Browsing by Author "Medvedieva, Olha O."

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Evaluation of Gabions Usage Effectiveness for Industrial Facilities Protection Against Damage
(Український державний університет науки і технологій, Дніпро, 2025) Medvedieva, Olha O.; Dziuba, Serhii V.; Kalashnikov, Ivan V.; Biliaiev, Mykola M.; Kozachyna, Vitalii A.
ENG: Purpose. In the extreme situations at industrial sites, various damaging factors may appear, such as the spread of toxic substances in the air, the creation of a fireball, etc., which pose a threat to the lives of workers and have a significant negative impact on the environment. That is why today, special attention is being paid to the problems associated with the spread of debris during a drone attack. At an industrial site where oil product storage facilities are located, the debris generated during an explosion can damage the tank building and cause a fire. In this regard, the main objective of the study is to evaluate the effectiveness of using gabion to reduce the risk of damage to the oil storage facility during the movement of drone debris. Methodology. To achieve this goal, the paper considers the problem of flying debris in the event of a drone explosion at an industrial site where oil storage facilities are located. The use of gabion with sand is proposed to protect the tank building from the throwing effect of debris. It is proposed to develop a mathematical model of the movement of a fragment in the path of which the gabion is located. The effect of gabion as a protective screen on reducing the air temperature near a neighboring oil storage facility in the event of a fire at an industrial site is also considered. A model of the dynamics of a point motion (Newton's second law) was used to mathematically describe the movement of the debris. Numerical integration of the modeling equations was performed using the Euler's method. The energy equation was used to model the process of thermal air pollution at an industrial site during a fire. Findings. In this work, the numerical model was programmed and a computer code was created. The programming language is FORTRAN. The code provides information on the speed of the fragment movement in different parts of each zone. On the basis of the constructed numerical model and the created code, parametric studies were carried out to determine the effectiveness of using gabion with sand to protect the oil storage facility from the effects of fragment. As an approximation, the case when the fragment after the explosion moves horizontally in the direction of the object was considered. The influence of the gabion height on the heating level of the wall of the oil storage facility located at an industrial site was analyzed. Originality. An effective mathematical model has been developed to evaluate the effectiveness of using gabion to protect the oil storage facility from damage by drone fragment. The proposed model allows determining the rational dimensions of the gabion to reduce the risk of damage to the tank wall. An effective computer model of thermal air pollution at an industrial site in the event of a fire at an oil storage facility is presented. Practical value. On the basis of the constructed mathematical model, a computer code was created to conduct a computational experiment to determine the effectiveness of using protective barriers (gabions) on the territory of an industrial site.
Experimental Study of Dust Emission Intensity from the Surface of the Alluvium Beach
(IOP Publishing, 2024) Medvedieva, Olha O. ; Biliaiev, Mykola M.; Kozachyna, Vitalii A.; Mormul, Taras; Buketov, Valentyn
ENG: The paper presents data on the current state of waste storage facilities of mining and processing plants in Kryvyi Rih. They are complex, environmentally hazardous hydraulic structures. When assessing the extent of dust pollution from tailing ponds, it is extremely important to know the intensity of dust emissions from the surface of the alluvium beach. This parameter is the basic one in all prognostic models used to predict environmental pollution. The paper presents the results of experimental studies to determine the wind speed at which the removal of dry dust particles from the surface of the beach of a tailing pond begins, as well as the intensity of dust removal from the surface of the beach for dry sand and wet sand. The experimental studies conducted in the laboratory allowed obtaining data on the intensity of dust emission from the surface of the tailing dump beach. The results obtained by the authors make it possible to more accurately assess the degree of environmental dustiness using predictive models. Тhe data on determining the intensity of dust formation for sand of different moisture content will be useful for determining the effectiveness of dust suppression by supplying water to the beach surface.
Forecasting Zones of Air Pollution from Solid Waste Landfills
(Український державний університет науки і технологій, Дніпро, 2025) Medvedieva, Olha O.; Dziuba, Serhii V.; Biliaiev, Mykola M.; Kozachyna, Vitalii A.; Kirichenko, Pavlo S.
ENG: Purpose. The work is aimed at developing a mathematical model that allows to quickly calculate the area of chemical air pollution during the emission of hazardous substances from solid waste landfills. The mathematical model takes into account meteorological parameters, geometric shape of the landfill, intensity of emission of hazardous substances from the landfill. Methodology. The two-dimensional equation of convective diffusion transfer of a conservative impurity from the atmosphere is used to analyze the intensity and size of chemical air pollution during the emission of hazardous substances from the landfill. A difference scheme of splitting is used to numerically solve the equation of convective-diffusive transfer of an impurity. The emission of hazardous substances from the landfill is modeled using the Dirac delta function. Findings. The developed mathematical model takes into account the main physical factors that affect the process of dispersion of hazardous substances from the landfill. On the basis of the developed numerical model, a computational experiment was conducted to assess the impact of the landfill on the environment. Originality. On the basis of the developed numerical model, a computer code was developed that allows predicting chemical pollution of the atmospheric wind and the underlying surface in the event of emission of hazardous substances from the surface of a solid waste landfill. The developed model and computer code make it possible to quickly assess the extent and intensity of environmental pollution from landfills, which is important when selecting sites for new or reconstructed landfills. Practical value. The software implementation of the developed numerical model was carried out, and a computational experiment was conducted to illustrate the effectiveness of using the model to solve applied problems related to the impact of landfills on the environment. The results of the numerical experiment are presented.
Modeling of Filtration and Geomigration Under Anthropogenic Impact on Groundwater
(Ukrainian State University of Science and Technologies, Dnipro, 2025) Medvedieva, Olha O.; Dziuba, Serhii V.; Tiutkin, Oleksii L.; Mashykhina, Polina B.; Berlov, Oleksandr V.
ENG: Purpose. One of the most widespread methods of liquid waste disposal is the use of settling ponds. Wastewater in such lagoons eventually infiltrates into the aeration zone and reaches groundwater. Thus, a chemical contamination area is formed both in the aeration zone and in groundwater. When reengineering sedimentation ponds (for example, when increasing the height of the dam), there is an increase in the pressure in the structure, which will affect the intensity of infiltration of wastewater from the pond into the aeration zone), it is necessary to determine the change in the intensity of environmental pollution in advance. To solve such a forecasting problem, it is necessary to use specialized mathematical models. The aim of the study is to develop numerical models for assessing the dynamics of aeration zone pollution during the infiltration of liquid waste from a sedimentation pond. Methodology. The Laplace equation for the head is used to solve the filtration problem. The process of mass transfer of impurities in the aeration zone is modeled using the mass transfer equation, which takes into account the convective-dispersive transfer of impurities. The numerical integration of the modeling equations is carried out using finite-difference schemes. Findings. Numerical models of filtration and mass transfer are considered, which allow to estimate the dynamics of changes in the contamination area in the aeration zone during the infiltration of liquid wastewater from a sedimentation pond. Originality. The construction of mathematical models for analyzing the infiltration of liquid wastewater from a sedimentation pond is considered. Numerical models take into account the convective-dispersion process of impurity propagation in the aeration area. Practical value. The considered numerical models can be used to assess the environmental impact of sedimentation ponds used for the accumulation of liquid waste.
Numerical Analysis of Aerodynamic Regime Near Tailings Storage Facility
(IOP Publishing Ltd, 2023) Semenenko, Yevhen; Medvedieva, Olha O.; Biliaiev, Mykola M.; Rusakova, Tetiana I.; Blyuss, Konstantin
ENG: Tailings formed during the mining and beneficiation of iron ore are sources of intensive dust generation. In order to assess the intensity of dust formation and determine the effectiveness of methods of its reduction, it is necessary to know the local velocity of the air flow near the various surfaces of the tailings storage facility. For the theoretical solution of this problem, a CFD model was developed, which allows determining the velocity field of the air flow when flowing around the tailings storage facility. The model allows you to obtain the value of the wind speed near the surfaces of the structure and, based on this information, to make a forecast of possible dust formation. The constructed CFD model is based on the use of an aerodynamic model of potential motion. The modeling equation is the Laplace equation for the velocity potential. To build a numerical model, the idea of establishing a solution in time is used, therefore numerical integration of the "unsteady equation" for the velocity potential is carried out. Numerical integration is carried out using the finite-difference method of total approximation. The results of the computational experiment are presented.