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Viewing 1 to 30 of 3962
2004-11-02
Technical Paper
2004-01-3099
Gerald M. Angle, F. Andy Pertl, James E. Smith, Bruce J. Corso
Predicting the aerodynamic forces in the wake of an object can be difficult using theoretical and computational methods. This is particularly true for airframes that have multiple engines and whose flight envelope involves the use of large control surfaces. One such aircraft is the C-130 which adds the further complication of a rear cargo door and ramp. Modeling the wake near the rear of this aircraft can be difficult and inaccurate unless validated against actual flight data. For this study a simple test apparatus, developed by the authors, was used to measure the velocity profile in the wake area of the rear cargo door of such an aircraft. The test apparatus contained 32 pressure ports, one of these ports was assigned to a static pressure probe. All pressures were referenced to an additional static pressure measured at the edge of the cargo ramp. The remaining, 31 pressure probes were distributed regularly between three vertical rake assemblies.
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
2013-36-0460
Shirley Mota Pedreira, David Fernando Castillo Zuñiga, Jany Freire de Lima, Waldo Acioli Falcão de Alencar, Cristiane Aparecida Martins
This paper proposes the study of the first bending mode of the wing's UAV Vector-P using impact methodology. The data acquisition and signal processing was implemented using LabView. The analysis provides frequency response, but needs an algorithm which was made in MATLAB®. This algorithm, called Model Identification, also provide eigenvalues and eigenvectors. MEMS accelerometers were used for input measurement and an impact hammer for output. In this work, the accelerometers were calibrated based on ISO 16063-21 as reference. After this, one notch filter equation is provided for the bending mode frequency using MATLAB®. It was used the DIAMOND software that owns the capability of the modal identification, allowing directly explore the effects of test conditions on the identified modal parameters.
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).
1999-10-06
Technical Paper
1999-01-3446
M. A. Ofsthun
Designing and producing a durable commercial airplane requires balancing good detail design and good manufacturing processes. Wings are fatigue sensitive structures and Boeing Commercial Airplanes Group (BCAG) relies on fatigue rated machine riveting for joining the skin to the stringer structure. This paper discusses how BCAG qualified the hand held low voltage electromagnetic riveting (HHLVEMR) process. Use of this process results in reduced fabrication flow time and fewer ergonomic type injuries, while maintaining the design requirements.
1999-10-19
Technical Paper
1999-01-5633
Dimitri N. Mavris, Danielle S. Soban, Matthew C. Largent
In today’s atmosphere of lower U.S. defense spending and reduced research budgets, determining how to allocate resources for research and design has become a critical and challenging task. In the area of aircraft design there are many promising technologies to be explored, yet limited funds with which to explore them. In addition, issues concerning uncertainty in technology readiness as well as the quantification of the impact of a technology (or combinations of technologies), are of key importance during the design process. The methodology presented in this paper details a comprehensive and structured process in which to explore the effects of technology for a given baseline aircraft. This process, called Technology Impact Forecasting (TIF), involves the creation of a forecasting environment for use in conjunction with defined technology scenarios. The advantages and limitations of the method will be discussed, as well its place in an overall methodology used for technology infusion.
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
1999-01-5594
Bjoern Diekjobst, Joern Goos
The paper deals with a structural optimization of the main wing structure of a 2nd generation supersonic commercial transport using the optimization tool STARS to determine a first pre-design. The optimization revealed drastic design changes in stiffness and mass distribution relative to the initial design estimation. Large parts of the forward wing are determined by minimum thickness while the largest cover thickness moved from inboard to far outboard on the rear wing. In addition sensitivity investigation on material allowables are carried out and showed that an increase of 10% of the design allowables of the CFRP material results in a reduction of about 5% total wing weight. In addition, investigation on the elastic behavior indicate the need for further provisions.
1999-10-19
Technical Paper
1999-01-5597
Bosko Rasuo
This paper presents the analysis of the survivability of a heavy transport helicopter tail rotor blade made of composite laminated materials after ballistic damage made by the bullet of 7.9 mm calibre shoulder weapons. Penetrating damages made in the root part of the tail rotor blade spar have been analyzed. The test program for the tail rotor helicopter blades has included dynamic testing nondamaged and damaged blades in full-scale. Based on the results of vibratory testing and fatigue testing an assessment is made about the vulnerability and the survivability of the helicopter tail rotor blade after ballistic damage made by the bullet of shoulder weapons.
1999-08-10
Technical Paper
1999-01-2982
John K. Schmidt, USN, Donald W. Lawson, USN, Brent W. Goodrum, USMC
In order to address a Naval Fleet Logistics Support (VR) Wing Commander’s request to proactively uncover safety factors in VR maintenance operations, a prototype climate survey was taken by VR Wing maintainers in 13 squadrons. Nearly 800 surveys were tabulated, and the results were analyzed using a model for high reliability organizations. Overall, the preliminary analysis of the survey data pointed out some potential areas in the VR Wing and each of its aircraft communities for intervention.
1999-08-10
Technical Paper
1999-01-2981
John K. Schmidt, USN, Robert C. Figlock, USMC, Curtis D. Teeters, USN
To study maintainer error, the Naval Safety Center’s Human Factors Accident Classification System (HFACS) was adapted for Maintenance Related Mishaps (MRMs). The HFACS Maintenance Extension (ME) successfully profiled the errors present Naval Aviation Class A MRMs. In order to assess its suitability for studying major and minor airline accidents, a post hoc analysis was conducted on 124 Naval Fleet Logistics Support (VR) Wing maintenance related mishap, hazard, and injury reports. Two judges separately coded the 124 VR Wing incidents; a Cohen’s kappa of .78 was achieved, indicating an “excellent” level of agreement. Generally, HFACS-ME was able to profile maintainer errors found in more minor incidents and the factors that contribute to them. Common factors observed include errors attributed to third party maintenance, inadequate supervision, failed communications, skill-based errors, and procedural violations.
1999-10-19
Technical Paper
1999-01-5570
Paul A. Eustace, Lloyd R. Jenkinson
This paper presents the results of four case studies of future fighter concepts incorporating new technologies. The introduction of advanced materials, enhanced agility and lower observability are individually assessed relative to an existing design (F-16). All these technologies are then integrated into a single design concept for final assessment. A newly developed mass prediction model (AMBER) [1] [2] has been used in these studies to estimate structural masses, centers of gravity and pitch inertia. The method employs idealized structural analysis to size the aircraft framework. This allows more accurate predictions in the aircraft conceptual design phase than existing statistically based methods and provides design insights into the aircraft configuration.
1999-10-19
Technical Paper
1999-01-5572
Terence J. Barnes
Mr. Barnes is the Federal Aviation Administration (FAA) Chief Scientific and Technical Advisor for Structural Loads and Design Criteria, and in this position he is responsible for recommending appropriate research to support his discipline. He recommended the establishment of the FAA Operational Loads Monitoring Program in 1988, (Reference 1) and continues to actively promote and monitor the research, and use of the results.
1999-10-19
Technical Paper
1999-01-5543
Charles Raab
Air Traffic Services (ATS) and Airline Operational Control (AOC) have developed independently as higher-level management functions to address separate, but related concerns of the Federal Aviation Administration (FAA) and the airlines, respectively. In today’s National Air Space (NAS), most interactions are limited to the results of unilateral decisions and communication of chosen options, with very little information about the objectives, constraints, processes, or rationale for those decisions being exchanged. However, the underlying philosophy of Air Traffic Management (ATM) and AOC is changing and the system is becoming much more collaborative. Increasingly, the military is beginning to be a key user in the overall NAS community, as well as in the global airspace community. As the concepts of free flight begin to emerge, military users will need to employ methods and technologies in use by commercial airspace users for both ground and air.
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