Кафедра технології машинобудування (ДМетІ)
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ENG: Department of Technology of Machine Building (IIBT)
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Browsing Кафедра технології машинобудування (ДМетІ) by Author "Anisimov, Volodymyr Mykolajovych"
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Item Cavitation Nozzles with Expansion Chamber(MM Maschinenmarkt, Czech Republic, 2022) Panda, Anton; Anisimov, Volodymyr Mykolajovych; Anisimov, Volodymyr Volodymyrovych; Pandova, Iveta; Klymenko, Anton; Ermakov, PeterENG: An expansion chamber for narrow part of cavitation nozzles is developed. Designs of cavitation nozzles with expansion chamber based on cylindrical nozzle and Venturi nozzle are proposed. The results of calculations of the fluid flow in the presented nozzles show the areas in nozzle, where cavitation is generated, their number, form and power. The plot of volume fraction of vapor phase shows the causes of an increase in the intensity of cavitation in new nozzles with expansion chamber. The main of them is that due to introduction of the expansion chamber, a little area of cavitation generation in the narrow part of cavitation nozzle turns to large one, that causes significant increase in cavitation intensity. The results of comparative experimental studies, which confirm the superiority of cavitation nozzles with the expansion chamber over the basic ones, show that cavitation nozzle with expansion chamber can provide 3 times higher intensity of cavitation, than basic cylindrical nozzle. Also, cavitation nozzle with expansion chamber on the basis of Venturi nozzle can provide 1.5 times higher cavitation intensity, than basic Venturi nozzle.Item Forecasting the Properties of Linear Block-Copoliurethanes Based on Oligoesters of Regular Structure(Ukrainian State University of Chemical Technology, Dnipro, 2021) Anisimov, Volodymyr Mykolajovych; Anisimov, Volodymyr VolodymyrovychENG: We showed that the development of recommendations for a reasonable choice of linear block copolyurethanes that would be optimal for given operating conditions is still intuitive and does not consider the features of the molecular structure and the nature of initial components. We suggested a new scientifically grounded approach to the creation of linear block-copolyurethanes with increased wear resistance in relation to strength, deformation, thermophysical and tribotechnical characteristics. To simplify analysis of the properties of the studied materials, a mathematical model was developed, which describes the relationship between all considered properties of materials and their structure. We proposed to assess the relationship between structure and properties of the investigated materials by using quality indexes. Maximum values of quality indexes, depending on the operating conditions, correspond to different contents of hard blocks (Pc), and, consequently, to different molecular structure of the studied polyurethanes. Thus, it is reasonable to use block-copolyurethanes based on OBGA500 with a maximum content of hard blocks (Ðñ>60%) for operating conditions where it is necessary to provide high strength characteristics. Polyurethanes synthesized with the formation of clusters of hard blocks in the range of 45–55% are recommended for the use as wear-resistant materials.Item Increasing of Wear Resistance of Linear Block-Polyurethanes by Thermal Processing Methods(2021) Panda, Anton; Anisimov, Volodymyr Mykolajovych; Anisimov, Volodymyr Volodymyrovych; Dyadyura, Konstantin; Pandova, IvetaENG: A significant imperfection of parts made from linear block-polyurethanes under conditions of friction contact in the presence of water medium is an intensification of hydrolysis processes and reduction of bulk strength. In order to slow down the hydrolysis process, samples of the polyurethanes were subjected to three types of thermal impacts: thermal processing during some time, infrared and laser irradiations. It has been established that processing in thermal fields of different intensity allows 5-10 times increase of wear resistance of these materials during friction in water medium.Item The Usage of Material Quality Indicators to Assess the Properties of Linear Block-Copolyurethanes Based on Oligoeters(MM Maschinenmarkt, Czech Republic, 2022) Panda, Anton; Anisimov, Volodymyr Mykolajovych; Anisimov, Volodymyr Volodymyrovych; Dyadyura, Konstiantyn; Pandova, IvetaENG: The relationship of the structure with the strength, deformation, thermophysical and tribological characteristics of linear block-copolyurethanes based on oligoeters of regular structure oligooxy tetra-methylene glycol is described by mathematical model. Quality parameters are used to estimate the relationship between the structure and properties of the studied materials. The quality parameters allowed to find optimal composition of initial components.Item Wear Resistance Improvement of Linear Block-Polyurethanes under Conditions of Liquid Friction(De Gruyter Poland, 2021) Panda, Anton; Anisimov, Volodymyr Mykolajovych; Anisimov, Volodymyr Volodymyrovych; Dyadyura, KonstantinENG: A significant disadvantage of parts made of linear block polyurethanes under conditions of friction contact in the presence of an aqueous medium is the intensification of hydrolysis processes and decrease in volume strength. It was proposed to slow down the hydrolysis of polyurethanes in three ways: by directed changes in chemical structure, by electromagnetic radiation of different intensities and by creation of composite materials, based on the principle of additional intermolecular crosslinking at the manufacturing and hot processing stages. The conditions for the formation of a smooth wear-resistant surface that protects the material from rapid destruction are revealed.