Science and Transport Progress. Bulletin of Dnipropetrovsk National University of Railway Transport 

About: Science and Transport Progress. Bulletin of Dnipropetrovsk National University of Railway Transport is an academic journal published by Dnipropetrovsk National University of Railway Transport named after academician V. Lazaryan. The journal publishes majorly in the area(s): Track (rail transport) & Train. It has an ISSN identifier of 2307-6666. It is also open access. Over the lifetime, 874 publications have been published receiving 1544 citations. The journal is also known as: Science and transport progress & Nauka ta progres transportu. Vìsnik Dnìpropetrovsʹkogo nacìonalʹnogo unìversitetu zalìzničnogo transportu ìmenì akademìka V. Lazarâna.

Atmosphere protection in case of emergency during transportation of dangerous cargo

Abstract: Purpose. The paper highlights the d evelopment 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.

Features of perception of loading elements of the railway track at high speeds of the movement

Abstract: Purpose . Increase the train speeds movements requires not only the appropriate technical solutions, but also methodological-calculated. Most of the models and methodologies used for solving problems of stress-strain state of the railroad tracks, are based on assumptions and hypotheses adequate only for certain speeds. In the framework of this work will be discussed theoretical background of the changing nature of perceptual load elements of the railway track at high speeds and investigated the numeric parameters of the processes by means of mathematical modeling. As a practical purposes is expected to provide the levels of train speed, the boundaries of which can reasonably exclude the possibility of occurrence of the considered effects. Methodology . To achieve these objectives was used principal new model of railway track based on wave propagation theory stresses in the elastic system to study the impact of the movable load, take into account that the deflection in a particular section of the road starts even while the wheels at some distance, and moving the wheels farther from the selected section of the wave front elastic strain continues to spread. According to the results of simulations explores the changing shape of the wave front voltages in time for the foundation under the rail. If the train speeds substantially less than the velocity propagation of elastic waves, the wheel remains in the area implemented deformations. Findings . Alternative calculations for various parameters of the railway track (especially for different soil conditions) determined the levels of train speed, the boundaries of which can reasonably exclude the possibility of occurrence of the considered effects. Originality . The proposed theoretical study and implementation in the form of mathematical models for processes that occur in the perception of load elements of the railway track at high speeds. Practical value. According to simulation results obtained levels of speeds, which define the appearance of the considered dynamic effects in the base under the rail, can be used to justify path construction or establishment of appropriate values of allowable velocities for the implementation of traffic at high speeds.

Reforming and Restructuring Ukrzaliznytsia: A Crucial Task for Ukrainian Reformers

Abstract: Purpose. This article examines options available for Ukraine as the country considers proposals to reform and restructure Ukrzaliznytsia. Methodology. The basic restructuring options observed internationally are presented, and the literature concerning their impacts and effectiveness is reviewed. Findings. The creation of competition among freight train companies has been found to improve system performance, but the EU policy prescription of complete vertical separation may not be required in order to achieve this. The Americas-style policy of horizontal separation has also been found to improve system performance, and may be more appropriate for a country as large as Ukraine and a railway as dependent on freight operations as Ukrzaliznytsia. Originality. Most of the literature on railways restructuring focuses on vertical separation or third party access, while the focus here is on a policy option arguably more appropriate to Ukraine. Practical value. Ukraine’s economy is dependent on the efficient shipment of bulk commodities such as coal, iron ore, steel, and grains – commodities that travel most economically over long distances by rail. The successful reform and restructuring of Ukrzaliznytsia will be a crucial part of Ukrainian economic reforms going forward.

Study of dynamic indicators of flat wagon with load centre shift

Abstract: Purpose . The article deals with the determining the influence of the longitudinal and lateral shift of gravity centre of the heavy load on the flat wagons, taking into account the travel speed based on the main dynamic indicators – the maximum coefficients of the dynamic supplement of spring-suspended and unsprung parts, the maximum ratio of frame force to static axle load, the wheel derailment safety factor. Methodology . The study was carried out using the method of mathematical and computer simulation of the dynamic loading of flat wagons based on the model of spatial oscillations of five coupled wagons and the software complex developed in the branch research laboratory of the rolling stock dynamics and strength (BRL RSDS). Theoretical studies were carried out during the movement of the model 13-401 flat wagon on typical 18-100 bogies with speeds in the range from 50 to 90 km/h in curves with radii of 350 and 600 m, with 130 and 120 mm canting, respectively. Findings . The paper presents the analysis of theoretical studies of the rolling stock dynamics on the example of flat wagons. The calculations were carried out using an application software package. In the course of performing theoretical studies and after simulation, taking into account the processes of oscillation of the flat wagon and load in the presence of longitudinal and lateral shift of its gravity centre, the dependences of the main dynamic indicators were obtained with regard to the magnitude of the travel speed. Originality . Using the mathematical model of the five coupled wagons, the effect of shift in two directions from the central symmetry axis of the heavy load centre was studied with regard to the travel speed along the curved track of small and medium radius in order to determine the dynamic loading of the flat wagon. Practical value . As a result of the above theoretical studies, the recommendations on the maximum possible values of the centre shift of heavy loads during their transportation on flat wagons are substantiated and proposed.

Choosing the system of locomotive maintenance in view of the effect of dependent failures

Abstract: Purpose. Improving the efficiency of the use of locomotives by choosing a rational maintenance system that takes into account the assessment of the effect of dependent failures on the cost of their life cycle is the main purpose of this paper. Methodology. The relevance of introducing LCC (Life Cycle Cost) approaches in locomotive facilities is explained by the introduction of new locomotives with on-board control and diagnostic systems, as well as the development of the theory of traction rolling stock maintenance systems. The cost of a locomotive as a traction unit ceases to be the determining factor. This is because the locomotive maintenance and repair cost for the entire period of its operation is much higher than the initial cost of the locomotive. The paper analyses the existing approaches to managing the cost of the life cycle of locomotives at the stages of selecting, updating, upgrading and operating the traction rolling stock. The necessity of improving the methods for assessing the degree of influence of reliability indicators of locomotive assemblies on the choice of the maintenance system and the cost of the locomotive life cycle is substantiated. Findings . It is proposed to use the concept of «the effect of dependent failures» when calculating the cost of locomotive renewal after unscheduled repairs and its life cycle cost. We improved the methods for determining the cost of unscheduled repairs, taking into account dependent failures and the coefficient of assessment of the effect of dependent node failure on the locomotive maintenance system. The proposed coefficient will determine the nodes, the failure of which affects the renewal cost more than their nominal value. It will also help to take into account the probable losses due to node failure during the development and adjustment of the locomotive maintenance system. Originality . For the first time, it is proposed to use the concept of the effect of dependent failures to calculate the locomotive renewal cost when performing unscheduled repairs, as well as the locomotive life cycle cost. Practical value. The improved calculation method for determining the cost of unplanned repairs with account taken of dependent failures can be used to compare and evaluate different variants of the locomotive maintenance system and to develop the locomotive diagnostic systems.