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Browsing Статті КЛ by Author "Bobyr, Dmytro V."
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Item Defining the Limits of Application and the Values of Integration Variables for the Equations of Train Movement(National Technical University «Dnipro Polytechnic», 2019) Bodnar, Borys Ye.; Kapitsa, Mykhailo I.; Bobyr, Dmytro V.; Kyslyi, Dmytro M.ENG: Railway transportation is an integral part in the transport infrastructure of our country. They cover passenger and cargo transportations by Ukrzaliznytsia, industrial enterprises, including transportation of the mining sector, which is characterized by heavy loads on the traction rolling stock due to large gradients of the track profile. Railway transport management is always preceded by traction calculations, the center of which is to solve the equation of train movement.Purpose.To determine the rational values of the variables in solving the equation of train movement, as well as relevant limits in their applicability.Methodology. To achieve the purpose, methods of system analysis, nonlinear programming, numerical methods for solving differential equations, namely the classical, Runge-Kutta-Feelberg, and Rosenbrock methods, are used. Computational accuracy was verified using simulation methods and compared with experimental data. Findings. The results of the research involve increasing the calculating speed when solving the equation of train movement without loss of accuracy, which allowed using the proposed method in on-board systems of locomotives. Originality. During the research, new scientifically grounded results were obtained that solve the scientific task in improving the energy efficiency of train operation, and are of great importance for railway transport. The obtained results constitute the originality, which consists in determining the rational limits of applicability and the value in a step of integration variables for the equations of the train movement. Practical value. The research results allow reducing the cost of energy consumed by hauling operations due to the promt recalculation of rational control modes when changing the train situation.Item Determining Permissible Speed of Tilting Train in Curved Track(Дніпровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпро, 2017) Kapitsa, Mykhaylo I.; Bobyr, Dmytro V.; Desiak, Andrii Y.ENG: Purpose. The main purpose of the article is to determine the permissible speed of the air-cushioned tilting train in curved track and to justify the expediency of operating this type of rolling stock on the railways of Ukraine to increase the speed, improve the passenger comfort and save the energy due to more uniform high-speed train driving. Methodology. The determination of the maximum permissible speed of the tilted train in curved track involves the use of methods of linear and vector algebra and empirical formulas for applied scientific and technical research. The calculation of the maximum speed is based on the principle of calculating centrifugal force for the velocities that meet the safety criteria of movement on the horizontal unbalanced acceleration in the stable radius curve. Findings. The results of the calculations showed that in the 1000 m radius curved track section, provided the passenger comfort, the maximum permissible speed of the train without forced tilt is 132 km/h, and with the forced tilt – 189 km/h. The velocity gain in the curve is about 30% and up to 10% on the section (depending on the number of curves). Originality. The method of determining the permissible speed of the tilted train in curved track is improved, which consists in determining the permissible centrifugal force acting on the train in the stable radius curve, taking into account the passenger comfort conditions. Practical value. This method allows accurately determining the permissible speed on the condition of passenger comfort in the curved section and the required additional tilt angle of the train, depending on the speed, curve radius and canting. Enhanced speed and comfort of passenger trains in the future will increase the demand for rail services among the population and strengthen the position of rail transport in Ukraine’s transport system.Item Efficiency of Modernization of Wheel-Motor Blocks using Anti-Friction Traction Motor Support Bearings(Дніпропетровський національний університет залізничного транспорту ім. акад. В. Лазаряна, Дніпро, 2018) Kapitsa, Mykhaylo I.; Gnennyi, O. M.; Bobyr, Dmytro V.ENG: Purpose. The use of anti-friction traction motor support bearings (TMSB) instead of plain friction traction motor support bearings is a priority direction of locomotive development both for newly constructed locomotives and for those in operation. The solution of the set tasks for introduction of wheel-motor blocks (WMB) with anti-friction bearings demanded the search for alternative variants and new technical solutions. The purpose of the article is to determine the feasibility of re-equipping the diesel locomotive wheel-motor blocks with anti-friction bearings through the life cycle calculation (LCC). Methodology. The procedure and criteria for assessing the economic efficiency of project (investment) proposals and investment projects approved by the Cabinet of Ministers of Ukraine envisage that the cost-effectiveness analysis of an investment project is carried out according to the following criteria: net present value, internal rate of return, discounted payback period and profitability index. The use of these criteria of economic efficiency fully corresponds to modern principles, theoretical-methodical approaches and world practice in evaluating the efficiency of investments. The evaluation of the technical and economic efficiency of the modernization of the diesel locomotive wheel-motor block is made on the basis of calculation and comparison of the following criteria: the net present value (NPV) of modernization, the internal rate of return (IRR), the profitability index (PI) and the discount payback period. Findings. The results of the calculations of the values of the main criteria show that the innovative project for the modernization of the locomotive provides a high level of economic efficiency. At the same time, the value of the discounted payback period of investments in modernization indicates that it is expedient to carry out this operation if the residual life of the upgraded locomotive of the M62 series is at least 15 months. Originality. Taking into account the specifics of the type of locomotive work in freight traffic, we developed a method to determine the individual components of the average annual economic effect of modernization of the diesel locomotive wheel-motor block, which includes saving of oil costs, repairing and servicing the diesel locomotive wheel-motor unit, as well as change of TMSB brass and saving fuel costs for traction. Practical value. The results of the work make it possible to determine the expediency of modernization of diesel locomotives taking into account the features and conditions of their operation and the specifics of modernization.Item Improving Operation and Maintenance of Locomotives of Ukrainian Railways(Vilnius College of Technologies and Design, Vilnius, Lithuania, 2016) Bodnar, Borys Ye.; Ochkasov, Oleksandr B.; Bobyr, Dmytro V.ENG: The results of research according to operation system improvement and locomotive technical equipment of Ukrainian railways are represented in the article. The scientific work is carried out by “Technical maintenance and diagnostics of locomotives” laboratory of Dnipropetrovsk National University of Railway Transport named after acad. V. Lazaryan. The methods and hardware and software system of train handling rational modes selection are developed for exploitation system improvement. The theoretical basis of implementation necessity of technical diagnostics equipment in locomotive unit is outlined in the article. The method for determining the limits of diagnostic parameters change is suggested. The method can be used in the preliminary stage of locomotives maintenance development system, the locomotives are equipped with on-board diagnostics systems. The examples of diagnostic systems for locomotives node points and their work results are enumerated.Item Research of Mathematical Model of Movement of Six-Axle Locomotives with Controllable Wheelsets Installation(Springer, Cham, 2020) Kliuiev, Serhii; Bobyr, Dmytro V.; Vaičiūnas, Gediminas; Steišūnas, StasysENG: Research of mathematical model of movement of six-axial locomotive with controllable wheelsets installation. Based on the general system of nonlinear variable coefficient differential equations of the vehicle movement in a rail track with inequalities in plan, the mathematical model of movement dynamics of locomotive of improved design with the axial formula 30-30 as an object of automatic control of the wheelsets position in the rail track is considered. Movement simulation is performed on the example of a six-axle locomotive at the speeds of movement and parameters of the curvilinear track sections, which coincide with the conditions of the experiment presented in the thesis work of V. N. Yazykov. The article presents research results of the mathematical model of movement of the improved locomotive bogie with controllable wheelsets installation in the curvilinear track sections using the Matlab/Simulink software package. The results of experimental studies of the All-Russian Scientific-Research and Design Technological Institute of Rolling Stock and the performed theoretical studies show that the efficiency of the improved system for controlling the wheelset position is higher than that of the serial design, in all modes of movement. The improved system of automatic control of wheelsets position makes it possible to reduce guiding forces by 35%. The possibility of using the mathematical model of locomotive movement of the axial formula 30-30 of improved bogie design with axle-box links of adjustable length, taking into account the dynamics of the automatic control system of the wheelsets installation in the rail track, is theoretically substantiated. The theoretical research found out the reduction of lateral forces in the improved bogie design during the passage of curvilinear track sections. The use of the explored mathematical model of locomotive movement reduces the volume and complexity of research works, as well as increases the reliability of engineering calculations when designing new and improving existing designs of the locomotive underframe.Item Using the Self-Braking Method when the Post-Overhaul Diagnostics of Diesel-Hydraulic Locomotives(Kaunas University of Technology; Publishing House “Technologija“, Kaunas, Lithuania, 2018) Bodnar, Borys Ye.; Ochkasov, Oleksandr B.; Bobyr, Dmytro V.; Koreniuk, Roman O.; Bazaras, Ž.ENG: A large number of diesel-hydraulic locomotives are operated at industrial enterprises. Reliability of diesel locomotives in operation directly depends on the quality of the conducted acceptance testing of the hydro-transmission after repair. Test procedures presuppose running-in and testing the hydraulic transmission in all modes of its operation. Run-in time is established by normative and technical documentation. During the running-in, the technical condition of the hydraulic transmission is determined on the base of the control of input and output parameters (shafts speed, temperature and oil pressure). The authors propose to improve the running-in process by introduction of tools and techniques of technical diagnostics. With this aim features of post-overhaul diagnostics of diesel-hydraulic locomotive were analyzed. The article deals with the diagnostics the condition of the mechanical part of the hydraulic transmission UGP (UHT- unified hydraulic transmission) 750/120 after a major overhaul. Choosing the diagnostic parameters of the mechanical part of the hydraulic transmission was carried out. We proposed to use free path (self-braking) mode to determine the mechanical losses at bench tests. As the criteria, determining the technical state of the mechanical part of the diesel-hydraulic locomotive during the tests in the self-braking mode, the following values are proposed: run-down time of shafts; change in the braking torque and the power of mechanical losses depending on the angular velocity. Diagnostics of the hydraulic transmission according to the above criteria allows reducing the time of receive/running-in tests and significantly increasing the technical condition accuracy and characteristics of the technical condition.