Кафедра Управління перевезеннями і технологічними процесами залізниць <br>(Раніше Кафедра "Транспортні технологіі")

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ENG: Department of Railway Transport and Technological Management
(Formerly Department of Transport Technologies)

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Improvement of the Method for Standardizing the Duration of Rail Cars Shunting
(НГУ, Дніпро, 2021) Kozachenko, Dmytro M.; Gera, Bogdan V.; Manafov, E. K.; Gorbova, Aleksandra V.; Korobiova, Ruslana G.
ENG: Purpose. To improve the method for calculating the time standard for shunting cars from track to track in order to take into account the local operating conditions of railway stations and railway sidings. Methodology. During the research, the methods of theory of railway operation were used. The problem of calculating the time standard for shunting operation was solved as the problem of searching the optimal division of train set into the car groups to achieve minimal time consumption for shunting operation. Findings. In the course of the study, the methods for calculating the time standards for initial and fi nal operations, as well as movements performed when shunting cars from track to track were improved. It was proved that the minimum time spent on shunting cars from track to track was achieved when the train set was divided into the minimum possible number of parts and the cars were shunted in the longest possible groups and one remaining group. It was also established that with suffi cient accuracy for engineering problems the duration of shunting train set from track to track can be represented by the piecewise linear function of the car number in it. Originality. The work originality consists in improving the method for calculating the time standard for shunting cars from track to track, that, unlike the existing one, takes into account the length limitations of the car groups being shunted from track to track, as well as the actual composition of operations performed in the process of shunting. Practical value. The use of the developed method allows setting time standards for shunting cars from track to track, taking into account the local operating conditions of railway stations and sidings of industrial enterprises. The method also makes it possible to simplify solving problems of searching the optimal order of performing more complex shunting operations, such as sorting cars into several tracks, collecting cars on one track, train formation, and others.
Longitudinal Vibrations of Viscoelastic Longitudinally Nonuniform Rod under Power Load Distributed Along its Length
(Lviv Polytechnic National University, Lviv, 2016) Gera, Bogdan V.; Sitarz, Marek; Bolzhelarskyi, Yaroslav V.
EN: In this article, the dynamic behavior of a moving elongated object is simulated using the relations for a viscoelastic rod, which moves at a constant speed under the action of traction force and distributed along its length external forces of resistance. We investigate the change of displacements and internal forces after the sudden application in the rod section of the local force directed longitudinally. The correlations of the initial boundary value problem that describes the dynamic behavior of the rod are written down, and its solution is obtained in the form of a series expansion in terms of eigenfunctions. For a viscoelastic rod consisting of three connected uniform rods, the analysis of wave processes induced by the application to the rod of a sudden concentrated force that resists the motion is carried out. This affects the motion of the rod as a whole, and induces the wave processes, the propagation and reflection of waves on the inner surfaces of joints. The comparison is performed for the behavior of an elastic, piecewise nonuniform rod and a viscoelastic rod with different mechanical characteristics, where the waves during their propagation are damped and smoothed.
A Model of Transit Freight Distribution on a Railway Network
(The Silesian University of Technology, Katowice, Poland, 2019) Kozachenko, Dmytro M.; Skalozub, Vladyslav V.; Gera, Bogdan V.; Hermaniuk, Yuliia M.; Korobiova, Ruslana G.; Gorbova, Aleksandra V.
ENG: Summary. The peculiarity of the transit freight transportation by rail in international traffic is the fact that while performing transportation, the railway administrations are in competition among themselves. At the same time, the routes of cargo traffic volumes sig- nificantly depend on the conditions of transportation by railways of individual states. The mathematical model for the distribution of transit freight traffic volumes on the railway network, based on the methods of graph theory and game theory, was proposed in this ar- ticle. The developed model enables the evaluation of the possibilities of attracting transit freight traffic volumes by indi by changing the tariff value and transportation conditions.
Obtaining and Investigation of the Conditions of Heat Transfer Through Inhomogeneous Inclusion with Heat Sources
(Національний університет «Львівська політехніка», Львів, 2015) Gera, Bogdan V.; Dmytruk, Veronika A.
EN: The conditions of nonideal heat transfer are obtained for a heat conduction problem of contacting layers through a thin heterogeneous sublayer (inclusion) with acting heat sources (heat sinks). These conditions include both thermal resistances of components of the inclusion and specific powers of heat sources in them. On this basis, the heat conduction problem with nonideal conditions of heat transfer without consideration of inner inclusion is written down. Their use ensures observable features of temperature and heat flux, i.e. the function of temperature and the function of heat flux have a drop when passing through the contact interface. The magnitude of thermal resistance is suggested to be determined by means of more usual for measuring values, e.g. a thermal conductivity coefficient and a thickness of the inclusion. Surface specific heat sources can be set if the values of heat dissipation on the contact boundary are known. From the obtained and generalized heat transfer conditions, the known conditions of nonideal thermal contact can be obtained as particular cases.