Journal of Engineering Sciences / Журнал інженерних наук
Permanent URI for this collectionhttps://devessuir.sumdu.edu.ua/handle/123456789/34326
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Item Simulation of point defects formation in the fuel element of a nuclear power plant’s wave reactor(Sumy State University, 2023) Opyatyuk, V.V.; Kozlov, I.L.; Karchev, K.D.; Vistiak, S.V.; Kozlov, O.I.; Turmanidze, R.This paper considers the point defects that influence the operation of a wav nuclear power reactor with a uranium fuel medium. The formed individual point defects or such defect groups can produce a perturbing effect on the stability of the nuclear reactor operating mode and involve its transition to an unstable state. Studies have been carried out on the effect on the characteristics of the nuclear burnup wave in a medium with neutron multiplication for 2D geometry. For the calculation, the uranium-thorium fissile medium has been considered. The parametric calculations were carried out with 235 U different enrichment percents and different values of neutron activation energy. At that, it was assumed that the wave (flow) reactor stable operation region is located in the range of activation energies from 10–3 eV to 1 eV or in the region from 2 MeV to 8 MeV. When calculating the neutron flux intensity in a wave reactor, the influence of point defects and their aggregates on the decelerating elastically scattered neutrons’ flux density and the flux density of decelerating non-elastically scattered neutrons was considered. The dependences of the point defects formation rate on the medium fissile temperature for several compositions of the uranium-thorium medium are obtained. As visually identified, the graphic materials obtained during the calculations are similar to the photos of fuel rods after the energy campaign.Item Design in modern information systems by applying cloud technologies(Sumy State University, 2023) Tigariev, V.; Lopakov, O.; Rybak, O.; Kosmachevskiy, V.; Cioată, V.G.In this study, the general algorithm and technology of design in advanced computer-aided design (CAD) software of the CAD-in-the-Cloud type using an information model (IM) was discussed in detail. Applying design systems of this type increases productivity and quality of the development and enables group work on the project. The proposed information model consists of three main components – working with Autodesk Fusion 360 on a computer, working with cloud capabilities, and designers’ collaboration through the cloud. Nevertheless, some IM elements may be missing in a particular design, or there can be options for applying the proposed steps in the design process. Developing customized respiratory protective equipment (face masks) in Autodesk Fusion 360 CAD family was considered as an example of the suggested IM application. Modern design and producing technologies enable the creation of masks according to individual anatomical characteristics of the human face. In this paper, the protective mask was created by applying modern cloud computing technologies using information models. Information models were adapted to the process of protective mask design. The model of a human headform was developed using the 3D scanning method. After applying retopology tools, a basis of the mask frame was created on the surface of a 3D model of a head. Building a solid model and testing the mask fame configuration under mechanical stresses due to facial expression changing was carried out in Autodesk Fusion 360 CAD software. Finally, the cloud module of the generative design was applied to determine the filtering element configuration.Item Modeling a viscoelastic support considering its mass-inertial characteristics during nonstationary vibrations of the beam(Sumy State University, 2023) Voropay, A.V.; Menshykov, O.V.; Povaliaiev, S.I.; Sharapata, A.S.; Yehorov, P.A.Non-stationary loading of a mechanical system consisting of a hinged beam and additional support installed in the beam span was studied using a model of the beam deformation based on the Timoshenko hypothesis with considering rotatory inertia and shear. The system of partial differential equations describing the beam deformation was solved by expanding the unknown functions in the Fourier series with subsequent application of the integral Laplace transform. The additional support was assumed to be realistic rather than rigid. Thus it has linearly elastic, viscous, and inertial components. This means that the effect of a part of the support vibrating with the beam was considered such that their displacements coincide. The beam and additional support reaction were replaced by an unknown concentrated external force applied to the beam. This unknown reaction was assumed to be time-dependent. The time law was determined by solving the first kind of Volterra integral equation. The methodology of deriving the integral equation for the unknown reaction was explained. Analytic formulae and results of computations for specific numerical parameters were given. The impact of the mass value on the additional viscoelastic support reaction and the beam deflection at arbitrary points were determined. The research results of this paper can be helpful for engineers in designing multi-span bridges.Item Information-extreme machine learning of wrist prosthesis control system based on the sparse training matrix(Sumy State University, 2022) Супруненко, Микита Костянтинович; Супруненко, Никита Константинович; Suprunenko, Mykyta Kostiantynovych; Зборщик, Олександр Петрович; Зборщик, Александр Петрович; Zborshchyk, Oleksandr Petrovych; Sokolov, O.The article considers the problem of machine learning of a wrist prosthesis control system with a noninvasive biosignal reading system. The task is solved within the framework of information-extreme intelligent data analysis technology, which is based on maximizing the system’s information productivity in machine learning. The idea of information-extreme machine learning of the control system for recognition of electromyographic biosignals, as in artificial neural networks, consists in adapting the input information description to the maximum total probability of making correct classification decisions. However, unlike neuro-like structures, the proposed method was developed within a functional approach to modeling the cognitive processes of the natural intelligence of forming and making classification decisions. As a result, the proposed method acquires the properties of adaptability to the intersection of classes in the space of recognition features and flexibility when retraining the system due to the recognition class alphabet expansion. In addition, the decision rules constructed within the framework of the geometric approach are practically invariant to the multidimensionality of the space of recognition features. The difference between the developed method and the well-known methods of information-extreme machine learning is the use of a sparse training matrix, which allows for reducing the degree of intersection of recognition classes significantly. The optimization parameter of the input information description, the training dataset, is the quantization level of electromyographic biosignals. As an optimization criterion is considered the modified Kullback information measure. The proposed machine learning algorithm results are shown in the example of recognition of six finger movements and wrist.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.Item Simulation of reverse osmosis process: Novel approaches and development trends(Sumy State University, 2022) Huliienko, S.V.; Korniyenko, Y.M.; Muzyka, S.M.; Holubka, K.Reverse osmosis is an essential technological separation process that has a large number of practical applications. The mathematical simulation is significant for designing and determining the most effective modes of membrane equipment operation and for a deep understanding of the processes in membrane units. This paper is an attempt at systematization and generalizing the results of the investigations dedicated to reverse osmosis simulation, which was published from 2011 to 2020. The main approaches to simulation were analyzed, and the scope of use of each of them was delineated. It was defined that computational fluid dynamics was the most used technique for reverse osmosis simulation; the intensive increase in using of molecular dynamics methods was pointed out. Since these two approaches provide the deepest insight into processes, it is likely that they will further be widely used for reverse osmosis simulations. At the same time, for the simulation of the membrane plant, it is reasonable to use the models that required the simplest solutions methods. The solution-diffusion model appears to be the most effective and flexible for these purposes. Therefore, this model was widely used in considering the period. The practical problems solved using each of the considered approaches were reviewed. Moreover, the software used for the solution of the mathematical models was regarded.Item Ways for improvement of reverse axial pumps(Sumy State University, 2022) Мандрика, Анатолій Семенович; Мандрыка, Анатолий Семенович; Mandryka, Anatolii Semenovych; Majid, A.P.; Ратушний, Олександр Валерійович; Ратушный, Александр Валерьевич; Ratushnyi, Oleksandr Valeriiovych; Куліков, Олександр Андрійович; Куликов, Александр Андреевич; Kulikov, Oleksandr Andriiovych; Сухоставець, Дар'я Ігорівна; Сухоставец, Дарья Игоревна; Sukhostavets, Daria IhorivnaThe article is devoted to a pilot study of the reverse-bladed pump. The characteristics of the reverse bladed pump are the identical parameters on flow, the head, power, energy efficiency on direct and the return operating modes (at rotation of a rotor of the pump both in one and to the opposite side). The model reversible axial pump with two impeller versions was tested on an experimental bench. The impellers were distinguished by the shape of the profile in the blade sections. The model reversible pump was structurally a reversible axial impeller placed in a cylindrical chamber. Studies were carried out at different angles of rotation of the impeller blades. The power characteristics of tested versions of the pump (impeller) at the design and under loading (unstable operation) modes are given. Low efficiency of the tested versions of the reversible pump compared to the conventional axial pumps is noted, primarily due to the strong influence of the secondary gradients of the pressure factor. The second reason is the profile separation of the flow from the blade surface, to which the tested reverse pump screens are predisposed.