Browsing by Author "Kozachyna, Vitalii A."
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Item Analysis of Temperature Field in the Transport Compartment of the Launch Vehicle(Kaunas University of Technology, Kaunas, 2022) Biliaiev, Mykola M.; Rusakova, Tetiana I.; Biliaieva, Viktoriia V.; Kozachyna, Vitalii A.; Berlov, Oleksandr V.; Semenenko, PavloENG: The development of satellite linkage systems is based on the satellite’s transportation in space. The transportation of a satellite into orbit is carried out by a launch vehicle. The satellite is located in the transport compartment inside the main fairing. At the stage of the pre-launch preparation, it is necessary to fulfill very strict environment conditions inside the main fairing. Namely, it is very important to predict temperature field in the transport compartment inside the main fairing during its forced ventilation at the stage of pre-launch preparation. To calculate the temperature field formed by the ventilation of the transport compartment and release of heat from different elements of the satellite, the energy equation was used. This equation took into account the intensity of heat release from different parts of satellite, air flow pattern over the satellite, heat transfer in the transport compartment. The non-uniform field of the air flow velocity in the transport compartment was calculated on the basis of the potential flow model. The finite difference schemes were used for numerical integration of modeling equations. The computer code has been developed that implements the proposed numerical model. The results of computational experiments to estimate the temperature regime in the main fairing of the launch vehicle for different satellites is presented.Item Anti-Terror Engineering in the Case of Possible Terrorist Attacks with Chemical Agents(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпро, 2018) Biliaev, Nikolai N.; Berlov, Oleksandr V.; Kalashnikov, Ivan V.; Kozachyna, Vitalii A.ENG: Purpose. This work aims to develop a method of local outdoor reduction of the concentration of a chemically hazardous substance, which entered the atmosphere through a cafe roof vent. It also involves the creation of a numerical model for calculating the chemical contamination zone that allows assessing the effectiveness of the screens used to minimize its level. Methodology. To solve this problem, we used the velocity potential equation that al-lowed to determine the air flow velocity field, and the equation of convective diffusion dispersion of a chemically hazardous agent in the atmospheric air emitted through the ventilation system in case of a terrorist attack. The simulation took into account the uneven velocity field of the wind flow, atmospheric diffusion, emission rate of a chemically hazardous agent. In the numerical integration of the velocity potential equation, we used the Liebmann method. For the numerical solution of the equation of convective diffusion dispersion of the impurity, an implicit alternate-triangular difference splitting scheme was used. Findings. The developed numerical model allowed assessing the effectiveness of building screens used to reduce the concentration of a hazardous substance and minimize the risk of toxic damage to people outdoor during an initiated emission of a chemical agent. The constructed numerical model can be implemented on computers of low and medium power, which allows it to be widely used for solving problems of the class under consideration when developing an anti-terror engineering strategy. Originality. An effective numerical model for calculating the outdoor chemical contamination zone during a possible terrorist attack using a chemical (biological) agent has been proposed. The model can also be applied to assess the effectiveness of some protective measures aimed at reducing the air pollution level during a terrorist attack. Practical value. The developed numerical model can be used to organize protective actions near social objects of a possible chemical attack by a terrorist.Item Atmosphere Pollution Modeling in the Case of Accident During Rocket Propellant Transportation by Trains(Dnipro National University of Railway Transport named after Academician V. Lazaryan, 2019) Biliaiev, Mykola M.; Biliaieva, Viktoriia V.; Kozachyna, Vitalii A.; Berlov, Oleksandr V.; Gunko, Olena Yu.; Chernyatyeva, KaterynaEN: Abstract. At present time, in Ukraine the intensive development of solid-propellant missiles takes place. These missiles are called «Grim», «Grim-2», etc. Transportation of rocket propellant very often is carried out by trains. In the case of accident during such transportation great amount of toxic chemicals may be emitted into atmosphere. It is very important to predict the atmosphere pollution level near railways transport corridors to obtain the realistic information about the size of possible zones of hitting. To forecast the atmosphere pollution in the case of rocket propellant burning in railway wagon numerical models have been developed. These models are developed to predict the atmosphere pollution in two scales. The first scale is the simulation of the atmosphere pollution near the railway tracks (so called “local scale”). The second scale is the simulation of the atmosphere pollution on the territory which is adjacent to the railway tracks («urban scale»). The forecast is based on the Lagrangian model of toxic chemical dispersion. The models allow also to predict acid rain formation in the case of solid propellant burning products dispersion into atmosphere. To solve the governing equations we used difference schemes of splitting. The results of numerical experiments are presented.Item Calculation of the Efficiency of the Horisontal Settler with Baffles(Саратов, 2014) Biliaiev, Nikolay N.; Kozachyna, Vitalii A.; Polubinskaja, E. V.EN: The main purpose of this paper is development of the effective CFD model which can be used for computation speed field of the flow in the horizontal settlers which takes into account the geometrical form of the settler.Item Calculation of «Vulnerability» Zone in Case of Terrorist Attack with Chemical Agents(Дніпропетровський національний університет залізничного транспорту ім. акад. В. Лазаряна, Дніпро, 2018) Biliaiev, Mykola M.; Berlov, Oleksandr V.; Kalashnikov, Ivan V.; Kozachyna, Vitalii A.EN: Purpose. The work involves the development of a numerical model for calculating the «vulnerability» zone of a possible terrorist attack objective with the use of a chemical agent in a builtup environment. The «vulnerability» zone is a territory near the attack objective, where the emission of a chemical agent during the attack will lead to undesirable consequences. The emission of a chemical agent outside the «vulnerability» zone will not create a dangerous concentration near the attack objective. Methodology. To solve this problem, we use the equation for the velocity potential, on the basis of which we determine the wind stream velocity field, and the equation adjoint to the equation of mass transfer in the atmospheric air of the chemical agent emitted in the event of a terrorist attack. During simulation, we take into account the uneven wind stream velocity field, atmospheric diffusion and the rate of emission of a chemically hazardous substance. For the numerical integration of the velocity potential equation, we use the method of A. A. Samarsky. For numerical solution of the adjoint equation, we introduce new variables and use an implicit difference splitting scheme. The peculiarity of the developed numerical model is the possibility of operative estimation of the «vulnerability» zone near a possible attack objective. Findings. The developed numerical model and computer program can be used for scientifically grounded assessment of the «vulnerability» zone near significant facilities in the event of possible attacks with the use of chemical (biological) agents. The constructed numerical model can be implemented on computers of small and medium power, which allows it to be widely used to solve the problems of this class when developing the emergency response plan. The results of the computational experiment are presented, which allow us to evaluate the possibilities of the proposed numerical model. Originality. An effective numerical model is proposed for calculating the «vulnerability» zone near the facility, which may be the target of a terrorist attack with the use of a chemical agent. The model is based on the numerical integration of the velocity potential equation and the equation adjoint to the equation of mass transfer of a chemically dangerous substance in the atmosphere. Practical value. The developed model can be used to organize protective actions near the target facility of a possible chemical attack by terrorists.Item Development of a Method for Assessing Air Dustiness in the Main Fairing of the Launch Vehicle(PC Тесhnology Сеntеr, Kharkiv, Ukraine, 2022) Biliaiev, Mykola M.; Biliaieva, Viktoriia V.; Rusakova, Tetiana I.; Kozachyna, Vitalii A.; Berlov, Oleksandr V.; Semenenko, Pavlo; Kozachyna, Valeriia; Brazaluk, Iuliia; Klym, Viktoriia; Tatarko, LarysaENG: The object of this study is the process of thermostating the main fairing with a satellite at the stage of prelaunch preparation of the launch vehicle. When thermostating, it is necessary to predict the risk of dust contamination of the satellite surface. Currently, there are no normative methods for solving this problem. A numerical model has been proposed that makes it possible to quickly predict the dynamics of pollution of any surface of the satellite. A numerical model has been built for analyzing the zones of dust pollution of air in the main fairing of the launch vehicle during thermostating. The novelty of the model is the use of the Laplace equation for the speed potential, based on which the problem of aerodynamics is solved, namely, the flow rate in the main fairing is determined. Based on the model built, a computational experiment was conducted for dust particles with a diameter of 6 μm that fall into the main fairing during thermostating. The results of the research showed that the formation of areas of dust pollution near the satellite is influenced by the geometric shape of the satellite, which affects the formation of an uneven air velocity field in the main fairing and the organization of air supply to the main fairing. Calculations are performed within a few seconds, which makes it possible during working day to conduct a set of studies into the rational choice of the organization of air exchange of the main fairing during its thermostating. The constructed numerical model can be used in design organizations to scientifically substantiate the thermostating mode of the main fairing, taking into consideration the characteristics of the satellite located in it.Item Emergency Burning of Solid Rocket Propellant: Damage Risk Assessment to People in the Workplace(Dnipro National University of Railway Transport named after Academician V. Lazaryan, Dnipro, 2020) Biliaiev, Mykola M.; Berlov, Oleksandr V.; Biliaieva, Viktoriia V.; Kozachyna, Vitalii A.; Kalashnikov, Ivan V.EN: Purpose. This work includes the development of a computer model to calculate the risk of thermal damage to people in the shop in case of emergency burning of solid rocket propellant. Methodology. To calculate the temperature field in the shop in order to determine the zones of thermal damage to workers in the building, the equation expressing the law of energy conservation was used. Based on this modeling equation, the temperature field in the shop is calculated in the presence of a source of heat emission – burning solid rocket propellant. To calculate the velocity field of air flow in the shop, taking into account the location of obstacles in the path of heat wave propagation, we used the model of vortex-free air motion – the equation of the velocity potential. A two-step finite difference scheme of conditional approximation is used to numerically solve the equation for the velocity potential. A difference splitting scheme was used to numerically solve the energy equation. At the first stage of construction of the difference splitting scheme of the two-dimensional energy equation into the system of one-dimensional equations is performed. Each one-dimensional equation allows you to calculate the temperature change in one coordinate direction. The point-to-point computation scheme is used to determine the temperature. When conducting a computational experiment, the air exchange in the building is taken into account. The risk assessment of thermal damage to personnel in the building is performed for different probabilities of the place of emergency combustion of solid rocket propellant. Findings. Using numerical model prediction of the potential risk areas of thermal damage to staff in the shop for a variety of emergency situations was performed. Originality. A computer model for rapid assessment of the potential risk of damage to people in the shop in case of emergency burning of solid rocket propellant was constructed. Practical value. The authors developed a code that allows you to quickly simulate the temperature fields formation in the shop in case of emergency burning of solid rocket propellant and to identify potential areas of thermal damages to workers based on this information. The developed computer program can be used to assess the risk of thermal damage in the chemical industry in case of emergency.Item Experimental Study of the Intensity of Coal Dust Removal(Prydniprovs'ka State Academy of Civil Engineering and Architecture, Dnipro, Ukraine, 2023) Biliaiev, Mykola M.; Berlov, Oleksandr V.; Brazaluk, Yuliia V.; Kozachyna, Vitalii A.; Oladipo, Mutiu OlatoyeENG: Problem statement. Industrial sites where coal storages are located are intensive sources of dust pollution of the environment. There is an important problem of assessing the intensity of dust removal into the atmospheric air from polluted areas. Knowledge of the intensity of dust removal into the atmospheric air makes it possible to scientifically assess the impact of contaminated sites on the pollution of the environment and work zones at industrial sites. The solution to this problem can be obtained experimentally. The purpose of the article. An experimental study of the value of the air flow velocity at which the detachment of dust particles from the surface with coal begins and their removal into the air and the determination of the intensity of the emission of coal dust from the contaminated surface. Methodology. The intensity of removal of coal dust from the contaminated area was studied experimentally in laboratory conditions. The research was conducted on coal samples from DTEK “Pavlohradvuhillya”, grade “ДГ. During the research, the velocity of the air flow at which the process of movement of dust particles along the emission source began and the velocity of “detachment” of dust particles and their removal from the emission source were determined. At the second stage of experimental research, the intensity of removal of coal dust from the polluted area was determined. Scientific novelty. The values of the air velocity at which the removal of coal dust particles from the contaminated area begins were determined experimentally. The regularity of the intensity of the removal of coal dust depending on the velocity of the air flow over the contaminated area was obtained. Practical significance. The obtained experimental data make it possible to determine under which weather conditions there is a risk of dust formation and the removal of dust into the atmosphere. The empirical dependence obtained by processing experimental data can be used for a scientifically based assessment of the level of pollution of working areas at industrial sites where there are coal storage facilities. Conclusions. The value of the velocity of the air flow at which the movement of dust particles on the contaminated surface begins, as well as the value of the velocity of the air flow at which the removal of dust particles into the air begins, was determined experimentally. The resulting empirical model can be used to estimate environmental damage due to dust pollution of atmospheric air.Item Investigation of Admixture Sedimentation in the Horizontal Settler(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпро, 2016) Kozachyna, Vitalii A.EN: Purpose. Sedimentation by gravity is the most common and extensively applied treatment process for the removal of solids from water and wastewater and it has been used for over one hundred years. Sedimentation tanks are one of the major parts of a treatment plant especially in purification of turbid flows. Horizontal settlers are mainly used for purification of high quantity of water. In these tanks, the low speed turbid water will flow through the length of the tank and suspended particle have enough time to settle. Finding new and useful methods for calculating and increasing hydraulic efficiency of horizontal settlers is the objective of many theoretical, experimental and numerical studies. But currently used models and methods in Ukraine do not allow taking into account geometrical form and various design features. In this paper the numerical model was developed to evaluate the effectiveness of horizontal settler with modified structure. Methodology. Numerical model is based on: 1) equation of viscous fluid dynamics; 2) mass transfer equation. For numerical simulation the finite difference schemes are used. The numerical calculation is carried out on a rectangular grid. For the formation of the computational domain markers are used. Findings.The model allows obtaining the purification process in the settler with different form and different configuration of baffles. Originality. A new approach to investigate the mass transfer process in horizontal settler was proposed. This approach is based on the developed CFD model. The fluid dynamics model was used for the numerical investigation of flows and waste waters purification. To investigate influence of baffles on settler efficiency physical experiment was carried out. Practical value.The developed model has more capacity than the existing models in Ukraine. The developed model allows computing quickly the efficiency of water purification in settlers. The model is not computationally expensive. Calculation time of one variant of the problem takes few minutes.Item Mathematical Modeling of Shock Wave Interaction with Wagon(IOP Publishing, 2020) Khrutch, V. K.; Biliaiev, Mykola M.; Kozachyna, Vitalii A.; Berlov, Oleksandr V.; Kirichenko, Pavlo S.; Biliaieva, Viktoriia V.EN: In case of some accidents on railways there may be situations when the shock wave appears and interacts with different objects on the railway (wagons, cargo, buildings etc.). In these cases it is necessary to predict the possible effect of shock wave diffraction on the different objects. Study of these problems on the basis of physical experiments (laboratory experiment or field experiment) demand expensive and unique experimental facility. In some cases physical experiment can’t be set. That is why mathematical simulation plays the important role in solving problem connected with shock wave propagation. For practice it is necessary to have predictive quick computing mathematical models which allow to perform numerical experiment on the basis of non-powerful computers. Now, in Ukraine, there is a real deficit of mathematical models which allow to compute quickly shock wave interaction with different objects. The aim of this work was development of quick computing numerical model to simulate shock wave propagation and its interaction with the wagons. The model is based on the numerical integration of Euler equations which are written in integral form. To solve modeling equations difference scheme of splitting was used. Results of numerical modeling are presented.Item Modeling Coal Dust Dispersion from Pile with Protection Barriers(EDP Sciences, 2020) Biliaiev, Mykola M.; Biliaieva, Viktoriia V.; Berlov, Oleksandr V.; Kozachyna, Vitalii A.; Kirichenko, Pavlo S.; Oladipo, Mutiu Olatoye; Poltoratskа, ViktoriiaEN: Abstract. The results of laboratory studies to evaluate the effectiveness of barriers which are used to reduce dust pollution from the coal pile are presented. The use of the Г-shaped barrier, which is set differently near the coal pile model, has been studied. A numerical model is proposed to compute coal dust concentration in the air near the pile. The Navier–Stokes equations are used to model the wind flow over the coal pile. These equations are written in the variables "vorticity-stream function". To simulate the process of coal dust dispersion from the coal pile, the equation of convective-diffusion transfer of the passive impurity is used. For numerical integration of the modeling equations, difference schemes of splitting are used. Developed numerical model allows to perform numerical experiments taking into account the complex geometric shape of the pile and screens. The results of the computational experiments are presented.Item Modeling Influence of TiO2 Barrier Coating on Pollutant Dispersion Near Road(Kaunas University of Technology, 2023) Biliaiev, Mykola M.; Berlov, Oleksandr V.; Biliaieva, Viktoriia V.; Kozachyna, Vitalii A.; Kozachyna, Valeriia; Yakubovska, Zinaida M.ENG: Mitigation strategies for near-road air pollution are of great interest nowadays. Sound barriers near the road are very effective to decrease pollutant concentration. The use of titanium dioxide (TiO2) barrier coating provides additional effect which allows to decrease pollutant concentration near road. In this study quick- computing CFD model was developed to access influence of TiO2 barrier coating on pollutant concentration. To simulate wind flow over barrier with TiO2 coating model of potential flow was used. The process of NOx dispersion from car was computed using mass conservation equation. Finite-difference schemes were used for numerical integration of governing equations. The computer code was developed on the basis of proposed numerical model. Results of numerical simulations are presented.Item Modeling of Noise Pollution Near Railway(European Scientific Institute, ESI, 2020) Biliaiev, Mykola M.; Biliaieva, Viktoriia V.; Berlov, Oleksandr V.; Kozachyna, Vitalii A.EN: Noise from railway transport is a relevant problem from the point of view of people health. Now, in Ukraine, the railway traffic infrastructure has the period of development. It is important to predict railway transport noise impact in case of changing of transport infrastructure. Existing in Ukraine predictive models are based on empirical formulae which were obtained long ago for specific conditions and do not take into account some important factors. So, these models can’t be used for existing problems which are connected with railway transport noise. The aim of this work was development of numerical predictive model to forecast noise from railway transport. The model is built on the numerical integration of wave equation for acoustic pressure. Some results of numerical experiment are presented.Item Modeling of the Atmosphere Pollution From Coal Trains(Dnipro National University of Railway Transport named after Academician V. Lazaryan, 2019) Biliaiev, Mykola M.; Kozachyna, Vitalii A.; Biliaieva, Viktoriia V.; Oladipo, Mutiu Olatoye; Chernyatyeva, KaterynaEN: Abstract. Coal trains have an intensive impact on environment pollution. It is very important to predict adequately this impact during coal transportation. In Ukraine to predict atmosphere pollution from coal trains the regulatory model «OND-86» is used. This model does not take into account some important factors and coal train movement. We present numerical models to solve two problems:1) prediction of atmosphere pollution in the case of moving coal train; 2) prediction of atmosphere pollution in the case of additional special boards installation on the coal wagon. To solve these problems equation of coal duct convective- diffusive dispersion (Lagrange model of admixture dispersion) and equation of potential flow were used. Governing equations were numerically integrated using implicit difference schemes. For coding difference equations we used FORTRAN language. We present results of numerical experiments and laboratory experiments which illustrate the efficiency of the special additional boards installation on the coal wagon. These boards have «internal wing» and «external wing». The obtained results illustrate that installation of additional boards allows to minimize the atmosphere pollution near transport corridor.Item Numerical Determination of Horizontal Settlers Performance(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпропетровськ, 2015) Biliaiev, Mykola M.; Kozachyna, Vitalii A.EN: Purpose. Horizontal settlers are one of the most important elements in the technological scheme of water purification. Their use is associated with the possibility to pass a sufficiently large volume of water. The important task at the stage of their designing is evaluating of their effectiveness. Calculation of the efficiency of the settler can be made by mathematical modeling. Empirical, analytical models and techniques that are currently used to solve the problem, do not allow to take into account the shape of the sump and various design features that significantly affects the loyalty to a decision on the choice of the size of the settling tank and its design features. The use of analytical models is limited only to one-dimensional solutions, does not allow accounting for nonuniform velocity field of the flow in the settler. The use of advanced turbulence models for the calculation of the hydrodynamics in the settler complex forms now requires very powerful computers. In addition, the calculation of one variant of the settler may last for dozens of hours. The aim of the paper is to build a numerical model to evaluate the effectiveness of horizontal settling tank modified design. Methodology. Numerical models are based on: 1) equation of potential flow; 2) equation of inviscid fluid vortex flow; 3) equation of viscous fluid dynamics; 4) mass transfer equation. For numerical simulation the finite difference schemes are used. The numerical calculation is carried out on a rectangular grid. For the formation of the computational domain markers are used. Findings. The models allow calculating the clarification process in the settler with different form and different configuration of baffles. Originality. A new approach to investigate the mass transfer process in horizontal settler was proposed. This approach is based on the developed CFD models. Three fluid dynamics models were used for the numerical investigation of flows and waste waters purification. Practical value. The developed models have more capacity than the existing models in Ukraine. The developed models allow calculating quickly the efficiency of water purification in settlers. The models are not computationally expensive. Calculation time of one variant of the problem takes few seconds.Item Numerical Model for Evaluation Efficiency of Coal Pile Wetting(IOP Publishing Ltd, 2022) Biliaiev, Mykola M.; Biliaieva, Viktoriia V.; Kozachyna, Vitalii A.; Gunko, Olena Y.; Rusakova, Tetiana I.ENG: Problem statement. Wetting the surface of coal piles is a common method of reducing dust emissions. The purpose of the article. The aim of the paper is development of numerical model to assess effectiveness of coal pile wetting to reduce air pollution. Methodology. A two-dimensional mass transfer equation was used to model the process of coal dust distribution from the pile. This equation takes into account the convective and diffusion transport of coal dust in the atmosphere. A potential flow model was used to model the wind flow over the coal pile. Finite-difference splitting schemes have been used for numerical integration of modeling equations. Scientific novelty. The developed mathematical model takes into account different emission rates of coal dust from different parts of the coal pile. The model takes into account the effect of water evaporation from the coal pile on the rate of intensity of coal dust emission. Practical significance. Computer code based on the proposed numerical model has been developed. The developed code can be used to predict the efficiency of wetting coal piles over time. Conclusion. Two-dimensional numerical model was developed to evaluate the efficiency of coal pile wetting which is used to reduce coal dust concentration near pile. The model is focused on evaluation of the level of air pollution in the working areas near the coal pile. Developed numerical model takes into account geometrical form of coal pile and non-uniform wind velocity pattern. This numerical model uses some empirical models to describe mathematically relation between the dust emission rate and moisture.Item Numerical Model to Simulate Ventilation of Dead–End Mine Working with Brattice(EDP Sciences, 2020) Voloshyn, Oleksii I.; Biliaiev, Mykola M.; Biliaieva, Viktoriia V.; Kozachyna, Vitalii A.; Berlov, Oleksandr V.; Rusakova, Tetiana I.; Kalashnikov, Ivan V.EN: Abstract. A computational model to simulate ventilation of a dead-end mine working with line brattice has been developed. To solve fluid dynamics problem, i.e. to compute flow pattern, model of inviscid flow has been used. That allows to compute quickly air flow pattern. To simulate dust dispersion in the dead-end mine working with brattice two- dimensional equation of mass transfer has been used. Numerical integration of Laplas equation for the velocity potential has been carried out using Samarski two steps difference scheme of splitting. Proposed CFD model allows quick computing of dust dispersion in the dead-end mine working with brattice. Markers (porosity technique) have been used to create the complex geometrical form of computational domain. Results of numerical experiments which had been performed on the basis of the developed CFD model have been presented.Item Numerical Simulation of Toxic Chemical Transport after Accidental Release at Chemical Plant(Editura Academiei Romane, 2020) Biliaiev, Mykola M.; Biliaieva, Viktoriia V.; Kozachyna, Vitalii A.; Berlov, Oleksandr V.; Kalashnikov, Ivan V.EN: Abstract. Toxic chemical release may occur at different plants and impact directly on the people in the working areas. It is very important to predict atmosphere pollution and make risk assessment for accidental releases. CFD modeling is a powerful tool to solve these problems. This work is concerning on development of quick computing numerical model to predict air pollution in case of accidental solid propellant burning at the chemical plant. The model is based on transport equation for the products of propellant burning. Air flow on the industrial site is computed on the basis of potential flow model. To solve governing equations implicit finite difference schemes of splitting have been used. The results of numerical experiments are presented.Item Prediction of Atmospheric Air Pollution Near a Coal Stack in Adverse Weather Conditions(IOP Publishing Ltd, 2023) Biliaieva, Viktoriia V.; Berlov, Oleksandr V.; Kozachyna, Vitalii A.; Nochvai, Volodymyr; Yakubovska, Zinaida M.; Oladipo, Mutiu OlatoyeENG: Coal piles on the territory of enterprises are long-term sources of dust pollution of atmospheric air. Forecasting the level of dust pollution of the air for such objects is carried out, as a rule, for convection conditions. But during inversion, very high concentrations of dust can occur on industrial sites. The task of assessing the level of dust pollution of atmospheric air at an industrial site during dust emission in conditions of inversion from a coal stack is considered. A three-dimensional equation of convective-diffusion dispersion of contamination in atmospheric air, compatible with the approach of Prof. Berliand M. on determining the value of the vertical diffusion coefficient in the surface layer of the atmosphere for the case of inversion, to model dispersion of dust from a coal stack under inversion conditions is used. Numerical integration of the modeling equation of convective-diffusion transport of contamination is carried out on the basis of the splitting method compatible with the use of a locally one-dimensional finite-difference scheme. The results of a computational experiment to determine dust pollution zones at the Prydniprovsk thermal power station are presented.Item Quick Computing Numerical Model of Pollutant Dispersion in Urban Street Canyon(Kaunas University of Technology, Kaunas, 2022) Biliaiev, Mykola M.; Rusakova, Tetiana I.; Biliaieva, Viktoriia V.; Berlov, Oleksandr V.; Kozachyna, Vitalii A.; Kirichenko, Pavlo S.ENG: This research proposes a numerical model for the quick calculation of air pollution by emissions from cars in urban area such as "canyon". The Euler equations written in Helmholds variables were used to calculate the wind flow velocity field in street canyon. A special technique is used to calculate the vorticity in the corner points of buildings and barriers near the road. To calculate pollutant concentration field in the street canyon, which is formed from the traffic flow, the mass transfer equation was used, which took into account pollutant emission rate from cars, atmospheric diffusion, gravitational deposition, convective transfer. For numerical integration of modeling equations change-triangular finite-difference schemes were used The computer code realizing the developed numerical model was developed. The results of computational experiments to estimate the level of air pollution for different variants of the "canyon" scheme are presented.