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Документ Numerical study of flow parameters in the high-head francis turbine(Національний технічний університет "Харківський політехнічний інститут", 2024) Krupa, Yevhenii; Demchuk, RomanThe scientific exploration of numerical computation regarding spatial flow within hydraulic machinery components is examined. A survey of contemporary software systems is conducted, and the benefits of their utilization over experimental studies are evaluated. It is indicated that the optimal approach involves a blend of experimental investigations and numerical simulation. This methodology facilitates the validation of simulation outcomes under real-world conditions and iteratively enhances the model based on acquired data. A review of the widely utilized Ansys software program is provided, emphasizing its pivotal features and capabilities for analyzing flow components of hydraulic turbines. An algorithm for computing flow parameters in hydraulic turbines using the Ansys software suite is outlined. The subject of this study is the high-head Francis hydraulic turbine Fr 500. The turbine's geometry was constructed employing a sector-based approach. This technique allows for significant simplification of calculations within the computational fluid dynamics framework, thereby reducing computational workload while preserving result accuracy. In selecting mathematical and turbulence models, a comprehensive analysis of the problem was undertaken, identifying models most suitable for the specific situation to ensure dependable numerical simulation outcomes. For spatial flow calculations in the turbine's flow component, the standard k-ε turbulence model was adopted. Considerable attention was devoted to mesh generation, as mesh quality strongly influences result accuracy and reliability. An unstructured mesh comprising tetrahedral-shaped cells was employed for discretizing the flow component, with local mesh refinement at the edges of the runner blades and guide vanes. As a result of numerical computations, the values of primary flow parameters for the design operating mode were determined. A visualization of the flow within the flow component is provided, alongside the assessment of hydraulic losses and turbine efficiency. The efficiency values obtained differ from corresponding experimental values by no more than 1 %. A thorough examination of the flow structure within the flow path was conducted, yielding recommendations for adjusting the blade angle β1 to reduce inlet impact losses.Документ Improvement of an engineering procedure for calculating the nonisothermal transportation of a gasliquid mixture(Технологический центр, 2019) Fyk, M. I.; Biletskyi, V. S.; Fyk, I.; Bondarenko, Volodymyr; Mohammed, Bassam Al-SultanThe study that we conducted into the process of transportation of a gas-condensate mixture from a well bottom to the separation production plant has revealed the features of isothermal and non-isothermal flow. It was proved that during non-isothermal flow, hydraulic losses in the product pipeline are significantly affected by throttle effect and energy accommodation effect. The influence of velocity and volumetric flow rate of the gas-liquid mixtures on hydraulic resistance and pressure drop on a section of product pipeline, taking into consideration non-isothermal flow was analyzed. It was found that the assessment of hydraulic resistance and pressure drop in the proposed dependences converges with standardized ones by 95 %. The result was obtained based on the developed system of equations of the mathematical model for non-isothermal non-stationary one-dimensional motion of the gas-liquid mixture of hydrocarbons in the pipeline. The proposed system beneficially differs from the known ones by the fact that it takes into consideration the inner convective heat exchange, estimated by the combined effect of Joule-Thomson. A distinctive feature of the improved procedure for calculation was the introduction of temperature correction and accommodation coefficient in the calculation of hydraulic resistance of a pipeline as a system with distributed parameters. Due to this, it became possible to improve the procedure for the calculation of non-isothermal transportation of a homogeneous gas-condensate mixture. Based on the analysis of calculation curves by the known procedures (formulas of Thomas Colebrooke, Leibenson and VNIIgas) for isothermal and non-isothermal processes and the proposed procedure, rational areas of their applications were shown. All calculations were performed at the velocity of a gas-liquid flow within the range 0–50 m/s, pipe roughness of 0.01–0.05 mm and their diameter of 100–300 mm, the data from actual production pipelines of Novotroitsk oil-gas condensate field were used. Comparison of the theoretical and industrial experiments showed sufficient for engineering practice accuracy of calculation of pressure drop on the stretches of oil and gas lead lines and allowed recommending the developed analytical dependences for the introduction in industrial engineering.Документ Теоретичний аналіз основних тягових показників вантажного автомобіля з двопотоковою гідрооб’ємно-механічною трансмісією(НТУ "ХПІ", 2018) Самородов, Вадим Борисович; Гармаш, Дмитро ОлександровичПідвищення технічних показників завжди мало пріоритетний характер на всіх етапах розвитку автомобіле- і тракторобудування. В представленній статті піде мова про теоретичне обгрунтування використання гідрооб’ємно-механічної трансмісії. В якості об’єкта дослідження були використані двопотокова ГОМТ №1, розроблена кафедрою «Автомобіле- і тракторобудування» НТУ «ХПІ», та автомобіль КрАЗ 6233МДокумент To the question of increasing the pilot performance of the stage of the submersible centrifugal pump at the production of oil and gas production(NTU "KhPI", 2017) Shudryk, A. L.; Koval, E. S.; Doroshenko, Aleksandr VladislavovichA review of existing designs of stages of submersible centrifugal pumps, research and ways to increase of head. The main causes of energy losses in the flow parts of pumps of the ESP type are described. A numerical model for simulating multiphase flows has been determined. Numerical simulation of the flow of GLM is carried out. The ways of increasing the assertiveness are determined. The values of the head in the moving and stationary elements of the flow part are obtained. headlosses in submersible centrifugal pumps are analyzed. A modified flow part is proposed, which allows to reduce hydraulic losses and increase the power of the entire stage as a whole. The calculation of the modified step is carried out. The flow of the gas-liquid mixture in the modified stage is visualized. The pressure and energy characteristics of the new stage are obtained. The distribution of static pressure along the blade is shown for different gas contents.Документ Гидравлический расчет камеры отбора паровой турбины(НТУ "ХПИ", 2016) Лапузин, Александр Викторович; Субботович, Валерий ПетровичРассмотрено влияние диаметра и количества отводящих патрубков на уровень гидравлических потерь при входе в эти патрубки. Усовершенствована методика расчета натурных трактов теплофикационных отборов при отводе пара из турбины как через один, так и через два патрубка. Обобщены результаты проведенных в НТУ "ХПИ" исследований камер отбора на крупномасштабном статическом стенде.