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Anthropogenic activities involve the extraction, transformation and use of natural resources. During the process of extracting useful mineral substances on the surface or underground, particles or gases appear in the work environment resulting from the removal or natural release from the rock mass. The process of transforming useful mineral substances takes place on the surface in closed premises and involves the use of complex technological processes. During these, gases, fog, dust or powders of an explosive or toxic nature can be released or reach the working atmosphere. Industrial pollutants in confined spaces are released into the atmosphere for worker safety. If workers are caught in fires or explosions caused by flammable or explosive substances, morbidity is extremely high. The paper presents the CFD analysis regarding the determination of methane dispersion dynamics at the level of a closed enclosure. Through the CFD analysis, the methane flow and dispersion paths were identified, respectively the areas with minimum concentrations in order to safely evacuate the workers.

The photosynthesis process of plant requires fast removal of surface contaminant of leaves. The removal of surface contaminants is highly related to the drainage capacity of the leaf. This paper conducted a comprehensive study on the drainage capacity of plant leaves. The effects of both leaf shape and leaf hydrophilicity/hydrophobicity are investigated. This paper uses Computational Fluid Dynamics (CFD) technology to simulate the drainage process of plant leaves. The numerical simulation results indicate that hydrophilic leaves requires the sharp parts on the edges to remove the water. On the other hand, the drainage capacity of hydrophobic leaves is independent of the shape of the leaves.

In numerical calculations, entrance lengths and volumes upstream of the control volume are commonly used to steady the flow and obtain more accurate results. This paper discusses the effect of the geometrical shape of the inlet on the results of the flow field. The study presents the results of a Computational Fluid Dynamics (CFD) simulation of a real model of nasal cavity created from CT images of one patient. Furthermore, the spherical and cubic volume in front of the nostril entrance is modeled. Within the results, the flow fields are observed in planes across the entire sinus from the nostrils up to the nasopharynx. The resulting flow fields from all the three models are compared with each other. The effect of the geometric shape before the entrance to the nostrils is discussed considering the model without the modeled volume. The model created from the CT data of one patient was modified in CAD software to create differently shaped volumes in front of the nostrils. The CFD calculations were performed using Ansys Fluent 2021 R1 software.

The research object of this paper is intercooler used in vehicle. In the paper, the intercooler’s work area is divided into internal flow field and exterior flow field. The author analyzed the structure characteristics of the intercooler fin, and established finite element model in computational fluid dynamics software-Fluent. The unstructured grid is used to mesh. The finite element model is imported to Fluent before simulation. The temperature and pressure of intercooler is shown in result nephogram, and the results show the temperature in exit is higher than requirement. The paper provides scientific basis for structure and performance optimization to intercooler.

The development of organs in the human body does not end at birth. During the first five years of life, changes occur in the respiratory tract, not only in terms of its dimensions but also in the way it is used. Efforts to provide non-invasive treatment in the form of medical aerosols administered to children´s lungs during this period must be supported by knowledge of the flow pattern that significantly influences their transport and deposition. Research related to flow patterns in the adult human respiratory tract is quite widespread and the phenomena that occur during inhalation in different parts of the respiratory tract have been widely documented. In the case of the paediatric respiratory tract, research is relatively scarce due to the age of the patient and the desire to minimise interference with the paediatric organism. At the Brno University of Technology, we have the geometry of the airway of a ten-month-old infant, a scaled model of an adult to match the geometry of a five-year-old child based on scientific knowledge and also an adult model of the human respiratory tract. These geometries, together with knowledge of respiratory physiology were used to compare the changes in airflow behaviour that occur in the trachea during the first five years and compare it to fully developed adult human geometry. Computational Fluid Dynamics was used to investigate the model using a Large Eddy Simulation approach. The periods of life captured by the geometries differ not only in their dimensional difference but also in their approach to airway use. The impact of these differences has been captured in the paper.

The present paper aims to numerically investigate the flow, heat transfer and entropy generation of some hydrocarbon based nanorefrigerants flowing in a circular tube subject to constant heat flux boundary condition. Numerical tests have been performed for 4 types of nanoparticles, namely Al2O3, CuO, SiO2, and ZnO with a diameter equal to 30 nm and a volume concentration of φ = 5%. These nanoparticles are dispersed in some hydrocarbon-based refrigerants, namely tetrafluoroethane (R134a), propane (R290), butane (R600), isobutane (R600a) and propylene (R1270). Computations have been performed for Reynolds number ranging from 600 to 2200. The numerical results in terms of the average heat transfer coefficient of pure refrigerants have been compared to values obtained using correlations from the literature. The results show that the increase of the Reynolds number increases the heat transfer coefficient and decreases the total entropy generation.

The paper presents the numerical results obtained with the use of the ANSYS FLUENT commercial code for analysing the flow structure around a two rectangles in line surface-mounted bluff bodies immersed in a boundary layer. The simulation of a configuration with a flow around objects has been done using both the steady and unsteady approaches. Effects of the inflow boundary layer thickness on the flow field, wall-shear stress and the grid resolution accuracy in predicting periodic vortex shedding from two tandem arrangement bodies are examined. It has been observed that the periodic vortex shedding is considerably reduced with an increase in the δ/H parameter.

For the effect of hydrodynamic parameters on the dynamic performance of wave energy devices is very significant, these parameters must be considered carefully when adjusting dynamic characteristics of devices. On the other hand calculating hydrodynamic parameter of devices accurately can guarantee rational dynamic property parameter adjustment. By using CFD technique and considering the definition of hydrodynamic parameters, the phase relationship between added mass and damp as well as the equation of forces, one new calculation method of hydrodynamic parameter was presented. Finally one example demonstrated the effectiveness of the new analysis method presented in this paper.

Predicting the effect of antenna wind load on servo system precisely is meaningful to ensure the safety of satcom antenna on operation, which can avoid overload operation. In this paper, the computational fluid dynamics is used to proceed numerical computation on the pressure distribution of the reflector and torque of drive shaft under different wind speed, windward angle and angle of pitch of the antenna. The simulation model is built under MATLAB/Simulink simulation environment, and the drive current of the antenna servo system is analyzed under wind load effect and ship swing. Then, a method of predicting drive current of antenna servo system according to the wind speed, wind direction and attitude of the antenna is concluded. And this method is verified by simulation at last.