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2017-10-25
White Paper
WP-0002
The environmental impact of hydrocarbon-burning aircraft, both from the perspective of gas emissions and that of noise, is one of the main motivations for the move to electric propulsion. The added benefit from this shift to electric propulsion is that it has resulted in lowering the costs of electrical components such as motors, power electronic (PE) circuits, and batteries that are essential to this technology. This white paper seeks to explore the history, architecture, electrical components, and future trends of electric flight technology.
2017-09-04
Technical Paper
2017-24-0120
Matthew Keenan
Abstract The earliest public domain reference regarding full engine testing of an automotive catalyst was from January 1959, written by GM and presented at the annual SAE meeting in Detroit. This current publication will review the first public domain paper referencing different aftertreatment technologies (such as TWC, LNT, DPF and SCR, but not limited to these technologies) and compare the technologies to the current state of the art in aftertreatment technology. This historical review using a range of databases, will show how exhaust aftertreatment technologies have significantly enhanced emissions control over the last 60 years for both gasoline and diesel applications. A timeline will be given showing when various technologies were first presented into the public domain. This will indicate how long it has taken certain emissions control technologies to enter the market.
2017-03-28
Technical Paper
2017-01-1484
Giampiero Mastinu, Mario Pennati, Massimiliano Gobbi, Giorgio Previati, Federico Ballo
Abstract The ride comfort of three Alfa Romeo cars, namely Giulietta (1955), Alfetta (1972) and 159 (2005) has been assessed both objectively and subjectively. The three cars belong to the same market segment. The aim is to let young engineers or graduate students understand how technology has evolved and eventually learn a lesson from the assessed trend. A number of cleats have been fixed at the ground and the three cars have traversed such uneven surface. The objective assessment of the ride comfort has been performed by means of accelerometers fixed at the seat rails, additionally a special dummy developed at Politecnico di Milano has been employed. The subjective assessment has been performed by a panel of passengers. The match between objective and subjective ratings is very good. Simple mathematical models have been employed to establish a (successful) comparison between experimental and computational results. The ride comfort differs substantially among the cars.
2016-04-05
Technical Paper
2016-01-0177
Edward G. Groff
During the late 1980’s and early 1990’s the two-stroke-cycle engine was an extremely popular and highly publicized automotive powertrain technology globally. Active development programs existed at many OEMs during that period, including GM, where the author was involved, and production seemed eminent. Autoweek stated on the cover of its March 12, 1990 issue, “Revolution for the millennium or Wankel of the ‘90s?” This paper covers the new technologies that led to the generation of so much excitement in the industry and press, the advantages and disadvantages of the engine concept, R&D tools developed at that time that are still in use today, and various engine concepts pursued in the industry. The story is not only interesting from engineering and technology perspectives but illustrates how innovations in certain subsystems become enablers to revive a system technology by eliminating issues that prevented it from making it to production in the past.
2016-04-05
Technical Paper
2016-01-0176
Joseph M. Colucci
Abstract This paper summarizes the history and most significant accomplishments of the GMR-GMR&D Fuels and Lubricants Department from its predecessor organization starting about 100 years ago to its demise during a reorganization in the late 1990s. It covers: Combustion research to improve engine efficiency and reduce emissions, Development of chemical, bench, engine, and vehicle tests to improve fuel and lubricant quality, Development of technology to reduce vehicle emissions, Research to understand and reduce air pollution, and Evaluation of alternative fuels and lubricants. In total, the above activities helped not only GM and the worldwide auto industry, but also society. They improved the operation of vehicles and the quality of the air in the United States and around the globe, favorably affecting the lives of hundreds of millions of people. They also created the recognition of and the reputation of the Fuels and Lubricants Department as the best of its kind in the world.
2016-04-05
Technical Paper
2016-01-0175
Edward G. Groff
Abstract Spark-ignition direct-injection technology existed since about 1930 for the primary purpose to give multifuel capability over what the compression-ignited diesel engine could provide. In subsequent decades development of multifuel engines continued both as higher-compression-ratio “spark-ignited diesel” and moderate-compressionratio stratified-charge engines. Global events in the 1960-1970’s, namely the oil embargo, oil-supply crises, and the passage of the U.S. Clean Air Act intensified interest in such engines. The military and large commercial fleet operators were particularly focused on efficiency and multifuel capability over concerns for fuel supplies. Automobile manufacturers were focused on gasoline-fueled efficiency and the potential to reduce engine-out legislated NOx emissions with the stratified-charged combustion systems.
2016-04-05
Technical Paper
2016-01-1497
William Bortles, Wayne Biever, Neal Carter, Connor Smith
Abstract This paper presents a comprehensive literature review of original equipment event data recorders (EDR) installed in passenger vehicles, as well as a summary of results from the instrumented validation studies. The authors compiled 187 peer-reviewed studies, textbooks, legal opinions, governmental rulemaking policies, industry publications and presentations pertaining to event data recorders. Of the 187 total references, there were 64 that contained testing data. The authors conducted a validation analysis using data from 27 papers that presented both the EDR and corresponding independent instrumentation values for: Vehicle velocity change (ΔV) Pre-Crash vehicle speed The combined results from these studies highlight unique observations of EDR system testing and demonstrate the observed performance of original equipment event data recorders in passenger vehicles.
2015-09-15
Journal Article
2015-01-2581.01
Paul Dees, Scott Eberhardt
The original paper published mistakenly did not include Paul Dees, Boeing in the author listing.
2015-09-15
Technical Paper
2015-01-2580
David Lednicer
Abstract During the 1930s and 1940s, aircraft designers worked on developing novel design features. Some of these features worked and are commonplace today. Other features fell by the wayside and have been forgotten. These novel design features include laminar flow wings, low-drag cooling systems, buried propulsion systems, canard configurations, jet engines, break-away wing tips, pressure cabins and swept wings. The development and applications of these features will be examined. Specific technical details of these applications will be included in this examination. For the design features that fell by the wayside, the reasons for this outcome will be discussed
2015-09-15
Journal Article
2015-01-2581
Scott Eberhardt
Abstract World War 1 began with the airplane as a frail, unarmed means of observing enemy troop movements and ended with the airplane as a powerful, much more evolved weapon of war. There were specialized roles for fighter, bomber and ground attack aircraft as well as newly developed aerial strategies and tactics for operational effectiveness. Many aircraft design technologies greatly matured during the war. Four will be the subject of this paper: Drag reduction, aircraft handling qualities, stability and control, airfoil design technology, and structures design technology. Propulsion and armament also matured greatly but are not discussed in the paper. The discussion of drag reduction will illustrate the innovations of the British on external wire bracing drag, the French on cowl design and the Germans on cantilevered wings and induced drag.
2015-09-15
Technical Paper
2015-01-2487
Dara Childs
Abstract Rotordynamics developed from the beginning of the 20th century to deal with problems associated with steam turbines. This paper deals with intense developments starting around 1975 through 2000 in rotordynamics to deal with new, larger machines running at higher speeds and higher power levels. Most of the new problems of interest dealt with subsynchronous instabilities. Issues associated with “synchromnously unstable” motion due to the Morton Effect is also reviewed.
2015-04-14
Technical Paper
2015-01-0416
Howard Evans
Abstract This paper summarises the history of Rochdale Motor Panels and Engineering Ltd. (RMP), established in England after the Second World War, from its origins as a small car-repair business though to the manufacture of sports coupés utilising an innovative glass-fibre monocoque construction. The political climate which caused RMP and similar undertakings to develop and flourish in the 1950s and 60s is explained together with details of the three men who had the defining influence on the cars that were created. Products, including aluminium-bodied cars, produced primarily for racing, are described, leading into the introduction of glass-fibre construction which enabled a profitable transition into higher volume body and chassis manufacture, and ultimately completely assembled cars.
2015-04-14
Technical Paper
2015-01-0972
Alexander Pawlowski, Derek Splitter
Abstract It is well known that spark ignited engine performance and efficiency is closely coupled to fuel octane number. The present work combines historical and recent trends in spark ignition engines to build a database of engine design, performance, and fuel octane requirements over the past 80 years. The database consists of engine compression ratio, required fuel octane number, peak mean effective pressure, specific output, and combined unadjusted fuel economy for passenger vehicles and light trucks. Recent trends in engine performance, efficiency, and fuel octane number requirement were used to develop correlations of fuel octane number utilization, performance, specific output. The results show that historically, engine compression ratio and specific output have been strongly coupled to fuel octane number.
2008-08-19
Journal Article
2008-01-2258
Melinda Laubach
Due to current economic conditions, aircraft companies of today are experiencing an increasing need for their fleets to maintain safe operation beyond their original design life. The result is a growing percentage of aging aircraft that must maintain their airworthiness by utilizing standard methods of inspection and repair. In order to determine if potential continuing airworthiness problems exist for the general aviation fleet as a function of the aging process, the Federal Aviation Administration (FAA) established a research program at the National Institute for Aviation Research (NIAR), Wichita State University, to conduct destructive evaluations on four aged general aviation airplanes. The intent of the program is to provide insight into the condition of a typical aged airplane and to see if a correlation exists between its maintenance history and current condition from a safety of flight perspective.
2008-08-19
Journal Article
2008-01-2259
K. S. Raju, B. L. Smith, F. Caido, C. Gomez, M. Shiao
The fatigue behavior of Hilok fastener joints under constant amplitude loading has been investigated experimentally. The effects of load transfer in an unbalanced joint configuration was characterized in terms of a stress severity factor relative to the open-hole configuration. The experimental data indicates that the clamp-up forces dominate the performance of fastener joints with the open-hole fatigue life being the lower bound at the stress levels investigated. The failure modes were observed to transition from a net-section type failure across the minimum section to a fretting induced failure at some distance from the hole. The experimental data has been used to develop stress severity factors to be used as a measure of the fatigue quality of the fastener joints.
2005-10-03
Technical Paper
2005-01-3195
Michael J. Pryce, Chris Farara, Michael J. Hirschberg
Since its inception in 1957, the P.1127/Harrier family of aircraft has been produced in a diverse range of variants, from the original ground attack fighter to the naval Sea Harrier and on to the trans-Atlantic Harrier II series. These developments testify to the adaptability of the basic design, but behind the scenes a large number of other versions were projected over the years. This paper will look at those variants that were studied by the original designers of the Harrier family in Hawker Aircraft/Hawker Siddeley/British Aerospace. It will also touch upon variants that were jointly studied within the US/UK partnership with McDonnell Douglas/Boeing that produced the Harrier II, but a later paper on US aircraft will cover those versions that were predominantly US designed.
2004-04-20
Technical Paper
2004-01-1800
Harry R. Clements
The U.S. heartland city of Wichita has long been known initially, of course, as a cowtown but then as a hotbed of rock solid aviation, especially - but not solely - General Aviation. But few would associate it with either far out aeronautical research or, even less, international intrigue. Yet at just about the midpoint of the first century of flight it was the focal point for researchers from two sometime military adversaries of the U.S. to join with locals to perfect a system of lift enhancement that demonstrated performance measures never achieved before or, in practice, since. The routes that those foreign-born researchers took to get to Wichita provide a story as fascinating as the research itself. (Paper clips were an accommodating feature of relocation.)
2002-11-05
Technical Paper
2002-01-2945
Kevin D. Cluff, Joseph A. Scalise
This paper details the evaluation and implementation of Honeywell's End Item Temperature Test (EITT) process which functionally tests each production LRU at the customer-required temperature extremes. An aircraft system that formerly utilized 100% screening of electronic parts was selected for this process. A fixture was developed to allow the end item to be thoroughly tested while inside an environmental chamber. Using EITT, Honeywell replaced screening with EITT for specifically selected parts. The EITT adds thermal testing in addition to the normal environmental stress screening and acceptance test procedure steps. EITT also provides an effective tool for root cause failure analysis. The EITT-produced units (LRUs) were found to have 47% fewer IC removals than the previously built systems that were subjected to the 100% part screening. By reducing the part screening-caused damage, a 42% reduction was observed in mechanical damage such as bent leads.
2002-11-05
Technical Paper
2002-01-2949
James R. Phillips
A dynamical model of tire longitudinal slip, suitable for use in aircraft brake control system and antiskid design, is presented. The model differs from conventional mu–slip models in that it incorporates a single degree of freedom for tire stretch. Applications of the model in simulation, control synthesis, and stability analyses are described.
2002-11-05
Technical Paper
2002-01-3007
Michael Papadakis, Hsiung-Wei Yeong, Reuben Chandrasekharan, Mike Hinson
Experimental studies were conducted to investigate the effect of tailplane icing on the aerodynamic characteristics of 15%-scale business jet aircraft. The simulated ice shapes selected for the experimental investigation included 9-min and 22.5-min smooth and rough LEWICE ice shapes and spoiler ice shapes. The height of the spoilers was sized to match the horns of the LEWICE shapes on the suction side of the horizontal tail. Tests were also conducted to investigate aerodynamic performance degradation due to ice roughness which was simulated with sandpaper. Six component force and moment measurements, elevator hinge moments, surface pressures, and boundary layer velocity profiles were obtained for a range of test conditions. Test conditions included AOA sweeps for Reynolds number in the range of 0.7 based on tail mean aerodynamic chord and elevator deflections in the range of -15 to +15 degrees.
2002-11-05
Technical Paper
2002-01-3008
Lisa E. Jones
NASA's Aviation Safety Program was developed in response to the federal government's goal to reduce the fatal accident rate for aviation by 80% within 10 years. Accident Mitigation is a primary element of the Aviation Safety Program. The overall Accident Mitigation goal is to provide technology to the air transport industry to enable a decrease in the rate of fatalities and injury from crash loads and from in-flight and post-crash explosion and/or fire. Accident Mitigation is divided into two main elements - Fire Prevention and Systems Approach to Crashworthiness. The Systems Approach to Crashworthiness goal is to develop and promote technology that will increase the human survival rate or reduce the fatality rate in survivable accidents. The technical background and planning, selected technical activities, and summary of future efforts in the Systems Approach to Crashworthiness will be presented in this paper.
2002-11-05
Technical Paper
2002-01-3023
Al Creque
This paper will cover the significant technical advancements introduced to the Engine Alliance GP7200 turbofan engine that will power the new Airbus A380 commercial aircraft. The derivation of the engine from GE and Pratt & Whitney engine experience and the benefits of GP7200 engine architecture will be discussed.
2002-11-05
Technical Paper
2002-01-3013
D. Humphrey, W. Shawlee, P. Sandborn, D. Lorenson
How a system ages is central to the assessment of the effective utilization life of the system. Utilization life represents more than estimating the remaining life in an aged system, it is determining how to optimally plan a system's future management and future use to minimize the life cycle cost incurred. The consideration of utilization life of a system includes the physics of aging, damage accumulation techniques, mitigation of aging, qualified use of aged parts for spare replenishment, prognostics, and quantification of cost avoidance. Any approach to evaluating utilization life depends on a making an effective evaluation of the reliability, durability and safety of the system. Traditional Mean Time Between Failure (MTBF) metrics that assume a constant failure rate are likely to be less useful in the evaluation and practical implementation of utilization life concepts than Failure Free Operating Period (FFOP).
2002-11-05
Technical Paper
2002-01-3012
P. Singh, P. Sandborn, D. Lorenson, T. Geiser
Many electronic parts have life cycles that are shorter than the life cycle of the product they are in. Life cycle mismatches caused by the obsolescence of electronic parts can result in significantly sustainment costs for long life systems. In particular, avionics often encounters part obsolescence problems before being fielded and nearly always experience part obsolescence problems during their field life. This paper presents a methodology for determining the optimum design refresh (redesign) schedule for long field life electronic systems based on forecasted electronic part obsolescence and a mix of obsolescence mitigation approaches ranging from lifetime buys to part substitution.
2002-11-05
Technical Paper
2002-01-2998
Sami Movsesian
In the wake of the 9/11/2001 hijacking events, the Federal Aviation Administration (FAA) has emphasized the need for enhanced flight deck doors on commercial airplanes. The paper describes enhanced flight deck door, which meets the new FAA requirements for intrusion resistance and ballistic protection. In addition, the new door meets the existing requirements for rapid decompression, flight crew security and rescue.
2002-11-05
Technical Paper
2002-01-2997
Ikuo Kumakura, Masakatsu Minegishi, Kazuo Iwasaki, Hirokazu Shoji, Norio Yoshimoto, Hiroyuki Terada, Hirofumi Sashikuma, Akira Isoe, Toshihiro Yamaoka, Noriaki Katayama, Toru Hayashi, Tetsuya Akaso
The Structures and Materials Research Center of the National Aerospace Laboratory of Japan (NAL) conducted a vertical drop test of a fuselage section from a NAMC YS-11 transport airplane in December2001. This test program is a part of research activities in NAL on the structural crashworthiness of transport aircraft. In addition a cooperative research related to this test program was carried out between NAL and Kawasaki Heavy Industries, Ltd.(KHI). The main objective of this program is to develop optimal numerical models for crash simulation of aircraft fuselage and to obtain background data by drop tests of small-scale structural models and a full-scale fuselage section. Prior to the drop test of a full-scale fuselage structure, a trial numerical simulation on the crash behavior of a small-scale sub-floor structure was conducted by NAL using the explicit, nonlinear dynamic analysis code, LS-DYNA3D.
2002-11-05
Technical Paper
2002-01-3004
Richard G. Rateick, Kerri C. McCool, Eric C. Leonard, Joseph H. Hoeffer
The application of metastable beta titanium alloy Beta-C™ (Ti-3Al-8V-6Cr-4Mo-4Zr) in spring applications is increasing. A Ti-3Al-8V-6Cr-4Mo-4Zr, or more simply Ti-38-6-44, coil spring can be comparatively smaller than the steel mechanical equivalent on account of its high strength and lower shear modulus. This paper reviews the testing methods and results of load-life fatigue tests performed on helical compression springs at 177 °C with a stress ratio of R=0.456. All springs were compliance tested prior to fatigue testing as a means of measuring the shear modulus. To support spring behavior modeling, the shear modulus was also determined using a torsionally loaded strain gauged specimen tested at room temperature and 177 °C. The thermal expansion behavior was studied from room temperature to above 177 °C.
2002-11-05
Technical Paper
2002-01-2995
Allan Abramowitz, Timothy G. Smith, Tong Vu, John R. Zvanya
A 10-foot-long fuselage section from a Boeing 737-100 airplane was dropped from a height of 14 feet generating a final impact velocity of 30 feet per second. The fuselage section was configured to simulate the load density at the maximum takeoff weight condition. The final weight of 8870 pounds included cabin seats, dummy occupants, overhead stowage bins with contents, and cargo compartment luggage. The fuselage section was instrumented with strain gages, accelerometers, and high-speed cameras. The fuselage sustained severe deformation of the cargo compartment. The luggage influenced the manner in which the fuselage crushed, affecting the gravitational (g) forces experienced by the test section. The seat tracks experienced 15 g's vertical deceleration. Although numerous fuselage structural members fractured during the test, a habitable environment was maintained for the occupants, and the impact was considered survivable.
2002-11-05
Technical Paper
2002-01-3006
David C. Foyle, Becky L. Hooey, John R. Wilson, Walter A. Johnson
This study investigated pilots' taxi performance, situation awareness and workload while taxiing with three different head-up display (HUD) symbology formats: Command-guidance, Situation-guidance and Hybrid. Command-guidance symbology provided the pilot with required control inputs to maintain centerline position; Situation-guidance symbology provided conformal, scene-linked navigation information; while the Hybrid symbology combined elements of both symbologies. Taxi speed, centerline tracking accuracy, workload and situation awareness were assessed. Taxi speed, centerline accuracy, and situation awareness were highest and workload lowest with Situation-guidance and Hybrid symbologies. These results are thought to be due to cognitive tunneling induced by the Command-guidance symbology. The conformal route information of the Situation-guidance and Hybrid HUD formats provided a common reference with the environment, which may have supported better distribution of attention.
2002-11-05
Technical Paper
2002-01-3000
Douglas W. Akers, Scott J. Ritchie
A new patented technology, Photon Induced Positron Annihilation (PIPA) has been developed that provides the capability to nondestructively detect fatigue, corrosion induced fatigue, radiation and embrittlement damage at < 1% of fatigue life. Further, PIPA can accurately assess defect levels and predict the remaining life of various metallic, composite, and polymeric materials. PIPA has demonstrated the capability to detect damage in 2nd layer materials, without disassembly. PIPA is insensitive to surface geometries and anomalies such as paint or rust. Because PIPA detects fatigue and embrittlement at the atomic level, the PIPA process is directly applicable to detecting the fatigue and manufacturing defect issues pertinent to composite and metallic alloy components used in the aerospace industry.
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