Перегляд за Автор "Shevchenko, Serhii"
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Документ Experimental determination of the level of incipient turbulence in the working part of the T-1 wind tunnel of Ivan Kozhedub Kharkiv national Air Force university(Національний технічний університет "Харківський політехнічний інститут", 2021) Bezdielnyi, Vitalii; Shevchenko, Serhii; Hridasov, IlliaThe subject of the article is to determine the level of incipient turbulence in the wind tunnel T-1 which is based on the method of measuring the pressure drop. The purpose is to experimentally determine the level of incipient turbulence in the working part of wind tunnel T-1 of Ivan Kozhedub Kharkiv National Air Force University in preparation for aerodynamic testing of aircraft models. Research methods: the method of pressure drop on the surface of the sphere by drainage. The following results of experimental determination of the level of incipient turbulence in the wind tunnel T-1 were obtained. It is established that the wind tunnel T-1 has a level of incipient turbulence 0,5…0,9 %, which corresponds to the normal condition for further experimental studies. Conclusions. According to the results of studies of the incipient turbulence in the wind tunnel T-1 by the method of pressure drop, the main dependences are obtained, and the incipient turbulence of the flow for the wooden sphere = 0,9 %, and for the metal sphere = 0,5 %, is determined. Determining the pressure distribution and aerodynamic drag does not involve measures to balance the aerodynamic scales and their certification, which determines the necessary role in the obtained reliable results of the experimental study, and this favors the drainage method.Документ Rogowsky coil applications for power measurement under non-sinusoidal field conditions(Lietuvos mokslų akademija, Lithuania, 2019) Diahovchenko, Illia; Mykhailyshyn, Roman; Danylchenko, Dmytro; Shevchenko, SerhiiElectric energy measurement errors depend on the design and algorithms used in electricity meters, as well as on the auxiliary and embedded sensors’ accuracy and bandwidth (or more precisely, maximum measurable frequency). Poor power quality may affect the electric energy meters accuracy, which will lead to the improper power accounting. In this article the applications of the Rogowsky coil sensors for electric energy measurement are studied. The advantages and the challenges of this sensor type implementation are discussed, and the operation scheme of the power meter for the separate measurement of the fundamental harmonic’s electric energy and the higher harmonics electric energy is proposed. The possibility of implementation of responsibility determining methods for power quality distortion is highlighted.