of the aircraft fuel fire. Finally, the study covered the analysis of the major structural drawings and design drawings with which three-dimensional finite element model analysis is expected to be performed.
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Aircraft Wiring Support Equipment Integration Laboratory (AWSEIL)
Federal Laboratory Consortium — Purpose:The Aircraft Wiring Support Equipment Integration Laboratory (AWSEIL) provides a variety of research, design engineering and prototype fabrication services...
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Engine-propeller power plant aircraft community noise reduction key methods
Moshkov P., A.; Samokhin V., F.; Yakovlev A., A.
2018-04-01
Basic methods of aircraft-type flying vehicle engine-propeller power plant noise reduction were considered including single different-structure-and-arrangement propellers and piston engines. On the basis of a semiempirical model the expressions for blade diameter and number effect evaluation upon propeller noise tone components under thrust constancy condition were proposed. Acoustic tests performed at Moscow Aviation institute airfield on the whole qualitatively proved the obtained ratios. As an example of noise and detectability reduction provision a design-and-experimental estimation of propeller diameter effect upon unmanned aircraft audibility boundaries was performed. Future investigation ways were stated to solve a low-noise power plant design problem for light aircraft and unmanned aerial vehicles.
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Database on aircraft accidents
International Nuclear Information System (INIS)
Nishio, Masahide; Koriyama, Tamio
2012-09-01
The Reactor Safety Subcommittee in the Nuclear Safety and Preservation Committee published the report 'The criteria on assessment of probability of aircraft crash into light water reactor facilities' as the standard method for evaluating probability of aircraft crash into nuclear reactor facilities in July 2002. In response to the report, Japan Nuclear Energy Safety Organization has been collecting open information on aircraft accidents of commercial airplanes, self-defense force (SDF) airplanes and US force airplanes every year since 2003, sorting out them and developing the database of aircraft accidents for latest 20 years to evaluate probability of aircraft crash into nuclear reactor facilities. This year, the database was revised by adding aircraft accidents in 2010 to the existing database and deleting aircraft accidents in 1991 from it, resulting in development of the revised 2011 database for latest 20 years from 1991 to 2010. Furthermore, the flight information on commercial aircrafts was also collected to develop the flight database for latest 20 years from 1991 to 2010 to evaluate probability of aircraft crash into reactor facilities. The method for developing the database of aircraft accidents to evaluate probability of aircraft crash into reactor facilities is based on the report 'The criteria on assessment of probability of aircraft crash into light water reactor facilities' described above. The 2011 revised database for latest 20 years from 1991 to 2010 shows the followings. The trend of the 2011 database changes little as compared to the last year's one. (1) The data of commercial aircraft accidents is based on 'Aircraft accident investigation reports of Japan transport safety board' of Ministry of Land, Infrastructure, Transport and Tourism. 4 large fixed-wing aircraft accidents, 58 small fixed-wing aircraft accidents, 5 large bladed aircraft accidents and 114 small bladed aircraft accidents occurred. The relevant accidents for evaluating
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14 CFR 21.6 - Manufacture of new aircraft, aircraft engines, and propellers.
2010-01-01
... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Manufacture of new aircraft, aircraft... Manufacture of new aircraft, aircraft engines, and propellers. (a) Except as specified in paragraphs (b) and (c) of this section, no person may manufacture a new aircraft, aircraft engine, or propeller based on...
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Propulsion Study for Small Transport Aircraft Technology (STAT)
Gill, J. C.; Earle, R. V.; Staton, D. V.; Stolp, P. C.; Huelster, D. S.; Zolezzi, B. A.
1980-01-01
Propulsion requirements were determined for 0.5 and 0.7 Mach aircraft. Sensitivity studies were conducted on both these aircraft to determine parametrically the influence of propulsion characteristics on aircraft size and direct operating cost (DOC). Candidate technology elements and design features were identified and parametric studies conducted to select the STAT advanced engine cycle. Trade off studies were conducted to determine those advanced technologies and design features that would offer a reduction in DOC for operation of the STAT engines. These features were incorporated in the two STAT engines. A benefit assessment was conducted comparing the STAT engines to current technology engines of the same power and to 1985 derivatives of the current technology engines. Research and development programs were recommended as part of an overall technology development plan to ensure that full commercial development of the STAT engines could be initiated in 1988.
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Database on aircraft accidents
International Nuclear Information System (INIS)
Nishio, Masahide; Koriyama, Tamio
2013-11-01
The Reactor Safety Subcommittee in the Nuclear Safety and Preservation Committee published 'The criteria on assessment of probability of aircraft crash into light water reactor facilities' as the standard method for evaluating probability of aircraft crash into nuclear reactor facilities in July 2002. In response to this issue, Japan Nuclear Energy Safety Organization has been collecting open information on aircraft accidents of commercial airplanes, self-defense force (SDF) airplanes and US force airplanes every year since 2003, sorting out them and developing the database of aircraft accidents for the latest 20 years to evaluate probability of aircraft crash into nuclear reactor facilities. In this report the database was revised by adding aircraft accidents in 2011 to the existing database and deleting aircraft accidents in 1991 from it, resulting in development of the revised 2012 database for the latest 20 years from 1992 to 2011. Furthermore, the flight information on commercial aircrafts was also collected to develop the flight database for the latest 20 years from 1992 to 2011 to evaluate probability of aircraft crash into reactor facilities. The method for developing the database of aircraft accidents to evaluate probability of aircraft crash into reactor facilities is based on the report 'The criteria on assessment of probability of aircraft crash into light water reactor facilities' described above. The 2012 revised database for the latest 20 years from 1992 to 2011 shows the followings. The trend of the 2012 database changes little as compared to the last year's report. (1) The data of commercial aircraft accidents is based on 'Aircraft accident investigation reports of Japan transport safety board' of Ministry of Land, Infrastructure, Transport and Tourism. The number of commercial aircraft accidents is 4 for large fixed-wing aircraft, 58 for small fixed-wing aircraft, 5 for large bladed aircraft and 99 for small bladed aircraft. The relevant accidents
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Noise Scaling and Community Noise Metrics for the Hybrid Wing Body Aircraft
Burley, Casey L.; Brooks, Thomas F.; Hutcheson, Florence V.; Doty, Michael J.; Lopes, Leonard V.; Nickol, Craig L.; Vicroy, Dan D.; Pope, D. Stuart
2014-01-01
An aircraft system noise assessment was performed for the hybrid wing body aircraft concept, known as the N2A-EXTE. This assessment is a result of an effort by NASA to explore a realistic HWB design that has the potential to substantially reduce noise and fuel burn. Under contract to NASA, Boeing designed the aircraft using practical aircraft design princip0les with incorporation of noise technologies projected to be available in the 2020 timeframe. NASA tested 5.8% scale-mode of the design in the NASA Langley 14- by 22-Foot Subsonic Tunnel to provide source noise directivity and installation effects for aircraft engine and airframe configurations. Analysis permitted direct scaling of the model-scale jet, airframe, and engine shielding effect measurements to full-scale. Use of these in combination with ANOPP predictions enabled computations of the cumulative (CUM) noise margins relative to FAA Stage 4 limits. The CUM margins were computed for a baseline N2A-EXTE configuration and for configurations with added noise reduction strategies. The strategies include reduced approach speed, over-the-rotor line and soft-vane fan technologies, vertical tail placement and orientation, and modified landing gear designs with fairings. Combining the inherent HWB engine shielding by the airframe with added noise technologies, the cumulative noise was assessed at 38.7 dB below FAA Stage 4 certification level, just 3.3 dB short of the NASA N+2 goal of 42 dB. This new result shows that the NASA N+2 goal is approachable and that significant reduction in overall aircraft noise is possible through configurations with noise reduction technologies and operational changes.
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Fuel cell climatic tests designed for new configured aircraft application
International Nuclear Information System (INIS)
Begot, Sylvie; Harel, Fabien; Candusso, Denis; Francois, Xavier; Pera, Marie-Cecile; Yde-Andersen, Steen
2010-01-01
The implementation of Fuel Cell (FC) systems in transportation systems, as aircrafts, requires some better understanding and mastering of the new generator behaviours in low temperature environments. To this end, a PEMFC stack is tested and characterised in a climatic chamber. The impacts of the low temperatures over different FC operation and start-up conditions are estimated using a specific test bench developed in-lab. Some descriptions concerning the test facilities and the experimental set-up are given in the paper, as well as some information about the test procedures applied. Some examples of test results are shown and analysed. The experiments are derived from aircraft requirements and are related with different scenarios of airplane operation. Finally, some assessments concerning the FC system behaviour in low temperature conditions are made, especially with regard to the constraints to be encountered by the next embedded FC generators.
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Fuel cell climatic tests designed for new configured aircraft application
Energy Technology Data Exchange (ETDEWEB)
Begot, Sylvie; Pera, Marie-Cecile [FC LAB, Rue Thierry Mieg, F 90010 Belfort Cedex (France); Franche-Comte Electronique Mecanique Thermique et Optique - Sciences et Technologies (FEMTO-ST), Departement energie et ingenierie des systemes multiphysiques (ENISYS), Unite Mixte de Recherche (UMR) du Centre National de la Recherche Scientifique (CNRS) 6174, University of Franche-Comte (UFC) (France); Harel, Fabien; Candusso, Denis [FC LAB, Rue Thierry Mieg, F 90010 Belfort Cedex (France); The French National Institute for Transport and Safety Research (INRETS), Transports and Environment Laboratory (LTE), Laboratory for New Technologies (LTN) (France); Francois, Xavier [FC LAB, Rue Thierry Mieg, F 90010 Belfort Cedex (France); FC LAB, University of Technology Belfort-Montbeliard (UTBM) (France); Yde-Andersen, Steen [IRD Fuel Cells A/S, Kullinggade 31, 5700 Svendborg (Denmark)
2010-07-15
The implementation of Fuel Cell (FC) systems in transportation systems, as aircrafts, requires some better understanding and mastering of the new generator behaviours in low temperature environments. To this end, a PEMFC stack is tested and characterised in a climatic chamber. The impacts of the low temperatures over different FC operation and start-up conditions are estimated using a specific test bench developed in-lab. Some descriptions concerning the test facilities and the experimental set-up are given in the paper, as well as some information about the test procedures applied. Some examples of test results are shown and analysed. The experiments are derived from aircraft requirements and are related with different scenarios of airplane operation. Finally, some assessments concerning the FC system behaviour in low temperature conditions are made, especially with regard to the constraints to be encountered by the next embedded FC generators. (author)
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Applications of a damage tolerance analysis methodology in aircraft design and production
Woodward, M. R.; Owens, S. D.; Law, G. E.; Mignery, L. A.
1992-01-01
Objectives of customer mandated aircraft structural integrity initiatives in design are to guide material selection, to incorporate fracture resistant concepts in the design, to utilize damage tolerance based allowables and planned inspection procedures necessary to enhance the safety and reliability of manned flight vehicles. However, validated fracture analysis tools for composite structures are needed to accomplish these objectives in a timely and economical manner. This paper briefly describes the development, validation, and application of a damage tolerance methodology for composite airframe structures. A closed-form analysis code, entitled SUBLAM was developed to predict the critical biaxial strain state necessary to cause sublaminate buckling-induced delamination extension in an impact damaged composite laminate. An embedded elliptical delamination separating a thin sublaminate from a thick parent laminate is modelled. Predicted failure strains were correlated against a variety of experimental data that included results from compression after impact coupon and element tests. An integrated analysis package was developed to predict damage tolerance based margin-of-safety (MS) using NASTRAN generated loads and element information. Damage tolerance aspects of new concepts are quickly and cost-effectively determined without the need for excessive testing.
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Aircraft Fuel Cell Power Systems
Needham, Robert
2004-01-01
In recent years, fuel cells have been explored for use in aircraft. While the weight and size of fuel cells allows only the smallest of aircraft to use fuel cells for their primary engines, fuel cells have showed promise for use as auxiliary power units (APUs), which power aircraft accessories and serve as an electrical backup in case of an engine failure. Fuel cell MUS are both more efficient and emit fewer pollutants. However, sea-level fuel cells need modifications to be properly used in aircraft applications. At high altitudes, the ambient air has a much lower pressure than at sea level, which makes it much more difficult to get air into the fuel cell to react and produce electricity. Compressors can be used to pressurize the air, but this leads to added weight, volume, and power usage, all of which are undesirable things. Another problem is that fuel cells require hydrogen to create electricity, and ever since the Hindenburg burst into flames, aircraft carrying large quantities of hydrogen have not been in high demand. However, jet fuel is a hydrocarbon, so it is possible to reform it into hydrogen. Since jet fuel is already used to power conventional APUs, it is very convenient to use this to generate the hydrogen for fuel-cell-based APUs. Fuel cells also tend to get large and heavy when used for applications that require a large amount of power. Reducing the size and weight becomes especially beneficial when it comes to fuel cells for aircraft. My goal this summer is to work on several aspects of Aircraft Fuel Cell Power System project. My first goal is to perform checks on a newly built injector rig designed to test different catalysts to determine the best setup for reforming Jet-A fuel into hydrogen. These checks include testing various thermocouples, transmitters, and transducers, as well making sure that the rig was actually built to the design specifications. These checks will help to ensure that the rig will operate properly and give correct results
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Skillen, Michael D.; Crossley, William A.
2008-01-01
This report presents an approach for sizing of a morphing aircraft based upon a multi-level design optimization approach. For this effort, a morphing wing is one whose planform can make significant shape changes in flight - increasing wing area by 50% or more from the lowest possible area, changing sweep 30 or more, and/or increasing aspect ratio by as much as 200% from the lowest possible value. The top-level optimization problem seeks to minimize the gross weight of the aircraft by determining a set of "baseline" variables - these are common aircraft sizing variables, along with a set of "morphing limit" variables - these describe the maximum shape change for a particular morphing strategy. The sub-level optimization problems represent each segment in the morphing aircraft's design mission; here, each sub-level optimizer minimizes fuel consumed during each mission segment by changing the wing planform within the bounds set by the baseline and morphing limit variables from the top-level problem.
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Toward a human-centered aircraft automation philosophy
Billings, Charles E.
1989-01-01
The evolution of automation in civil aircraft is examined in order to discern trends in the respective roles and functions of automation technology and the humans who operate these aircraft. The effects of advances in automation technology on crew reaction is considered and it appears that, though automation may well have decreased the frequency of certain types of human errors in flight, it may also have enabled new categories of human errors, some perhaps less obvious and therefore more serious than those it has alleviated. It is suggested that automation could be designed to keep the pilot closer to the control of the vehicle, while providing an array of information management and aiding functions designed to provide the pilot with data regarding flight replanning, degraded system operation, and the operational status and limits of the aircraft, its systems, and the physical and operational environment. The automation would serve as the pilot's assistant, providing and calculating data, watching for the unexpected, and keeping track of resources and their rate of expenditure.
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10 CFR 50.150 - Aircraft impact assessment.
2010-01-01
... maintained. (2) Aircraft impact characteristics.1 The assessment must be based on the beyond-design-basis... capabilities identified in paragraph (a)(1) of this section meet the assessment requirements in paragraph (a)(1... modified design features and functional capabilities continue to meet the assessment requirements in...
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Fuel-conservative guidance system for powered-lift aircraft
Erzberger, H.; Mclean, J. D.
1979-01-01
A concept for automatic terminal area guidance, comprising two modes of operation, was developed and evaluated in flight tests. In the predictive mode, fuel efficient approach trajectories are synthesized in fast time. In the tracking mode, the synthesized trajectories are reconstructed and tracked automatically. An energy rate performance model derived from the lift, drag, and propulsion system characteristics of the aircraft is used in the synthesis algorithm. The method optimizes the trajectory for the initial aircraft position and wind and temperature profiles encountered during each landing approach. The design theory and the results of simulations and flight tests using the Augmentor Wing Jet STOL Research Aircraft are described.
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Application of slender wing benefits to military aircraft
Polhamus, E. C.
1983-01-01
A review is provided of aerodynamic research conducted at the Langley Research Center with respect to the application of slender wing benefits in the design of high-speed military aircraft, taking into account the supersonic performance and leading-edge vortex flow associated with very highly sweptback wings. The beginning of the development of modern classical swept wing jet aircraft is related to the German Me 262 project during World War II. In the U.S., a theoretical study conducted by Jones (1945) pointed out the advantages of the sweptback wing concept. Developments with respect to variable sweep wings are discussed, taking into account early research in 1946, a joint program of the U.S. with the United Kingdom, the tactical aircraft concept, and the important part which the Langley variable-sweep research program played in the development of the F-111, F-14, and B-1. Attention is also given to hybrid wings, vortex flow theory development, and examples of flow design technology.
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Probabilistic Modeling of Aircraft Trajectories for Dynamic Separation Volumes
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.
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Design of sensors for in-flight lightning detection on aircrafts
Deursen, van A.P.J.; Stelmashuk, V.
2009-01-01
In the EU FP6 project ILDAS a prototype In-flight Lightning Damage Assessment System is developed for passenger aircraft and helicopter. The project aims to localize the attachment and the severity of the strokes during flight to assist maintenance. A database of events will be constructed to
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Scaling trajectories in civil aircraft (1913-1997)
Frenken, K.; Leydesdorff, L.
2000-01-01
Using entropy statistics we analyse scaling patterns in terms of changes in the ratios among product characteristics of 143 designs in civil aircraft. Two allegedly dominant designs, the piston propeller DC3 and the turbofan Boeing 707, are shown to have triggered a scaling trajectory at the level
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Inlet Trade Study for a Low-Boom Aircraft Demonstrator
Heath, Christopher M.; Slater, John W.; Rallabhandi, Sriram K.
2016-01-01
Propulsion integration for low-boom supersonic aircraft requires careful inlet selection, placement, and tailoring to achieve acceptable propulsive and aerodynamic performance, without compromising vehicle sonic boom loudness levels. In this investigation, an inward-turning streamline-traced and axisymmetric spike inlet are designed and independently installed on a conceptual low-boom supersonic demonstrator aircraft. The airframe was pre-shaped to achieve a target ground under-track loudness of 76.4 PLdB at cruise using an adjoint-based design optimization process. Aircraft and inlet performance characteristics were obtained by solution of the steady-state Reynolds-averaged Navier-Stokes equations. Isolated cruise inlet performance including total pressure recovery and distortion were computed and compared against installed inlet performance metrics. Evaluation of vehicle near-field pressure signatures, along with under- and off-track propagated loudness levels is also reported. Results indicate the integrated axisymmetric spike design offers higher inlet pressure recovery, lower fan distortion, and reduced sonic boom. The vehicle with streamline-traced inlet exhibits lower external wave drag, which translates to a higher lift-to-drag ratio and increased range capability.
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Comparison of Requirements for Composite Structures for Aircraft and Space Applications
Raju, Ivatury S.; Elliot, Kenny B.; Hampton, Roy W.; Knight, Norman F., Jr.; Aggarwal, Pravin; Engelstad, Stephen P.; Chang, James B.
2010-01-01
In this report, the aircraft and space vehicle requirements for composite structures are compared. It is a valuable exercise to study composite structural design approaches used in the airframe industry and to adopt methodology that is applicable for space vehicles. The missions, environments, analysis methods, analysis validation approaches, testing programs, build quantities, inspection, and maintenance procedures used by the airframe industry, in general, are not transferable to spaceflight hardware. Therefore, while the application of composite design approaches from aircraft and other industries is appealing, many aspects cannot be directly utilized. Nevertheless, experiences and research for composite aircraft structures may be of use in unexpected arenas as space exploration technology develops, and so continued technology exchanges are encouraged.
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ABOUT THE FORMATION OF THE DEVELOPMENT COSTS OF THE AIRCRAFT
I. V. Artemenko; V. S. Oleshko; V. M. Samoylenko
2015-01-01
The article discusses approaches to the formation of the limit prices of aircraft with using of elements of economic-mathematical modeling. Theoretical and practical aspects of development of methods of solving economic problems in the implementation of the mechanism of formation of effective innovation-stimulating prices in the drafting and design of aircraft.
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Study of aircraft electrical power systems
1972-01-01
The formulation of a philosophy for devising a reliable, efficient, lightweight, and cost effective electrical power system for advanced, large transport aircraft in the 1980 to 1985 time period is discussed. The determination and recommendation for improvements in subsystems and components are also considered. All aspects of the aircraft electrical power system including generation, conversion, distribution, and utilization equipment were considered. Significant research and technology problem areas associated with the development of future power systems are identified. The design categories involved are: (1) safety-reliability, (2) power type, voltage, frequency, quality, and efficiency, (3) power control, and (4) selection of utilization equipment.
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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.
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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....
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Aircraft and background noise annoyance effects
Willshire, K. F.
1984-01-01
To investigate annoyance of multiple noise sources, two experiments were conducted. The first experiment, which used 48 subjects, was designed to establish annoyance-noise level functions for three community noise sources presented individually: jet aircraft flyovers, air conditioner, and traffic. The second experiment, which used 216 subjects, investigated the effects of background noise on aircraft annoyance as a function of noise level and spectrum shape; and the differences between overall, aircraft, and background noise annoyance. In both experiments, rated annoyance was the dependent measure. Results indicate that the slope of the linear relationship between annoyance and noise level for traffic is significantly different from that of flyover and air conditioner noise and that further research was justified to determine the influence of the two background noises on overall, aircraft, and background noise annoyance (e.g., experiment two). In experiment two, total noise exposure, signal-to-noise ratio, and background source type were found to have effects on all three types of annoyance. Thus, both signal-to-noise ratio, and the background source must be considered when trying to determine community response to combined noise sources.
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Preliminary Design of the Low Speed Propulsion Air Intake of the LAPCAT-MR2 Aircraft
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
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Aircraft operability methods applied to space launch vehicles
Young, Douglas
1997-01-01
The commercial space launch market requirement for low vehicle operations costs necessitates the application of methods and technologies developed and proven for complex aircraft systems. The ``building in'' of reliability and maintainability, which is applied extensively in the aircraft industry, has yet to be applied to the maximum extent possible on launch vehicles. Use of vehicle system and structural health monitoring, automated ground systems and diagnostic design methods derived from aircraft applications support the goal of achieving low cost launch vehicle operations. Transforming these operability techniques to space applications where diagnostic effectiveness has significantly different metrics is critical to the success of future launch systems. These concepts will be discussed with reference to broad launch vehicle applicability. Lessons learned and techniques used in the adaptation of these methods will be outlined drawing from recent aircraft programs and implementation on phase 1 of the X-33/RLV technology development program.
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Guynn, Mark D.; Freh, Joshua E.; Olson, Erik D.
2004-01-01
This report describes the analytical modeling and evaluation of an unconventional commercial transport aircraft concept designed to address aircraft noise and emission issues. A blended-wing-body configuration with advanced technology hydrogen fuel cell electric propulsion is considered. Predicted noise and emission characteristics are compared to a current technology conventional configuration designed for the same mission. The significant technology issues which have to be addressed to make this concept a viable alternative to current aircraft designs are discussed. This concept is one of the "Quiet Green Transport" aircraft concepts studied as part of NASA's Revolutionary Aerospace Systems Concepts (RASC) Program. The RASC Program was initiated to develop revolutionary concepts that address strategic objectives of the NASA Enterprises, such as reducing aircraft noise and emissions, and to identify advanced technology requirements for the concepts.
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Development and validation of bonded composite doubler repairs for commercial aircraft.
Energy Technology Data Exchange (ETDEWEB)
Roach, Dennis Patrick; Rackow, Kirk A.
2007-07-01
A typical aircraft can experience over 2,000 fatigue cycles (cabin pressurizations) and even greater flight hours in a single year. An unavoidable by-product of aircraft use is that crack, impact, and corrosion flaws develop throughout the aircraft's skin and substructure elements. Economic barriers to the purchase of new aircraft have placed even greater demands on efficient and safe repair methods. The use of bonded composite doublers offers the airframe manufacturers and aircraft maintenance facilities a cost effective method to safely extend the lives of their aircraft. Instead of riveting multiple steel or aluminum plates to facilitate an aircraft repair, it is now possible to bond a single Boron-Epoxy composite doubler to the damaged structure. The FAA's Airworthiness Assurance Center at Sandia National Labs (AANC), Boeing, and Federal Express completed a pilot program to validate and introduce composite doubler repair technology to the U.S. commercial aircraft industry. This project focused on repair of DC-10 fuselage structure and its primary goal was to demonstrate routine use of this repair technology using niche applications that streamline the design-to-installation process. As composite doubler repairs gradually appear in the commercial aircraft arena, successful flight operation data is being accumulated. These commercial aircraft repairs are not only demonstrating the engineering and economic advantages of composite doubler technology but they are also establishing the ability of commercial maintenance depots to safely adopt this repair technique. This report presents the array of engineering activities that were completed in order to make this technology available for widespread commercial aircraft use. Focused laboratory testing was conducted to compliment the field data and to address specific issues regarding damage tolerance and flaw growth in composite doubler repairs. Fatigue and strength tests were performed on a simulated wing
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Modeling and Simulation of Power Distribution System in More Electric Aircraft
Directory of Open Access Journals (Sweden)
Zhangang Yang
2015-01-01
Full Text Available The More Electric Aircraft concept is a fast-developing trend in modern aircraft industry. With this new concept, the performance of the aircraft can be further optimized and meanwhile the operating and maintenance cost will be decreased effectively. In order to optimize the power system integrity and have the ability to investigate the performance of the overall system in any possible situations, one accurate simulation model of the aircraft power system will be very helpful and necessary. This paper mainly introduces a method to build a simulation model for the power distribution system, which is based on detailed component models. The power distribution system model consists of power generation unit, transformer rectifier unit, DC-DC converter unit, and DC-AC inverter unit. In order to optimize the performance of the power distribution system and improve the quality of the distributed power, a feedback control network is designed based on the characteristics of the power distribution system. The simulation result indicates that this new simulation model is well designed and it works accurately. Moreover, steady state performance and transient state performance of the model can fulfill the requirements of aircraft power distribution system in the realistic application.
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Defining the Ecological Coefficient of Performance for an Aircraft Propulsion System
Şöhret, Yasin
2018-05-01
The aircraft industry, along with other industries, is considered responsible these days regarding environmental issues. Therefore, the performance evaluation of aircraft propulsion systems should be conducted with respect to environmental and ecological considerations. The current paper aims to present the ecological coefficient of performance calculation methodology for aircraft propulsion systems. The ecological coefficient performance is a widely-preferred performance indicator of numerous energy conversion systems. On the basis of thermodynamic laws, the methodology used to determine the ecological coefficient of performance for an aircraft propulsion system is parametrically explained and illustrated in this paper for the first time. For a better understanding, to begin with, the exergy analysis of a turbojet engine is described in detail. Following this, the outputs of the analysis are employed to define the ecological coefficient of performance for a turbojet engine. At the end of the study, the ecological coefficient of performance is evaluated parametrically and discussed depending on selected engine design parameters and performance measures. The author asserts the ecological coefficient of performance to be a beneficial indicator for researchers interested in aircraft propulsion system design and related topics.
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Total aircraft flight-control system - Balanced open- and closed-loop control with dynamic trim maps
Smith, G. A.; Meyer, G.
1979-01-01
The availability of the airborne digital computer has made possible a Total Aircraft Flight Control System (TAFCOS) that uses virtually the complete nonlinear propulsive and aerodynamic data for the aircraft to construct dynamic trim maps that represent an inversion of the aircraft model. The trim maps, in series with the aircraft, provide essentially a linear feed-forward path. Basically, open-loop trajectory control is employed with only a small perturbation feedback signal required to compensate for inaccuracy in the aircraft model and for external disturbances. Simulation results for application to an automatic carrier-landing system are presented. Flight-test results for a STOL aircraft operating automatically over a major portion of its flight regime are presented. The concept promises a more rapid and straightforward design from aerodynamic principles, particularly for highly nonlinear configurations, and requires substantially less digital computer capacity than conventional automatic flight-control system designs.
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A New Cryocooler for MgB2 Superconducting Systems in Turboelectric Aircraft, Phase II
National Aeronautics and Space Administration — Turboelectric aircraft with gas turbines driving electric generators connected to electric propulsion motors have the potential to transform the aircraft design...
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A New Cryocooler for MgB2 Superconducting Systems in Turboelectric Aircraft, Phase I
National Aeronautics and Space Administration — Turboelectric aircraft with gas turbines driving electric generators connected to electric propulsion motors have the potential to transform the aircraft design...
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Small Aircraft Transportation System, Higher Volume Operations Concept: Normal Operations
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.
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Radar Detectability of Light Aircraft
1976-04-01
a vestigial blind speed at 121 knots. Aircraft radial velocity compon- ents for the flights discussed here varied between zero and 125 knots. Typi.cal...the contributions of Mr. D.M. Selwyn who designed the digital recording equipment and organized the flight tests, and Dr. A.W.R. Gilchrist who edited
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ABOUT THE FORMATION OF THE DEVELOPMENT COSTS OF THE AIRCRAFT
Directory of Open Access Journals (Sweden)
I. V. Artemenko
2015-01-01
Full Text Available The article discusses approaches to the formation of the limit prices of aircraft with using of elements of economic-mathematical modeling. Theoretical and practical aspects of development of methods of solving economic problems in the implementation of the mechanism of formation of effective innovation-stimulating prices in the drafting and design of aircraft.
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Superconducting and conventional electromagnetic launch system for civil aircraft assisted take-off
Bertola, Luca; Cox, Thomas; Wheeler, Patrick; Garvey, Seamus D.
2016-01-01
This paper compares three possible linear motor topologies for an electromagnetic launch system to assist civil aircraft take-off. Assisted launch of civil aircraft has the potential of reducing the required runway length, reducing noise and emissions near airports and improving overall aircraft efficiency through reducing engine thrust requirements. A comparison is made of practical designs of a linear induction motor, a linear permanent magnet synchronous motor and a superconducting linear ...
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Practical application of AMLCDs for tactical fighter aircraft
McClaskey, Paul; Craddock, Roger
1995-06-01
Development and testing of an AMLCD-display to replace a dichroic display in a fighter aircraft environment has presented a unique set of technical challenges. This paper addresses design concepts used on the Engine Fuel Display and proposes design guidelines generally applicable for AMLCD projects.
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Lightning protection technology for small general aviation composite material aircraft
Plumer, J. A.; Setzer, T. E.; Siddiqi, S.
1993-01-01
An on going NASA (Small Business Innovative Research) SBIR Phase II design and development program will produce the first lightning protected, fiberglass, General Aviation aircraft that is available as a kit. The results obtained so far in development testing of typical components of the aircraft kit, such as the wing and fuselage panels indicate that the lightning protection design methodology and materials chosen are capable of protecting such small composite airframes from lightning puncture and structural damage associated with severe threat lightning strikes. The primary objective of the program has been to develop a lightening protection design for full scale test airframe and verify its adequacy with full scale laboratory testing, thus enabling production and sale of owner-built, lightning-protected, Stoddard-Hamilton Aircraft, Inc. Glasair II airplanes. A second objective has been to provide lightning protection design guidelines for the General Aviation industry, and to enable these airplanes to meet lightening protection requirements for certification of small airplanes. This paper describes the protection design approaches and development testing results obtained thus far in the program, together with design methodology which can achieve the design goals listed above. The presentation of this paper will also include results of some of the full scale verification tests, which will have been completed by the time of this conference.
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Congestion Pricing for Aircraft Pushback Slot Allocation
Zhang, Yaping
2017-01-01
In order to optimize aircraft pushback management during rush hour, aircraft pushback slot allocation based on congestion pricing is explored while considering monetary compensation based on the quality of the surface operations. First, the concept of the “external cost of surface congestion” is proposed, and a quantitative study on the external cost is performed. Then, an aircraft pushback slot allocation model for minimizing the total surface cost is established. An improved discrete differential evolution algorithm is also designed. Finally, a simulation is performed on Xinzheng International Airport using the proposed model. By comparing the pushback slot control strategy based on congestion pricing with other strategies, the advantages of the proposed model and algorithm are highlighted. In addition to reducing delays and optimizing the delay distribution, the model and algorithm are better suited for use for actual aircraft pushback management during rush hour. Further, it is also observed they do not result in significant increases in the surface cost. These results confirm the effectiveness and suitability of the proposed model and algorithm. PMID:28114429
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Congestion Pricing for Aircraft Pushback Slot Allocation.
Liu, Lihua; Zhang, Yaping; Liu, Lan; Xing, Zhiwei
2017-01-01
In order to optimize aircraft pushback management during rush hour, aircraft pushback slot allocation based on congestion pricing is explored while considering monetary compensation based on the quality of the surface operations. First, the concept of the "external cost of surface congestion" is proposed, and a quantitative study on the external cost is performed. Then, an aircraft pushback slot allocation model for minimizing the total surface cost is established. An improved discrete differential evolution algorithm is also designed. Finally, a simulation is performed on Xinzheng International Airport using the proposed model. By comparing the pushback slot control strategy based on congestion pricing with other strategies, the advantages of the proposed model and algorithm are highlighted. In addition to reducing delays and optimizing the delay distribution, the model and algorithm are better suited for use for actual aircraft pushback management during rush hour. Further, it is also observed they do not result in significant increases in the surface cost. These results confirm the effectiveness and suitability of the proposed model and algorithm.
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Congestion Pricing for Aircraft Pushback Slot Allocation.
Directory of Open Access Journals (Sweden)
Lihua Liu
Full Text Available In order to optimize aircraft pushback management during rush hour, aircraft pushback slot allocation based on congestion pricing is explored while considering monetary compensation based on the quality of the surface operations. First, the concept of the "external cost of surface congestion" is proposed, and a quantitative study on the external cost is performed. Then, an aircraft pushback slot allocation model for minimizing the total surface cost is established. An improved discrete differential evolution algorithm is also designed. Finally, a simulation is performed on Xinzheng International Airport using the proposed model. By comparing the pushback slot control strategy based on congestion pricing with other strategies, the advantages of the proposed model and algorithm are highlighted. In addition to reducing delays and optimizing the delay distribution, the model and algorithm are better suited for use for actual aircraft pushback management during rush hour. Further, it is also observed they do not result in significant increases in the surface cost. These results confirm the effectiveness and suitability of the proposed model and algorithm.
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Demonstrative Maneuvers for Aircraft Agility Predictions
2008-03-01
AIAA Paper 1996-3741. 19. Raymer , Daniel P. Aircraft Design: A Conceptual Approach. American Institute of Aeronautics and Astronautics, Inc., 3rd...Shaw, Robert L. Fighter Combat: Tactics and Maneuvering. Naval Institute Press, Annapolis, MD, 1985. 25. Smith, Steven W. The Scientist and
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Phenomena of Foamed Concrete under Rolling of Aircraft Wheels
Jiang, Chun-shui; Yao, Hong-yu; Xiao, Xian-bo; Kong, Xiang-jun; Shi, Ya-jie
2014-04-01
Engineered Material Arresting System (EMAS) is an effective technique to reduce hazards associated with aircraft overrunning runway. In order to ascertain phenomena of the foamed concrete used for EMAS under rolling of aircraft wheel, a specially designed experimental setup was built which employed Boeing 737 aircraft wheels bearing actual vertical loads to roll through the foamed concrete. A number of experiments were conducted upon this setup. It is discovered that the wheel rolls the concrete in a pure rolling manner and crushes the concrete downwards, instead of crushing it forward, as long as the concrete is not higher than the wheel axle. The concrete is compressed into powder in-situ by the wheel and then is brought to bottom of the wheel. The powder under the wheel is loose and thus is not able to sustain wheel braking. It is also found that after being rolled by the wheel the concrete exhibits either of two states, i.e. either 'crushed through' whole thickness of the concrete or 'crushed halfway', depending on combination of strength of the concrete, thickness of the concrete, vertical load the wheel carries, tire dimension and tire pressure. A new EMAS design concept is developed that if an EMAS design results in the 'crushed through' state for the main gears while the 'crushed halfway' state for the nose gear, the arresting bed would be optimal to accommodate the large difference in strength between the nose gear and the main gear of an aircraft.
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Roles, uses, and benefits of general aviation aircraft in aerospace engineering education
Odonoghue, Dennis P.; Mcknight, Robert C.
1994-01-01
Many colleges and universities throughout the United States offer outstanding programs in aerospace engineering. In addition to the fundamentals of aerodynamics, propulsion, flight dynamics, and air vehicle design, many of the best programs have in the past provided students the opportunity to design and fly airborne experiments on board various types of aircraft. Sadly, however, the number of institutions offering such 'airborne laboratories' has dwindled in recent years. As a result, opportunities for students to apply their classroom knowledge, analytical skills, and engineering judgement to the development and management of flight experiments on an actual aircraft are indeed rare. One major reason for the elimination of flight programs by some institutions, particularly the smaller colleges, is the prohibitive cost of operating and maintaining an aircraft as a flying laboratory. The purpose of this paper is to discuss simple, low-cost, relevant flight experiments that can be performed using readily available general aviation aircraft. This paper examines flight experiments that have been successfully conducted on board the NASA Lewis Research Center's T-34B aircraft, as part of the NASA/AIAA/University Flight Experiment Program for Students (NAUFEPS) and discusses how similar experiments could be inexpensively performed on other general aviation aircraft.
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Integral Transportation Systems in Military Transport Aircraft Supply
Directory of Open Access Journals (Sweden)
Dražen Kovačević
2012-10-01
Full Text Available Supply of goods, equipment and soldiers by militwy transportaircraft can serve as a support to airborne landing operation,support to encircled forces, and support to forces leadinga gue1rilla war. Transport aircraft are designed in such a wayas to be able to cany containers, pallets, most of land vehiclesand helicopters. Militwy transport aircraft can be grouped intothose that were originally designed for military transp01t andthose that are modified civilian aircraft and helicopters. Supplypallets can be wooden, metal, can be airdropped in "taxiing","low-flight", and can also be fitted with a parachute or"retrorocket" for reducing the ground impact. Pallets canamong other things carry liquids, heavy combat and ca1rier vehicles,artillery and rocket weapons and valious containers.Pallets are usually pe1manently deformed at ground impact.Nowadays, high precision of airdrop has been achieved. Containersare used to carry various equipment, food, fue~ weapons,ammunition etc. It is to be expected that the containers,wmoured combat and other vehicles will be redesigned so asto provide more efficient transport and fast a!Tangement ofhigh-mobility units, whereas the form of the future militarytransport aircraft will not undergo substantial changes. By adjustingand standardising the transporlation vehicles, integraltransportation means and cwgo, the overall combat efficiencywill be increased, the a~rangement time especially shortenedand the air supply safety increased.
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Estimation of aircraft aerodynamic derivatives using Extended Kalman Filter
Curvo, M.
2000-01-01
Design of flight control laws, verification of performance predictions, and the implementation of flight simulations are tasks that require a mathematical model of the aircraft dynamics. The dynamical models are characterized by coefficients (aerodynamic derivatives) whose values must be determined from flight tests. This work outlines the use of the Extended Kalman Filter (EKF) in obtaining the aerodynamic derivatives of an aircraft. The EKF shows several advantages over the more traditional...
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Development of Stitched Composite Structure for Advanced Aircraft
Jegley, Dawn; Przekop, Adam; Rouse, Marshall; Lovejoy, Andrew; Velicki, Alex; Linton, Kim; Wu, Hsi-Yung; Baraja, Jaime; Thrash, Patrick; Hoffman, Krishna
2015-01-01
NASA has created the Environmentally Responsible Aviation Project to develop technologies which will reduce the impact of aviation on the environment. A critical aspect of this pursuit is the development of a lighter, more robust airframe that will enable the introduction of unconventional aircraft configurations. NASA and The Boeing Company are working together to develop a structural concept that is lightweight and an advancement beyond state-of-the-art composites. The Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) is an integrally stiffened panel design where elements are stitched together and designed to maintain residual load-carrying capabilities under a variety of damage scenarios. With the PRSEUS concept, through-the-thickness stitches are applied through dry fabric prior to resin infusion, and replace fasteners throughout each integral panel. Through-the-thickness reinforcement at discontinuities, such as along flange edges, has been shown to suppress delamination and turn cracks, which expands the design space and leads to lighter designs. The pultruded rod provides stiffening away from the more vulnerable skin surface and improves bending stiffness. A series of building blocks were evaluated to explore the fundamental assumptions related to the capability and advantages of PRSEUS panels. These building blocks addressed tension, compression, and pressure loading conditions. The emphasis of the development work has been to assess the loading capability, damage arrestment features, repairability, post-buckling behavior, and response of PRSEUS flat panels to out-of plane pressure loading. The results of this building-block program from coupons through an 80%-scale pressure box have demonstrated the viability of a PRSEUS center body for the Hybrid Wing Body (HWB) transport aircraft. This development program shows that the PRSEUS benefits are also applicable to traditional tube-andwing aircraft, those of advanced configurations, and other
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Mathematical Modeling of the Braking System of Wheeled Mainline Aircraft
Directory of Open Access Journals (Sweden)
I. S. Shumilov
2016-01-01
Full Text Available The braking system of the landing gear wheels of a mainline aircraft has to meet mandatory requirements laid out in the Aviation Regulations AP-25 (Para 25.735. «Brakes and brake systems". These requirements are essential when creating the landing gear wheel brake control system (WBCS and are used as main initial data in its mathematical modeling. The WBCS is one of the most important systems to ensure the safe completion of the flight. It is a complex of devices, i.e. units (hydraulic, electrical, and mechanical, connected through piping, wiring, mechanical constraints. This complex should allow optimizing the braking process when a large number of parameters change. The most important of them are the following: runway friction coefficient (RFC, lifting force, weight and of the aircraft, etc. The main structural elements involved in braking the aircraft are: aircraft wheels with pneumatics (air tires and brake discs, WBCS, and cooling system of gear wheels when braking.To consider the aircraft deceleration on the landing run is of essence at the stage of design, development, and improvement of brakes and braking systems. Based on analysis of equation of the aircraft motion and energy balance can be determined energy loading and its basic design parameters, braking distances and braking time.As practice and analysis of energy loading show, they (brake + wheel absorb the aircraftpossessed kinetic energy at the start of braking as much as 60-70%, 70-80%, and 80-90%, respectively, under normal increased, and emergency operating conditions. The paper presents a procedure for the rapid calculation of energy loading of the brake wheel.Currently, the mainline aircrafts use mainly electrohydraulic brake systems in which there are the main, backup, and emergency-parking brake systems. All channels are equipped with automatic anti-skid systems. Their presence in the emergency (the third reserve channel significantly improves the reliability and safety of
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Improved design of a high lift system for general aviation aircraft
Florjancic, D.; Steenhuizen, D.; Veldhuis, L.L.M.
2016-01-01
Optimization of a single slotted flap with dropped hinge is performed with the objective of increasing the payload of a propeller driven 4-seater general aviation aircraft. Within the optimization loop, two-dimensional aerodynamic characteristics are evaluated using the MSES code, while
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Propulsion controlled aircraft computer
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.
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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.
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Karpenko, S. S.; Zybin, E. Yu; Kosyanchuk, V. V.
2018-02-01
In this paper we design a nonparametric method for failures detection and localization in the aircraft control system that uses the measurements of the control signals and the aircraft states only. It doesn’t require a priori information of the aircraft model parameters, training or statistical calculations, and is based on algebraic solvability conditions for the aircraft model identification problem. This makes it possible to significantly increase the efficiency of detection and localization problem solution by completely eliminating errors, associated with aircraft model uncertainties.
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Frequency Analysis of Aircraft hazards for License Application
International Nuclear Information System (INIS)
K. Ashley
2006-01-01
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
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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.
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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...
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Structural analysis of aircraft impact on a nuclear powered ship
International Nuclear Information System (INIS)
Dietrich, R.
1976-01-01
As part of a general safety analysis, the reliability against structural damage due to an aircraft crash on a nuclear powered ship is evaluated. This structural analysis is an aid in safety design. It is assumed that a Phantom military jet-fighter hits a nuclear powered ship. The total reaction force due to such an aircraft impact on a rigid barrier is specified in the guidelines of the Reaktor-Sicherheitskommission (German Safety Advisory Committee) for pressurized water reactors. This paper investigates the aircraft impact on the collision barrier at the side of the ship. The aircraft impact on top of the reactor hatchway is investigated by another analysis. It appears that the most unfavorable angle of impact is always normal to the surface of the collision barrier. Consequently, only normal impact will be considered here. For the specific case of an aircraft striking a nuclear powered ship, the following two effects are considered: Local penetration and dynamic response of the structure. (Auth.)
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Mital, Subodh K.; Gyekenyesi, John Z.; Arnold, Steven M.; Sullivan, Roy M.; Manderscheid, Jane M.; Murthy, Pappu L. N.
2006-01-01
Due to its high specific energy content, liquid hydrogen (LH2) is emerging as an alternative fuel for future aircraft. As a result, there is a need for hydrogen tank storage systems, for these aircraft applications, that are expected to provide sufficient capacity for flight durations ranging from a few minutes to several days. It is understood that the development of a large, lightweight, reusable cryogenic liquid storage tank is crucial to meet the goals of and supply power to hydrogen-fueled aircraft, especially for long flight durations. This report provides an annotated review (including the results of an extensive literature review) of the current state of the art of cryogenic tank materials, structural designs, and insulation systems along with the identification of key challenges with the intent of developing a lightweight and long-term storage system for LH2. The broad classes of insulation systems reviewed include foams (including advanced aerogels) and multilayer insulation (MLI) systems with vacuum. The MLI systems show promise for long-term applications. Structural configurations evaluated include single- and double-wall constructions, including sandwich construction. Potential wall material candidates are monolithic metals as well as polymer matrix composites and discontinuously reinforced metal matrix composites. For short-duration flight applications, simple tank designs may suffice. Alternatively, for longer duration flight applications, a double-wall construction with a vacuum-based insulation system appears to be the most optimum design. The current trends in liner material development are reviewed in the case that a liner is required to minimize or eliminate the loss of hydrogen fuel through permeation.
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Energy and Economic Trade Offs for Advanced Technology Subsonic Aircraft
Maddalon, D. V.; Wagner, R. D.
1976-01-01
Changes in future aircraft technology which conserve energy are studied, along with the effect of these changes on economic performance. Among the new technologies considered are laminar-flow control, composite materials with and without laminar-flow control, and advanced airfoils. Aircraft design features studied include high-aspect-ratio wings, thickness ratio, and range. Engine technology is held constant at the JT9D level. It is concluded that wing aspect ratios of future aircraft are likely to significantly increase as a result of new technology and the push of higher fuel prices. Composite materials may raise aspect radio to about 11 to 12 and practical laminar flow-control systems may further increase aspect ratio to 14 or more. Advanced technology provides significant reductions in aircraft take-off gross weight, energy consumption, and direct operating cost.
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Advances in the analysis of NPP and other critical structures subjected to aircraft impact
International Nuclear Information System (INIS)
Riera, Jorge
2013-01-01
A brief overview of analysis and design criteria of structures subjected to aircraft impact was presented, focusing attention on factors considered of relevance for NPP design. One of these factors is related to model uncertainty, i.e. to the degree of belief of the designer in the numerical or analytical model employed to determine the structural response. Note that uncertainty grows as we approach the limits of past experience, region in which the analyst and design engineer find themselves when assessing the effects of aircraft impact
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NASA-Langley Research Center's Aircraft Condition Analysis and Management System Implementation
Frye, Mark W.; Bailey, Roger M.; Jessup, Artie D.
2004-01-01
This document describes the hardware implementation design and architecture of Aeronautical Radio Incorporated (ARINC)'s Aircraft Condition Analysis and Management System (ACAMS), which was developed at NASA-Langley Research Center (LaRC) for use in its Airborne Research Integrated Experiments System (ARIES) Laboratory. This activity is part of NASA's Aviation Safety Program (AvSP), the Single Aircraft Accident Prevention (SAAP) project to develop safety-enabling technologies for aircraft and airborne systems. The fundamental intent of these technologies is to allow timely intervention or remediation to improve unsafe conditions before they become life threatening.
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Aircraft crash upon a containment structure of a nuclear power plant
International Nuclear Information System (INIS)
Paul, D.K.; Abbas, H.; Godbole, P.N.; Nayak, G.C.
1993-01-01
The reinforced concrete outer containment of a Nuclear Power Plant (NPP) is required to be designed to withstand the impact of aircraft and aircrash debris etc. The problem is of strategic significance because the damage caused to the structure by these missiles may lead to the leakage of nuclear radiations. The safety design of NPP against aircraft crash requires the evaluation of crash probability. If the probability is smaller than the allowable value then the aircraft crash is neglected as design basis item. Otherwise adequate measures are taken to bring the released radioactive material within the permissible limit. The aircrafts and their striking velocity to be considered in the design of a structure are decided by the accident analysis. The probabilistic aspect of the problem has not been covered in the present work. The non-affordability of coupled analysis of large problems like aircraft crash on NPP, automobile impact on a structure etc. due to the requirement of excessive amount of manual as well as computer time and storage compels us to switch over to the uncoupled analysis. Moreover, the results of coupled analysis are heavily influenced by the analyst's modelling technique and choice of increment size. It is uncoupling of the missile and the target which converts the impact load to the impulse load. This impulse can be found by taking into consideration only the inertial and stiffness properties of missile and considering the target to be rigid. Though the impulse load so obtained disregards the inertial and stiffness characteristics of the target but its effect can be incorporated by modifying it for the inertial and stiffness properties of target at different time steps as we march in time domain during the analysis of the target
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1980-01-01
Project planning data for a rotor and control system procurement and testing program for modifications to the XV-15 tilt-rotor research demonstrator aircraft is presented. The design, fabrication, and installation of advanced composite blades compatible with the existing hub, an advanced composite hub, and a nonmechanical control system are required.
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NASA's Zero-g aircraft operations
Williams, R. K.
1988-01-01
NASA's Zero-g aircraft, operated by the Johnson Space Center, provides the unique weightless or zero-g environment of space flight for hardware development and test and astronaut training purposes. The program, which began in 1959, uses a slightly modified Boeing KC-135A aircraft, flying a parabolic trajectory, to produce weightless periods of 20 to 25 seconds. The program has supported the Mercury, Gemini, Apollo, Skylab, Apollo-Soyuz and Shuttle programs as well as a number of unmanned space operations. Typical experiments for flight in the aircraft have included materials processing experiments, welding, fluid manipulation, cryogenics, propellant tankage, satellite deployment dynamics, planetary sciences research, crew training with weightless indoctrination, space suits, tethers, etc., and medical studies including vestibular research. The facility is available to microgravity research organizations on a cost-reimbursable basis, providing a large, hands-on test area for diagnostic and support equipment for the Principal Investigators and providing an iterative-type design approach to microgravity experiment development. The facility allows concepts to be proven and baseline experimentation to be accomplished relatively inexpensively prior to committing to the large expense of a space flight.
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Aircraft Flight Modeling During the Optimization of Gas Turbine Engine Working Process
Tkachenko, A. Yu; Kuz'michev, V. S.; Krupenich, I. N.
2018-01-01
The article describes a method for simulating the flight of the aircraft along a predetermined path, establishing a functional connection between the parameters of the working process of gas turbine engine and the efficiency criteria of the aircraft. This connection is necessary for solving the optimization tasks of the conceptual design stage of the engine according to the systems approach. Engine thrust level, in turn, influences the operation of aircraft, thus making accurate simulation of the aircraft behavior during flight necessary for obtaining the correct solution. The described mathematical model of aircraft flight provides the functional connection between the airframe characteristics, working process of gas turbine engines (propulsion system), ambient and flight conditions and flight profile features. This model provides accurate results of flight simulation and the resulting aircraft efficiency criteria, required for optimization of working process and control function of a gas turbine engine.
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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.
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Ambur, Damodar R.
1995-01-01
A structurally efficient hat-stiffened panel concept that utilizes a structural foam as stiffener core has been designed for aircraft primary structural applications. This stiffener concept utilizes a manufacturing process that can be adapted readily to grid-stiffened structural configurations which possess inherent damage tolerance characteristics due to their multiplicity of load paths. The foam-filled hat-stiffener concept in a prismatically stiffened panel configuration is more efficient than most other stiffened panel configurations in a load range that is typical for both fuselage and wing structures. The prismatically stiffened panel concept investigated here has been designed using AS4/3502 preimpregnated tape and Rohacell foam core and evaluated for its buckling and postbuckling behavior with and without low-speed impact damage. The results from single-stiffener and multi-stiffener specimens suggest that this structural concept responds to loading as anticipated and has good damage tolerance characteristics.
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Khaimovich, I. N.
2017-10-01
The articles provides the calculation algorithms for blank design and die forming fitting to produce the compressor blades for aircraft engines. The design system proposed in the article allows generating drafts of trimming and reducing dies automatically, leading to significant reduction of work preparation time. The detailed analysis of the blade structural elements features was carried out, the taken limitations and technological solutions allowed forming generalized algorithms of forming parting stamp face over the entire circuit of the engraving for different configurations of die forgings. The author worked out the algorithms and programs to calculate three dimensional point locations describing the configuration of die cavity. As a result the author obtained the generic mathematical model of final die block in the form of three-dimensional array of base points. This model is the base for creation of engineering documentation of technological equipment and means of its control.
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Aeroelastic tailoring of composite aircraft wings
Mihaila-Andres, Mihai; Larco, Ciprian; Rosu, Paul-Virgil; Rotaru, Constantin
2017-07-01
The need of a continuously increasing size and performance of aerospace structures has settled the composite materials as the preferred materials in aircraft structures. Apart from the clear capacity to reduce the structural weight and with it the manufacture cost and the fuel consumption while preserving proper airworthiness, the prospect of tailoring a structure using the unique directional stiffness properties of composite materials allows an aerospace engineer to optimize aircraft structures to achieve particular design objectives. This paper presents a brief review of what is known as the aeroelastic tailoring of airframes with the intent of understanding the evolution of this research topic and at the same time providing useful references for further studies.
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Arunachalam, S.; Baek, B. H.; Vennam, P. L.; Woody, M. C.; Omary, M.; Binkowski, F.; Fleming, G.
2012-12-01
Commercial aircraft emit substantial amounts of pollutants during their complete activity cycle that ranges from landing-and-takeoff (LTO) at airports to cruising in upper elevations of the atmosphere, and affect both air quality and climate. Since these emissions are not uniformly emitted over the earth, and have substantial temporal and spatial variability, it is vital to accurately evaluate and quantify the relative impacts of aviation emissions on ambient air quality. Regional-scale air quality modeling applications do not routinely include these aircraft emissions from all cycles. Federal Aviation Administration (FAA) has developed the Aviation Environmental Design Tool (AEDT), a software system that dynamically models aircraft performance in space and time to calculate fuel burn and emissions from gate-to-gate for all commercial aviation activity from all airports globally. To process in-flight aircraft emissions and to provide a realistic representation of these for treatment in grid-based air quality models, we have developed an interface processor called AEDTproc that accurately distributes full-flight chorded emissions in time and space to create gridded, hourly model-ready emissions input data. Unlike the traditional emissions modeling approach of treating aviation emissions as ground-level sources or processing emissions only from the LTO cycles in regional-scale air quality studies, AEDTproc distributes chorded inventories of aircraft emissions during LTO cycles and cruise activities into a time-variant 3-D gridded structure. We will present results of processed 2006 global emissions from AEDT over a continental U.S. modeling domain to support a national-scale air quality assessment of the incremental impacts of aircraft emissions on surface air quality. This includes about 13.6 million flights within the U.S. out of 31.2 million flights globally. We will focus on assessing spatio-temporal variability of these commercial aircraft emissions, and
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Trust Control of VTOL Aircraft Part Deux
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.
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Integrated Network of Optimizations for Aircraft Systems, Phase I
National Aeronautics and Space Administration — Aircraft design is a complex process requiring interactions and exchange of information among multiple disciplines such as aerodynamics, strength, fatigue, controls,...
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The Impact of Rising Temperatures on Aircraft Takeoff Performance
Coffel, E.; Horton, R. M.; Thompson, T. R.
2017-12-01
Steadily rising mean and extreme temperatures as a result of climate change will likely impact the air transportation system over the coming decades. As air temperatures rise at constant pressure, air density declines, resulting in less lift generation by an aircraft wing at a given airspeed and potentially imposing a weight restriction on departing aircraft. This study presents a general model to project future weight restrictions across a fleet of aircraft with different takeoff weights operating at a variety of airports. We construct performance models for five common commercial aircraft and 19 major airports around the world and use projections of daily temperatures from the CMIP5 model suite under the RCP 4.5 and RCP 8.5 emissions scenarios to calculate required hourly weight restriction. We find that on average, 10-30% of annual flights departing at the time of daily maximum temperature may require some weight restriction below their maximum takeoff weights, with mean restrictions ranging from 0.5 to 4% of total aircraft payload and fuel capacity by mid- to late century. Both mid-sized and large aircraft are affected, and airports with short runways and high tempera- tures, or those at high elevations, will see the largest impacts. Our results suggest that weight restriction may impose a non-trivial cost on airlines and impact aviation operations around the world and that adaptation may be required in aircraft design, airline schedules, and/or runway lengths.
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No Winglets: What a Drag...Argument for Adding Winglets to Large Air Force Aircraft
2008-01-01
prices have once again brought improving aircraft aerodynamic efficiencies to the forefront of the energy conservation debate. Displaying how winglets ... winglet . Winglets are small, nearly vertical aerodynamic surfaces mounted on aircraft wingtips. Engineers design them with the same careful attention to...total drag.6 Since winglets , designed as small airfoils, reduce the aerodynamic drag associated with vortices by minimizing the amount of energy used
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Active Structural Control for Aircraft Efficiency with the X-56A Aircraft
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.
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X-36 Tailless Fighter Agility Research Aircraft in flight
1997-01-01
The lack of a vertical tail on the X-36 technology demonstrator is evident as the remotely piloted aircraft flies a low-altitude research flight above Rogers Dry Lake at Edwards Air Force Base in the California desert on October 30, 1997. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three
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Multi-Fuel Rotary Engine for General Aviation Aircraft
Jones, C.; Ellis, D. R.; Meng, P. R.
1983-01-01
Design studies, conducted for NASA, of Advanced Multi-fuel General Aviation and Commuter Aircraft Rotary Stratified Charge Engines are summarized. Conceptual design studies of an advanced engine sized to provide 186/250 shaft KW/HP under cruise conditions at 7620/25,000 m/ft. altitude were performed. Relevant engine development background covering both prior and recent engine test results of the direct injected unthrottled rotary engine technology, including the capability to interchangeably operate on gasoline, diesel fuel, kerosene, or aviation jet fuel, are presented and related to growth predictions. Aircraft studies, using these resultant growth engines, define anticipated system effects of the performance and power density improvements for both single engine and twin engine airplanes. The calculated results indicate superior system performance and 30 to 35% fuel economy improvement for the Rotary-engine airplanes as compared to equivalent airframe concept designs with current baseline engines. The research and technology activities required to attain the projected engine performance levels are also discussed.
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Sliding Mode Fault Tolerant Control with Adaptive Diagnosis for Aircraft Engines
Xiao, Lingfei; Du, Yanbin; Hu, Jixiang; Jiang, Bin
2018-03-01
In this paper, a novel sliding mode fault tolerant control method is presented for aircraft engine systems with uncertainties and disturbances on the basis of adaptive diagnostic observer. By taking both sensors faults and actuators faults into account, the general model of aircraft engine control systems which is subjected to uncertainties and disturbances, is considered. Then, the corresponding augmented dynamic model is established in order to facilitate the fault diagnosis and fault tolerant controller design. Next, a suitable detection observer is designed to detect the faults effectively. Through creating an adaptive diagnostic observer and based on sliding mode strategy, the sliding mode fault tolerant controller is constructed. Robust stabilization is discussed and the closed-loop system can be stabilized robustly. It is also proven that the adaptive diagnostic observer output errors and the estimations of faults converge to a set exponentially, and the converge rate greater than some value which can be adjusted by choosing designable parameters properly. The simulation on a twin-shaft aircraft engine verifies the applicability of the proposed fault tolerant control method.
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Low-Cost Composite Materials and Structures for Aircraft Applications
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.
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Impact of aircraft systems within aircraft operation: A MEA trajectory optimisation study
Seresinhe, R.
2014-01-01
Air transport has been a key component of the socio-economic globalisation. The ever increasing demand for air travel and air transport is a testament to the success of the aircraft. But this growing demand presents many challenges. One of which is the environmental impact due to aviation. The scope of the environmental impact of aircraft can be discussed from many viewpoints. This research focuses on the environmental impact due to aircraft operation. Aircraft operation causes...
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Retooling CFD for hypersonic aircraft
Dwoyer, Douglas L.; Kutler, Paul; Povinelli, Louis A.
1987-01-01
The CFD facility requirements of hypersonic aircraft configuration design development are different from those thus far employed for reentry vehicle design, because (1) the airframe and the propulsion system must be fully integrated to achieve the desired performance; (2) the vehicle must be reusable, with minimum refurbishment requirements between flights; and (3) vehicle performance must be optimized for a wide range of Mach numbers. An evaluation is presently made of flow resolution within shock waves, transition and turbulence phenomenon tractability, chemical reaction modeling, and hypersonic boundary layer transition, with state-of-the-art CFD.
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Klöckner, Andreas; Leitner, Martin; Schlabe, Daniel; Looye, Gertjan
2013-01-01
Solar-powered high-altitude unmanned platforms are highly optimized and integrated aircraft. In order to account for the complex, multi-physical interactions between their systems, we propose using integrated simulation models throughout the aircraft’s life cycle. Especially small teams with limited ressources should benefit from this approach. In this paper, we describe our approach to an integrated model of the Electric High-Altitude Solar-Powered Aircraft ELHASPA. It includes aspects of th...
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Airworthiness Certification of Fe-Si3N4-graphite Brake Composites for Military Aircraft
Directory of Open Access Journals (Sweden)
T.R. Prabhu
2015-12-01
Full Text Available Metal matrix hybrid composites are usually preferred for high energy aircraft (1-10 MJ brake pads (HEABP applications. The report focuses mainly on the evaluation of the wear and braking performance of the composite for the military aircraft applications. In this paper, the design and processing of a typical HEABP composite have been discussed in detail. The airworthiness qualification tests for the HEABP and the brake units are outlined with details. Also, brake testing parameters calculations derived from the typical aircraft data are presented for both the laboratory and full scale dynamometer tests. A case study of Fe-Si3N4- graphite composite pads is presented to exemplify the steps involved in the design, development, and airworthiness certification of HEABPs for the 8 MJ energy military aircraft. From the microstructure and wear surface morphology analysis and the results of brake performance parameters, functional tests and aircraft trials, it is concluded that the Fe-Si3N4- graphite composite has a minimum life of 200 normal energy landings with excellent braking performances.
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Aircraft to aircraft intercomparison during SEMAPHORE
Lambert, Dominique; Durand, Pierre
1998-10-01
During the Structure des Echanges Mer-Atmosphère, Propriétés des Hétérogénéités Océaniques: Recherche Expérimentale (SEMAPHORE) experiment, performed in the Azores region in 1993, two French research aircraft were simultaneously used for in situ measurements in the atmospheric boundary layer. We present the results obtained from one intercomparison flight between the two aircraft. The mean parameters generally agree well, although the temperature has to be slightly shifted in order to be in agreement for the two aircraft. A detailed comparison of the turbulence parameters revealed no bias. The agreement is good for variances and is satisfactory for fluxes and skewness. A thorough study of the errors involved in flux computation revealed that the greatest accuracy is obtained for latent heat flux. Errors in sensible heat flux are considerably greater, and the worst results are obtained for momentum flux. The latter parameter, however, is more accurate than expected from previous parameterizations.
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SCIENTIFIC AND PRACTICAL ASPECTS OF THE BULLETINS DEVELOPMENT FOR CIVIL AIRCRAFT
Directory of Open Access Journals (Sweden)
Andrey N. Petrov
2017-01-01
Full Text Available The paper outlines science and methodological aspects of issuing bulletins for the civil aircraft and practical prob- lems accumulated in the national aviation industry within the mentioned area. Bulletins are used to inform operators about the purpose, data content and technologies outlining the design changes accomplishment if the aircraft considered at the moment of the design changes is already at the operational stage. Hence maintaining aircraft airworthiness is impossible without making certain modifications and repairs in the design, the bulletins issuing and implementation procedures have notable impact on safety and effectiveness of air transportation.Deficiencies considered are the results of practices used since 1980 and supported by the later interstate standard GOST 31270-2004 in the field of the bulletins development and implementation, which are not in line with contemporary conditions of international civil aviation activities. Negative consequences of transferring the Soviet way of working with aircraft bulletins intothe changed conditions of the state regulation of civil aviation activities in Russia are shown as well as those for substantial com-plication of the rules and procedures in comparison to the standards of Unified System of Design Documentation.Main theses of the ICAO standards and international practice are briefly analyzed, however they are not complete- ly presented in the national aviation regulations. The recommendations proposed are aimed to eliminate mentioned defi- ciencies through the standards amendment process and improvement of Russia's civil aviation regulatory base. Developed recommendations are mainly focused on the formulation of the new concept and certain content of the revised standard requirements to replace GOST 31270-2004.
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Directory of Open Access Journals (Sweden)
Yamina BOUGHARI
2017-06-01
Full Text Available In this paper the Cessna Citation X clearance criteria were evaluated for a new Flight Controller. The Flight Control Law were optimized and designed for the Cessna Citation X flight envelope by combining the Deferential Evolution algorithm, the Linear Quadratic Regulator method, and the Proportional Integral controller during a previous research presented in part 1. The optimal controllers were used to reach satisfactory aircraft’s dynamic and safe flight operations with respect to the augmentation systems’ handling qualities, and design requirements. Furthermore the number of controllers used to control the aircraft in its flight envelope was optimized using the Linear Fractional Representations features. To validate the controller over the whole aircraft flight envelope, the linear stability, eigenvalue, and handling qualities criteria in addition of the nonlinear analysis criteria were investigated during this research to assess the business aircraft for flight control clearance and certification. The optimized gains provide a very good stability margins as the eigenvalue analysis shows that the aircraft has a high stability, and a very good flying qualities of the linear aircraft models are ensured in its entire flight envelope, its robustness is demonstrated with respect to uncertainties due to its mass and center of gravity variations.
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Development and testing of airfoils for high-altitude aircraft
Drela, Mark (Principal Investigator)
1996-01-01
Specific tasks included airfoil design; study of airfoil constraints on pullout maneuver; selection of tail airfoils; examination of wing twist; test section instrumentation and layout; and integrated airfoil/heat-exchanger tests. In the course of designing the airfoil, specifically for the APEX test vehicle, extensive studies were made over the Mach and Reynolds number ranges of interest. It is intended to be representative of airfoils required for lightweight aircraft operating at extreme altitudes, which is the primary research objective of the APEX program. Also considered were thickness, pitching moment, and off-design behavior. The maximum ceiling parameter M(exp 2)C(sub L) value achievable by the Apex-16 airfoil was found to be a strong constraint on the pullout maneuver. The NACA 1410 and 2410 airfoils (inverted) were identified as good candidates for the tail, with predictable behavior at low Reynolds numbers and good tolerance to flap deflections. With regards to wing twist, it was decided that a simple flat wing was a reasonable compromise. The test section instrumentation consisted of surface pressure taps, wake rakes, surface-mounted microphones, and skin-friction gauges. Also, a modest wind tunnel test was performed for an integrated airfoil/heat-exchanger configuration, which is currently on Aurora's 'Theseus' aircraft. Although not directly related to the APEX tests, the aerodynamics or heat exchangers has been identified as a crucial aspect of designing high-altitude aircraft and hence is relevant to the ERAST program.
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Drag Reduction Devices for Aircraft (Latest Citations from the Aerospace Database)
1996-01-01
The bibliography contains citations concerning the modeling, application, testing, and development of drag reduction devices for aircraft. Slots, flaps, fences, large-eddy breakup (LEBU) devices, vortex generators and turbines, Helmholtz resonators, and winglets are among the devices discussed. Contour shaping to ensure laminar flow, control boundary layer transition, or minimize turbulence is also covered. Applications include the wings, nacelles, fuselage, empennage, and externals of aircraft designed for high-lift, subsonic, or supersonic operation. The design, testing, and development of directional grooves, commonly called riblets, are covered in a separate bibliography.(Contains 50-250 citations and includes a subject term index and title list.)
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Small Aircraft Transportation System, Higher Volume Operations Concept: Off-Nominal Operations
Abbott, Terence S.; Consiglio, Maria C.; Baxley, Brian T.; Williams, Daniel M.; Conway, Sheila R.
2005-01-01
This document expands the Small Aircraft Transportation System, (SATS) Higher Volume Operations (HVO) concept to include off-nominal conditions. The general philosophy underlying the HVO concept is the establishment of a newly defined area of flight operations called a Self-Controlled Area (SCA). During periods of poor weather, a block of airspace would be established around designated non-towered, non-radar airports. Aircraft flying enroute to a SATS airport would be on a standard instrument flight rules flight clearance with Air Traffic Control providing separation services. Within the SCA, pilots would take responsibility for separation assurance between their aircraft and other similarly equipped aircraft. Previous work developed the procedures for normal HVO operations. This document provides details for off-nominal and emergency procedures for situations that could be expected to occur in a future SCA.
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Njoya Motapon, Souleman
As the aircraft industries are moving toward more electric aircraft (MEA), the electrical peak load seen by the main and emergency generators becomes higher than in conventional aircraft. Consequently, there is a major concern regarding the aircraft emergency system, which consists of a ram air turbine (RAT) or air driven generator (ADG), to fulfill the load demand during critical situations; particularly at low aircraft speed where the output power is very low. A potential solution under study by most aircraft manufacturers is to replace the air turbine by a fuel cell hybrid system, consisting of fuel cell combined with other high power density sources such as supercapacitors or lithium-ion batteries. To ensure the fuel cell hybrid system will be able to meet the load demand, it must be properly designed and an effective energy management strategy must be tested with real situations load profile. This work aims at designing a fuel cell emergency power system of a more electric aircraft and comparing different energy management schemes (EMS); with the goal to ensure the load demand is fully satisfied within the constraints of each energy source. The fuel cell hybrid system considered in this study consists of fuel cell, lithium-ion batteries and supercapacitors, along with associated DC-DC and DC-AC converters. The energy management schemes addressed are state-of-the-art, most commonly used energy management techniques in fuel cell vehicle applications and include: the state machine control strategy, the rule based fuzzy logic strategy, the classical PI control strategy, the frequency decoupling/fuzzy logic control strategy and the equivalent consumption minimization strategy (ECMS). Moreover, a new optimal scheme based on maximizing the instantaneous energy of batteries/supercapacitors, to improve the fuel economy is proposed. An off-line optimization based scheme is also developed to ascertain the validity of the proposed strategy in terms of fuel consumption
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An Enhanced Vacuum Cure Technique for On-Aircraft Repair of Carbon-Bismaleimide Composites
Rider, Andrew N.; Baker, Alan A.; Wang, Chun H.; Smith, Graeme
2011-06-01
Carbon/bismaleimide (BMI) composite is increasingly employed in critical load carrying aircraft structures designed to operate at temperatures approaching 180°C. The high post-cure temperature (above 220°C) required to fully react the BMI resin, however, renders existing on-aircraft prepreg or wet layup repair methods invalid. This paper presents a new on-aircraft repair technique for carbon/BMI composites. The composite prepregs are first warm-staged to improve the ability to evacuate entrapped air. Then the patch is cured in the scarf cavity using the vacuum bag technique, followed by off-aircraft post-cure. The fully cured patch then can be bonded using a structural adhesive.
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Application of Powered High Lift Systems to STOL Aircraft Design.
1979-09-01
century by da Vinci, an English - man named Sir George Cayley first attempted to integrate the features of the helicopter and the airplane. In 1843 his...horizontal flight Jun 1959 WEIGHT: 6500 LBS ENGINES: (1) SNECMA ATAR 101 E.V. Turbojet of 8155 lbs thrust LAYOUT: See Fig. 21 COMMENTS: SNECMA was engaged...34 ATAR VOLANT" test vehicle fitted with an annular wing to permit transition to horizontal flight. The aircraft was controlled from a tilting ejec- tion
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Small Aircraft Data Distribution System
Chazanoff, Seth L.; Dinardo, Steven J.
2012-01-01
The CARVE Small Aircraft Data Distribution System acquires the aircraft location and attitude data that is required by the various programs running on a distributed network. This system distributes the data it acquires to the data acquisition programs for inclusion in their data files. It uses UDP (User Datagram Protocol) to broadcast data over a LAN (Local Area Network) to any programs that might have a use for the data. The program is easily adaptable to acquire additional data and log that data to disk. The current version also drives displays using precision pitch and roll information to aid the pilot in maintaining a level-level attitude for radar/radiometer mapping beyond the degree available by flying visually or using a standard gyro-driven attitude indicator. The software is designed to acquire an array of data to help the mission manager make real-time decisions as to the effectiveness of the flight. This data is displayed for the mission manager and broadcast to the other experiments on the aircraft for inclusion in their data files. The program also drives real-time precision pitch and roll displays for the pilot and copilot to aid them in maintaining the desired attitude, when required, during data acquisition on mapping lines.
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75 FR 61655 - Airworthiness Directives; Piper Aircraft, Inc. Model PA-28-161 Airplanes
2010-10-06
...-1006; Directorate Identifier 2009-CE-057-AD] RIN 2120-AA64 Airworthiness Directives; Piper Aircraft... airworthiness directive (AD) for all Piper Aircraft, Inc. (Piper) Model PA-28-161 airplanes equipped with.... Piper Model PA-28-161 airplanes modified by STC No. SA03303AT have a similar unsafe design feature that...
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Autonomous search and surveillance with small fixed wing aircraft
McGee, Timothy Garland
Small unmanned aerial vehicles (UAVs) have the potential to act as low cost tools in a variety of both civilian and military applications including traffic monitoring, border patrol, and search and rescue. While most current operational UAV systems require human operators, advances in autonomy will allow these systems to reach their full potential as sensor platforms. This dissertation specifically focuses on developing advanced control, path planning, search, and image processing techniques that allow small fixed wing aircraft to autonomously collect data. The problems explored were motivated by experience with the development and experimental flight testing of a fleet of small autonomous fixed wing aircraft. These issues, which have not been fully addressed in past work done on ground vehicles or autonomous helicopters, include the influence of wind and turning rate constraints, the non-negligible velocity of ground targets relative to the aircraft velocity, and limitations on sensor size and processing power on small vehicles. Several contributions for the autonomous operation of small fixed wing aircraft are presented. Several sliding surface controllers are designed which extend previous techniques to include variable sliding surface coefficients and the use of spatial vehicle dynamics. These advances eliminate potential singularities in the control laws to follow spatially defined paths and allow smooth transition between controllers. The optimal solution for the problem of path planning through an ordered set of points for an aircraft with a bounded turning rate in the presence of a constant wind is then discussed. Path planning strategies are also explored to guarantee that a searcher will travel within sensing distance of a mobile ground target. This work assumes only a maximum velocity of the target and is designed to succeed for any possible path of the target. Closed-loop approximations of both the path planning and search techniques, using the sliding
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Comprehensive analysis of transport aircraft flight performance
Filippone, Antonio
2008-04-01
This paper reviews the state-of-the art in comprehensive performance codes for fixed-wing aircraft. The importance of system analysis in flight performance is discussed. The paper highlights the role of aerodynamics, propulsion, flight mechanics, aeroacoustics, flight operation, numerical optimisation, stochastic methods and numerical analysis. The latter discipline is used to investigate the sensitivities of the sub-systems to uncertainties in critical state parameters or functional parameters. The paper discusses critically the data used for performance analysis, and the areas where progress is required. Comprehensive analysis codes can be used for mission fuel planning, envelope exploration, competition analysis, a wide variety of environmental studies, marketing analysis, aircraft certification and conceptual aircraft design. A comprehensive program that uses the multi-disciplinary approach for transport aircraft is presented. The model includes a geometry deck, a separate engine input deck with the main parameters, a database of engine performance from an independent simulation, and an operational deck. The comprehensive code has modules for deriving the geometry from bitmap files, an aerodynamics model for all flight conditions, a flight mechanics model for flight envelopes and mission analysis, an aircraft noise model and engine emissions. The model is validated at different levels. Validation of the aerodynamic model is done against the scale models DLR-F4 and F6. A general model analysis and flight envelope exploration are shown for the Boeing B-777-300 with GE-90 turbofan engines with intermediate passenger capacity (394 passengers in 2 classes). Validation of the flight model is done by sensitivity analysis on the wetted area (or profile drag), on the specific air range, the brake-release gross weight and the aircraft noise. A variety of results is shown, including specific air range charts, take-off weight-altitude charts, payload-range performance
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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.
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THE PROBLEMS OF PERFORMANCE MONITORING TO TAKLE THE TASKS OF THE AIRCRAFT CONTINUED AIRWORTHINESS
Directory of Open Access Journals (Sweden)
Yu. M. Chinyuchin
2017-01-01
Full Text Available Improving of the aircraft continued airworthiness system is currently becoming of particular importance applied both to aircraft of domestic and foreign production, used in civil aviation of Russia. This article discusses the background and content of the tasks for long-haul aircraft continued airworthiness, which presents a challenge directly related to the provision of intensive, regular, economically viable, and safe operation of assigned airline fleet. A special place among the problems of continued airworthiness is held by the creation and organization of mechanisms and methods of resource status and age of the assigned airline fleet monitoring to manage its forecasting and timely updates. Not least important among the issues of resource and age structure monitoring to be considered is the need to improve the design of aircraft, taking into account preliminary technical and economic feasibility assessment of its modifications in the interests of the operator. A deep study of the contents of the monitoring allows to develop up-to-date methodological and scientific basis for building an integrated system of aircraft resource management and timing services. This system is developed based on the integrated approach that allows to provide a solution to the entire set of problems presented in this article and faced by professionals and scientists involved in the aircraft maintenance programs development on the stages of their design and manufacturing and long operation of aircraft continued airworthiness.
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Integrated Design of a Long-Haul Commercial Aircraft Optimized for Formation Flying
Dijkers, H.P.A.; Van Nunen, R.; Bos, D.A.; Gutleb, T.L.M.; Herinckx, L.E.; Radfar, H.; Van Rompuy, E.; Sayin, S.E.; De Wit, J.; Beelaerts van Blokland, W.W.A.
2011-01-01
The airline industry is under continuous pressure to reduce emissions and costs. This paper investigates the feasibility for commercial airlines to use formation flight to reduce emissions and fuel burn. To fly in formation, an aircraft needs to benefit from the wake vortices of the preceding
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Health and usage monitoring system for the small aircraft composite structure
Růžička, Milan; Dvořák, Milan; Schmidová, Nikola; Šašek, Ladislav; Štěpánek, Martin
2017-07-01
This paper is focused on the design of the health and usage monitoring system (HUMS) of the composite ultra-light aircrafts. A multichannel measuring system was developed and installed for recording of the long-term operational measurements of the UL airplane. Many fiber Bragg grating sensors were implemented into the composite aircraft structure, mainly in the glue joints. More than ten other analog functions and signals of the aircraft is monitored and can be correlated together. Changing of the FBG sensors responses in monitored places and their correlations, comparing with the calibration and recalibration procedures during a monitored life may indicate damage (eg. in bonded joints) and complements the HUMS system.
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Landing Gear Noise Prediction and Analysis for Tube-and-Wing and Hybrid-Wing-Body Aircraft
Guo, Yueping; Burley, Casey L.; Thomas, Russell H.
2016-01-01
Improvements and extensions to landing gear noise prediction methods are developed. New features include installation effects such as reflection from the aircraft, gear truck angle effect, local flow calculation at the landing gear locations, gear size effect, and directivity for various gear designs. These new features have not only significantly improved the accuracy and robustness of the prediction tools, but also have enabled applications to unconventional aircraft designs and installations. Systematic validations of the improved prediction capability are then presented, including parametric validations in functional trends as well as validations in absolute amplitudes, covering a wide variety of landing gear designs, sizes, and testing conditions. The new method is then applied to selected concept aircraft configurations in the portfolio of the NASA Environmentally Responsible Aviation Project envisioned for the timeframe of 2025. The landing gear noise levels are on the order of 2 to 4 dB higher than previously reported predictions due to increased fidelity in accounting for installation effects and gear design details. With the new method, it is now possible to reveal and assess the unique noise characteristics of landing gear systems for each type of aircraft. To address the inevitable uncertainties in predictions of landing gear noise models for future aircraft, an uncertainty analysis is given, using the method of Monte Carlo simulation. The standard deviation of the uncertainty in predicting the absolute level of landing gear noise is quantified and determined to be 1.4 EPNL dB.
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Quasi-ADS-B Based UAV Conflict Detection and Resolution to Manned Aircraft
Directory of Open Access Journals (Sweden)
Chin E. Lin
2015-01-01
Full Text Available A Conflict Detection and Resolution (CD&R system for manned/unmanned aerial vehicle (UAV based on Automatic Dependent Surveillance-Broadcast (ADS-B concept is designed and verified in this paper. The 900 MHz XBee-Pro is selected as data transponder to broadcast flight information among participating aircraft in omnirange. Standard Compact Position Report (CPR format packet data are automatically broadcasted by ID sequencing under Quasi-ADS-B mechanism. Time Division Multiple Access (TDMA monitoring checks the designated time slot and reallocates the conflict ID. This mechanism allows the transponder to effectively share data with multiple aircraft in near airspace. The STM32f103 microprocessor is designed to handle RF, GPS, and flight data with Windows application on manned aircraft and ground control station simultaneously. Different conflict detection and collision avoidance algorithms can be implemented into the system to ensure flight safety. The proposed UAV/CD&R using Quasi-ADS-B transceiver is tested using ultralight aircraft flying at 100–120 km/hr speed in small airspace for mission simulation. The proposed hardware is also useful to additional applications to mountain hikers for emergency search and rescue. The fundamental function by the proposed UAV/CD&R using Quasi-ADS-B is verified with effective signal broadcasting for surveillance and efficient collision alert and avoidance performance to low altitude flights.
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Experimental Study of Turbine Fuel Thermal Stability in an Aircraft Fuel System Simulator
Vranos, A.; Marteney, P. J.
1980-01-01
The thermal stability of aircraft gas turbines fuels was investigated. The objectives were: (1) to design and build an aircraft fuel system simulator; (2) to establish criteria for quantitative assessment of fuel thermal degradation; and (3) to measure the thermal degradation of Jet A and an alternative fuel. Accordingly, an aircraft fuel system simulator was built and the coking tendencies of Jet A and a model alternative fuel (No. 2 heating oil) were measured over a range of temperatures, pressures, flows, and fuel inlet conditions.
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Nonparametric method for failures diagnosis in the actuating subsystem of aircraft control system
Terentev, M. N.; Karpenko, S. S.; Zybin, E. Yu; Kosyanchuk, V. V.
2018-02-01
In this paper we design a nonparametric method for failures diagnosis in the aircraft control system that uses the measurements of the control signals and the aircraft states only. It doesn’t require a priori information of the aircraft model parameters, training or statistical calculations, and is based on analytical nonparametric one-step-ahead state prediction approach. This makes it possible to predict the behavior of unidentified and failure dynamic systems, to weaken the requirements to control signals, and to reduce the diagnostic time and problem complexity.
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Multidisciplinary Shape Optimization of a Composite Blended Wing Body Aircraft
Boozer, Charles Maxwell
A multidisciplinary shape optimization tool coupling aerodynamics, structure, and performance was developed for battery powered aircraft. Utilizing high-fidelity computational fluid dynamics analysis tools and a structural wing weight tool, coupled based on the multidisciplinary feasible optimization architecture; aircraft geometry is modified in the optimization of the aircraft's range or endurance. The developed tool is applied to three geometries: a hybrid blended wing body, delta wing UAS, the ONERA M6 wing, and a modified ONERA M6 wing. First, the optimization problem is presented with the objective function, constraints, and design vector. Next, the tool's architecture and the analysis tools that are utilized are described. Finally, various optimizations are described and their results analyzed for all test subjects. Results show that less computationally expensive inviscid optimizations yield positive performance improvements using planform, airfoil, and three-dimensional degrees of freedom. From the results obtained through a series of optimizations, it is concluded that the newly developed tool is both effective at improving performance and serves as a platform ready to receive additional performance modules, further improving its computational design support potential.
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What makes a space invader? Passenger perceptions of personal space invasion in aircraft travel.
Lewis, Laura; Patel, Harshada; D'Cruz, Mirabelle; Cobb, Sue
2017-11-01
The invasion of personal space is often a contributory factor to the experience of discomfort in aircraft passengers. This paper presents a questionnaire study which investigated how air travellers are affected by invasions of personal space and how they attempt to adapt to, or counter, these invasions. In support of recent findings on the factors influencing air passenger comfort, the results of this study indicate that the invasion of personal space is not only caused by physical factors (e.g. physical contact with humans or objects), but also other sensory factors such as noise, smells or unwanted eye contact. The findings of this study have implications for the design of shared spaces. Practitioner Summary: This paper presents a questionnaire study which investigated personal space in an aircraft environment. The results highlight the factors which affect the perception of personal space invasion in aircraft and can therefore inform the design of aircraft cabin environments to enhance the passenger experience.
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Preliminary Correlations for Remotely Piloted Aircraft Systems Sizing
Directory of Open Access Journals (Sweden)
Álvaro Gómez-Rodríguez
2018-01-01
Full Text Available The field of Remotely Piloted Aircraft Systems (RPAS is currently undergoing a noteworthy expansion. The diverse types of missions that these aircraft can accomplish, both in military and civil environments, have motivated an increase of interest in their study and applications. The methods chosen to develop this study are based on the statistical analysis of a database including numerous models of RPAS and the estimation of different correlations in order to develop a design method for rapid sizing of H-tail RPAS. Organizing the information of the database according to relevant characteristics, information relative to the state-of-the-art design tendencies can be extracted, which can serve to take decisions relative to the aerodynamic configuration or the power plant in the first phases of the design project. Furthermore, employing statistical correlations estimated from the database, a design method for rapid-sizing of H-tail RPAS has been conducted, which will be focused on the sizing of the wing and tail surfaces. The resulting method has been tested by applying it to an example case so as to validate the proposed procedure.
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Smith, G. A.; Meyer, G.
1980-01-01
The results of a simulation study of an alternative design concept for an automatic landing control system are presented. The alternative design concept for an automatic landing control system is described. The design concept is the total aircraft flight control system (TAFCOS). TAFCOS is an open loop, feed forward system that commands the proper instantaneous thrust, angle of attack, and roll angle to achieve the forces required to follow the desired trajector. These dynamic trim conditions are determined by an inversion of the aircraft nonlinear force characteristics. The concept was applied to an A-7E aircraft approaching an aircraft carrier. The implementation details with an airborne digital computer are discussed. The automatic carrier landing situation is described. The simulation results are presented for a carrier approach with atmospheric disturbances, an approach with no disturbances, and for tailwind and headwind gusts.
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X-36 Tailless Fighter Agility Research Aircraft arrival at Dryden
1996-01-01
The NASA/McDonnell Douglas Corporation (MDC) X-36 Tailless Fighter Agility Research Aircraft in it's hangar at NASA Dryden Flight Research Center, Edwards, California, following its arrival on July 2, 1996. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three feet high with a wingspan of
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Water Supply Systems For Aircraft Fire And Rescue Protection
1995-01-01
This Advisory Circular (AC) provides guidance for the selection : of a water source and standards for the design of a distribution system to : support aircraft rescue and fire fighting (ARFF) service operations on : airports.
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High temperature aircraft research furnace facilities
Smith, James E., Jr.; Cashon, John L.
1992-01-01
Focus is on the design, fabrication, and development of the High Temperature Aircraft Research Furnace Facilities (HTARFF). The HTARFF was developed to process electrically conductive materials with high melting points in a low gravity environment. The basic principle of operation is to accurately translate a high temperature arc-plasma gas front as it orbits around a cylindrical sample, thereby making it possible to precisely traverse the entire surface of a sample. The furnace utilizes the gas-tungsten-arc-welding (GTAW) process, also commonly referred to as Tungsten-Inert-Gas (TIG). The HTARFF was developed to further research efforts in the areas of directional solidification, float-zone processing, welding in a low-gravity environment, and segregation effects in metals. The furnace is intended for use aboard the NASA-JSC Reduced Gravity Program KC-135A Aircraft.
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Energy Technology Data Exchange (ETDEWEB)
Knapp, W.
1997-05-01
The article describes the solar aircraft `Icare`` which was constucted in a joint project by engineers and scientists of Stuttgart university. The aircraft requires slightly more than one kW for staying up. The theoretical fundamentals are presented in the dissertation of Peer Frank, ``Aircraft design for minimum fuel consumption` (Institute of Aircraft Engineering, Stuttgart, 1992). (orig.) [Deutsch] Allein mit Sonnenkraft kann das Flugzeug `Icare` fliegen. Es entstand in Gemeinschaftsarbeit von Ingenieuren und Wissenschaftlern der Stuttgarter Universitaet. Das Solarflugzeug Icare benoetigt etwas ueber ein Kilowatt, um oben zu bleiben. In seiner Doktorarbeit `Die Auslegung von Flugzeugen mit geringstem Antriebsleistungsbedarf` (Institut fuer Flugzeugbau, Stuttgart, 1992) hat der Duesseldorfer Peer Frank die theoretischen Grundlagen dazu behandelt. (orig.)
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1975-01-01
The results are presented of a risk assessment study conducted on two technology aircraft. The aircraft system components were reviewed and assessed for risk based on: (1) complexity relative to state-of-the-art, (2) manufacturing and qualification testing, (3) availability and delays, and (4) cost/schedule impact. These assessments were based on five risk nomenclatures: low, minor, moderate, high, and extreme. Each aircraft system was assigned an overall risk rating depending upon its contribution to the capability of the aircraft to achieve the performance goals. The slightly lower Sabreliner performance margin is due to the restricted flight envelope, the fixed landing gear, and internal fuel capacity. The Sabreliner with retractable gear and allowed to fly at its best speed and altitude would reflect performance margins similar to the New Airframe. These significant margins, inherent with the MCAIR three gas generator/three fan propulsion system, are major modifiers to risk assessment of both aircraft. The estimated risk and the associated key system and performance areas are tabulated.
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Directory of Open Access Journals (Sweden)
Matei POPA
2010-03-01
Full Text Available In accordance with Air Force requirements, the comparative analysis of short/medium transport aircraft comes to sustain procurement decision of short/medium transport aircraft. This paper presents, in short, the principles and the results of the comparative analysis for short/medium military transport aircraft.
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Aircraft Engine Technology for Green Aviation to Reduce Fuel Burn
Hughes, Christopher E.; VanZante, Dale E.; Heidmann, James D.
2013-01-01
The NASA Fundamental Aeronautics Program Subsonic Fixed Wing Project and Integrated Systems Research Program Environmentally Responsible Aviation Project in the Aeronautics Research Mission Directorate are conducting research on advanced aircraft technology to address the environmental goals of reducing fuel burn, noise and NOx emissions for aircraft in 2020 and beyond. Both Projects, in collaborative partnerships with U.S. Industry, Academia, and other Government Agencies, have made significant progress toward reaching the N+2 (2020) and N+3 (beyond 2025) installed fuel burn goals by fundamental aircraft engine technology development, subscale component experimental investigations, full scale integrated systems validation testing, and development validation of state of the art computation design and analysis codes. Specific areas of propulsion technology research are discussed and progress to date.
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Finite Element Analysis of Composite Aircraft Fuselage Frame
Dandekar, Aditya Milind
Composites have been introduced in aircraft industries, for their stronger, stiffer, and lighter properties than their metal-alloys counterparts. The general purpose of an aircraft is to transport commercial or military payload. Aircraft frames primarily maintains the shape of fuselage and prevent instability of the structure. Fuselage is similar as wing in construction which consist of longitudinal elements (longerons and stringers), transverse elements (frames and bulkheads) and its external skin. The fuselage is subjected to forces such as the wing reactions, landing gear reaction, empennage reaction, inertia forces subjected due to size and weight, internal pressure forces due to high altitude. Frames also ensure fail-safe design against skin crack propagation due to hoops stress. Ideal fuselage frames cross section is often circular ring shape with a frame cap of Z section. They are mainly made up of light alloy commonly used is aluminium alloys such as Al-2024, Al-7010, Al-7050, Al-7175. Aluminium alloys have good strength to density ratios in compression and bending of thin plate. A high strength to weight ratio of composite materials can result in a lighter aircraft structure or better safety factor. This research focuses on analysis of fuselage frame under dynamic load condition with change in material. Composites like carbon fibre reinforced plastics [CFRP] and glass fibre reinforced plastics [GFRP] are compared with traditional aluminium alloy Al-7075. The frame is subjected to impact test by dropping it at a velocity of 30 ft. / secs from a height of 86 inch from its centre of gravity. These parameters are considered in event of failure of landing gear, and an aircraft is subject to belly landing or gear-up landing. The shear flow is calculated due to impact force which acts in radial direction. The frame is analysed under static structural and explicit dynamic load conditions. Geometry is created in ANSYS Design Modeler. Analysis setup is created using
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Adaptive Backstepping Flight Control for Modern Fighter Aircraft
Sonneveldt, L.
2010-01-01
The main goal of this thesis is to investigate the potential of the nonlinear adaptive backstepping control technique in combination with online model identification for the design of a reconfigurable flight control system for a modern fighter aircraft. Adaptive backstepping is a recursive,
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Aircraft interrogation and display system: A ground support equipment for digital flight systems
Glover, R. D.
1982-01-01
A microprocessor-based general purpose ground support equipment for electronic systems was developed. The hardware and software are designed to permit diverse applications in support of aircraft flight systems and simulation facilities. The implementation of the hardware, the structure of the software, describes the application of the system to an ongoing research aircraft project are described.
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Imaged-Based Visual Servo Control for a VTOL Aircraft
Directory of Open Access Journals (Sweden)
Liying Zou
2017-01-01
Full Text Available This paper presents a novel control strategy to force a vertical take-off and landing (VTOL aircraft to accomplish the pinpoint landing task. The control development is based on the image-based visual servoing method and the back-stepping technique; its design differs from the existing methods because the controller maps the image errors onto the actuator space via a visual model which does not contain the depth information of the feature point. The novelty of the proposed method is to extend the image-based visual servoing technique to the VTOL aircraft control. In addition, the Lyapunov theory is used to prove the asymptotic stability of the VTOL aircraft visual servoing system, while the image error can converge to zero. Furthermore, simulations have been also conducted to demonstrate the performances of the proposed method.
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Multidisciplinary Conceptual Design for Reduced-Emission Rotorcraft
Silva, Christopher; Johnson, Wayne; Solis, Eduardo
2018-01-01
Python-based wrappers for OpenMDAO are used to integrate disparate software for practical conceptual design of rotorcraft. The suite of tools which are connected thus far include aircraft sizing, comprehensive analysis, and parametric geometry. The tools are exercised to design aircraft with aggressive goals for emission reductions relative to fielded state-of-the-art rotorcraft. Several advanced reduced-emission rotorcraft are designed and analyzed, demonstrating the flexibility of the tools to consider a wide variety of potentially transformative vertical flight vehicles. To explore scale effects, aircraft have been sized for 5, 24, or 76 passengers in their design missions. Aircraft types evaluated include tiltrotor, single-main-rotor, coaxial, and side-by-side helicopters. Energy and drive systems modeled include Lithium-ion battery, hydrogen fuel cell, turboelectric hybrid, and turboshaft drive systems. Observations include the complex nature of the trade space for this simple problem, with many potential aircraft design and operational solutions for achieving significant emission reductions. Also interesting is that achieving greatly reduced emissions may not require exotic component technologies, but may be achieved with a dedicated design objective of reducing emissions.
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Aircraft operations management manual
1992-01-01
The NASA aircraft operations program is a multifaceted, highly diverse entity that directly supports the agency mission in aeronautical research and development, space science and applications, space flight, astronaut readiness training, and related activities through research and development, program support, and mission management aircraft operations flights. Users of the program are interagency, inter-government, international, and the business community. This manual provides guidelines to establish policy for the management of NASA aircraft resources, aircraft operations, and related matters. This policy is an integral part of and must be followed when establishing field installation policy and procedures covering the management of NASA aircraft operations. Each operating location will develop appropriate local procedures that conform with the requirements of this handbook. This manual should be used in conjunction with other governing instructions, handbooks, and manuals.
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Systems Analysis Initiated for All-Electric Aircraft Propulsion
Kohout, Lisa L.
2003-01-01
A multidisciplinary effort is underway at the NASA Glenn Research Center to develop concepts for revolutionary, nontraditional fuel cell power and propulsion systems for aircraft applications. There is a growing interest in the use of fuel cells as a power source for electric propulsion as well as an auxiliary power unit to substantially reduce or eliminate environmentally harmful emissions. A systems analysis effort was initiated to assess potential concepts in an effort to identify those configurations with the highest payoff potential. Among the technologies under consideration are advanced proton exchange membrane (PEM) and solid oxide fuel cells, alternative fuels and fuel processing, and fuel storage. Prior to this effort, the majority of fuel cell analysis done at Glenn was done for space applications. Because of this, a new suite of models was developed. These models include the hydrogen-air PEM fuel cell; internal reforming solid oxide fuel cell; balance-of-plant components (compressor, humidifier, separator, and heat exchangers); compressed gas, cryogenic, and liquid fuel storage tanks; and gas turbine/generator models for hybrid system applications. Initial mass, volume, and performance estimates of a variety of PEM systems operating on hydrogen and reformate have been completed for a baseline general aviation aircraft. Solid oxide/turbine hybrid systems are being analyzed. In conjunction with the analysis efforts, a joint effort has been initiated with Glenn s Computer Services Division to integrate fuel cell stack and component models with the visualization environment that supports the GRUVE lab, Glenn s virtual reality facility. The objective of this work is to provide an environment to assist engineers in the integration of fuel cell propulsion systems into aircraft and provide a better understanding of the interaction between system components and the resulting effect on the overall design and performance of the aircraft. Initially, three
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Bifurcation analysis and stability design for aircraft longitudinal motion with high angle of attack
Directory of Open Access Journals (Sweden)
Xin Qi
2015-02-01
Full Text Available Bifurcation analysis and stability design for aircraft longitudinal motion are investigated when the nonlinearity in flight dynamics takes place severely at high angle of attack regime. To predict the special nonlinear flight phenomena, bifurcation theory and continuation method are employed to systematically analyze the nonlinear motions. With the refinement of the flight dynamics for F-8 Crusader longitudinal motion, a framework is derived to identify the stationary bifurcation and dynamic bifurcation for high-dimensional system. Case study shows that the F-8 longitudinal motion undergoes saddle node bifurcation, Hopf bifurcation, Zero-Hopf bifurcation and branch point bifurcation under certain conditions. Moreover, the Hopf bifurcation renders series of multiple frequency pitch oscillation phenomena, which deteriorate the flight control stability severely. To relieve the adverse effects of these phenomena, a stabilization control based on gain scheduling and polynomial fitting for F-8 longitudinal motion is presented to enlarge the flight envelope. Simulation results validate the effectiveness of the proposed scheme.
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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.
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REPAIR TECHNOLOGY OF THE COMPOSITE WING OF A LIGHT PLANE DAMAGED DURING AN AIRCRAFT CRASH
Directory of Open Access Journals (Sweden)
Andrzej ŚWIĄTONIOWSKI
2016-09-01
Full Text Available The increasing use of composite structures in aircraft constructions has made it necessary to develop repair methods that will restore the component’s original design strength without compromising its structural integrity. In this paper, the complex repair technology of the composite wing of a light plane, which was damaged during an aircraft crash, is described. The applied repair scheme should meet all the original design requirements for the plane structure.
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Challenges of Aircraft Design Integration
2003-03-01
predicted by the conceptual stick model and the full FEM of the Challenger wing without winglets . Advanced aerodynamic wing design methods To design wings...Piperni, E. Laurendeau Advanced Aerodynamics Bombardier Aerospace 400 CMte Vertu Road Dorval, Quebec, Canada, H4S 1Y9 Fassi.Kafyeke @notes.canadair.ca Tel...514) 855-7186 Abstract The design of a modern airplane brings together many disciplines: structures, aerodynamics , controls, systems, propulsion
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Regulatory Analysis on the Safety Assessment of NPPs against Aircraft Crash
International Nuclear Information System (INIS)
Kim, Sang Yun; Park, Jong Seuk; Chung, Yun Suk; Jung, Rae Young
2011-01-01
Following the 9/11 terror, a new regulation (10CFR 50.150) was enacted in June 2009 in the United States mandating the assessment of new nuclear power plants (NPPs) against intentional aircraft crashes, along with a regulation (10CFR 50.54 (h)(h)) in March 2009 that requires the establishment of accident mitigation measures for NPPs in operation. The UAE requested that the Korean NPP (APR 1400) design meet the U.S.'s new requirements related to the intentional aircraft crash. During the UAE NPP contract bidding process, France claimed that the Korean NPP is vulnerable to aircraft crashes comparing with the French NPP (EPR). Under these international and domestic environments, the necessity to establish a domestic regulation concerning the intentional aircraft crash was raised. This paper proposes a draft regulatory position on this issue through a comprehensive analysis of various influencing factors
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METHOD IMPROVEMENT FOR DETERMINING THE TECHNICAL LEVEL OF CIVIL AIRCRAFT
Directory of Open Access Journals (Sweden)
2016-01-01
Full Text Available Aircraft are high-tech engineering products which are characterized by a wide range of properties including the two most important groups that respectively characterize the efficiency and technical level.Improving the aircraft efficiency is an essential factor for air transport development, but the efficiency can not be fully describe the technical system, especially in forecasting and new technology requirements development. Aircraft de- signer must evaluate the prospects of a technical solution, but it’s not always possible to calculate the efficiency accuratelyat the design stage. The operator should be able to choose the most technically-advanced aircraft available in the market inorder not to let it grow obsolete quickly. This determines the need for non-economic evaluation of technical systems that can be done by assessment of their technical level.The technical level is a general index that includes a set of technical perfection indicators. Technical perfection is reflected in terms of material and energy intensity, in terms of ergonomics, safety, etc. and is achieved as a result of origi- nal design solutions, the use of new high-strength low-density materials, the introduction of advanced technological pro-cesses, calculation methods, verification, testing, etc.There is a tight connection between the product properties and its weight, because weight is the material reflection of these properties. Therefore, improvement of the product properties usually leads to an intense increase of its weight. To deal with this phenomenon is only possible with widely using scientific and technical progress results. In accordance with this, the technical perfection can be interpreted as a major component of quality that is created without the weight increase. This approach requires investment in research and testing new technical solutions.The method was developed to determine the technical level of civil long-haul aircraft which has been modified to
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The Low-Noise Potential of Distributed Propulsion on a Catamaran Aircraft
Posey, Joe W.; Tinetti, A. F.; Dunn, M. H.
2006-01-01
The noise shielding potential of an inboard-wing catamaran aircraft when coupled with distributed propulsion is examined. Here, only low-frequency jet noise from mid-wing-mounted engines is considered. Because low frequencies are the most difficult to shield, these calculations put a lower bound on the potential shielding benefit. In this proof-of-concept study, simple physical models are used to describe the 3-D scattering of jet noise by conceptualized catamaran aircraft. The Fast Scattering Code is used to predict noise levels on and about the aircraft. Shielding results are presented for several catamaran type geometries and simple noise source configurations representative of distributed propulsion radiation. Computational analyses are presented that demonstrate the shielding benefits of distributed propulsion and of increasing the width of the inboard wing. Also, sample calculations using the FSC are presented that demonstrate additional noise reduction on the aircraft fuselage by the use of acoustic liners on the inboard wing trailing edge. A full conceptual aircraft design would have to be analyzed over a complete mission to more accurately quantify community noise levels and aircraft performance, but the present shielding calculations show that a large acoustic benefit could be achieved by combining distributed propulsion and liner technology with a twin-fuselage planform.
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Bennett, Charles L.
2007-09-18
A solar thermal powered aircraft powered by heat energy from the sun. A heat engine, such as a Stirling engine, is carried by the aircraft body for producing power for a propulsion mechanism, such as a propeller. The heat engine has a thermal battery in thermal contact with it so that heat is supplied from the thermal battery. A solar concentrator, such as reflective parabolic trough, is movably connected to an optically transparent section of the aircraft body for receiving and concentrating solar energy from within the aircraft. Concentrated solar energy is collected by a heat collection and transport conduit, and heat transported to the thermal battery. A solar tracker includes a heliostat for determining optimal alignment with the sun, and a drive motor actuating the solar concentrator into optimal alignment with the sun based on a determination by the heliostat.
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Structural Analysis in a Conceptual Design Framework
Padula, Sharon L.; Robinson, Jay H.; Eldred, Lloyd B.
2012-01-01
Supersonic aircraft designers must shape the outer mold line of the aircraft to improve multiple objectives, such as mission performance, cruise efficiency, and sonic-boom signatures. Conceptual designers have demonstrated an ability to assess these objectives for a large number of candidate designs. Other critical objectives and constraints, such as weight, fuel volume, aeroelastic effects, and structural soundness, are more difficult to address during the conceptual design process. The present research adds both static structural analysis and sizing to an existing conceptual design framework. The ultimate goal is to include structural analysis in the multidisciplinary optimization of a supersonic aircraft. Progress towards that goal is discussed and demonstrated.
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Wings: A New Paradigm in Human-Centered Design
Schutte, Paul C.
1997-01-01
Many aircraft accidents/incidents investigations cite crew error as a causal factor (Boeing Commercial Airplane Group 1996). Human factors experts suggest that crew error has many underlying causes and should be the start of an accident investigation and not the end. One of those causes, the flight deck design, is correctable. If a flight deck design does not accommodate the human's unique abilities and deficits, crew error may simply be the manifestation of this mismatch. Pilots repeatedly report that they are "behind the aircraft" , i.e., they do not know what the automated aircraft is doing or how the aircraft is doing it until after the fact. Billings (1991) promotes the concept of "human-centered automation"; calling on designers to allocate appropriate control and information to the human. However, there is much ambiguity regarding what it mean's to be human-centered. What often are labeled as "human-centered designs" are actually designs where a human factors expert has been involved in the design process or designs where tests have shown that humans can operate them. While such designs may be excellent, they do not represent designs that are systematically produced according to some set of prescribed methods and procedures. This paper describes a design concept, called Wings, that offers a clearer definition for human-centered design. This new design concept is radically different from current design processes in that the design begins with the human and uses the human body as a metaphor for designing the aircraft. This is not because the human is the most important part of the aircraft (certainly the aircraft would be useless without lift and thrust), but because he is the least understood, the least programmable, and one of the more critical elements. The Wings design concept has three properties: a reversal in the design process, from aerodynamics-, structures-, and propulsion-centered to truly human-centered; a design metaphor that guides function
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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.)
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Energy management strategy for solar-powered high-altitude long-endurance aircraft
International Nuclear Information System (INIS)
Gao, Xian-Zhong; Hou, Zhong-Xi; Guo, Zheng; Liu, Jian-Xia; Chen, Xiao-Qian
2013-01-01
Highlights: ► A new Energy Management Strategy (EMS) for high-altitude solar-powered aircraft is purposed. ► The simulations show that the aircraft can always keep the altitude above 16 km with the proposed EMS. ► The proposed EMS is capable to alleviate the power consumed for aircraft during night. ► The main technologies to improve the flight performance of aircraft are analyzed. - Abstract: Development of solar-powered High-Altitude Long-Endurance (HALE) aircraft has a great impact on both military and civil aviation industries since its features in high-altitude and energy source can be considered inexhaustible. Owing to the development constraints of rechargeable batteries, the solar-powered HALE aircraft must take amount of rechargeable batteries to fulfill the energy requirement in night, which greatly limits the operation altitude of aircraft. In order to solve this problem, a new Energy Management Strategy (EMS) is proposed based on the idea that the solar energy can be partly stored in gravitational potential in daytime. The flight path of HALE aircraft is divided into three stages. During the stage 1, the solar energy is stored in both lithium–sulfur battery and gravitational potential. The gravitational potential is released in stage 2 by gravitational gliding and the required power in stage 3 is supplied by lithium–sulfur battery. Correspondingly, the EMS is designed for each stage. The simulation results show that the aircraft can always keep the altitude above 16 km with the proposed EMS, and the power consumed during night can be also alleviated. Comparing with the current EMS, about 23.5% energy is remained in batteries with the proposed EMS during one day–night cycle. The sensitivities of the improvement of crucial technologies to the performance of aircraft are also analyzed. The results show that the enhancement of control and structural system, lithium–sulfur battery, and solar cell are ranked in descending order for the
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Non-linear aeroelastic prediction for aircraft applications
de C. Henshaw, M. J.; Badcock, K. J.; Vio, G. A.; Allen, C. B.; Chamberlain, J.; Kaynes, I.; Dimitriadis, G.; Cooper, J. E.; Woodgate, M. A.; Rampurawala, A. M.; Jones, D.; Fenwick, C.; Gaitonde, A. L.; Taylor, N. V.; Amor, D. S.; Eccles, T. A.; Denley, C. J.
2007-05-01
Current industrial practice for the prediction and analysis of flutter relies heavily on linear methods and this has led to overly conservative design and envelope restrictions for aircraft. Although the methods have served the industry well, it is clear that for a number of reasons the inclusion of non-linearity in the mathematical and computational aeroelastic prediction tools is highly desirable. The increase in available and affordable computational resources, together with major advances in algorithms, mean that non-linear aeroelastic tools are now viable within the aircraft design and qualification environment. The Partnership for Unsteady Methods in Aerodynamics (PUMA) Defence and Aerospace Research Partnership (DARP) was sponsored in 2002 to conduct research into non-linear aeroelastic prediction methods and an academic, industry, and government consortium collaborated to address the following objectives: To develop useable methodologies to model and predict non-linear aeroelastic behaviour of complete aircraft. To evaluate the methodologies on real aircraft problems. To investigate the effect of non-linearities on aeroelastic behaviour and to determine which have the greatest effect on the flutter qualification process. These aims have been very effectively met during the course of the programme and the research outputs include: New methods available to industry for use in the flutter prediction process, together with the appropriate coaching of industry engineers. Interesting results in both linear and non-linear aeroelastics, with comprehensive comparison of methods and approaches for challenging problems. Additional embryonic techniques that, with further research, will further improve aeroelastics capability. This paper describes the methods that have been developed and how they are deployable within the industrial environment. We present a thorough review of the PUMA aeroelastics programme together with a comprehensive review of the relevant research
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Assessment of sensors and aircraft for oil spill remote sensing
International Nuclear Information System (INIS)
Fingas, M.F.; Fruhwirth, M.
1993-01-01
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
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International Nuclear Information System (INIS)
Crump, D A; Dulieu-Barton, J M; Savage, J
2010-01-01
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
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Potential for Landing Gear Noise Reduction on Advanced Aircraft Configurations
Thomas, Russell H.; Nickol, Craig L.; Burley, Casey L.; Guo, Yueping
2016-01-01
The potential of significantly reducing aircraft landing gear noise is explored for aircraft configurations with engines installed above the wings or the fuselage. An innovative concept is studied that does not alter the main gear assembly itself but does shorten the main strut and integrates the gear in pods whose interior surfaces are treated with acoustic liner. The concept is meant to achieve maximum noise reduction so that main landing gears can be eliminated as a major source of airframe noise. By applying this concept to an aircraft configuration with 2025 entry-into-service technology levels, it is shown that compared to noise levels of current technology, the main gear noise can be reduced by 10 EPNL dB, bringing the main gear noise close to a floor established by other components such as the nose gear. The assessment of the noise reduction potential accounts for design features for the advanced aircraft configuration and includes the effects of local flow velocity in and around the pods, gear noise reflection from the airframe, and reflection and attenuation from acoustic liner treatment on pod surfaces and doors. A technical roadmap for maturing this concept is discussed, and the possible drag increase at cruise due to the addition of the pods is identified as a challenge, which needs to be quantified and minimized possibly with the combination of detailed design and application of drag reduction technologies.
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Critical joints in large composite primary aircraft structures. Volume 1: Technical summary
Bunin, Bruce L.
1985-01-01
A program was conducted at Douglas Aircraft Company to develop the technology for critical joints in composite wing structure that meets all the design requirements of a 1990 commercial transport aircraft. In fulfilling this objective, analytical procedures for joint design and analysis were developed during Phase 1 of the program. Tests were conducted at the element level to supply the empirical data required for methods development. Large composite multirow joints were tested to verify the selected design concepts and for correlation with analysis predictions. The Phase 2 program included additional tests to provide joint design and analysis data, and culminated with several technology demonstration tests of a major joint area representative of a commercial transport wing. The technology demonstration program of Phase 2 is discussed. The analysis methodology development, structural test program, and correlation between test results and analytical strength predictions are reviewed.
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Long Range Aircraft Trajectory Prediction
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 ...
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Development of an Unmanned Aircraft Systems Program: ACUASI
Webley, P. W.; Cahill, C. F.; Rogers, M.; Hatfield, M. C.
2017-12-01
The Alaska Center for Unmanned Aircraft Systems Integration (ACUASI) has developed a comprehensive program that incorporates pilots, flight/mission planners, geoscientists, university undergraduate and graduate students, and engineers together as one. We lead and support unmanned aircraft system (UAS) missions for geoscience research, emergency response, humanitarian needs, engineering design, and policy development. We are the University of Alaska's UAS research program, lead the Federal Aviation Administration (FAA) Pan-Pacific UAS Test Range Complex (PPUTRC) with Hawaii, Oregon, and Mississippi and in 2015 became a core member of the FAA Center of Excellence for UAS Research, managed by Mississippi State University. ACUASI's suite of aircraft include small hand-launched/vertical take-off and landing assets for short-term rapid deployment to large fixed-wing gas powered systems that provide multiple hours of flight time. We have extensive experience in Arctic and sub-Arctic environments and will present on how we have used our aircraft and payloads in numerous missions that include beyond visual line of sight flights, mapping the river ice-hazard in Alaska during spring break-up, and providing UAS-based observations for local Alaskans to navigate through the changing ice shelf of Northern Alaska. Several sensor developments of interest in the near future include building payloads for thermal infrared mapping at high spatial resolutions, combining forward and nadir looking cameras on the same UAS aircraft for topographic mapping, and using neutral density and narrow band filters to map very high temperature thermally active hazards, such as forest fires and volcanic eruptions. The ACUASI team working together provide us the experience, tools, capabilities, and personnel to build and maintain a world class research center for unmanned aircraft systems as well as support both real-time operations and geoscience research.
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Study of advanced fuel system concepts for commercial aircraft
Coffinberry, G. A.
1985-01-01
An analytical study was performed in order to assess relative performance and economic factors involved with alternative advanced fuel systems for future commercial aircraft operating with broadened property fuels. The DC-10-30 wide-body tri-jet aircraft and the CF6-8OX engine were used as a baseline design for the study. Three advanced systems were considered and were specifically aimed at addressing freezing point, thermal stability and lubricity fuel properties. Actual DC-10-30 routes and flight profiles were simulated by computer modeling and resulted in prediction of aircraft and engine fuel system temperatures during a nominal flight and during statistical one-day-per-year cold and hot flights. Emergency conditions were also evaluated. Fuel consumption and weight and power extraction results were obtained. An economic analysis was performed for new aircraft and systems. Advanced system means for fuel tank heating included fuel recirculation loops using engine lube heat and generator heat. Environmental control system bleed air heat was used for tank heating in a water recirculation loop. The results showed that fundamentally all of the three advanced systems are feasible but vary in their degree of compatibility with broadened-property fuel.
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Sellers, William L., III; Dwoyer, Douglas L.
1992-01-01
The design of a hypersonic aircraft poses unique challenges to the engineering community. Problems with duplicating flight conditions in ground based facilities have made performance predictions risky. Computational fluid dynamics (CFD) has been proposed as an additional means of providing design data. At the present time, CFD codes are being validated based on sparse experimental data and then used to predict performance at flight conditions with generally unknown levels of uncertainty. This paper will discuss the facility and measurement techniques that are required to support CFD development for the design of hypersonic aircraft. Illustrations are given of recent success in combining experimental and direct numerical simulation in CFD model development and validation for hypersonic perfect gas flows.
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Wind Information Uplink to Aircraft Performing Interval Management Operations
Ahmad, Nashat N.; Barmore, Bryan E.; Swieringa, Kurt A.
2016-01-01
Interval Management (IM) is an ADS-B-enabled suite of applications that use ground and flight deck capabilities and procedures designed to support the relative spacing of aircraft (Barmore et al., 2004, Murdoch et al. 2009, Barmore 2009, Swieringa et al. 2011; Weitz et al. 2012). Relative spacing refers to managing the position of one aircraft to a time or distance relative to another aircraft, as opposed to a static reference point such as a point over the ground or clock time. This results in improved inter-aircraft spacing precision and is expected to allow aircraft to be spaced closer to the applicable separation standard than current operations. Consequently, if the reduced spacing is used in scheduling, IM can reduce the time interval between the first and last aircraft in an overall arrival flow, resulting in increased throughput. Because IM relies on speed changes to achieve precise spacing, it can reduce costly, low-altitude, vectoring, which increases both efficiency and throughput in capacity-constrained airspace without negatively impacting controller workload and task complexity. This is expected to increase overall system efficiency. The Flight Deck Interval Management (FIM) equipment provides speeds to the flight crew that will deliver them to the achieve-by point at the controller-specified time, i.e., assigned spacing goal, after the target aircraft crosses the achieve-by point (Figure 1.1). Since the IM and target aircraft may not be on the same arrival procedure, the FIM equipment predicts the estimated times of arrival (ETA) for both the IM and target aircraft to the achieve-by point. This involves generating an approximate four-dimensional trajectory for each aircraft. The accuracy of the wind data used to generate those trajectories is critical to the success of the IM operation. There are two main forms of uncertainty in the wind information used by the FIM equipment. The first is the accuracy of the forecast modeling done by the weather
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Structural Integrity Assessment of Reactor Containment Subjected to Aircraft Crash
International Nuclear Information System (INIS)
Kim, Junyong; Chang, Yoonsuk
2013-01-01
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
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Pak, Chan-Gi
2013-01-01
Modern aircraft employ a significant fraction of their weight in composite materials to reduce weight and improve performance. Aircraft aeroservoelastic models are typically characterized by significant levels of model parameter uncertainty due to the composite manufacturing process. Small modeling errors in the finite element model will eventually induce errors in the structural flexibility and mass, thus propagating into unpredictable errors in the unsteady aerodynamics and the control law design. One of the primary objectives of Multi Utility Technology Test-bed (MUTT) aircraft is the flight demonstration of active flutter suppression, and therefore in this study, the identification of the primary and secondary modes for the structural model tuning based on the flutter analysis of MUTT aircraft. The ground vibration test-validated structural dynamic finite element model of the MUTT aircraft is created in this study. The structural dynamic finite element model of MUTT aircraft is improved using the in-house Multi-disciplinary Design, Analysis, and Optimization tool. In this study, two different weight configurations of MUTT aircraft have been improved simultaneously in a single model tuning procedure.
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CSIR Research Space (South Africa)
Burger, CR
2011-09-01
Full Text Available - unmanned aircraft; pilot training. I. INTRODUCTION Unmanned aircraft offer flexibility not found in manned aircraft. They can be made smaller and cheaper to operate. They offer payload advantages relative to small manned aircraft. They can also perform... certificate to non-state users. To facilitate useful operations by UAs, future operations must be subject to no more than routine notification (e.g. an ATC flight plan), just like manned aircraft already are. Before such operations can be established, some...
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Maneuvering control and configuration adaptation of a biologically inspired morphing aircraft
Abdulrahim, Mujahid
Natural flight as a source of inspiration for aircraft design was prominent with early aircraft but became marginalized as aircraft became larger and faster. With recent interest in small unmanned air vehicles, biological inspiration is a possible technology to enhance mission performance of aircraft that are dimensionally similar to gliding birds. Serial wing joints, loosely modeling the avian skeletal structure, are used in the current study to allow significant reconfiguration of the wing shape. The wings are reconfigured to optimize aerodynamic performance and maneuvering metrics related to specific mission tasks. Wing shapes for each mission are determined and related to the seagulls, falcons, albatrosses, and non-migratory African swallows on which the aircraft are based. Variable wing geometry changes the vehicle dynamics, affording versatility in flight behavior but also requiring appropriate compensation to maintain stability and controllability. Time-varying compensation is in the form of a baseline controller which adapts to both the variable vehicle dynamics and to the changing mission requirements. Wing shape is adapted in flight to minimize a cost function which represents energy, temporal, and spatial efficiency. An optimal control architecture unifies the control and adaptation tasks.
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Directory of Open Access Journals (Sweden)
Vadim V. Efimov
2018-01-01
Full Text Available Functional properties characterize the purpose of the aircraft and are described by its flight performance characteristics such as range and cruising speed, payload, runway characteristics, etc. Functional properties also characterize the aircraft efficiency that determines the objective need for their analysis by both aircraft designers and operators in conditions of permanent and systematic efficiency increase necessity. When choosing the aircraft, it is important for the operator to make sure that a selected aircraft type has a high level of functional properties, which will allow it to provide high operational efficiency without obsolescence in the long term. However, when choosing from several aircraft types the operator has to face the fact that some characteristics of considered aircraft variants are better and the others are worse that does not allow to definitely determine what aircraft type has a higher level of functional properties.The possibility of applying technical efficiency indicators and a generalized technical level indicator for analyzing the functional properties of civil aviation aircraft is explored in this article. Fuel, weight and target efficiency values as well as the previously improved technical level indicator value were calculated for the different generations and modifications of Boeing 737 and Airbus A320 families of medium-range airplanes, which was followed by the results interpretation within one airplane generation and when moving historically from one airplane generation to another. According to analysis results it is concluded that it is impossible to define the change of the aircraft functional properties level by the change in the values of separate technical efficiency indicators. Thus, it is proposed to use a generalized technical level indicator that determines the level of aircraft technical perfection for purpose and to use efficiency indicators to analyze the cost of providing this level of
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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
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40 CFR 87.6 - Aircraft safety.
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. ...
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Assessing effects of military aircraft noise on residential property values near airbases
Fidell, Sanford; Tabachnick, Barbara; Silvati, Laura; Cook, Brenda
The question, 'Does military aircraft noise exposure affect residential property values in the vicinity of Air Force bases?', can be asked and answered with varying degrees of generality and tolerable errors of inference. Definitive answers are difficult to develop because the question itself may not be meaningful in some circumstances: property values are affected by many factors other than aircraft noise which can fluctuate greatly in different areas and during different time periods; credible attribution of causality for changes in property values uniquely to aircraft noise requires many costly study design measures; and prior findings suggest that if a relationship exists, it is not a large or especially strong one. Thus, evidence of a simple geographic association between aircraft noise exposure and residential property values does not provide a conclusive answer to the question. In an effort to develop more compelling evidence, the US Air Force is planning to compare historical records of sale prices of properties in areas of differential aircraft noise exposure during specific time periods with predictions of sale prices derived from a validated statistical model of residential property values.
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Smith, P. J.; Thomson, L. W.; Wilson, R. D.
1986-01-01
NASA sponsored composites research and development programs were set in place to develop the critical engineering technologies in large transport aircraft structures. This NASA-Boeing program focused on the critical issues of damage tolerance and pressure containment generic to the fuselage structure of large pressurized aircraft. Skin-stringer and honeycomb sandwich composite fuselage shell designs were evaluated to resolve these issues. Analyses were developed to model the structural response of the fuselage shell designs, and a development test program evaluated the selected design configurations to appropriate load conditions.
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Flight test results for the Daedalus and Light Eagle human powered aircraft
Sullivan, R. Bryan; Zerweckh, Siegfried H.
1988-01-01
The results of the flight test program of the Daedalus and Light Eagle human powered aircraft in the winter of 1987/88 are given. The results from experiments exploring the Light Eagle's rigid body and structural dynamics are presented. The interactions of these dynamics with the autopilot design are investigated. Estimates of the power required to fly the Daedalus aircraft are detailed. The system of sensors, signal conditioning boards, and data acquisition equipment used to record the flight data is also described. In order to investigate the dynamics of the aircraft, flight test maneuvers were developed to yield maximum data quality from the point of view of estimating lateral and longitudinal stability derivatives. From this data, structural flexibility and unsteady aerodynamics have been modeled in an ad hoc manner and are used to augment the equations of motion with flexibility effects. Results of maneuvers that were flown are compared with the predictions from the flexibility model. To extend the ad hoc flexibility model, a fully flexible aeroelastic model has been developed. The model is unusual in the approximate equality of many structural natural frequencies and the importance of unsteady aerodynamic effects. the Gossamer Albatross. It is hypothesized that this inverse ground effect is caused by turbulence in the Earth's boundary layer. The diameters of the largest boundary layer eddies (which represent most of the turbulent kinetic energy) are proportional to altitude; thus, closer to the ground, the energy in the boundary layer becomes concentrated in eddies of smaller and smaller diameter. Eventually the eddies become sufficiently small (approximately 0.5 cm) that they trip the laminar boundary layer on the wing. As a result, a greater percentage of the wing area is covered with turbulent flow. Consequently the aircraft's drag and the pow er required both increase as the aircraft flies closer to the ground. The results of the flight test program are
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System for indicating fuel-efficient aircraft altitude
Gary, B. L. (Inventor)
1984-01-01
A method and apparatus are provided for indicating the altitude at which an aircraft should fly so the W/d ratio (weight of the aircraft divided by the density of air) more closely approaches the optimum W/d for the aircraft. A passive microwave radiometer on the aircraft is directed at different angles with respect to the horizon to determine the air temperature, and therefore the density of the air, at different altitudes. The weight of the aircraft is known. The altitude of the aircraft is changed to fly the aircraft at an altitude at which is W/d ratio more closely approaches the optimum W/d ratio for that aircraft.
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Expert systems and their use in augmenting design optimization
Kidwell, G. H.; Eskey, M. A.
1985-01-01
The challenging requirements that are evolving for future aircraft demand that each design be optimally integrated, for the penalties imposed by nonoptimal performance are significant. Classic numerical optimization algorithms have been and will continue to be important tools for aircraft designers. These methods are, however, limited to certain categories of aircraft design variables, leaving the remainder to be determined by the user. A method that makes use of knowledge-based expert systems offers the potential for aiding the conceptual design process in a way that is similar to that of numerical optimization, except that it would address discrete, discontinuous, abstract, or any other unoptimized aspect of vehicle design and integration. Other unique capabilities such as automatic discovery and learning in design may also be achievable in the near term. This paper discusses current practice in conceptual aircraft design and knowledge-based systems, and how knowledge-based systems can be used in conceptual design.
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Participant Assessments of Aviation Safety Inspector Training for Technically Advanced Aircraft
National Research Council Canada - National Science Library
Chidester, Thomas; Hackworth, Carla; Knecht, William
2007-01-01
.... Currently, Federal Aviation Administration (FAA) aviation safety inspectors are required to inspect technically advanced aircraft, check certified flight instructors, and conduct surveillance of designated pilot examiners who are certifying pilots...
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The Second Joint NASA/FAA/DOD Conference on Aging Aircraft. Pt. 1
Harris, Charles E. (Editor)
1999-01-01
The purpose of the Conference was to bring together world leaders in aviation safety research, aircraft design and manufacturing, fleet operation and aviation maintenance to disseminate information on current practices and advanced technologies that will assure the continued airworthiness of the aging aircraft in the military and commercial fleets. The Conference included reviews of current industry practices, assessments of future technology requirements, and status of aviation safety research. The Conference provided an opportunity for interactions among the key personnel in the research and technology development community, the original equipment manufacturers, commercial airline operators, military fleet operators, aviation maintenance, and aircraft certification and regulatory authorities. Conference participation was unrestricted and open to the international aviation community.
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Flight mechanics of a tailless articulated wing aircraft
International Nuclear Information System (INIS)
Paranjape, Aditya A; Chung, Soon-Jo; Selig, Michael S
2011-01-01
This paper investigates the flight mechanics of a micro aerial vehicle without a vertical tail in an effort to reverse-engineer the agility of avian flight. The key to stability and control of such a tailless aircraft lies in the ability to control the incidence angles and dihedral angles of both wings independently. The dihedral angles can be varied symmetrically on both wings to control aircraft speed independently of the angle of attack and flight path angle, while asymmetric dihedral can be used to control yaw in the absence of a vertical stabilizer. It is shown that wing dihedral angles alone can effectively regulate sideslip during rapid turns and generate a wide range of equilibrium turn rates while maintaining a constant flight speed and regulating sideslip. Numerical continuation and bifurcation analysis are used to compute trim states and assess their stability. This paper lays the foundation for design and stability analysis of a flapping wing aircraft that can switch rapidly from flapping to gliding flight for agile manoeuvring in a constrained environment.
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Flight mechanics of a tailless articulated wing aircraft
Energy Technology Data Exchange (ETDEWEB)
Paranjape, Aditya A; Chung, Soon-Jo; Selig, Michael S, E-mail: sjchung@illinois.edu [Department of Aerospace Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States)
2011-06-15
This paper investigates the flight mechanics of a micro aerial vehicle without a vertical tail in an effort to reverse-engineer the agility of avian flight. The key to stability and control of such a tailless aircraft lies in the ability to control the incidence angles and dihedral angles of both wings independently. The dihedral angles can be varied symmetrically on both wings to control aircraft speed independently of the angle of attack and flight path angle, while asymmetric dihedral can be used to control yaw in the absence of a vertical stabilizer. It is shown that wing dihedral angles alone can effectively regulate sideslip during rapid turns and generate a wide range of equilibrium turn rates while maintaining a constant flight speed and regulating sideslip. Numerical continuation and bifurcation analysis are used to compute trim states and assess their stability. This paper lays the foundation for design and stability analysis of a flapping wing aircraft that can switch rapidly from flapping to gliding flight for agile manoeuvring in a constrained environment.
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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.)
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Configuration management and automatic control of an augmentor wing aircraft with vectored thrust
Cicolani, L. S.; Sridhar, B.; Meyer, G.
1979-01-01
An advanced structure for automatic flight control logic for powered-lift aircraft operating in terminal areas is under investigation at Ames Research Center. This structure is based on acceleration control; acceleration commands are constructed as the sum of acceleration on the reference trajectory and a corrective feedback acceleration to regulate path tracking errors. The central element of the structure, termed a Trimmap, uses a model of the aircraft aerodynamic and engine forces to calculate the control settings required to generate the acceleration commands. This report describes the design criteria for the Trimmap and derives a Trimmap for Ames experimental augmentor wing jet STOL research aircraft.
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SIMPLIFIED MATHEMATICAL MODEL OF SMALL SIZED UNMANNED AIRCRAFT VEHICLE LAYOUT
Directory of Open Access Journals (Sweden)
2016-01-01
Full Text Available Strong reduction of new aircraft design period using new technology based on artificial intelligence is the key problem mentioned in forecasts of leading aerospace industry research centers. This article covers the approach to devel- opment of quick aerodynamic design methods based on artificial intelligence neural system. The problem is being solved for the classical scheme of small sized unmanned aircraft vehicle (UAV. The principal parts of the method are the mathe- matical model of layout, layout generator of this type of aircraft is built on aircraft neural networks, automatic selection module for cleaning variety of layouts generated in automatic mode, robust direct computational fluid dynamics method, aerodynamic characteristics approximators on artificial neural networks.Methods based on artificial neural networks have intermediate position between computational fluid dynamics methods or experiments and simplified engineering approaches. The use of ANN for estimating aerodynamic characteris-tics put limitations on input data. For this task the layout must be presented as a vector with dimension not exceeding sev-eral hundred. Vector components must include all main parameters conventionally used for layouts description and com- pletely replicate the most important aerodynamics and structural properties.The first stage of the work is presented in the paper. Simplified mathematical model of small sized UAV was developed. To estimate the range of geometrical parameters of layouts the review of existing vehicle was done. The result of the work is the algorithm and computer software for generating the layouts based on ANN technolo-gy. 10000 samples were generated and the dataset containig geometrical and aerodynamic characteristics of layoutwas created.
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Bigelow, Catherine A. (Compiler)
1997-01-01
This publication contains the fifty-two technical papers presented at the FAA-NASA Symposium on the Continued Airworthiness of Aircraft Structures. The symposium, hosted by the FAA Center of Excellence for Computational Modeling of Aircraft Structures at Georgia Institute of Technology, was held to disseminate information on recent developments in advanced technologies to extend the life of high-time aircraft and design longer-life aircraft. Affiliations of the participants included 33% from government agencies and laboratories, 19% from academia, and 48% from industry; in all 240 people were in attendance. Technical papers were selected for presentation at the symposium, after a review of extended abstracts received by the Organizing Committee from a general call for papers.
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Bigelow, Catherine A. (Compiler)
1997-01-01
This publication contains the fifty-two technical papers presented at the FAA-NASA Symposium on the Continued Airworthiness of Aircraft Structures. The symposium, hosted by the FAA Center of Excellence for Computational Modeling of Aircraft Structures at Georgia Institute of Technology, was held to disseminate information on recent developments in advanced technologies to extend the life of high-time aircraft and design longer-life aircraft. Affiliations of the participants included 33% from government agencies and laboratories, 19% from academia, and 48% from industry; in all 240 people were in attendance. Technical papers were selected for presentation at the symposium, after a review of extended abstracts received by the Organizing Committee from a general call for papers.
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Fettered aircraft for using wind energy
Energy Technology Data Exchange (ETDEWEB)
Hoeppner, H.; Horvath, E.; Ulrich, S.
1980-08-28
The invention concerns an aircraft tethered by cables, whose balloon-shaped central body produces static and aerodynamic upthrust and which carries turbines, which are used to convert wind energy and to drive the aircraft. The purpose of the invention is to provide an aircraft, which will keep wind energy plant at the optimum height. A new type of aircraft is used to solve the problem, which, according to the invention, combines static upthrust, the production of aerodynamic upthrust, wind energy conversion, energy transport and forward drive in a technically integrated aircraft. If the use of windpower is interrupted, then if necessary the drive together with a remote control system provides controlled free flight of the aircraft. One variant of the object of the invention consists of a central, balloon-shaped body for upthrust, in which there are wind turbines driving electrical generators. According to the invention the motors required to start the wind turbines are of such dimensions that they will drive the turbines in free flight of the aircraft and thus provide forward drive of the aircraft. A power generating unit, consisting of an internal combustion engine and the starter motors switched over to generator operation is used to provide house service supplies for control and regulation of the aircraft.
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International Nuclear Information System (INIS)
Zilio, Claudio; Patricelli, Luca
2014-01-01
The anti-ice systems are critical for airplane safety, but are also strongly affecting the fuel consumption of the aircraft. A complete model of this system allows the designers to investigate all possible combination of external parameters and improve the design of current anti-ice systems. The dynamic model of an anti-ice system is presented and the results of the model are validated thanks to a series of experimental tests. The model has been used to analyze the behavior of an anti-ice system at extreme high bleed air temperature which are typical of new generation aircraft engines. An innovative architecture for anti-ice system is studied and the benefits on aircraft fuel consumption for a standard day mission are shown. -- Highlights: • A detailed mathematical model of an anti-ice valves has been created. • Experimental results confirm the goodness of the developed model. • Instability of the valves has been studied. • A new architecture for the anti-ice systems is proposed and the impacts on the aircraft fuel consumption are analyzed
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Energy Technology Data Exchange (ETDEWEB)
Jordan, W. H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Cramer, S. J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Miller, A. J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
1957-03-12
This quarterly progress report of the Aircraft Nuclear Propulsion Project at ORNL records the technical progress of the research on circulating-fuel reactors and other ANP research at the Laboratory under its Contract W-7405-eng-26. The report is divided into five major parts: 1. Aircraft Reactor Engineering, 2. Chemistry, 3. Metallurgy, 4. Heat Transfer and Physical Properties, Radiation Damage, and Fuel Recovery and Reprocessing, and 5. Reactor Shielding. The ANP Project is comprised of about 550 technical and scientific personnel engaged in many phases of research directed toward the achievement of nuclear propulsion of aircraft. A considerable portion of this research is performed in support of the work of other organizations participating in the national ANP effort. However, the bulk of the ANP research at ORNL is directed toward the development of a circulating-fuel type of reactor. The design, construction, and operation of the Aircraft Reactor Test (ART), with the cooperation of the Pratt & Whitney Aircraft Division, are the current objectives of the project. The ART is to be a power plant system that will include a 60-Mw circulating fuel reflector-moderator reactor and adequate means for heat disposal. Operation of the system will be for the purpose of determining feasibility and for studying the problems associated with the design, construction, and operation of a high-power circulating-fuel refIector-moderated aircraft reactor system.
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Hanson, Curt; Schaefer, Jacob; Burken, John J.; Larson, David; Johnson, Marcus
2014-01-01
Flight research has shown the effectiveness of adaptive flight controls for improving aircraft safety and performance in the presence of uncertainties. The National Aeronautics and Space Administration's (NASA)'s Integrated Resilient Aircraft Control (IRAC) project designed and conducted a series of flight experiments to study the impact of variations in adaptive controller design complexity on performance and handling qualities. A novel complexity metric was devised to compare the degrees of simplicity achieved in three variations of a model reference adaptive controller (MRAC) for NASA's F-18 (McDonnell Douglas, now The Boeing Company, Chicago, Illinois) Full-Scale Advanced Systems Testbed (Gen-2A) aircraft. The complexity measures of these controllers are also compared to that of an earlier MRAC design for NASA's Intelligent Flight Control System (IFCS) project and flown on a highly modified F-15 aircraft (McDonnell Douglas, now The Boeing Company, Chicago, Illinois). Pilot comments during the IRAC research flights pointed to the importance of workload on handling qualities ratings for failure and damage scenarios. Modifications to existing pilot aggressiveness and duty cycle metrics are presented and applied to the IRAC controllers. Finally, while adaptive controllers may alleviate the effects of failures or damage on an aircraft's handling qualities, they also have the potential to introduce annoying changes to the flight dynamics or to the operation of aircraft systems. A nuisance rating scale is presented for the categorization of nuisance side-effects of adaptive controllers.
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In-flight Fault Detection and Isolation in Aircraft Flight Control Systems
Azam, Mohammad; Pattipati, Krishna; Allanach, Jeffrey; Poll, Scott; Patterson-Hine, Ann
2005-01-01
In this paper we consider the problem of test design for real-time fault detection and isolation (FDI) in the flight control system of fixed-wing aircraft. We focus on the faults that are manifested in the control surface elements (e.g., aileron, elevator, rudder and stabilizer) of an aircraft. For demonstration purposes, we restrict our focus on the faults belonging to nine basic fault classes. The diagnostic tests are performed on the features extracted from fifty monitored system parameters. The proposed tests are able to uniquely isolate each of the faults at almost all severity levels. A neural network-based flight control simulator, FLTZ(Registered TradeMark), is used for the simulation of various faults in fixed-wing aircraft flight control systems for the purpose of FDI.
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Bayesian Software Health Management for Aircraft Guidance, Navigation, and Control
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.
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Aircraft Capability Management
Mumaw, Randy; Feary, Mike
2018-01-01
This presentation presents an overview of work performed at NASA Ames Research Center in 2017. The work concerns the analysis of current aircraft system management displays, and the initial development of an interface for providing information about aircraft system status. The new interface proposes a shift away from current aircraft system alerting interfaces that report the status of physical components, and towards displaying the implications of degradations on mission capability. The proposed interface describes these component failures in terms of operational consequences of aircraft system degradations. The research activity was an effort to examine the utility of different representations of complex systems and operating environments to support real-time decision making of off-nominal situations. A specific focus was to develop representations that provide better integrated information to allow pilots to more easily reason about the operational consequences of the off-nominal situations. The work is also seen as a pathway to autonomy, as information is integrated and understood in a form that automated responses could be developed for the off-nominal situations in the future.
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Design of LPV-Based Sliding Mode Controller with Finite Time Convergence for a Morphing Aircraft
Directory of Open Access Journals (Sweden)
Nuan Wen
2017-01-01
Full Text Available This paper proposes a finite time convergence sliding mode control (FSMC strategy based on linear parameter-varying (LPV methodology for the stability control of a morphing aircraft subject to parameter uncertainties and external disturbances. Based on the Kane method, a longitudinal dynamic model of the morphing aircraft is built. Furthermore, the linearized LPV model of the aircraft in the wing transition process is obtained, whose scheduling parameters are wing sweep angle and wingspan. The FSMC scheme is developed into LPV systems by applying the previous results for linear time-invariant (LTI systems. The sufficient condition in form of linear matrix inequality (LMI constraints is derived for the existence of a reduced-order sliding mode, in which the dynamics can be ensured to keep robust stability and L2 gain performance. The tensor-product (TP model transformation approach can be directly applied to solve infinite LMIs belonging to the polynomial parameter-dependent LPV system. Then, by the parameter-dependent Lyapunov function stability analysis, the synthesized FSMC is proved to drive the LPV system trajectories toward the predefined switching surface with a finite time arrival. Comparative simulation results in the nonlinear model demonstrate the robustness and effectiveness of this approach.
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Utilizing High Fidelity Simulations in Multidisciplinary Optimization of Aircraft Systems, Phase I
National Aeronautics and Space Administration — Aircraft design is a complex process requiring interactions and exchange of information among multiple disciplines such as aerodynamics, strength, fatigue, controls,...
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Directory of Open Access Journals (Sweden)
C. Priyant Mark
2016-06-01
Full Text Available The design of an annular combustion chamber in a gas turbine engine is the backbone of this paper. It is specifically designed for a low bypass turbofan engine in a jet trainer aircraft. The combustion chamber is positioned in between the compressor and turbine. It has to be designed based on the constant pressure, enthalpy addition process. The present methodology deals with the computation of the initial design parameters from benchmarking of real-time industry standards and arriving at optimized values. It is then studied for feasibility and finalized. Then the various dimensions of the combustor are calculated based on different empirical formulas. The air mass flow is then distributed across the zones of the combustor. The cooling requirement is met using the cooling holes. Finally the variations of parameters at different points are calculated. The whole combustion chamber is modeled using Siemens NX 8.0, a modeling software and presented. The model is then analyzed using various parameters at various stages and levels to determine the optimized design. The aerodynamic flow characteristics is simulated numerically by means of ANSYS 14.5 software suite. The air-fuel mixture, combustion-turbulence, thermal and cooling analysis is carried out. The analysis is performed at various scenarios and compared. The results are then presented in image outputs and graphs.
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Personal Aircraft Point to the Future of Transportation
2010-01-01
NASA's Small Business Innovation Research (SBIR) and Small Business Technology Transfer (STTR) programs, as well as a number of Agency innovations, have helped Duluth, Minnesota-based Cirrus Design Corporation become one of the world's leading manufacturers of general aviation aircraft. SBIRs with Langley Research Center provided the company with cost-effective composite airframe manufacturing methods, while crashworthiness testing at the Center increased the safety of its airplanes. Other NASA-derived technologies on Cirrus SR20 and SR22 aircraft include synthetic vision systems that help pilots navigate and full-plane parachutes that have saved the lives of more than 30 Cirrus pilots and passengers to date. Today, the SR22 is the world's top-selling Federal Aviation Administration (FAA)-certified single-engine airplane.
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Advanced composite elevator for Boeing 727 aircraft. Volume 1: Technical summary
Chovil, D. V.; Harvey, S. T.; Mccarty, J. E.; Desper, O. E.; Jamison, E. S.; Syder, H.
1981-01-01
The design, development, analysis, and testing activities and results that were required to produce five and one-half shipsets of advanced composite elevators for Boeing 727 aircraft are summarized. During the preliminary design period, alternative concepts were developed. After selection of the best design, detail design and basic configuration improvements were evaluated. Five and one-half shipsets were manufactured. All program goals (except competitive cost demonstration) were accomplished when our design met or exceeded all requirements, criteria, and objectives.
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Low Energy Nuclear Reaction Aircraft- 2013 ARMD Seedling Fund Phase I Project
Wells, Douglas P.; McDonald, Robert; Campbell, Robbie; Chase, Adam; Daniel, Jason; Darling, Michael; Green, Clayton; MacGregor, Collin; Sudak, Peter; Sykes, Harrison;
2014-01-01
This report serves as the final written documentation for the Aeronautic Research Mission Directorate (ARMD) Seedling Fund's Low Energy Nuclear Reaction (LENR) Aircraft Phase I project. The findings presented include propulsion system concepts, synergistic missions, and aircraft concepts. LENR is a form of nuclear energy that potentially has over 4,000 times the energy density of chemical energy sources. It is not expected to have any harmful emissions or radiation which makes it extremely appealing. There is a lot of interest in LENR, but there are no proven theories. This report does not explore the feasibility of LENR. Instead, it assumes that a working system is available. A design space exploration shows that LENR can enable long range and high speed missions. Six propulsion concepts, six missions, and four aircraft concepts are presented. This report also includes discussion of several issues and concerns that were uncovered during the study and potential research areas to infuse LENR aircraft into NASA's aeronautics research.
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Topology Optimization of an Aircraft Wing
2015-06-11
which selected as the most prevalent independent structure in the wing. The tank location and shape was interpreted from the high material volume...Engineering Inc., 1820 E. Big Beaver Rd, Troy, MI 48083, Optistruct 12.0 User’s Guide, 2013. 126 10. T. Megson and H. Gordon, Aircraft structures for...software enhances the design of transportation,” Forbes Online, 2013. 13. Altair Engineering Inc., 1820 E. Big Beaver Rd, Troy, MI 48083, Hypermesh
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Advanced aircraft service life monitoring method via flight-by-flight load spectra
Lee, Hongchul
This research is an effort to understand current method and to propose an advanced method for Damage Tolerance Analysis (DTA) for the purpose of monitoring the aircraft service life. As one of tasks in the DTA, the current indirect Individual Aircraft Tracking (IAT) method for the F-16C/D Block 32 does not properly represent changes in flight usage severity affecting structural fatigue life. Therefore, an advanced aircraft service life monitoring method based on flight-by-flight load spectra is proposed and recommended for IAT program to track consumed fatigue life as an alternative to the current method which is based on the crack severity index (CSI) value. Damage Tolerance is one of aircraft design philosophies to ensure that aging aircrafts satisfy structural reliability in terms of fatigue failures throughout their service periods. IAT program, one of the most important tasks of DTA, is able to track potential structural crack growth at critical areas in the major airframe structural components of individual aircraft. The F-16C/D aircraft is equipped with a flight data recorder to monitor flight usage and provide the data to support structural load analysis. However, limited memory of flight data recorder allows user to monitor individual aircraft fatigue usage in terms of only the vertical inertia (NzW) data for calculating Crack Severity Index (CSI) value which defines the relative maneuver severity. Current IAT method for the F-16C/D Block 32 based on CSI value calculated from NzW is shown to be not accurate enough to monitor individual aircraft fatigue usage due to several problems. The proposed advanced aircraft service life monitoring method based on flight-by-flight load spectra is recommended as an improved method for the F-16C/D Block 32 aircraft. Flight-by-flight load spectra was generated from downloaded Crash Survival Flight Data Recorder (CSFDR) data by calculating loads for each time hack in selected flight data utilizing loads equations. From
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Analysis of Hybrid-Electric Propulsion System Designs for Small Unmanned Aircraft Systems
2010-03-01
small EM to provide extra power during acceleration and recharge during deceleration through regenerative braking . Power assist systems are similar...climbing (Fig. 4).18 Like automotive hybrids, the aircraft utilizes a form of regenerative braking by charging its battery pack through propeller...desirable.”5 The inherent risks of all three ISR mission categories lead towards small UAS being the best option in many cases to meet the military’s
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Dynamic ASE Modeling and Optimization of Aircraft with SpaRibs, Phase II
National Aeronautics and Space Administration — In aircraft design, reducing structural weight is often a prime objective, while various constraints in multiple disciplines, such as structure, aerodynamics and...
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Titanium fasteners. [for aircraft industry
Phillips, J. L.
1972-01-01
Titanium fasteners are used in large quantities throughout the aircraft industry. Most of this usage is in aluminum structure; where titanium structure exists, titanium fasteners are logically used as well. Titanium fasteners offer potential weight savings to the designer at a cost of approximately $30 per pound of weight saved. Proper and least cost usage must take into consideration type of fastener per application, galvanic couples and installation characteristics of protective coatings, cosmetic appearance, paint adhesion, installation forces and methods available and fatigue performance required.
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A novel integrated self-powered brake system for more electric aircraft
Directory of Open Access Journals (Sweden)
Yaoxing SHANG
2018-05-01
Full Text Available Traditional hydraulic brake systems require a complex system of pipelines between an aircraft engine driven pump (EDP and brake actuators, which increases the weight of the aircraft and may even cause serious vibration and leakage problems. In order to improve the reliability and safety of more electric aircraft (MEA, this paper proposes a new integrated self-powered brake system (ISBS for MEA. It uses a hydraulic pump geared to the main wheel to recover a small part of the kinetic energy of a landing aircraft. The recovered energy then serves as the hydraulic power supply for brake actuators. It does not require additional hydraulic source, thus removing the pipelines between an EDP and brake actuators. In addition, its self-powered characteristic makes it possible to brake as usual even in an emergency situation when the airborne power is lost. This paper introduces the working principle of the ISBS and presents a prototype. The mathematical models of a taxiing aircraft and the ISBS are established. A feedback linearization control algorithm is designed to fulfill the anti-skid control. Simulations are carried out to verify the feasibility of the ISBS, and experiments are conducted on a ground inertia brake test bench. The ISBS presents a good performance and provides a new potential solution in the field of brake systems for MEA. Keywords: Hydraulic, Feedback linearization control, More electric aircraft, Novel brake system, Self-powered
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International Nuclear Information System (INIS)
Jun Mizuno; Norihide Koshika; Eiichi Tanaka; Atsushi Suzuki; Yoshinori Mihara; Isao Nishimura
2005-01-01
Steel plate reinforced concrete (SC) walls and slabs are structural members in which the rebars of reinforced concrete are replaced by steel plates. Steel plate reinforced concrete structures are more attractive structural design alternatives to reinforced concrete structures, especially with thick, heavily reinforced walls and slabs such as nuclear structures, because they enable a much shorter construction period, greater earthquake resistant and more cost effectiveness. Experimental and analytical studies performed by the authors have also shown that SC structures are much more effective in mitigating damage against scaled aircraft models , as described in Parts 1 and 2 of this study. The objective of Part 3 was to determine the protective capability of SC walls and roofs against a full-scale aircraft impact by conducting numerical experiments to investigate the fracture behaviors and limit thicknesses of SC panels and to examine the effectiveness of SC panels in detail under design conditions. Furthermore, a simplified method is proposed for evaluating the localized damage induced by a full-scale engine impact. (authors)
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76 FR 57008 - Smoking of Electronic Cigarettes on Aircraft
2011-09-15
... not limited to: Electronic cigars, pipes, and devices designed to look like everyday products such as...] RIN 2105-AE06 Smoking of Electronic Cigarettes on Aircraft AGENCY: Office of the Secretary (OST... Transportation is proposing to amend its existing airline smoking rule to explicitly ban the use of electronic...
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Analysis of impact of large commercial aircraft on a prestressed containment building
International Nuclear Information System (INIS)
Lee, Kyoungsoo; Han, Sang Eul; Hong, Jung-Wuk
2013-01-01
Highlights: • Aircraft impact analyses are performed using the missile–target interaction method. • A large commercial B747 aircraft is considered with erosion effect. • The rigid wall impact test shows the validity of the developed aircraft model. • The parametric studies on the fictitious containment building are performed. • The plastic failure of the target is governed by the impulse of aircraft at the first momentum peak. - Abstract: In this paper, the results of nonlinear dynamic analyses of a concrete containment building under extreme loads are presented. The impact of a large commercial B747 airliner is investigated as the extreme load, and a rigid wall impact test is performed using commercial nonlinear finite element codes. The impact forces exerted by the aircraft are verified compared with the time-dependent impact force provided by OECD/NEA (2002), which was calculated based on the so-called Riera method. The rigid wall impact analysis shows that the finite element model of a B747 is appropriate for the purpose of the aircraft crash analysis exposed to the external hazard of “Beyond Design-Basis Events” defined by U.S. Nuclear Regulatory Commission. Finally, the applicability of this methodology is further studied and verified by conducting parametric studies on the critical infrastructures of nuclear power plant containment structures
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Analysis of impact of large commercial aircraft on a prestressed containment building
Energy Technology Data Exchange (ETDEWEB)
Lee, Kyoungsoo, E-mail: kylee@pvamu.edu [Center for Energy and Environmental Sustainability, Prairie View A and M University, Prairie view, TX, 77446 (United States); Han, Sang Eul, E-mail: hsang@inha.ac.kr [Department of Architectural Engineering, School of Architecture, Inha University, 253 Yonghyundong Nam-gu, Incheon, 402-751 (Korea, Republic of); Hong, Jung-Wuk, E-mail: j.hong@kaist.ac.kr [Department of Civil and Environmental Engineering, KAIST, 373-1 Guseon-dong, Yuseong-gu, Daejeon, 305-701 (Korea, Republic of)
2013-12-15
Highlights: • Aircraft impact analyses are performed using the missile–target interaction method. • A large commercial B747 aircraft is considered with erosion effect. • The rigid wall impact test shows the validity of the developed aircraft model. • The parametric studies on the fictitious containment building are performed. • The plastic failure of the target is governed by the impulse of aircraft at the first momentum peak. - Abstract: In this paper, the results of nonlinear dynamic analyses of a concrete containment building under extreme loads are presented. The impact of a large commercial B747 airliner is investigated as the extreme load, and a rigid wall impact test is performed using commercial nonlinear finite element codes. The impact forces exerted by the aircraft are verified compared with the time-dependent impact force provided by OECD/NEA (2002), which was calculated based on the so-called Riera method. The rigid wall impact analysis shows that the finite element model of a B747 is appropriate for the purpose of the aircraft crash analysis exposed to the external hazard of “Beyond Design-Basis Events” defined by U.S. Nuclear Regulatory Commission. Finally, the applicability of this methodology is further studied and verified by conducting parametric studies on the critical infrastructures of nuclear power plant containment structures.
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International Nuclear Information System (INIS)
Johansson, Cristina; Derelov, Micael; Olvander, Johan
2017-01-01
In order to help decision-makers in the early design phase to improve and make more cost-efficient system safety and reliability baselines of aircraft design concepts, a method (Multi-objective Optimization for Safety and Reliability Trade-off) that is able to handle trade-offs such as system safety, system reliability, and other characteristics, for instance weight and cost, is used. Multi-objective Optimization for Safety and Reliability Trade-off has been developed and implemented at SAAB Aeronautics. The aim of this paper is to demonstrate how the implemented method might work to aid the selection of optimal design alternatives. The method is a three-step method: step 1 involves the modelling of each considered target, step 2 is optimization, and step 3 is the visualization and selection of results (results processing). The analysis is performed within Architecture Design and Preliminary Design steps, according to the company's Product Development Process. The lessons learned regarding the use of the implemented trade-off method in the three cases are presented. The results are a handful of solutions, a basis to aid in the selection of a design alternative. While the implementation of the trade-off method is performed for companies, there is nothing to prevent adapting this method, with minimal modifications, for use in other industrial applications
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Energy Technology Data Exchange (ETDEWEB)
Johansson, Cristina [Mendeley, Broderna Ugglasgatan, Linkoping (Sweden); Derelov, Micael; Olvander, Johan [Linkoping University, IEI, Dept. of Machine Design, Linkoping (Sweden)
2017-03-15
In order to help decision-makers in the early design phase to improve and make more cost-efficient system safety and reliability baselines of aircraft design concepts, a method (Multi-objective Optimization for Safety and Reliability Trade-off) that is able to handle trade-offs such as system safety, system reliability, and other characteristics, for instance weight and cost, is used. Multi-objective Optimization for Safety and Reliability Trade-off has been developed and implemented at SAAB Aeronautics. The aim of this paper is to demonstrate how the implemented method might work to aid the selection of optimal design alternatives. The method is a three-step method: step 1 involves the modelling of each considered target, step 2 is optimization, and step 3 is the visualization and selection of results (results processing). The analysis is performed within Architecture Design and Preliminary Design steps, according to the company's Product Development Process. The lessons learned regarding the use of the implemented trade-off method in the three cases are presented. The results are a handful of solutions, a basis to aid in the selection of a design alternative. While the implementation of the trade-off method is performed for companies, there is nothing to prevent adapting this method, with minimal modifications, for use in other industrial applications.
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Optimizing height presentation for aircraft cockpit displays
Jordan, Chris S.; Croft, D.; Selcon, Stephen J.; Markin, H.; Jackson, M.
1997-02-01
This paper describes an experiment conducted to investigate the type of display symbology that most effectively conveys height information to users of head-down plan-view radar displays. The experiment also investigated the use of multiple information sources (redundancy) in the design of such displays. Subjects were presented with eight different height display formats. These formats were constructed from a control, and/or one, two, or three sources of redundant information. The three formats were letter coding, analogue scaling, and toggling (spatially switching the position of the height information from above to below the aircraft symbol). Subjects were required to indicate altitude awareness via a four-key, forced-choice keyboard response. Error scores and response times were taken as performance measures. There were three main findings. First, there was a significant performance advantage when the altitude information was presented above and below the symbol to aid the representation of height information. Second, the analogue scale, a line whose length indicated altitude, proved significantly detrimental to performance. Finally, no relationship was found between the number of redundant information sources employed and performance. The implications for future aircraft and displays are discussed in relation to current aircraft tactical displays and in the context of perceptual psychological theory.
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Rotor Systems Research Aircraft /RSRA/ canopy explosive severance/fracture
Bement, L. J.
1976-01-01
The Rotor Systems Research Aircraft (RSRA), a compound rotor/fixed-wing aircraft, incorporates an emergency escape system for the three crew members; to achieve unobstructed egress, the overhead acrylic canopies of each crew member will be explosively severed and fractured into predictably small, low-mass pieces. A canopy explosive severance/fracture system was developed under this investigation that included the following system design considerations: selection of canopy and explosive materials, determining the acrylic's explosive severance and fracture characteristics, evaluating the effects of installation variables and temperature, determining the most effective explosive patterns, conducting full-scale, flat and double-curvature canopy tests, and evaluating the effects of back-blast of the explosive into the cockpit.
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NDARC - NASA Design and Analysis of Rotorcraft
Johnson, Wayne
2015-01-01
The NASA Design and Analysis of Rotorcraft (NDARC) software is an aircraft system analysis tool that supports both conceptual design efforts and technology impact assessments. The principal tasks are to design (or size) a rotorcraft to meet specified requirements, including vertical takeoff and landing (VTOL) operation, and then analyze the performance of the aircraft for a set of conditions. For broad and lasting utility, it is important that the code have the capability to model general rotorcraft configurations, and estimate the performance and weights of advanced rotor concepts. The architecture of the NDARC code accommodates configuration flexibility, a hierarchy of models, and ultimately multidisciplinary design, analysis, and optimization. Initially the software is implemented with low-fidelity models, typically appropriate for the conceptual design environment. An NDARC job consists of one or more cases, each case optionally performing design and analysis tasks. The design task involves sizing the rotorcraft to satisfy specified design conditions and missions. The analysis tasks can include off-design mission performance calculation, flight performance calculation for point operating conditions, and generation of subsystem or component performance maps. For analysis tasks, the aircraft description can come from the sizing task, from a previous case or a previous NDARC job, or be independently generated (typically the description of an existing aircraft). The aircraft consists of a set of components, including fuselage, rotors, wings, tails, and propulsion. For each component, attributes such as performance, drag, and weight can be calculated; and the aircraft attributes are obtained from the sum of the component attributes. Description and analysis of conventional rotorcraft configurations is facilitated, while retaining the capability to model novel and advanced concepts. Specific rotorcraft configurations considered are single-main-rotor and tail
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NDARC NASA Design and Analysis of Rotorcraft
Johnson, Wayne R.
2009-01-01
The NASA Design and Analysis of Rotorcraft (NDARC) software is an aircraft system analysis tool intended to support both conceptual design efforts and technology impact assessments. The principal tasks are to design (or size) a rotorcraft to meet specified requirements, including vertical takeoff and landing (VTOL) operation, and then analyze the performance of the aircraft for a set of conditions. For broad and lasting utility, it is important that the code have the capability to model general rotorcraft configurations, and estimate the performance and weights of advanced rotor concepts. The architecture of the NDARC code accommodates configuration flexibility; a hierarchy of models; and ultimately multidisciplinary design, analysis, and optimization. Initially the software is implemented with lowfidelity models, typically appropriate for the conceptual design environment. An NDARC job consists of one or more cases, each case optionally performing design and analysis tasks. The design task involves sizing the rotorcraft to satisfy specified design conditions and missions. The analysis tasks can include off-design mission performance calculation, flight performance calculation for point operating conditions, and generation of subsystem or component performance maps. For analysis tasks, the aircraft description can come from the sizing task, from a previous case or a previous NDARC job, or be independently generated (typically the description of an existing aircraft). The aircraft consists of a set of components, including fuselage, rotors, wings, tails, and propulsion. For each component, attributes such as performance, drag, and weight can be calculated; and the aircraft attributes are obtained from the sum of the component attributes. Description and analysis of conventional rotorcraft configurations is facilitated, while retaining the capability to model novel and advanced concepts. Specific rotorcraft configurations considered are single main-rotor and
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Yamina BOUGHARI; Georges GHAZI; Ruxandra Mihaela BOTEZ; Florian THEEL
2017-01-01
Setting the appropriate controllers for aircraft stability and control augmentation systems are complicated and time consuming tasks. As in the Linear Quadratic Regulator method gains are found by selecting the appropriate weights or as in the Proportional Integrator Derivative control by tuning gains. A trial and error process is usually employed for the determination of weighting matrices, which is normally a time consuming procedure. Flight Control Law were optimized and designed by combin...
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2011-11-22
...; Special Conditions No. 23-253-SC] Special Conditions: Diamond Aircraft Industries, Model DA-40NG..., Model DA-40NG airplane. This airplane will have a novel or unusual design feature(s) associated with an... include the new model DA- 40NG with the Austro Engine GmbH model E4 Aircraft Diesel Engine (ADE). The...
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Hydrogen Storage for Aircraft Applications Overview
Colozza, Anthony J.; Kohout, Lisa (Technical Monitor)
2002-01-01
Advances in fuel cell technology have brought about their consideration as sources of power for aircraft. This power can be utilized to run aircraft systems or even provide propulsion power. One of the key obstacles to utilizing fuel cells on aircraft is the storage of hydrogen. An overview of the potential methods of hydrogen storage was compiled. This overview identifies various methods of hydrogen storage and points out their advantages and disadvantages relative to aircraft applications. Minimizing weight and volume are the key aspects to storing hydrogen within an aircraft. An analysis was performed to show how changes in certain parameters of a given storage system affect its mass and volume.
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Alexandrov, Natalia; Holmes, Bruce J.; Hahn, Andrew S.
2016-01-01
We report on an examination of potential benefits of infusing wireless technologies into various areas of aircraft and airspace operations. The analysis is done in support of a NASA seedling project Efficient Reconfigurable Cockpit Design and Fleet Operations Using Software Intensive, Network Enabled Wireless Architecture (ECON). The study has two objectives. First, we investigate one of the main benefit hypotheses of the ECON proposal: that the replacement of wired technologies with wireless would lead to significant weight reductions on an aircraft, among other benefits. Second, we advance a list of wireless technology applications and discuss their system benefits. With regard to the primary hypothesis, we conclude that the promise of weight reduction is premature. Specificity of the system domain and aircraft, criticality of components, reliability of wireless technologies, the weight of replacement or augmentation equipment, and the cost of infusion must all be taken into account among other considerations, to produce a reliable estimate of weight savings or increase.
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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.
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Capacity assessment of concrete containment vessels subjected to aircraft impact
Energy Technology Data Exchange (ETDEWEB)
Andonov, Anton, E-mail: anton.andonov@mottmac.com; Kostov, Marin; Iliev, Alexander
2015-12-15
Highlights: • An approach to assess the containment capacity to aircraft impact via fragility curves is proposed. • Momentum over Area was defined as most suitable reference parameter to describe the aircraft load. • The effect of the impact induced damages on the containment pressure capacity has been studied. • The studied containment shows no reduction of the pressure capacity for the investigated scenarios. • The effectiveness of innovative protective structure against aircraft impact has been evaluated. - Abstract: The paper describes the procedure and the results from the assessment of the vulnerability of a generic pre-stressed containment structure subjected to a large commercial aircraft impact. Impacts of Boeing 737, Boeing 767 and Boeing 747 have been considered. The containment vulnerability is expressed by fragility curves based on the results of a number of nonlinear dynamic analyses. Three reference parameters have been considered as impact intensity measure in the fragility curve definition: peak impact force (PIF), peak impact pressure (PIP) and Momentum over Area (MoA). Conclusions on the most suitable reference parameter as well on the vulnerability of such containment vessels are drawn. The influence of the aircraft impact induced damages on the containment ultimate pressure capacity is also assessed and some preliminary conclusions on this are drawn. The paper also addresses a conceptual design of a protective structure able to decrease the containment vulnerability and provide a preliminary assessment of the applicability of such concept.
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Capacity assessment of concrete containment vessels subjected to aircraft impact
International Nuclear Information System (INIS)
Andonov, Anton; Kostov, Marin; Iliev, Alexander
2015-01-01
Highlights: • An approach to assess the containment capacity to aircraft impact via fragility curves is proposed. • Momentum over Area was defined as most suitable reference parameter to describe the aircraft load. • The effect of the impact induced damages on the containment pressure capacity has been studied. • The studied containment shows no reduction of the pressure capacity for the investigated scenarios. • The effectiveness of innovative protective structure against aircraft impact has been evaluated. - Abstract: The paper describes the procedure and the results from the assessment of the vulnerability of a generic pre-stressed containment structure subjected to a large commercial aircraft impact. Impacts of Boeing 737, Boeing 767 and Boeing 747 have been considered. The containment vulnerability is expressed by fragility curves based on the results of a number of nonlinear dynamic analyses. Three reference parameters have been considered as impact intensity measure in the fragility curve definition: peak impact force (PIF), peak impact pressure (PIP) and Momentum over Area (MoA). Conclusions on the most suitable reference parameter as well on the vulnerability of such containment vessels are drawn. The influence of the aircraft impact induced damages on the containment ultimate pressure capacity is also assessed and some preliminary conclusions on this are drawn. The paper also addresses a conceptual design of a protective structure able to decrease the containment vulnerability and provide a preliminary assessment of the applicability of such concept.
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Estimation of nuclear power plant aircraft hazards
International Nuclear Information System (INIS)
Gottlieb, P.
1978-01-01
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
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Application of AI methods to aircraft guidance and control
Hueschen, Richard M.; Mcmanus, John W.
1988-01-01
A research program for integrating artificial intelligence (AI) techniques with tools and methods used for aircraft flight control system design, development, and implementation is discussed. The application of the AI methods for the development and implementation of the logic software which operates with the control mode panel (CMP) of an aircraft is presented. The CMP is the pilot control panel for the automatic flight control system of a commercial-type research aircraft of Langley Research Center's Advanced Transport Operating Systems (ATOPS) program. A mouse-driven color-display emulation of the CMP, which was developed with AI methods and used to test the AI software logic implementation, is discussed. The operation of the CMP was enhanced with the addition of a display which was quickly developed with AI methods. The display advises the pilot of conditions not satisfied when a mode does not arm or engage. The implementation of the CMP software logic has shown that the time required to develop, implement, and modify software systems can be significantly reduced with the use of the AI methods.
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Schweizer RU-38A Twin-Condor: covert surveillance aircraft
O'Toole, Michael J.; Schweizer, Paul H.
1997-11-01
The world order has changed and with it, governments are now faced with waging a new type of `ware.' Regional instability, drug trafficking, environmental issues, international terrorism, and illegal immigration are examples of escalating problems that cross international boundaries and threaten the security of nations. The first and most important element in coping with these illegal activities is the ability to detect and monitor events in a timely and secure fashion. Conventional means of gathering intelligence such as large airborne collection systems and satellites lack the flexibility, dwell times, and cost effectiveness to meet many of today's needs. There is a growing requirement for airborne platforms that can covertly perform surveillance missions during either day or night and in a cost effective manner. To meet this need, Schweizer Aircraft has recently developed the RU-38A twin-engine surveillance aircraft. This paper discusses the evolution and principle design concepts of this aircraft and how its unique performance enables the RU-38A to achieve new levels of surveillance capability.
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Application of high-brightness LEDs in aircraft position lights
Machi, Nicolo; Mangum, Scott; Singer, Jeffrey M.
2004-10-01
Solid state lighting devices have made their way into a number of niche markets and continue to make inroads into other markets as their price / performance ratios improve. One of these markets is aviation lighting. Although this paper will focus on the use of LEDs for aircraft position lights, much of the discussion is applicable to other installations on the interior and exterior of the aircraft. The color, light distribution and intensity levels for a position light are all closely regulated through Code of Federal Regulation (CFR; formerly Federal Aviation Regulation (FAR)) documents. These lighting requirements, along with harsh thermal and environmental requirements, drive the design. In this paper, we will look at these requirements and discuss what is required in order to use LEDs for this type of application. We will explore the optical, thermal and electrical issues associated with the use of LEDs for position lights and examine the specific case study of the Astreon forward position lights. Finally, we will discuss some of the challenges that we see with solid state lighting in current and future aircraft applications.
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Flight Research into Simple Adaptive Control on the NASA FAST Aircraft
Hanson, Curtis E.
2011-01-01
A series of simple adaptive controllers with varying levels of complexity were designed, implemented and flight tested on the NASA Full-Scale Advanced Systems Testbed (FAST) aircraft. Lessons learned from the development and flight testing are presented.
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Aircraft Carrier Exposure Testing of Aircraft Materials
National Research Council Canada - National Science Library
Lee, Eui
2004-01-01
.... Test and control specimens were affixed on exposure racks and installed on aircraft carriers to compare adhesive bonding primers for aluminum and to determine the static property behavior of various...
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A survey of autonomous vision-based See and Avoid for Unmanned Aircraft Systems
Mcfadyen, Aaron; Mejias, Luis
2016-01-01
This paper provides a comprehensive review of the vision-based See and Avoid problem for unmanned aircraft. The unique problem environment and associated constraints are detailed, followed by an in-depth analysis of visual sensing limitations. In light of such detection and estimation constraints, relevant human, aircraft and robot collision avoidance concepts are then compared from a decision and control perspective. Remarks on system evaluation and certification are also included to provide a holistic review approach. The intention of this work is to clarify common misconceptions, realistically bound feasible design expectations and offer new research directions. It is hoped that this paper will help us to unify design efforts across the aerospace and robotics communities.
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Turboelectric Distributed Propulsion Engine Cycle Analysis for Hybrid-Wing-Body Aircraft
Felder, James L.; Kim, Hyun Dae; Brown, Gerald V.
2009-01-01
Meeting NASA's N+3 goals requires a fundamental shift in approach to aircraft and engine design. Material and design improvements allow higher pressure and higher temperature core engines which improve the thermal efficiency. Propulsive efficiency, the other half of the overall efficiency equation, however, is largely determined by the fan pressure ratio (FPR). Lower FPR increases propulsive efficiency, but also dramatically reduces fan shaft speed through the combination of larger diameter fans and reduced fan tip speed limits. The result is that below an FPR of 1.5 the maximum fan shaft speed makes direct drive turbines problematic. However, it is the low pressure ratio fans that allow the improvement in propulsive efficiency which, along with improvements in thermal efficiency in the core, contributes strongly to meeting the N+3 goals for fuel burn reduction. The lower fan exhaust velocities resulting from lower FPRs are also key to meeting the aircraft noise goals. Adding a gear box to the standard turbofan engine allows acceptable turbine speeds to be maintained. However, development of a 50,000+ hp gearbox required by fans in a large twin engine transport aircraft presents an extreme technical challenge, therefore another approach is needed. This paper presents a propulsion system which transmits power from the turbine to the fan electrically rather than mechanically. Recent and anticipated advances in high temperature superconducting generators, motors, and power lines offer the possibility that such devices can be used to transmit turbine power in aircraft without an excessive weight penalty. Moving to such a power transmission system does more than provide better matching between fan and turbine shaft speeds. The relative ease with which electrical power can be distributed throughout the aircraft opens up numerous other possibilities for new aircraft and propulsion configurations and modes of operation. This paper discusses a number of these new
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Wensley, J. H.; Lamport, L.; Goldberg, J.; Green, M. W.; Levitt, K. N.; Melliar-Smith, P. M.; Shostak, R. E.; Weinstock, C. B.
1978-01-01
SIFT (Software Implemented Fault Tolerance) is an ultrareliable computer for critical aircraft control applications that achieves fault tolerance by the replication of tasks among processing units. The main processing units are off-the-shelf minicomputers, with standard microcomputers serving as the interface to the I/O system. Fault isolation is achieved by using a specially designed redundant bus system to interconnect the processing units. Error detection and analysis and system reconfiguration are performed by software. Iterative tasks are redundantly executed, and the results of each iteration are voted upon before being used. Thus, any single failure in a processing unit or bus can be tolerated with triplication of tasks, and subsequent failures can be tolerated after reconfiguration. Independent execution by separate processors means that the processors need only be loosely synchronized, and a novel fault-tolerant synchronization method is described.
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Identification of Aircraft Hazards
International Nuclear Information System (INIS)
K. Ashley
2006-01-01
Aircraft hazards were determined to be potentially applicable to a repository at Yucca Mountain in ''Monitored Geological Repository External Events Hazards Screening Analysis'' (BSC 2005 [DIRS 174235], Section 6.4.1). That determination was conservatively based upon limited knowledge of flight data in the area of concern and upon crash data for aircraft of the type flying near Yucca Mountain. The purpose of this report is to identify specific aircraft hazards that may be applicable to a monitored geologic repository (MGR) at Yucca Mountain, using NUREG-0800, ''Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants'' (NRC 1987 [DIRS 103124], Section 3.5.1.6), as guidance for the inclusion or exclusion of identified aircraft hazards. The intended use of this report is to provide inputs for further screening and analysis of identified aircraft hazards based upon the criteria that apply to Category 1 and Category 2 event sequence analyses as defined in 10 CFR 63.2 [DIRS 176544] (Section 4). The scope of this report includes the evaluation of military, private, and commercial use of airspace in the 100-mile regional setting of the repository at Yucca Mountain with the potential for reducing the regional setting to a more manageable size after consideration of applicable screening criteria (Section 7)
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Energy Technology Data Exchange (ETDEWEB)
Sambell, K.W.
1976-04-01
A conceptual design study is presented of 1,985 commercial tilt rotor STOL transports for a NASA 200 n. mi. (370 km) STOL Mission. A 100-passenger STOL Variant (Bell D313) of the Phase I VTOL Tilt Rotor Aircraft is defined. Aircraft characteristics are given; with the aircraft redesigned to meet 2,000-foot (610 m) field criteria, with emphasis on low fuel consumption and low direct operating cost. The 100-passenger STOL Tilt Rotor Aircraft was analyzed for performance, weights, economics, handling qualities, noise footprint and aeroelastic stability. (GRA)
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Roy, Satadru
Traditional approaches to design and optimize a new system, often, use a system-centric objective and do not take into consideration how the operator will use this new system alongside of other existing systems. This "hand-off" between the design of the new system and how the new system operates alongside other systems might lead to a sub-optimal performance with respect to the operator-level objective. In other words, the system that is optimal for its system-level objective might not be best for the system-of-systems level objective of the operator. Among the few available references that describe attempts to address this hand-off, most follow an MDO-motivated subspace decomposition approach of first designing a very good system and then provide this system to the operator who decides the best way to use this new system along with the existing systems. The motivating example in this dissertation presents one such similar problem that includes aircraft design, airline operations and revenue management "subspaces". The research here develops an approach that could simultaneously solve these subspaces posed as a monolithic optimization problem. The monolithic approach makes the problem a Mixed Integer/Discrete Non-Linear Programming (MINLP/MDNLP) problem, which are extremely difficult to solve. The presence of expensive, sophisticated engineering analyses further aggravate the problem. To tackle this challenge problem, the work here presents a new optimization framework that simultaneously solves the subspaces to capture the "synergism" in the problem that the previous decomposition approaches may not have exploited, addresses mixed-integer/discrete type design variables in an efficient manner, and accounts for computationally expensive analysis tools. The framework combines concepts from efficient global optimization, Kriging partial least squares, and gradient-based optimization. This approach then demonstrates its ability to solve an 11 route airline network
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Leakage Account for Radial Face Contact Seal in Aircraft Engine Support
Vinogradov, A. S.; Sergeeva, T. V.
2018-01-01
The article is dedicated to the development of a methodology for the radial face contact seal design taking into consideration the supporting elements deformations in different aircraft engine operating modes. Radial face contact seals are popular in the aircraft engines bearing support. However, there are no published leakage calculation methodologies of these seals. Radial face contact seal leakage is determined by the gap clearance in the carbon seal ring split. In turn, the size gap clearance depends on the deformation of the seal assembly parts and from the engine operation. The article shows the leakage detection sequence in the intershaft radial face contact seal of the compressor support for take-off and cruising modes. Evaluated calculated leakage values (2.4 g/s at takeoff and 0.75 g/s at cruising) go with experience in designing seals.
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14 CFR 49.11 - FAA Aircraft Registry.
2010-01-01
... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false FAA Aircraft Registry. 49.11 Section 49.11... AIRCRAFT TITLES AND SECURITY DOCUMENTS General § 49.11 FAA Aircraft Registry. To be eligible for recording, a conveyance must be mailed to the FAA Aircraft Registry, Department of Transportation, Post Office...
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2015-10-01
FORD CLASS AIRCRAFT CARRIER Poor Outcomes Are the Predictable Consequences of the Prevalent Acquisition Culture...2. REPORT TYPE 3. DATES COVERED 00-00-2015 to 00-00-2015 4. TITLE AND SUBTITLE Ford Class Aircraft Carrier: Poor Outcomes Are the Predictable...This Study The Navy set ambitious goals for the Ford -class program, including an array of new technologies and design features that were intended
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Creating a Test-Validated Finite-Element Model of the X-56A Aircraft Structure
Pak, Chan-Gi; Truong, Samson
2014-01-01
Small modeling errors in a finite-element model will eventually induce errors in the structural flexibility and mass, thus propagating into unpredictable errors in the unsteady aerodynamics and the control law design. One of the primary objectives of the X-56A Multi-Utility Technology Testbed aircraft is the flight demonstration of active flutter suppression and, therefore, in this study, the identification of the primary and secondary modes for the structural model tuning based on the flutter analysis of the X-56A aircraft. The ground-vibration test-validated structural dynamic finite-element model of the X-56A aircraft is created in this study. The structural dynamic finite-element model of the X-56A aircraft is improved using a model-tuning tool. In this study, two different weight configurations of the X-56A aircraft have been improved in a single optimization run. Frequency and the cross-orthogonality (mode shape) matrix were the primary focus for improvement, whereas other properties such as c.g. location, total weight, and off-diagonal terms of the mass orthogonality matrix were used as constraints. The end result was an improved structural dynamic finite-element model configuration for the X-56A aircraft. Improved frequencies and mode shapes in this study increased average flutter speeds of the X-56A aircraft by 7.6% compared to the baseline model.
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Fluid-structure interaction by the mixed SPH-FE method with application to aircraft ditching
Directory of Open Access Journals (Sweden)
P Groenenboom
2016-10-01
Full Text Available This paper deals with numerical simulation of fluid-structure interaction as it occurs during aircraft ditching – an emergency condition where an aircraft is forced to land on water. The work is motivated by the requirement for aircraft manufactures to analyze ditching as part of the aircraft certification process requested by airworthiness authorities. The strong interaction of highly non-linear fluid flow phenomena and structural responses requires a coupled solution of this transient problem. Therefore, an approach coupling Smoothed Particle Hydrodynamics and the Finite Element method within the commercial, explicit software Virtual Performance Solutions has been pursued. In this paper, several innovative features are presented, which allow for accurate and efficient solution. Finally, exemplary numerical results are successfully compared to experimental data from a unique test campaign of guided ditching tests at quasi-full scale impact conditions. It may be concluded that through the application of state-of-the-art numerical techniques it has become possible to simulate the coupled fluidstructure interaction as occurring during ditching. Therefore, aircraft manufacturers may significantly benefit from numerical analysis for design and certification purposes.
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Wlezien, R. W.; Horner, G. C.; McGowan, A. R.; Padula, S. L.; Scott, M. A.; Silcox, R. J.; Simpson, J. O.
1998-01-01
In the last decade smart technologies have become enablers that cut across traditional boundaries in materials science and engineering. Here we define smart to mean embedded actuation, sensing, and control logic in a tightly coupled feedback loop. While multiple successes have been achieved in the laboratory, we have yet to see the general applicability of smart devices to real aircraft systems. The NASA Aircraft Morphing program is an attempt to couple research across a wide range of disciplines to integrate smart technologies into high payoff aircraft applications. The program bridges research in seven individual disciplines and combines the effort into activities in three primary program thrusts. System studies are used to assess the highest- payoff program objectives, and specific research activities are defined to address the technologies required for development of smart aircraft systems. In this paper we address the overall program goals and programmatic structure, and discuss the challenges associated with bringing the technologies to fruition.
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Schoess, Jeffrey N.; Seifert, Greg; Paul, Clare A.
1996-05-01
The smart aircraft fastener evaluation (SAFE) system is an advanced structural health monitoring effort to detect and characterize corrosion in hidden and inaccessible locations of aircraft structures. Hidden corrosion is the number one logistics problem for the U.S. Air Force, with an estimated maintenance cost of $700M per year in 1990 dollars. The SAFE system incorporates a solid-state electrochemical microsensor and smart sensor electronics in the body of a Hi-Lok aircraft fastener to process and autonomously report corrosion status to aircraft maintenance personnel. The long-term payoff for using SAFE technology will be in predictive maintenance for aging aircraft and rotorcraft systems, fugitive emissions applications such as control valves, chemical pipeline vessels, and industrial boilers. Predictive maintenance capability, service, and repair will replace the current practice of scheduled maintenance to substantially reduce operational costs. A summary of the SAFE concept, laboratory test results, and future field test plans is presented.
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Weasel works SA-150: Design study of a 100 to 150 passenger transport aircraft
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.
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2010-07-20
...- Sport Aircraft; Modifications to Rules for Sport Pilots and Flight Instructors With a Sport Pilot Rating... rule; OMB approval of information collection. SUMMARY: This document announces the Office of Management... rule, ``Certification of Aircraft and Airmen for the Operation of Light-Sport Aircraft; Modifications...
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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.
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Impact analysis of composite aircraft structures
Pifko, Allan B.; Kushner, Alan S.
1993-01-01
The impact analysis of composite aircraft structures is discussed. Topics discussed include: background remarks on aircraft crashworthiness; comments on modeling strategies for crashworthiness simulation; initial study of simulation of progressive failure of an aircraft component constructed of composite material; and research direction in composite characterization for impact analysis.
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FAULT DIAGNOSIS OF AN AIRCRAFT CONTROL SURFACES WITH AN AUTOMATED CONTROL SYSTEM
Directory of Open Access Journals (Sweden)
Blessing D. Ogunvoul
2017-01-01
Full Text Available This article is devoted to studying of fault diagnosis of an aircraft control surfaces using fault models to identify specific causes. Such failures as jamming, vibration, extreme run out and performance decrease are covered.It is proved that in case of an actuator failure or flight control structural damage, the aircraft performance decreases significantly. Commercial aircraft frequently appear in the areas of military conflicts and terrorist activity, where the risk of shooting attack is high, for example in Syria, Iraq, South Sudan etc. Accordingly, it is necessary to create and assess the fault model to identify the flight control failures.The research results demonstrate that the adequate fault model is the first step towards the managing the challenges of loss of aircraft controllability. This model is also an element of adaptive failure-resistant management model.The research considers the relationship between the parameters of an i th state of a control surface and its angular rate, also parameters classification associated with specific control surfaces in order to avoid conflict/inconsistency in the determination of a faulty control surface and its condition.The results of the method obtained in this article can be used in the design of an aircraft automated control system for timely identification of fault/failure of a specific control surface, that would contribute to an effective role aimed at increasing the survivability of an aircraft and increasing the acceptable level of safety due to loss of control.
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8 CFR 1280.21 - Seizure of aircraft.
2010-01-01
... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Seizure of aircraft. 1280.21 Section 1280... REGULATIONS IMPOSITION AND COLLECTION OF FINES § 1280.21 Seizure of aircraft. Seizure of an aircraft under the... that its value is less than the amount of the fine which may be imposed. If seizure of an aircraft for...
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8 CFR 280.21 - Seizure of aircraft.
2010-01-01
... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Seizure of aircraft. 280.21 Section 280.21... OF FINES § 280.21 Seizure of aircraft. Seizure of an aircraft under the authority of section 239 of... than the amount of the fine which may be imposed. If seizure of an aircraft for violation of section...
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GRAPHICAL MODELS OF THE AIRCRAFT MAINTENANCE PROCESS
Directory of Open Access Journals (Sweden)
Stanislav Vladimirovich Daletskiy
2017-01-01
Full Text Available The aircraft maintenance is realized by a rapid sequence of maintenance organizational and technical states, its re- search and analysis are carried out by statistical methods. The maintenance process concludes aircraft technical states con- nected with the objective patterns of technical qualities changes of the aircraft as a maintenance object and organizational states which determine the subjective organization and planning process of aircraft using. The objective maintenance pro- cess is realized in Maintenance and Repair System which does not include maintenance organization and planning and is a set of related elements: aircraft, Maintenance and Repair measures, executors and documentation that sets rules of their interaction for maintaining of the aircraft reliability and readiness for flight. The aircraft organizational and technical states are considered, their characteristics and heuristic estimates of connection in knots and arcs of graphs and of aircraft organi- zational states during regular maintenance and at technical state failure are given. It is shown that in real conditions of air- craft maintenance, planned aircraft technical state control and maintenance control through it, is only defined by Mainte- nance and Repair conditions at a given Maintenance and Repair type and form structures, and correspondingly by setting principles of Maintenance and Repair work types to the execution, due to maintenance, by aircraft and all its units mainte- nance and reconstruction strategies. The realization of planned Maintenance and Repair process determines the one of the constant maintenance component. The proposed graphical models allow to reveal quantitative correlations between graph knots to improve maintenance processes by statistical research methods, what reduces manning, timetable and expenses for providing safe civil aviation aircraft maintenance.
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NDT applications in the aircraft industry
International Nuclear Information System (INIS)
Aguilar, E.C.
1994-01-01
Non-destructive testing (NDT) in the aircraft industry is used primarily to detect process defects in the manufacturing stage and failure defects in the in-service stage. Inspection techniques such as X- or gamma ray radiography are used for examination. Eddy current and ultrasonic are applied for examination, fluorescent penetrant and magnetic particles are applied for examination of aircraft and engine. With the wide scope of application, this paper discussed one type of NDT that is much used in aircraft being the latest technique in aircraft manufacturing. 1 fig
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Composite materials for aircraft structures
National Research Council Canada - National Science Library
Baker, A. A; Dutton, Stuart; Kelly, Donald
2004-01-01
... materials for aircraft structures / Alan Baker, Stuart Dutton, and Donald Kelly- 2nd ed. p. cm. - (Education series) Rev. ed. of: Composite materials for aircraft structures / edited by B. C. Hos...
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Study of advanced rotary combustion engines for commuter aircraft
Berkowitz, M.; Jones, C.; Myers, D.
1983-01-01
Performance, weight, size, and maintenance data for advanced rotary aircraft engines suitable for comparative commuter aircraft system evaluation studies of alternate engine candidates are provided. These are turbocharged, turbocompounded, direct injected, stratified charge rotary engines. Hypothetical engines were defined (an RC4-74 at 895 kW and an RC6-87 at 1490 kW) based on the technologies and design approaches used in the highly advanced engine of a study of advanced general aviation rotary engines. The data covers the size range of shaft power from 597 kW (800 hp) to 1865 kW (2500 hp) and is in the form of drawings, tables, curves and written text. These include data on internal geometry and configuration, installation information, turbocharging and turbocompounding arrangements, design features and technologies, engine cooling, fuels, scaling for weight size BSFC and heat rejection for varying horsepower, engine operating and performance data, and TBO and maintenance requirements. The basic combustion system was developed and demonstrated; however the projected power densities and performance efficiencies require increases in engine internal pressures, thermal loading, and rotative speed.
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Klein, S.; Smrcek, L.
2009-01-01
This paper is primarily concerned with the inverted design process and manufacture of a flying car prototype which can overcome the problem of traffic management in the world today. A possible solution to the problem of overcrowded roads would be to design a flying or hovering car. Given technological advances in aircraft construction, navigation and operation, flying cars or personal aircraft are now a feasible proposition. The viability of such a concept was investigated in terms of produci...
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The High Level Mathematical Models in Calculating Aircraft Gas Turbine Engine Parameters
Directory of Open Access Journals (Sweden)
Yu. A. Ezrokhi
2017-01-01
Full Text Available The article describes high-level mathematical models developed to solve special problems arising at later stages of design with regard to calculation of the aircraft gas turbine engine (GTE under real operating conditions. The use of blade row mathematics models, as well as mathematical models of a higher level, including 2D and 3D description of the working process in the engine units and components, makes it possible to determine parameters and characteristics of the aircraft engine under conditions significantly different from the calculated ones.The paper considers application of mathematical modelling methods (MMM for solving a wide range of practical problems, such as forcing the engine by injection of water into the flowing part, estimate of the thermal instability effect on the GTE characteristics, simulation of engine start-up and windmill starting condition, etc. It shows that the MMM use, when optimizing the laws of the compressor stator control, as well as supplying cooling air to the hot turbine components in the motor system, can significantly improve the integral traction and economic characteristics of the engine in terms of its gas-dynamic stability, reliability and resource.It ought to bear in mind that blade row mathematical models of the engine are designed to solve purely "motor" problems and do not replace the existing models of various complexity levels used in calculation and design of compressors and turbines, because in “quality” a description of the working processes in these units is inevitably inferior to such specialized models.It is shown that the choice of the mathematical modelling level of an aircraft engine for solving a particular problem arising in its designing and computational study is to a large extent a compromise problem. Despite the significantly higher "resolution" and information ability the motor mathematical models containing 2D and 3D approaches to the calculation of flow in blade machine
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IDENTIFICATION OF AIRCRAFT HAZARDS
International Nuclear Information System (INIS)
K.L. Ashley
2005-01-01
Aircraft hazards were determined to be potentially applicable to a repository at Yucca Mountain in the ''Monitored Geological Repository External Events Hazards Screening Analysis'' (BSC 2004, Section 6.4.1). That determination was conservatively based on limited knowledge of flight data in the area of concern and on crash data for aircraft of the type flying near Yucca Mountain. The purpose of this report is to identify specific aircraft hazards that may be applicable to a Monitored Geologic Repository (MGR) at Yucca Mountain using NUREG-0800, ''Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants'' (NRC 1987, Section 3.5.1.6), as guidance for the inclusion or exclusion of identified aircraft hazards. NUREG-0800 is being used here as a reference because some of the same considerations apply. The intended use of this report is to provide inputs for further screening and analysis of the identified aircraft hazards based on the criteria that apply to Category 1 and 2 event sequence analyses as defined in 10 CFR 63.2 (see Section 4). The scope of this technical report includes the evaluation of military, private, and commercial use of airspace in the 100-mile regional setting of the MGR at Yucca Mountain with the potential for reducing the regional setting to a more manageable size after consideration of applicable screening criteria (see Section 7)
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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).
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31 CFR 560.528 - Aircraft safety.
2010-07-01
... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Aircraft safety. 560.528 Section 560..., Authorizations and Statements of Licensing Policy § 560.528 Aircraft safety. Specific licenses may be issued on a... the safety of civil aviation and safe operation of U.S.-origin commercial passenger aircraft. ...
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Deicing System Protects General Aviation Aircraft
2007-01-01
Kelly Aerospace Thermal Systems LLC worked with researchers at Glenn Research Center on deicing technology with assistance from the Small Business Innovation Research (SBIR) program. Kelly Aerospace acquired Northcoast Technologies Ltd., a firm that had conducted work on a graphite foil heating element under a NASA SBIR contract and developed a lightweight, easy-to-install, reliable wing and tail deicing system. Kelly Aerospace engineers combined their experiences with those of the Northcoast engineers, leading to the certification and integration of a thermoelectric deicing system called Thermawing, a DC-powered air conditioner for single-engine aircraft called Thermacool, and high-output alternators to run them both. Thermawing, a reliable anti-icing and deicing system, allows pilots to safely fly through ice encounters and provides pilots of single-engine aircraft the heated wing technology usually reserved for larger, jet-powered craft. Thermacool, an innovative electric air conditioning system, uses a new compressor whose rotary pump design runs off an energy-efficient, brushless DC motor and allows pilots to use the air conditioner before the engine even starts