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2017-10-08
Technical Paper
2017-01-2408
Lei Zhou, Hongxing Zhang, Zhenfeng Zhao, Fujun Zhang
The Opposed Piston Two-Stroke (OPTS) engine has several advantages for power density, fuel tolerance, fuel efficiency and package space. A new type of balanced opposed-piston folded-crank train two-stroke engine for Unmanned Aerial Vehicle (UAV) was studied in this paper. The effects of high altitude environment on engine performance and emissions are investigated by thermodynamic simulation. Moreover, the matching between the engine and turbocharger was designed and optimized for different altitude levels. The results indicate that a suitable turbocharger for OPTS engine can achieve the purpose of improving the quality of scavenging, lowering the fuel consumption and recovering power at high altitude environment. Finally, an optimized OPTS engine model especially for UAV is proposed in this research.
2017-09-19
Technical Paper
2017-01-2053
Jim Stabile
Since oxygen has been a part of the aircraft system it has always been managed using a difficult metric to understand.......PSI. Today's technology has allowed us to efficiently and inexpensively convert PSI into a timed based metric which allows for improved oxygen management and a method which provides an interface between two important energy aircraft resources (fuel and oxygen). These resources have inverse consumption rates tied directly to the altitude of the aircraft. Using time as the management metric, the pilot can balance these 2 resources during any oxygen contingency by varying the altitude of the aircraft.. This allows for regulatory fuel savings and an increase in operational safety This program diverges from traditional thinking in that it applies an information and skill based solution to a system that has otherwise been viewed as a hardware problem.
2017-09-19
Technical Paper
2017-01-2159
Federico Cappuzzo, Olivier Broca, Jeremy Leboi
To answer the ever-increasing complexity of aircraft, it becomes of foremost importance to better and earlier assess the interactions among their systems and sub-systems. The study presents the Virtual Integrated Aircraft (VIA) methodology, which allows achieving the integration of aircraft systems with virtual means, complementing and preceding physical integration, which is usually completed at the end of the validation and integration phase. LMS Imagine.Lab platform provides the means for applying this methodology. A simulation architecture, integrating models from different platforms, is built and simulations are run on High Performance Computers (HPC) to cover multiple scenarios and therefore validate the selected architecture and pre-design in the early system development phases. Equipment, systems and subsystems are essential for the performance, safety, reliability and comfort.
2017-09-19
Technical Paper
2017-01-2073
Rick Calawa
The decision to completely replace a successful automated production system at the heart of a high volume aircraft factory does not come easily. A point is reached when upgrades and retrofits are insufficient to meet increasing capacity demands and additional floor space is simply unavailable. The goals of this project were to greatly increase production volume, reduce floor space, improve the build process, and smooth factory flow without disrupting today’s manufacturing. Two decades of lessons learned were leveraged along with advancements in the aircraft assembly industry, modern machine control technologies, and maturing safety standards to justify the risk and expense of a ground-up redesign. This paper will describe how an automated wing spar fastening system that has performed well for 20 years is analyzed and ultimately replaced without disturbing the high manufacturing rate of a single aisle commercial aircraft program.
2017-09-19
Technical Paper
2017-01-2110
Ashutosh Kumar Jha, Prakash Choudhary
The complexity of software development is increasing unprecedentedly with every next generation of aircraft systems. This requires to adopt new techniques of software design and verification that could optimize the time and cost of software development. At the same time these techniques need to ensure high quality of software design and safety compliance to regulatory guidelines like DO-178C[1] and its supplements DO-330[2] and DO-331[3]. To arrive at new technologies one has to evaluate the alternate methods available for software design by developing models, integration of models, auto-code generation, auto test generation and also the performance parameters like time, effort, reuse and presentability needs to be evaluated. We have made an attempt to present summary of alternate design concept study, and edge of MBD over other design techniques.
2017-09-19
Technical Paper
2017-01-2135
Alex Thirkell, Rui Chen, Ian Harrington
Electrification of aircraft is on track to be a future key design principal due to the increasing pressure on the aviation industry to significantly reduce harmful emissions by 2050 and the increased use of electrical equipment. This has led to an increased focus on the research and development of alternative power sources for aircraft, including fuel cells. These alternative power sources could either be used to provide propulsive power or as an Auxiliary Power Unit (APU). Previous studies have considered isolated design cases where a fuel cell system was tailored for their specific application. To accommodate for the large variation between aircraft, this study covers the design of an empirical model, which will be used to size a fuel cell system for any given aircraft based on basic design parameters. The model was constructed utilising aircraft categorisation, fuel cell sizing and balance of plant sub-models.
2017-09-19
Technical Paper
2017-01-2126
Ashutosh Kumar Jha, Gaurav Sahay, Adishesha Sivaramasastry
In aerospace industry, the concept of Integrated Vehicle Health Management (IVHM) has gained momentum and is becoming need of the hour for entire value chain in the industry. Identifying and sensing right parameters at right time is the key for success of IVHM. It has opened up challenge to the sensor providers to make sensors smarter, self-contained to compute and communicate efficiently. The expected benefits of lesser time to maintenance, reduced operating cost and very busy airports are motivating aircraft manufacturers to come up with tools, techniques and technologies to enable advanced diagnostic and prognostic systems in aircrafts. These features not only enable detection of failures but also support prediction of tentative failures upfront based on historical data, trend analysis and estimating the future trends. At present, various groups are working on different systems and platforms for health monitoring of an aircraft e.g.
2017-09-19
Technical Paper
2017-01-2042
Matthew Diggs
ABSTRACT A newly-invented "X"-configuration engine utilizing the Scotch yoke mechanism renders potential for the best power/weight ratio of any diesel engine. Given the efficiency advantage of 4-stroke turbo-diesel cycle over turbine engines, a study reveals that X-engines may be a preferable solution to turbines for airplanes, helicopters and UAVs up to 60000 lbs max. takeoff weight. Calculations indicate potential for 35 to 60% lower fuel consumption with no compromise to payload, range, cruise speed, maximum speed, takeoff power or maximum takeoff weight. Outline: I. CAE study of the double-acting Scotch yoke mechanism indicates feasibility for 4-stroke turbo-diesel cycle. a) kinematic analysis b) essential new components: piston, yoke, bearing block c) FEA optimized DASY system for 4-stroke diesel cycle d) apples-to-apples comparison of DASY to connecting rod: bearing pressures, part count, torque delivery, engine balance, package. II.
2017-09-19
Technical Paper
2017-01-2043
Pejman Akbari, Lucas Bermudes
Reducing the scale of the power engines, pose problems that are not encountered at large scale. Several effects, which are negligible at large scale, prove to dominate these viscous forces driven flows. Particularly, it is useful to investigate unsteady machines at small scales when subject to pressure waves. In this paper, the effects of scale on the propagation of shock waves in narrow shock tubes are studied using analytical and numerical modeling approaches. It is discussed how the size scale can become a decisive factor in governing the behavior of these small-scale devices. The results, in agreement with previous studies, suggest that the wall viscous stresses and heat conduction lead to deviation in flow characteristics compared to ideal shock wave behaviors observed in larger scales. The numerical results show shock-wave attenuation along the length of a narrow shock tube, in accordance with the developed analytical models.
2017-09-19
Technical Paper
2017-01-2046
Pejman Akbari, Ian Agoos
The Wave Disk Engine (WDE) is a novel engine that has the potential for higher efficiency and power density of power-generation systems. A recent version of wave disk engine architecture known as the two-stage WDE has been studied to address existing challenges of an existing WDE. After describing the engine operation, a cold air-standard thermodynamic model supporting the physical phenomena occurring inside the device is introduced to evaluate performance of the engine. The developed model is general and does not depend on the shape of the wave rotor, it can be applied to radial and axial combustion wave rotors integrated with turbomachinery devices. The analysis starts with predicting internal waves propagating inside the channels of the engine and linking various flow states to each other using thermodynamics relationships. The goal is to find analytical expressions of work output and efficiency in terms of known pressure and temperature ratios.
2017-09-19
Technical Paper
2017-01-2050
Piotr Synaszko, Michal Salacinski, Patryk Ciezak
The work concerns the selection of measurement parameters for selected non destructive testing methods of Mi helicopter rotor blades after repair. Considered repair cases involve metal cracks in the sandwich skin and repair damage of honeycomb structure structure (puncture, dent). In the event of a crack, repair is performed by applying a composite-metal repair package. In case of damage of the core, its broken piece is replaced by a new one and then applied the same metal-composite package as in the case of crack repair. The present work focuses on detecting disbond between skin and core below repair patch and cracks under the repair package. Detecting cracks and assessing their length is important because the repair technology provides the repair package without removing of cracked part of skin. Authors have used laser shearography and C-scan methods for MIA and ET.
2017-09-19
Technical Paper
2017-01-2125
Mohammad Barkat, Vivek Karan, Pradeep N
The exponential increase in the number of aircrafts and air travellers has triggered new innovations which aim to make airline services more reliable and consumer friendly. Quick and efficient maintenance actions with minimum downtime are the need of the hour. Areas that have a large potential for improvement in this regard are the real time use of diagnostic data, filtering/elimination of nuisance faults and machine learning capabilities with respect to maintenance actions. Although, numerous LRUs installed on the aircraft generate massive amounts of diagnostic data to detect any possible issue or LRU failure, it is seldom used in real time. The turnaround time for LRU maintenance can be greatly reduced if the results of the diagnostics conducted during LRU normal operation is relayed to ground stations in real-time. This enables the maintenance engineers to plan ahead and initiate maintenance actions well before the aircraft lands and becomes available for maintenance.
2017-09-19
Technical Paper
2017-01-2020
Michael Croegaert
Modern military aircraft platforms are using more and more power which results in an ever increasing power density (SWaP). This in turn, generates more heat that has to be dissipated from the instrument panel and cockpit of the aircraft. Complicating this further is that the use of structural composites which are not efficient conductors of heat and the mission requirements of small heat signatures. Therefore alternative means of extracting the heat from the avionics systems must be used. Liquid cooled systems have the advantage over air cooled systems of a much higher heat transfer rate and the fact that the heat can be transported a significant distance from the source. Liquid cooled avionics have their own challenges as well. The architecture of the components (cold plates, etc) used for extracting the heat from the electronics component must be optimized to perform consistently and reliably while maintaining the smallest footprint possible in the already crowded instrument panel.
2017-09-19
Technical Paper
2017-01-2034
Bailey Hall, Benjamin Palmer, Tyler Milburn, Luis Herrera, Bang Tsao, Joseph Weimer
Abstract Future aircraft will demand a significant amount of electrical power to drive primary flight control surfaces. The electrical system architecture needed to source these flight critical loads will have to be resilient, autonomous, and fast. Designing and ensuring that a power system architecture can meet the load requirements and provide power to the flight critical buses at all times is fundamental. In this paper, formal methods and linear temporal logic are used to develop a contactor control strategy to meet the given specifications. The resulting strategy is able to manage multiple contactors during different types of generator failures. In order to verify the feasibility of the control strategy, a real-time simulation platform is developed to simulate the electrical power system. The platform has the capability to test an external controller through Hardware in the Loop (HIL).
2017-09-19
Technical Paper
2017-01-2039
Michael Sielemann, Changsoo Lee, Victor-Marie LeBrun, Chiwoo Ahn, Arnaud Colleoni, Dongkyu Lee, JeongSeok Lee, Anh Nguyen, Katrin Proelss, Hyon Min Yoon
Abstract Thermal management on aircraft has been an important discipline for several decades. However, with the recent generations of high performance aircraft, thermal management has evolved more and more into a critical performance and capability constraint on the whole aircraft level. Fuel continues to be the most important heat sink on high performance aircraft, and consequently the requirements on thermal models of fuel systems are expanding. As the scope of modeling and simulation is widened in general, it is not meaningful to introduce a new isolated modeling and simulation capability. Instead, thermal models must be derived from existing model assets and eventually enable integration across several physical domains. This paper describes such an integrated approach based on the Modelica Fuel System Library and the 3DExperience Platform.
2017-09-19
Technical Paper
2017-01-2109
Kiran Thupakula
Abstract Airport environments consist of several moving objects both in the air and on the ground. In air moving objects include aircraft, UAVs and birds etc. On ground moving objects include aircraft, ground vehicles and ground personnel etc. Detecting, classifying, identifying and tracking these objects are necessary for avoiding collisions in all environmental situations. Multiple sensors need to be employed for capturing the object shape and position from multiple directions. Data from these sensors are combined and processed for object identification. In current scenario, there is no comprehensive traffic monitoring system that uses multisensor data for monitoring in all the airport areas. In this paper, for explanation purposes, a hypothetical airport traffic monitoring system is presumed that uses multiple sensors for avoiding collisions.
2017-09-19
Technical Paper
2017-01-2155
Michal Salacinski, Piotr Broda, Piotr Samoraj
Abstract Polish Armed Forces are currently operating hundred helicopters belonging to Mi family. Metal fuselage is usually resistant to the battle and the human factor. Unfortunately, metal rotor blades of Mi helicopters are sensitive to operating conditions. Single blade is made from monolithic aluminum spar and mutually separated trailing sections, which are bonded to the spar. The sections are constructed of metal sandwich panels. During aggressive military operating conditions blades sections are often damaged by debonding from the spar, fatigue cracks of section skin, dents and perforations as well as erosion. The manufacturer assumed that structurally damaged sections should be exchanged. Provided repair technologies are applied only to cosmetic damages. Unfortunately, there is a limit to number repairs which prevents replacement of two neighboring sections due to the high temperature of curing cycle during the section replacement.
2017-09-19
Technical Paper
2017-01-2158
Fernando Stancato, Luis Carlos dos Santos, Marcelo Pustelnik
Abstract A problem of interest of the aeronautical industry is the positioning of electronic equipment in racks and the associated ventilation system project to guarantee the equipment operational conditions. The relevance of the proper operation of electronic equipment increases considerably when high economical costs, performance reduction and safety are involved. The appropriate operational conditions of the electronic components happen when the working temperature of the equipment installed in the rack is inside a safety project temperature margin. Therefore, the analysis and modelling of heat transfer processes for aircraft rack design becomes mandatory. This paper presents a parametric study considering volumetric and superficial heat generation in electronic equipment within racks in an aircraft. Simulations were performed using the commercial CFD Fluent code and results were compared to experimental data.
2017-09-19
Technical Paper
2017-01-2077
John McClelland, Michael Morgan, Caroline McClory, Colm Higgins, Rory Collins, Adrian Murphy, Yan Jin
The need to drill several million holes per aircraft through composite and hybrid material stacks is a large challenge for the aerospace assembly process. The ability to produce high quality holes for the lowest tooling costs is at the forefront of requirements for aircraft assembly factories worldwide. Consequently, much research has been conducted into tool design and development, however, the effect of drilling platform characteristics has not been well covered in literature. Respectively, this research has compared the drilling abilities of a 5-axis precision CNC platform, a hybrid parallel kinematic machine and an articulated robotic arm fitted with a drilling module. In-process force measurement and post process hole and tool analysis methods were used to better understand the effect of static and dynamic platform characteristics on the achievable hole quality, cycle time and tool wear when drilling aerospace metal alloy stacks.
2017-09-19
Technical Paper
2017-01-2107
Thorsten Kiehl, Jan Philip Speichert, Ethan Higgins, Ralf God
For an “end-to-end passenger experience that is secure, seamless and efficient” the International Air Transport Association (IATA) proposes Near Field Communication (NFC) and a single token concept to be enablers for future digital travel. NFC is a wireless technology commonly utilized in Portable Electronic Devices (PEDs) and contactless smart cards. It is characterized by the following two attributes: a tangible user interface and secured short range communication. While manufacturers are currently adapting PED settings to enable NFC in the flight mode, the integration and use of this technology in aircraft cabins still remains a challenge. There are no explicit qualification guidelines for electromagnetic compatibility (EMC) testing in an aircraft environment available and there is a lack of a detailed characterization of NFC equipped PEDs.
2017-09-19
Journal Article
2017-01-2018
Won Il Jung, Larry Lowe, Luis Rabelo, Gene Lee, Ojeong Kwon
Operator training using a real weapon in a real-world environment is risky, expensive, time-consuming, and restricted to the given environment. The simulator, or a virtual simulation, is usually employed to solve these limitations. As the operator is trained to maximize weapon effectiveness, the effectiveness-focused training can be completed. However, the training was completed in limited scenarios without guidelines to optimize the weapon effectiveness for an individual operator, thus the training will not be effective with a bias. For overcoming this problem, we suggest a methodology on guiding effectiveness-focused training of the weapon operator using big data and Virtual and Constructive (VC) simulations. Big data, which includes structured, unstructured, and semi-structured types, are generated by VC simulations under a variety of scenarios.
2017-09-19
Technical Paper
2017-01-2019
Rakshath G Poojary, Mohammed Ali Jouhar, Abubakar K
Human Powered Helicopter which uses man power to operate. The main aim of this paper is to design commercially available vehicle for an Adventure Sporting under 5-6 lakh Indian Rupees. This structural design is extremely lightweight and strong. The product is designed in such a way that it can be easily assembled and dismantled for transportability and storage. We developed an aero-structural optimization scheme for rotor design, including an aerodynamic model with included ground effect prediction, finite-element analysis and integrated composite failure analysis, and a detailed weight estimation scheme. This was solely build on computer CAD models. This design includes the use of gear box to increase the output. The Aerodynamic analysis was done using CFD and BET (blade element theory-Bhramwell) in MATLAB.
2017-09-19
Journal Article
2017-01-2024
Natasha L. Schatzman, Narayanan Komerath, Ethan A. Romander
The blade crossing event of a coaxial counter-rotating rotor is a potential source of noise and impulsive blade loads. Blade crossings occur many times during each rotor revolution. In previous research by the authors, this phenomenon was analyzed by simulating two airfoils passing each other at specified speeds and vertical separation distances, using the compressible Navier-Stokes solver OVERFLOW. The simulations explored mutual aerodynamic interactions associated with thickness, circulation, and compressibility effects. Results revealed the complex nature of the aerodynamic impulses generated by upper/lower airfoil interactions. In this paper, the coaxial rotor system is simulated using two trains of airfoils, vertically offset, and traveling in opposite directions. The simulation represents multiple blade crossings in a rotor revolution by specifying horizontal distances between each airfoil in the train based on the circumferential distance between blade tips.
2017-09-19
Technical Paper
2017-01-2026
Narayanan Komerath, Shravan Hariharan, Dhwanil Shukla, Sahaj Patel, Vishnu Rajendran, Emily Hale
Our concept studies have indicated that a set of reflectors floated at high altitudes and supported by aerodynamic lift, can reduce radiant forcing into the atmosphere. The cost of reducing the radiant forcing sufficiently to reverse the current rate of global warming, is well within the financial abilities of the world. This paper describes one of the concepts for such reflectors. The basic element of a reflector array is a rigidized reflector sheet towed behind and above a solar-powered, distributed electric-propelled fixed flying wing aircraft. The altitude rises above 30,480 meters (100,000 feet) in the daytime and does not sink below 28,288 meters (60,000 feet or Flight Level FL60) at night. While the reflector sheet easily supports its own weight with very small lift coefficient, the skin friction and induced drag components are large.
2017-09-19
Technical Paper
2017-01-2047
Tyler Vincent, Joseph Schetz, K. Lowe
Analysis and design of total temperature probes for accurate measurements in hot, high-speed flows remains a topic of great interest in aerospace propulsion and a number of other engineering areas. Despite an extensive prior literature on the subject, prediction of error sources from convection, conduction and radiation is still an area of great concern. For hot-flow conditions, the probe is normally mounted in a cooled support, leading to substantial axial conduction along the length of the probe. Also, radiation plays a very important role in most hot, high-speed conditions. One can apply detailed computational methods for simultaneous convection, conduction and radiation heat transfer, but such approaches are not suitable for rapid, routine analysis and design studies. So, there is still a place for approximate methods, and that is the subject of this paper.
2017-09-19
Technical Paper
2017-01-2052
K Friedman, G Mattos, K Bui, J Hutchinson, A Jafri, J Paver PhD
Aircraft seating systems are evaluated utilizing a variety of impact conditions and selected injury measures. Injury measures like the Head Injury Criterion (HIC) are evaluated under standardized conditions using anthropometric dummies such as those outlined in 14 CFR part 25. An example would be a dummy seated in an upright position held with a two point belt decelerated from an impact speed and allowed to engage components that are in front of the dummy. Examples of head contact surfaces would include video monitors, a wide range of seat back materials, and airbags from which the HIC and other injury measures can be calculated. Other injury measures, such as Nij, are also of interest and can be measured with the Hybrid III dummy as well. A minimum deceleration pulse is defined as part of the regulations for a frontal impact. In this study the effect of variations in decelerations that meet the requirements is considered.
2017-09-19
Technical Paper
2017-01-2054
K Friedman, G Mattos, K Bui, J Hutchinson, A Jafri, J Paver
Aircraft seating systems are evaluated utilizing a variety of impact conditions and selected injury measures. Injury measures like the Head Injury Criterion (HIC) are evaluated under standardized conditions using anthropometric dummies such as those outlined in 14 CFR part 25. An example would be a dummy seated in an upright position held with a two point belt decelerated from an impact speed and allowed to engage components that are in front of the dummy. Examples of head contact surfaces would include video monitors, a wide range of seat back materials, and airbags from which the HIC and other injury measures can be calculated. Other injury measures, such as Nij, are also of interest and can be measured with the Hybrid III dummy as well. It has been shown that the friction between the head form and contact surfaces can affect the test results obtained in other safety applications.
2017-09-19
Technical Paper
2017-01-2115
Gilberto Burgio, Leonardo Mangeruca, Alberto Ferrari, Marco Carloni, Virgilio Valdivia-Guerrero, Laura Albiol-Tendillo, Parithi Govindaraju, Marcel Gottschall, Olaf Oelsner, Sören Reglitz, Jann-Eve Stavesand, Andreas Himmler, Lionel Yapi
This paper presents a demonstrator implemented in the project MISSION (Modelling and Simulation Tools for Systems Integration on Aircraft). This is a collaborative project being developed under the European Union Clean Sky 2 Program, a public-private partnership bringing together aeronautics industrial leaders and public research organizations based in Europe. The provision of integrated modelling, simulation, and optimization tools to effectively support all stages of aircraft design remains a critical challenge in the aerospace industry. In particular the high level of system integration that is characteristic of new aircraft designs is dramatically increasing the complexity of both design and verification. Simultaneously, the multiphysics interactions between structural, electrical, thermal, and hydraulic components have become more significant as the systems become increasingly interconnected.
2017-09-19
Technical Paper
2017-01-2030
Benjamin Cheong, Paolo Giangrande, Patrick Wheeler, Pericle Zanchetta, Michael Galea
In effort to reduce environmental impact of the aerospace industry, More Electric Aircraft (MEA) concepts with electrical systems for fuel pumping, wing ice protection, environmental control systems and aircraft actuation are becoming more and more widely researched. The replacement of hydraulic actuators by motor drives for flight control surfaces is particularly attractive for maintainability, reduction in operating costs and to eliminate the hydraulic fluid. High power density of aerospace motor drives is a key factor in the successful realization of these concepts. An integrated system design approach offer optimization opportunities for further improvements in power density however the challenge lies in its multi-disciplinary modelling and the handling of numerous optimization variables or constraints that are discrete and non-linear in nature. A 4-level modelling paradigm has been proposed by multiple authors to represent a motor drive.
2017-09-19
Technical Paper
2017-01-2064
Parvez Alam M, Dinesh Manoharan, Satheesh Chandramohan, Sabarish Chakkath, Sunil MAURYA
In the present market, multiple sophisticate and expensive Thrust Test Rigs for Brushless Motors (BLDC Motor) are available making it impossible to conduct such thrust analysis on a regular and cost effective basis. Moreover the present test rigs are incapable to measure high Thrust values. This needs specialized thrust testing rig which is more expensive. This paper aims at Design & Development of the Small Scale Test Rig Setup for measurement of the thrust of any Brushless DC motor and helps in refining the Selection of motor and propeller. This is a set up based on cost efficiency factor to implement such rigs, test and for comparing the static thrust produced by the BLDC motor. The fairly simple construction contains a weighing machine, a Tachometer and a Wattmeter to measure the Thrust, RPM and the Current Drawn respectively, and provide comprehensive, accurate and efficient data coming from the BLDC Motor including the Propeller and Electronic Speed Control (ESC).
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