Journal of Engineering Sciences
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The creation of energy-saving turbogenerators is an essential component of the development of small energy systems. The gradual growth of interest in distributed electricity generation necessitates the constant improvement of these units. Moreover, they implement a more environmentally friendly generation method than when using microturbine units that use fuel to carry out the work process. Nowadays, turbogenerators are created based on different types of expansion machines, which have their advantages and disadvantages, given in this article. Compared to competitors, vortex expansion machines have good prospects and the necessary potential to expand their research and produce turbogenerators. An experimental vortex expansion machine with a peripheral-lateral channel and ability to change the geometric parameters of its flowing part was created to meet these needs. Experimental studies of the machine were performed on a special stand with air as a working fluid. As a result of the tests, the data were successfully obtained and processed. They are presented in the form of tables and graphical dependencies. The nature of the influence of thermodynamic parameters and geometric parameters of the flow part on the efficiency of the vortex expansion machine and turbogenerator based on it to further improve and create new turbogenerators is clarified.

Up-to-date directions in the development of modern industry increase the requirements for the quality of technical products. The design and manufacture of competitive process equipment require accuracy, productivity, and efficiency. Therefore, in this article, a new mechatronic system has been designed and developed to help porous, permeable materials with predicted porosity have been produced. The research aims to develop a mechatronic system for technology optimization in manufacturing permeable porous materials with controlled properties. As a result, the method of computer modeling of porous, permeable materials was developed. It allows us to consider the peculiarities of porosity distribution and radial velocity in radial isostatic compression. Additionally, a new mechatronic system for producing permeable materials allows us to determine the porosity distribution and particular characteristics of permeable powder material. The proposed approach allows us to evaluate the impact of technological modes on the main operational characteristics.

An increase in fuel utilization to internal combustion engines, variation in gasoline price, reduction of the fossil fuels and natural resources, needs less carbon content in fuel to find an alternative fuel. This paper presents a comparative study of various gasoline blends in a single-cylinder two-stroke SI engine. The present experimental investigation with gasoline blends of butanol and propanol and magnesium partially stabilized zirconium (Mg-PSZ) as thermal barrier coating on piston crown of 100 µm. The samples of gasoline blends were blended with petrol in 1:4 ratios: 20 % of butanol and 80 % of gasoline; 20 % of propanol and 80 % of gasoline. In this work, the following engine characteristics of brake thermal efficiency (BTH), specific fuel consumption (SFC), HC, and CO emissions were measured for both coated and non-coated pistons. Experiments have shown that the thermal efficiency is increased by 2.2 % at P20. The specific fuel consumption is minimized by 2.2 % at P20. Exhaust emissions are minimized by 2.0 % of HC and 2.4 % of CO at B20. The results strongly indicate that the combination of thermal barrier coatings and gasoline blends can improve engine performance and reduce exhaust emissions.

The tool with grooves on its working surface is used to improve the properties of the strengthened layer. This allows us to reduce the structure’s grain size and increase the thickness of the layer and its hardness. Mineral oil and mineral oil with active additives containing polymers are used as a technological medium during friction treatment. It is shown that the technological medium used during the friction treatment affects the nature of the residual stresses’ distribution. Thus, when using mineral oil with active additives containing polymers, residual compressive stresses are more significant in magnitude and depth than when treating mineral oil. The nature of the residual stresses diagram depends on the treated surface’ shape. After friction treatment of cylindrical surfaces, the highest compressive stresses near the treated surface decreases with depth. And after friction treatment of flat surfaces near the treated surface, the compressive stresses are small. They increase with depth, pass through the maximum, and then decrease to the original values. The technological medium used during friction treatment affects residual stresses in the grains and in the crystal lattice.

Despite the rapid development of alternative energy sources, the role of hydrocarbons in the global fuel and energy balance remains significant. For their transportation and further processing, pre-processing is carried out using a set of equipment. In this case, the mandatory devices are separators. In terms of specific energy consumption and separation efficiency, methods based on the action of inertia forces are optimal. However, standard designs have common disadvantages. A method of dynamic separation is proposed to eliminate them. The proposed devices are automatic control systems. The object of regulation is hydraulic resistance, and elastic forces are the regulating actions. Aerohydroelastic phenomena accompany the operation of dynamic separation devices. Among them, the most interesting are flutter and buffeting. Oscillations of adjustable baffles accompany them. It is necessary to conduct a number of multifactorial experiments to determine the operating parameters of dynamic separation devices. In turn, physical experiments aim to identify patterns and features of processes occurring during vibration-inertial separation (i.e., the dependence of various parameters on velocity). Therefore, the article proposes a methodology for carrying our physical experiments on dynamic separation and a designed experimental setup for these studies. As a result, the operating modes of separation devices for different thicknesses of baffle elements were evaluated. Additionally, the dependences of the adjustable element’s deflections and oscillation amplitudes on the gas flow velocity were determined for different operating modes of vibration separation devices.

In this paper, the heat transfer optimization (HTO) algorithm and simulated coronary circulation system (SCCS) optimization algorithm has been designed for Real power loss reduction. In the projected HTO algorithm, every agent is measured as a cooling entity and surrounded by another agent, like where heat transfer will occur. Newton’s law of cooling temperature will be updated in the proposed HTO algorithm. Each value of the object is computed through the objective function. Then the objects are arranged in increasing order concerning the objective function value. This projected algorithm time “t” is linked with iteration number, and the value of “t” for every agent is computed. Then SCCS optimization algorithm is projected to solve the optimal reactive power dispatch problem. Actions of human heart veins or coronary artery development have been imitated to design the algorithm. In the projected algorithm candidate solution is made by considering the capillaries. Then the coronary development factor (CDF) will appraise the solution, and population space has been initiated arbitrarily. Then in the whole population, the most excellent solution will be taken as stem, and it will be the minimum value of the Coronary development factor. Then the stem crown production is called the divergence phase, and the other capillaries’ growth is known as the clip phase. Based on the arteries leader’s coronary development factor (CDF), the most excellent capillary leader’s (BCL) growth will be there. With and without L-index (voltage stability), HTO and SCCS algorithm’s validity are verified in IEEE 30 bus system. Power loss minimized, voltage deviation also reduced, and voltage stability index augmented.

Direct current (DC) servomotor-based parabolic antenna is automatically positioned using control technique to track satellite by maintaining the desired line of sight for quality transmission and reception of electromagnetic wave signals in telecommunication and broadcast applications. With several techniques proposed in the literature for parabolic antenna position control, there is still a need to improve the tracking error and robustness of the control system in the presence of disturbance. This paper has presented positioning control of DC servomotor-based antenna using proportional-integral-derivative (PID) tuned compensator (TC). The compensator was designed using the control and estimation tool manager (CETM) of MATLAB based on the PID tuning design method using robust response time tuning technique with interactive (adjustable performance and robustness) design mode at a bandwidth of 40.3 rad/s. The compensator was added to the position control loop of the DC servomotor–based satellite antenna system. Simulations were carried out in a MATLAB environment for four separate cases by applying unit forced input to examine the various step responses. In the first and second cases, simulations were conducted without the compensator (PID TC) in the control loop assuming zero input disturbance and unit input disturbance. The results obtained in terms of time-domain response parameters showed that with the introduction of unit disturbance, the rise time improved by 36 % (0.525–0.336 s) while the peak time, peak percentage overshoot, and settling time deteriorate by 16.3 % (1.29–1.50 s), 43.5 % (34.7–49.8 %), and 7.6 % (4.35–4.68 s), respectively. With the introduction of the PIDTC for the third case, there was an improvement in the system’s overall transient response performance parameters. Thus to provide further information on the improved performance offered by the compensator, the analysis was done in percentage improvement. Considering the compensated system assuming zero disturbance, the time-domain response performance parameters of the system improved by 94.1, 94.7, 73.1, and 97.1 % in terms of rising time (525–30.8 ms), peak time (1,290–67.9 ms), peak percentage overshoot (34.7–9.35 %), and settling time (4.35–0.124 s), respectively. In the fourth case, the compensator’s ability to provide robust performance in the presence of disturbance was examined by comparing the step response performance parameters of the uncompensated system with unit input disturbance to the step response performance parameters of the compensated system tagged: with PID TC + unit disturbance. The result shows that PID TC provided improved time-domain transient response performance of the disturbance handling of the system by 91.0, 95.4, 80.0, and 93.1 % in terms of rising time (336–30.5 ms), peak time (1500–69.1 ms), peak percentage overshoot (34.7–10.0), and settling time (4.68–0.325 s), respectively. The designed compensator provided improved robust and tracking performance while meeting the specified time-domain performance parameters in the presence of disturbance.

This paper aims to design a new model of the third-stage carrier assembly used in a planetary gearbox as a single part component with improved strength and fatigue life properties and lower production costs. First, the mounting carrier assembly is subjected to static, fatigue, and modal analysis, and based on obtained results, the operating conditions that ensure its trouble-free operation are proposed. In the next step, new designs of the carrier as a single piece component are proposed and subjected to similar analyses. The proper numerical analysis method is chosen to evaluate the fatigue life, total deformation, and von Misses stress for each new model. Based on these results, the best design is chosen and submitted to further improvement, ensuring a weight reduction of 5 %. This last model of the carrier assembly is the most optimal solution since the maximum deformation values decreased by more than 55 %, and the maximum von Misses stresses decreased by almost 38 %, which increased fatigue life. A more comprehensive range of operating conditions for the optimized carrier is proposed to ensure its suitability for use in each gearbox. The finite element method analysis is performed in ANSYS.

Cold spray technology can obtain coatings in a solid state, suitable for deposition protection, repair, and additive manufacturing. In order to further expand the application areas of cold spraying nozzles, especially the inner surface of the components or areas where a Straight-line conical nozzle cannot be applied, because the study of the throat of the nozzle with the angle will directly reduce the total length of the nozzle (the horizontal direction), hence, the spray with the angle will show its advantage. This study discusses the influence of the throat structure of the conical cold spray nozzle on the acceleration characteristics, including the throat’s size, length, and angle. The results show the following. Firstly, under the premise of keeping the shrinkage ratio and divergence ratio unchanged at normal temperature, the throat diameter is between 2–6 mm in size, and the maximum growth rate exceeds 20 m/s. When the throat exceeds 6mm, the growth rate of the outlet slows down, and the growth rate is only 8 m/s. Secondly, the length of the throat has little effect on the acceleration characteristics, the total range fluctuated from 533 to 550 m/s, and 11 mm length of the throat is the closest to 0mm. Additionally, the 90° throat angle has the least effect on the acceleration characteristics. Finally, the particle trajectory is affected by inlet pressure, injection pressure, particle size, and other factors.

This research work investigates the durability-based properties of a ternary calcined clay and limestone powder blended Self Compacting Concrete by measuring the short- and long-term permeation properties using water absorption and sorptivity properties testing. Also, the variation of compressive strength with age was evaluated at 7, 14, 28 and 56 days, while the split tensile strength was determined at 7 and 28 days curing. The Mineralogy and morphology of the ternary SCC was evaluated using FT IR Spectroscopy, SEM imaging and EDS. The results obtained shows that the ternary SCC showed improved durability and strength properties with age with dense and improved microstructure.