287 research outputs found

    12th EASN International Conference on "Innovation in Aviation & Space for opening New Horizons"

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    Epoxy resins show a combination of thermal stability, good mechanical performance, and durability, which make these materials suitable for many applications in the Aerospace industry. Different types of curing agents can be utilized for curing epoxy systems. The use of aliphatic amines as curing agent is preferable over the toxic aromatic ones, though their incorporation increases the flammability of the resin. Recently, we have developed different hybrid strategies, where the sol-gel technique has been exploited in combination with two DOPO-based flame retardants and other synergists or the use of humic acid and ammonium polyphosphate to achieve non-dripping V-0 classification in UL 94 vertical flame spread tests, with low phosphorous loadings (e.g., 1-2 wt%). These strategies improved the flame retardancy of the epoxy matrix, without any detrimental impact on the mechanical and thermal properties of the composites. Finally, the formation of a hybrid silica-epoxy network accounted for the establishment of tailored interphases, due to a better dispersion of more polar additives in the hydrophobic resin

    A Review of Current Research Trends in Power-Electronic Innovations in Cyber-Physical Systems.

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    In this paper, a broad overview of the current research trends in power-electronic innovations in cyber-physical systems (CPSs) is presented. The recent advances in semiconductor device technologies, control architectures, and communication methodologies have enabled researchers to develop integrated smart CPSs that can cater to the emerging requirements of smart grids, renewable energy, electric vehicles, trains, ships, internet of things (IoTs), etc. The topics presented in this paper include novel power-distribution architectures, protection techniques considering large renewable integration in smart grids, wireless charging in electric vehicles, simultaneous power and information transmission, multi-hop network-based coordination, power technologies for renewable energy and smart transformer, CPS reliability, transactive smart railway grid, and real-time simulation of shipboard power systems. It is anticipated that the research trends presented in this paper will provide a timely and useful overview to the power-electronics researchers with broad applications in CPSs.post-print2.019 K

    Resilient operation of DC microgrid against FDI attack : a GRU based framework

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    DC microgrid is the most susceptible to cyber-attacks as the communication channel is involved for the implementation of the secondary controller. Accordingly, the false data are injected into the transmitted data (i.e., DC bus voltage) and it may lead to deteriorating the system performance. To address these issues, the gated recurrent unit (GRU) based mechanism is presented to eliminate the false data injection (FDI) attack for the resilient operation of the DC microgrid. The presented GRU-based framework is divided into two parts: 1) estimation strategy: an offline-trained GRU based network is employed herein for online evaluation of the actual DC bus voltage, and 2) mitigation strategy: GRU based trained network is exploited herein with an amalgamation of the proportional-integral (PI) controller to counteract the malicious cyber-attack. The presented GRU-based framework has several advantages such as ease of implementation and computationally efficient, unlike state-of-art methods. The sensitivity analysis is investigated herein to validate the effectiveness of the presented GRU-based framework over state-of-art techniques. Simulation results show satisfactory performance under manifold operating scenarios such as bias injection attack and time-varying attack. In addition, the quantitative and qualitative comparative performances are performed herein to demonstrate the efficacy of the presented framework

    The Enabling Technologies for a Quasi-Zero Emissions Commuter Aircraft

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    The desire for greener aircraft pushes both academic and industrial research into developing technologies, manufacturing, and operational strategies providing emissions abatement. At time of writing, there are no certified electric aircraft for passengers’ transport. This is due to the requirements of lightness, reliability, safety, comfort, and operational capability of the fast air transport, which are not completely met by the state-of-the-art technology. Recent studies have shown that new aero-propulsive technologies do not provide significant fuel burn reduction, unless the operational ranges are limited to short regional routes or the electric storage capability is unrealistically high, and that this little advantage comes at increased gross weight and operational costs. Therefore, a significant impact into aviation emissions reduction can only be obtained with a revolutionary design, which integrates disruptive technologies starting from the preliminary design phase. This paper reviews the recent advances in propulsions, aerodynamics, and structures to present the enabling technologies for a low emissions aircraft, with a focus on the commuter category. In fact, it is the opinion of the European Community, which has financed several projects, that advances on the small air transport will be a fundamental step to assess the results and pave the way for large greener airplanes

    Assessing UAM emergency procedures in existing or new heliports

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    With the rising interest from big investors and manufacturers in UAM solutions, many vehicle prototypes and ground infrastructure designs are beginning to appear and being tested in real-world scenarios. This mode of air transportation could be a game-changer if the different milestones are achieved. While there are many challenges to be covered, from noise pollution to airspace management, safety is probably one of the main elements to be assessed. And while much effort has been given into designing and promoting UAM vehicles, little research has been published or conducted about safety considerations. This study provides with a discussion on different findings related to safety based on a root cause analysis of reported and documented helicopter accidents involving similar environments and conditions to those UAM will face. By assessing these hazards in similar VTOL aircraft such as helicopters, an extrapolation to UAM vehicles is made for different types of vehicles, depending on their characteristics and performance capabilities observed in various prototypes. The analysis is divided in two main parts. The first part focuses on the different occurrences involved in the accidents, following the CICTT standard definitions for reporting aviation accidents and incidents. The second part goes deeper and analyses the causes involved that lead to those occurrences, and how these could apply to UAM vehicles. The discussion considers the identified hazards in different levels, depending on factors such as human presence and automation, and their impact on criticality, prevention and mitigation. The overall study provides with some guidelines on safety issues that are considered relevant for future research in the field of UAM, as well as for the future standardization of the necessary elements to implement and regulate these systems in urban centers
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