Communications - Scientific Letters of the University of Zilina, 2005 (vol. 7), issue 1
Articles
Wheelset/Rail Geometric Characteristics Assessment with Regard to Wheelset Rolling
Juraj Gerlici, Tomas Lack
Communications - Scientific Letters of the University of Zilina 2005, 7(1):5-10 | DOI: 10.26552/com.C.2005.1.5-10 
The geometric relation between a wheelset and a rail is assessed with the help of geometric characteristics. Geometric characteristics are: equivalent conicity function, delta r function placement of contact points of a wheelset and a rail, tangent gamma function and effective conicity.It turned out that these characteristics are at present the most important not only for the judgment of ride characteristics of a vehicle on the rail but also for the wearing of wheel treads and rail heads, e. i., for the assessment of the track and vehicles in order to find out the current state and for the assessment of changes of the wheels and rails profile shapes...
An Analysis of Heat Flows in the Combustion Engine of a Ship Non-Conventional Energetic System
Vladimir Hlavna, Dusan Sojcak
Communications - Scientific Letters of the University of Zilina 2005, 7(1):11-15 | DOI: 10.26552/com.C.2005.1.11-15
The paper describes a possibility of implementation of a non-conventional energetic system for ships. The described system is a source of heat at three levels, cool, refined electric energy and mechanical energy. Individual secondary energies are acquired by means of transformation of primary chemically bound energy in fuel. Primary energy is transformed by means of a combustion engine used as a driving unit of ships designed for transportation of passengers and goods. Mechanical energy can be used to drive a ship and its equipment. Exergy as a source of heat and cool for technological equipment of a ship. The implementation of a non-conventional system...
An Analysis of Vehicle Vibration with Uncertain System Parameters
Milan Saga, Milan Letrich, Roman Kocur
Communications - Scientific Letters of the University of Zilina 2005, 7(1):16-21 | DOI: 10.26552/com.C.2005.1.16-21
The study proposes an application of fuzzy arithmetic for analysis of randomly excited structures with uncertain or inexact system parameters. The purpose of the paper is to investigate possibilities of a fuzzy technique in a vehicle dynamic analysis. The solution of the problem will be realised in MATLAB using the program CAR_FUZ.M with a special module INTLAB.
The Influence of Liquid Load Motion on Rollover Stability of Road Tankers
Miroslav Tesar
Communications - Scientific Letters of the University of Zilina 2005, 7(1):22-25 | DOI: 10.26552/com.C.2005.1.22-25
Rollover threshold is an essential factor in research into road tanker behavior since the accidents involving these vehicles frequently have fatal consequences, especially when their load is of a flammable or toxic nature.The following article presents a method of identifying the influence of liquid motion in a partially filled road tanker. The method is based on simulation using a mathematical model developed with the help of MSA (Multi-body System Analysis) software. This software enables the user to evaluate all the factors that influence rollover stability. Mechanical pendulum methodology has been used to simulate the liquid motion.The road tanker...
The Method of Determination of Heat Emission Characteristics in Piston Self-Ignition Internal Combustion Engine
Andrzej Ambrozik
Communications - Scientific Letters of the University of Zilina 2005, 7(1):26-30 | DOI: 10.26552/com.C.2005.1.26-30
The article presents the method of plotting real indicator diagrams for piston internal combustion engines. Owing to the analysis of the diagrams, it is possible to determine the self-ignition delay period and also the characteristics of the relative amount of heat emitted in combustion process. The methodology worked out by the author accounts for changes in the amount and thermodynamic properties of the working medium present in the cylinder.
Visualisation Research into Fuel Spray Propagation
Hubert Kuszewski, Kazimierz Lejda, Zygmunt Szlachta
Communications - Scientific Letters of the University of Zilina 2005, 7(1):31-35 | DOI: 10.26552/com.C.2005.1.31-35
The results of research into a new construction of a diesel engine multi-hole injector are presented. The injector needle (RSN injector) performs a rotary/swinging movement. During the fuel injection the needle changes the area of atomizing orifices. This design changes the shape of atomized fuel sprays and has impact on their properties. The range of the spray front, the top angle of the spray and the area of the spray projection in a plane perpendicular to the injector axis were analyzed.
Frictional Behaviour of Thin Tin Films with a Copper Interlayer
Martin Komlossy, Marian Dzimko, Yoshinori Takeichi, Masao Uemura
Communications - Scientific Letters of the University of Zilina 2005, 7(1):36-40 | DOI: 10.26552/com.C.2005.1.36-40
Generally, the purpose of the study is to know the effect of temperature during tin-films deposition on frictional behaviour and lifetime of a tin layer with copper interlayer. In a recent study an experimental approach was performed to investigate the effect of a copper interlayer thickness on frictional behaviour of thin films. In this experiment, copper of 2 m thickness was deposited between the steel substrate and tin films of 1 m and 2 m thicknesses in vacuum environment without and with the heating of the substrate up to 300 °C. The friction tests were performed to determine the friction coefficient and lifetime of lubrication capability.
The Development of Robot Control, Robot Simulation and Digital Image Processing
Viera Poppeova, Juraj Uricek, Robert Zahoransky, Tibor Galbavy, Klaus Muller, Swen Schmeisser
Communications - Scientific Letters of the University of Zilina 2005, 7(1):41-46 | DOI: 10.26552/com.C.2005.1.41-46
The automation of manufacturing processes finds its application almost in all spheres of the economy of all industrial developed countries. Its inseparable part is represented by robotisation of manufacturing technologies in production. Nowadays robots and manipulators are quite common building element of automated workplaces, where they safeguard namely manipulation, control and measurement operations, operation and manipulation transport, exchange of tools, removing scraps in production. They are the only real tools for performing operations in dangerous or harmful environment for people (welding, spraying of colour or anticorrosive paint, work with...
Application of a Transportation Flux for Determining Qualitative Indices
Aleksander Nieoczym
Communications - Scientific Letters of the University of Zilina 2005, 7(1):47-48 | DOI: 10.26552/com.C.2005.1.47-48
A method of using the transportation flux of a manufacturing system for determining its qualitative parameters has been presented. Those subjects were discussed in many papers [1 - 4], however the presented method may be used for a preliminary determination of functionality of manufacturing system parameters when, as a consequence of its modernization a change in equipment of a certain section or a replacement of individual devices was planned. Such actions cause a necessity to determine the system's operating efficiency and reliability after changing parameters as well as the impact of working processes on the product quality. Such actions were conducted...
Differential Hydro-Mechanical Transmissions with Hydrostatic Units
Frantisek Brumercik, Roman Kocur, Milan Pazican, Michal Lukac
Communications - Scientific Letters of the University of Zilina 2005, 7(1):49-53 | DOI: 10.26552/com.C.2005.1.49-53
At present, hydromechanical transmissions are used especially in agricultural and defence vehicles. These transmissions have potential to be used also in other vehicles, for example commercial cars and buses. Differential hydromechanical transmission generation needs to achieve comparable parameters in comparison with the competition to prove maximum of drive comfort, safety, reliability and efficiency.