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Recent Submissions

Now showing 1 - 5 of 20
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    (VILNIUS GEDIMINAS TECH UNIV, 2023-10-13) Hájek, Tomáš; Grim, Robert; Popela, Robert
    Article History: Abstract. The aim of this paper is to evaluate the feasibility of implementation of a passive safety feature in the form of an under-fuselage airbag in the rescue systems of small aircraft. The paper presents a multidisciplinary approach for the viability of the implementation. It presents the development of mathematical model for airbag performance analysis. The model is validated against the experimental data to account for various simplifications. Validated mathematical model is used to design a full-scale airbag for the chosen airplane to perform in the designed range. Weight penalty for increased safety is determined.
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    Additive manufacturing capabilities for heat switch technology: Key challenges & knowledge gaps
    (EUCASS association, 2022-09-28) Mašek, Jakub; Löffelmann, František; Popela, Robert; Kubík, Petr; Šebek, František; Koutný, Daniel; Malý, Martin; Pantělejev, Libor; Pambaguian, Laurent
    The paper is to provide an overview of the key challenges and knowledge gaps in additive manufacturing of metals applied to two parts of a novel heat switch technology – a Baseplate and a Flexible thermal structure. Additive design, optimization and manufacturing capabilities as well as quality of produced parts were investigated. The key challenge was to manufacture bio-inspired structure without internal supports and assure 190 surfaces to be in a contact at the same time for efficient heat transfer. Finally, modern trends in additive as multi-material design and manufacturing or effect of defects are discussed for further evolution of parts.
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    Modifications of a simple I-beam and its effects on the stress state
    (Taylor & Francis, 2016-12-20) Cejpek, Jakub; Juračka, Jaroslav
    The motivation for this work is a desire for a deeper understanding of the structural failures in a composite glider wing, which has been tested in the laboratories of the Institute of Aerospace Engineering, Faculty of Mechanical Engineering, Brno University of Technology. To understand the causes of the encountered failures, one has to consider the effects of all the stages in the design, manufacturing and testing of the wing. This paper focuses only on the design stage. The presented facts were obtained from a finite element analysis. The geometry used for the analysis is that of the tested specimens. This allows validating the results by the comparison of the deformation and strains measured during the laboratory tests. The analysis starts with a simple I-beam loaded by three-point-bending. In the next step a cantilever is added. Several more modifications follow, changing the I-beam to the wing. The case evaluation considers the interaction between normal (material direction 1) and inter-laminar shear stresses in the upper flange. The goal of this paper is to quantify the effect of each design change in the wing structure and loading on the stress plane 1-31.
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    Bird strike as a threat to aviation safety
    (Elsevier, 2021-12-08) Juračka, Jaroslav; Chlebek, Jiří; Hodaň, Viktor
    This article discusses air safety and the importance of safety studies as an effective tool for detecting safety risks. It has to provide a brief overview of Aviation Safety Hazards with a detailed look at the danger of collision of aircraft with birds. There is a technical description of course of events in the bird ingestion into the engine flying aircraft in the particular case. The final chapter generally deals with ways to minimize the risk.
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    Simulation of a maneuvering aircraft using a panel method
    (Czech Technical University in Prague, 2021-04-30) Schoř, Pavel; Kouřil, Martin; Daněk, Vladimír
    We present a method for numerical simulations of a maneuvering aircraft, which uses a first-order unsteady panel method as the only source of aerodynamic forces and moments. By using the proposed method, it is possible to simulate a motion of an aircraft, while the only required inputs are geometry and inertia characteristics, which significantly reduces the time required to start the simulation. We validated the method by a comparison of recordings of flight parameters (position, velocities, accelerations) from an actual acrobatic flight of a glider and the results obtained from the simulations. The simulation was controlled by deflections of control surfaces recorded during the actual flight. We found a reasonable agreement between the experimental data and the simulation. The design of our method allows to evaluate not only the integral kinematic quantities but also instant local pressure and inertia loads. This makes our method useful also for a load evaluation of an aircraft. A significant advantage of the proposed method is that only an ordinary workstation computer is required to perform the simulation.