2018

Постійне посилання на фонд

https://eir.nuos.edu.ua/handle/123456789/3325

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Зараз показуємо 1 - 20 з 51

Analysis of the development and current state of the use of power plants based on pneumatic engines
(2018) Mytrofanov, O. S.; Митрофанов, А. С.
The article presents the main stages of development and use of compressed air energy in transport plants for various purposes. The domestic and foreign literature on the development of the current state and prospects of the use of compressed air energy and pneumatic engines in the power plant of vehicles have been analyzed. The list of problems arising in the application of pneumatic engines is determined, as well as rational ways of further increasing the efficiency of power plants are established. The main advantages and disadvantages of pneumatic engine using in the composition of transport power plants are highlighted. So, the main advantages include high environmental friendliness, depreciation of vehicle production, lower mass and dimensions parameters. Disadvantages include low efficiency coefficient due to multiple energy conversion, limited power consumption of filling cylinders and engine cooling due to the expansion of air. The most common pneumatic engine designs (piston and rotary) and their performance properties are considered. It has been established that rotary pneumatic engines, in terms of energy, mass and dimensions, and performance parameters, exceed other engines. Some of their inherent operational disadvantages, which may limit their use in some spheres, can be eliminated or reduced to acceptable standards at the right design solution. The variants of the basic schemes of power transport plants with pneumatic engines, namely the use of a pneumatic engine as an auxiliary power unit (hybrid units) or, as the main one in aeromobiles, are considered.
The application of nanostructural foil for diffusion welding of composite based on aluminum alloy 6061 containing 55 % SiC
(2018) Bugaenko, B. V.; Buturlia, Y. A.; Kvasnitskiy, V. V.; Kvasnitskiy, V. F.; Korzhik, V. N.; Бугаєнко, Б. В.; Бутурля, Е. А.; Квасницький, В. В.; Квасницький, В. Ф.; Коржик, В. Н.
The process of diffusion welding in vacuum (DWV) of an aluminum-based composite using nano-multilayer aluminum–nickel and aluminum–titanium foils is investigated. Aluminum alloy 6061 hardened silicon carbide (55 at.%). It has low ductility, which makes deformation activation of the surfaces being joined difficult. Therefore, DWV perform through the intermediate layer, for example, aluminum foil. In this work, the layers obtained by the method of electron beam deposition were used. In layers with alternating nanolayers with rapid heating, reactions of self-propagating high-temperature synthesis take place, in which the amount of generated heat is sufficient for additional heating of the composite and it’s melting, which ensures activation of the surfaces to be joined. At the first stage, the creep processes of the composite under DWV conditions are investigated, the parameters and the creep equation are determined, as well as the allowable deformations that do not cause cracks. For DWV, Al/Ni and Al/Ti foils with thicknesses of 20, 40, 50, and 94 microns were used. The effect of the thickness of the interlayers on the formation of compounds has been established. It is shown that, regardless of the interlayer system, at the majority of the junction metal has a composite structure with common grains and the boundary between the connected samples is not determined either by structure or by chemical analysis.
Assessment of rigidity of the designed intermittent connections in ship structures
(2018) Korobanov, Yu. N.; Kuznetsov, A. I.; Hrabenko, A. A.; Коробанов, Ю. Н.; Кузнецов, А. И.; Грабенко, А. А.
The article presents the assessment of rigidity of ship intermittent connections. The stress distribution and the values of rigidity coefficients of intermittent connections of the structure have been studied. The analysis is based on the results of computational procedures which follow the finite and boundary element methods to the contrary of the numerical methods used by other authors who cover the same topic. It has been established that there is a great variance and a lot of allowances in rigidity coefficients, as well as methods for their calculation. An analysis of methods for determining rigidity coefficients has shown that they cannot practically be introduced into the computer-aided system for ship structure design in the form presented in appropriate literary sources. In addition, the paper covers various ap-proaches to interpretation of the rigidity coefficients of intermittent connections and methods for their calculation using the example of a discontinuous plate. It is shown how to apply the finite and boundary element methods with their possible integration into computer-aided design systems.
Automation of the monitoring and control processes of a mobile robot for processing of large inclined surfaces
(2018) Kozlov, O. V.; Gerasin, O. S.; Kondratenko, Yu. P.; Kushnir, V. O.; Козлов, О. В.; Герасін, O. C.; Кондратенко, Ю. П.; Кушнір, В. О.
The article renders special features of the design of a tracked mobile robot (MR) for moving over inclined ferromagnetic surfaces while performing specified technological operations. There is conducted a synthesis of the functional structure and selective technological parameters (such as control coordinates) of the computerized monitoring and control system (CMCS) intended for use with this MR. Application of the CMCS with the proposed functional structure allows substantially increasing the accuracy of the MR monitoring and control, which in turn provides for a considerable enhancement in the quality and economic efficiency of the operations on processing of large ferromagnetic surfaces.
Conceptual model of project management for robotic water area clearing from underwater potentially hazardous objects
(2018) Hrytsaienko, Maksym H.; Грицаєнко, М. Г.
Антотація. Сформульовано науково-прикладне завдання управління проектами очищення акваторій від підводних потенційно небезпечних об’єктів. Реалізацію завдання пропонується виконувати шляхом застосування засобів морської робототехніки. Розроблено узагальнену концептуальну модель управління проектами роботизованого очищення акваторій на основі єдиного інформаційного простору проекту. Модель створена як чотирирівнева структура. Кожний рівень реалізується відповідними засобами морської робототехніки і пов’язаний з іншими за допомогою системи інформаційного обміну.
Creating an online platform for managing joint educational programs with foreign partners
(2018) Ryzhkov, O. S.; Ryzhkov, R. S.; Рижков, О. С.; Рижков, Р. С.
Distance education is the ideal solution for professionals who want to continue their careers. This makes it possible to obtain an additional qualification and save the current job. Distance learning programs can be the key to the career and promotion through a flex¬ible schedule and resources that are available on the Internet. During globalization and the rapid technology development, the functioning of the university as a full-fledged player of the international market cannot be imagined without the use of distance learning methods. The modern online platform “WeStudy” has been developed for the Ukrainian market of edu-cational services. The issues of using modern information and communication technologies are examined in order to improve the quality of educational services in the implementation of joint Ukrainian-Chinese projects. The programs between the Admiral Makarov National University of Shipbuilding and its two partners - Zhejiang University International College and Jiangsu University of Science and Technology are taken as a pilot.
Devices for maintenance of comfortable working conditions in floating docks
(2018) Shchedrolosiev, O. V.; Uzlov, O. M.; Konovalova, H. V.; Kyrychenko, K. V.; Щедролосев, О. В.; Узлов, О. M.; Коновалова, Г. В.; Кириченко, К. В.
Classification of ice-retaining devices has been presented; they allow docking vessels when there is a lot of ice in the water area. Schemes of the devices designed for closing the ends of floating docks are provided. They reduce the amount of draughts on the pontoon deck, which is especially relevant throughout cold autumn, partly winter, and spring. Schemes of the staff structures of dock scaffoldings are presented; the requirements for them are also described.
Devices for maintenance of comfortable working conditions in floating docks
(2018) Korol, Yu. M.; Liubytska, N. G.; Король, Ю. М.; Любицька, H. Г.
The towing resistance of the projects AVP 07, AVP 07m, AVP 09 and AVP 11 has been studied in accordance with the needs of Artel LLC. The AVP 07m differs from the AVP 07 by the shape of the bottom at the aft end; thus, the impact of this shape on resistance is assessed. For the AVP 09 with non-standard, simplified contours, its towing resistance is esti¬mated and its performance characteristics are defined. For the AVP 11 project, the effect of lat¬eral clearance on its towing resistance is studied. The main research method is CFD modeling.
Emergency modes of marine tethered systems
(2018) Trunin, Kostiantyn S.; Трунін, К. С.
Анотація. Розглянуто аварійні режими морських прив’язних систем (МПС), що мають у своєму складі гнучкий зв’язок (ГЗ). Розроблено класифікацію аварій і аварійних режимів МПС і ГЗ, що дає можливість більш повно визначити умови, що призводять до аварійних випадків і аварійних режимів МПС, які можливі в умовах їхнього функціонування, а також перейти до моделювання аварійних режимів роботи МПС із ГЗ.
Experimental study of group control laws for an autonomous unmanned underwater vehicle as a group agent
(2018) Burunina, Z. Yu.; Voitasyk, A. M.; Aloba, L. T.; Korytskyi, V. I.; Sirivchuk, A. S.; Klochkov, A. P.; Буруніна, Ж. Ю.; Войтасик, А. М.; Алоба, Л. Т.; Корицький, В. І.; Сірівчук, А. С.; Клочков, О. П.
Underwater works are effectively performed with the use of underwater vehicles. The use of groups of autonomous unmanned underwater vehicles for the monitoring of big volumes of underwater space is particularly effective. In this paper, modern approaches to group control of the motion of autonomous unmanned underwater vehicles are analyzed. The composition and configuration of the system of external environment sensors are proposed; the system allows an underwater vehicle to identify the presence of objects in close proximity and the direction of their motion. The structure of the automatic control system of a group of autonomous unmanned underwater vehicles in the mode of coordinated rectilinear motion is proposed. The system is based on the principle of subordinate control with the help of fuzzy logic controllers. The results of field trials of the system operation in the adhesion and cohesion modes of two underwater vehicles confirm the operability of the proposed approach.
Heat transfer inside the rough-walled tubular channels of power plant elements
(2018) Kuznetsov, V. V.; Кузнецов, В. В.
Tubular channels with rough walls are now widely used for the formation of heat transfer surfaces of heat exchangers, which must meet the technical and economic requirements for power plants. Among these requirements, intensity and compactness are the main ones. The implementation of these requirements is possible with the intensification of heat transfer processes in a confined space. As shown by prior studies, the intensification of heat transfer on rough surfaces is based on a complex analysis of the effect of roughness in geometric parameters and thermophysical properties of heat agents on their efficiency. At the same time, the results of these studies are limited to the investigated heat agents, as well as the relative roughness heights. To compare the results of experimental studies on heat transfer, a generalized mathematical expression is derived on the basis of the Lion equation. It is intended for determining the heat transfer coefficient of rough surfaces taking into account the influence of velocity distribution on temperature drop in the turbulent core of the flow and the dependence of thickness of the viscous sublayer on the flow mode. The height is determined as the key factor of roughness. Surface roughness is divided into technical and regular. Comparison of the obtained solution to the available experimental data on heat transfer in technically rough pipes showed a difference in the results up to 10%, while in pipes with a regular roughness the divergence did not exceed 14%.
The impact of hafnium addition on the properties of heat-resistant nickel alloy SM104
(2018) Kostin, A.; Gladchenko, D.; Костін, О. М.; Гладченко, Д. С.
Improvement of performance properties of heat-resistant nickel alloys remains a pending issue for alloys operating in conditions of high-temperature salt corrosion. Within this context our study examines the impact of hafnium on micro-structure and performance properties of standard heat-resistant nickel alloy CM104 which is widely used in construction of modern marine gas turbine engines. Through computational-analytical method it was determined that the optimal level of hafnium addition shall amount to 1,4 % of the alloy weight. The study included examination of the micro-structure of the alloys, their hardness, plasticity, short-term and long-term strength at a temperature of 900 ºС. It is shown first that hafnium contributes to the grinding of the alloy structure CМ104, it stretches the granules boundaries and increases the amount of volumetric fraction of the γ′- phase. Hafnium addition reduces hardness by 3…5 % on average and increases the plasticity of the alloy, it allows to increase resistance to high-temperature salt corrosion while maintaining short-term and long-term strength at 900 ºС. It will allow to improve the performance properties of heat-resistant nickel alloy CM104 and positively impact its bond-ability.
Implementation of the compensated operation mode of a synchronous generator with direct and transverse axis excitation
(2018) Podymaka, V. I.; Novogretskyi, S. N.; Подимака, В. І.; Новогрецький, С. М.
The article considers the possibility of putting a synchronous generator into a compensated mode by controlling excitation in the transverse axis. In this mode, the transverse armature reaction is completely compensated by the magnetizing force of the transverse excitation winding, the rotor torque angle is maintained at zero level, and the transverse component of the load current vector is its active component. It is shown that introduction of a positive feedback in the transverse excitation axis on the active component of the load current is sufficient in order to provide for this mode. At the same time, only proportional control of the generator’s armature voltage needs to be implemented for the direct excitation axis. Abandoning feedback on the reactive component of the armature current enables a more efficient damping of electromechanical oscillations in the system. As revealed by the study of the equation of dynamic equilibrium of the generator, oscillations of the rotor torque angle are damped at the use of the specified control method and at a loading angle below the critical value. The ratio of the magnetizing excitation forces and the transverse axis armature reaction has been analyzed, which allowed obtaining an analytical dependence of the feedback coefficient for the active component of the load current on the inductive resistance of the armature phase and geometric data of the generator.
Improvement of the mathematical model for spatial motion of a remotely operated underwater vehicle with technological equipment
(2018) Korytskyi, V. I.; Корицький, В. І.
Full-scale sea experiments of underwater vehicles and their automated control systems are an expensive and labor-intensive process. Moreover, execution of such experiments is always accompanied with the risk of damaging the components of an underwater vehicle or even injuring its crew. Thus, it is relevant to minimize the time of configuring automatic control systems of underwater vehicles through computer simulation. This paper considers advanced approaches to motion dynamics simulation for underwater vehicles with technological equipment. There is substantiated the necessity of developing a specialized mathematical model of a tethered remotely operated underwater vehicle with technological equipment. The proposed mathematical model accounts for an underwater vehicle that is organized according to the principle of separation of progressive motion of its hull and rotary motion of its technological equipment. The mathematical model of the rotary motion platform is designed; it considers the influence of disturbances arising from the technological equipment on the dynamics of its motion. The developed mathematical model will be used during the design and preliminary configuration of the automated control system for an underwater vehicle and its technological equipment.
The increasing of the thermal stability of the crushed substructure of steels
(2018) Dubovoy, A. M.; Makruha, T. O.; Chechel, O. V.; Дубовий, О. М.; Макруха, Т. О.; Чечель, О. В.
The influence of the combined deformation on the thermal stability of the poligonization substructure of the technically clean iron and steels are shown in the article. So, the purpose of the work is the increasing of the thermal stability of the poligonization substructure by combined deformation of iron, steel 20, 45, У8, 12Х13 and 40Х. The possibility of the increasing hardness on the maximum indexes are investigated and installed the optimum magnitude and species of the deformation and modes, namely temperature and time of the exposure, of the heat treatment. The possibility of the thermal stability of the poligonization substructure during prerecrystallization heat treatment of the Fe and carbon and alloyed steels by using combined deformation is established. The decreasing of the sizes of the regions of the coherent scattering of the values of the physical and mechanical properties, such as hardness, is proved. Indexes of the quantities of nanoscale substructure elements and angle of orientation of the subgrains are calculated by methods of the harmonic analysis. The combined deformation allows the using this method for machine parts and appliances. It was shown that pre-crystallization thermal treatment allows to form a substructure with nanosized elements of size 80 nm (steel 45) in a combination of deformed steels, and their quantity can reach 75 % of the total number of structural components with a maximum angle of divergence of subgrains 2.16º (technically pure iron).
The mathematical model of resonant frequency converter with pulse regulation
(2018) Pavlov, H. V.; Vinnychenko, I. L.; Павлов, Г. В.; Вінниченко, І. Л.
On the basis of the state variables method, the mathematical model of the resonant converter is constructed, within which the analytical dependences are obtained, which allow calculating the durations of the inter-commutation stages, the certain sequence of which provides the sinusoidal shape of the carrier pulses. The article aim is to study electromagnetic processes in the power section of the resonant frequency converter with pulse control and to obtain the analytical expressions for the durations of the inter-commutative stages of the converter operation. With the usage of the state variables method, the solutions of vector-matrix equations, which describe the processes in the power section of the resonant frequency converter, were obtained. That made possible to get the exact shape of the resonant voltage and current pulses and determine the durations of the inter-commutation stages, which provide their shape, characterized with the low THD. The phase characteristic of the converter operation cycle is constructed as well. The results of the research can be applied in the development of the pulse frequency converters control systems. The obtained analytical expressions allow computing the required switching moments of the converter power transistors.
Mathematical modeling of an autonomous uninhabited underwater vehicle dynamics with propeller in the rotary nozzle
(2018) Hrudinina, H. S.; Грудініна, Г. С.
In this paper, the research of hydrodynamic characteristics of a rotary screw column in the propulsion and steering complex (PSC) of an autonomous uninhabited underwater vehicle (AUV) is being carried out. These characteristics include: the change of the propeller thrust force and the force on the propeller shaft, during the change in the incident flow angle. To obtain the required characteristics, the method of mathematical modeling of the AUV plane motion in the Simulink system was applied. The improved mathematical model of the vehicle rectilinear motion was performed by supplementing its equations, which allows to simulate the operation of the PSC, “propeller–rotary nozzle”, in the downwash water flow. The propeller operation design in the guide nozzle in a direct and downwash water flow at the underwater vehicle different speeds is carried out. Vehicle speed and shaft speed graphs were obtained. The dependences of the change in propeller thrust force on incident flow angle are plotted for various underwater vehicle traverse speeds. The possibility of accounting for the significant nonlinear dependence of the propeller thrust force and the propeller shaft force on the incident flow angle is the scientific novelty. Practical significance of the work lies on the possibility of improving the AUV control quality by compensating for the changes in the propeller thrust force and force on the propeller shaft. It will be particularly relevant to use the obtained characteristics in the development of control systems for AUV trajectory motion.
Mathematical modeling of the automatic control system for an autonomous underwater vehicle as a group agent
(2018) Burunina, Z. Yu.; Aloba, L. T.; Hrudinina, H. S.; Буруніна, Ж. Ю.; Алоба, Л. Т.; Грудініна, Г. С.
A mathematical model of the automatic control system for an autonomous unmanned underwater vehicle operating as a group agent has been developed. The ACS was modeled in the MATLAB Simulink software. There has been carried out the simulation of the maneuvering motion of the AUUV, in which the device maintained at a safe distance from the given agent (object of the group) in the specified distance range: the adhesion mode, or the cohesion mode. The proposed control system contains two major control units: the distance control unit and the course control unit. For the implementation of the task, fuzzy controllers of the Mamdani-type were chosen, with defuzzification via the Center of Gravity method.
Method for determination of escort tugs main dimensions and characteristics at conceptual design stage
(2018) Yastreba, O. P.; Ястреба, А. П.
The paper is devoted to the development of a method for determination of main dimensions and characteristics of escort tugs designed for escorting tankers, gas carriers and other types of vessels with hazardous cargoes. Classification Societies require a reasonable preliminary calculation of the maximum holding force acting on a tug at the escort speed of 8 and 10 knots to be submitted in order to assign an escort class to a tug. The method for determination of hydrodynamic forces acting on the ASD escort tug during stationary escort operations is described. The method is based on processing of the data collected during towing tests of such tugs in the towing tank of the National University of Shipbuilding (NUOS). Processing of the experimental data allowed to obtain regression dependencies for stationary hydrodynamic forces acting on the escort tug on the drift angle ranging from 0 to 90 degrees. Towing tests were carried out on request of design organizations, and escort tug projects by TransShip Corporation were mainly used. These projects are TUG40, TUG50, TUG55, TUG55TA, TUG60, TUG60L, TUG60LA and TUG70 by E. D. Demidov, General Designer. The data obtained based on using the developed dependencies was compared with the data of full-scale tests of escort tugs of this series. Obtained dependences are included in the equations of motion of escort tug operational purpose, which is an integral part of the optimization problem of determination of escort tug main dimensions and characteristics. A method for solving the transcendental equations of the tug stationary motion during escort operations is proposed, similar to the method for solving an optimization problem. Using the obtained method for determination of hydrodynamic forces and the operational purpose, the problem of determination of escort tug main dimensions is defined with solution oriented to optimize dimensions based on escort tug serving a random stream of vessels arriving at the seaport.
Methods of improvement of the design and construction technology of composite docks
(2018) Kyrychenko, K. V.; Yahlytskyi, Yu. K.; Shchedrolosiev, O. V.; Кириченко, К. В.; Яглицкий, Ю. К.; Щедролосев, А. В.
The article renders the research based on the use of criteria for choosing the optimal design of a composite floating dock taking into account current standard requirements, which enable developing recommendations for the design and construction technology of the dock. There is substantiated the choice of the main parameters that make it possible to draw a generalized criterion for choosing the optimal designs of floating composite docks with account for the best practices of their construction and operation, as well as the results of experiments in the most difficult docking conditions. The system of criteria is used for controlling the mass and strength of dock structures, a set of technical and economic issues, reliability and ease of operation. A design of a composite floating dock with a reduced number of pontoon frames is proposed. There, the reinforcement aiding local strength is installed on the outside in the direction of the smallest span, and the reinforcement aiding general strength is installed inside the element. Special features of installing the frames in the top deck of the dock are described, and their absence in the concrete towers of the ribs of floor plates and beams is substantiated. The structural and technological diagrams of the constructive midship frame of a floating dock and the slipway for dock construction are presented. Their application allows reducing the material capacity and labour intensity of dock construction. The technological recommendations for reinforcement of bottom plates of the pontoon of a composite floating dock are rendered. The diagram of reinforcement of pontoon bottom plates in the area of maximum hydrostatic pressure is presented. It is shown that a protective layer of concrete on the working reinforcement provides for the joint operation of reinforcement with concrete at all stages of operation of the facility, as well as protection against aggressive external effects. Special features of the selection of a shipbuilding concrete targeted at the extreme conditions of operation of marine reinforced concrete facilities are listed. The influence of air-entraining and plasticizing agents in the concrete mixture is considered. They are used for the improvement of strength, impermeability, frost and corrosion resistance of concrete, reduction of water consumption, enhancement of workability and reduction of consumption of cement.

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