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Journal Article

Research on Measurement Method of Road Gradient and Altitude by On-Road Driving

2009-04-20
2009-01-1116
Exhaust emissions from a vehicle under road driving condition is affected by the control state of ECU (Engine Control Unit). This control state highly depends on the driving force of the vehicle. The driving force is nearly equal to the driving resistance, which is the sum of the acceleration resistance, the air resistance, the rolling resistance and the gradient resistance. Although it is essential to take an accurate measurement of the road gradient, it is quite difficult to evaluate the gradient resistance in testing on-road driving. In this study, the measurement methods of the road gradient and the altitude with GPS, gyro sensor and height sensor are reported. The road gradient under the on-road driving condition is evaluated by the combination of measuring the pitch angle with the gyro sensor and measuring the vehicle gradient with the two height sensors. Verifying of this method, the altitude of the driving test route is also evaluated.
Technical Paper

Tribological Evaluation of the Aviation Kerosene for Use in CI Engines

2009-11-02
2009-01-2804
To reduce the fuel related logistic burden, NATO Armed Forces are advancing the use of a single fuel for both aircraft and ground equipment. To this end, F-34 is replacing distillate diesel fuel in many applications. Yet, unacceptable wear due to poor lubricity was illustrated by tests conducted with kerosene on High Frequency Reciprocating Rig. Therefore, HFRR tests were performed with fatty acid methyl esters of sunflower, palm, cotton-seed, tobacco-seed, olive, rape-seed and used frying oils, at volume concentrations from 0.05% to 0.6%. This study showed that the biodiesels used, produced a significant decrease in the wear scar diameter at concentrations of 0.2% to 0.4 %. Biodiesels derived from non-polyunsaturated oils, such as palm and olive gave better lubrication at certain concentrations.
Journal Article

Flying Test Bed Performance Testing of High-Bypass-Ratio Turbofans

2009-11-10
2009-01-3133
The commercial turbofan trend of increasing bypass ratio and decreasing fan pressure ratio has seen its latest market entry in Pratt & Whitney's PurePower™ product line, which will power regional aircraft for the Bombardier and Mitsubishi corporations, starting in 2013. The high-bypass-ratio, low-fan-pressure-ratio trend, which is aimed at diminishing noise while increasing propulsive efficiency, combines with contemporary business factors including the escalating cost of testing and limited availability of simulated altitude test sites to pose formidable challenges for engine certification and performance validation. Most fundamentally, high bypass ratio and low fan pressure ratio drive increased gross-to-net thrust ratio and decreased fan temperature rise, magnifying by a factor of two or more the sensitivity of in-flight thrust and low spool efficiency to errors of measurement and assumption, i.e., physical modeling.
Technical Paper

Improved Titanium Machining: Modeling and Analysis of 5-Axis Tool Paths via Physics-Based Methods

2009-11-10
2009-01-3131
Manufacturing of monolithic aerospace components entails development of complicated 5-axis tool paths containing thousands of lines of code and dozens of tool changes for milling and drilling operations. In-cut machining cycle times of 50-100 hours are common. Achieving meaningful reduction of cycle time while maintaining part quality is predicated upon the ability to model the physics of the machining operations. A methodology to predict forces used for analyzing large, complicated 5-axis tool paths for aerospace component machining is presented. The ability to accurately model length scales from the chip load (∼100 microns), part thickness (∼2mm), depths of cut (∼10mm) to part dimensions (∼10m) is provided. Forces and temperatures are predicted over the entire tool path using analytical and numerical techniques to extend an empirical database to generalized cutting conditions.
Technical Paper

Integration of Machining and Inspection in Aerospace Manufacturing

2009-11-10
2009-01-3130
The main challenge for aerospace manufacturers today is to develop the ability to produce high-quality products on a consistent basis as quickly as possible and at the lowest-possible cost. At the same time, rising material prices are making the cost of scrap higher than ever so making it more important to minimise waste. Proper inspection and quality control methods are no longer a luxury; they are an essential part of every manufacturing operation that wants to grow and be successful. However, simply bolting on some quality control procedures to the existing manufacturing processes is not enough. Inspection must be fully-integrated with manufacturing for the investment to really produce significant improvements.
Journal Article

Compact Fixturing Based on Magneto-rheological Fluids for Aeronautic Stringers Milling

2009-11-10
2009-01-3132
The paper explains the compact fixturing based on magneto-rheological (MR) fluids that have been designed and validated for aeronautic stringers milling. The MR fluid based tooling developed is flexible and reconfigurable as it can be adapted to different profile's lengths and sections and it is able to fix compliant workpieces without reference faces as the MR fluid adapts to the outer shape of each profile. The MR fluid based tooling is suitable to hold non-magnetic materials such as aluminum and also materials that do not admit high clamping forces, such as titanium, because they will appear as deformation after machining due to the memory effect of titanium. The MR fluid based tooling has been tested in a machine environment under real machining conditions and promising results have been obtained.
Technical Paper

A Flexible Wing Unmanned Aerial Research System

2009-11-10
2009-01-3127
CIRA is currently designing an Unmanned Aerial Research System, featuring high structural flexibility and light weight, code named HAPD. The project is framed within the Italian Aerospace Research Program, under the “UAV” Chapter. This UAS is mainly aimed at developing and validating advanced modeling methodologies for flexible aircrafts, where structural natural frequencies may overlap with flight dynamics frequencies. This peculiar condition challenges the command and control logics, as it requires an accurate modeling of the elastic behavior of the aircraft together with an actuation policy able to guarantee that maneuvering will not result in structural modes excitation. The vehicle will be given both remote piloting functions, either fully direct or mediated by a stability and control augmentation system, and fully autonomous flight capabilities.
Technical Paper

Control and Simulation of a Ducted Fan VTOL UAV

2009-11-10
2009-01-3126
This paper describes a strategy to simulate a dynamic model of a vertical takeoff and landing (VTOL) unmanned aerial vehicle (UAV) in flight transition from vertical climb to horizontal flight. Based on unique aerodynamic characteristics from CFD calculation and theoretical method the flight dynamics of ducted fan UAV is able to be modeled and simulated accurately. MATLAB/Simulink V-Realm Builder is a design and modeling software tool for air vehicles that is capable of modeling the performance and flight dynamics during the conceptual and preliminary stage of aircraft design. To develop a control strategy, modeling and simulation of flight dynamics of ducted fan UAV is necessary, because it not only can be applied to optimize dynamic model, but also be used to ensure the dynamic model match with control law.
Technical Paper

UAV Operation, Crash Analysis, and Measurement of Particle Concentrations above a Forest and Surrounding Farmland

2009-11-10
2009-01-3129
The Nucleation In ForesTs (NIFTY) campaign was conducted in the Morgan Monroe State Forest (MMSF) during the month of May 2008. The objectives of this campaign were to understand the principal mechanisms of nucleation, the limitations of nucleation and growth, the spatial extent of nucleation events, subsequent particle growth after nucleation in MMSF, and the link between particle nucleation and breakdown of the nocturnal boundary layer which enhances vertical mixing. This paper discusses the use of a UAV to perform selected aspects of this project, mission that was accomplished by a team of students during the campaign, and analysis of a crash which concluded the mission.
Technical Paper

Structural and Aerodynamics Analysis on Different Architectures for the Elettra Twin Flyer Prototype

2009-11-10
2009-01-3128
This paper deals with the design and development of an innovative airship concept which is remotely-controlled and intended to be used for monitoring, surveillance, exploration and reconnaissance missions. Two potential solutions have been analyzed: the first consists of a double-hull configuration, characterized by the presence of a primary support structure connected by appropriated bindings to a couple of twin inflatable hulls. The second architecture is a soap-shaped exoskeleton configuration which features a single inflated section, incorporating two separate elements held internally by a system of ribs. The aim of this study is to analyze and compare the two configurations, to determine the most appropriate solution in terms of performance, cost and maneuvering capabilities
Technical Paper

Electronic Power Distribution System Topologies

2009-11-10
2009-01-3122
This paper presents several possible topologies for Electronic Power Distribution Systems. A discussion is presented on the advantages and drawbacks of each topology. Weight savings, reliability increase, diagnostics and prognostics capabilities are discussed. Trade study results are presented to back up the discussion. The paper also presents some options on communication between the power system and the avionics systems.
Journal Article

Role of Power Distribution System Tests in Final Assembly of a Military Derivative Airplane

2009-11-10
2009-01-3121
Boeing has contracts for military application of twin engine airplanes generically identified in this paper as the MX airplane. Unlike previous derivatives, the MX airplanes are produced with a streamlined manufacturing process to improve cost and schedule performance. The final assembly of each MX airplane includes a series of integration tests, called factory functional tests (FFTs), which are modified from those of typical commercial versions and verify correctness of equipment installation and basic functionalities. Two airplanes have been through the production line resulting in a number of FFT lessons learned. Addressed are the power distribution lessons learned: 1) the expanded coverage of the basic automated power-on generation system test, 2) the need for a manual wire continuity test, 3) salient features of the power distribution tests, and 4) keys to make first pass power distribution test smooth and successful.
Technical Paper

Monitoring the Spread of a Plant Pathogen in the Lower Atmosphere using Unmanned Aerial Vehicles and a Buoyancy-Controlled Weather Balloon

2009-11-10
2009-01-3125
Abstract This paper describes an experimental framework to track a meteorological balloon at low altitudes using unmanned aerial vehicles (UAVs). The purpose of the experiment is to simulate the trajectories of plant pathogen spores using a buoyancy controlled weather balloon. In the described framework the balloon is instrumented with an onboard telemetry unit to broadcast its GPS coordinates and other flight and meteorological data. The UAV's circular flight pattern is centered on the current position of the balloon, where the position coordinates are shared over a wireless network. The principal advantage of using the weather balloon is to increase the likelihood of detecting airborne pathogens by sampling inside the spore plume. The apparatus enables the UAVs to sample larger distances away from the source than previously possible.
Technical Paper

Final Assembly Line

2009-11-10
2009-01-3118
Manually aligning and joining completed aircraft sections is historically a time consuming and cumbersome process. Constant manual measuring is required, as well as very fine movements which are difficult to control and accomplish manually. In order to increase both the efficiency as well as the quality and safety of the section join process, BRÖTJE-Automation has developed the Automated Positioning and Alignment System. This paper describes two Positioning and Alignment Systems – one for joining fuselages and one for wing attachment. The Positioning and Alignment Systems are designed with the flexibility to join fuselage sections and wings to the fuselages for a range of different aircraft, all fully automatically through the use of a laser measurement system.
Journal Article

High Temperature Multilayer Ceramic Capacitors

2009-11-10
2009-01-3124
High temperature power electronics have become a vital aspect of future designs of compact power converters for applications including power conditioning and distributed motor/actuator controls. However, the development of high temperature capacitors had lagged far behind other system components (e.g. semiconductor switches and that can operate at temperature >200°C). The performance of these systems would benefit significantly from components and packaging designed and optimized for high temperature (200°C to 400°C) under generally harsh environmental conditions. In this paper it will be demonstrated that high temperature materials can be successfully fabricated into multilayer ceramic capacitors (MLCC). The properties of various capacitors having application range 200∼500°C will be presented.
Technical Paper

A Framework for the Fusion of Multiple Metrology Sources for Measurement Assisted Assembly

2009-11-10
2009-01-3119
Measurement assisted assembly is one of the key emerging technologies in airframe manufacture. The use of metrology to assist with the assembly process can significantly reduce the cost and complexity of the required fixtures as well as reducing manual labor input and assembly time. Most of the existing systems use a single metrology system but this paper describes the development and deployment of a network based system that allows the deployment of multiple metrology systems to support either a single task or multiple tasks simultaneously.
Technical Paper

Power Line Communication Techniques for Multi-User and Higher Data Rate Applications in an Aircraft

2009-11-10
2009-01-3120
Power Line Communication (PLC) is considered one of emerging technologies for the Next Generation Aircraft. Power lines can be used as an internal data exchange media within aircraft subsystems, such as the Electric Power Distribution System (EPDS). PLC is a term which describes the use of existing electrical power lines to provide the medium for a high data speed networks to replace extra cables, thereby reducing the installation cost and net weight in aircraft wiring. This paper reviews different multiple access techniques and advantages/disadvantages of each technique using power line networks as a data communication medium. Power line channels include various types of noise and interference hence there are major challenges when communicating over power lines. A designer must consider the limitations in the power line communication channels such as propagation factor, impedance mismatch, noise and electromagnetic compatibility.
Journal Article

Method and System for Making a Fuel-tank Inert without an Inert Gas

2009-11-10
2009-01-3134
In Chemistry “Inert” implies ‘not readily reactive with other elements; forming few or no chemical compounds or something that is not chemically active’. “Inerting” is the process that renders a substance inert. A method for making a fuel-tank inert without the use of an inert gas is described. In this method fuel-air ratio of ullage is reduced until it becomes inert. The method does not discharge fuel vapors as an inert gas inerting system. Two systems employing the method are described explaining their pros and cons. Advantages of the method over Nitrogen Enriched Air (NEA) inerting method with an On-board Inert Gas Generating System (OBIGGS) are discussed. Patent application on the method and system is pending.
Technical Paper

Laser Tracker and Digital Photogrammetry's Merged Process for Large Scale Rapid Scanning

2009-11-10
2009-01-3088
Aircraft factories today must increase their speed of measurement and manufacturing operations, to remain competitive in the ever expanding global Partner/Supplier environment. Reducing the time required, for data collection and analysis, will increase the implementation of metrology solutions in our collectively networked factories. For aircraft, the challenge is to measure very large areas rapidly, receive near real time feedback, with minimal impact to the production schedule. Several different types of metrology equipment can measure large structures. Combining the strength of two different systems, laser tracker and Digital Photogrammetry, has increased the speed and volume of data collection. The speed and accuracy improvement is achieved by integrating the laser tracker's interferometer for precise distance and scaling calculations, and photogrammetry's rapid large area measurement capabilities.
Technical Paper

New Jig Mounted Wing Panel Riveters, AERAC 2

2009-11-10
2009-01-3089
Electroimpact revisited a piece of automation history this year. In 1989, Electroimpact delivered its first ever Automated Electromagnetic Riveting and Assembly Cell or A.E.R.A.C. to Textron Aero Structures, now Vought Aircraft Industries. These machines produce upper wing panels for Airbus A330/340 aircraft. They were the precursor to the Low Voltage Electromagnetic Riveters or LVER's producing wing panels for Airbus single isle, A340 and A380 programs in Broughton, Wales, UK. In 2009, Electroimpact delivered two next generation AERAC machines to Vought Aircraft Industries. A significant design challenge was to hold the moving mass for the entire machine under 5220 kg without sacrificing performance of the LVER. These machines employ several new technologies to achieve this including Electroimpact's latest generation rivet injector, an integrated headstone load cell, and GE Fanuc's customer board.
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