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Viewing 1 to 30 of 7401
2004-11-02
Technical Paper
2004-01-3092
Zenovy S. Wowczuk, Kenneth H. Means, Victor H. Mucino, Gregory J. Thompson, James Smith, Jeffery R.X Auld, James E. Smith, Adam Naternicola, Lawrence Anthony Feragotti, Bruce J. Corso
The development of a standardized roll-on, roll-off (RoRo) sensor pallet system for a C-130 aircraft was conceived by the National Guard and the Counter Narco-Terrorism Technology Development Office to assist in counterdrug reconnaissance activities within the United States and surveillance and reconnaissance missions worldwide. West Virginia University was contracted to perform the design and development of this system because of their innovative design ideas. Before development, the design parameters were established by these two DoD agencies, their mission requirements and by the limitations of the C-130 aircraft. These limitations include using Commercial off the Shelf (COTS) and Government off the Shelf (GOTS) items when developing the system that must be universal on all C-130 aircrafts variants B thru H. Further design criteria are by the limitations of the C-130 aircraft and its existing mission requirements.
2004-11-16
Technical Paper
2004-01-3315
Alexandre de Almeida Guimarães
It is clearly perceived the exponential growth of on-board electronics on several technological segments. On aerospace segment that is not different. Besides those propulsion and navigation fundamentals systems, necessary on most part of the aircrafts, many complex electronic systems are required: for the treatment of information sent by either landed equipments or other aircrafts (often found on military applications), and for comfort and entertainment systems (most related to passenger transportation applications). In any case, the amount of available and exchangeable information between these systems is fairly huge. Such data exchange would be easier performed if were made through the application of a communication protocol. This paper lists and analyses the communication protocols used by most part of the current and future aircrafts. The intention of this document is to be a study guideline of avionics related protocols.
2004-11-16
Technical Paper
2004-01-3415
Marcelo Lopes de Oliveira e Souza, Gilberto da Cunha Trivelato
In this work we discuss some types of simulation environments and laboratories, their characteristics and applications to the simulation and control of aerospace vehicles. This includes: the basic definitions, types and characteristics of simulators and simulations (physical, computational, hybrid, etc.; discrete events, discrete time, continuous time, etc; deterministic, stochastic, etc.) their basic compromise (simplicity × fidelity), their man-machine interfaces and interactions (virtual, constructive, live, etc.), their evolution law (time, events, mixed, etc.), their architectures (“stand-alone”, PIL, HIL, MIL, DIS, HLA, etc.), and especially, their environments (discrete, continuous, hybrid, etc.) and laboratories (physical, computational, hybrid, etc.), and their applications to the simulation and control of aerospace vehicles. This is illustrated by some examples driven from the aerospace industry.
2013-10-07
Technical Paper
2013-36-0353
Luciano Magno Frágola Barbosa, José Eduardo Mautone de Barros
The aim of this work is to present the preliminary configuration design studies for an unmanned, lightweight (less than 15 kg), supersonic research aircraft. The studies comprise the aircraft typical mission, the aerodynamic and structural arrangement, preliminary performance, as well as mass distribution. The aircraft, an Unmanned Air Vehicle, or “UAV”, is named as Pohox (“arrow” in Maxakali indian language). It is intended to be the flying test bed for a multicycle engine capable to provide thrust in subsonic, transonic and supersonic regimes. In order to provide validation of the analysis tools, flight performance characteristics of a known, high speed aircraft - North American X-15 - have been also evaluated and compared with the available flight test data. The present analysis is an important step towards the aircraft detailed definition. And the features associated with the configuration obtained are good indications of the technical feasibility of this supersonic UAV.
2014-04-01
Technical Paper
2014-01-0488
Peter Kempf
Abstract Discuss the basics of posturing and positioning of the full range of occupants necessary to cover the required anthropometric demographics in combat vehicles, both ground and air, since there are similarities to both and that they are both very different than the traditional automotive packaging scenarios. It is based on the Eye Reference Point and the Design Eye Point. Discuss the three Reach Zones: Primary, Secondary and Tertiary. Discuss Vision Zones and potentially ground intercepts. Discuss body clearances, both static and dynamic. Discuss the basic effects of packaging occupants with body armor with respect to SRP's and MSRP's.
2011-05-17
Technical Paper
2011-01-1701
Tongan Wang, John Maxon
Statistical Energy Analysis (SEA) has been used widely by industry and academia for more than 20 years to predict the mid-to-high frequency range behavior of complex acoustic systems. At Gulfstream Aerospace Corporation (GAC), SEA models have been developed to predict the interior cabin noise levels of completed Gulfstream aircraft. These models are also used for acoustic evaluations of design changes prior to implementation as well as a diagnostic tool for investigating noise and vibration issues. Throughout the development of the SEA models, extensive experimental testing in GAC's Acoustic Test Facility (ATF) was conducted on numerous aircraft components represented in the models. This paper demonstrates the importance of using experimental data to improve the accuracy of the SEA predictions by accurately adjusting the material properties and acoustic parameters of the SEA model to better match the ATF experimental data.
2011-05-17
Technical Paper
2011-01-1704
Nickolas Vlahopoulos, Geng Zhang, Ricardo Sbragio
Vehicle design is a complex process requiring interactions and exchange of information among multiple disciplines such as fatigue, strength, noise, safety, etc. Simulation models are employed for assessing and potentially improving a vehicle's performance in individual technical areas. Challenges arise when designing a vehicle for improving mutually competing objectives, satisfying constraints from multiple engineering disciplines, and determining a single set of values for the vehicle's characteristics. It is of interest to engage simulation models from the various engineering disciplines in an organized and coordinated manner for determining a design configuration that provides the best possible performance in all disciplines. The multi-discipline design process becomes streamlined when the simulation methods integrate well with finite element or computer aided design models.
2011-05-17
Technical Paper
2011-01-1733
Kurt Veggeberg, Michael James
Military jet aircraft expose both ground maintenance personnel and the community to high levels of noise. The U.S. Department of Defense is funding research to develop advanced modeling tools for noise reduction techniques and community noise exposure. A large-scale microphone array for portable near-field acoustic holography (NAH) and data acquisition system was created for this purpose. The system was designed for measuring high-amplitude jet noise from current and next-generation military aircraft to provide model refinement and benchmarking, evaluate performance of noise control devices, and predict ground maintenance personnel and community noise exposure. The acoustical instrumentation system was designed to be easy to use with scalable data processing as the primary focus. The data acquisition system allowed up to 152 channels simultaneously sampled at a rate of 96 kHz.
2011-05-17
Technical Paper
2011-01-1647
Kristopher Lynch, John Maxon
Gulfstream Aerospace Corporation (GAC) owns and operates an Acoustic Test Facility (ATF) in Savannah, GA. The ATF consists of a Reverberation Chamber, Hemi-Anechoic Chamber, and a Control Room. Types of testing conducted in the ATF include Transmission Loss, Sound Power, and Vibration testing. In addition to accommodating typical types of acoustic testing, the ATF has some unique capabilities. The ATF can be used to conduct testing at cold temperatures representative of up to 45,000 ft flight altitude, while simultaneously taking Transmission Loss measurements of the chilled test sample. Additionally, the ATF has the capability of conducting Transmission Loss testing of a full mockup of the aircraft sidewall, including a section of fuselage, all the thermal/acoustic materials up to and including the interior decorative panel. A sound source capable of very high amplitudes at high frequencies is required to obtain good measurements from testing multiple wall systems such as this.
2011-05-17
Technical Paper
2011-01-1617
T.S. Miller, S.W. Lee, G. Holup, J.M. Gallman, M.J. Moeller
The turbulent boundary layer (TBL) that forms on the outer skin of the aircraft in flight is a significant source of interior noise. However, the existing quiet test facilities capable of measuring the TBL wall pressure fluctuations tend to be at low Mach numbers. The objective of this study was to develop a new inlet for an existing six inch square (or 6×6) flow duct that would be adequately free from facility noise to study the TBL wall pressure fluctuations at higher, subsonic Mach numbers. First, the existing flow duct setup was used to measure the TBL wall pressure fluctuations. Then the modified inlet was successfully used to make similar measurements up to Mach number of 0.6. These measurements will be used in the future to validate wall pressure spectrum models for interior noise analysis programs such as statistical energy analysis (SEA) and dynamic energy analysis (DEA).
1999-10-19
Technical Paper
1999-01-5639
Mark A. Hale, Dimitri N. Mavris, Dennis L. Carter
The Conceptual Aerospace Systems Design and Analysis Toolkit (CASDAT) provides a baseline assessment capability for the Air Force Research Laboratory. The historical development of CASDAT is of benefit to the design research community because considerable effort was expended in the classification of the analysis tools. Its implementation proves to also be of importance because of the definition of assessment use cases. As a result, CASDAT is compatible with accepted analysis tools and can be used with state-of-the-art assessment methods, including technology forecasting and probabilistic design.
1999-10-19
Technical Paper
1999-01-5659
R. Kruk, N. Link, L. Reid, S. Jennings
The Enhanced/Synthetic Vision System (E/SVS) is a Technology Demonstrator (TD) project supported by the Chief, Research and Development of the Canadian Department of National Defence. E/SVS displays an augmented visual scene to the pilot that includes three separate image sources: a synthetic computer - generated terrain image; an enhanced visual image from an electro-optical sensor (fused as an inset); and aircraft instrument symbology, all displayed to the pilot on a Helmet Mounted Display (HMD). The synthetic component of the system provides a 40 degree vertical by 80 degree horizontal image of terrain and local features. The enhanced component digitizes imagery from electro-optic sensors and fuses the sensor image as an inset (20 degrees by 25 degrees) within the synthetic image. Symbology can be overlaid in any location within the synthetic field-of-view and may be head, aircraft, target or terrain referenced.
1999-10-19
Technical Paper
1999-01-5654
Barth W. Shenk
An empirically based, analytical tool for calculating lift, drag and pitching moment of tilting wing configurations is presented, and used to develop the general characteristics of the Compound Tilting Wing (CTW), a variation on the conventional tilting wing configuration. The CTW utilizes an inboard leading edge extension, which acts as a canard when the wing tilts to augment pitch control during low speed operations and conforms to the wing at zero tilt. This scheme allows the designer more degrees of freedom for overall configuration layout and propulsion system integration for STOL design.
1999-10-19
Technical Paper
1999-01-5607
R Bruce Lumsden, Gareth D Padfield, Carole D Braby-Deighton
The paper takes a total systems approach to the human factors challenges at the helicopter-ship dynamic interface. It examines the problems of operating large helicopters from small ships in all weather conditions from the start of the mission to completion with due emphasis on the launch and recovery phases. Research taking place at DERA Bedford in support of current and future naval operations is outlined. Although the prime focus is Royal Navy Anti-submarine Warfare operations, the paper also considers present and future maritime and marinised helicopter types. The paper is written from the perspective of developing requirements and reducing risk by demonstrating technical solutions. The main focus of the paper is the recovery from completion of task to securing in the ship’s hangar. It addresses the aspects of automatic flight path management and flight control systems and the role of automation during the recovery process, particularly in the case of the single pilot aircraft.
1999-10-19
Technical Paper
1999-01-5606
A. Leger, C. Gardelle, G. Bruniaux
Abstract Advanced binocular Helmet Mounted Displays (HMD) capable of bisensor operation (I2 tubes and video images) with overlaid symbology have been developed for military use in various helicopters. Extensive flight testing of such helmets, as the French TOPOWL®, have provided so far a considerable amount of data relatively to Night Vision System design and use. Design options allowing improved mass and Center of Gravity in regard of classical NVG, as folded optics and visor projection, have been shown to give very effective results. Performance in various flight conditions, including fog, snow and obstacles, has been quite thoroughly investigated. Training issues with I2 and head-steered thermal imagery have also been addressed during test flight. Lessons learned from test flight open interesting possibilities for further use of such systems in civilian rotorcraft operation, provided acceptably low cost solutions could be achieved.
1999-10-19
Technical Paper
1999-01-5608
E. Theunissen, G. Sachs
The selection of the design parameters of a perspective flightpath display must take into account the operational capabilities of the vehicle to be controlled. As a result, designs of perspective flightpath displays that have been optimized for fixed-wing aircraft may need to be modified in order to be useful for advanced approach procedures with tiltrotors. This paper discusses potential changes that are required as a result of the different range of flightpath angles used in approach trajectories and the different range of velocities.
1999-10-19
Technical Paper
1999-01-5619
Richard M. Wood, Steven X. S. Bauer
A 1990 research program that focused on the development of advanced aerodynamic control effectors (AACE) for military aircraft has been reviewed and summarized. Data are presented for advanced planform, flow control, and surface contouring technologies. The data show significant increases in lift, reductions in drag, and increased control power, compared to typical aerodynamic designs. The results presented also highlighted the importance of planform selection in the design of a control effector suite. Planform data showed that dramatic increases in lift (> 25%) can be achieved with multiple wings and a sawtooth forebody. Passive porosity and micro drag generator control effector data showed control power levels exceeding that available from typical effectors (moving surfaces). Application of an advanced planform to a tailless concept showed benefits of similar magnitude as those observed in the generic studies.
1999-10-19
Technical Paper
1999-01-5546
Archie E. Dillard
The rapid implementation of multifunction display (MFD) designs in new aircraft has increased the need for aerospace recommended practices (ARP) for use by manufacturers and users. The large amount of information available for display creates a number of human factors problems that must be addressed in the design phase in order to produce a safe and usable display system. Color, clutter, prioritization, switching, symbology, and compatibility are only a few of the areas that require guidance. This presentation will review the work to date by the SAE G-10 Multifunction Display Subcommittee on an ARP that will address these issues and others.
1999-10-19
Technical Paper
1999-01-5512
Leger, Aymeric, H. Audrezet, P. Alba
HUD-based hybrid landing systems developed by SEXTANT Avionics have been successfully certified for AEROPOSTALE and ALITALIA. The philosophy of such system is to offer minima reductions (down to DH 35 ft and RVR 125 m) with automatic Cat 3A operations. From a human factors stand point, the basis of such an approach is that improved situational awareness provided by the HUD allows to maintain an acceptable safety level for operations despite lower DH and visibility. Though, it is well known that switching from a supervisory control mode to a manual control mode under time pressure is a very serious challenge for the human operator. In this regard, numerous human factors issues were addressed during the concept validation phase and results applied to certification.
1999-10-19
Technical Paper
1999-01-5531
Christopher McFarland, Jason McClurg, William McClelland, Steven A. Brandt
The General Atomics RQ-1A Predator has become an essential tool for battlefield commanders. However, its low maximum speed and poor performance in rain and icing conditions limit its usefulness. In the Spring of 1999, two 10-student sections of the aircraft design class at the United States Air Force Academy studied ways to improve Predator’s usefulness. They determined that small turbine engines, electro-expulsive de-icing systems, and several simple aerodynamic refinements would significantly improve Predator’s capabilities. These results and the methods used to generate them are described.
1999-10-19
Technical Paper
1999-01-5530
Ray Whitford
Different feasibility studies have been carried out over several years at the Royal Military College of Science (RMCS) into medium military airlifters aimed, in essence at replacing the C-130. The studies, each occupying a nominal 1,500 manhours (but probably 50% more) formed part of the final year of the AeroMechanical B.Eng degree at RMCS. The intention of this paper is to draw together their major findings and deals predominantly with the topics of: cargo hold sizing and body aerodynamics, powerplant selection, weight and performance.
1999-10-19
Technical Paper
1999-01-5503
John Paterson
Survivability of combat aircraft has significantly increased with the use of low observable (LO) technology. This technology has dramatically reduced the ability of an air defense to detect, track, intercept and destroy a penetrating stealth aircraft. The Iraqi Desert Storm conflict demonstrated to the world that LO aircraft are a significant threat and they are developing counters to that threat. Many countries are rapidly improving their air defenses by purchasing more advanced radars, surface-to-air missiles (SAM) and integrated air defense systems (IADS). Another defense technique is to concentrate defense elements so there is significant overlap, making it difficult for even stealth aircraft to penetrate. A counter to these defense improvements and highly defended areas is already being used by non-stealth aircraft: standoff weapons. Stealth aircraft can penetrate a hostile airspace and use standoff weapons to attack heavily defended areas with little survivability risk.
1999-10-19
Technical Paper
1999-01-5506
Thomas R. Yechout, Jonathan C. Dowty
Approximately 120 hours of wind tunnel testing were accomplished to determine the drag contributions of various external protuberances on the AC-130H Gunship and to recommend modifications to achieve optimal drag reduction potential. Also, the operational impact of the recommended configuration was quantified using a performance modeling code. The overall objective of this effort was to establish a solid foundation via experimental and computational ground efforts to support flight test of drag reduction modifications to an aircraft. Thirteen basic AC-130H protuberances were evaluated to determine their incremental drag. A recommended reduced-drag configuration was developed which provided a drag reduction potential of 58.2 counts.
2011-10-04
Technical Paper
2011-36-0088
Jairo Eduardo Moraes Siqueira, Marcelo Lopes de Oliveira e Souza
In this work, the problem of fault detection, isolation, and reconfiguration (FDIR) for Networked-Control Systems (NCS) of aerospace vehicles is discussed. The concept of fault-tolerance is introduced from a generic structure, and a review on quantitative and qualitative methods (state estimation, parameter estimation, parity space, statistic testing, neural networks, etc.) for FDIR is then performed. Afterwards, the use of networks as loop-closing elements is introduced, followed by a discussion on advantages (flexibility, energy demand, etc.) and challenges (networks effects on performance, closed-loop fault-effects on safety, etc.) represented thereby. Finally, examples of applications on aerospace vehicles illustrate the importance of the discussion herein exposed.
2011-10-04
Technical Paper
2011-36-0129
Luiz Carlos Sandoval Góes, Eduardo Augusto Gallo
It was purposed in this study the use of thermal comfort index as feedback parameter for multivariable control of aeronautical air conditioned system. Simulating the developed thermal model, the efficiency gain by using this control law was observed by comparing it with standard control models.
2011-06-13
Technical Paper
2011-38-0001
Jie Xiao, Katherine E. Mackie, Joseph H. Osborne, Jill Seebergh, Santanu Chaudhuri
In-flight icing occurs when supercooled water droplets suspended in the atmosphere impinge on cold aircraft surfaces. Thin layers of accreted ice significantly increase aerodynamic drag while thick layers of ice severely alter the aerodynamics of control surfaces and lift. Chunks of ice can break away from the airframe and cowlings and be ingested into engines causing considerable damage. Developing durable surfaces that prevent the nucleation of supercooled water or reduce ice adhesion to a point where airstream shear forces can remove it would allow the design of a more robust, energy efficient deicing/anti-icing system for aircraft and other applications. In this work, a simulations based framework is developed to predict anti-icing performance of various nanocomposite coatings under the in-flight environment.
2011-06-13
Technical Paper
2011-38-0013
Marco Fossati, Wagdi G. Habashi, Guido Baruzzi
The high computational cost of 3-D viscous turbulent aero-icing simulations is one of the main limitations to address in order to more extensively use computational fluid dynamics to explore the wide variety of icing conditions to be tested before achieving aircraft airworthiness. In an attempt to overcome the computational burden of these simulations, a Reduced Order Modeling (ROM) approach, based on Proper Orthogonal Decomposition (POD) and Kriging interpolation techniques, is applied to the computation of the impingement pattern of supercooled large droplets (SLD) on aircraft. Relying on a suitable database of high fidelity full-order simulations, the ROM approach provides a lower-order approximation of the system in terms of a linear combination of appropriate functions. The accuracy of the resulting surrogate solution is successfully compared to experimental and CFD results for sample 2-D problems and then extended to a typical 3-D case.
2011-06-13
Technical Paper
2011-38-0015
Robert Narducci, Tonja Reinert
The desire to operate rotorcraft in icing conditions has renewed the interest in developing high-fidelity analysis methods to predict ice accumulation and the ensuing rotor performance degradation. A subset of providing solutions for rotorcraft icing problems is predicting two-dimensional ice accumulation on rotor airfoils. While much has been done to predict ice for fixed-wing airfoil sections, the rotorcraft problem has two additional challenges: first, rotor airfoils tend to experience flows in higher Mach number regimes, often creating glaze ice which is harder to predict; second, rotor airfoils oscillate in pitch to produce balance across the rotor disk. A methodology and validation test cases are presented to solve the rotor airfoil problem as an important step to solving the larger rotorcraft icing problem. The process couples Navier-Stokes CFD analysis with the ice accretion analysis code, LEWICE3D.
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