OCTAVE BAND ANALYSIS OF CAR NOISE EMISSIONS AT DIFFERENT SPEEDS AND ON DIFFERENT PAVEMENTS

Noise from cars is one of the main sources of harmful pollution. In the presented paper, an octave frequency band analysis is conducted according to standard methods of external and internal noise measurement. Experiments at different speeds, with three types of cars—conventional gasoline (GV), hybrid (HEV) and pure electric (BEV)—were carried out on two types of pavement—damaged coarse-grained and smooth fine-grained asphalt. The results show variations in external and internal noise levels vs. speed in different octave bands. At each speed, a spectral analysis was done. The diagrams with results show changes in noise level vs. speed and the positions of noise maximums. Regression models for the octave spectrum at different speeds and pavements are developed

RESEARCHING THE WAVEFORMS OF THE AUTOMOBILE ELECTROMAGNETIC ACTUATORS

This paper considers the signal waveforms of the control system of the automobile and automobile engines, their specific regions and possibilities of diagnostics and evaluation. The actuators signals, which are represented by waveforms, are an object of research for obtaining feedback for the condition of the processes and devices, which are the sources of these signals. The analysis of the waveforms is the precondition for diagnostics of the systems, into which these devices are integrated

A STUDY OF THE FUEL CONSUMPTION OF HYBRID CAR TOYOTA YARIS

The paper presents the experimental results from a complex study of the fuel consumption of a hybrid car Toyota Yaris. Original data for motion at different constant speeds are obtained. The economical and energy characteristics of the car are observed and analyzed. Three typical urban and three inter-city routes are investigated. A significant decrease in the fuel consumption of the hybrid car is witnessed when it runs in urban conditions at “Eco Mode”. The motion on inter-city route, including short town passages and highway parts, is also investigated. The obtained original data are higher than the fuel consumption given by the producer and, practically, equal to the ones of the conventional gasoline car. The study indicates that the effect of a hybrid system is significant in urban conditions and is more evident at “Eco Mode”

A STUDY OF THE INFLUENCE OF SOME EXPLOITATION FACTORS ON THE ATV STABILITY

An original survey among ATV riders concerning the conditions in which they lost stability is conducted. The coordinates of the center of gravity of the ATV by riders with different Body Mass Indexes are determined. A simulation program on base mechanic–mathematical model to study the ATV’s motion is used. In this base the critical sideslip velocities and critical lateral overturn velocities of ATV at various riders’ Body Mass Index, curve radius and grip coefficients were calculated. The results show that riders’ Body Mass Index strongly affects critical velocities because of different coordinates of center of gravity

Life cycle assessment of electric and conventional cars energy consumption and CO

This paper presents an analysis concerning the effectiveness of electric traction in comparison with conventional cars. The Life Cycle Assessment method is used. It estimates the energy spent for the extraction of the raw materials/sources, manufacturing and transportation of the components and the vehicle, motion, maintenance and repair during exploitation period and the recycling process. The impact of the production technology of the electric energy, needed for charging the battery, is taken into account. The energy consumption and CO2 emissions for the life cycle of electric and conventional cars are presented on graphs. Examples for Bulgaria and EU countries are given. The exploitation conditions in which the electric car is more effective regarding CO2 equivalent emissions are shown. The main influence on the effectiveness of electric cars has the structure of the energy mix of the country where the electric car is produced and is used in exploitation

AN EXPERIMENTAL RESEARCH ON THE WEAR OF TRUCK TIRE

Summary. An experimental device and methodology for tire wear investigation are presented. An indirect method for wear evaluating is used. The experimental results in cases of straight motion with and without side slip are obtained. The distribution of wearing on tread pattern wide is evaluated in different running conditions

Life cycle assessment of electric and conventional cars energy consumption and CO2 emissions

This paper presents an analysis concerning the effectiveness of electric traction in comparison with conventional cars. The Life Cycle Assessment method is used. It estimates the energy spent for the extraction of the raw materials/sources, manufacturing and transportation of the components and the vehicle, motion, maintenance and repair during exploitation period and the recycling process. The impact of the production technology of the electric energy, needed for charging the battery, is taken into account. The energy consumption and CO2 emissions for the life cycle of electric and conventional cars are presented on graphs. Examples for Bulgaria and EU countries are given. The exploitation conditions in which the electric car is more effective regarding CO2 equivalent emissions are shown. The main influence on the effectiveness of electric cars has the structure of the energy mix of the country where the electric car is produced and is used in exploitation