Criteria

Text:
Display:

Results

Viewing 1 to 30 of 194
2015-09-15
Technical Paper
2015-01-2428
Richard Ambroise, Gabriel Godfrey
The smartphone in your pocket, the tablet you use to browse the web, the safety systems in your automobile: they all benefit from fast-evolving computer and electronic component technology. These components are lighter, hold more data, and can perform increasingly complex tasks. This electronic evolution has had an impact in the aviation industry as well. The electronic components used in today's engines can do more than ever before, but the need to replace older components has introduced some added complexity. Until now. The problem is obsolescence. Driven by an ever-demanding consumer market, electrical components - including those used for aircraft engines - are evolving faster than ever. Engine components installed just a few years ago are no longer being made. This means engine manufacturers need to install new models when replacing these older models or when building new engines.
2015-09-15
Technical Paper
2015-01-2551
Ephraim Suhir, Alain Bensoussan, Johann Nicolics
In some today's and future electronic and optoelectronic packaging systems (assemblies), including those intended for aerospace applications, the package (system's component containing active and passive devices and interconnects) is placed (sandwiched) between two substrates. In an approximate stress analysis these substrates could be considered, from the mechanical (physical) standpoint, identical. Such assemblies are certainly bow-free, provided that all the stresses are within the elastic range and remain elastic during testing and operation. Ability to remain bow-free is an important merit for many applications. This is particularly true in optical engineering, where there is always a need to maintain high coupling efficiency. The level of thermal stresses in bow-free assemblies of the type in question could be, however, rather high.
2015-09-15
Technical Paper
2015-01-2549
Marc-André Léonard, Jean-François Boland, Christophe Jégo, Claude Thibeault
Abstract Design assurance guidance such as DO-254, and commercial off the shelf (COTS) increasing popularity in high critical mission have pushed the validation and verification methodologies to improve by integrating fault tolerance analysis in reliability assessment. A novel methodology for analysing the sensitivity of digital designs to single event upsets (SEU) is proposed. We first characterize basic combinational circuit models using fault injection via mutation technique at low level of abstraction. Error analysis is performed at primary outputs to identify patterns that are collected in a faulty behaviour library. This library is then used at a high level of abstraction to execute a sensitivity analysis on a digital design model. A reliability report is then generated showing the soft error rate (SER) and the benign errors count. We proved our methodology by analysing the radiation sensitivity of a discrete wavelet transform architecture using two different sets of data.
2015-09-15
Technical Paper
2015-01-2536
Rinky Babul Prasad, Vinukonda Siddartha
Abstract Recent years have seen a rise in the number of air crashes and on board fatalities. Statistics reveal that human error constitutes upto 56% of these incidents. This can be attributed to the ever growing air traffic and technological advancements in the field of aviation, leading to an increase in the electronic and mechanical controls in the cockpit. Accidents occur when pilots misinterpret gauges, weather conditions, fail to spot mechanical faults or carry out inappropriate actions. Currently, pilots rely on flight manuals (hard copies or an electronic tablet) to respond to an emergency. This is prone to human error or misinterpretation. Also, a considerable amount of time is spent in seeking, reading, interpreting and implementing the corrective action. The proposed augmented head mount virtual assist for the pilot eliminates flight manuals, by virtually guiding the pilot in responding to in-flight necessities.
2015-09-15
Technical Paper
2015-01-2530
Pierre Dissaux
Abstract The Architecture Analysis and Design Language (AADL) SAE standard [1] defines a default runtime semantic for software intensive real time systems. This includes support for multi tasking, network distributed architectures and Time and Space Partitioning systems (TSP). The core definition of the language is extended by the Behavior Annex that enables a more precise specification of the application real-time behavior. This allows for the definition of functional pseudo-code for AADL threads and subprograms. It becomes thus possible to describe for instance critical sections or conditional computation depending on input port values while remaining in the scope of the AADL standard. Such a consistent behavioral model can be used for various performance analyses like scheduling and simulation in the early phases of the software development process of real-time critical systems.
2015-09-15
Journal Article
2015-01-2532
Sylvain Hourlier, Sandra Guérard, Jean Luc BAROU, Xavier Servantie
Abstract As touch screens are everywhere in the consumer market Thales has launched in depth evaluations on their introduction in the cockpit. One of the challenges is to verify its compatibility with in flight use under turbulence conditions, including light, moderate and severe. In flight accelerometer collections were performed to provide us with a baseline for choosing between possible simulation solutions. Thales recognized early on the need for such a tool as it would enable us to define recommendations for our HMI designs. The objectives were first to validate specific complex touch/gestures using all the potential of touch interactions for novel cockpit Human Machine Interfaces and second to look into the various physical anchoring solutions capable of facilitating touch screens interactions in aeronautical turbulent environments.
2015-09-15
Technical Paper
2015-01-2571
Cornelis Bil, Man Chiu Fung, Sherman C.P. Cheung, Piergiovanni Marzocca
Abstract This paper introduces the Seabus SB-8, a new Wing-In-Ground-Effect (WIGE) craft designed for 8 - 10 passengers. The craft will be used for fast transportation across Port Phillip Bay in Melbourne, Australia. With a cruise speed of about 140 km/hr, it can cross the bay in 30 min as compared to 75 min for land transportation. Computational Fluid Dynamics (CFD) analysis was conducted on the design to determine aerodynamic properties at various angles of attack and operating heights. The influence of ground effect was also determined as well as the effect of Centre of Gravity (CG) position on longitudinal stability. Using flow visualization areas of potential flow separation were identified and interactions of wake vortices with different parts of the aircraft were determined. Note that some aspects of the design are proprietary.
2015-09-15
Technical Paper
2015-01-2569
Georges Ghazi, Ruxandra Botez
Abstract During aircraft development, mathematical models are elaborated from our knowledge of fundamental physical laws. Those models are used to gain knowledge in order to make the best decisions at all development stages. Depending on the application, different models can be used to describe, in one way or another, the aircraft behavior. The goal of this paper is to develop a high-fidelity aircraft simulation model that is exceptionally capable, flexible and responsive to the needs of the researchers. The proposed model includes nonlinear aerodynamic coefficients, a generic engine model and a complete autopilot with auto-landing. The simulation model has been designed to help researchers develop and validate new algorithms for trajectory optimization, control design, stability analysis and parameter estimation. To make it easy to use, the simulation model also includes algorithms for stability and control analysis.
2015-09-15
Technical Paper
2015-01-2567
Dushyant Kaliyari, Khadeeja Nusrath TK, Jatinder Singh
Abstract Aerodynamic database update from the flight tests using system identification techniques is a crucial tool for the development of control laws and high fidelity simulators. For the certification of aircraft under test, aero-database needs to be validated from flight tests throughout the flight envelope and also to certain levels beyond the envelope boundaries. Validation of aero-database close to envelope boundaries entails additional complexities which necessitates careful handling of flight data identification and update process. This paper discusses the approach adopted for aero-database update and flight clearance, followed by a discussion on the issues relevant in the extreme flight test regimes, such as, flow angle accuracy at higher angles-of-attack, center-of-gravity variation with fuel pitch angle for high-g maneuvering conditions and inaccuracies in Mach number at transonic speeds.
2015-09-15
Technical Paper
2015-01-2565
Nhan Nguyen, Sonia Lebofsky, Eric Ting, Upender Kaul, Daniel Chaparro, James Urnes
Abstract This paper summarizes the recent development of an adaptive aeroelastic wing shaping control technology called variable camber continuous trailing edge flap (VCCTEF). As wing flexibility increases, aeroelastic interactions with aerodynamic forces and moments become an increasingly important consideration in aircraft design and aerodynamic performance. Furthermore, aeroelastic interactions with flight dynamics can result in issues with vehicle stability and control. The initial VCCTEF concept was developed in 2010 by NASA under a NASA Innovation Fund study entitled “Elastically Shaped Future Air Vehicle Concept,” which showed that highly flexible wing aerodynamic surfaces can be elastically shaped in-flight by active control of wing twist and bending deflection in order to optimize the spanwise lift distribution for drag reduction.
2015-09-15
Technical Paper
2015-01-2561
Fernando Stancato, Sandro Conceicao, Ramon Papa, Luis Santos
Abstract Nowadays CFD analysis including virtual manikins is vastly applied to evaluate thermal comfort inside different working environments, such as buildings cars and aircrafts. Inside aircraft cabins, added to the numerical challenges due to geometrical complexity, the available subjective responses used to judge occupant local thermal comfort are usually based on buildings and cars experiments [1]. In the present paper however, it is applied an aircraft based subjective responses to evaluate thermal comfort which was specifically developed using regional jet mock-up experiments. The evaluation for the two approaches will be compared providing insight of the main differences.
2015-09-15
Technical Paper
2015-01-2563
Alberto Charro, Solange Baena, Joseph K-W Lam
Abstract The paper presents an extensive assessment of the hygroscopic characteristics of a number of alternative jet fuel blends. These are blended with conventional Jet A-1 to conform with current aviation standards at a 50:50 ratio by volume, except for DSHC (Direct Sugar to Hydrocarbon), which is blended at 10% DSHC and 90% Jet A-1. Given the lack of information available on the water solubility of alternative jet fuels, an effective analysis of experimental data about this characteristic in six different alternatives was performed. These included four ASTM approved alternatives (two Fischer-Tropsch (FT) synthetics from coal and natural gas, one HEFA (Hydroprocessed Esters and Fatty Acids) derived from camelina and DSHC. An extra two alternatives currently under consideration for ASTM approval were also tested; ReadiJet and an ATJ (Alcohol to Jet).
2015-09-15
Technical Paper
2015-01-2553
Markus Dahlweid, Jörg Brauer, Jan Peleska
Abstract Model-based development is a well-established and widely used technique to design and implement systems by specifying the overall architecture of a system and its behavior directly in modeling tools such as PTC Integrity Modeler, Enterprise Architect, Modelio, or Papyrus/Eclipse. The next step forward in this process is using the same framework also for the design and specification of the tests for these systems. Verified Systems International GmbH offers with RT-Tester MBT a novel approach to model-based embedded systems testing, which we are going to present in this paper. Model-based testing (MBT) offers automated generation of test cases, test data and test procedures for model-in-the-loop, hardware-in-the-loop and system testing from UML/SysML models describing the intended system behavior [17,20].
2015-09-15
Technical Paper
2015-01-2555
Ephraim Suhir, Alain Bensoussan, Johann Nicolics
There is a concern that the continuing trend on miniaturization (Moore's law) in IC design and fabrication might have a negative impact on the device reliability. To understand and to possibly quantify the physics underlying this concern and phenomenon, it is natural to proceed from the experimental bathtub curve (BTC) - reliability “passport” of the device. This curve reflects the combined effect of two major irreversible governing processes: statistics-related mass-production process that results in a decreasing failure rate with time, and reliability-physics-related degradation (aging) process that leads to an increasing failure rate. It is the latter process that is of major concern of a device designer and manufacturer. The statistical process can be evaluated theoretically, using a rather simple predictive model.
2015-09-15
Technical Paper
2015-01-2593
Jonathan L. Geisheimer, Michael Wabs, Carlos Carvalho
Abstract Time Domain Reflectometery (TDR) is a Radio Frequency (RF) technology that has been used for many years to find cable breaks and measure fluid levels in industrial processes. The technology uses picosecond length pulses and the associated reflections off the fluid surface in a time of flight measurement to determine fluid height. TDR signals have additional information that can be processed and utilized for Integrated Vehicle Health Management (IVHM) applications. For example, when water collects in the fuel tank, TDR is capable of identifying and measuring the amount of water. This can allow the water sumps to be drained on condition instead of on a schedule. In addition, electromagnetic properties of the fluid can be determined, such as the dielectric constant, which can be used to identify mis-fueling situations, contaminants in the fluid, and potentially other fluid health properties.
2015-09-15
Technical Paper
2015-01-2589
Julien Feau, Philippe Chantal, Jayant Sen Gupta
Abstract Modern aircraft, such as A380 or A350 for Airbus, are very well connected in flight to ground stations through wireless communications. For maintenance and operations purpose, the aircraft is programmed to send regularly information such as flight reports based on the BITE messages (Built-In Test Equipment) or standard reports based on the value of physical parameters. Moreover, Airbus is capable of sending requests (called uplinks) to the aircraft to retrieve the value of different parameters in almost real-time. This ability, associated with adequate process, improves significantly the reaction time of the diagnostic and prognostic solutions that Airbus can provide to its customers. Traditionally Health Monitoring is considered useful when the Potential to Functional failure (P-F) interval is greater than one flight cycle.
2015-09-15
Technical Paper
2015-01-2587
Matthew Smith, Peter F. Sulcs, Rhonda Walthall, Mark Mosher, Gregory Kacprzynski
Abstract The Aircraft System Health Management (ASHM) tool is a UTC developed web application that provides access to Aircraft Condition Monitoring Function (ACMF) reports and Flight Deck Effects (FDE) records for Boeing 787®, A320®, and A380® aircraft. The tool was built with a flexible architecture to field a range of off-board diagnostics and prognostics modules designed to transform an abundance of data into actionable and timely knowledge about fleet health. This paper describes the system architecture and implementation with a focus on “lessons learned” in applying diagnostic and prognostics algorithms to available fleet data. Key topics include ensuring analytic robustness, design for cross-enterprise collaboration and defining a workable approach to testing, validating and deploying prognostics and diagnostics models with various degrees of complexity. A case study is provided related to fluid leak detection within an environmental control subsystem.
2015-09-15
Technical Paper
2015-01-2585
Tuur Benoit, Yves Lemmens, Wim Desmet PhD
Abstract This paper proposes a solution for utilizing multi-body models in nonlinear state observers, to directly estimate the loads acting on the aircraft structure from measurement data of sensors that are commonly available on modern aircraft, such as accelerometers on the wing, rate gyros and strain gages. A high-fidelity aeroelastic multi-body model of a fixed-wing large passenger aircraft is presented, suitable for the monitoring of landing maneuvers. The model contains a modally reduced flexible airframe and aerodynamic forces modeled with a doublet-lattice method. In addition, detailed multi-body models of the nose and main landing gear are attached to the flexible structure, allowing to accurately capture the loads during a hard landing event. It is expected that this approach will make way for embedding non-linear multi-body models, with a high number of degrees of freedom, in state estimation algorithms, and hence improve health monitoring applications.
2015-09-15
Technical Paper
2015-01-2575
Swen Noelting, Ehab Fares
Abstract An overview of the theory and applications of the Lattice-Boltzmann Method (LBM) is presented in this paper. LBM has gained a reputation over the past decade as a viable alternative to traditional Reynolds-averaged Navier-Stokes (RANS) based methods for the solution of computational fluid dynamics (CFD) applications in the aerospace and automotive industries. The theoretical background of the method is presented and the key differentiators to traditional RANS methods are summarized. We then look at current and potential future applications of CFD in the aerospace industry and identify a number of areas where the limitations of RANS tools, in particular with regard to unsteady flows and the handling of complex geometries, prevent a deeper penetration of CFD into product development processes in the aerospace industry.
2015-09-15
Technical Paper
2015-01-2573
Kyle J. Forster, Tracie Barber, Sammy Diasinos, Graham Doig
Abstract Streamwise vortices can be observed to interact in a number of real world scenarios. Vortex generators operating in boundary layers, as well as aircraft flying in formation can produce vortex interactions with multiple streamwise vortices in close proximity to each other. The tracking of these vortex paths as well as the location and nature of their breakdown is critical to determining how the structures can be used to aid flow control, and how large scale turbulence develops from them. Six configurations of two NACA0012 vanes were evaluated computationally to observe the interactions of a pre-existing vortex with a vortex generated downstream. Co and counter-rotating configurations at three different lateral spacings were used to vary vortex position and impingement on the rear vane.
2015-09-15
Technical Paper
2015-01-2626
Charla Wise
Abstract The nature of aerospace innovation has changed dramatically in the past few decades, including some subtle changes that might go unnoticed to a casual observer outside our industry. The achievements of the 1950s through the 1990s were often epitomized by events that made headlines throughout the world - for example, breaking the sound barrier, walking on the Moon, receiving the first images from a roving vehicle on Mars, or launching the first airliner designed solely using computers. Aerospace engineers today are creating feats that are no less innovative or impressive but that often lack the universal sensational appeal of those past “miracles.” Now the accomplishments are likely to be concerned with using data more effectively to reduce risk and enhance the safety and affordability of products and services rather than flying faster, higher or more stealthily.
2015-09-15
Technical Paper
2015-01-2618
Bernd-Michael Wolf, Christian Meiners
Abstract SCALE is a modular, non-contact, in-line measurement system. It measures the diameter of the countersink directly after the drilling, the amount and distribution of sealant in the open hole, and the head height of the fastener as well as pressed out sealant (cf. Figure 1). The system is fast and reliable and the out coming information is reliable and trustworthy. Until now the system could not measure the inner diameter of the hole. The reason for this is that it is not possible to detect the inner diameter with a camera that looks only at the top of the component. But as our customers make the request to us, we decided to develop an optical hole probe system which is fully integrated in the auto fastening process. We think that a mechanical system cannot fulfill the customer expectations in terms of reliability, low maintenance, precision and speed. Only a non-contact system can measure permanently safe and fast the inner diameter of holes.
2015-09-15
Journal Article
2015-01-2611
Samuel Baha II
Abstract The use of composite materials in aircraft manufactures increases more and more with the need of light weight and efficient airplanes. Combining composite materials with an appropriate joining method is one of the primordial ways of exploiting its light weight potential. Since the widely-established mechanical fastening, which originally, was developed for metallic materials, is not a suitable joining method for composite materials because of its low bearing strength, the adhesively bonding technology might be an appropriate alternative. However, adhesively bonding in the aircraft manufacturing, especially for joining of primary structures is liable to certification requirements, such as testing of every bond up to limit load before the operation begins or non-destructive testing of every bond before the operation begins as proof of the joint characteristics, which cannot be fulfilled with the current state of the art.
2015-09-15
Technical Paper
2015-01-2605
Jamnie Yazmín Achem Calahorra, Hilda E. Esparza Ponce, Patricia Zambrano Robledo, Facundo Almeraya Calderón, Citlalli Gaona Tiburcio
Abstract Thin films deposited by magnetron sputtering are review in terms of their potential and present uses in the aircraft industry. The aircraft alloys substrates were Ti-6Al-4V and Incoloy 800HT, using a target of yttrium stabilized zirconia (YSZ) with nominal composition of 8% Y2O3 (wt%) and the remainder of ZrO2. The chemical composition of the films was determined by X-ray energy dispersion (EDS). The electrochemical noise behavior show that the coatings decreased propagation of pitting, leading to a state of passivation or uniform corrosion, and also possess superior corrosion resistance over the individually substrates.
2015-09-15
Technical Paper
2015-01-2601
Zhejun Yao, Wiltrud Weidner, Robert Weidner, Jens Wulfsberg
Abstract Despite the increasing application of automated systems, manual tasks still plays an important role in industrial production. The intelligence and flexibility of human enable quick response and adaptive production for the individual requirements and the changes in market. Moreover, some manufacturing tasks with sensible and high-value components (e.g., in electronic and aircraft production) requires attentive manual handling. Regarding the requirement of increasing productivity as well as ergonomic improvement and the aging of the employees, there is a significant need for technologies which support the staff individually by performing tasks. Human Hybrid Robot, a hybrid system with direct coupling (serial and/or parallel) of human and mechatronic elements, is a new trend in application of robotic technologies for supporting manual tasks. It realizes a synchronous and bidirectional interaction between human and mechatronic and/or mechanic elements in the same workspace.
2015-09-15
Journal Article
2015-01-2595
Darren Winter, Paul Ashton-Rickardt, Carwyn Ward, Paul Gibbons, Chris Mcmahon, Kevin Potter
Abstract This paper reports on a methodology for risk reduction, developed and tested at a brand new aerospace manufacturing facility, producing high value aero-structures. The facility was formed as part of a ‘Risk Sharing Partnership’ between Airbus and GKN for production of the Airbus A350 ‘Fixed Trailing Edge’ (FTE). Whilst operating in New Product Introduction (NPI), the challenge for GKN was to increase production volume for each successive year of operations. At the time of writing, the facility was producing FTE structures at a rate of 4 per month i.e. Rate 4, and attempting to transition to Rate 6. The ultimate aim was to produce FTE structures at Rate 13 within an 8 year period whilst concurrently engineering the product and improving its processes. For schedule adherence, elimination of process failures was critical and often manifested at the final stage of assembly (integration cell).
2015-09-15
Technical Paper
2015-01-2455
Roshen Jay Jaswantlal, Piergiovanni Marzocca, Rafael Palacios
Abstract The implementation of Synthetic Jet Actuators (SJAs) on Unmanned Aerial Vehicles (UAVs) provides a safe test-bed for analysis of improved performance, in the hope of certification of this technology on commercial aircraft in the future. The use of high resolution numerical methods (i.e. CFD) to capture the details of the effects of SJAs on flows and on the hosting lifting surface are computationally expensive and time-consuming, which renders them ineffective for use in real-time flow control implementations. Suitable alternatives include the use of Reduced Order Models (ROMs) to capture the lower resolution overall effects of the jets on the flow and the hosting structure. This research paper analyses the effects of SJAs on aircraft wings using a ROM for the purpose of determining the unsteady aerodynamic forces modified by the presence of the SJAs. The model developed is a 3D unsteady panel code where the jets are represented by source panels.
2015-09-15
Technical Paper
2015-01-2453
Danilo Andreoli, Mario Cassaro, Manuela Battipede, Goodarz Ahmadi, Piergiovanni Marzocca
Abstract Flow control over aerodynamic shapes in order to achieve performance enhancements has been a lively research area for last two decades. Synthetic Jet Actuators (SJAs) are devices able to interact actively with the flow around their hosting structure by providing ejection and suction of fluid from the enclosed cavity containing a piezo-electric oscillating membrane through dedicated orifices. The research presented in this paper concerns the implementation of zero-net-mass-flux SJAs airflow control system on a NACA0015, low aspect ratio wing section prototype. Two arrays with each 10 custom-made SJAs, installed at 10% and 65% of the chord length, make up the actuation system. The sensing system consists of eleven acoustic pressure transducers distributed in the wing upper surface and on the flap, an accelerometer placed in proximity of the wing c.g. and a six-axis force balance for integral load measurement.
2015-09-15
Technical Paper
2015-01-2459
Francesco Cappello, Subramanian Ramasamy, Roberto Sabatini
Abstract Multi-Sensor Data Fusion (MSDF) techniques involving satellite and inertial-based sensors are widely adopted to improve the navigation solution of a number of mission- and safety-critical tasks. Such integrated Navigation and Guidance Systems (NGS) currently do not meet the required level of performance in all flight phases of small Remotely Piloted Aircraft Systems (RPAS). In this paper an innovative Square Root-Unscented Kalman Filter (SR-UKF) based NGS is presented and compared with a conventional UKF governed design. The presented system architectures adopt state-of-the-art information fusion approach based on a number of low-cost sensors including; Global Navigation Satellite Systems (GNSS), Micro-Electro-Mechanical System (MEMS) based Inertial Measurement Unit (IMU) and Vision Based Navigation (VBN) sensors.
2015-09-15
Technical Paper
2015-01-2457
Jae Chung, Yushing Cheung
Abstract In this paper, we investigate the formation control of multiple unmanned aerial vehicles (UAVs) in an obstacle-laden environment for target tracking. The main contribution of this paper is to develop a potential field based leader-follower formation control method for target tracking and obstacle/collision avoidance. In the potential field, a quantity of virtual positive charge carried by each of UAVs varies depending upon their roles as a leader or follower when obstacles and targets are regarded as ions with larger positive and negative charges, respectively. Therefore, the formation formed by the UAVs connected with their inter-bonds could be adapted while the UAVs get around the obstacles and are attracted to the targets. The potential field based leader-follower formation control method is developed to reshape a UAV team configuration to track a target while the UAV team avoids the obstacles.
Viewing 1 to 30 of 194

Filter

  • Range:
    to:
  • Year: