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

Mathematical methods of quantum mechanics are needed to describe the contact phenomena of the boundary casting/mold. Apart from the macro-level, the contact phenomena are part of the technological processes first order phase transition and second order phase transition. Need for professional software for mathematical simulation at macro- and micro-level in foundry. Education in basic mathematics and mathematical physics is also required for engineers. The branch machine-building infrastructure must develop a mechanism for inclusion in the computing infrastructure of the micro-foundries.

This paper describes the process of drying baking soda in a pneumatic dryer. A description of a drying plant with honeycomb elements is provided. Due to the extensive work, only one part of the results of the study is presented, which is related to the material-energy balance, the calculation of the final humidity, the change of the air condition (humidity and temperature) in the bicarbonate drying process. Part of the research results related to the application of I-X – diagram in the drying process of Na HCO3 is presented

In this study, tube side thermal and hydraulic performance of a mini channel shell and tube heat exchanger (MC-STHE) designed using Kern method was investigated experimentally for water and α-Al2O3/water nanofluids prepared in two different low volume fractions (0.02% and 0.2%). The average particle diameter of Al2O3 nanomaterial used in the preparation of nanofluids is 50 nm. The copper tubes (L/D=120) with inner diameter of 2 mm and outer diameter of 3 mm and a length of 240 mm were used in the MC-STHE. During the experiments, shell side water flow rate was kept constant at 180 L/h, while the water and nanofluids flow rates on the tube side were changed between 60-600 L/h. The use of nanofluids in the MC-STHE deteriorates tube side convective heat transfer coefficient in the flow rates below 125 L/h, while enhancing convective heat transfer coefficient in the flow rates above 125 L/h, compared to water. The enhancement ratios for convective heat transfer coefficient compared to water were found to be 0.82-1.66 for 0.02% Al2O3/water and 0.9- 1.74 for 0.2% Al2O3/water in the range of 60-600 L/h volume flow rates. However, in the applications in which enhancement of the heat transfer is desired, it was obtained that the increase in pumping power should be taken into consideration depending on the selected nanofluids volume fraction. According to efficiency index in which increase in heat transfer and pressure drop compared to water are evaluated together, it was found that the use of nanofluids was significant in the flow rates above 375 L/h for 0.02% Al2O3/water and in the flow rates above 300 L/h for 0.2% Al2O3/water. The use of mini-channel increased the compactness by decreasing the weight and volume of the heat exchanger, and in addition to this, higher heat transfer coefficients were obtained by using nanofluids instead of water.

The main task of the research is to establish the regularities of the formation of a non-detachable compound of thin-walled elements from the Ni-20Cr-6Al-1Ti-1Y2O3 alloy and to determine the functional condition of the influence of soldering modes on the physical-mechanical characteristics of the compound. It has been shown the modeling of temperature fields in ANSYS 18.1. It has been established that the process of vacuum soldering should take place at a temperature of 1350°C for 15-20 min; the strength of the resulting compound is 390-420 MPa when the sample is stretched. The obtained information can be used as a theoretical basis for the development of the manufacturing process of the elements of the spaceship heat-shielding system.

The main task of the research is to establish the regularities of the formation of a non-detachable compound of thin-walled elements from the Ni-20Cr-6Al-1Ti-1Y2O3 alloy and to determine the functional condition of the influence of soldering modes on the physical-mechanical characteristics of the compound. It has been shown the modeling of temperature fields in ANSYS 18.1. It has been established that the process of vacuum soldering should take place at a temperature of 1350°C for 15-20 min; the strength of the resulting compound is 390-420 MPa when the sample is stretched. The obtained information can be used as a theoretical basis for the development of the manufacturing process of the elements of the spaceship heat-shielding system.

The modern world is facing two challenges – firstly, the energy crisis related to fuel the other – environmental degradation, especially in the form of air pollution and its consequences – climate change. The regulations demand specifically a significant reduction of sulphur oxide combinations (SOx), carbon dioxide (CO₂) and nitrogen oxide combinations (NOx).

The paper aims to study the combined effects of uniform magnetic field and inertia on a three-dimensional flow of a viscous fluid in a vertical channel. It is assumed that the fluid is injected into the channel through one side of the channel. The flow and heat transfer phenomena have been characterized by non-dimensional parameters R (cross-flow Reynolds number), M (magnetic parameter), Pe (Peclet number), and 𝛼𝛼 (heat generation parameter). The basic equations governing the flow and heat transfer are reduced to set of ordinary differential equations using the appropriate transformations for velocity components and temperature. These equations have been solved approximately subject to be relevant boundary conditions by employing a numerical technique. The effects of the above-mentioned parameters on the velocity and temperature distributions have been examined carefully.

The paper deal with heat pipe technology which is often used in electronic cooling from small voltage microchips to the high voltage electric elements. In case of cooling the high voltage electric elements have to be evaporator part and condenser part of heat pipe a separated by electrical nonconductive material, because the heat pipes are most often made of metallic materials, and thus, are electrically conductive. As a working fluids in this applications are used dielectric fluids such as fluorinert liquids. But there is still risk of the dielectric breakdown between evaporator and condenser of heat pipe. The task of the experiment is to find how the ambient temperature effect on dielectric breakdown of vapour phase of working fluid in heat pipe. In experiment was investigated dielectric breakdown between copper pipes inserted in to glass heat pipe in distance of 70 and 65 mm and temperature range -10 to -40°C. This distance simulate electric insulator distance of heat pipe used for real application of high voltage electric element cooling. For this experiment was used glass heat pipe with working fluid Fluorinert FC 72. The choice of this fluid is mainly due its excellent dielectric properties and unique combination of the thermodynamic and others properties, which makes the Fluorinert FC – 72 ideal fluid for electronic cooling used in many electronic applications.

Due to the increasing power requirements of the electronic components, which in many cases leads directly to increasing production of heat flux is the topic of the electronic cooling still current. In order to maintain their quality and lifetime as long as possible is the heat dissipation of electronic components solves by sophisticated technology such as a heat pipe technology. The paper deals with the cooling of power electronic component by loop thermosiphon. The loop thermosiphon is one from many proposal of heat pipe devices. Object of the paper is design and construction of the device to provide heat removal from the electronic component, thermal visualization of loop thermosiphon during operation, evaluation its cooling efficiency and research results interpretation. Paper describes function principle of loop thermosiphon, testing of the loop thermosiphon function and measurement of cooling efficiency in dependence on input electric power of the electronic component. The findings from measurement of loop thermosiphon cooling efficiency are compared with natural convective alumina cooler on the end of paper. The main object of the work is thermal visualization of heat flux transport by working fluid in loop thermosiphon from evaporator to condenser evolution. The result of the thermal visualization loop thermosiphon give us how the hydrodynamic and thermal processes which take place inside affect overall heat transport at start-up and during loop thermosiphon operation and distribution dynamics of the working fluid in dependence heat load.

This paper, concentrates on a three-dimensional (3D) computational fluid-dynamics (CFD) model for coal combustion and electrode radiation inside an electric-arc furnace (EAF). Simulation of the complete EAF model includes combustion reactions of coal particles and radiation from electrodes. Particle surface and gas phase reactions were used to predict injected coal particle combustion. The CFD model provided detail information for the coal particles combustion and radiation interactions phoneme inside the electric-arc furnace.

Results showed that CFD simulation could efficiently be used to develop and investigate EAF in design phase.