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

The integration of engineering support tools is essential for the efficient modeling, simulation, and optimization of complex technical systems. This paper presents a dynamic model of a micro-combined heat and power (mCHP) system, developed to validate the feasibility of integrating various computational environments. The approach leverages modular architectures, enabling seamless data exchange between distinct software platforms, thus supporting both detailed thermodynamic analysis and real-time performance optimization. The flexibility of this approach allows for the inclusion of diverse analytical frameworks, including neural network-based optimization, data-driven control strategies, and alternative programming languages, without being limited to a single computational tool. This adaptability makes the proposed architecture particularly suitable for evolving engineering applications, where rapid prototyping and iterativ e refinement are critical. The study highlights the potential of such integrated environments to enhance the design and operational efficiency of energy systems, providing a scalable foundation for future expansions.

Simulation of gravity filling a metal mold with aluminum alloy (EN AC-46400 AlSi9Cu1Mg)

The objective of the simulations is to calculate the total resistance and visualize the flow around a bare hull of a boat motion in deep and shallow water. Ship resistance is an important issue for ensuring smooth propulsion in various speeds in open sea and especially in the increasing influence of shallowness. Subcritical speed range in open shallow water is the main interest regime. A limited number of cases in critical and supercritical speed regions are applied in computations for comparison. For the full-scale bare ship-shape body resistance tests, computational fluid dynamics techniques and SST k-omega turbulence viscous model were employed. All calculations were carried out considering the influence of the free surface effect in a fluid. For convenience of mesh generation, an automated structured polyhedral meshing was adopted for the delicate curved surface and the domain. CFD solver interFoam – OpenFOAM, is applied to execute all computations in this article. The numerical model was initially built in FreeCAD, an open computer aided design (CAD) software and discretized in the cfMesh, a library implemented on top of the OpenFOAM framework. Post-processing is performed within ParaView, an application for scientific visualization. All software is free.

The article The article describes a simulation experiment to assess human behavior during threats inside buildings, using Metaverse systems and virtual reality (VR). The study was carried out on a model of a real building, where avatars controlled by users simulated responses to crises. This approach has several advantages over the traditional use of NPCs (non-player characters). Usercontrolled avatars enable a more realistic representation of behavior, as participants can make decisions in real time depending on the developing situation. Unlike NPCs, whose reactions are pre-programmed and predictable, human-controlled interactions introduce an element of unpredictability and authenticity, better reflecting real human reactions. Thanks to Metaverse and VR systems, it is possible to precisely reproduce building interiors and threat scenarios, which allows for analyzing various evacuation strategies and behaviors in stressful situations. In addition, experiment participants can repeatedly participate in various simulations, which increases the scope of collected data and allows for a more comprehensive analysis. The article emphasizes that using Metaverse and VR systems for simulations with users brings significant benefits to research on security and crisis management. This approach allows for the creation of more realistic models of human behavior, which are key to improving evacuation procedures and responses to threats inside buildings. The study presents the results of research carried out based on an original solution implemented in the Metaverse environment.

The prediction of maneuverability is a classic problem in ship hydrodynamics. Likewise, ship motions in restricted waters have been studied for a long time. It is an indisputable fact that full-scale or model tests of the respective ship meet IMO requirements and provide the necessary information for the maneuverability of the ship in deep unconfined waters. However, they are unable to provide practical insight into understanding of ship maneuverability in shallow water, as the maneuvering behavior of a ship in such areas differs significantly. Ship maneuvering in coastal areas and harbor approaches, where space is limited, movement speeds are low, and traffic heavier requires deeper researching. The aim of the present work is to predict the hydrodynamic derivatives in the mathematical model of the maneuvering of ship in shallow waters based on CFD programs with free access like FreeCAD, OpenFOAM and ParaView.
The sequence of solving the task is described with details in this work:
1. Generating the shape of the studied body 2. Creating the domains around the experimental body, sizes and boundaries
3. Defining the continuum, areas and subareas of study, and boundary conditions 4. Generation of the computational grid
5. Defining the continuum – physical models 6. Selection of the calculation algorithm 7. Substances modeling 8. Motion modeling.
9. Modeling of currents and energy 10. Flow turbulence modeling.
Results have been obtained for the linear hydrodynamic derivatives in the mathematical model for the maneuvering motion of a ship.
They are compared with available experimental and theoretical data in the literature.

The new platforms coming out on the social media space are faced from the beginning with a fierce contest. The competition for user attention is hard and the main players (Facebook, TikTok, Instagram, Reddit) have a huge advantage. To overcome these problems many of the newly lunched platform are making use of gamification strategy to keep the user engaged. The gamification strategy usually provides the user with a form of digital reputation but on some platform, it can be even a form of digital currency which can be exchanged for benefits or real products. To validate the user actions there is not always an automatic process, and the platforms are relaying on the community to cross-validate the authenticity and the value of the respective actions. The validation of the user actions can be automated but not always. When the validation cannot be automated, and the task requires human intervention the process is in his most part outsourced to the community and only a small number of the validation will be done by platform operators. The validation done by the platform operators will give credits to the users whose actions were validated. After certain amount of credit is given to a user, he became trusted, and his action can validate the actions of other users. The trusted user will act almost as a platform operator by validating other users’ actions. In this paper we simulate and analyse how the trust can be propagated into different social networks configuration. We start by defining a mathematical framework for modelling the users and the actions. After we introduce two different algorithms for propagating the trust in the community and finally for each configuration, we simulate the propagation of the trust and discuss the results.

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.

Generally, passenger ride comfort can be interpreted as an attenuation of sprung mass acceleration or as peak minimization of sprung mass vertical displacement, while good handling can be characterized as an attenuation of unsprung mass acceleration. This effort devoted to passive suspension design is ineffective because improvements to ride comfort are achieved at the expense of handling and vice versa. Instead, the best result can be achieved by active suspension, i.e. when an additional force can act on the system and simultaneously improve both of these conflicting requirements. Another important goal of the control design is to maintain robustness of the closed loop system. In the paper, fuzzy logic is used to simulate active suspension control of a one-half-car model. Velocity and acceleration of the front and rear wheels and undercarriage velocity above the wheels are taken as input data of the fuzzy logic controller. Active forces improving vehicle driving, ride comfort, and handling properties are considered to be the controlled actuator outputs. The controller design is proposed to minimize chassis and wheels deflection when uneven road surfaces, pavement points, etc. are acting on tires of running cars. As a result, a comparison of an active suspension fuzzy control and a spring/damper passive suspension is shown using MATLAB simulations.

The idea of creating and using digital twins has been strongly influenced by the process of integrating artificial intelligence methods with big data analytics of data from Internet of Things (IoT) devices. The concept of “Digital Twin” has become increasingly influential and culminating in the field of CPS. The main objective of the study is to define the basic requirements to the digital twins for cyber-physical system and based on the different definitions and components of digital twins, to summarize and analyze approaches, methods and tools used for their development. This analysis should serve as a basis for the development of a methodology for creating digital twins for cyber-physical manufacturing systems in the process industry.

In the paper are presented theoretical analysis of the methods for industrial processes modeling and a new approach to modeling and simulation of industrial processes in cases of lack of information on the mechanism of the process.

This paper presents investigations of vibrations of cantilever beams with piezoelectric layers. The paper discusses the contemporary engineering and scientific software systems in order to select the appropriate for the study of mechanical and electrical dynamic behavior of piezoelectric beams.The system COMSOL has been chosen and a study with it has been stated with a static analysis and an eigenvalue analysis. Conclusions are made and a frequency response and time dependent investigations are planned to be done.

In modern industry self-powered devices are an important component. For such devices, the most important component is the energy storage device used, most often based on lithium-ion technology. The article presents an equivalent circuits of lithium-ion batteries and a mathematical description of charge-discharge processes. Investigated in Matlab / SimPowerSystems built-in library component of lithium-ion battery. Mathematical models of equivalent circuits of different types of lithium-ionic batteries have been analyzed.