International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

It is very important to know the trends related to the structure and condition of the vehicle fleet, to be able to predict the structure of the vehicle fleet in the future. In Montenegro, it is noticed that there is a constant increase in the number of battery electric vehicles (BEVs). The share of BEVs in the vehicle fleet of Montenegro is too small to have any significant impact on CO2 emissions as well as the power system. The pandemic COVID-19 virus had a great impact on the number of registered as well as the number of newly registered vehicles. Practically, in 2020, the year of the pandemic, only an increase in the number of BEVs was recorded. It is very worrying that the number of vehicles using diesel fuel is increasing, which can be a complicating factor in efforts to reduce the negative impact of road traffic on the environment.

It is often assumed that if practical difficulties are neglected, active suspension systems could produce in principle arbitrary ideal behavior. This paper presents the factorization approach that is taken to derive limitations of achievable frequency responses to active vehicle suspension systems in terms of invariant frequency points and restricted rate of decay at high frequencies. The factorization approach enables the determination of complete sets of such constraints on various transfer functions from the load and road disturbances for typical choices of measured outputs and then chooses the optimal vector of the measurements from the point of view of the widest class of the achievable frequency responses. Using a simple linear two-degree-of-freedom car suspension model, it will be shown that even using complete state feedback and in the case in which the system is controllable in the control theory sense, there are still limitations to suspension performance in the fully active state.

One of the biggest challenges in the FSAE competition is adapting the power unit to the strict regulations of the competition. The task of the exhaust manifold is to enable the best possible flow of exhaust gases from the engine to the environment. A properly designed vehicle exhaust manifold is of great importance for enabling better performance of the power unit. There are several different concepts for designing exhaust manifolds. Each concept has its advantages and disadvantages. One of the main guidelines when designing the exhaust manifold is to enable air flow with as little local resistance as possible so that the exhaust gases are released into the environment as soon as possible. In this work, a 3D model of three types of exhaust manifolds was created, and then a CFD simulation of airflow through exhaust manifolds was performed using ANSYS Fluent software. CFD simulations help to a great extent with a better design of the exhaust manifold.

In this paper, a simulation of their flow through the throttle valve on the Formula Student vehicle was performed throttle valve is an element that, according to the regulations of the Formula Student competition, must be present in the intake installation of the vehicle’s power unit if it is a competition in class IC. The correct design of the throttle is of great importance anchor or the power unit to work properly, but also to extract the maximum performance of the power unit itself, and thus of the competition vehicle as a whole. One of the main tasks of the throttle is to allow air to flow with as little resistance to flow as possible. For the CFD simulation in this work, ANSYS Fluent was used, which proved to be a very powerful tool in the CFD simulation of the throttle body.

Formula Student is a student engineering competition. Students all over the world compete to build a racing vehicle. One of the main elements of this vehicle is the vehicle chassis. The chassis is one of the most important elements from the aspect of driver safety. There are different chassis design concepts. The two most common are the monocoque chassis and the tubular chassis. In this paper, a detailed structural analysis of the tubular chassis of the Formula Student vehicle was performed using the software. The chassis model was created in the CATIA software, and then the structural analysis was done in the ANSYS software. By applying modern software, it is possible to better understand the problems during construction, and significant financial and time savings can be made. ANSYS software can also be of great help in chassis optimization.

The FSAE competition is a student engineering competition that involves designing, constructing, and building a small racing car. Students from different universities compete on auto-moto sports tracks. The competition’s judges are eminent experts in marketing, automotive engineering, and racing car engineering. In class IC, engines are used as power units. One of the main limitations is that all intake air must pass through a diameter of 20 mm. One of the main challenges facing student competitors is solving this problem, and the convergent-divergent jet is one of the possible solutions to the problem. In this paper, CFD simulations were used to examine the influence of the divergent part of the restrictor on the total mass flow at the nozzle exit. A diagram of the dependence of the mass flow on the half-angle of the divergent part was obtained. For the CFD simulation, ANSYS Fluent was used, which proved to be very good for examining the mentioned influence.

The Formula Student competition is the most challenging, complex, and attractive student engineering competition in the world. Students from universities around the world compete to build better vehicles. The competition consists of several different disciplines, which are divided into two groups. The first group consists of static disciplines, where students who are members of the team defend the vehicle project in front of eminent experts from the world of the automotive industry and auto-moto sports. The second group is the group of dynamic disciplines, which is made up of several disciplines related to the analysis of vehicle behavior in real conditions. One of the main challenges facing the team members is designing the vehicle’s propulsion system. At competitions in the IC engine class, power units from a certain class of motorcycles are most often used. The main limitation related to the power unit is that all intake air must pass through a 20 mm diameter. One of the solutions to the mentioned problem is the use of a convergent-divergent nozzle with a throat diameter of 20 mm. In this paper, the influence of the convergent part of the nozzle on the airflow through the nozzle itself was examined. Models were created for several restrictors and they were tested by CFD simulation in ANSYS Fluent software

The greater interest of people living in urban areas has been accompanied by an increase in demand for motorized movements and other forms of active movements in these areas. As a result, traffic problems have been increased extremely for these road users both in terms of the quality of movement and safety. This research is focused on identifying factors related to the quality of motori zed and nonmotorized movements in urban areas, a particular case study of the municipality of Fushe Kosova, and the design of a model for traffic optimization in urban areas. The current approach to prioritizing the solution of motorized traffic problems, especially in d eveloping countries, has proved ineffective because, in the absence of addressing other mobility requirements (pedestrian, cyclist mobility), road users have been encouraged more to use this form of transport, leaving no room for other alternatives. The research aims to apply advanced methods for handling and managing traffic problems based on the principle of inclusion and building a model for optimizing traffic operation based on a specific case. The model is built using the programming language “Synchro,” which enables the analysis, optimization, and simulation of all forms of transport: motorized traffic, movement of pedestrians and cyclists in the road network planned following these requirements. Obtained results show the advantages of using different forms of transport depending on the selected concept and the priority of certain forms of transport. The summary results and their comparison in terms of quality for different time intervals, including the different conditions of access to urban areas, are presented in tabular forms.

The paper deals with innovations in vehicle suspension technology developed in the Josef Bozek´s Research Center of Combustion Engines and Automobiles at CTU in Prague, Czech Republic. A unique innovative suspension system that uses a linear electric motor as a controlled actuator has been designed. Many experiments on the energy management in the system have been accomplished. In order to verify various control strategies and to test different ways of energy consumption optimization we designed and constructed a unique onequarter- car test stand. To realize simulation and practical experiments at the test stand it is necessary to find a proper experimental road disturbance signal to excite the active suspension system. The disturbance signal is applied on one more linear motor that is placed under a wheel of the one-quarter-car test stand to excite the active suspension system. The paper deals with the way and results of experimental verification of vehicle active suspension behavior when robust control is applied and also with energy management strategy that is used in the system. A modified H-infinity controller that enables to set energy management strategy is mentioned in the paper. At the close of the paper, some experiments taken on the one quarter-car model and their evaluation are discussed.

The hybrid electric vehicles (HEV) are promising vehicles with low exhaust emissions and increased autonomy of movement including internal combustion engine (ICE) and electric motor (EM) which is powered by the battery (B) . The main advantage of HEV over classic cars is the reduced fuel consumption, especially in urban traffic [1]. This is a prerequisite for good energy efficiency of HEV, which is determined by the fuel consumption and consumption, respectively the regeneration of electricity of HEV. These values depend on many factors such as speed, mileage, acceleration, mass, drag, climatic conditions and more. The modelling of the energy efficiency of HEV is related to the study and structuring of the factors that determine the fuel consumption and electricity consumption and the dependencies between them and their connection and construction in a model. The model of energy efficiency of HEV gives a quantitative assessment of the fuel consumption and the consumption (regeneration) of electricity of HEV, according to the main influencing parameters. In addition, the HEV energy efficiency model indicates the influencing parameters and their analytical or experimental determination. The correct modelling of energy efficiency is related to the correct determination of energy parameters and their logical connection in a selected model. The optimal model of energy efficiency of HEV is built from these factors that can be directly measured or calculated, which increases the accuracy and reliability of the results. This article discusses building an energy efficiency model of a hybrid electric vehicle.

In the paper, the design of a linear motor as an actuator in vehicle active suspension systems will be presented. The attention is focused on several interesting design aspects of a non-traditional actuator (a linear synchronous permanent magnet motor with electronic commutation) controlled to obtain a variable mechanical force for a car active suspension. The main advantage of such a solution is the possibility to generate desired forces acting between the unsprung (wheel) and sprung (car body) masses of the car, providing good insulation of the car sprung mass from the road surface disturbances. In addition, under certain circumstances it is possible to reduce or even eliminate the demands concerning the external power source.

In the paper, energy recuperation and management in automotive suspension systems with linear electric motors controlled using a proposed H∞ controller to obtain a variable mechanical force for a car damper is presented. Vehicle suspensions in which forces are generated in response to feedback signals by active elements obviously offer increased design flexibility compared to the conventional suspensions using passive elements such as springs and dampers. The main advantage of the proposed solution using a linear AC motor is the possibility to generate desired forces acting between the unsprung and sprung masses of the car, providing good insulation of the car sprung mass from the road surface disturbances. In addition, under certain circumstances using linear motors as actuators enables to transform mechanical energy of the vertical car vibrations to electrical energy, accumulate it, and use it when needed. Energy flow control (management) enables to reduce or even eliminate the demands concerning the external power source.