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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.
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.
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.
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.
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
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.
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.
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 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.
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 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.
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.
Reducing of Coal Dust Release from Train Wagon with Barrier
(IOP Publishing, 2020) Biliaiev, Mykola M.; Biliaieva, Viktoriia V.; Kozachyna, Vitalii A.; Berlov, Oleksandr V.; Oladipo, Mutiu Olatoye; Kirichenko, Pavlo S.
EN: Intensive environment pollution takes place during coal transportation in open wagons. Emission of coal dust from the coal wagons cause contamination of atmosphere and territory adjacent to the railway track. Different ways to reduce coal dust emission from the wagon are used in the world. Unfortunately, in Ukraine, this problem is far from solution and there is no serious research work in this field. The aim of this work was laboratory study of coal dust emission from the wagon model which had different barriers installed on the wagon. Laboratory experiments were carried for coal wagon without barrier and for coal wagon which had barriers of two types. Barrier of the first type had downwind wing. Barrier of the second type had upwind wing. The contamination zones, concentration near the model were studied. The obtained results illustrate that installation of barriers influence intensity of transport corridor contamination. Also a numerical model was developed to estimate wind flow and coal dust dispersion from the coal wagon. Equation of potential flow and equation of coal dust dispersion were used. Implicit difference schemes of splitting were used for numerical simulation of governing equations. Results of numerical experiment, which were performed, are presented.
Risk Assessment in Case of Toxic Chemical Emission at Railway Transport
(Dnipro National University of Railway Transport named after Academician V. Lazaryan, 2019) Biliaieva, Viktoriia V.; Mashykhina, Polina B.; Kalashnikov, Ivan V.; Berlov, Oleksandr V.; Kravets, Ivan B.
EN: Abstract. Risk assessment during emission of toxic chemicals at railway transport is the problem of great scientific interest. To make such assessment we need special computer models. At present, in Ukraine,we have lack of such models. The authors present numerical models for territorial risk assessment in case of organized emissionsat railway transport (for example, emissions during locomotive movement) and in case of accident emissions (accident spills of dangerous cargo, emissions of NH3 from railway tank, etc.).The basis of the developed numerical models is the system of fundamental equations of fluid dynamics.These equations are solved numerically using implicit schemes of splitting. The developed models allow to take into account some important factors which influence the territorial risk value: probability of atmosphere conditions, train route, transport infrastructure at railway stations, probability of emission site.Also the process of pollutant chemical transformation in the atmosphere is taken into account in the developed models. The developed models allow to predict territorial risk in case of moving source of emission (moving damaged railway tank).The results of numerical experiments are presented. These results illustrate territorial risk maps for different sites near Prydniprovska railway.
Risk Assessment of Thermal Damage to People at Industrial Sites in Case of Emergency Burning Solid Propellant
(Дніпровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпро, 2020) Biliaiev, Mykola M.; Berlov, Oleksandr V.; Kozachyna, Vitalii A.; Kalashnikov, Ivan V.; Shevchenko, O. V.
EN: Purpose. This work involves the development of a numerical model for the calculation of areas of thermal damage to people in the event of solid propellant burning at the industrial site. Methodology. An equation expressing the law of energy conservation was used to solve the problem of determining the areas of thermal shock of people at the industrial site. A potential flow model was used to calculate the airflow velocity field in the presence of buildings at the industrial site where an emergency occurs. The numerical solution of the two-dimensional equation for the velocity potential is derived using the Liebmann method. This numerical model takes into account the uneven velocity field of the wind flow that is formed near industrial buildings. An implicit difference splitting scheme was used to numerically solve the energy equation. The physical splitting of a two-dimensional energy equation into a system of one-dimensional equations describing the temperature transfer in one coordinate direction has been carried out previously. At each splitting step, the unknown temperature value is determined by an explicit point-to-point computation scheme. Based on the numerical model built, the code using the FORTRAN algorithm language is created. Findings. Based on the developed numerical model, a computational experiment was conducted to evaluate the risk of thermal damage to people at the industrial site where solid propellants are produced. The dangerous areas for personnel are identified. Originality. An efficient numerical model has been developed to calculate the zones of thermal pollution in case of solid propellant burning. Practical value. Based on the developed mathematical model, a computer program was created, which allows performing serial calculations for determining the zones of thermal damage during emergencies at the chemically hazardous objects. The mathematical model developed can be used to design an emergency response plan for chemically hazardous objects.
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.
Simulation of Environmental Pollution from Diesel Locomotive
(IOP Publishing, 2020) Biliaiev, Mykola M.; Rusakova, Tetiana I.; Kozachyna, Vitalii A.; Berlov, Oleksandr V.; Poltoratskа, Viktoriia; Yakubovska, Zinaida M.
EN: Diesel locomotives are widely used at Ukrainian railway stations as maneuvering locomotives. Emissions from these diesel locomotives contain different toxic chemicals. It is important to understand air contamination patterns which are formed at railway stations. Understanding of these contamination patterns allows to evaluate the negative impact of diesel locomotive emissions on environment. To solve this problem it is necessary to use mathematical models which take into account the most important factors influencing formation of contamination zones. This paper introduces numerical model which allows to simulate pollutants dispersion from moving diesel locomotive. Developed numerical model is based on three dimensional equation of potential flow and three dimensional equation of pollutant dispersion. The model takes into account pollutants (NO, NO2) chemical transformation. To solve three dimensional equation of potential flow the implicit difference scheme of splitt ing was used. To solve three dimensional equation of pollutant dispersion the implicit difference scheme of splitting was used. Euler method was used to solve numerically equations of pollutant chemical transformation. Developed numerical model allows to take into account influence of buildings at the railway station on the contamination zones formation. Developed model consumes not much computer time. Results of performed numerical experiment are presented.

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