Факультет технічних систем і енергоефективних технологій (ТеСЕТ)
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Item Computer Simulation of Composite Materials Behavior under Pressing(MDPI, 2022) Берладір, Христина Володимирівна; Berladir, Khrystyna Volodymyrivna; Жигилій, Дмитро Олексійович; Zhyhylii, Dmytro Oleksiiovych; Brejcha, J.; Позовний, Олександр Олександрович; Pozovnyi, Oleksandr Oleksandrovych; Krmela, J.; Krmelová, V.; Артюхов, Артем Євгенович; Artiukhov, Artem YevhenovychComposite materials have a wide range of functional properties, which is ensured by using various technological methods of obtaining both the matrix or fillers and the composition as a whole. A special place belongs to the composition formation technology, which ensures the necessary structure and properties of the composite. In this work, a computer simulation was carried out to identify the main dependencies of the behavior of composite materials in the process of the main technological operations of their production: pressing and subsequent sintering. A polymer matrix randomly reinforced with two types of fillers: spherical and short cylindrical inclusions, was used to construct the finite element models of the structure of composites. The ANSYS Workbench package was used as a calculation simulation platform. The true stress–strain curves for tension, Poisson’s ratios, and ultimate stresses for composite materials were obtained using the finite element method based on the micromechanical approach at the first stage. These values were calculated based on the stretching diagrams of the matrix and fillers and the condition of the ideality of their joint operation. At the second stage, the processes of mechanical pressing of composite materials were modelled based on their elastic–plastic characteristics from the first stage. The result is an assessment of the accumulation of residual strains at the stage before sintering. The degree of increase in total strain capability of composite materials after sintering was shown.Item Parameter Identification of the Fractional-Order Mathematical Model for Convective Mass Transfer in a Porous Medium(MDPI Publishing, 2023) Павленко, Іван Володимирович; Pavlenko, Ivan Volodymyrovych; Ochowiak, M.; Włodarczak, S.; Krupinska, A.; Matuszak, M.Fractional calculus is an essential tool in studying new phenomena in hydromechanics and heat and mass transfer, particularly anomalous hydromechanical advection–dispersion considering the fractal nature of the porous medium. They are valuable in solving the urgent problem of convective mass transfer in a porous medium (e.g., membranes, filters, nozzles, convective coolers, vibrational prillers, and so on). Its solution allows for improving chemical engineering and technology workflows, refining process models for obtaining porous granular materials, realizing the convective cooling of granular and grain materials, and ensuring the corresponding apparatuses’ environmental safety. The article aims to develop a reliable convective mass transfer model for a porous medium and proposes a practical approach for its parameter identification. As a result, a general scientific and methodological approach to parameter identification of the fractional convective mass transfer model in a porous medium was proposed based on available experimental data. It mainly used Riemann–Liouville fractional time and coordinate derivatives. The comprehensive application of the Laplace obtained the corresponding general solution transform with respect to time and a coordinate, the Mittag-Leffler function, and specialized functions. Different partial solutions in various application case studies proved this solution. Moreover, the algorithm for practically implementing the developed approach was proposed to evaluate parameters for the considered model by evaluation data. It was reduced to the two-parameter model and justified by the available experimental data.Item An Increase in the Energy Efficiency of R744 Heat-Using Thermotransformers(MDPI, 2023) Арсеньєв, В`ячеслав Михайлович; Arseniev, Viacheslav Mykhailovych; Piteľ, J.; Король, Олександр Сергійович; Korol, Oleksandr Serhiiovych; Шарапов, Сергій Олегович; Sharapov, Serhii Olehovych; Mižáková, J.; Павленко, Іван Володимирович; Pavlenko, Ivan Volodymyrovych; Іванов, Віталій Олександрович; Ivanov, Vitalii OleksandrovychThis article deals with improving waste heat transformation in heat-using thermotransformers. Based on the directives of the European Commission on refrigeration equipment requirements, the possibility of using carbon dioxide (R744) in heat-using thermotransformers was evaluated. The possibility of the effective use of heat-using thermotransformers operating within the Chistyakov–Plotnikov cycle in the heat pump mode was assessed. As a result, a comparative analysis was performed with existing modern plants for combined cycles with an expander, for the expansion of CO2 in saturated steam, a suction gas heat exchanger (SGHE), and a compressor–expander unit. The design schemes with a throttling device and an SGHE were selected for a comparative analysis. As a result, calculation models for evaluating the operating parameters for the initial and proposed design schemes were developed. These models allow for evaluating thermodynamic and mode parameters for heat-reducing thermotransformers. They also allow for ensuring energy efficiency indicators and conversion factors for each cycle. Overall, the dependencies for the cycle conversion ratio for the pressure increase stage in the compressor were obtained for various under-recovery rates. Moreover, the cycle conversion ratios for the proposed design schemes were obtained depending on the discharge pressure of the first compressor. The proposed design schemes allow for increasing the energy efficiency of heat-using thermotransformers by an average of 23%, depending on the suction pressure in the compressor.Item Experimental Studies and Condition Monitoring of Auxiliary Processes in the Production of Al2O3 by Sol–Gel Technology(MDPI, 2022) Склабінський, Всеволод Іванович; Склабинский, Всеволод Иванович; Sklabinskyi, Vsevolod Ivanovych; Ляпощенко, Олександр Олександрович; Ляпощенко, Александр Александрович; Liaposhchenko, Oleksandr Oleksandrovych; Piteľ, J.; Павленко, Іван Володимирович; Павленко, Иван Владимирович; Pavlenko, Ivan Volodymyrovych; Скиданенко, Максим Сергійович; Скиданенко, Максим Сергеевич; Skydanenko, Maksym Serhiiovych; Острога, Руслан Олексійович; Острога, Руслан Алексеевич; Ostroha, Ruslan Oleksiiovych; Юхименко, Микола Петрович; Юхименко, Николай Петрович; Yukhymenko, Mykola Petrovych; Simeiko, K.; Demianenko, M.; Volf, M.; Starynskyi, O.; Юрченко, Олександр Юрійович; Юрченко, Александр Юрьевич; Yurchenko, Oleksandr Yuriiovych; Мандрика, О.Powders and granules of heavy metal oxides produced through condition monitoring are in high demand as intermediate products for obtaining fine-grained ceramics for a wide range of applications, i.e., nuclear fuel and fuel elements for nuclear power plants. Sol–gel technology to produce nuclear fuel (UO2), as well as catalysts (ThO2) for organic synthesis in the form of granules from pressed microspheres, is a promising method to obtain powders and granules of heavy metal oxides (fine-graded ceramics). Al2O3 was selected as the model analog at the stages of obtaining a solution of heavy metal and sol, the formation and gelation of droplets, and the preparation of gel spheres and their further washing and drying, as well as recovery and firing of particles. In the study, the main parameters were substantiated, e.g., the diameter and angle of inclination of the axis for the holes in the perforated shell, the multiplicity of sol circulation before the holes, the coefficients of liquid (sol) flow rate, the oscillation frequency of the disperser, and the concentration of surfactant and acid in sol. All of these parameters affect the characteristics of the granules that are obtained by sol–gel technology. Moreover, recommendations to increase productivity and the energy efficiency of production were also given. In particular, it was found that oscillation frequency in a range of 70–80 Hz leads to a granulometric composition of the obtained granules of 2.0–2.2 mm. A hole of 0.85 mm and a frequency of 100 Hz slightly change this range to 1.2–2.0 mm, while maintaining monodispersity.Item Development of Flexible Fixtures with Incomplete Locating: Connecting Rods Machining Case Study(MDPI, 2022) Іванов, Віталій Олександрович; Иванов, Виталий Александрович; Ivanov, Vitalii Oleksandrovych; Botko, F.; Dehtiarov, I.; Kočiško, M.; Evtuhov, A.; Павленко, Іван Володимирович; Павленко, Иван Владимирович; Pavlenko, Ivan Volodymyrovych; Trojanowska, J.The rapid development of manufacturing in recent years has led to a significant expansion of the technological capabilities of modern metal-cutting equipment. Therefore, the modern approach to intensifying production requires an advanced fixture design. Design and manufacture of flexible fixtures capable of machining similar shapes and sizes of complex geometry parts reduce setup time. The article aims to design flexible fixtures for parts such as one-piece connecting rods under incomplete locating conditions. The advantages are the minimum number of parts and tool availability for multi-axis machining connecting rods in one setup. This approach, combined with up-to-date machining centers and industrial robots, can increase the production efficiency of manufacturing non-removable connecting rods. This effectiveness is in a decrease in the number of operations by 5–7 times, fixtures—by 3–4 times, and machine tools—by 3–5 times, depending on the type of a non-removable connecting rod and its design features. The numerical simulation results of the proposed fixture design confirmed the comprehensive technological capabilities and dynamic characteristics. Particularly, a decrease in displacements and oscillation amplitudes up to 7% compared to the full-basing locating chart was provided. It is determined that the system “fixture–workpiece” entirely meets all the strength, accuracy, and rigidity parameters, which allows you to perform machining with intensive cutting modes. The amplitudes of oscillations do not exceed the tolerances on the dimensions of these surfaces, established by requirements for non-removable connecting rods, and all displacements are elastic. During numerical simulation, the workpiece position remained stable at all machining steps.Item Using Regression Analysis for Automated Material Selection in Smart Manufacturing(MDPI, 2022) Павленко, Іван Володимирович; Павленко, Иван Владимирович; Pavlenko, Ivan Volodymyrovych; Pitel, J.; Іванов, Віталій Олександрович; Иванов, Виталий Александрович; Ivanov, Vitalii Oleksandrovych; Берладір, Христина Володимирівна; Берладир, Кристина Владимировна; Berladir, Khrystyna Volodymyrivna; Mizakova, J.; Колос, Віталій Олександрович; Колос, Виталий Александрович; Kolos, Vitalii Oleksandrovych; Trojanowska, J.In intelligent manufacturing, the phase content and physical and mechanical properties of construction materials can vary due to different suppliers of blanks manufacturers. Therefore, evaluating the composition and properties for implementing a decision-making approach in material selection using up-to-date software is a topical problem in smart manufacturing. Therefore, the article aims to develop a comprehensive automated material selection approach. The proposed method is based on the comprehensive use of normalization and probability approaches and the linear regression procedure formulated in a matrix form. As a result of the study, analytical dependencies for automated material selection were developed. Based on the hypotheses about the impact of the phase composition on physical and mechanical properties, the proposed approach was proven qualitatively and quantitively for carbon steels from AISI 1010 to AISI 1060. The achieved results allowed evaluating the phase composition and physical properties for an arbitrary material from a particular group by its mechanical properties. Overall, an automated material selection approach based on decision-making criteria is helpful for mechanical engineering, smart manufacturing, and industrial engineering purposes.Item Flow Modeling in a Vortex Chamber of a Liquid–Steam Jet Apparatus(MDPI, 2022) Мерзляков, Юрій Сергійович; Мерзляков, Юрий Сергеевич; Merzliakov, Yurii Serhiiovych; Павленко, Іван Володимирович; Павленко, Иван Владимирович; Pavlenko, Ivan Volodymyrovych; Ochowiak, M.; Іванов, Віталій Олександрович; Иванов, Виталий Александрович; Ivanov, Vitalii Oleksandrovych; Agarwal, P.The article investigated the flow of boiling streams through a nozzle with an oblique cut. Due to this flow organization, deviation from the nozzle axis at the vortex chamber inlet occurred. The study of flow modeling in the inlet section was carried out. The flow design and the calculation scheme of the vortex liquid–steam jet apparatus were proposed. Analytical expressions between the main operating parameters were obtained according to the developed mathematical model. A recommended oblique-cut angle for the active-flow nozzle was evaluated considering the transition through the first critical section based on the tangential velocity flow model. Validation of the mathematical model in the inlet section of the vortex chamber was provided based on the comparison with available experimental data. Flow visualization in the inlet section of the vortex chamber was obtained. The assumption of uneven flow distribution was confirmed experimentally. Overall, the boiling liquid flow was implemented in the active flow nozzle. The obtained scientific and practical results help to determine geometric parameters and physical characteristics of the vortex-type liquid–steam jet apparatus at the design stage. The obtained results were implemented to modernize vacuum units based on vortex type liquid–steam jet apparatuses.Item Composition, Structure, and Properties of Ti, Al, Cr, N, C Multilayer Coatings on AISI W1-7 Alloyed Tool Steel(MDPI, 2022) Loskutova, T.; Hatala, M.; Pogrebova, I.; Nikitina, N.; Bobina, M.; Radchenko, S.; Харченко, Надія Анатоліївна; Харченко, Надежда Анатольевна; Kharchenko, Nadiia Anatoliivna; Kotlyar, S.; Павленко, Іван Володимирович; Павленко, Иван Владимирович; Pavlenko, Ivan Volodymyrovych; Іванов, Віталій Олександрович; Иванов, Виталий Александрович; Ivanov, Vitalii OleksandrovychNew methods of diffusion metallization of AISI W1-7 steel have been developed. The paper proposes a comparative analysis of the properties and characteristics of AISI W1-7 steel after three methods of chemical heat treatment: diffusion nitriding, nitrogen titration by physical deposition from the gas phase, and diffusion chromium plating with subsequent titanium alloys. The results are presented as a comprehensive analysis of coatings: metallographic, micro-X-ray spectral, X-ray phase, durometric, heat resistance, and wear resistance. It is established that multilayer protective coatings are formed as a result of treatments. It is shown that the coatings consist of carbide and nitride zones, intermetallic, and an Al2O3 layer outside the coating. The coatings have been found to contain barrier layers that prevent aluminum from penetrating the substrate. The maximum microhardness is typical for layers based on titanium carbide—30.3–35.5 GPa and titanium nitride—22.0–22.6 GPa, heat-resistant steels AISI W1-7 at a temperature of 900 °C in 4.2–8.5 times and wear resistance under sliding friction without lubrication up to 5.4 times compared to samples without treatment.