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Journal Article

ℒ1 Adaptive Flutter Suppression Control Strategy for Highly Flexible Structure

2013-09-17
2013-01-2263
The aim of this work is to apply an innovative adaptive ℒ1 techniques to control flutter phenomena affecting highly flexible wings and to evaluate the efficiency of this control algorithm and architecture by performing the following tasks: i) adaptation and analysis of an existing simplified nonlinear plunging/pitching 2D aeroelastic model accounting for structural nonlinearities and a quasi-steady aerodynamics capable of describing flutter and post-flutter limit cycle oscillations, ii) implement the ℒ1 adaptive control on the developed aeroelastic system to perform initial control testing and evaluate the sensitivity to system parameters, and iii) perform model validation and calibration by comparing the performance of the proposed control strategy with an adaptive back-stepping algorithm. The effectiveness and robustness of the ℒ1 adaptive control in flutter and post-flutter suppression is demonstrated.
Technical Paper

“Web-ACSYNT”: Conceptual-Level Aircraft Systems Analysis on the Internet

1997-10-01
975509
A Web-based version of the aircraft design program ACSYNT has been created. “Web-ACSYNT” provides the user with a familiar user interface and is accessible from multiple platforms. Analyses are based upon a set of baseline aircraft models which can be modified through a carefully selected set of parameters related to weight, aerodynamics, propulsion, economics, and mission. The software is intended to become one of the models that comprise the Aviation System Analysis Capability (ASAC) currently being developed by NASA under the Advanced Subsonic Technology (AST) program.
Technical Paper

“The Producers” New Row-Crop Tractors From John Deere

1982-02-01
821062
A line of five new row-crop tractors is being introduced by John Deere with innovative features including a 15-speed full power shift transmission, a high capacity, highly-maneuverable full-time mechanical front-wheel drive and micro-processor controlled instrumentation. In addition, the tractors have increased power, improved fuel economy, greater hydraulic power, improved hitch sensing, improved operator controls, lower sound levels, and revised styling. This paper documents the design and development of these new John Deere row-crop tractors.
Technical Paper

“The Creation, Development and Implementation of a Lean Systems Course at Oakland University, Rochester, MI”

2005-04-11
2005-01-1798
Countless articles and publications3,4,5 have documented and proven the efficacy, benefits and value of operating within a lean system. Furthermore, there exists common agreement amongst leading organizations successfully implementing a lean system that in order to do so it must take into consideration the entire enterprise, that is, from supplier to customer and everything in between6. One of the core issues this paper addresses is when the optimal time is to train and educate the people who currently have, or will have, influence over the ‘enterprise’.
Technical Paper

“RoHS” Compliant Chrome - Free Conversion Coating for Aerospace Manufacturing

2006-09-12
2006-01-3130
This paper presents, chemistry, test data and processing procedures on a non toxic and environmentally friendly chrome-free conversion coating alternative with the same level of adhesion and secondary corrosion resistance as that found in chrome containing conversion coating systems. Test data from military and independent sources will be presented on secondary coating adhesion, electrical conductivity, filiform and neutral salt-spray corrosion resistance as compared to chromate based systems .on magnesium, aluminum and zinc and their respective alloys. The European “RoSH” initiative will not allow for the presence of any hexavalent chromium on imported electrical components as of July first of 2006. Trivalent chromium based systems generate hexavalent chromium due to the oxidation of the trivalent chromium and as such will not be allowed.
Technical Paper

“Optimization” of Lower Deck Cargo Systems

1988-05-01
880973
The ability to carry cargo efficiently in passenger aircraft has influenced airline economics to the point that optimisation of the freight capacity is mandatory. This document discusses the alternative loading possibilities in defined Lover Deck Compartments and their doors to cater for current and future trends in ULD dimensions. As a result items for study centred on: 1) Optimisation of the available volumes Freight capacity resulting in the selection of “Pallets”-doors for both the Forward and AFT Compartments. Flexibility to meet Freight and Baggage requirements. Possible load arrangements to optimize aircraft C of G 2) Bulk Cargo Compartment Additional LD3 Container position in AFT/Bulk compartment to cater for an uneven number of Baggage container, allowing the carriage of an additional pallet. What is regarded as an optimum is presented.
Technical Paper

“Motion in FEA”: An Innovative Approach for More Physical and More Accurate Vehicle Dynamics Simulation

2012-04-16
2012-01-0762
Vehicle dynamics is a discipline of mechanical engineering that benefited of significant improvements thanks to the progress of computational engineering. Vehicle dynamics engineers are using CAE for the development of a vehicle with MBS and FEA. The concurrent use of these two technologies is a standard in the automotive industry. However the current simulation process is not fully efficient because local geometrical and material nonlinearities are not accurately modeled in classical MBS software. This paper introduces a methodology for vehicle dynamics simulation integrating MBS capabilities in one single nonlinear FEA environment enabling an accurate modeling of nonlinearity in vehicles.
Technical Paper

“MONOGAL”: A New Anti-Corrosion Material for the Automotive Industry

1982-02-01
820335
MONOGAL is a coated steel developped to improve the corrosion resistance of exposed automotive body applications. Its process os based on the brittleness of the η zinc coating in a range of temperatures below the melting point of the zinc. MONOGAL is produced on a hot dip galvanizing line; at the exit of the pot the free zinc is brushed off the light side of the differentially coated sheet. Side 1 of MONOGAL presents a very thin and continuous layer of iron-zinc diffusion alloy with no free zinc. Side 2 is a standard G90 or G60 zinc coating. The iron-zinc alloy layer has excellent anti-galling properties which improve the formability of MONOGAL over two side hot dip galvanized steel with the same r value. MONOGAL also shows good weldability, paintability and corrosion resistance.
Technical Paper

“Investigation of High Achievable Pollutant Reduction on a “State of the Art” Indian 2 Wheelers - Technology Road Map to a Cleaner Air”

2015-11-17
2015-32-0802
Affordable, efficient and durable catalytic converters for the two and three wheeler industry in developing countries are required to reduce vehicle emissions and to participate in a cleaner and healthier environment. As a contribution Continental Emitec started a comprehensive testing program with a state of the art 180 cc Bharat Stage (BS) III Indian motorcycle. The program consists of testing the state of the art of Metallic substrates with structured foils with various catalyst sizes and positions (original or close coupled). The publication presents a short literature survey and the results of the investigation with a big catalyst volume mounted in underfloor position as well as in close coupled position, gained over the World-wide harmonized Motorcycle Test Cycle, considering the two possible vehicle classifications of this motorcycle, Sub-Class 2.1 and Sub-Class 2.2.
Technical Paper

“Insert and Fly” Using PCMCIA PC Cards in the Avionics Market

1994-11-01
942553
When looking into using PCMCIA PC Cards in the avionics market, three areas must be researched. The first is what are the applications and benefits of using the PC Cards while in flight, followed by the applications and benefits on the ground, and thirdly on how to make a PC Card that would stand up to the rugged avionics environment. PCMCIA PC Cards can be used in all aspects of flight. Three possible applications on the ground are; paperless documentation, modifications, flightline changes. Once airborne, PC Cards can be removed and a different functionality card can be inserted. One PC card socket can be used for many different functions during one flight. Some of the possible applications for PC Cards inflight are; flight plan changes, backup Line Replaceable Units (LRUs), and solid state data collection.
Technical Paper

“Greater Than the Sum of its Parts” Integrated Flight Training/Aircrew Coordination

1994-10-01
942132
The requirement for crew resource management (CRM), or aircrew coordination training (ACT) in military parlance, has been well documented and attested to. In addition, aircraft systems training has become more intense and more in-depth in the new aircraft designs, especially in multi-crew and complex aircraft such as the MV-22 Osprey Tiltrotor. (see Figure 1) Former training systems detailed training procedures that called for classroom training and simulation/simulator training followed by flight training. Improvements in aircraft flight skills training provide increased flying training capability coupled with reduced training time by integrating a mixed simulation/flight training syllabus, e.g. two to three simulation periods followed by one or two flight training periods covering the same material/skills. In addition, the simulation training will introduce new skills; the following flight periods will further refine/hone those skills.
Technical Paper

“Fuel Flow Method2” for Estimating Aircraft Emissions

2006-08-30
2006-01-1987
In recent years there has been increasing interest in quantifying the emissions from aircraft in order to generate inventories of emissions for climate models, technology and scenario studies, and inventories of emissions for airline fleets typically presented in environmental reports. The preferred method for calculating aircraft engine emissions of NOx, HC, and CO is the proprietary “P3T3” method. This method relies on proprietary airplane and engine performance models along with proprietary engine emissions characterizations. In response and in order to provide a transparent method for calculating aircraft engine emissions non proprietary fuel flow based methods 1,2,3 have been developed. This paper presents derivation, updates, and clarifications of the fuel flow method methodology known as “Fuel Flow Method 2”.
Technical Paper

“DELRIN” ACETAL RESIN —a new engineering material

1959-01-01
590033
“DELRIN” is a new thermoplastic which offers high strength, excellent thermal stability, good fatigue life, low creep, and excellent solvent resistance. This paper describes the physical and chemical properties of the material, and the range of possible uses. The material is easily fabricated into complex shapes by standard injection-molding techniques. Also, it can be easily joined to itself or to other materials. The authors think that the material offers advantages over metals in its good fric-tional properties, abrasion resistance, and corrosion resistance.
Technical Paper

“CDaero” - A Parametric Aerodynamic Drag Prediction Tool

1998-02-23
980398
The objective of the development of the aerodynamic drag predictive tool CDaero was for use as a module for the Automobile Design Support System (AutoDSS). CDaero is an empirically based drag coefficient predictive tool based initially on the MIRA (Motor Industry Research Association) algorithm. The development philosophy was to be able to predict the aerodynamic drag coefficient of an automobile with knowledge of the features of the surface geometry control curves. These are the curves that control the 3-dimensional geometry as seen in the profile, plan and front and rear views. CDaero has been developed in a computing environment using the equation solver TKSolver™. Fifty-one input feature values are first determined from the automobile geometry and then entered into the program. CDaero models the drag coefficient with thirteen different components covering the basic body, as well as additional components such as the wheels, mud flaps, etc.
Technical Paper

“ACCU-DRIVE” STABILITY WITH COMFORT THE 1969 BUICK CHASSIS

1969-02-01
690490
Buick engineers are well pleased with their '69 Chassis. Benefits of a unique front suspension camber curve are documented. The effects of various suspension parameters on ride and handling are explained. These were varied independently of one another in the course of evaluating over 30 suspension configurations.
Technical Paper

¼ Scale VehicleWake Pattern Analysis using Near-Wall PIV

2006-04-03
2006-01-1027
3-D Flow separations such as those that occur on the rear end of a vehicle have an impact on wall pressure distribution, hence on aerodynamic forces. The identification of these phenomena can be made through the analysis of skin friction patterns, which consist of the “footprints” of flow separations. These can be determined from qualitative and quantitative data obtained from near-wall PIV measurements. The wake flow of different configurations of a simplified 1/4 scale car model are analyzed. The influence of the slant angle and the Reynolds number on 3-D separated flow patterns and their induced pressure distribution is addressed, based on near-wall PIV, standard PIV and wall pressure measurements. This enables to understand how a topological change (the size or shape of a separation pattern) modifies the associated pressure distribution (therefore the drag coefficient). Finally, insights into instantaneous topology identification are presented.
Technical Paper

the design of Planetary Gear Trains

1959-01-01
590059
THE usefulness of planetary gear trains and the engineering techniques necessary for optimum design are discussed in this paper. A simple method for calculating planetary gear ratios is described which can be used to determine quickly the potential usefulness of any planetary configurations. The author lists criteria which help to evaluate the potential of a planetary gear train schematic from the standpoints of gear noise and structural viewpoint. Detailed design of individual members include spacing of the pinions, mounting considerations, thrust direction, lubrication, and stress evaluation.
Technical Paper

some thoughts on optimum combinations of Wings and Vertical Thrust Generators in VTOL Aircraft

1959-01-01
590040
THIS PAPER reviews VTOL problems, indicating probable ways toward optimization of whole lifting and propelling system. Also discussed are the power and thrust requirements for optimum cruise and vertical take-offs and landings for propeller-driven and jet-propelled aircraft. Three speed ranges offer the most promise for VTOL aircraft, if thrust requirements for cruise and take-off are to match. The ranges are centered around Mach numbers of 0.65, 0.8, and 2.0+. There is a possibility of overcoming the high thrust needed for hovering by use of bypass augmentation, special hovering jets, or favorable ground effects, the author reports.
Technical Paper

selection of Optimum Modes of Control for aircraft engines

1959-01-01
590047
THE optimum mode of control for an aircraft engine is dependent on both the configuration of the engine and its application. Each engine application requires several detail modes of control, one for each definable regime of operation of the engine. Discussions of control requirements can be simplified by classifying these regimes by objectives: physical limiting, thrust, and transient control. The turbojet engine is the basis for the discussion in this paper. Acceptable modes of control can often be selected by inspection of the engine and its application. Selection of an “optimum” control mode requires investigation of the operation of the engine and weapons system at every stage of its use. The selection of a “mode” of control requires a compromise between performance and other design factors. The need for simplicity and accuracy must be balanced against the stability requirements. The availability and flexibility of control components may limit the modes of control considered.
Technical Paper

properties of Asbestos Reinforced Laminates at elevated temperatures

1960-01-01
600063
IF ROCKET OR MISSILE designers were asked to choose one specific property of engineering materials they would like to have improved, the largest percentage would undoubtedly select strength at high temperature. In addition to retaining strength at high temperatures, missile materials must be resistant to erosion and ablation. Missile structures must also be satisfactory when subjected to aerodynamic and acceleration loads, high stresses of vibration, and thermal shock. The need for low-density, easily fabricated, heat-resistant materials has resulted in a continuing search for more effective combinations of known materials, as well as the development of new materials. This paper discusses some interesting results obtained in studies of composite materials that might be used for rocket or missile construction.
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