Šarūnas Mikaliūnas

Research on the compatibility of the calculation methods of rolling‐stock brakes

Abstract One of the main tasks approached by the European Union is the liberalisation of railway transport service market. The foremost problem solved in this paper is the interoperability of various railway systems in the countries of the European Union. Thus, the immediate goal is to solve the problem of the interoperability of different railway systems used in the European Union. A distinction between railway track gauges (from 1435 to 1668 mm), particular couples of wagons, various clearances of rolling stock, different systems of infrastructure etc. are the main impediments. One of the problems in the nearest future will be the evaluation of the brakes of different wagons produced in Western Europe and the former Soviet Union. Freight trains in Lithuania consist of these two types of wagons, and therefore some problems of correcting the results of calculating braking distances and brake force may arise. The main object of this research is to investigate the methods evaluating the brakes of rolling‐st...

Determining Major Factors Causing the Wear of Wheelset Tyres

Graphical representation of laws governing the abrasion of locomotive wheelsets shows different distribution of values obtained for oiled and not oiled wheelset tyres. When wheelset tyres are oiled, the much higher deviation of abrasion values can be observed. This allows us to assume that oiling is more important for reducing the wear of not heavily loaded wheelset tyres.

Analysis of locomotive wheel sets wearing

Abstract Wearing dynamics of traction rolling-stock wheel tyres of diesel locomotives was investigated. Based on research results it is possible to predict wheel-tyre safety margin, to improve maintenance and state periodicity of repair, as well as to use traction rolling-stock repair funds most efficiently.

Methods for numerical calculation of parameters pertaining to the microscopic following-the-leader model of traffic flow: using the fast spline transformation

As known in transport engineering, civil engineering, transport planning and mathematics, traffic flow is the study of interactions between vehicles, drivers and infrastructure (including highways, signage and traffic control devices), with the aim of understanding and developing an optimal road network with efficient movement of traffic and minimal traffic congestion problems. The presented paper discusses a small part of a traffic flow study – the development of the methodology for assessing the speed and acceleration of a car during the column movement followingthe-leader, based on a new mathematical method. Two methods – (1) the numerical calculation of the first derivative, i.e. speed of the car movement; (2) the numerical calculation of the second derivative, i.e. acceleration of the car movement – were developed, using the fast spline transformation. In the future, parameters obtained with the help of two new methods, can be used to solve complex transportation problems, such as: (1) control of tra...

INVESTIGATION OF COMBUSTION, PERFORMANCE AND EMISSION CHARACTERISTICS OF SPARK IGNITION ENGINE FUELLED WITH BUTHANOL – GASOLINE MIXTURE AND A HYDROGEN ENRICHED AIR

In this study, spark ignition engine fuelled with buthanol-gasoline mixture and a hydrogen-enriched air was investigated. Engine performance, emissions and combustion characteristics were investigated with different buthanol (10% and 20% by volume) gasoline mixtures and additionally supplied oxygen and hydrogen (HHO) gas mixture (3.6 l/min) in the sucked air. Hydrogen, which is in the HHO gas, improves gasoline and gasoline-buthanol mixture combustion, increases indicated pressure during combustion phase and decreases effective specific fuel consumption. Buthanol addition decreases the rate of heat release, the combustion temperature and pressure are lower which have an influence on lower nitrous oxide (NOx) emission in exhaust gases. Buthanol lowers hydrocarbon (HC) formation, but it increases carbon monoxide (CO) concentration and fuel consumption. Combustion process analysis was carried out using AVL BOOST software. Experimental research and combustion process numerical simulation showed that using balanced buthanol and hydrogen addition, optimal efficient and ecological parameters could be achieved when engine is working with optimal spark timing, as it would work on gasoline fuel.