Journal of Engineering Sciences / Журнал інженерних наук
Permanent URI for this collectionhttps://devessuir.sumdu.edu.ua/handle/123456789/34326
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Item Effect of erosion on surface roughness and hydromechanical characteristics of abrasive-jet machining(Sumy State University, 2024) Baha, V.; Pitel, J.; Павленко, Іван Володимирович; Pavlenko, Ivan VolodymyrovychThe article contains the fundamental results of the experimental and numerical investigations for pneumoabrasive unit nozzles with different geometries. The research was purposed by the pressing need to develop an inexpensive and effective working nozzle design of the air-abrasive unit which can be applied for surface processing before some technological processes are performed, as well as for surface coating, descaling after thermal treatment, processing of hollow holes of the crankshafts, smoothing of the inner surfaces of the narrow channels between the impeller blades after electric discharge machining for ultrahigh-pressure combination compressors. Several designs were considered, ranging from the simplest to those with a complicated inner channel geometry. The impact of the nozzle material and challenging inner surface application on its characteristics has also been studied. The research was done using the application of modern CFD complexes for numerical modeling of the air-abrasive mixture discharge from the working nozzle of the pneumo-abrasive unit. In addition, physical experimentation was provided. The methods applied in the research allow for profound, systematic research of spraying units operating on the air-abrasive mixture within a wide range of geometrical and mode parameters. The novelty of the gained results lies in the development of the mathematical model of the pneumo-abrasive nozzle operating process, the working out of a cheaper nozzle design, getting information about air-abrasive mixture distribution along the nozzle length, giving practical recommendations for calculation and designing a working nozzle for the jet-abrasive unit.Item Design and manufacturing of polymer composite materials using quality management methods(Sumy State University, 2023) Берладір, Христина Володимирівна; Берладир, Кристина Владимировна; Berladir, Khrystyna Volodymyrivna; Mitalova, Z.; Павленко, Іван Володимирович; Павленко, Иван Владимирович; Pavlenko, Ivan Volodymyrovych; Trojanowska, J.; Іванов, Віталій Олександрович; Иванов, Виталий Александрович; Ivanov, Vitalii Oleksandrovych; Руденко, Павло Володимирович; Руденко, Павел Владимирович; Rudenko, Pavlo VolodymyrovychMany factors influence the design and manufacturing of products from polymer composite materials. The expert assessment method was applied in the article for the corresponding analysis. A cause-and-effect diagram was built as a result of a preliminary analysis of the influence of factors on the primary indicator of product quality indicators (e.g., wear resistance). Based on the expert assessment results and quality function deployment analysis, the most critical factors affecting wear resistance were obtained: polymer brand, filler shape and size, technological parameters of mixing, pressing, sintering, and mechanical processing. Their impact was studied to establish quantitative dependencies. A stable value of the wear resistance of the product in the manufacturing process can be ensured by timely adjustment of the mixing, pressing, and sintering modes. As a result of the structural analysis of the process of developing materials with predetermined properties at the enterprise according to the IDEF0 methodology, the importance of assessing the risks associated with the process of multi-criteria optimization of their main quality indicators was confirmed.Item Rotor dynamics of turbocompressor based on the finite element analysis and parameter identification approach(Sumy State University, 2022) Вербовий, Антон Євгенович; Вербовой, Антон Евгеньевич; Verbovyi, Anton Yevhenovych; Хоменко, Владислав Володимирович; Хоменко, Владислав Владимирович; Khomenko, Vladyslav Volodymyrovych; Neamtu, C.; Pavlenko, V.; Симоновський, Віталій Іович; Симоновский, Виталий Иович; Symonovskyi, Vitalii Iovych; Павленко, Іван Володимирович; Павленко, Иван Владимирович; Pavlenko, Ivan VolodymyrovychThe article is devoted to improving methods for designing a finite element model of rotor dynamics. For this purpose, numerical implementation of the authors’ computer program “Critical frequencies of the rotor” was developed based on the computer algebra system MathCAD. As a result of the scientific work, a refined mathematical model of rotor dynamics using finite beam elements was created. This model considers the dependence of the radial stiffness characteristics of the bearing supports on the values of the critical frequencies. The reliability of the mathematical model was justified by the permissible differences of the obtained results within 2% compared with the results of finite element analysis using the ANSYS software. The theorem was also proven by the mutual location of the spectra of the natural and critical frequencies. Overall, the proposed scientific approach reduces preparation and machine time compared to numerical modeling using the ANSYS software without losing the accuracy of the calculations.