Кафедра "Гідравліка та водопостачання"

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3D Modeling of Biological Wastewater Treatment in Aeration Tank
(Дніпровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпро, 2020) Biliaiev, Mykola M.; Lemesh, Maksym V.; Gunko, Olena Y.; Zadoia, Viacheslav O.; Mashykhina, Polina B.; Yakubovska, Zinaida M.
ENG: Purpose. The main purpose of the article is to develop a 3D CFD model for modeling the process of biological wastewater treatment in an aeration tank. Methodology. For mathematical modeling of the process of biological wastewater treatment in the reactor, taking into account the flow hydrodynamics, geometric shape of the aeration tank, convective-diffusion transfer of the substrate and activated sludge, a 3D CFD model was built. The model is based on the three-dimensional equation of motion of an ideal liquid and the equation of mass conservation for the substrate, activated sludge. The field of sewage flow rate in the aeration tank is calculated based on the velocity potential equation. The process of biological transformation of the substrate is calculated on the basis of the Monod model. The splitting scheme was used for numerical integration of the equations of convective-diffusion transfer of activated sludge and substrate. The splitting is carried out in such a way to take into account the transfer of substrate (activated sludge) in only one direction at each step of splitting. The calculation of the unknown value of the substrate (activated sludge) concentration is carried out according to an explicit scheme. The Richardson method is used to numerically integrate the three-dimensional equation for the velocity potential, and the unknown value of the velocity potential is calculated by an explicit formula. Euler's method is used for numerical integration of equations describing the process of substrate transformation and change in activated sludge concentration (Monod model). Findings. The software implementation of the constructed 3D CFD model is carried out. A description of the structure of the developed software package is provided. The results of a computer experiment to study the process of wastewater treatment in an aeration tank with additional elements are presented. Originality. A new multifactor 3D CFD model has been developed, which allows quick assessing the efficiency of biological treatment in an aeration tank. Practical value. The constructed 3D CFD model can be used to analyze the efficiency of the aeration tank under different operating conditions at the stage of sketch design of wastewater treatment systems.
3D численная модель для оценки территориального риска при теракте
(Дніпропетровський національний університет залізничного транспорту ім. акад. В. Лазаряна, Дніпро, 2018) Беляев, Николай Николаевич; Калашников, Иван Владимирович; Клименко, Ирина Владимировна; Козачина, Виталий Анатольевич
RU: Цель. Работа предполагает разработку 3D численной модели для оценки территориального риска в случае теракта с использованием химического агента. Методика. Для описания процесса рассеивания в атмосфере химического агента, выброшенного в случае теракта, используется трехмерное уравнение массопереноса примеси в атмосферном воздухе. Уравнение учитывает поле скорости ветрового потока, атмосферную диффузию, интенсивность эмиссии химического агента, наличие зданий возле места выброса химически опасного вещества. Для численного интегрирования моделирующего уравнения используется конечноразностный метод. Особенностью разработанной численной модели является возможность оценки территориального риска в случае теракта при различных метеоусловиях и наличии зданий. Для расчета поля скорости ветрового потока в условиях застройки применяется трехмерное уравнение для потенциала скорости. Результаты. Разработанная численная модель и пакет программ могут быть использованы для оценки территориального риска как в случае терактов с применением химических агентов, так и в случае экстремальных ситуаций на химически опасных объектах и транспорте. Построенная численная модель может быть реализована на компьютерах малой и средней мощности, что позволяет широко использовать ее для решения задач рассматриваемого класса, при разработке плана ликвидации аварийной ситуации. Представлены результаты вычислительного эксперимента, позволяющие оценить возможности предложенного метода оценки территориального риска в случае теракта с использованием химического агента. Научная новизна. Предложена эффективная численная модель для оценки территориального риска в случае теракта с применением химически опасного вещества. Метод может быть использован для оценки территориального риска в условиях городской застройки, что позволяет получать адекватные данные о возможных зонах поражения. Метод основан на численном интегрировании фундаментального уравнения массопереноса, выражающего закон сохранения массы в жидкой среде. Практическая значимость. Предложенный метод оценки территориального риска в случае теракта с применением химического агента может быть использован для расчета зон поражения возле административных зданий, центров и других социально значимых объектов.
3D-розрахунок вертикального відстійника на базі CFD-моделі
(Вінницький національний технічний університет, 2012) Біляєв, Микола Миколайович; Нагорна, Олена Костянтинівна
UK: Розглянуто побудову чисельної моделі масопереносу у вертикальному відстійнику. Моделювання здійснено на основі тривимірного рівняння переносу домішки і моделі потенціального руху. Для чисельного інтегрування використано неявні різницеві схеми. Наведено результати обчислювального експерименту.
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, Pavlo
ENG: 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.
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.
Application of Local Exhaust Systems to Reduce Pollution Concentration Near the Road
(Silesian University of Technology, Katowice, Poland, 2020) Biliaiev, Mykola M.; Pshinko, Oleksandr M.; Rusakova, Tetiana I.; Biliaieva, Viktoriia V.; Sładkowski, Aleksander
EN: In this study, the methodological foundations of the technology for the local reduction of chemical pollution from vehicles were improved through the use of twolevel suction units and guide plates of various lengths installed on the nozzles of the suction devices. A program has been developed for the numerical calculation of the carbon monoxide concentration field for evaluating the efficiency of using two-level exhaust systems with different lengths of guide plates on the gas flow selection pipes. The solution of the equations of hydrodynamics and mass transfer is carried out on the basis of finite-difference methods. A number of physical and computational experiments have been carried out; it has been established that the concentration of carbon monoxide in the zone of two-level suctions location decreases by 46-68%.
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, Kateryna
EN: 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.
Atmosphere Protection in Case of Emergency During Transportation of Dangerous Cargo
(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпро, 2016) Berlov, Oleksandr V.
EN: Purpose. The paper highlights the development of numerical models for prediction of atmospheric pollution in case of burning of the solid rocket propellant in a railway car, situated near the building on railway territory. These models can be used in predicting the effectiveness of neutralization upon the atmosphere protection for this type of accidents. Methodology. To solve this problem the numerical models based on the use of Navier-Stokes equations, to determine the velocity field of the wind flow near cars and buildings, and contaminants-transfer equations in the atmosphere were developed. For the numerical integration of pollutant transport equation was used implicit «change – triangle» difference scheme. When constructing a difference scheme physical and geometric cleavage of the transfer equation is carried out in four steps. Unknown value of pollutant concentration at each step of cleavage is determined by the explicit scheme – the method of «point-to-point computation». For the numerical integration of the Navier-Stokes equations are used implicit difference schemes. When carrying out computing experiment also takes into account: the velocity profile of wind flow; interaction between the building and the wind flow and flame jet of solid rocket propellant; the presence of a railroad car; inside which there is a source of pollution; instability of pollutant emissions. On the basis of constructed numerical models was performed the computer experiment for assessing the level of air pollution at dangerous cargo rail transportation in case of emergency at railway territory.The application calculations for the timely combustion products neutralization of solid rocket propellant were carried out. Findings. The numerical models that let promptly calculate air contamination in case of emergency during solid rocket propellant transportation, as well as calculate the rational parameters of pollutant neutralization process were developed by the researcher. These models can be used for routine calculations of various accident scenarios simulation. Originality. Numerical models were developed; they take into account significant factors, influencing the pollutant dispersion process in the atmosphere. On their base a pollutant neutralization method was offered in emergency situations on the railway transport. Practical value. Efficient numerical models, so called «diagnostic models» were considered for the rapid calculation of the air pollution level and air protection technology in emergency situations, in particular, in the case of railway transportation the solid rocket propellant.
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.
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.
CFD моделирование аэроионного режима в рабочих зонах в условиях искусcтвенной ионизации воздуха
(Днепропетровский национальный университет железнодорожного транспорта имени академика В. Лазаряна, Днипропетровск, 2016) Беляев, Николай Николаевич; Цыганкова, Светлана Григорьевна
RU: Цель. Работа предполагает создание CFD модели расчета аэроионного режима в помещениях и в рабочих зонах при искусственной ионизации воздуха путем установки ионизатора внутри помещения с учетом наиболее существенных физических факторов, оказывающих влияние на формирование концентрационного поля аэроионов. Методика. Предложенная CFD модель расчета аэроионного режима в рабочих зонах при искусственной ионизации воздуха путем установки ионизатора внутри помещения основана на применении уравнений аэродинамики, электростатики и массопереноса. Уравнение массопереноса учитывает взаимодействие ионов различной полярности друг с другом и с частицами пыли. Расчет скорости движения воздушных потоков в помещении осуществлялся на основе модели потенциального течения, для чего было использовано уравнение Лапласа для функции тока. Для расчета дрейфа заряженных частиц под действием электрического поля использовалось уравнение Пуассона для электрического потенциала. При моделировании учитывались: 1) влияние геометрических характеристик рабочей зоны; 2) местоположение отверстий приточно-вытяжной вентиляции; 3) расстановка мебели и оборудования; 4) режим воздухообмена в помещении; 5) наличие препятствий в процессе рассеивания аэроионов; 6) конкретное место эмиссии частиц пыли и ионов различной полярности и их взаимодействие в помещении и в рабочих зонах. Результаты. Разработанная CFD модель позволяет определить концентрацию отрицательных ионов в помещении и в зоне расположения органов дыхания человека. Распределение концентрации отрицательных аэроионов представлено в виде изолиний концентрационного поля. Научная новизна. Авторами создана 2D CFD модель для расчета аэроионного режима в рабочих зонах, предоставляющая возможность определять концентрационное поле аэроионов в заданном месте в помещении. Предложенная модель разработана с учетом: размещения мебели и оборудования в помещении; геометрических характеристик помещения; местоположения источников эмиссии пыли и ионов различной полярности; физических процессов, влияющих на формирование концентрационного поля аэроионов. Практическая значимость. Полученная 2D CFD модель для расчета аэроионного режима в рабочих зонах позволит рассчитывать концентрацию аэроионов в месте расположения дыхательных органов человека с учетом основных физических факторов, определяющих формирование концентрационных полей аэроионов. Это даст возможность рационально расположить ионизаторы в рабочих помещениях для создания комфортных условий работы персонала.
CFD модель для оценки территориального риска и уровня загрязнения воздушной среды при эмиссии химического агента
(Национальный горный университет, Днепр, 2018) Беляев, Николай Николаевич; Калашников, Иван Владимирович; Берлов, Александр Викторович
RU: Предложен метод расчета распространения опасных веществ в условиях застройки, который позволяет осуществлять оценку территориального риска. Численное моделирование осуществляется на базе модели аэродинамики и распространения примеси в атмосферном воздухе. Численная модель ориентирована на проведение экспресс расчетов. Приведено описание алгоритма решения задачи по оценке территориального риска при эмиссии химически опасного вещества при экстремальной ситуации на промышленном объекте. Представлены результаты вычислительного эксперимента.
CFD моделювання в аналізі ефективності систем захисту довкілля та працівників на робочих місцях
(Журфонд, Дніпро, 2022) Біляєв, Микола Миколайович; Біляєва, Вікторія Віталіївна; Берлов, Олександр Вікторович; Козачина, Віталій Анатолійович
UKR: У моноrрафії розrлянуто питання розробки та оцінки ефективності систем захисту довкілля та працівників на робочих місцях від хімічноrо, шумовоrо, пиловоrо забруднень. Велику увагу приділено розробці математичних моделей для оцінки ефективності використання засобів захисту від пилового забруднення робочих зон біля транспортних маrістралей та на об'єктах rірничого комплексу. Представлено результати розрахунку процесу дифракції ударної хвилі після вибуху на залізнничній станції та забруднення атмосферноrо повітря при горінні ракетного палива.
Complex of Numerical Models for Computation of Air Ion Concentration in Premises
(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпропетровськ, 2016) Biliaiev, Mykola M.; Tsygankova, Svetlana G.
EN: Purpose. The article highlights the question about creation the complex numerical models in order to calculate the ions concentration fields in premises of various purpose and in work areas. Developed complex should take into account the main physical factors influencing the formation of the concentration field of ions, that is, aerodynamics of air jets in the room, presence of furniture, equipment, placement of ventilation holes, ventilation mode, location of ionization sources, transfer of ions under the electric field effect, other factors, determining the intensity and shape of the field of concentration of ions. In addition, complex of numerical models has to ensure conducting of the express calculation of the ions concentration in the premises, allowing quick sorting of possible variants and enabling «enlarged» evaluation of air ions concentration in the premises. Methodology. The complex numerical models to calculate air ion regime in the premises is developed. CFD numerical model is based on the use of aerodynamics, electrostatics and mass transfer equations, and takes into account the effect of air flows caused by the ventilation operation, diffusion, electric field effects, as well as the interaction of different polarities ions with each other and with the dust particles. The proposed balance model for computation of air ion regime indoors allows operative calculating the ions concentration field considering pulsed operation of the ionizer. Findings. The calculated data are received, on the basis of which one can estimate the ions concentration anywhere in the premises with artificial air ionization. An example of calculating the negative ions concentration on the basis of the CFD numerical model in the premises with reengineering transformations is given. On the basis of the developed balance model the air ions concentration in the room volume was calculated. Originality. Results of the air ion regime computation in premise, which is based on numerical 2D CFD model and balance model, are presented. Practical value. A numerical CFD model and balance model for the computation of air ion regime allow calculating the ions concentration in the premises in the conditions of artificial air ionization taking into account the main physical factors determining the formation of ions concentration fields.
Computer Modeling of Air Pollution in Case of Dust Cloud Movement in Open Pit Mine
(Dnipro National University of Railway Transport named after Academician V. Lazaryan, 2019) Biliaieva, Viktoriia V.; Kirichenko, Pavlo S.; Berlov, Oleksandr V.; Gabrіnets, Volodymyr O.; Horiachkin, Vadym M.
ENG: Purpose. Explosions in open pits lead to the formation of dust clouds. These clouds lead to intense air pollution. An important task is the development of methods for predicting the dynamics of atmospheric air pollution during ex-plosions in open pits. The purpose of this work is development of a numerical model to predict atmosphere pollution after explosion in open mine pit. The task is to develop a numerical model that would allow for the calculation to take into account the geometrical shape of the open pit mine, the parameters of the meteorological situation (wind speed, atmosphere), the shape of the dust cloud that is formed in the open pit mine at the site of the explosion. Methodology. Mathematical modeling of dust cloud dispersion during an explosion in an open pit mine is based on the use of fundamental equations of aerodynamics and mass transfer. The airflow velocity field in the open pit mine is modeled using the Laplace equation for the velocity potential. The formation of the concentration field of dust is mod-eled on the basis of the equation of convective-diffusion dispersion of an impurity. For numerical integration of model-ing equations, difference schemes are used. The Laplace equation for the velocity potential is numerically integrated using the Richardson method. For the numerical integration of the convective-diffusion dispersion equation for an im-purity, an implicit difference splitting scheme is used. Findings. A CFD model has been developed that allows you to calculate the formation of pollution zones during the movement of a dust cloud in the open pit mine. A feature of the developed model is the speed of calculation. For practical use of the developed model, standard input information is required. Originality. In contrast to the existing models in Ukraine, the developed numerical model allows taking into account the geometrical shape of the open pit mine and the geometrical shape of the dust cloud when making predictive calculations to assess the level of air pollution caused by explosions in open pits. Practical value. The developed nu-merical model can be implemented on computers of low and medium power. For practical use of the numerical model, standard information on meteorological conditions in open pit mine is required. The numerical model can be used for environmental assessment of the effect of explosions in open pit mine on environmental pollution and work areas.
Computer Simulation of Biological Wastewater Treatment Processes in Aerotanks With Plates
(Дніпровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпро, 2020) Biliaiev, Mykola M.; Lemesh, Maksym V.; Biliaieva, Viktoriia V.; Mashykhina, Polina B.; Yakubovska, Zinaida M.
EN: Purpose. Efficiency determination of the aeration tank at the stage of design or reconstruction of bioreactors in which biological wastewater treatment is carried out requires the use of special mathematical models and calculation methods. The main purpose of the article is to develop CFD models for evaluating the operation efficiency of aeration tanks. Methodology. A numerical model has been developed for the computer calculation of the biological wastewater treatment process in aerotanks, taking into account hydrodynamics. The model is based on two-level mass conservation equations for the substrate and activated sludge and the velocity potential equation. The process of biological transformation of the substrate is calculated based on the Monod model. For the numerical integration of the mass transfer equations of activated sludge and substrate, the alternating-triangular difference splitting scheme is used. In this case, the basic equations are divided into two equations of a more simplified form. For the numerical integration of the equations for the velocity potential, it is split into two one-dimensional equations. Further, each equation is solved according to explicit scheme. For the numerical integration of equations that describe the process of substrate transformation based on the Monod model, the Euler method is used. Findings. The software implementation of the constructed numerical model has been carried out. The results of a computational experiment on the study of the wastewater treatment process in an aeration tank with plates are presented. This leads to the conclusion that the quality control of wastewater treatment in aeration tanks is possible with the help of plates. Originality. A multivariate CFD model has been developed, which makes it possible to quickly assess the efficiency of the aeration tank. A feature of the model is the ability to evaluate the operation of the aeration tank, taking into account its geometric shape and location of additional plates in the construction. Practical value. The constructed numerical model can be used during calculations in the case of designing aeration tanks, or in determining the efficiency of wastewater treatment under new operating conditions.
Computer Simulation of Dead-End Mine Working Ventilation
(Dnipro National University of Railway Transport named after Academician V. Lazaryan, 2019) Biliaieva, Viktoriia V.; Kirichenko, Pavlo S.; Gunko, Olena Y.; Bondarenko, Iryna O.; Mashykhina, Polina B.; Yakubovska, Zinaida M.
ENG: Purpose. The important problem in the field of ecological safety and industrial safety is providing of normal microclimate in dead-end mine working. In these regions of the mine methane gas can be accumulated and as a result explosion may take place. So, to avoid these accidents it is important to ventilate appropriately dead-end mine working. The purpose of the work is development of quick computing mathematical model to obtain information about dead-end mine working ventilation process. Methodology. The process of dead-end mine working ventilation computing is separated in two stages. At the first stage the velocity flow field is computed in the dead-end mine working. We consider the situation when the suction tube is situated in this region. To solve this problem the fluid dynamics model of inviscid gas flow was used. At the second stage of the computational modeling the convective-diffusive equation of admixture transfer was used. The equation takes into account non-uniform flow field in the dead end mine workings. Findings. The developed numerical model was coded using FORTRAN language. The developed computer code allows to perform numerical experiment to assess the efficiency of suction tube imple-mentation to decrease methane gas concentration in dead-end mine working. Originality. The developed numerical model takes into account physical factors, which are not considered nowadays in the empirical models, which are used for solving the problems of dead-end mine working ventilation. It allows taking into account the geometrical form of the dead-end mine working. Practical value. The developed computer program allows to perform calculations to assess the efficiency of suction system used for the ventilation of the dead-end mine working.
Computing Model for Simulation of the Pollution Dispersion Near the Road with Solid Barriers
(Silesian University of Technology, Gliwice, Poland, 2021) Biliaiev, Mykola M.; Pshinko, Oleksandr M.; Rusakova, Tetiana I.; Biliaieva, Viktoriia V.; Sładkowski, Aleksander
ENG: In this study, a numerical model is proposed for calculating pollution zones near the road, taking into account the geometry of the automobile transport, meteorological conditions, the location of the barriers and their height, and the chemical transformation of nitrogen oxides in the atmospheric air. The numerical solution is based on the integration of the mass transfer equations using the finite-difference method. To determine the components of the air flow velocity vector, a two-dimensional model of the potential flow is used, where the Laplace equation for the velocity potential is the modeling equation. Based on this numerical model, a software package has been developed that allows computational experiments and does not require large expenditures of computer time. Based on the results obtained, an assessment was made of the effectiveness of the use of barriers to reduce the level of air pollution near highways. It has been established that the use of barriers of different heights reduces the level of pollution behind the road by approximately 20-50%.
Constructing a Method for Assessing the Effectiveness of Using Protective Barriers Near Highways to Decrease the Level of Air Pollution
(ПП ТЕХНОЛОГІЧНИЙ ЦЕНТР, Харків, 2021) Biliaiev, Mykola M.; Kozachyna, Vitalii A.; Biliaieva, Viktoriia V.; Rusakova, Tetiana I.; Berlov, Oleksandr V.; Mala, Yuliia
ENG: Highways are an intensive source of environmental pollution. Atmospheric air is exposed to the fastest anthropogenic influence. Therefore, a particularly important task is to minimize the level of air pollution near the highway. An effective method for solving this problem is the use of protective barriers of various shapes installed near highways. At the stage of designing these protective structures, an important task arises to assess their effectiveness. Estimation of the effectiveness of protective barriers by the method of the physical experiment takes considerable time to set up and conduct an experiment, as well as analyze the results of hysical modeling. This method is not always convenient during design work. An alternative method is the method of mathematical modeling. For the designer, it is very important to have mathematical models that make it possible to quickly obtain a predictive result and take into consideration a set of important factors on which the effectiveness of the protective barrier depends. A method has been devised that makes it possible to assess the effectiveness of using protective barriers to reduce the level of air pollution near the highway. It was found that an increase in barrier height by 80 % leads to a 22 % decrease in the concentration of impurities behind the barrier. It was established that applying a barrier with a height of 1.5 m leads to a 26 % decrease in the concentration of impurities in buildings adjacent to the highway. A method has been devised to assess the effectiveness of using absorbent "TX Active" surfaces on the protective barrier located near the highway. This study's result revealed that the application of a barrier with one "TX Active" surface leads to a decrease in the concentration of NO behind the barrier by an average of 43 %. When using a barrier with two "TX Active" surfaces, a decrease in the NO concentration behind the barrier is 85 % on average.
Determination of Areas of Atmospheric Air Pollution by Sulfur Oxide Emissions from Mining and Metallurgical and Energy Generating Enterprises
(ДВНЗ "Національний гірничий університет", м. Дніпро, 2017) Biliaiev, Mykola M.; Rusakova, Tetiana I.; Kolesnik, Valerіy Ye.; Pavlichenko, Artem V.
EN: Purpose. Development of methods and software for determining levels and zones of atmospheric air pollution by emissions from mining and power generating companies that contain significant volumes of sulfur oxides. Methodology. The forecast of the level of atmospheric air pollution by sulfur-containing emissions from mining and power generating companies is based on a mathematical model for calculating the concentration of sulfur dioxide, which takes into account the processes of its oxidation, as well as the formation and evaporation of sulfuric acid in the atmosphere. The numerical method is based on the joint solution of the equations of convective-diffusion transport of pollutants that come directly from enterprises or are formed additionally due to chemical reactions in the atmosphere. The technique is implemented using implicit difference schemes. Findings. The developed methodology and software allow predicting the levels of atmospheric air pollution by large industrial enterprises taking into account chemical transformations of sulfur oxides in the environment. A number of numerical experiments have been carried out to estimate the levels and zones of atmospheric air pollution in the city of Dnipro with sulfur dioxide near industrial enterprises, taking into account various meteorological conditions. Originality. The regularities of atmospheric air pollution by sulfur-containing emissions from industrial enterprises are established on the basis of a joint solution of transport process equations as for impurities coming from sources of pollution and transformation as a result of chemical reactions in the atmosphere. Practical value. The developed forecast method and software allow determining the concentration of pollutants in the atmosphere and assessing the level of environmental hazard of large industrial enterprises. The obtained patterns of dispersion of sulfur oxides make it possible to predict pollution levels of environmental objects on the territory of industrial cities and to introduce air protection measures in a timely manner.
Determining Zones of Chemical Pollution in the Citiesand Assessment of Chronic Diseases Risks
(Дніпровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпро, 2019) Biliaev, Mykola M; Rusakova, Tetiana I.
EN: Purpose. The scientific paper is aimed at creating a methodology of chemical pollution zones in the territories of industrial cities and accounting the possibility of assessing the risks of chronic diseases. Methodology. The method of numerical calculation of nitrogen dioxide concentration in atmospheric air is based on the solution of three-dimensional impurity transfer equations, which directly comes from a permanently stationary source (industri-al enterprise) and a linearly distributed source (highway). The method takes into account the process of chemical transformation of impurities and photolysis in the atmosphere. The numerical model is based on the splitting of model equations and their solution using an implicit difference scheme. Findings. The created software allows con-ducting computational experiments to calculate the areas of atmospheric air pollution with nitrogen dioxide, taking into account the interaction of impurities coming from various types of pollution sources and meteorological para meters. On the basis of the obtained field of nitrogen dioxide concentration, an assessment of the change in the risk of chronic intoxication associated with atmospheric air pollution with nitrogen dioxide over 50 years was carried out. Originality. For the first time the regularities of changes in the level of atmospheric air pollution with nitrogen dioxide have been established with due regard to the mutual influence of emissions from the industrial enterprise and highway and their chemical transformation in the atmosphere. The risk of chronic intoxication has been calcu-lated and its changes have been analyzed with due regard to the interaction of emissions from the industrial enter-prise and highway, it leads up to 10% of risk increasing. Practical value. Authors developed a mathematical model and method of numerical calculation. Software created on their base allows obtaining quickly quantitative results necessary in developing the system for monitoring the man-made loaded regions of the city. The obtained patterns of impurities dispersion allow us to estimate the levels of pollution in urban areas of the city by emissions from in-dustrial enterprises and highways. Accounting of the mutual impact of emissions and the calculation of risks of in-toxication allows solving environmental problems arising in the development of transport strategy in cities.
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, Larysa H.
ENG: 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.
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.
Expert Systems for Assessing Disaster Impact on the Environment
(Springer, 2014) Biliaiev, Mykola M.; Rostochilo, Natalia V.; Kharytonov, Mykola M.
EN: This paper presents expert systems and the numerical models to simulate atmosphere pollution after accidents with toxic substances. The expert systems allow one to assess impact on the person or environment after accidents of different types at chemical enterprises or storages. The process of toxic gas dispersion in the atmosphere is computed using the convective-diffusive equation. To compute the flow field among the buildings, two fluid dynamic models are used. The first fluid dynamic model is based on the 3-D equation of the potential flow. The second fluid dynamic model is based on the 2-D equations of the inviscid separated flows. To solve the convective-diffusive equation of the toxic gas dispersion in the atmosphere, the implicit change-triangle difference scheme is used. To solve the equations of the fluid dynamic models the A.A. Samarski’s difference scheme of splitting and change-triangle scheme are used. The developed numerical models have two submodels. The first submodel was developed to simulate the process of the atmosphere pollution after the accident spillages and the evaporation of the toxic substance from the soil. The second submodel allows predicting the air pollution inside the rooms in the case of the outdoor toxic gas infiltration into the room. The developed systems allow assessing the safety of the evacuation route. The developed expert system can be used to solve some specific problems such as the assessment of efficiency of protection measures which are developed to reduce the negative impact on the environment.
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.
Mathematical Modeling of Aeroion Mode in a Car
(The Silesian University of Technology, Katowice, Poland, 2022) Biliaiev, Mykola M.; Pshinko, Oleksandr M.; Rusakova, Tetiana I.; Biliaieva, Viktoriia V.; Sładkowski, Aleksander
ENG: Summary. In this study, a mathematical method is proposed for calculating the concentration field of air ions of different polarities and dust levels in the passenger compartment, taking into account the geometry of the passenger compartment and seats, shelves, and other internal elements of the passenger compartment. The method also takes into account changes in the rate of the air flow ventilation, the location and number of ionizers, and sources of positive ions and dust, taking into account their different intensities and locations. On the basis of a numerical model for this method, software has been developed that allows users to carry out computational experiments without requiring much time for calculation. Based on the results, the optimal location of the ionizer in the passenger compartment of the car was determined to ensure comfortable conditions for the stay of passengers, which favorably affects their health. It has been found that the presence of two ionizers is optimal for creating comfort in the car with an ionization intensity of ions/s located at the top of the car. If there is one ionizer located on the dashboard or at the top of the car with a higher ionization rate than ions/s, it is not possible to simultaneously provide optimal ionization parameters for passengers in the front and rear seats of the car.
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.
Minimization of Environment Pollution from Coal Trains (dissertation)
(Dnipro National University of Railway Transport named after Academician V. Lazaryan, 2020) Oladipo, Mutiu Olatoye
ENG: The dissertation is devoted to the development of methods for minimizing the level of environmental pollution from dust pollution during coal transportation by rail. The transportation of coal from its production sites is carried out in coal wagons. In this case intensive environment pollution takes place. The analysis of modern methods of minimizing environmental pollution caused by coal dust showed that they require quite high costs, the use of additional equipment at stations of loading (unloading) of coal, much time for implementation. Analysis of scientific publications has shown the need to create effective and low cost methods of environment protection from pollution during the transportation of coal by rail. It is known that the intensity of dust pollution during coal transportation depends on many factors, the most important of which is the speed of the air near the surface of the cargo (local air flow speed). Therefore, to reduce the intensity of coal dust emission from the wagon, in this dissertation, some tools were selected that reduce the value of the local air flow speed near the surface of the coal. For this purpose it is offered to use special additional boards on the coal wagon and screens. In this dissertation on the basis of experimental and theoretical researches it is shown that application of additional boards of the special form ("vertical wall", "wing", "internal wing") and screens reduces coal dust removal from a wagon. On the basis of the performed experiments the regularities of dust zones formation on the underlying surface, both for coal wagon without and with additional boards or screens, were established. To determine the effectiveness of special boards, the screen application on the coal wagon a set of numerical models was developed. The models allow to predict air pollution in the case of coal transportation in wagons and when effectiveness of proposed means of environment protection. Modeling of dust air pollution during coal transportation in wagon is carried out on the basis of multidimensional differential mass transfer equations. Modeling of pollution process on the basis of these equations allows to obtain information about the formation of the coal dust concentration field in the whole study area, and not only at some point in the environment. The developed models allow to predict the level of atmosphere dust pollution taking with account of physical factors which were not previously taken into account in research works in this field, namely: geometric shape of additional boards, air flow speed near the cargo surface, coal dust emission rate, coal dust diffusion, wagon speed. It was shown that use of air curtain at the coal wagon allows to reduce dust pollution of environment during coal transportation. The practical value of the work is that the proposed methods of environment protection during the coal transportation require low economic costs for implementation. The manufacture of additional boards and screens can be performed using standard industrial equipment. The implementation of the proposed methods of protection does not require the installation of special equipment at loading stations (places of unloading), and does not require special retraining of workers. The effectiveness of the proposed methods of protection against environment dust pollution does not depend on climatic conditions. The developed numerical models allow to predict quickly the concentration of coal dust in the air, taking into account the main physical factors influencing the process of dust pollution. These models make it possible to reduce the share of physical experiment during research study in this scientific field. The experimental results obtained were compared with the theoretical ones obtained on the basis of the developed numerical models. The developed numerical models were also verified. Developed numerical models and methods of environmental protection are used in firm "Energoservice-KR" to develop technology to protect air from pollution during transportation of iron ore and coal, as well as in the educational process of the Dnipro National University of Railway Transport named after Academician V. Lazaryan.
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.
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, Viktoriia
EN: 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.
Modeling of Biological Wastewater Treatment on the Basis of Quick-Computing Numerical Model
(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпро, 2018) Biliaiev, Mykola M.; Lemesh, Maksym V.
EN: Purpose. The scientific paper involves the development of quick computing numerical model for prediction of output parameters of aeration tank. The numerical model may be used in predicting the effectiveness of aeration tank under different regimes of work. Methodology. To simulate the process of biological wastewater treatment in aeration tank numerical models were developed. The flow field in the aeration tank is simulated on the basis of potential flow model. 2-D transport equations are used to simulate substrate and sludge dispersion in the aeration tank. To simulate the process of biological treatment simplified model. For the numerical integration of transport equations implicit difference scheme was used. The difference scheme is built for splitting transport equations. Splitting of transport equation into two equations is carried out at differential level. The first equation of splitting takes into account the sludge or substrate movement along trajectories. The second splitting equation takes into account the diffusive process of substrate or sludge. To solve the splitting equations implicit difference scheme was used. For the numerical integration of potential flow equation the implicit scheme of conditional approximation was used. On the basis of constructed numerical model computer experiment was performed to investigate the process of biological treatment in aeration tank. Findings. Quick computing numerical model to simulate the process of biological treatment in the aeration tank was developed. The model can be used to obtain aeration tank parameters under different regimes of work. The developed model takes into account the geometrical form of the aeration tank. Originality. The numerical model which takes into account the geometrical form of aeration tank and fluid dynamics process was developed; the model takes into account substrate and sludge transport in aeration tank and process of biological treatment. Practical value. Efficient numerical model, so called «diagnostic models» was proposed for quick calculation of biological treatment process in aeration tank.
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.
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, Kateryna
EN: 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.
The Numeric Forecast of Air Pollution Caused by a Blasting Accident in the Enterprise Responsible for Rocket Fuel Utilization in Ukraine
(Springer Netherlands, 2013) Biliaiev, Mykola M.; Kharytonov, Mykola M.
EN: A mathematical model which can take into account all the scenarios of accidents has been developed. The code AIR-SIM was worked out on the basis of the described difference schemes. This code was used to simulate the atmospheric pollution for different accidents on the territory of the Pavlograd Chemical Plant. In particular, a numerical model was used to predict the atmospheric pollution in the case of HCN emission from the opening at the roof of the building. During the numerical experiment the dynamic of the toxic dose in each room was determined for each case study. It was established that the hitting zone will be about 6 km. © Springer Science+Business Media Dordrecht 2013.
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.
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.
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.
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.
Numerical Simulation of Air Pollution in Case of Unplanned Ammonia Release
(Dnipropetrovsk National University of Railway Transport named after Academician V. Lazaryan, Dnipro, 2017) Amelina, Larysa V.; Biliaiev, Mykola M.
EN: Purpose. Development fast calculating model which takes into account the meteorological parameters and buildings which are situated near the source of toxic chemical emission. Methodology. The developed model is based on the equation for potential flow and equation of pollutant dispersion. Equation of potential flow is used to compute wind pattern among buildings. To solve equation for potential flow Samarskii implicit difference scheme is used. The implicit change – triangle difference scheme is used to solve equation of mass transfer. Numerical integration is carried out using the rectangular difference grid. Method of porosity technique («markers method») is used to create the form of comprehensive computational region. Emission of ammonia is modeled using Delta function for point source. Findings. Developed 2D numerical model belongs to the class of «diagnostic models». This model takes into account the main physical factors affecting the process of dispersion of pollutants in the atmosphere. The model takes into account the influence of buildings on pollutant dispersion. On the basis of the developed numerical models a computational experiment was carried out to estimate the level of toxic chemical pollution in the case of unplanned ammonia release at ammonia pump station. Originality. Developed numerical model allows to calculate the 2D wind pattern among buildings and pollutant dispersion in the case unplanned ammonia release. Model allows to perform fast calculations of the atmosphere pollution. Practical value. The model can be used when developing the PLAS (Emergency Response Plan).
Numerical Simulation of Air Pollution in Workplaces After Toxic Chemical Emission
(Приднепровская государственная академия строительства и архитектуры, Днепр, 2017) Biliaiev, Mykola M.; Amelina, Larysa V.; Stepanova, Yu. O.
EN: Purpose. Development of a numerical model to compute the dynamics of atmosphere pollution in workplaces after accidents which results in toxic chemical emission. Methodology. For the numerical simulation of atmosphere pollution in workplaces 3D equation of pollutant dispersion is used. This equation takes into account the convective and dispersion processes of pollutant transport, the rate of toxic chemical emission, position of source emission. For the numerical integration of the governing equation of pollutant dispersion in atmosphere the implicit finite-difference scheme is used. On the basis of the numerical model generic model was developed FORTRAN language was used to develop the generic model. Computational experiments were carried out to calculate the dynamics of pollution after accident emission at ammonia pipeline which is situated at Dnepr River. Findings. The proposed model allow s to simulate the atmosphere pollution in workplaces alter accident emission of toxic chemicals. The model allows quickly obtain the information which can be used for response methods development. Results of numerical experiments are presented. Originality. 3D numerical model was developed allowing to calculate quickly atmosphere pollution after accidents which result in toxic chemical emission. Practical value. The developed model can be used for numerical simulation of air pollution in workplaces after toxic chemicals emissions. It can be used at the stage of PLAS (ПJIAC) development.