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Turbulence estimation by eddy dissipation rate at low-altitudes using UAV in-situ data
(Brno University of Technology, Institute of Solid Mechanics, Mechatronics and Biomechanics, 2024-05-14) Balážová, Renáta; Ferrari, Simone; Hlinka, Jiří; Santus, Alessandro
Deploying Unmanned Aerial Vehicles (UAVs) into routine operation requires accurate hyperlocal data. The requirements are set with a significant difference compared to the meteorological information and forecasts that have been sufficient until now. Several challenges need to be solved for the safe operation of UAVs. One of the most significant weaknesses of current meteorological information is turbulence and its detection. This article is focused on the low-altitudes turbulence detection using multicopters and their estimate processed by eddy dissipation rate. A low-cost low-weight method has been identified and will be tested on the field. Eventually, a first attempt to define a minimum safety distance from buildings for the UAVs, depending on building size and wind speed, is investigated via numerical simulations.
IMPLEMENTATION STUDY OF A PASSIVE SAFETY FEATURE IN THE RESCUE SYSTEMS OF SMALL AIRCRAFTS
(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.
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.
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.
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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