Science and Transport Progress

9-18

Authors: V. I. Havryliuk, O. M. Voznyak, V. V. Meleshko

Purpose. In the paper it is necessary to analyze possibility of improving the positioning accuracy of train on the approach section to crossing for traffic safety control at railway crossings. Methodology. Researches were performed using developed mathematical model, describing dependence of the input impedance of the coded and audio frequency track circuits on a train coordinate at various values of ballast isolation resistances and for all usable frequencies. Findings. The paper presents the developed mathematical model, describing dependence of the input impedance of the coded and audio-frequency track circuits on the train coordinate at various values of ballast isolation resistances and for all frequencies used in track circuits. The relative error determination of train coordinate by input impedance caused by variation of the ballast isolation resistance for the coded track circuits was investigated. The values of relative error determination of train coordinate can achieve up to 40-50 % and these facts do not allow using this method directly for coded track circuits. For short audio frequency track circuits on frequencies of continuous cab signaling (25, 50 Hz) the relative error does not exceed acceptable values, this allow using the examined method for determination of train location on the approach section to railway crossing. Originality. The developed mathematical model allowed determination of the error dependence of train coordinate by using input impedance of the track circuit for coded and audio-frequency track circuits at various frequencies of the signal current and at different ballast isolation resistances. Practical value. The authors proposethe method for train location determination on approach section to the crossing, equipped with audio-frequency track circuits, which is a combination of discrete and continuous monitoring of the train location.

30-38

Authors: M. M. Biliaiev, L. Ya. Muntian

Purpose. The present research is aimed to the development of a method to assess the potential territorial risk in accidents on the railways, which takes into account the specificity of the chemically hazardous substances emission in emergency situations during their transportation. Methodology. The basis of the proposed method is numerical modeling of the transfer process is chemically dangerous substances in the atmosphere. The basis of the numerical model is the equation of convective-diffusion transfer of chemically hazardous substances. This equation takes into account the dispersion in atmosphere of dangerous substances due to wind and atmospheric diffusion. For the numerical integration of the equations of transfer of chemically hazardous substances in the atmosphere is applied an implicit finite-difference scheme of splitting. Based on the constructed numerical model was developed method for the assessment of potential territorial risk and generated code in algorithmic language Fortran. The developed method of spatio-temporal risk assessment takes into account: the territorial probable weather situations; emission mode of chemically hazardous substances; emission power; the movement of the source of emission. A computational experiment to assess the level of air pollution above the village Sinelnikovo during the emergency leak of ammonia was conducted. Findings. The proposed method allows calculating quicklythe potential risk of the leakage of chemically hazardous substances on the basis of the calculation of the level of pollution in different meteosituation. The method allows determining the size of the zone of toxic casualties and assessing the level of risk of accidents in railway transport. Using the developed numerical model evaluated the assessment of risk of casualties in the residential area of the village Sinelnikovo. Originality. The scientists established the method for the assessment of potential territorial risk, based on the numerical modeling of air pollution. The calculation of potential risk to residential areas of the village Sinelnikovo was executed. Practical value. The developed method of assessing risk potential can be used not only for solving problems of this class to objects of railway transport but also for other chemically dangerous objects. By using the developed method was evaluated potential risk to the village Sinelnikovo in the event of accidental emission of ammonia.

48-54

Authors: O. V. Berlov

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.

62-70

Authors: V. M. Bubnov, I. Yu. Kebal, M. B. Mankevych

Purpose. The volume of cargo transportation demands the introduction of a new generation of cars that would be able to provide all the needs of carriers. But this is impossible without the implementation of renovation repair facilities with the introduction of new technologies and modernization of the repair process. Repair of rolling stock is a key factor that must proceed with the establishment of new cars, as not all of the inventions may be repaired in car-repair depots, most of which are obsolete. The purpose is to analyze the possibility of increasing the efficiency of the repair process by introducing new repair technologies or improving the existing ones. It will improve not only the quality of the repair, but also its rate. Methodology. Works on improving the designs of freight cars are held by many design organizations in almost all industrialized countries. It makes repair organizations (depots and car-repair plants) to upgrade the repair process. Achievements of-this goal is possible by improving the technology renovation and reorganization through the use of flexible flow technologies, which to date are the most effective in the repair of rolling stock. Findings. When performing the analysis it was determined that there are different designs of cars. More of cars are all-purpose and their repair does not cause difficulties for car-repair business. However, the number of specialized cars is also significant, and the technology of their repair should be improved. One of the reasons is that many models, such as tank wagons for the carriage of sulfur, are intended for the carriage of dangerous goods and their failure at the time of motion is not permitted. Originality. Firstly the authors have defined direction at improving technologies of repair specialized cars. Practical value. Actual improvement in the construction of cars is to improve the existing repair facilities. In addition, the repair technology using nowadays when repairing cars is obsolete and requires improvement. Considered organization of the repair process is of practical value and can be used both in-time development of new repair facilities and the modernization of existing ones.

85-99

Authors: G. I. Nesterenko, M. I. Muzykin, V. L. Horobets, S. I. Muzykina

Purpose. The paper is aimed to analyse the existing car traffic organization at the marshalling yard aimed to reduce downtime of cars. Methodology. The methods of mathematical statistics allowed building the histogram of car traffic flow distribution at the marshalling yard and assessment of their parameters. The key quantitative and qualitative indicators of the station operation were analyzed. In order to analyze the effect of rehandling volume on the rehandled transit car downtime elements at the station we plotted the dependence graph of the car downtime elements on the rehandling volume. The curve variation on the graph clearly shows the effect of rehandling volume on two downtime elements: during formation and in expectation of operations. Findings. The question of reducing the average downtime of all car categories at the station should be solved by reducing unproductive downtime was proved. The correct determination of the average time spent by a rehandled transit car at the station is essential, especially in the conditions of new system of economic incentives. But still there is no separate methodology for determining the car downtime, which would allow to objectively consider the equipment and operation technology and exclude the possibility for subjective decisions. Originality. One of the main kinds of unproductive downtime during the carriage of goods by rail is a downtime on the marshalling yards in expectation of technological operations because of the system congestion. Reduction of this indicator is possible due to rational use of the marshalling yard capacity provided the rational distribution and car – and train flows between the major marshalling yards of Ukrzaliznytsia. Practical value. The analysis of changes in downtime elements, depending on the rehandling volume allows not only to identify the car downtime reduction methods, but also to make a correct assessment of station staff work, as well as to adjust the rate of idle wagons.

109-121

Authors: V. I. Shynkarenko, H. V. Zabula

Purpose. Rapidly growing volumes of information systems data being manipulated significantly reduce the temporary algorithms effeciency of their processing . Effective data layout in RAM is one of the directions of solving this problem. It is necessary to develop the model to solve problems of efficient automated data layout in RAM. Methodology. For processes simulation of data structures (DS) adaptation in RAM, the methodology of mathematical and algorithmic constructivism was applied. This approach involves the development of constructive and productive structures (CPS) with transformations of specialization, interpretation, specification and implementation. CPS development provides definition of expandable vector, signature of relations, transactions and constructive axioms. The most complex and essential part of the set of axioms is generated substitution rules that determine the output process of respective structures. Findings. CPS system was developed by the authors, consisting of the logical structure constructor of data, converters of logical structure in to a software interface and implementation in a programming language, constructors of scenarios and adaptation processes. The result of the adaptation process constructor is software text generations of the class library that implements the specified logical data structure with appropriate processing operations and its compilation in binary code. Originality. Structural model of development processes and data structures adaptation to different software and hardware environments was first proposed. It adapts date layout in the RAM and data processing algorithms. Application of constructivism in simulation allowed within a single approach and applied tools linking the data models and algorithms of their processing with performance criteria. Formation methodology of CPS system, mechanisms, and links between complementary CPS were improved. Modification of the constructor and converters allows changing and exploring the process of adaptation. Practical value. The developed model allows automating the data layout in RAM, which in turn increases the time efficiency of programs with significant processing of large and very large volumes of data.

131-146

Authors: V. M. Bohomaz

Purpose. A drive is one of the basic elements of belt conveyers. To determine the drive power it is necessary to conduct calculations by standard methodologies expounded in modern technical literature. Such calculations demand a fair amount of time. The basic design parameters of a belt conveyer include type of load, design efficiency, geometrical dimensions and path configuration, operation conditions. The article aims to build the parametric dependence of belt conveyer drive power on its design parameters, that takes into account standard dimensions and parameters of belts, idlers and pulleys. Methodology. The work examines a belt conveyer with two areas: sloping and horizontal. Using the methodology for pulling calculation by means of belt conveyer encirclement, there are built parametric dependences of pull forces in the characteristic conveyer path points on the type of load, design efficiency, geometrical dimensions and path configuration, operation conditions. Findings. For the belt conveyers of the considered type there are built parametric dependences of drive power on type of load, design efficiency, geometrical dimensions and path configuration, operation conditions, taking into account the belt standard dimensions and corresponding assumptions in relation to idler and pulley types. Originality.This is the first developed parametric dependence of two-area (sloping and horizontal) belt conveyer drive power on type of load, design efficiency, geometrical dimensions and path configuration, operation conditions that takes into account standard dimensions and parameters of belts, idlers and pulleys. Practical value. Use of the built drive power dependences on design parameters for the belt conveyers with sloping and horizontal areas gives an opportunity of relatively rapid determination of drive power approximate value at the design stage. Also it allows quality selection of its basic elements at specific design characteristics and requirements. The offered dependences can be used for determination of general character of drive power dependence on the project efficiency.

158-168

Authors: V. V. Suglobov, S. V. Raksha, P. A. Hrynko

Purpose. In the study is necessary: 1) to justify aligning drums of a new design of belt conveyors; 2) to develop a method for calculating and determining the rational design parameters of drums depending on the technical parameters of the conveyor belt (the length of the conveyor, belt width, the performance of the conveyor, the diameter of the drive and tension drums, etc.); 3) to carry out pilot studies of efficiency conveyor belt in a production environment in order to determine the magnitude of dynamic loads and a comparative evaluation of the effectiveness of the centering ability of conventional and new designs of drums. Methodology. To substantiate the effectiveness of the centering ability of the drums of a new design by the authors developed a mathematical model of interaction of the tape with the drum. Mathematical simulation of tape reels with new design comes to drawing up a differential equation of the belt based on the dynamic component and restoring force. This model allowed us to estimate the movement of the tape in the transverse direction based on the calculated additional dynamic loads and forces on the investigated centering a conveyor belt with given specifications. For the first time the technique of calculating and determining the rational parameters of the drums, which allows determining the design parameters of the centering portions, depending on the mechanical properties and geometric parameters of the tape. Findings. With the help of mathematical modeling the scientifically substantiated effect of centering the ability of the new design of the drum, which ensures stable tape running along the longitudinal axis of the conveyor. The authors made the following conclusions: 1) the mathematical model of interaction with the new belt design of the drum, which allowed to describe the belt in the transverse direction in view of additional dynamic loads and renewable power was developed; 2) the method of calculation and determination of parameters of rational design of new barrels, which allows to determine the design parameters of centering areas was proposed ; 3) the experimental studies of conveyor belt with given technical parameters in a production environment, which allowed to determine the dynamic loads during the acceleration conveyor, as well as optimize the start time to reflect these pressures was conducted. Thus, stationary conveyors with increasing acceleration of time from 10-15 to 24 with dynamic loads can be reduced from the level of 20-35% to 9-10% of the nominal. Comparative evaluation of experimental and calculated values of the magnitude of dynamic loads makes the difference to 4%. Originality. For the first time offered the theoretical tools that justify the effective performance of a new design of the drums of belt conveyors, as well as allow us to determine their rational design parameters. Practical value. New designs of drums, their method of calculation and constructive parameters can be used in the design of new and modernization of existing belt conveyors that will minimize unplanned downtime and improve the durability of the belt.

180-192

Authors: A. O. Shvets, K. I. Zhelieznov, A. S. Akulov, O. M. Zabolotnyi, E. V. Chabaniuk

Purpose. In the analytical research are considered: 1) relationships between the longitudinal force acting on the car in the train; 2) lateral and vertical forces of interaction in the contact zone «wheel – rail»; 3) dynamic indicators of cars with the magnitude of the car lift resistance factor; 4) obtaining of the dependencies between them. Methodology. The study was conducted by an analytical method assessing the sustainability of the freight car when driving at different speeds on the straight and curved track sections. Findings. In the process of studying the motion of the train, in the investigation of transport events, as well as during the training on the simulator operator, to assess the actions of the driver, the values of the longitudinal forces in the inter car connections are used. To calculate the longitudinal compressive forces, acting on the car, in which car lift resistance factor will be equal to the allowable value (critical force). To assess the impact on the value of the longitudinal force speed, coefficients of the vertical and horizontal dynamics, as well as the wind load on the side surface of the car body are the results of calculations of motion of the empty gondola car, model № 12-532 curve radius of 250 m with a rise of 150 mm and a transverse run of body of car frame relative to the track axis of the guide section 50 mm. Originality. In this study, the technique of determining the longitudinal compressive force was shown, that is somewhat different from the standard. So, as well as assessing the impact on it the speed of rolling coefficients of vertical and horizontal dynamics and wind load on the side surface of the car body. Practical value. The authors developed proposals on the enhancement of existing methods for determining the value of the longitudinal compressive forces acting on the car in which the safety value of the car lift resistance factor will be equal to the allowable value. It will evaluate the stability of each train car lift resistance factor directly during the simulation of its movement. The most effective use of this technique in the simulator designed to teach the drivers a safe way of driving trains and in the investigation of the causes of cars derailment.