Trans Motauto World
Vol. 3 (2018), Issue 4

Table of Contents

  • TRANSPORT TECHNICS. INVESTIGATION OF ELEMENTS. RELIABILITY

    • DEVELOPMENT AND RESEARCH OF TEMPERATURE CONTROL SYSTEM OF A HIGH-VOLTAGE BATTERY OF A PERSPECTIVE ELECTRIC VEHICLE

      pg(s) 151-154

      The development of temperature control system of high-voltage batteries is an actual and important task in the development of modern electric and hybrid vehicles. There are a large number of designs and types of temperature control systems. In this article, we propose to consider a temperature control system based on a liquid cooling system and designed for both cooling and heating the battery in a wide range of ambient temperatures. In the development process of temperature control system for high-voltage batteries were carried calculations, 3D modelling of the design and tests.

    • VEHICLES FOR THE FUTURE – DILLEMAS AND PERSPECTIVES

      pg(s) 155-156

      The homeland of the first modern electrical car is Greece. Legendary Enfild 8000 is one of the first electrical cars in the world, and that small two-seater was also extremely economical. It originated from the Greek island of Syros, where it is exhibited today at the Industrial Museum in Hermoupolis.It is believed that electrical cars are the real small revolution, because we replaced one type of engine with the other, while the autonomous vehicles resistant to human errors will represent the first real big transport revolution of the 21st century. Experts believe that new models of cars will have the best test in Norway1, where during the last year drivers mostly (52%) voted for electric cars and hybrids. Electrified icons: Ford Mustang and Ford F-150 hybrids are coming by 2020. Porsche plans to sell 20,000 cars E mission per year. Also the French are planning to present 8 new electric cars (record holder is the model “zoe”2, and soon the EV version of the “Quid”, a small SUV that is sold on developing markets should join) before year 2022. In Serbia there is a plan to set up more charging stations for electrical vehicles. It will be initially only 3 stations within the project “Green Balkanica”, while it is cited that in China there are even 5 million of these stations.

    • THREE-DIMENSIONAL SIMULATION OF THERMAL STRESSES IN DISCS DURING AN AUTOMOTIVE BRAKING CYCLE

      pg(s) 158-161

      In this study, a 3-Dimensional finite element simulation of a braking cycle including braking and cooling steps is presented. In order to induce thermal stresses, thermo-mechanical material behaviour and interactions between pad and discs are considered in the simulation. The results reveal that compressive and tensile stresses are happening in the braking and cooling steps respectively. Cyclic tensile stresses in the disc of heavy trucks would lead to the initiation of superficial radial cracks in them. The occurrence of hot spot phenomenon in the discs are also observed and discussed thoroughly. The proposed model could be utilized to estimate fatigue life of the braking discs in the automobiles and heavy vehicles..

    • COMPARISON BETWEEN THE PURSUIT GUIDANCE AND THE PROPORTIONAL NAVIGATION GUIDANCE LAWS REGARDING A PREDETERMINED SCENARIO

      pg(s) 162-165

      In tactical missile design, it is highly crucial to select the proper guidance method in order to meet the scenario requirements. As it is applicable in every aspect of life, trade-off conditions should be measured meticulously to reach the most advantageous and economical outcome. In this study, a particular scenario with a manoeuvring target is taken into consideration. Two of the guidance laws, namely, the pursuit guidance and the proportional navigation guidance are then implemented and compared. Lastly, the effect of the missile acceleration is examined within the proportional navigation guidance to consolidate the study.

  • TRANSPORT. SAFETY AND ECOLOGY. LOGISTICS AND MANAGEMENT

    • IMPACT OF TECHNICAL VALIDITY MOTORCYCLE FOR ROAD SAFETY IN THE REPUBLIC OF CROATIA

      pg(s) 166-168

      The road traffic safety factor is divided into three basic groups: human, vehicle, road (infrastructure). Technically defective, poorly maintained and technologically obsolete vehicles endanger road safety. The number of technically defective vehicles that are involved in traffic accidents, when checks are carried out by officers of traffic police, is 0.2%. Considering that 21.31% of vehicles are found to be defective by periodical technical inspections of vehicles (PTI), it is expected that the number of technically defective vehicles in daily traffic is considerably higher. By analyzing the data collected by PTI and comparing them with the data obtained during the conducted research “Inspection of the technical safety of vehicles involved in road traffic accidents with fatalities” the real state of the technical condition and safety of vehicles on the roads in the Republic of Croatia is presented here. Two-wheel vehicles (mopeds and motorcycles) represent a particularly risky group.

    • APPLICATION OF GEOGRAPHICAL INFORMATION SYSTEMS TO EVALUATION A CONCENTRATION OF CHLORINE RELEASED INTO AN ATMOSPHERE IN THE CASE OF ROAD ACCIDENT

      pg(s) 169-172

      Modelling propagation of hazardous substances released in road accidents is important issue from the point of view of safety in road transport. The paper presents use of the Geographic Information Systems to analyse the impact of the emissions of hazardous compounds in the built-up area. In the paper dispersion of pollutants released in a road accident, involving a chlorine tanker truck, followed by chlorine spillage has been analysed. It is assumed that the accident took place in a mountainous area on a bypass within a built-up area. Concentrations of pollutant have been calculated in the own program. The calculation of field of wind speed was taking into account the terrain elevation and type of land cover. The package Idrisi Taiga has been applied in the pre-processing stage. It was used to generate a site map with buildings and aerodynamic roughness map. Meteorological conditions were also taken into account: wind speed and direction, temperature, atmospheric pressure and atmospheric stability class. The computer program consist two basic modules: diagnostic model of air velocity field and Lagrangian model of particles, being the original implementation of the Lagrange model of particles. In both models, some elements of mathematical modelling were applied. The models have been successfully validated and verified. The results of the calculations of concentrations of chlorine have been analysed in the Geographic Information System. The following analyses have been made, among others: designation of hazardous zones AEGL 1-3, determination spatial size of built-up areas within the zone, analysis of changes in pollution concentrations over time. The proposed analyses allows to determine areas exposed to deadly and highly dangerous concentration of chlorine.

    • EXPRESSION OF RISK THROUGH TARIFF POLICY IN RAIL PASSENGER TRANSPORT

      pg(s) 173-176

      Risk analysis is a process with a detailed identification of risks, determine their range and examines the interaction of these risks. Each process or human activity are influenced by many risks. As well as in rail transport there are many risks which hare accrue from the operation. Risk is defined as the chance that something will happen what will affect the goals and is measuring by results or estimate. We can also risk defined as the product of the likelihood of an adverse event (phenomenon) and consequences (outcomes). On one side is the risk connected with the hope of achieving a good financial results, but on the other side with the danger of business failure that brings losses. The aim of this paper is the proposal of a tariff taking into account the risk from unoccupied capacity of passenger trains. Pricing of selected risk we will eliminate this adverse event.

    • LINE TRACK CAPACITY – ANALYSIS OF THE IMPLEMENTATION OF THE UIC 406 METHODOLOGY IN ŽSR CONDITIONS

      pg(s) 181-184

      A variety of A variety of methodologies are used across Europe for the estimation of railway infrastructure capacity. This paper introduces the basic principles of the analytical methodology (e.g. Slovak railways) and UIC methodology. On the basis of these new approaches, dependencies between occupation time and buffer time is researched. The aim is to compare the needed buffer time and its impact to the line capacity.

    • VEHICLE PRODUCTIVITY IN NEW OPERATED RAIL-SERVICES

      pg(s) 185-187

      For newly introduced transport services, there´s not only the transport aspect that matters what the new service will bring to passengers, but also the operating costs are very important. In this area the systematic timetable planning plays an important role. Total costs of the transport system are significantly affected by the fixed costs, deriving from the number of regular deployed vehicles and drivers, related to the overall transport performance and total operational productivity. Advanced timetable engineering means a strong link between timetables, vehicles and infrastructure. The article demonstrates this approach on the example of the introduction of new express trains Praha – Plzeň – Cheb / München in the timetable 2017/18.

  • VEHICLE ENGINES. APPLICATION OF FUELS TYPES. EFFICIENCY

    • EFFECTS OF PROPELLANT PROPERTIES ON INTERNAL BALLISTIC PERFORMANCE RESULTS OF SOLID ROCKET MOTORS

      pg(s) 188-191

      The aim of this research is to examine the effects of propellant properties such as: combustion temperature, propellant density, characteristic velocity, reference burning rate and burning rate pressure exponent on internal ballistic performance of solid rocket motors. A zero dimensional internal ballistic solver is developed and internal ballistic performance analyses of solid rocket motors having slotted cross section are performed. Thus, different internal ballistic results such as maximum combustion pressure, burning time, specific impulse and total impulse are determined. Finally, variation of these response variables according to solid propellant properties are determined constructing different response surfaces. Graphical results represented in this work makes easier to select solid propellants for a certain kind of geometrical configuration.

    • IMPROVEMENT OF WHEELED TRACTOR’S REGULATOR IN DIESEL ENGINE

      pg(s) 192-194

      On wheeled tractors it is expedient to erect the universal regulators, which can be set on singlemode regulation or multimode one, on the basic of serial multimode regulator 4 UTNM the key diagram, construction and manufacture design of research sample of universal multimode – singlemode regulator were worked out.
      The work is directed at raising of fuel economy and lowering of harmful rejections of wheeled tractor when performing transport work by using universal regulator and optimal partial high-speed characteristics under one-mode regulation. Worked out mathematical model of the system “operator-tractor train-road” for investigating of influence of character of proceeding of partial high-speed characteristics of diesel engine on expenditure of fuel and harmful rejections of wheeled tractor.
      Investigations, conducted on this model, showed the advantages of one-mode regulation in the cases of work of diesel engine at variable modes. Inclination of partial high-speed characteristics under one-mode regulation essentially didn’t influence on economical and ecological indices of wheeled tractor. By experimental investigations is confirmed the adequacy of mathematical model and checked the efficiency of experimental universal regulator.

    • EFFECT OF FUEL ADDITIVES ON DIESEL ENGINE PERFORMANCE AND EXHAUST EMISSIONS

      pg(s) 195-203

      The performance and combustion emissions of diesel engine can be modified using various chemical fuel additives. Fuel additives consist of a variety of chemical compounds. It contains chemical elements such as: hydrocarbons, C11-C14, C10-C13, n-alkanes, isoalkanes, cyclics aromatics, cycloalkane, 2-ethylhexyl nitrates. Analysis has been conducted on diesel fuel and diesel fuel and additives blends. Fuel additives No.1, No.2 and No.3 consisting of these chemical elements have been analysed. The obtained results show, that the amounts of carbon monoxide emissions at low engine loads (IMEP = 0.32 MPa) increases up to 35% compared to pure diesel fuel. While using additives, the hydrocarbons emissions at low engine loads almost doubles compared to pure diesel fuel. The break specific fuel consumption with the engine powered by pure diesel fuel was lowest in all modes. The highest increase on in cylinder pressure 11% was only determined with the fuel additive No.3 at the maximum load of 1.12 MPa at the speed of 1800 rpm.