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Viewing 181 to 210 of 20972
2014-09-16
Technical Paper
2014-01-2164
Srikanth Gururajan, Mario Luca Fravolini, Matthew Rhudy, Antonio Moschitta, Marcello Napolitano
Abstract Recent catastrophic air crashes have shown that physical redundancy is not a foolproof option for failures on Air Data Systems (ADS) on an aircraft providing airspeed measurements. Since all the redundant sensors are subjected to the same environmental conditions in flight, a failure on one sensor could occur on the other sensors under certain conditions such as extreme weather; this class of failure is known in the literature as “common mode” failure. In this paper, different approaches to the problem of detection, identification and accommodation of failures on the Air Data System (ADS) of an aircraft are evaluated. This task can be divided into component tasks of equal criticality as Sensor Failure Detection and Identification (SFDI) and Sensor Failure Accommodation (SFA). Data from flight test experiments conducted using the WVU YF-22 unmanned research aircraft are used. Analytical redundancy is provided through a least squares modeling based approach and an extended Kalman filter approach to handle the Sensor Failure Accommodation (SFA) task.
2014-09-16
Technical Paper
2014-01-2166
Yamina Boughari, Ruxandra Botez, Georges Ghazi, Florian Theel
Abstract The main goal of this flight control system is to achieve good performance with acceptable flying quality within the specified flight envelope while ensuring robustness for model variations, such as mass variation due to fuel burn. The Cessna Citation X aircraft linear model is presented for different flight conditions to cover the aircraft's flight envelope, on which a robust controller is designed using the H-infinity method optimized by two heuristic algorithms. The optimal controller was used to achieve satisfactory dynamic characteristics for the longitudinal and lateral stability control augmentation systems with respect to this aircraft's flying quality requirements. The weighting functions of the H-infinity method were optimised by using both genetic and differential evolution algorithms. The evolutionary algorithms gave very good results. This is the first time these algorithms have been used in this form to optimize H-infinity controllers on a business aircraft, respecting both flying quality requirements and robustness criteria as objective functions and avoiding the use of other computationally complicated algorithms.
2014-09-16
Technical Paper
2014-01-2156
Arthur V. Radun
Abstract There is a continuing need to simulate power electronic circuits that include magnetic components. It is necessary to determine the interaction of the magnetic component with the rest of the power electronic system so that a dynamic circuit model of the magnetic components including material saturation and iron losses is required. Also, the magnetic component model must be valid when the magnetic component's excitation is not sinusoidal. A dynamic magnetic circuit model derived from Maxwell's equations along with useful theorems for building circuit models from the structure of the magnetic device is reviewed. The developed circuit models are general including magnetic saturation and iron losses. Simulation results for a DC/DC converter employing a conventional gapped inductor and a gapped coupled inductor are presented.
2014-09-16
Technical Paper
2014-01-2157
Puvan Arumugam, Chris Gerada, Serhiy Bozhko, He Zhang, Weeramundage Fernando, Antonino La Rocca, Stephen Pickering
Abstract This paper describes a high-speed electrical machine for an aircraft starter-generator. A surface mounted permanent magnet machine is designed to have minimal rotor losses and a novel cooling system for the stator. An inner stator sleeve is adopted to allow for a flooded stator whilst minimizing rotor windage losses. Different slot-pole combinations are compared in view of attaining an optimal combination that provides minimum losses whilst satisfying the electromagnetic, mechanical and thermal constraints.
2014-09-16
Technical Paper
2014-01-2158
James Borg Bartolo, Chris Gerada
Abstract A 45kW, switched reluctance type, starter-generator, having a 1:4 constant power speed range has been designed as a possible candidate for a regional jet application. In the first section of this paper, a review of the major starter-generator topologies considered for the aerospace application is provided, highlighting the advantages of choosing the Switched reluctance topology for such a safety critical application. Following this, the required torque speed characteristic of the machine, along with the imposed physical constraints, in terms of cooling and outer dimensions, are also detailed. Section III provides a description of the Electromagnetic design, and challenges encountered in meeting both the low speed, peak torque node, at 8000rpm, and the high speed, high power node, at 32000rpm. The induced mechanical stresses in the rotor at such high speeds have also been evaluated and used as a material selection criterion for such a design as presented in section III. Section IV, describes the thermal model developed to estimate the radial temperature distribution within the machine, taking into account end winding phenomena and cooling fluid constraints.
2014-09-16
Technical Paper
2014-01-2159
Richard Mourn
Abstract The paper provides an introduction into IEEE-1394, AS5643 and related documents. It then explores the I/O Technology Suitability Study criteria used to originally select IEEE-1394b (Beta) as the Vehicle System Data Bus for the F-35 Joint Strike Fighter and update each criterion with new information based on more than a decade of experience and use in not only the F-35 but several other programs. Based on the suitability study criteria, the reader gains insight into how and why programs like the F-35, which implements dozens of AS5643/IEEE-1394 devices per plane, utilize AS5643/IEEE-1394 for its vehicle system network. This unprecedented use of a high speed (491.52Mb/s) serial interface on an aircraft proves the capability of AS5643/1394, and opens the door for higher bandwidth communication between the Control Computer and remote nodes. While I/O bandwidth is important, system level deterministic behavior is required for most vehicle system networks and AS5643 coupled with 1394 provides the required deterministic behavior.
2014-09-16
Technical Paper
2014-01-2182
Evan Racine, Zachary Lammers, Street Barnett, John Murphy, Quinn Leland
Abstract The purpose of this study is to set up a laboratory test apparatus to analyze aircraft flight control EMAS' electrical and thermal energy flow under transient and dynamic flight profiles. A hydraulic load frame was used to exert load to the EMA. The actuator was placed within an environmental chamber which simulates ambient temperature as function of altitude. The simulated movement or stroke was carried out by the EMA. The under test EMA's dynamic load, stroke, and ambient temperature were synchronized through a real time Labview DAQ system. Motor drive voltage, current, regenerative current, and motor drive and motor winding temperature were recorded for energy analysis. The EMA under test was subjected to both transient and holding load laid out in a test matrix. It was found that the transient missions of EMAS presented the most electric demand on the aircraft electric power supply system while holding presented the most severe thermal stress on the EMAS, where the EMAS operated at 0% efficiency and all the electric power converted to heat.
2014-09-16
Technical Paper
2014-01-2181
Christopher Ian Hill, Chris Gerada, Paolo Giangrande, Serhiy Bozhko
Abstract This paper presents the initial development of a Modelica Library for Electro-Mechanical Actuator system analysis. At present two main system components are described, these are the Power Electronic Converter and Electric Machine, although further components will be added. These models provide the user with the ability to simulate Electric Machine and Power Electronic Converter systems including physical effects, losses and fault conditions. Established modelling programs such as Saber and MATLAB SimPowerSytems are often unable to provide all the aspects required to accurately simulate real systems in an easy to use, flexible manner. Therefore this paper shows how Modelica has been used to create versatile models able to simulate many practical aspects such as Power Electronic Converter losses and Power Electronic Converter faults, Electric Machine losses and Electric Machine faults. Examples are included in order to demonstrate the use of these models within a variety of systems including an Electro-Mechanical Actuator.
2014-09-16
Technical Paper
2014-01-2187
Teresa Donateo, Maria Grazia De Giorgi, Antonio Ficarella, Elisabetta Argentieri, Elena Rizzo
Abstract The present study aims at the implementation of a Matlab/Simulink environment to assess the performance (thrust, specific fuel consumption, aircraft/engine mass, cost, etc.) and environmental impact (greenhouse and pollutant emissions) of conventional and more electric aircrafts. In particular, the benefits of adopting more electric solutions for either aircrafts at given missions specifications can be evaluated. The software, named PLA.N.E.S, includes a design workflow for the input of aircraft specification, kind of architecture (e.g. series or parallel) and for the definition of each component including energy converter (piston engine, turboprop, turbojet, fuel cell, etc.), energy storage system (batteries, super-capacitors), auxiliaries and secondary power systems. It is also possible to setup different energy management strategies for the optimal control of the energy flows among engine, secondary equipment and storage systems during the mission. The tool is designed to be integrated with a multi-objective optimization environment.
2014-09-16
Technical Paper
2014-01-2186
Neno Novakovic
Abstract Since the early 1970s, when microprocessors became commercially available, they quickly became a common part of all aircraft control and indication systems. With an ever-increasing number of microprocessor-based airborne applications, safety regulations and software standards like RTCA DO-178 evolved, demanding rigorous requirements and processes for software development, testing, life cycle, and certification. Over the years, as development of aerospace software applications increased, engineering costs of development and product certification costs exponentially increased, having a significant impact on the market. Landing Gear Actuation system is one of many aircraft systems whose control functions are based on microprocessors and software application. Considering that Landing Gear Actuation control algorithm can be defined in a form of the State Machine, this article intends to demonstrate that such controller can be realized as wired logic hardware, without software implementation.
2014-09-16
Technical Paper
2014-01-2189
Andrew Slippey, Michael Ellis, Bruce Conway, Hyo Chang Yun
Abstract Carbon fiber reinforced polymer (CFRP) composite material is an attractive structural material in applications where mass is critical. The carbon fiber matrix provides strength comparable to steel with only 25% of the density. The CFRP sheet can often also be made thinner than metal with similar mechanical properties, further increasing the mass savings. However, thermal challenges have arisen with the increased use of composites. In the area of electronics enclosures, traditional metal structures conduct and spread heat over large surfaces, but composites act as insulation. Heat generated by components causes internal temperatures to rise and has detrimental impact on the performance and reliability of the electronics. A method is proposed and tested that utilizes constant conductance heat pipes (CCHPs) that penetrate through the CFRP walls. The CCHPs are capable of transporting significant heat energy through a limited cross-section with a minimal temperature penalty. CCHPs are passive, two-phase, thermal transport devices which have extremely high effective thermal conductivities on the order of thousands of W/m-K.
2014-09-16
Technical Paper
2014-01-2188
Riko Bornholdt, Frank Thielecke
Abstract Due to a shift of the major aviation concerns to focus on enhancements of the successful programs instead of pushing their successors, the need for new methodologies for aircraft system architecture design emerges. Challenging the existing requirements and reconsidering the functions and their allocation could help to dissolve the system specific development paradigm and lead to beneficial architecture concepts. To help understand the mechanisms and boundary conditions of developing fault-tolerant systems, the first part of the paper gives an overview of the successive process of architecture design. The significant architectural design decisions and the concurrent safety assessment process are discussed. One crucial step in the design space exploration of future aircraft system architectures is the allocation of the consumers to the available power sources. Within the paper a methodology for the optimization of the power allocation for flight control systems is proposed. With this methodology the evaluation of a large amount of architecture permutations on the basis of a preliminary system safety assessment regarding multiple top failure events is possible in a short time period.
2014-09-16
Technical Paper
2014-01-2169
Yves C.J. Lemmens, Tuur Benoit, Rob De Roo, Jon Verbeke
Vives College University and Kulab (KU Leuven University campus Ostend) in Belgium are undertaking an aeronautical research program about the development of a new Unmanned Aerial Vehicle (UAV). Since the UAV is completely electrically powered, the analysis of the energy management of the integrated electrical system was critical to the development of the UAV. LMS, A Siemens Business, is involved in the project to support the development of a multi-physics simulation model for electro-thermal analysis of the aircraft. This paper reports on the subsequent investigation of integrating the detailed electrical system model for a Pilot-in-the-Loop simulation. In order to perform this simulation, the model of the electrical system was converted into a real-time simulation model. The aim was to perform more realistic flight simulations to evaluate the performance of the aircraft before its first flight by taking into account the electrical system's behavior. Furthermore, the behavior of the electrical system can be directly assessed during and after the Pilot-in-the-Loop tests.
2014-09-16
Technical Paper
2014-01-2174
Nicholas Ernest, Kelly Cohen, Corey Schumacher, David Casbeer
Abstract Looking forward to an autonomous Unmanned Combat Aerial Vehicle (UCAV) for future applications, it becomes apparent that on-board intelligent controllers will be necessary for these advanced systems. LETHA (Learning Enhanced Tactical Handling Algorithm) was created to develop intelligent managers for these advanced unmanned craft through the novel means of a genetic cascading fuzzy system. In this approach, a genetic algorithm creates rule bases and optimizes membership functions for multiple fuzzy logic systems, whose inputs and outputs feed into one another alongside crisp data. A simulation space referred to as HADES (Hoplological Autonomous Defend and Engage Simulation) was created in which LETHA can train the UCAVs intelligent controllers. Equipped with advanced sensors, a limited supply of Self-Defense Missiles (SDM), and a recharging Laser Weapon System (LWS), these UCAVs can navigate a pre-defined route through the mission space, counter enemy threats, and destroy mission-critical targets.
2014-09-16
Technical Paper
2014-01-2176
Niloofar Rashidi Mehrabadi, Bo Wen, Rolando Burgos, Dushan Boroyevich, Chris Roy
Abstract The development of the concepts, terminology and methodology of verification and validation is based on practical issues, not the philosophy of science. Different communities have tried to improve the existing terminology to one which is more comprehensible in their own field of study. All definitions follow the same concept, but they have been defined in a way to be most applicable to a specific field of study. This paper proposes the Verification, Validation, and Uncertainty Quantification (VV&UQ) framework applicable to power electronic systems. Although the steps are similar to the VV&UQ frameworks' steps from other societies, this framework is more efficient as a result of the new arrangement of the steps which makes this procedure more comprehensible. This new arrangement gives this procedure the capability of improving the model in the most efficient way. Since the main goal of the VV&UQ process is to quantitatively assess the confidence in modeling and simulation, the second part of this paper focuses on uncertainty quantification.
2014-09-16
Technical Paper
2014-01-2173
Aurelie Beaugency, Marc Gatti, Didier Regis
Abstract Since 2000, avionics is facing several changes, mostly driven by technological improvements in the electronics industry and innovation requirements from aircraft manufacturers. First, it has progressively lost its technological leadership over innovation processes. Second, the explosion of the electronics consumer industry has contributed to shorten even more its technology life cycles, and promoted the use of COTS. Third, the increasing complexity of avionics systems, which integrate more and more functions, have encouraged new players to enter the market. The aim of this article is to analyze how technological changes can affect the competitiveness of avionics firms. We refer to criticality levels as a determinant of the market competitiveness. Certification processes and costs could stop new comers to bring innovations from the consumer electronics industry and protects traditional players. The study will compare three avionics systems regarding their patent dynamics since 1980: flight controls, Integrated Modular avionics and Head-Up Displays.
2014-09-16
Technical Paper
2014-01-2175
Jay Wilhelm, Joseph Close, Wade Huebsch
A Hybrid Projectile (HP) is a ballistically launched round that transforms into an Unmanned Aerial Vehicle (UAV) at a designated point during flight. Aerodynamic control surfaces and associated control laws were sought that would extend the projectile's range using body lift and include guidance for a selected point of impact. Several challenges were encountered during the modification of an existing projectile, in this case a 40mm round, to achieve range extension and controllability. The control surfaces must be designed to allow for de-spin, controllability, and natural static stability. Also, a control system with laws and guidance relationships between heading, pitch or glide rate, and the associated aerodynamic surface movements needed to be developed. The designed aerodynamic surfaces, external ballistics, and control methods developed were modeled in a projectile flight simulator built in MATLAB. The base model was an M781 practice round and the aerodynamic coefficients and mass data were found in literature.
2014-09-16
Technical Paper
2014-01-2132
Prashant Vadgaonkar, Ullas Janardhan, Adishesha Sivaramasastry
Abstract Performance of Avionics systems is dictated by the timely availability and usage of critical health parameters. Various sensors are extensively used to acquire and communicate the desired parameters. In today's scenario, sensors are hardwired. The number of sensors is growing due to automation which increases the accuracy of intended Aircraft functions. Sensors are distributed all over the Aircraft and they are connected through wired network for signal processing and communication. LRUs (Line Replaceable Unit) which are integrating various sensors also use a wired approach for communication. The use of a wired network approach poses challenges in terms of cable routing, stray capacitances, noise, mechanical structure and added weight to the structure. The weight of cables contributes significantly to the overall weight of the aircraft. As the weight of Aircraft increases, the required fuel quantity also increases. The Key driver for Airline operational cost is fuel. Fuel quantity is a direct function of weight.
2014-09-16
Technical Paper
2014-01-2129
Vincent Metzger, Douglas Parker, Alain Philippe, Sebastien Claudot
Abstract Fiber optic physical contact connection technology has been used with multimode fiber in civilian aircraft for over 30 years with very good proven reliable performance. The extensive use of singlemode fiber (SMF) in FTTx Telecom market rollouts speeds up the development of passive optical components which significantly decreases the cost, expands capability and increases the reliability level of singlemode components. SMF transmission seems mandatory for future applications even in mil-aero and other harsh environment applications due to increased data rate requirements and new sensors applications. In harsh environment applications, is it realistic to use SMF with cores that are 30 times smaller in area compared to multimode fiber (MMF) when highly exposed to contamination? The present paper presents a technology of beam expansion interconnection that mixes a physical contact (PC) with an expanded optical surface. The optical connector brings together benefits of both technologies resulting in a reliable connection requiring low maintenance for SMF fiber optic applications.
2014-09-16
Technical Paper
2014-01-2127
Karl Strauss
Abstract “Today's electronic components rely on principles of physics and science with no manufacturing precedence and little data on long term stability and reliability.” [1] Yet many are counting on their reliable performance years if not decades into the future, sometimes after being literally abandoned in barns or stored neatly in tightly sealed bags. What makes sense? To toss everything away, or use it as is and hope for the best? Surely there must be a middle ground! With an unprecedented number of missions in its future and an ever-tightening budget, NASA faces the daunting task of doing more with less. One proven way for a project to save money is to use already screened and qualified devices from the spares of its predecessors. But what is the risk in doing so? How can a project reliably count on the value of spare devices if the risk of using them is not, in itself, defined? With hundreds of thousands of devices left over from previous missions, the parts bins of NASA hold a wealth of electronic components, (possibly) ready for use many years after their production.
2014-09-16
Technical Paper
2014-01-2125
Janice Meraglia, Mitchell Miller
Abstract Counterfeit items can be viewed as the by-product of a supply chain which has been compromised. While many industries are impacted, certain types of products can mean the difference between life and death. Electronics are of special interest, however, mechanical parts can also have dire consequences. The point is that the counterfeiting community is very diverse. The business model is fluid and unrestricted. Electronics today…hardware tomorrow. All of this leads to the need for an authentication platform that is agnostic to product. Most supply chains would benefit from a technical way to have assurance of authenticity - a benefit that could be shared by all. A comprehensive marking program, such as SigNature DNA, offers value to all supply chain participants as outlined below: Manufacturers will have the ability to effectively monitor their legacy components Authorized distributors will have an absolute way to verify and accept returns Defense contractors and agencies will have forensically authentic and traceable inventory at their disposal End users will have the power to authenticate stock to the component level
2014-09-16
Technical Paper
2014-01-2117
Michael L. Zierolf, Thomas Brinson, Andrew Fleming
Abstract Recent emphasis on optimization of engine technologies with ancillary subsystems such as power and thermal management has created a need for integrated system modeling. These systems are coupled such that federated design methods may not lead to the most synergetic solution. Obtaining an optimal design is often contingent on developing an integrated model. Integrated models, however, can involve combining complex simulation platforms into a single system of systems, which can present many challenges. Model organization and configuration control become increasingly important when orchestrating various models into a single simulation. Additionally, it is important to understand such details as the interface between models and signal routing to ensure the integrated behavior is not contaminated or biased. This paper will present some key learnings for model integration to help alleviate some of the challenges with system-based modeling.
2014-09-16
Technical Paper
2014-01-2150
Martin Bradish, Obed Sands, Ted Wright, Casey Bakula, Daniel Oldham, William Ivancic, Michael Lewis, Joseph Klebau, Nicholas Tollis, Andrew Jalics
Abstract This paper summarizes the Power, Avionics and Software (PAS) 1.0 subsystem integration testing and test results that occurred in August and September of 2013. This paper covers the capabilities of each PAS assembly to meet integration test objectives for non-safety critical, non-flight, non-human-rated hardware and software development. This test report is the outcome of the first integration of the PAS subsystem and is meant to provide data for subsequent designs, development and testing of the future PAS subsystems. The two main objectives were to assess the ability of the PAS assemblies' to exchange messages and to perform audio tests of both inbound and outbound channels. This paper describes each test performed, defines the test, the data, and provides conclusions and recommendations.
2014-09-16
Technical Paper
2014-01-2148
Jon Hagar
Abstract System testing can, in part, be defined as the application of concepts as an attempt to demonstrate that the implementation does not meet its intended use. Unfortunately, some industry verification test efforts only show that a system meets requirements which while necessary, are not sufficient to fully address a product's system-software testing. Managers, engineers, and testers may not be familiar with the wide variety of test concepts, approaches, and standards available for system-software testing-many of which can save projects money and effort in the long run. Newer software test standards and advanced techniques can offer a wealth of knowledge and improvement opportunities for software products. This paper offers a review of emerging software test concepts and standards in which teams will find potential value toward their improvement efforts including: Math-based techniques which apply combinatorial, statistical, Design of Experiments (DOE), or domain-based concepts Attack-based testing which focuses on common industry error taxonomies Independent model-based testing using tools and standards New standards-driven testing to address verification and validation (V&V), testing, and documentation.
2014-09-16
Technical Paper
2014-01-2146
Rudolf Neydorf, Sergey Novikov, Nikita Kudinov
Abstract Airship designers research application versions of systems with several ballonets for adjustment of airship roll and/or pitch as a whole. This requires effective automatic status management of each separate ballonet. But multi-ballonet system control issue encounters the absence of industrially measurable variables of each separate ballonet status. Thus status control issue of the system becomes uncertain. The fact requires the issue studying and shaping new scientific and technical solutions. This publication represents research results implying that fairly simple implementation and effective result can be achieved by application of fuzzy control concept. Its application is built on generating the representative quantity of fuzzy production rules. They are based on present set evaluation of known parameters and measured variables. This results in fuzzy but meaningful image of ballonet system status and airship as a whole. Thus achieving fairly good control over multi-ballonet system.
2014-09-16
Technical Paper
2014-01-2139
Serhiy Bozhko, Seang Shen Yeoh, Fei Gao, Tao Yang, Christopher Hill
Abstract The paper reports the control design for an aircraft electric starter-generator system based-on high-speed permanent magnet machine operated in a flux-weakening mode and controlled by an active front-end rectifier. The proposed system utilizes advances of modern power electronics allowing the use of novel machine types and the introduction of controlled power electronics into the main path of energy flow. The paper focuses on control design for such system and includes development of flux weakening control of high-speed permanent magnet machine and droop control of the system output dc-link current. The achieved analytical design results and the expected system performance are confirmed by time-domain simulations.
2014-09-16
Technical Paper
2014-01-2113
Fei Gao, Serhiy Bozhko, Greg Asher
Abstract Stability is a great concern for the Electrical Power System (EPS) in the More Electric Aircraft (MEA). It is known that tightly controlled power electronic converters and motor drives may behave as constant power loads (CPLs) which may produce oscillations and cause instability. The paper investigates the stability boundaries for dc multi-source EPS under different power sharing strategies. For each possible strategy the corresponding reduced-order models are derived. The impedance criterion is then applied to study the EPS stability margins and investigates how these margins are influenced by different parameters, such as main bus capacitance, generator/converter control dynamics, cabling arrangements etc. These results are also illustrated by the root contours of reduced-order EPS models. Theoretical results achieved in the paper are confirmed by the time-domain simulations.
2014-09-16
Technical Paper
2014-01-2115
Brian C. Raczkowski, Benjamin Loop, Jason Wells, Eric Walters, Oleg Wasynczuk, Sean Field, Jason Gousy
Abstract Future more electric aircraft (MEA) architectures that improve electrical power system's (EPS's) source and load utilization will require advance stability analysis capabilities. Systems are becoming more complex with bidirectional flows from power regeneration, multiple sources per channel and higher peak to average power ratios. Unknown load profiles with large transients complicate common stability analysis techniques. Advancements in analysis are critical for providing useful feedback to the system integrator and designers of multi-source, multi-load power systems. Overall, a framework for evaluating stability with large displacement events has been developed. Within this framework, voltage transient bounds are obtained by identifying the worst case load profile. The results can be used by system designers or integrators to provide specifications or limits to suppliers. Subsystem suppliers can test and evaluate their design prior to integration and hardware development. By identifying concerns during the design phase, a more streamlined approach to hardware development can save on rework, integration delays and cost.
2014-09-16
Technical Paper
2014-01-2111
Shweta Sanjeev, Goutham Selvaraj, Patrick Franks, Kaushik Rajashekara
Abstract The transition towards More Electric Aircraft (MEA) architectures has challenges relating to integration of power electronics with the starter generator system for on-engine application. To efficiently operate the power electronics in the hostile engine environment at high switching frequency and for better thermal management, use of silicon carbide (SiC) power devices for a bi-directional power converter is examined. In this paper, development of a 50 kVA bi-directional converter operating at an ambient temperature of about 2000C is presented. The design and operation of the converter with details of control algorithm implementation and cooling chamber design are also discussed.
2014-09-16
Technical Paper
2014-01-2101
Joseph Dygert, Melissa Morris, Patrick Browning
Abstract The high demand for traditional air traffic as well as increased use of unmanned aerial systems (UAS) has resulted in researchers examining alternative technologies which would result in safer, more reliable, and better performing aircraft. Active methods of aerodynamic flow control may be the most promising approach to this problem. Research in the area of aerodynamic control is transitioning from traditional mechanical flow control devices to, among other methods, plasma actuators. Plasma actuators offer an inexpensive and energy efficient method of flow control. Dielectric Barrier Discharge (DBD), one of the most widely studied forms of plasma actuation, employs an electrohydrodynamic (EHD) device which uses dominant electric fields for actuation. Unlike traditional flow control methods, a DBD device operates without moving components or mass injection methods. Publications discussing the optimization of DBD flow control versus a single variable such as gap width, voltage, dielectric constant, etc., have been widely published, and instigated a 2003 paper published by the IEEE-DEIS-EHD Technical Committee titled “Recommended International Standard for Dimensionless Parameters Used in Electrohydrodynamics.”
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