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2017-10-31
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
2015-01-2487
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.
2015-09-15
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.
2015-04-14
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
2008-01-2259
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.
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.
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
2002-01-2918
Vitaliy Yu. Nezym
The presence of tip clearance between rotating blades and casing produces unfavorable influences upon compressor stage performances. Application of abradable linings (inserts) in the casing above rotating blades reduces this tip clearance to practically zero. And the variant is spread enough when rotor blade tips make an entire annular recess (EAR) of approximately rectangular configuration (RC) in the meridional section of casing (of lining). Some researches proved that the presence of entire annular recess in abradable lining may compensate somewhat the influence of tip clearance between blade tips and casing baseline. Therefore it is possible to substitute abradable linings for entire annular recess of rectangular configuration specially manufactured in the casing.
2002-11-05
Technical Paper
2002-01-2924
Robert N. McGrath
This paper summarizes several years of research which considered the National Aeronautics and Space Administration's assertion that the Small Aircraft Transportation System (SATS) will be an economical alternative to automobile and airline travel, when considering the value of travelers' time. Performance was studied in the corporate aviation environment, using NASA's metric for cost effectiveness. Cost, cost effectiveness, and the sensitivity of cost effectiveness to key independent variables were examined. Analyses shed favorable light on NASA's premise.
2002-11-05
Technical Paper
2002-01-2923
David Berry
Aerospace engineers continually strive to identify materials which provide processing flexibility, reduce manufacturing costs, and prove durable in harsh environments. PEEK™ polymer, successfully displaces metals, traditional composites, and other plastics in a growing number of aerospace applications due to its exceptional properties and ability to be easily fabricated into high tolerance parts through multiple manufacturing techniques.
2002-11-05
Technical Paper
2002-01-2922
Thierry Miquel, Félix Mora-Camino
This paper proposes an analysis and comparison study between two different nonlinear control approaches to design a relative guidance mode for civil aircraft. The first investigated approach is based on feedback linearizing control, whereas the second investigated approach is based on optimal control. These two approaches are compared in terms of performances and complexity, including trajectory characteristics and communication requirements. It appears that both approaches are quite promising and deserve extensive studies for further refinement and validation.
2002-11-05
Technical Paper
2002-01-2929
Simon I. Briceño, Dimitri N. Mavris
Recent market studies indicate a renewed interest for a quiet Supersonic Business Jet (SBJ). The success of such a program will be strongly dependent upon the achievement of stringent engine noise, emissions and fuel consumption goals. This paper demonstrates the use of advanced design methods to develop a parametric design space exploration environment which will be ultimately used for the identification of an engine concept capable of satisfying acoustic levels imposed by FAR part 36 (stage IV) and NOx and CO2 standards as stated in the 1996 ICAO. The engine performance is modeled through the use of Response Surface and Design of Experiments Techniques, enabling the designer/decision-maker to change initial engine parameter values to detect the effects of the responses in a time efficient manner. Engine performance and engine weight results are obtained through physics-based engine analysis codes developed by NASA.
2002-11-05
Technical Paper
2002-01-2928
Mohsiul Alam
The AS900 is a 7,000-lbf-thrust class medium bypass turbofan for business jet and small regional transport aircraft. During initial development testing, high non-synchronous vibration (NSV) limited AS900 engine operation in the test cells. The NSV was associated with a substantial aft end motion involving both spools, the static structure, and the aft mount system. The aft mount was modified, which allowed the engine to run at its maximum power with a moderate level of NSV. However, the presence of NSV was perceived to be a customer satisfaction issue as a potential exciter of cabin noise in the aircraft. Therefore, a comprehensive analysis and test program was initiated to eliminate NSV from the AS900 engine. This paper presents the process of identifying the root cause of the NSV and its influencing factors, as well as the design changes to successfully eliminate it from the AS900 engine.
2002-11-05
Technical Paper
2002-01-2927
Ismael Fernández, Adam R. Krause, Dimitri N. Mavris
The success of business jets like the Citation X, the fastest civil aircraft in use after the Concorde, highlights the need for speed to improve business and globalization. Currently, developing a supersonic business jet has many technical and economical impediments. These obstacles include sonic boom, emissions and noise requirements problems that are easily meet or do not exist for subsonic aircraft. A baseline aircraft, defined by an optimization process, is the starting point for this study. However, this baseline aircraft does not meet the sonic boom, emissions and noise requirements, which are very strict. Companion studies to this one indicate that it may be possible to meet emissions and noise requirements, but it is clear that technology infusion is necessary for the future viability of this aircraft concept to succeed.
2002-11-05
Technical Paper
2002-01-2939
Francois Gau
Aircraft are aging. Wiring on aircraft is mostly inspected visually with little emphasis on non-destructive testing. Current “on-condition” practices are time consuming, costly and subject to human factors. Wiring should to be considered as a system on the aircraft and analyzed on a proactive basis, similar to the engines and the structure. New technologies are available to enable a wire integrity program.
2002-11-05
Technical Paper
2002-01-2931
Hampus Gavel
As the time between different development projects of new aircraft (a/c) extends, experienced personnel in the field of basic a/c system design are difficult to employ when being on the onset of a new design. Further on basic a/c system design is a field neglected in literature and in the educational system. A text is under development that summarizes the Saab experience of the complete fuel system design with respect to the fighter a/c Viggen and Gripen, the commuter a/c 340 and 2000, the trainer a/c SK60 and also the conceptual a/c B3LA. This paper is an extract of this text and describe early considerations that have to be made when designing a fuel transfer system. Emphasis is put on the top requirements on a/c level.
2002-11-05
Technical Paper
2002-01-2930
Michael Buonanno, Choongiap Lim, Dimitri N. Mavris
Market forecasts predict a potentially large market for a Quiet Supersonic Business Jet provided that several technical hurdles are overcome prior to fielding such a vehicle. In order to be economically viable, the QSJ must be able to fly at supersonic speeds overland and operate from regional airports in addition to meeting government noise and emission requirements. As a result of these conflicting constraints on the design, the process of selecting a configuration for low sonic boom is a difficult one. Response Surface Methodology along with physics-based analysis tools were used to create an environment in which the sonic boom can be studied as a function of design and mission parameters. Ten disciplinary codes were linked with a sizing and synthesis code by using a commercial wrapper in order to calculate the required responses with the desired level of fidelity.
2002-11-05
Technical Paper
2002-01-2944
Philip R. Kedrowski, Robert E. Wahl, Edward D. Clark
Over the past 20 years, gas turbine engine simulators have evolved into an integral tool for testing and certifying the electronic controllers of gas turbine engines. At Honeywell, this evolution has taken place on parallel paths. Namely, the simulators for testing the Auxiliary Power Unit (APU) controllers and the simulators for testing the propulsion engine controllers. Although at the same company, these paths implemented two unique approaches in their development. However, the underlying philosophy behind how these simulators are used is the same and unique to Honeywell. This work outlines these evolutionary approaches and gives light to Honeywell's successful approach to simulator design and implementation. In the early years, simulators were built solely as a tool for use in testing the hardware interface of the controllers and didn't significantly reduce the time performing tests on development engines.
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
2002-01-2942
Gordon J. J. Bartley, Andy M. Anderson, Kenneth B. Jones
Cabin air quality is of continuing importance [1]. Contamination of air with particulates or vapors has the potential of affecting the health of passengers and flight crew. Therefore, measures are required to maintain acceptable levels of cabin air quality. One potential source of cabin air contamination is lubricating oils used in the engines. Type II oils are required for the main engines, but Type I or Type II oils can be used for the APU, with Type I recommended by some engine manufacturers for its cold-start properties. Southwest Research Institutes (SwRI®) Department of Emissions Research used an internally developed analytical method called Direct Filter Injection/Gas Chromatograph (DFI/GC™) to analyze for volatile fractions of lubricating oil contaminants on Environmental Control System (ECS) components. Samples of two standard Type II aviation turbine lubricating oils were analyzed with the DFI/GC™ method and their spectra examined.
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