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Open access

Sándor Bodzás

Abstract

The spur gear is widely used in many types of machines and appliances that is why the research of the connection analysis of them (Tooth Contact Analysis, TCA) is very important because of the development of these gears. The TCA analysis is a complex task because the mathematical description, the CAD modelling process, the overall designing process, the manufacturing process of the gears and the definition of the mechanical parameters have to be known. After the gear designing process the gear pairs have to be analysed by TCA method to determine the typical dimension of the mechanical parameters in case of given load. Knowing of the result we can reason for the appropriate gear geometry of the given construction and working conditions.

Open access

Ēriks Ozoliņš, Ilmārs Ozoliņš and Līga Ramāna

Abstract

The article describes the impact of the gas turbine engine low-pressure turbine blade shroud shelf on the blade profile stress position. Attention is focused directly on the impact of the location of the gravity centre of the shroud shelf on blade stress distribution at the three most critical points of the profile. The paper describes the details of the calculation and the required expressions provided, as well as the results of the calculation example with clear graphical dependencies.

Open access

Andrii Grekhov, Vasil Kondratiuk and Svitlana Ilnitska

Abstract

Original models of RPAS communication channels based on IEEE 802.11b Standard, including both Base Station transmission within the Radio Line of Sight, and through the satellite using Beyond Radio Line of Sight, were built. Dependencies of the Bit Error Rate on the Signal-Noise Ratio for different payload data rates were obtained. Transponder nonlinearity and Base Station antenna diameter impact were analysed.

Open access

Juris Maklakovs, Jevgēnijs Tereščenko and Vladimirs Šestakovs

Abstract

In the field of security in transport distinguish risks related to flight safety and aviation security. Safety of flights is ensured through the reliability of aviation equipment and the qualification of the personnel who services and operates it, aviation security is a condition of protection from illegal interference in its activity. Risk management in civil aviation in the field of security is a relatively new direction of activity. Deep research in this area began only at the beginning of the XXI century. It is quite difficult to use the existing experience of risk management, accumulated in other spheres, as civil aviation has significant features. Various methods and schemes can be used to assess risks. The article discusses various options for predicting risks using the “event tree” and “risk factor tree” methods.

Open access

Dmitrijs Goreļikovs, Margarita Urbaha, Dmitry Nedelko and Jonas Stankunas

Abstract

Electronic Chart Display and Information Systems (ECDIS), which are used on vessels and can replace paper charts, allow to obtain and display on electronic charts information from basic and additional data sources. For the certified use of ECDIS instead of paper charts, it is necessary to ensure constant updating of Electronic Navigation Chart (ENC) data provided to vessels for use. The known visual and satellite observation systems intended for cartographic information update are costly, have low accuracy and do not allow to quickly update navigational charts in real-time mode. The stand-alone use of remotely piloted aircraft (RPA) will make it possible not only to substantially reduce costs and increase the accuracy of monitoring, but also to provide information in real-time mode.

Open access

Darula Radoslav and Sorokin Sergey

Abstract

The analytical model of a fluid filled cylindrical shell is used to analyse the wave propagation in the quarter wavelength absorbers. It has been found, that due to the strong fluid-structure interaction, the considerable wave speed reduction can be reached using a compliant shell. Thus via parametric studies, the dimensions of the absorbers are assessed to reach more efficient and compact design. Furthermore, the use of the compliant materials allows treating the fluid to be incompressible, which helps to simplify the calculations.

Open access

Kunz Jan, Čala Martin, Pikula Stanislav and Beneš Petr

Abstract

The aim of this paper is to design, implement, test and compare several tracking filtration methods for predictive maintenance of a jet engine. Based on literature review multiple possible methods are described. Appropriate ones selected for further implementation are peak filtration, coherent demodulation, Vold-Kalman filtration and order analysis. Methods are tested to meet criteria set by an aircraft manufacturer and compared using simulated signals.

Open access

Jančo Roland and Darula Radoslav

Abstract

The article deals with the contribution of Prof. Ing. Pavol Élesztős, CSc. in the field of engineering. He was born in 1948, studied and subsequently remained at the Faculty of Engineering at the Slovak University of Technology in Bratislava since 1968. Under his leadership 6 dissertation theses were defended in the study program of Applied Mechanics. He is the author of 1 monograph, co-author of 2 monographs, author of 30 reviewed scientific articles in journals, and over 250 original scientific papers published in domestic and foreign conference proceedings. Professor Élesztős is currently a Professor Emeritus and is known as a talented teacher.

This article is a celebration of prof. Ing. Stanislav Žiaran’s, CSc. contribution to the field of engineering. Born in 1948, since 1966 he studied and subsequently continued his academic career at the Faculty of Mechanical Engineering, Slovak University of Technology in Bratislava. He has supervised 2 dissertation and 42 diploma theses, which were successfully defended in the study programs Applied mechanics and Mechatronics. Prof. Žiaran is the author to 5 monographs, 9 textbooks, 13 university textbooks, 6 manuals for the engineering industry and more than 290 original scientific papers published in domestic as well as international journals and conference proceedings. He has translated of 111 ISO and EN standards, 107 research reports for practice and he is the editor of 20 peer-reviewed scientific proceedings Noise and Vibration in Practice. He also presented 16 requested lectures at world congresses abroad. Prof. Žiaran is a gifted teacher of mechanics and his students appreciate his enthusiasm and knowledge he is sharing with them.

Open access

Pleban Dariusz and Mikulski Witold

Abstract

Two test stands for determining sound insulation in the frequency range above 5 kHz were made. One consisted of two horizontally adjacent reverberation rooms and a special source of high frequency sounds and ultrasounds. The other test stand consisted of a miniaturized test chamber and a special source of ultrasounds. The paper presents results of the preliminary measurements of sound insulation properties of different barriers in the frequency range above 5 kHz.