O proposito deste trabalho é apresentar uma metodologia para projeto de uma turbina axial para micro aproveitamentos hidráulicos com ênfase no projeto das geometrias do rotor e distribuidor, incluindo os resultados analíticos e numéricos através do método dos painéis. Comparações do projeto analítico com testes de campo são também apresentadas. A metodologia analítica utilizada foi a teoria do escoamento não-viscoso de Wenig que avalia os fatores de interferência para modelar o quanto as características de sustentação e arrasto de uma cascata de perfis são relacionadas com as de um perfil isolado. Foi verificado que a teoria de Wenig fornece uma boa previsão do fator de interferência se o ângulo de ataque for relativamente baixo e a espessura das pás for relativamente pequena quando comparada com a distância entre as pás. A metodologia numérica usando o método de vorticidade superficial proposto por Martensen para uma cascata de perfis e para um perfil isolado foi utilizada para se ter uma comparação com os coeficientes analíticos de sustentação e arrasto. Testes de campo foram realizados em um protótipo de 20 kW de acordo com a norma IEC-60041 e sua comparação com o método analítico e por consequência o método numérico validou o método empregado para confecção das pás do rotor e distribuidor. / The purpose of this work is to present a methodology to design a small axial hydraulic turbine with emphasis on the project of the profiles of the runner and wicket gate, including both analytical and numerical results from a cascade panel method. Comparisons with field test measurements of a prototype are also presented. The analytical methodology used is the Wenigs inviscid flow theory which requires the evaluation of interference factors to model how lift and drag characteristics of the turbine cascade of blades are related to those of a single isolated airfoil. It is found that the Wenigs theory provides a reasonable prediction of the lift interference factor if both the angle of attack is relatively low and the thickness of the blades is relatively small when compared to the distance between the blades. The numerical methodology that relies the Hess and Smiths 2-D panel method for a cascade of blades and for an isolated airfoil was used in order to have a comparison with the analytical lift and drag. Prototype field test measurements of the turbine power output, in agreement with IEC-60041 standards, were carried out to evaluate the results using the analytical and numerical methods.

Um dos grandes desafios enfrentados pelos fabricantes de turbinas hidráulicas é prevenir o aparecimento de vibrações induzidas pelo escoamento nas travessas do pré-distribuidor e pás do rotor. Considerando apenas as travessas, e atribuídos a tais vibrações, foram relatados 28 casos de trincas ou ruídos anormais nas últimas décadas, que acarretaram enormes prejuízos associados a reparos, atrasos e perda de geração. O estado da arte na prevenção destes problemas baseia-se na utilização de sofisticados, e caros, programas comerciais de dinâmica dos fluidos computacional para o cálculo transiente do fenômeno. Este trabalho faz uma ampla revisão bibliográfica e levantamento de eventos de trincas ou ruídos ocorridos em travessas nos últimos 50 anos. Propõe, então, um enfoque alternativo, baseado exclusivamente em ferramentas de código aberto. A partir de hipóteses simplificadoras devidamente justificadas, o problema é formulado matematicamente de forma bidimensional, no plano da seção transversal da travessa, levando em conta a interação fluido-estrutura. Nesta estratégia, as equações de Navier-Stokes são resolvidas pelo método dos elementos finitos por meio da biblioteca gratuita oomph-lib. Um código especial em C++ é desenvolvido para o problema de interação fluido-estrutura, no qual o fenômeno de turbulência é levado em consideração por meio de um algoritmo baseado no modelo de Baldwin-Lomax. O método proposto é validado por meio da comparação dos resultados obtidos com referências e medições disponíveis na literatura, que tratam de problemas de barras retangulares suportadas elasticamente. O trabalho finaliza com a aplicação do método a um estudo de caso envolvendo uma travessa particular. / One of the biggest challenges for hydraulic turbine manufacturers is to prevent vortex-induced vibration on the stay vanes and runner blades. Only regarding stay vanes, 28 cases of cracks or unusual noises attributed to such vibrations were reported in the past decades leading to huge costs due to repair, delays and lack of generation. The state of the art today is to use powerful and expensive commercial computational fluid dynamics software to address the required transient phenomena. The present work carries out a comprehensive survey on occurred events in stay vanes during the last 50 years. Then, an alternative approach, based only on free open-source tools, is proposed. From due justified simplifying assumptions, the problem is formulated two-dimensionally, in the stay vane cross section plane, taking the fluid-structure interaction into account. In such a strategy, the Navier-Stokes equations are solved using oomph-lib, an object-oriented, finite-element library. A special C++ computational code is developed to deal with the fluid-structure interaction problem, in which turbulence is considered through a special algorithm, based on the Baldwin-Lomax model. The proposed method is validated through comparisons with an aerodynamics benchmark and an experimental measurement of oscillating rectangular bars both available in the literature. The method is finally applied to a case study of a particular stay vane. Keywords: Hydraulic turbine. Fluid-structure interaction. Vortex-induced vibration.

Um dos grandes desafios enfrentados pelos fabricantes de turbinas hidráulicas é prevenir o aparecimento de vibrações induzidas pelo escoamento nas travessas do pré-distribuidor e pás do rotor. Considerando apenas as travessas, e atribuídos a tais vibrações, foram relatados 28 casos de trincas ou ruídos anormais nas últimas décadas, que acarretaram enormes prejuízos associados a reparos, atrasos e perda de geração. O estado da arte na prevenção destes problemas baseia-se na utilização de sofisticados, e caros, programas comerciais de dinâmica dos fluidos computacional para o cálculo transiente do fenômeno. Este trabalho faz uma ampla revisão bibliográfica e levantamento de eventos de trincas ou ruídos ocorridos em travessas nos últimos 50 anos. Propõe, então, um enfoque alternativo, baseado exclusivamente em ferramentas de código aberto. A partir de hipóteses simplificadoras devidamente justificadas, o problema é formulado matematicamente de forma bidimensional, no plano da seção transversal da travessa, levando em conta a interação fluido-estrutura. Nesta estratégia, as equações de Navier-Stokes são resolvidas pelo método dos elementos finitos por meio da biblioteca gratuita oomph-lib. Um código especial em C++ é desenvolvido para o problema de interação fluido-estrutura, no qual o fenômeno de turbulência é levado em consideração por meio de um algoritmo baseado no modelo de Baldwin-Lomax. O método proposto é validado por meio da comparação dos resultados obtidos com referências e medições disponíveis na literatura, que tratam de problemas de barras retangulares suportadas elasticamente. O trabalho finaliza com a aplicação do método a um estudo de caso envolvendo uma travessa particular. / One of the biggest challenges for hydraulic turbine manufacturers is to prevent vortex-induced vibration on the stay vanes and runner blades. Only regarding stay vanes, 28 cases of cracks or unusual noises attributed to such vibrations were reported in the past decades leading to huge costs due to repair, delays and lack of generation. The state of the art today is to use powerful and expensive commercial computational fluid dynamics software to address the required transient phenomena. The present work carries out a comprehensive survey on occurred events in stay vanes during the last 50 years. Then, an alternative approach, based only on free open-source tools, is proposed. From due justified simplifying assumptions, the problem is formulated two-dimensionally, in the stay vane cross section plane, taking the fluid-structure interaction into account. In such a strategy, the Navier-Stokes equations are solved using oomph-lib, an object-oriented, finite-element library. A special C++ computational code is developed to deal with the fluid-structure interaction problem, in which turbulence is considered through a special algorithm, based on the Baldwin-Lomax model. The proposed method is validated through comparisons with an aerodynamics benchmark and an experimental measurement of oscillating rectangular bars both available in the literature. The method is finally applied to a case study of a particular stay vane. Keywords: Hydraulic turbine. Fluid-structure interaction. Vortex-induced vibration.

O proposito deste trabalho é apresentar uma metodologia para projeto de uma turbina axial para micro aproveitamentos hidráulicos com ênfase no projeto das geometrias do rotor e distribuidor, incluindo os resultados analíticos e numéricos através do método dos painéis. Comparações do projeto analítico com testes de campo são também apresentadas. A metodologia analítica utilizada foi a teoria do escoamento não-viscoso de Wenig que avalia os fatores de interferência para modelar o quanto as características de sustentação e arrasto de uma cascata de perfis são relacionadas com as de um perfil isolado. Foi verificado que a teoria de Wenig fornece uma boa previsão do fator de interferência se o ângulo de ataque for relativamente baixo e a espessura das pás for relativamente pequena quando comparada com a distância entre as pás. A metodologia numérica usando o método de vorticidade superficial proposto por Martensen para uma cascata de perfis e para um perfil isolado foi utilizada para se ter uma comparação com os coeficientes analíticos de sustentação e arrasto. Testes de campo foram realizados em um protótipo de 20 kW de acordo com a norma IEC-60041 e sua comparação com o método analítico e por consequência o método numérico validou o método empregado para confecção das pás do rotor e distribuidor. / The purpose of this work is to present a methodology to design a small axial hydraulic turbine with emphasis on the project of the profiles of the runner and wicket gate, including both analytical and numerical results from a cascade panel method. Comparisons with field test measurements of a prototype are also presented. The analytical methodology used is the Wenigs inviscid flow theory which requires the evaluation of interference factors to model how lift and drag characteristics of the turbine cascade of blades are related to those of a single isolated airfoil. It is found that the Wenigs theory provides a reasonable prediction of the lift interference factor if both the angle of attack is relatively low and the thickness of the blades is relatively small when compared to the distance between the blades. The numerical methodology that relies the Hess and Smiths 2-D panel method for a cascade of blades and for an isolated airfoil was used in order to have a comparison with the analytical lift and drag. Prototype field test measurements of the turbine power output, in agreement with IEC-60041 standards, were carried out to evaluate the results using the analytical and numerical methods.

Orientador: Lubienska Cristina Lucas Jaquiê Ribeiro / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Tecnologia / Made available in DSpace on 2018-08-20T06:43:15Z (GMT). No. of bitstreams: 1 Aleixo_AlineSerpeloni_M.pdf: 2178208 bytes, checksum: aaef09b93f33ada98dd56e8ff5a84ba0 (MD5) Previous issue date: 2012 / Resumo: Uma das principais tarefas de controle numa Usina Hidrelétrica é a regulação das máquinas hidráulicas. Seu monitoramento faz-se necessário para garantir e estabelecer regras operacionais seguras para a instalação. A turbina é um dos elementos básicos de uma Usina Hidrelétrica e o regulador tipo PID é um dos tipos usados para sua regulação. Os parâmetros do regulador da turbina hidráulica são muito estudados, inclusive verificando seu comportamento através da simulação computacional. As simulações computacionais são ferramentas de análise muito úteis e que permitem encontrar a melhor solução que proporcione o melhor desempenho do sistema estudado. Este trabalho apresenta uma metodologia para otimização das constantes do regulador tipo PID de turbina hidráulica utilizando um modelo de simulação aliado a técnicas atuais de otimização evolutiva baseada nos Algoritmos Genéticos. Os exemplos avaliados mostraram significativa melhora nos valores dessas constantes, mostrando a eficácia do uso dessa ferramenta na área da Hidráulica e possibilitando estudos futuros / Abstract: One of the main tasks of control in a Hydroelectric Power Plant is the hydraulic machines regulation. Its monitoring becomes necessary to guarantee and to establish safe operational rules for the installation. The turbine is one of the basic elements of the Hydroelectric Power Plant and the PID governor is one of the types used to its regulation. The governor parameters of the hydaulic turbine are studied, also verifying its behavior through the computational simulation. The computational simulations are very useful analysis tools to find the best solution to provide the best performance of the studied system. This work presents a methodology to optimize the PID governor parameters of the hydraulic turbine using a simulation model ally the current techniques of evolutionary optimization based in the Genetic Algorithms. The evaluated examples had shown significant improvement in the constants values, showing the effectiveness use of this tool in the hydraulic area and making possible future studies / Mestrado / Tecnologia e Inovação / Mestre em Tecnologia

The aim of this thesis is to design a geometry of runner of high specific speed turbine which is supposed to provide the maximum flow rate of the turbine while achieving a relatively high hydraulic efficiency. New design is based on the analysis of the hydraulic characteristics of three previous design sof very hiát specific speed turbines. The actual hydraulic pdesign of the turbine runner is based on CFD computations. Special software tools like BladeGen and TurboGrid were used for petting up the geometry and mesh for the very first time at Kaplan Department of Fluid Engineering.

This master thesis is devoded to examination of influence of bumped leading edge of hydraulic turbines ruber blade to characteristics of blade cascade. Thesis is based on hydraulic turbine which countoured/bumped leading edge of blade was created using previous studies on NACA profiles. The main goal of this thesis is to Compare shaped leading edge with flat leading edge using CFD calculations. Programms like SolidWorks and Gambit were used to calculate geometrics and meshes.

Global renewable energy requirements rapidly increase with the transition to a fossil-free society. As a result, intermittent energy resources, such as wind- and solar power, have become increasingly popular. However, their energy production varies over time, both in the short- and long term. Hydropower plants are therefore utilized as a regulating resource more frequently to maintain a balance between production and consumption on the electrical grid. This means that they must be operated away from the design point, also known as the best-efficiency-point (BEP), and often are operated at part-load (PL) with a lower power output. Moreover, some plants are expected to provide a spinning reserve, also referred to as speed-no-load (SNL), to respond rapidly to power shortages. During this operating condition, the turbine rotates without producing any power. During the above mentioned off-design operating conditions, the flow rate is restricted by the closure of the guide vanes. This changes the absolute velocity of the flow and increases the swirl, which is unfavorable. The flow field can be described as chaotic, with separated regions and recirculating fluid. Shear layer formation between stagnant- and rotating flow regions can be an origin for rotating flow structures. Examples are the rotating-vortex-rope (RVR) found during PL operation and the vortical flow structures in the vaneless space during SNL operation, which can cause the flow between the runner blades to stall, also referred to as rotating stall. The flow structures are associated with pressure pulsations throughout the turbine, which puts high stress on the runner and other critical parts and shortens the turbine's lifetime. Numerical models of hydraulic turbines are highly coveted to investigate the detrimental flow inside the hydraulic turbines' different sections at off-design operating conditions. They enable the detailed study of the flow and the origin of the instabilities. This knowledge eases the design and assessment of mitigation techniques that expand the turbines' operating range, ultimately enabling a wider implementation of intermittent energy resources on the electrical grid and a smoother transition to a fossil-free society. This thesis presents the numerical study of the Porjus U9 model, a scaled-down version of the 10 MW prototype Kaplan turbine located along the Luleå river in northern Sweden. The distributor contains 20 guide vanes, 18 stay vanes and the runner is 6-bladed. The numerical model is a geometrical representation of the model turbine located at Vattenfall Research and Development in Älvkarleby, Sweden. The commercial software ANSYS CFX 2020 R2 is used to perform the numerical simulations. Firstly, the draft tube cone section of the U9 model is numerically studied to investigate the sensitivity of a swirling flow to the GEKO (generalized kω) turbulence model. The GEKO model aims to consolidate different eddy viscosity turbulence models. Six free coefficients are changeable to tune the model to flow conditions and obtain results closer to an experimental reference without affecting the calibration of the turbulence model to basic flow test cases. Especially, the coefficients affecting wall-bounded flows are of interest. This study aims to analyze if the GEKO model can be used to obtain results closer to experimental measurements and better predict the swirling flow at PL operation compared to other eddy viscosity turbulence models. Results show that the near-wall- and separation coefficients predict a higher swirl and give results closer to experimentally obtained ones. Secondly, a simplified version of the U9 model is investigated at BEP and PL operating conditions and includes one distributor passage with periodic boundary conditions, the runner and the draft tube. The flow is assumed axisymmetric upstream of the runner, hence the single distributor passage. Previous studies of hydraulic turbines operating at PL show difficulties predicting the flow's tangential velocity component as it is often under predicted. Therefore, a parametric analysis is performed to investigate which parameters affect the prediction of the tangential velocity in the runner domain. Results show that the model predicts the flow relatively well at BEP but has problems at PL; the axial velocity is overpredicted while the tangential is underpredicted. Moreover, the torque is overpredicted. The root cause for the deviation is an underestimation of the head losses. Another contributing reason is that the runner extracts too much swirl from the flow, hence the low tangential velocity and the high torque. Sensitive parameters are the blade clearance, blade angle and mass flow. Finally, the full version of the U9 model is analyzed at SNL operation, including the spiral casing, full distributor, runner and draft tube. During this operating condition, the flow is not axisymmetric; vortical flow structures extend from the vaneless space to the draft tube and the flow stalls between the runner blades. A mitigation technique with independent control of each guide vane is presented and implemented in the model. The idea is to open some of the guidevanes to BEP angle while keeping the remaining ones closed. The aim is to reduce the swirl and prevent the vortical flow structures from developing. Results show that the flow structures are broken down upstream the runner and the rotating stall between the runner blades is reduced, which decreases the pressure- and velocity fluctuations. The flow down stream the runner remains mainly unchanged.

Orientador: Carlos Roberto Minussi / Resumo: Nesta pesquisa apresentam-se os principais conceitos gerais de estabilidade elétrica, assim como suas divisões e classificações, onde são desenvolvidas as condições de operação de um sistema elétrico de potência, que são relevantes nos estudos de estabilidade angular do rotor, tensão e frequência. Para os estudos de estabilidade da frequência e de tensão é preciso conhecer os equipamentos como os reguladores de tensão e frequência, em consequência é apresentada a modelagem matemática de vários componentes dinâmicos como o sistema de excitação, estabilizador do sistema de potência (PSS), sistema de regulação de velocidade, sistema de regulação de tensão (AVR), máquina síncrona, turbina a vapor e turbina hidráulica. É necessário a modelagem de eles para projetar seus respectivos controladores. Nesta pesquisa também se faz a introdução ao controlador Fuzzy e controlador PID convencional assim como os métodos de sintonia, depois projetamos um controlador que combine os dois controladores e tenha mais vantagens como o controlador híbrido PID-Fuzzy. Depois de desenvolver a modelagem do regulador de tensão e frequência, fazemos o projeto do controlador PID-Fuzzy, previamente projetado o controle PID. As simulações dos sistemas de regulação de tensão e frequência sem controlador, com controlador PID e com controlador PID-Fuzzy foram realizadas aplicando a ferramenta computacional de Matlab-Simulink no domínio do tempo contínuo e as respostas foram investigadas e discutidas. / Abstract: This research presents the main general concepts of electrical stability, as well as their divisions and classifications, where the operating conditions of an electrical power system are developed, which are relevant in the studies of angular stability of the rotor, voltage and frequency. For frequency and voltage stability studies it is necessary to know equipment such as voltage and frequency regulators, consequently the mathematical modeling of several components is presented as dynamic as the excitation system, power system stabilizer (PSS) , speed regulation system, voltage regulation system (AVR), synchronous machine, steam turbine and hydraulic turbine. We need the modeling of them to design their respective controllers. In this investigation we also do the introduction to the Fuzzy controller and conventional PID controller as well as the tuning methods then we designed a controller that combines the two controllers and has more advantages as the hybrid PID-Fuzzy controller. After developing the modeling of the voltage and frequency regulator, we design the PID-Fuzzy controller, previously designed the PID control. The simulations of the voltage and frequency regulation systems without controller, with PID controller and with PID-Fuzzy controller were performed applying the Matlab-Simulink computational tool in the continuous time domain and the answers were investigated and discussed. / Mestre

Vodní energie se nyní stala nejlepším zdrojem elektrické energie na zemi. Vyrábí se pomocí energie poskytované pohybem nebo pádem vody. Historie dokazuje, že náklady na tuto elektrickou energii zůstávají konstantní v průběhu celého roku. Vzhledem k mnoha výhodám, většina zemí nyní využívá vodní energie jako hlavní zdroj pro výrobu elektrické energie.Nejdůležitější výhodou je, že vodní energie je zelená energie, což znamená, že žádné vzdušné nebo vodní znečišťující látky nejsou vyráběny, také žádné skleníkové plyny jako oxid uhličitý nejsou vyráběny, což činí tento zdroj energie šetrný k životnímu prostředí. A tak brání nebezpečí globálního oteplování. Použití internetové techniky k ovladání několika vodních elektráren má velmi významné výhody, jako snížení provozních nákladů a flexibilitu uspokojení změny poptávky po energii na straně spotřeby. Také velmi efektivně čelí velkým narušením elektrické sítě, jako je například přidání nebo odebrání velké zátěže, a poruch. Na druhou stranu, systém získávání dat poskytuje velmi užitečné informace pro typické i vědecké analýzy, jako jsou ekonomické náklady, predikce poruchy systémů, predikce poptávky, plány údržby, systémů pro podporu rozhodování a mnoho dalších výhod. Tato práce popisuje všeobecný model, který může být použit k simulaci pro sběr dat a kontrolní systémy pro vodní elektrárny v prostředí Matlab / Simulink a TrueTime Simulink knihovnu. Uvažovaná elektrárna sestává z vodní turbíny připojené k synchronnímu generátoru s budicí soustavou, generátor je připojen k veřejné elektrické síti. Simulací vodní turbíny a synchronního generátoru lze provést pomocí různých simulačních nástrojů. V této práci je upřednostňován SIMULINK / MATLAB před jinými nástroji k modelování dynamik vodní turbíny a synchronního stroje. Program s prostředím MATLAB SIMULINK využívá k řešení schematický model vodní elektrárny sestavený ze základních funkčních bloků. Tento přístup je pedagogicky lepší než komplikované kódy jiných softwarových programů. Knihovna programu Simulink obsahuje funkční bloky, které mohou být spojovány, upravovány a modelovány. K vytvoření a simulování internetových a Real Time systémů je možné použít bud‘ knihovnu simulinku Real-Time nebo TRUETIME, v práci byla použita knihovna TRUETIME.