2019
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Browsing 2019 by Author "Biliaiev, Mykola M."
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Item Minimization of the Chemical Pollution Level at the Working Zones in Open Areas Using Screens(Дніпровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпро, 2019) Biliaiev, Mykola M.; Rusakova, Tetiana I.; Shynkarenko, Viktor I.ENG: Purpose. The scientific work aims to develop a new method for assessing the level of chemical air pollution in working zones located in open areas near highways using screens of different heights. Methodology. The analytical method for calculating the airflow velocity field near protective screens is based on the mathematical apparatus of the theory of complex variable functions, which allows obtaining the value of the velocity potential and the flow function, to calculate the velocity value at any point of the plane with a screen of different height. The obtained velocity field is used to calculate the level of carbon monoxide concentration in the numerical solution of the two-dimensional mass transfer equation. Findings. The developed program of numerical calculation allows conducting computational experiments on the effectiveness of the use of protective screens, taking into account changes in their geometry and meteorological conditions. The developed method based on the obtained concentration field makes it possible to carry out an assessment of the risk of chronic intoxication for the employees of the take-out trade, who are within the zone of the emission source (highway) for a long time. Originality. The regularities of changes in the concentration of carbon monoxide are established depending on the distance to the emission source at a height of 2 m from the ground in the presence of a screen of a certain height and in its absence. A risk assessment of chronic carbon monoxide intoxication has been carried out for take-out trade workers near the highway. It is shown that the presence of the screen reduces the risk of chronic CO intoxication by 10% as compared to its absence. Increasing the screen height to 1.8 m reduces the risk of chronic intoxication by 6% relatively to the situation when the screen height is 1.2 m. Practical value. The developed numerical-analytical method for calculating the level of chemical pollution in working zones in open areas and the program «Screen» created on its basis allow us to carry out a prompt forecast of atmospheric air pollution level with carbon monoxide taking into account the effectiveness of the screens. Quantitative results are necessary at the planning stage of trading places near highways, during the architectural-planned reorganization of adjacent developments.Item Numerical Modeling of Air Pollution From Dumps(Дніпровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпро, 2019) Biliaiev, Mykola M.; Rusakova, Tetiana I.; Kalashnikov, I. V.; Bondarenko, Iryna O.; Gunko, Elena Yu.ENG: Purpose. Rock dumps are long-term sources of air pollution. A significant amount of harmful substances enters the atmosphere. Particularly intense is the pollution of atmospheric air due to dusting dumps. An important task is the development of methods for predicting the dynamics of atmospheric air pollution during the emission of harmful impurities from dumps. When developing methods for predicting the dynamics of air pollution from dumps. It is very important to create a universal model that would allow on a single computing platform to calculate the process of atmospheric air pollution for various impurities that are released from dumps. Another important problem is the choice of the place for optimal placement of future dumps in order to minimize their negative impact on the environment. Methodology. Numerical modeling of the formation of atmospheric pollution zones near rock dumps is based on the application of the equation of turbulent dispersion of an impurity in the atmosphere. To solve the problem of choosing the rational location of the dumps, the conjugate equation is used. Numerical integration is carried out using an implicit difference scheme. Findings. Numerical models are developed. The first numerical model allows one to evaluate the effect of rock dumps on air pollution. The second numerical model allows, on the basis of a one-time calculation, to determine the rational location of the future dump from the point of view of its minimal impact on air pollution. Originality. Two numerical models are proposed that are based on the application of the turbulent diffusion equation and the conjugate equation. These models make it possible to quickly determine the effect of rock dumps on air pollution. The models take into account the convective transport of the pollutant, atmospheric turbulent diffusion, the intensity of the emission of impurities from the dump. Practical value. The developed numerical models are implemented in the form of program codes. These program codes can be used when performing serial calculations on computers of low and medium power, i.e. computer technology, which is available to organizations involved in environmental issues in technologically saturated regions. When carrying out calculations based on the constructed numerical models, typical initial data are used regarding the intensity of the emission of impurities from dumps, weather conditions characteristic of a specific region of the country.Item Prediction of Atmosphere Pollution in Case of Emissions From Main Mine Fans(Dnipro National University of Railway Transport named after Academician V. Lazaryan, 2019) Biliaiev, Mykola M.; Bondarenko, Iryna O.; Rusakova, Tetiana I.; Shynkarenko, Viktor I.; Gabrіnets, Volodymyr O.ENG: Purpose. Emissions from mine ventilation system can create intensive atmosphere air pollution. As a rule, a huge amount of dust from mine fan enters atmosphere low layers. An important task is the development of methods to assess levels of the atmosphere pollution near mines and settlements. To solve this problem it is important to have physically proved mathematical models. Nowadays to predict the atmosphere pollution near settlements which are effected by mine fan the empirical model OND–86 is used. This model does not take into account many important physical factors. So, the purpose of this study is the development of quick computing mathematical model to predict the atmosphere pollution in case of dust emissions from mine fan. Methodology. To predict levels of the atmosphere pollution in case of mine fan work 3D equation of dust convective – diffusive flow was used. This equation takes into account gravity fallout, wind velocity, atmosphere turbulent diffusion, location of dust emission source. To sole modeling equation the implicit difference scheme of splitting was used. Findings. Developed mathematical model allows quick prediction of the level of atmosphere pollution in case of dust emissions from mine ventilation fan. The models allow to obtain zones of contamination near settlements which are situated in vicinity of mine. Originality. The developed mathematical model takes into account a number of physical factors, which at the present time are not considered on the days when prediction of the atmosphere pollution in settlements near mine is carried out. Practical value. On the basis of the developed mathematical model program code was created. This code can be used for evaluation of atmosphere pollution in settlements which are effected mine fan emissions.Item Risk Assessment With the Use of the Monte-Carlo Method(Дніпровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпро, 2019) Amelina, Larysa V.; Biliaiev, Mykola M.; Berlov, Oleksandr V.; Cherednychenko, L. A.EN: Purpose. This work involves the development of a numerical model for the calculation of chemical contamination zones in the event of ammonia accident at the pumping station, as well as a model for assessing the risk of damage and wound depth in the body in case of fragments scattering formed during the pipeline explosion at the pumping station. Methodology. To solve this problem, we used the mass transfer equation for the ammonia propagation in the air. A potential flow model is used to calculate the air flow velocity field in the presence of buildings at the ammonia pumping station. The numerical solution of the three-dimensional equation for the velocity potential is derived by the cumulative approximation method. When using this numerical model, the irregular field of wind flow velocity, the change in vertical atmospheric diffusion coefficient with altitude, the ammonia emission intensity, the emission point of the chemical substance were taken into account. A differential splitting scheme was used to numerically solve the ammonia transfer equation in the air. Physical splitting of the three-dimensional mass transfer equation to a system of equations describing the contaminant transfer in one coordinate direction is carried out beforehand. At each step of splitting, the unknown value of ammonia concentration is determined by an explicit scheme of point-to-point computation. A mathematical model for calculating the fragments scattering in case of emergency at the pumping station is considered. Findings. On the basis of the developed numerical model, a computational experiment was conducted to estimate the level of air pollution at the ammonia pumping station. The area of possible damage of people during the fragment scattering during the explosion at the ammonia pumping station was determined. Originality. A numerical model has been developed that allows calculating the chemical contamination zones in case of emergency ammonia emission at the pumping station. The model is complemented by assessment of impact zones in case of fragment scattering during the pumping station explosion. Practical value. Based on the developed mathematical model, a computer program was created, which allows performing serial calculations for determining the impact zones during emergency situations at the chemically hazardous objects. The mathematical model developed can be used to perform serial calculations during the development of emergency response plan for chemically hazardous objects.