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

This study investigates the application of Computational Fluid Dynamics (CFD) to optimize the flow performance of a fire monitor. Geometric modifications were implemented and analyzed using CFD simulations, comparing the original design with a modified version. The results demonstrate that the optimized design achieved a notable increase in outlet velocity (0.76 m/s) and a significant reduction in internal pressure (13,328 Pa). These findings highlight the potential for design simplification to improve operational efficiency and reduce costs.

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.

A new method of cooling the outside air in ventilation systems of poultry houses is proposed, based on the use of water from underground wells and heat exchangers of recuperators for cooling the supply air.
Numerical modeling of aerodynamics and heat transfer processes in poultry houses at tunnel ventilation system was performed. As a result of numerous calculations the distribution of temperatures, velocities and pressures in the air environment of a poultry house has been obtained. The use of heat exchangers for cooling the supply air allows to maintain its temperature at the level of +20-25 ℃ and to reduce the indicators of moisture content in poultry houses, which are high when using cassette methods or water spraying with nozzles for cooling the supply air.
As a result of the numerous studies conducted, it is recommended to increase the air flow rate by including a third exhaust fan located on the top line of the end rear wall. This will allow for a more uniform temperature distribution in the house.

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.

Maintaining a standardized microclimate in the poultry house is one of the main factors. It is the quality of the air parameters that ultimately determines the quality of the product output. Poultry at its maintenance requires great efforts and technological solutions. In this regard, the study is to improve the system of microclimate in the air environment of the poultry house by including exhaust fans on the rear end wall in a non-traditional way. Computational Fluid Dynamics (CFD) using ANSYS Fluent is a powerful tool for predicting the microclimate system in the poultry house as an alternative to experimental studies. According to the results of CFD modeling of hydrodynamics and heat and mass transfer processes, it was concluded that changing the spoiler angle by 73° allows to supply air to the center of the house. At the same time the pressure drop at the inlet valves is 70.48 Pa, which allows to fully provide the exhaust fan. The air velocity at the inlet of the supply valves is 11.57 m·s–1. The average air velocity at a height of 0.7 m from floor level is 0.46 m·s–1and the temperature is 15.94 ℃. Thus, the presented scientific research can be used in the future in the development of new ventilation systems of poultry houses.

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.

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 purpose of the current study is to evaluate and apply a new approach to the design process of an aircraft with a high aspect ratio wing, based on modern understandings and development in the fields of aerodynamics and computational fluid dynamics. Conventional methods rely on semi-analytical models for describing different flow characteristics and interactions with bodies. The classical approach requires numerous coefficients to account for unknown effects, what is more, such workarounds are derived for well-defined cases and are not easily applicable for complex problems which could be dangerously misleading. CFD analysis, based on new developments in computational machines, give the possibility of analyzing complex aerodynamic interactions such as shading, downwash, ground effect and vortex shedding. Such use of innovative technology has already proven itself to have beneficial effect on reduction of cost a nd human error by being able to simplify and speedup many of the calculations without the need of coefficient adjustments.

In this paper, the impact of wind forces on human bodies is shown. Like many meteorological phenomena, the influence of wind energy applied to human bodies is inevitable which comes into the spotlight of the scientist only when the wind becomes violent and extremely disturbing. Based on weather and observations in February 2019, abnormal wind characteristics in Albania are evidenced. On February 23, 2019, a very special situation in the Northern part of Albania, the region of Puka, with extreme values of wind parameters causing the phenomenon of “wind gust”, leading to a series of material damage and loss of human life, is evidenced. Researchers and predictors need scientific information on the impact of strong winds applied on the human body for specific conditions. Wind speed values in this region of the northern part of our country set records reaching extremely values (30 ÷ 35) ms-1 on the ground level. Taking a cue from this unprecedented situation, the effect of strong winds on the determination of aerodynamic forces acting on the human body using numerical simulations has been studied and so far, well investigated. For this study, we considered a human body with a height of 172cm. The investigation takes into account two different positions against the wind, frontal and lateral position traversed by wind speeds levels of 20m/s, 30m/s, and 40 m/s. The study concluded that strong winds can exhibit unimaginable and unaffordable forces, leading to fatal consequences for human life.

The main scope of this paper is to fully integrate simulation from open source CFD software with the Matlab App Designer program. The OpenFOAM-Matlab CFD interface allows one to conveniently setup fully turbulent incompressible Reynolds Averaged Navier-Stokes (RANS) CFD case all within an easy to use graphical user interface (GUI). Highlighting built-in CAD tools to create geometry (STL) for automatic mesh generation to OpenFOAM case file as well as a solution with post-processing and visualization with ParaView. Also, the cross-platform OpenFOAM CFD interface for MATLAB should allow the user to rapidly design the spiral casing in an engineering manner as an illustrative platform and coordinator between the inputs chosen by the user and the results which are displayed after calculations. Furthermore, the GUI should be a very flexible and user-friendly platform for spiral casing design according to the efficiency and static pressure recovery coefficient as well.