Технические науки. Рубрика в журнале - Бюллетень науки и практики
Experimental study on a pulsation-enhanced heat transfer device
Статья научная
The pulsation-enhanced heat transfer technology is introduced, and a volume coil heat exchanger is designed. A pulsation valve is installed at the heat exchanger outlet of the heat exchanger to pulsate the heat medium, and the same heat exchanger is subjected to pulsation and non-pulsation heat transfer tests. Based on the experiments, combined with the theory of pulsation-enhanced heat transfer technology, heat transfer capacity, heat flow, and convective heat transfer coefficient coefficients, the effective temperature difference, heat flow, and convective heat transfer coefficient of the heat exchanger at different pulse frequencies are analyzed. The relationship between the pulsation frequency of the heat transfer effect of the heat exchanger is obtained. The test results show that the heat exchanger has higher heat exchange efficiency when there is pulsation under the test conditions.
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Experimental study on heat transfer and pressure drop in plate heat exchanger using water-water
Статья научная
It would be misguiding to consider only cost in design of a heat exchanger because high maintenance costs increase total cost during heat exchanger’s services life. Therefore, exergy analysis and energy saving are very important parameters in heat exchanger design. In this study, the effects of pate heat exchanger (PHE, Ridan HHN no. 04) on heat transfer, friction factor and exergy loss were investigated experimentally. Experiments were conducted from laminar flow condition to turbulence flow condition under counter flow condition. Reynolds number and Prandtl number were in the range of 220
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Experimental study on heat transfer of pulsating flow enhanced the plate heat exchanger
Статья научная
We conducted two sets of experiments, one is under steady-state conditions and the other under pulsating conditions. We focused on measuring the heat transfer characteristics of plate heat exchangers under different pulsation conditions. In the experiment, we control the mass flow of the hot fluid to circulate at a rate of 0.722 kg/s. The mass flow rate of the cold fluid is 0.05-0.18 kg/s, and the pulsation frequency is 0.45-2.23 Hz. We measured different mass flows at different pulsation frequency. The data analysis shows that when the pulsation frequency is 1.78 Hz, the heat transfer coefficient reaches a maximum of 4415.73 w/(m2·k), and the corresponding cold fluid mass flow rate is 0.155 kg/s, and compared with the heat transfer characteristics of the plate heat exchanger under steady flow, it is found that the average increase in the heat transfer coefficient during the transition to the pulsating mode was 20%.
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Experimental study on unidirectional flow characteristics of flow diode
Статья научная
Flow diode is a kind of control fluid one-way flow of components, it has many advantages, such as simple structure, no rotating parts, no need for external control, power, high reliability, in the medical industry, nuclear industry, petrochemical industry, flow diode has a wide range of applications. By studying relevant literature, combined with the actual situation, based on the experimental study method, using air pump, pressure regulator, 3 d printers and other laboratory equipment, by changing the pump seal the air inlet, simulation of different flow diode under different conditions make the fluid flow through, will pump displacement into displacement, record each air inlet in unit time displacement, and then compared these data, the flow is obtained by carefully analyzing the flow characteristics of diode and the relationship between the fluid flow characteristics diode, it is concluded that: the displacement increases with increase of voltage; when the aperture changes, the flow diode will produce important changes; unstable flow characteristics of variable diameter flow diode.
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Статья научная
The article is devoted to the determination of the optimal parameters of a dielectric fluid as an impregnant in power capacitors. The optimal parameters for the synthesis of the ester are found on the basis of a not clear Mamdani model. The model providing optimization of the chemical process is offered and on the basis of statistical data, the algorithm of training of the fuzzy model is developed. The goal was solved with fuzzy data and a regression model of the three-stage process was obtained. Optimization was carried out and optimum parameters were found. Based on the statistical data, a fuzzy Mamdani model was compiled.
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Hadrian X - автономная роботизированная система для кладки кирпича
Статья обзорная
Рассматривается разработка инновационной системы для автономной кладки кирпича Hadrian X от компании Fastbrick Robotics, которая позволяет выстраивать дома из кирпича в автоматическом режиме без участия человека. Рассмотрены преимущества и недостатки данной разработки, а также области применения и перспективы развития в строительной области. Выявлены направления развития и совершенствования данной системы. Является лучшим способом строить типовое недорогое жилье за очень короткие сроки.
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High power led fish collector heat sink
Статья научная
High-power LED fish collector lamps are small in size and work with high heat flow density, LED chips emit more and more heat, and heat dissipation problems have gradually become a bottleneck limiting the development of LED. In this paper, for a typical power LED, it mainly discusses the LED packaging technology, the heat sink structure and characteristics of the impact on the heat dissipation conditions.
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Hot water heating circuit with impulse cavitator
Статья научная
An effective method of multifactorial influence on a liquid is cavitation, which leads to a change in the physicochemical characteristics of the liquid, its activation and heating. One of the devices, the principle of which is based on cavitation, is a cavitation heat generator. At present, the production of these units has been mastered by many manufacturers, and they appear in large numbers on the world market. Among the numerous designs of cavitation heat generators, a worthy place belongs to jet ones, which have the lowest pressure drop, but their efficiency is relatively low (from 20% to 40%) and does not meet modern requirements. The purpose of this work is to increase the efficiency of water heating in a cavitation heat generator based on the use of a pulsed mode of its operation. To achieve this goal, the following tasks were identified in the work: to develop a laboratory sample of a flow-pulse cavitator; to develop a diagram of a laboratory setup and a cavitator design; conduct hydraulic and thermal tests of the cavitator prototype, obtain the results and evaluate their effectiveness. Thus, the successful implementation of the goal of this work may encourage many industrial enterprises and households to abandon traditional heat supply systems and switch to modern sources of thermal energy, namely jet cavitation heat generators with a pulsed cavitator.
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How to learn and control effective hybrid cars
Краткое сообщение
The article deals with the history of hybrid cars, their types, running principle, parts, characters, advantages and negative features. Hybrid cars combine the efficient features of an electric motor and an internal combustion engine, and the use of hybrid cars in Azerbaijan, as in other countries, is satisfactory.
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Hydrodynamics of Absorption Bubbling Apparatus
Статья научная
The article proposes an improved design of the energy-saving, compact absorption bubbling apparatus, which cleans the particles and gas mixtures in the exhaust gases of industrial enterprises, has a high absorption efficiency. As a result of theoretical research, an equation has been proposed that calculates the value of the height of the gas cushion “h”, which provides equal distribution of purified gas to the mixing sections of the apparatus and operation in a stable hydrodynamic mode. As a result, depending on this value, it is possible to calculate the gas velocities and the gas consumption supplied to the apparatus.
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IPtables для обеспечения безопасности информационных сетей на базе Linux
Статья научная
В статье рассмотрены основные компоненты информационной безопасности: конфиденциальность, целостность и доступность. Пароли, шифрование, аутентификация и защита от проникновения - это методы, предназначенные для обеспечения конфиденциальности. Целостность означает поддержание данных в исходном состоянии и предотвращение их изменения: случайного или злонамеренного. Под обеспечением доступности информации понимают соответствие сетевых и вычислительных ресурсов ожидаемому объему доступа к данным и реализацию политики резервного копирования для целей аварийного восстановления. Для обеспечения безопасности информационных сетей на базе RedOS наилучшим образом показала себя утилита iptables, используемая для настройки брандмауэра ядра Linux. Несмотря на то, что на первый взгляд реализация IP-маршрутизации в Linux может выглядеть довольно сложной, на практике наиболее распространенные варианты использования (NAT и/или базовый брандмауэр Интернета) значительно проще реализуются. Iptables - это пользовательская утилита, позволяющая работать цепочками/правилами. В статье подробно рассмотрены принципы работы iptables, приведено подробное описание таблиц nat, mangle, filter, raw и цепочек. Таблица nat используется для трансляции сетевых адресов, mangle применяется для искажения пакетов, filter дает возможность выполнять фильтрацию пакетов, raw и ее цепочки используются перед любыми другими таблицами в netfilter. Цепочка input применяется для обработки входящих пакетов и подключений, forward - для проходящих пакетов, output - для исходящих пакетов. Показано, что для обеспечения безопасности функционирования компьютерных классов и всей сетевой инфраструктуры в целом, достаточно только двух таблиц: filter и nat. Другие таблицы предназначены для сложных конфигураций, включающих несколько маршрутизаторов и решений по маршрутизации. Приведены результаты использования iptables на основе опыта администрирования информационных сетей на базе RedOS в федеральном государственном бюджетном образовательном учреждении высшего образования «ПГУТИ».
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ISO 9000 quality standards implementation in the petroleum engineering plants of Baku
Статья научная
We carried out a comparative analysis of ISO 9000, API Ql, and the Russian GOST standards currently applied in domestic engineering plants to the manufacture of the oilfield equipment such as “xmas trees”, string heads, and well enclosing equipment.
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Improving Heat Transfer Efficiency in Systems with Low-Grade Heat Carriers Using Nanofluids
Статья научная
This article investigates the enhancement of heat transfer processes in energy systems operating with low-grade heat carriers through the application of nanofluids. Nanofluids, which are colloidal suspensions of nanoparticles in base fluids, demonstrate superior thermal conductivity and convective heat transfer properties compared to traditional fluids. The study includes a review of recent experimental and numerical research on nanofluid behavior in lowtemperature conditions, the selection of optimal nanoparticle materials, and the influence of concentration, flow regime, and surface characteristics on heat transfer performance. Results indicate that the use of nanofluids can significantly improve energy efficiency in low-temperature heat exchange systems such as geothermal plants, heat pumps, and solar collectors. Recommendations are provided for the practical integration of nanofluids into existing thermal systems, considering technical and economic factors.
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Increasing of magnetic devices lifting capacity and its efficience in shut down wells
Статья научная
The effectiveness of the point of application of force for lifting the objects from the bottom of oil and gas wells has been investigated. It the proven, that if the force to lift the deposited objects is applied not at the center of gravity of the object but at one end, then the force required is four times less than the force applied to the center of gravity of the object.
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Influence of at winglets wingtips on the inductive reactance of the wing
Статья научная
In this article by the method of equations of steady horizontal flight the impact of AT winglets wingtips on the inductive reactance of the wing is explored. The total aerodynamic force, created by all four parts of the wingtips is determined. The vector of the total aerodynamic force of the wingtips is represented in the form of components of a linked coordinate system. Equilibrium equations for the steady motion of an aircraft with AT winglets wingtips in a horizontal flight are recorded. From these equations it is obtained that, in the direction of motion, the longitudinal component of the vector of the total aerodynamic force of the tips reduces the inductive drag of the wing, the vertical component is added to the lifting force of the wing, and the lateral component, due to symmetry, is zero. It is shown that the lifting force created by the AT winglets wingtips is larger compared to the same ones created by the upper tips. An important consequence is that the distribution of the lifting force over the wing span with double tips is more even in comparison with the wing without a tip or with a wing with the upper wingtip. The expression for the effective aspect ratio of the wing with the tips is determined, which is greater than the inductive drag of the wing without the tip. An interesting result is obtained: for identical aircraft weights, the product of effective aspect ratio of the wings with double and only upper wingtips on their coefficients of inductive resistance is equal to the product of the wing aspect ratio without a tip on its coefficient of inductive resistance. This law can also be formulated as follows: at the constant weight of the aircraft, the effective aspect ratio of the wing with the tips by its coefficient of inductive resistance is a constant value, independent of the form of wingtips.
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Influence of wingtip type at winglets on the aerodynamic quality of wings
Статья научная
In this article by the method of equations of steady horizontal flight the impact AT winglets wingtips on the wing aerodynamic quality is explored. Determine the total aerodynamic force, created by all four parts of the endings. The vector of the total aerodynamic force of the endings is found in the form of components along the associated coordinate system. Equilibrium equations for the forces acting on the aircraft are recorded, with the linear motion of the aircraft with wing tips of the AT winglets type in a horizontal flight established. From these equations it is obtained that, in the direction of motion, the longitudinal component of the vector of the total aerodynamic force of the tips reduces the drag of the wing, and the vertical component increases the lifting force and this increases the aerodynamic quality of the wing. The components of the vector of the total aerodynamic force in the transverse direction from the left and right ends of the wing counterbalance each other By virtue of symmetry. Naturally, provided that the weight of the aircraft is constant and the speed of a straight horizontal flight, the angle of attack of the aircraft with the wing with endings like AT winglets should be reduced in order to observe the equality of the lift and the weight of the aircraft. A decrease in the angle of attack, in turn, leads to a decrease in the drag force. The effect of the aerodynamic wing tips on the maximum value of aerodynamic quality is studied. The expression for the aerodynamic lift coefficient at the most advantageous angle of attack is found. It is shown that the aerodynamic wing tips reduce the coefficient of lift of the wing without endings at the most advantageous angle of attack.
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Integrating AI and Digital Twins into Costume Design
Статья научная
This study presents a retrospective bibliometric analysis of publications in the Russian Science Citation Index (RSCI) database to examine the features of and underexplored areas in the use of artificial intelligence (AI) technologies and digital twins (DT) in costume design. In accordance with the PRISMA protocol, 247 relevant articles were selected and analyzed using descriptive, bibliometric, and substantive methods. Interest in AI increased from 2017, and DT development began in 2018. The leading journals were the "Journal of Clothing Science" and "Proceedings of Higher Educational Institutions. Textile Industry Technology," and the main authors were M.I. Alibekova and V.E. Kuzmichev. A four-stage chronology of AI evolution, from expert CAD systems to generative networks and Industry 5.0, and a five-stage classification of DTs, from static 3D models to "soft" twins and intelligent production lines that reduce defects by 22%, have been established. A five-level infographic has been developed to integrate AI and DT into costume design, with AI serving as a cognitive source and DT as a virtual body. The results provide an applied basis for introducing digital tools across all stages of the garment life cycle during the transition of enterprises to Industry 5.0.
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Investigation of diesel spray characteristics in low-temperature and low-pressure conditions
Статья научная
This study investigates the influence of altitude and injection pressure on diesel fuel spray characteristics, aiming to optimize diesel usage in high-altitude conditions. Experiments were conducted at three altitude levels (plains, 1670 m, and 2400 m) with corresponding atmospheric pressures and temperatures, alongside six injection pressures ranging from 50 MPa to 100 MPa. The investigation focused on key spray parameters: equivalence ratio, spray penetration velocity, turbulence kinetic energy, evaporation rate, spray penetration distance, and Sauter Mean Diameter (SMD). Findings indicate that increased injection pressure enhances spray penetration velocity, evaporation rate, and turbulence kinetic energy, while reducing SMD, irrespective of altitude. Conversely, higher altitudes were associated with increased spray penetration speed, larger SMD, decreased evaporation rate, increased turbulence, and a higher equivalence ratio. The study concludes that both altitude and injection pressure significantly impact diesel spray characteristics, providing essential theoretical support for the application and optimization of diesel fuels in varied altitude conditions.
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Logistic management of environmental safety of passenger transport
Статья научная
Analysis of air samples taken from the dense traffic sections of urban transport of different compositions revealed that the value of NOX, CXHy and CO emitted into the environment by vehicles depend on the traffic flow density and composition. It has been revealed that in those areas of the urban traffic networks where the urban passenger transport prevails in the traffic flow composition, the indicator of traffic-related air pollution is much higher, so the management of the road transport processes by using the logistical arrangements of the traffic flows should be carried out taking into account the environmental safety criteria. The paper dwells on three different levels of management of environmental safety of vehicles as follows: the mega-level of the formation of regional transport; the micro-level of management of passenger routes, and the individual level (driver - vehicle) of traffic management.
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Статья научная
Operational reliability assessment for overhead bridge cranes remains fragmented across structural reliability analysis, non-destructive inspection, condition monitoring, and remaining useful life prediction. Existing studies usually treat these directions separately: accident reliability is evaluated through fault-tree, Markov, and fuzzy Bayesian models; girder failure is assessed probabilistically under uncertain design parameters; structural integrity is examined through finite-element analysis and non-destructive testing; and fatigue or bearing degradation is predicted through damage accumulation and stochastic prognostic models. This paper proposes a unified mathematical framework for evaluating operational reliability indicators of overhead bridge cranes by combining three information streams: normalized defect severity, inspection evidence quality, and predicted remaining useful life. The framework defines component-level and system-level reliability indicators, introduces a confidence-adjusted defect severity index, applies Bayesian updating for new inspection cycles, and links degradation state to time-dependent hazard and reliability functions. The proposed indicators are designed to support maintenance prioritization, inspection scheduling, and continued-operation decisions for critical crane subsystems, such as girders, end carriages, hoisting mechanisms, wire ropes, brakes, wheels, and gearboxes. Although the study is methodological rather than experimental, it is structured for direct implementation using routine inspection sheets, non-destructive testing results, sensor-based monitoring data, and maintenance histories. The main contribution is an integrated decision-support formulation that preserves the mechanical meaning of defects while providing a probabilistic interpretation of operational reliability.
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