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El presente módulo se orienta en el desarrollo y modelamiento de geometrías para rotores de máquinas hidráulicas axiales basadas en el diseño asistido por computador o software CAD. En este sentido, es importante enfatizar dos puntos principales. Inicialmente, la relevancia de la temática tratada en este documento para los estudiantes de ingeniería, ya que el modelamiento de dichas geometrías son la plataforma que permite desarrollar y/u optimizar máquinas hidráulicas que aprovechen las energías renovables como la eólica o la corriente de los ríos, sin impactos relevantes en el medio ambiente. Esta temática cobra mayor importancia cuando el impacto se pude dar en las zonas no interconectadas al sistema de energía eléctrica nacional, las cuales, representaban para el año 2017, el 52% del territorio colombiano y una población aproximada de 1.900.000 habitantes (Superintendencia Delegada para Energía y Gas Combustible, 2017). Por otro lado, la literatura especializada en el modelamiento de componentes por medio de software CAD, trata temáticas generales que aportan para el desarrollo del estudiante, pero es una tarea compleja encontrar documentos que proporcionen información específica acerca del modelamiento de geometrías para máquinas hidráulicas axiales. Por lo tanto, este módulo procura favorecer la aplicación de conocimientos generales en temáticas puntuales de máquinas hidráulicas y acercar a los estudiantes a la solución de problemáticas de interés regional, nacional y global. This module focuses on the development and modeling of rotor geometries for axial hydraulic machines based on computer-aided design or CAD software. In this regard, it is important to emphasize two main points. Initially, the relevance of the topic covered in this document for engineering students, since the modeling of said geometries is the platform that allows the development and/or optimization of hydraulic machines that take advantage of renewable energies such as wind power or river currents. , without relevant impacts on the environment. This issue becomes more important when the impact could occur in areas not interconnected to the national electric power system, which, in 2017, represented 52% of the Colombian territory and a population of approximately 1,900,000 inhabitants (Delegated Superintendency for Energy and Fuel Gas, 2017). On the other hand, the specialized literature on the modeling of components by means of CAD software deals with general topics that contribute to the development of the student, but it is a complex task to find documents that provide specific information about the modeling of geometries for axial hydraulic machines. Therefore, this module seeks to promote the application of general knowledge in specific topics of hydraulic machines and bring students closer to the solution of problems of regional, national and global interest.

In the past few decades, the field of developing computer software systems has been actively developing, which in turn leads to competition in the software market. Qualified engineers working in the hydroturbine industry must be able to use a computer not only at the user level, but also at the programmer level in order to program modules for their own needs based on existing software systems. Recently, numerical simulation has become applicable to an ever wider class of flows, replacing experimental research methods. Certain numerical models are characterized by different areas of applicability and expenditures of computational resources. The paper provides an analytical review of modern CFD software systems. The advantages and disadvantages of these programs are analyzed in terms of building a three-dimensional model of the object of study, creating a computational grid, setting boundary conditions and visualizing the calculation results. The analysis and comparison of existing mathematical models that used to calculate the spatial flow in the flow path of hydraulic machines has been carried out. There are many different programs for solving hydrodynamic problems, some of the advanced commercial software systems are Ansys, SolidWorks Flow Simulation, Autodesk CFD. There are also open source softwareproducts. These automatic design systems make it possible not only to perform high-quality modeling of systems of various physical nature, but also to study the response of these systems to external influences in the form of distributions of pressures, temperatures, and velocities. The calculation algorithms in the programs are similar; the distinctive features of the programs can be evaluated according to the following criteria: grid generation, accuracy, reliability (convergence), calculation speed, model physics, system flexibility. The use of modern software packages for studying the hydrodynamic characteristics of the flow in hydraulic machines significantly reduces the time and material resources in comparison with physical modeling., In the past few decades, the field of developing computer software systems has been actively developing, which in turn leads to competition in the software market. Qualified engineers working in the hydroturbine industry must be able to use a computer not only at the user level, but also at the programmer level in order to program modules for their own needs based on existing software systems. Recently, numerical simulation has become applicable to an ever wider class of flows, replacing experimental research methods. Certain numerical models are characterized by different areas of applicability and expenditures of computational resources. The paper provides an analytical review of modern CFD software systems. The advantages and disadvantages of these programs are analyzed in terms of building a three-dimensional model of the object of study, creating a computational grid,setting boundary conditions and visualizing the calculation results. The analysis and comparison of existing mathematical models that used to calculate the spatial flow in the flow path of hydraulic machines has been carried out. There are many different programs for solving hydrodynamic problems, some of the advanced commercial software systems are Ansys, SolidWorks Flow Simulation, Autodesk CFD. There are also open source softwareproducts. These automatic design systems make it possible not only to perform high-quality modeling of systems of various physical nature, but also to study the response of these systems to external influences in the form of distributions of pressures, temperatures, and velocities. The calculation algorithms in the programs are similar; the distinctive features of the programs can be evaluated according to the following criteria: grid generation, accuracy, reliability (convergence), calculation speed, model physics, system flexibility. The use of modern software packages for studying the hydrodynamic characteristics of the flow in hydraulic machines significantly reduces the time and material resources in comparison with physical modeling.

El presente trabajo de grado tiene como propósito la construcción de un equipo de laboratorio que permita observar el fenómeno de cavitación presente en las bombas centrifugas, utilizando como instrumento la practicas básicas del diseño donde se hace un sondeo de empresas que fabriquen estos equipos y así establecer los requerimientos con los que debe cumplir el equipo a diseñar, siguiendo con el uso de ecuaciones de mecánica de fluidos para determinar el NPSH del sistema para realizar la selección de la bomba y comprobar con el número de cavitación que el sistema si va a cavitar, los resultados indican que el dispositivo efectivamente cavita un rango de caudal amplio, por tanto se concluye que el equipo cumple con los requerimientos establecidos, pero que puede llegar a ser mejor. The purpose of this graduate work is to construct a laboratory equipment that allows observing the cavitation phenomenon present in centrifugal pumps, using as an instrument the basic design practices where a survey of companies that manufacture these equipment is conducted and thus establish the requirements with which the equipment to be designed must comply, following the use of fluid mechanics equations to determine the NPSH of the system. to select the pump and check with the cavitation number that the system is going to cavitate, the results indicate that the device actually cavitates a wide range of flow rates, therefore it is concluded that the equipment meets the established requirements, but that it may be better. Ingeniero Mecánico Pregrado

Završni rad obrađuje hidrauličke strojeve odnosno zupčaste pumpe s unutarnjim ozubljenjem i motore koje se koriste u hidrauličkim sustavima. Osnovna podjela hidrauličkih pumpi navedena je u tablici konstrukcijske podjele te su prikazani simboli hidrauličkih pumpi. Temeljito je opisana konstrukcija zupčaste pumpe s unutrašnjim ozubljenjem, princip rada, sastavni dijelovi i njihove funkcije kao i dijagram veličina zupčastih pumpi u Bosh izvedbi. Također je navedena Duo pumpa kod koje dva zupčanika imaju različit pomak za razliku od uobičajene zupčaste pumpe s unutrašnjim ozubljenjem. Kao hidraulički motori s unutrašnjim ozubljenjem su navedeni motori s jednim smjerom vrtnje i motori s dva smjera vrtnje te je opisan georotor motor., The final work deals with hydraulic machines, i.e. gear pumps with internal gearing and motors used in hydraulic systems. The basic division of hydraulic pumps is listed in the structural division table and the symbols of hydraulic pumps are shown. The construction of the gear pump with internal gearing, the principle of operation, the components and their functions, as well as the diagram of the sizes of the gear pumps in the Bosch version are thoroughly described. Also listed is the Duo pump, where the two gears have different offsets, unlike the usual gear pump with internal gearing. As hydraulic motors with internal gearing, motors with one direction of rotation and motors with two directions of rotation are listed, and a georotor motor is described.

At present, the development of software packages for calculating computational fluid dynamics problems has reached a high level of efficiency, accuracy and flexibility, with their help it is possible to solve the most diverse and complex problems. All modern software packages for computational fluid dynamics solve the problems of continuum mechanics using models based on the Navier-Stokes equations. These models are based on three conservation equations: conservation of mass, conservation of momentum and conservation of energy. A numerical simulation of the spatial flow of a high-head radial-axial hydraulic turbine Fr 310 was carried out for two variants of the flow path – with an runner with 15 blades (modification 1) and with 17 blades (modification 2), using the OpenFOAM software package. The OpenFOAM software package is one of the most used products designed to solve fluid dynamics problems and is distributed under a free GPL license (General Purpose License). The process of solving the set hydrodynamic problems using the CFD (Computational fluid dynamics) software package includes the following stages: creating a three-dimensional model of the object under consideration using a computer-aided design system; construction of a computational grid with the required parameters; selection of a mathematical model that most accurately describes the working process in the flow parts of hydraulic machines; selection of a suitable turbulence model; setting boundary conditions. A visualization of the results of a numerical study of two modifications of the Fr 310-V-100 hydraulic turbine is presented. A method for calculating hydraulic losses in the flow path of a hydraulic turbine is presented. The analysis of the results of numerical simulation was performed. This analysis showed that the modification of a hydraulic turbine with a runner with 15 blades is better in terms of efficiency than the modification with 17 blades. Comparison of the two modifications was carried out exceptionally by the values of the hydraulic efficiency of the hydraulic turbine.

The educational guide is intended to prepare international citizens for study at universities and is designed to help them in choosing a future specialty. The manual includes: brief information that allows students to get a general idea of the structure of our university, areas of study and specialties, opportunities for scientific activity, as well as discoveries, start-ups and inventions of scientists of NTU "KhPI". The manual is intended for students and teachers of all forms of pre-university training.

The paper critically reviews the current state of the art in flow inside sidewall gaps of hydraulic pumps and turbines. It describes the consequences of the presence of this type of flow in turbomachinery and then relates it to other physical phenomena that determine the behavior, operating characteristics, and overall performance of the machine. Despite the small dimensions of the rotor-stator spaces, the flow in these regions can significantly affect the overall flow field and, consequently, efficiency. The circulation of the fluid inside the gaps and secondary flow that is caused by rotating elements influences the disk friction losses, which is of great importance, especially in the case of low specific speed pumps and turbines. The flow pattern affects the pressure distribution inside a machine and, thus, generates axial thrust. The presence of secondary flow also significantly changes the rotordynamics and can bring about undesirable vibrations and acoustics issues. This article aims to review and summarize the studies that were conducted on the mentioned phenomena. Experimental and numerical studies are both taken into consideration. It proposes some requirements for prospective research in order to fill current gaps in the literature and reveals the upcoming challenges in the design of hydraulic machines.

In connection with the growing trend of using continuously variable hydro volume-mechanical transmissions (HVMT) on vehicles, not only for agricultural purposes, but also for road-building, logging and special-purpose vehicles, the issue of installing this type of transmission on a domestic KrAZ vehicle is becoming more acute and promising.The most important part of the continuously variable HVMT is the hydrostatic transmission (HT), which provides a smooth change in the transmission ratio and consists of two positive displacement hydraulic machines: a hydraulic pump and a hydraulic motor. Determination of HT indicators when using hydraulic machines with different displacement volumes is a mandatory step, without which further work in the direction of using continuously variable HVMTs on special-purpose trucks is impossible.The article deals with the theoretical determination of HVMT indicators when using axial piston hydraulic machines of different working volume with an inclined disk in the HT. The influence of changes in the working volume on the main indicators of continuously variable HVMT is investigated, such as the efficiency (efficiency) of the HT and HVMT as a whole, the operating pressure drop, the engine power when driving in full-flow, in working and transport modes.As an object of research, we used a two-line HVMT No. 1, developed by the Department of Automobile and Tractor Engineering of the National Technical University "Kharkov Polytechnic Institute", a KrAZ 6233M automobile and axial piston hydraulic machines with a working volume of 89 cm3, 118 cm3 produced by the joint-stock company Gidrosila and 150 cm3 produced by the Italian company Bondioli & Pavesi. Recommendations on a possible stepless HVMT for the KrAZ 6233M vehicle are presented., У зв’язку з ростом тенденції використання безступінчастих гідрооб’ємно-механічних трансмісій (ГОМТ) на транспортних засобах не тільки сільськогосподарського призначення, а й дорожньо-будівельних, лісозаготівельних та на машинах спеціального призначення, питання щодо встановлення такого типу трансмісії на вітчизняні автомобілі КрАЗ стає все гостріше та перспективніше. Найважливійшою частиною безступінчастих ГОМТ є гідрооб’ємна передача (ГОП), яка забезпечує плавну зміну передаточного відношення трансмісії і складається з двох гідромашин об’ємного типу: гідронасоса та гідромотора. Визначення показників ГОП при використанні гідромашин з різним робочим об’ємом є обов’язковим кроком, без якого неможлива подальша робота в напрямку використання безступінчатих ГОМТ на вантажних автомобілях спеціального призначення. У статті йдеться про теоретичне визначення показників ГОМТ при використанні в ГОП аксіально-поршневих гідромашин різного робочого об'єму з похилим диском. Досліджується вплив зміни робочого об'єму на основні показники безступінчатих ГОМТ, такі як коефіцієнт корисної дії (ККД) ГОП і ГОМТ в цілому, перепад робочого тиску, потужність двигуна при русі в повнопотоковому, в робочому і в транспортному режимах. Як об'єкт дослідження використана двухпоточная ГОМТ №1, розроблена кафедрою «Автомобіле-і тракторобудування» Національного технічного університету «Харківський політехнічний інститут», автомобіль КрАЗ 6233М і аксіально-поршневі гідромашини робочим об'ємом 89 см3, 118 см3 виробництва акціонерного товариства «Гідросила» та 150 см3 виробництва італійської фірми Bondioli & Pavesi. Подано рекомендації щодо можливої безступінчастої ГОМТ для автомобіля типу КрАЗ 6233М.

В даний час розвиток пакетів прикладних програм для розрахунку задач обчислювальної гідроаеродинаміки досяг високого рівня ефективності, точності і гнучкості, з їх допомогою можна вирішувати самі різноманітні та складні задачі. Всі сучасні пакети програм обчислювальної гідроаеродинаміки вирішують завдання механіки суцільного середовища, використовуючи моделі, побудовані на основі рівнянь Нав'є-Стокса. В основу цих моделей входять три рівняння збереження: збереження маси, збереження імпульсу і збереження енергії. Було проведено чисельне моделювання просторового потоку високонапірної радіально-осьової гідротурбіни РО 310 для двох варіантів проточної частини – с робочим колесом, що має 15 лопатей (модифікація 1) та з 17 лопатями (модифікація 2), з використанням пакета прикладних програм OpenFOAM. Програмний комплекс OpenFOAM є одним з найбільш використовуваних продуктів, призначених для вирішення завдань гідродинаміки, що розповсюджуються за вільною ліцензією GPL (General Purpose License). Процес вирішення поставлених гідродинамічних задач за допомогою програмного комплексу CFD (Computational fluid dynamics) включає в себе наступні етапи: створення тривимірної моделі розглянутого об’єкта за допомогою системи автоматичного проектування; побудова розрахункової сітки з необхідними параметрами; вибір математичної моделі, яка найточніше описує робочий процес в проточних частинах гідромашин; вибір відповідної моделі турбулентності; завдання граничних умов. Приведено візуалізацію результатів чисельного дослідження двох модифікацій гідротурбіни РО 310-В100. Представлено методику розрахунку гідравлічних втрат в проточній частині гідротурбіни. Виконано аналіз результатів чисельного моделювання. Даний аналіз показав, що модифікація гідротурбіни з робочим колесом, що має 15 лопатей, краща по значенню ККД, ніж модифікація з 17 лопатями. Порівняння двох модифікацій проводилося виключно по значенням гідравлічного ККД гідротурбіни. At present, the development of software packages for calculating computational fluid dynamics problems has reached a high level of efficiency, accuracy and flexibility, with their help it is possible to solve the most diverse and complex problems. All modern software packages for computational fluid dynamics solve the problems of continuum mechanics using models based on the Navier-Stokes equations. These models are based on three conservation equations: conservation of mass, conservation of momentum and conservation of energy. A numerical simulation of the spatial flow of a high-pressure radial-axial hydraulic turbine RO 310 was carried out for two variants of the flow path – with an runner with 15 blades (modification 1) and with 17 blades (modification 2), using the OpenFOAM software package. The OpenFOAM software package is one of the most used products designed to solve fluid dynamics problems and is distributed under a free GPL license (General Purpose License). The process of solving the set hydrodynamic problems using the CFD (Computational fluid dynamics) software package includes the following stages: creating a three-dimensional model of the object under consideration using a computer-aided design system; construction of a computational grid with the required parameters; selection of a mathematical model that most accurately describes the working process in the flow parts of hydraulic machines; selection of a suitable turbulence model; setting boundary conditions. A visualization of the results of a numerical study of two modifications of the RO 310-V100 hydraulic turbine is presented. A method for calculating hydraulic losses in the flow path of a hydraulic turbine is presented. The analysis of the results of numerical simulation was performed. This analysis showed that the modification of a hydraulic turbine with an runner with 15 blades is better in terms of efficiency than the modification with 17 blades. Comparison of the two modifications was carried out solely by the values of the hydraulic efficiency of the hydraulic turbine.

The paper reviews recent research and development activities in the field of hydropower technology. It covers emerging and advanced technologies to mitigate flow instabilities (active and passive approach) as well as emerging magneto-rheological control techniques. Recent research findings on flow instabilities are also presented, especially concerning fluid-structure interaction and transient operating conditions. As a great number of the existing large-scale hydroelectric facilities were constructed decades ago using technologies that are now considered obsolete, technologies to achieve the digitalisation of hydropower are also analysed. Advances in the electro-mechanical components and generator design are presented; their potential role to adapt hydropower to the current operating conditions is also highlighted. The text explores current efforts to advance hydropower operation, mainly in terms of European projects. It provides a detailed overview of the recent efforts to increase the operational range of hydraulic turbines in order to reach exceptional levels of flexibility, a topic of several recent research projects. Variable speed hydropower generation and its application in pumped storage power plants are presented in detail. Moreover, revolutionary concepts for hydroelectric energy storage are also presented with the analysis focusing on underwater hydro storage and hydropower's hybridisation with fast energy storage systems. Efforts to minimise hydropower's environmental footprint are also presented via the utilisation of small-scale and fish-friendly installations.

The gerotor pump has many advantages over other hydraulic pumps, such as high reliability, compactness, lower noise in running conditions etc. Considering the increasingly stringent regulations in the field of environmental protection, one of the main goals in the industrial applications of gerotors is to improve their design by using light materials and optimize their performance. This paper will give an overview of modern research that focuses on improving the performance of gerotor pumps. A joint publication of three university centers, namely of Wroclaw, Terrassa and Kragujevac, presents their original approaches to the problem of designing gerotor and orbital systems. The presentations have been prepared in separate parts, but according to similar rules. The first part of the paper focuses on meshing between internal and external gear of gerotor. Analysis for both cases, moved axis and fixed axis, will be provided in accordance to their working characteristics and their application. The second part of the paper provides the design of a gerotor pump strikes a balance between volumetric efficiency, manufacturability and mechanical efficiency. The third part of the paper defines the methodology for selecting the best combination of geometric form parameters of the trochoidal gearing in relation to the reduction of contact stresses and improving other characteristics of the pump. All three parts provide manufacturing and application review in the fluid power machines. Paper concludes with presented theoretical and experimental review of the authors and their practice achievements.

В последние годы был достигнут существенный прогресс в создании методов моделирования и расчета течений жидкости, которые позволяют выполнять расчет со столь высокой достоверностью полученных результатов, необходимый объем эксперимента во многих случаях сводится к минимуму. Все современные пакеты программ решают задачи механики сплошной среды, используя модели, построенные на основе уравнений Навье-Стокса. В основу этих моделей входят три уравнения сохранения: сохранения массы, сохранения импульса и сохранения энергии. Программный комплекс CFD предназначен для моделирования трехмерных течений жидкости и газа в технических и природных объектах, а также визуализации этих течений методами компьютерной графики. Были рассмотрены варианты проведения гидродинамических расчетов в различных типах гидравлических машинах с использованием пакета программ CFD. Процесс решения поставленных гидродинамических задач с помощью программного комплекса CFD включает в себя следующие этапы: создание трехмерной модели рассматриваемого объекта с помощью системы автоматического проектирования; построение расчетной сетки с необходимыми параметрами; выбор математической модели, наиболее точно описывающей рабочий процесс в проточных частях гидромашин; выбор подходящей модели турбулентности; задание граничных условий. Проведены численные исследования пространственного течения жидкости в проточных частях гидравлических машин на примере капсульной гидротурбины, обратимой гидравлической машины в насосном и турбинном режимах работы, радиально-осевой гидротурбины. Представлены результаты расчетов, а именно визуализация потока в виде полей распределения скоростей и давления. Проведен анализ сходимости результатов численного исследования с экспериментальными данными на основе сравнения значений гидравлического коэффициента полезного действия рассматриваемых гидромашин. Over the last years, significant progress has been made in creating methods for modelling and calculating fluid flows, which allow performing calculations with high reliability of the obtained results; the necessary amount of experiment in many cases is reduced to a minimum. All modern software packages solve the problems of mechanics of continuum medium using models, which are built based on the Navier-Stokes equations. These models are based on three conservation equations: mass conservation, momentum conservation, and energy conservation. The CFD software package is designed to simulate three-dimensional fluid and gas flows in technical and natural objects and visualize these flows using computer graphics methods. The variants of conducting hydrodynamic calculations in different types of hydraulic machines using the CFD software package were considered. The process of solving the hydrodynamic tasks using the CFD software package includes the following steps: creatinga three-dimensional model of the considering object using an automated design system; construction of the calculation grid with the required parameters; selection of the mathematical model that most accurately describes the operating process in the water passage of hydraulic machines; selection of a suitable turbulence model; setting boundary conditions. Numerical studies of the spatial flow of fluid in the water passages of hydraulic machines have been carried out. The water passages of the capsular turbine, the reversible hydraulic machine in pumping and turbine operating modes, and the radial-axial hydraulic turbine were considered. The results of the calculations were presented in the form of the visualization of velocity and pressure distribution fields of the flow. The analysis of the convergence of the results of numerical studies with experimental data were performed based on a comparison of the values of the hydraulic efficiency of the considered hydraulic machines.

The development of renewable and intermittent power generation creates incentives for the development of both energy storage solutions and more flexible power generation assets. Pumped-storage hydropower (PSH) is the most established and mature energy storage technology, but recent developments in power electronics have created a renewed interest by providing PSH units with a variable-speed feature, thereby increasing their flexibility. This paper reviews technical considerations related to variable-speed pumped-storage hydropower (PSH) in link with the provision of primary frequency control, also referred to as frequency containment reserves (FCRs). Based on the detailed characteristics of a scale model pump-turbine, the variable- speed operation ranges in pump and turbine modes are precisely assessed and the implications for the provision of FCRs are highlighted. Modelling and control for power system studies are discussed, both for fixed- and variable-speed machines and simulation results are provided to illustrate the high dynamic capabilities of variable-speed PSH.

В статье приведены сведения о конструкции колтюбинговых установок разных производителей, которые применяются при капитальном ремонте скважин. Показана типовая схема наземной колтюбинговой установки и наиболее сложные и ответственные узлы и механизмы, входящие в её состав. Приведены основные особенности применения, а также преимущества применяемых технологий с использованием безмуфтовых длинномерных труб. Основных видов ремонтных работ, выполняемых с помощью колтюбинговых установок,насчитывается более десяти. Показана разработанная авторами технология удаления плотных песчано-глинистых пробок с аномально низким пластовым давлением (АНПД). Оговорены особенности повышения экономической эффективности при использовании колтюбинговых установок. This article provides information about the design of coiled tubing units from different manufacturers that are used in the workover. The typical circuit ground coiled tubing unit and the most complex and critical components and mechanisms that are included in its compositionare represented. The main features of the application, as well as the benefits of the technologies used with flush-joint pipe, are shown. The major types of repair work carried out by coiled tubing unitsare more than ten. The technology developed by the authors of the removal of dense sand and clay tubes with abnormally low formation pressure (ALFP) is shown. Specified features to increase economic efficiency in the use of coiled tubing units.

Die vorliegende Arbeit besch��ftigt sich prim��r mit der Bestimmung des rotordynamischen Verhaltens von Rotoren, beziehungsweise hydraulischen Maschinens��tzen. Das ��bertragungsmatrizenverfahren dient dabei als grundlegendes Konzept. Hauptziel des Verfahrens ist die Ermittlung von Eigenkreisfrequenzen und Eigenformen bei Biege- und Torsionsschwingungen im eingeschwungenen Zustand. Weitere Ergebnisse sind Absenkung, Neigung, Moment und Querkraft am Anfang und Ende jeden Elementes. Die Methode der ��bertragungsmatrizen zerlegt das System in Elemente, die anschlie��end mit Matrizen beschrieben werden k��nnen. Hergeleitet wurden Matrizen f��r ein masseloses und massebehaftetes Balkenelement mit konstanter Steifigkeit. F��r Biegeschwingungen wurde eine Massenmatrix abgeleitet, die Massen mit Exzentrizit��t und Kreiseleffekten, sowie anisotroper Lagerung ber��cksichtigt. Im Fall von Torsionsschwingungen wurde eine Massenmatrix, die Masse beachtet, erstellt. Das programmierte Simulationsprogramm HydroVib beinhaltet das ��bertragungsmatrizenverfahren. Daher k��nnen Eigenkreisfrequenzen und Eigenformen von beliebig langen rotierenden Maschinens��tzen ohne D��mpfung berechnet werden. Weiter k��nnen Resonanzkurven, Schwingungsformen und Orbits von Systemen mit D��mpfung ermittelt werden. Ein System unter Kreiseleinfluss bewirkt, dass die Eigenkreisformen nicht konstant sind. Im Campbell Diagramm k��nnen die Eigenkreisfrequenzkurven berechnet werden., The following thesis primary deals with determination of rotordynamic behaviour of rotors or rather hydraulic machine sets. The whole concept is based on the transfer matrix method. Principal purpose is to determine eigenfrequencies and eigenmodes of bending and torsional vibrations at steady-state condition. Further solutions are deflection, deviation, moment and shearing force at the beginning and ending of every element. The transfer matrix method disassemble the whole system by elements. Those elements can be described by matrices. A matrix was derived from a beam element with and without mass. For bending vibration, a matrix which considered excentric mass with gyro effect and anisotropic bearings, was derived. In case of torsional vibration a matrix, which consideres the mass, was derived. The programmed simulation program HydroVib includes the transfer matrix method. So eigenfrequencies and eigenmodes of machine sets with any length without damping, can be calculated. Further resonance curves, modes of vibrations and orbits of systems with damping can be detected. For gyro effect a Campbell digramm can be generated.

V svetu postajajo hidravlične naprave vse bolj nepogrešljiv člen pri delu. Potrebno je brezhibno delovanje celotne delovne enote, ki združuje hidravlično opremo nekega stroja za njeno popolno koriščenje. Različne analize okvar na hidravličnih napravah kažejo, kako pomembno je pravilno vzdrževanje hidravličnih naprav. Velik problem pri delovanju le-teh povzroča zrak v hidravličnem olju, katero se kot tlačna tekočina največkrat uporablja v hidravličnih napravah. Prisotnost zraka v olju pri določenih pogojih lahko povzroča veliko nezaželenih lastnosti, kot so npr. poslabšanje mazalne lastnosti olja, oksidacijo olja, pospešuje korozijo kovinskih delov, itd. V skladu s tem je za razumevanje delovanja hidravličnih naprav potrebno dobro poznavanje fizikalnih lastnosti in zakonitosti, kako in zakaj zrak pride v hidravlično napravo in v olje, ter kako ga iz njega odstraniti. Diplomsko delo obsega opis problema, kako pride zrak v hidravlični sistem ter dokaz le-tega na modelu rezervoarja in na realnem industrijskem agregatu.. Diplomsko delo obsega tudi študijo možnosti na kaj vse zrak v sistemu vpliva, ter prikaz poteka merjenje stisljivosti različnih mineralnih olj brez in z vključki zraka. Hydraulic machines have become an indispensable link at work. It is important to keep flawless operation of the whole work unit that combines hydraulic equipment of a machine for its perfect use. Different analysis of damages on the machines show how important it is to properly maintain hydraulic machines. Air in hydraulic oil, which is used as pressure liquid, can cause large problems in functioning. The presence of oil in certain circumstances can cause many unwanted properties, such as deterioration of oil lubricity, oil oxidation, it increases the corrosion of metal parts, etc. According to this, if we want to understand how hydraulic machines work, it is crucial to have good knowledge about physical properties of how and why air gets into a hydraulic machine and into oil, and how to remove it. The thesis contains description of the problem of air entering into the hydraulic system, and also evidence based on a reservoir model and on a real industrial aggregate. The thesis also includes a study of possibilities about which impacts air has in the system, and a presentation of measuring the compressibility of various mineral oils with and without air.

© 2014, Allerton Press, Inc. The paper presents a definition of hydroerosive wear that occurs in hydraulic machines due to the presence of water or air in a fluid that was used in the mathematical model. As is indicated by the complex of equations obtained by conversions, the relationship between the velocity of the hydroerosive wear of piston couples and the presence of water in fluid is exponential. In addition, the wear velocity is determined to be directly proportional to the presence of air inside of the hydraulic system and inversely proportional to the pressure achieved by the pump.

Гідравлічні машини є основним компонентом гідроприводів. Це енергетична машина, задача якої перетворювати механічну енергію твердого тіла в механічну енергію рідини.

© 2014, Allerton Press, Inc. The paper presents a definition of hydroerosive wear, which occurs in hydraulic machines due to water/air presence in fluid, obtained from a mathematical model. The model includes fatigue processes related to the influence of hydraulic water droplets inside of air bubbles in the surface layer of metal, as well as a sharp increase in temperature caused by adiabatic compression in the piston chamber of a hydraulic machine.

Ingeniería técnica de Telecomunicación

Doktorska disertacija obravnava vpliv delcev na obratovalne karakteristike hidravličnih strojev. Zastavljen problem je določiti vpliv delcev na razvoj kavitacije in hrupa, ter zapisati matematično fizikalni model vključitve disperzne faze delcev na razvoj kavitacije v programskem okolju CFD. V delu je izdelana podrobnejša analiza disperznih delcev v rečni vodi, ter njihov vpliv na obratovanje treh različnih hidroelektrarn. V eksperimentalnih raziskavah je bila največja pozornost namenjena določitvi odvisnosti masne koncentracije delcev na razvoj kavitacije in hrupa. Poglobljene raziskave so potekale na določitvi vpliva delcev na začetno kavitacijsko število. Eksperimentalne meritve so nam bile vodilo za potrditev rezultatov numeričnega modeliranja. V CFD smo kapljevito in parno fazo zajeli kot zvezdno fazo. Delce v večfaznem toku smo opredelili kot disperzno fazo. Numerično modeliranje kapljevite, parne in disperzne faze je potekalo z Euler-Euler pristopom, na osnovi Navier Stokesovih enačb. Uporabili smo kavitacijski model zasnovan na podlagi Rayleigh-Plessetove enačbe. Zapisali smo fizikalno matematični model vpliva delcev na razvoj kavitacije, v katerega smo vključili disperzno fazo. Posebej smo se osredotočili na strižno viskoznost trdnine. S parametričnim pristopom smo definirali in zapisali empirični nastavek, v odvisnosti od masne koncentracije delcev. Rezultate numeričnega modeliranja večfaznega toka, smo primerjali z eksperimentalnimi rezultati. This doctoral dissertation examines the impact of particles on the operating characteristics of hydraulic machines. The main goal was to determine the impact of particles on the development of cavitation and noise, and to establish a mathematical physical model integrating the effect of disperse phase particles on the development of cavitation within the CFD software environment. In this work a more detailed analysis of dispersed particles in the river water and their impact on the operation of three different hydroelectric power plants was made. In the experimental studies the focus was made on determining the dependence the development of cavitation and noise on mass concentration of particles in the fluid. More detailed research was conducted on determining the impact of particles on the initial cavitation number. Experimental measurements served to confirm results of numerical modelling. In CFD, we used liquid and vapour phase as continuous phases. The particles in a multiphase flow were defined as the dispersed phase. Numerical modelling of liquid, vapour and dispersed phase was conducted with the Euler-Euler approach, based on the Navier Stokes equations. We used a cavitation model based on Rayleigh-Plesset equation. We developed mathematical physical model of particles’ impact on the development of cavitation, in which the dispersed phase was included. We particularly focused on modelling the shear viscosity of the solids. With the parametric approach we described and developed an empirical formula implementing the mass concentration of particles. The results of the numerical modelling of multiphase flow were compared with the experimental results.

У бібліографічному покажчику зібрані матеріали про життєвий шлях, наукову діяльність заслуженого професора Сумського державного університету, академіка Міжнародної інженерної академії, Інженерної академії України, заслуженого працівника освіти України Ігоря Олександровича Ковальова. Покажчик виходить до 70-річчя від дня народження. При цитуванні документа, використовуйте посилання http://essuir.sumdu.edu.ua/handle/123456789/23995