Journal of Mechanical and Transport Engineering

CONSTRUCTION CHANGES FOR VEHICLE ENGINES POWERED WITH LPG MADE TO EXTEND THE ENGINE LIFESPAN BASED ON 1.4 GASOLINE ENGINE

2019-05-21T17:29:34+02:00

The article investigates the factory-made adjustments in the 1.4 liter gasoline engine construction used in an Opel Mokka as basis to determine the most common changes and adjustments made by vehicle manufacturers when producing vehicles intended to be powered with LPG. Comparisons are drawn to multiple other Opel vehicles, such as Adam, Astra, Meriva, and Insignia, all of which do have a factory-made LPG system installation. Other vehicle manufactures also offer new vehicles with a factory-installed LPG supply system. Among the considered vehicles are Hyundai i20, Dacia Sandero, and Skoda Fabia, as direct comparisons of the engine solutions applied to models designated for the addition of an LPG installation.

Keywords
LPG, engine, lifespan, alternative fuels

RESEARCH ON ELECTRICAL WIRING USED IN THE CONSTRUCTION OF WORKING MACHINES AND VEHICLES IN THE ASPECT OF FIRE PROTECTION

2019-05-21T17:29:36+02:00

Machines and equipment are characterized by various working conditions, and their parts change temperature depending on the principle of operation or the process being carried out. Wires in such devices should be resistant to high temperatures or insulated from heat sources. Danger of damage to cables due to high temperatures occurs not only in the case of structural faults, but also can occur during testing or diagnostics. Another cause of a fire may be the inflaming of installations during renovation work, for example when gas burners are used. The article presents the results of testing selected cables used in the construction of machines. The resistance to the degree of degradation of non-metallic constituents of conduits as a result of convection of heat was determined and the possibility of ignition of electric wires subjected to direct single flame operation was indicated together with the indication of the burnout section in case of ignition of non-metallic layers of the duct.

Keywords
construction of working machines, electrical wiring, fire protection

ANALYSIS OF VEHICLE’S SUSPENSION'S DYNAMIC RESPONSES DURING TEST TRACK RIDES AND REAL EXPLOITATION

2019-05-21T17:29:38+02:00

The following paper presents a study of dynamic responses of a passenger vehicle in typical exploitation conditions. It describes the process of acquiring data from the test rides and their further analysis using statistical values using MatLab. The analysis focuses on accelerations of sprung and unsprung mass, suspension deflection and its speed, comparing the values achieved on different road surfaces, taking into account safety limits and suspension characteristic. The data acquired are presented as graphs of density of probability and cumulative empirical probability, as well as tables listing dynamic responses undergoing analysis. The results allow for estimation of expected dynamic responses of a vehicle, thus making the preparation of future experiments more thorough.

Keywords:
suspension, dynamic responses, kinematic excitation

SAFETY OF AIR OPERATIONS IN TRAINING COMPETITION AND AEROBATIC SHOWS

2019-05-21T17:29:40+02:00

A question of exact determination of an aircraft (a/c) position and of its basic parameters is very important for the process of pilots training and for aerobatics performance. Therefore, a need for implementation of an intelligent and autonomic system enabling real-time flight control has arisen. Methods of flight course control and of aerobatic or training flight assessment used so far are not adequate in 21st century. The perspective of implementation of a real-time system for control and flight operations safety will enable conducting operations and analyses of flight course on a higher level than it is now.

Keywords
flight safety, safety models, safety management, navigation systems, collision avoidance system

MODELING AND SIMULATION OF THE THERMODYNAMIC OPERATING CONDITIONS OF THE CI ENGINE

2019-05-21T17:29:42+02:00

The article presents comparative results of a diesel combustion engine (AVL 5804) along with their simulation analysis. The simulation was performed using the AVL Fire 2017 software. The article focused on the indicated pressure changes in the compression and expansion strokes and on the fuel combustion process. Based on the recorded pressure characteristics in the engine cylinder and its basic construction data, a simulation was per-formed in which specific initial conditions and models of injection, evaporation and fuel combustion were included. A close resemblance between the test results and the simulation results was observed. The largest discrepancies in the analyzed quantities concerned the pre-flame processes, which means that these issues should inform about the quality of the pressure characteristic and the heat release rate modeling in the cylinder of the internal combustion engine.

Keywords
simulation, modelling, dynamic processes

ANALYSIS OF THE USE OF A HYBRID DRIVE SYSTEM IN URBAN TRAFFIC CONDITIONS

2019-05-21T17:29:44+02:00

The continued reduction of fuel consumption by vehicles leads to an increase in the share of hybrid and electric vehicle drives in the automotive market. There are many approaches, such as to focus only on the introduction of electric vehicles, however, using this type of drive requires additional infrastructure, reconstruction of many systems and has a long charging time, with which consumers are not entirely satisfied. Therefore, one of the leading types of passenger car drives is currently a hybrid drive. It does not require reconstruction of the entire infrastructure, only changes in vehicle drive systems. The costs related to this are relatively small compared to, for example, the construction of a network of new charging stations. Knowing the electric drive operating share in a vehicle with a hybrid system is used as a determinant of the profitability of using electric drives. The article estimated the share of electric and hybrid mode operation in urban traffic conditions. The research object was a Toyota C-HR vehicle equipped with a fourth generation hybrid drive. The analysis of the drive's operation allowed to determine the conditions of energy flow and determine the share of electric mode operation in the total driving time and in relation to the distance travelled.

Keywords
hybrid vehicle, drive modes, energy flow