Les problèmes vibratoires sont l'une des principales causes des maintenances effectuées sur les turbines de barrages hydroélectrique en France. Dans cette thèse CIFRE, subventionnée par la Division Technique Générale d’Électricité de France à Grenoble, nous voulons étudier numériquement les phénomènes physiques en jeu.Pour cela, chaque partie composant ce type de machine tournante est modélisée : la ligne d'arbre, les accouplements rigides, les paliers hydrodynamiques, la butée hydrodynamique à patins oscillants, les étanchéités et les efforts électromagnétiques. Celui du rotor est basé sur une approche classique 1D, prenant en compte des défauts d'accouplement rigide. Les paliers hydrodynamiques peuvent être alimentés par des rainures hélicoïdales : ceci est pris en compte dans la modélisation des paliers via un changement de variable dans l'équation de Reynolds. Concernant la butée hydrodynamique à patins oscillants, l'équation de Reynolds est explicitée en fonction des paramètres du système (rotor et patins). Un cas test est également présenté afin d'évaluer les différentes approches possibles pour l'intégration dans la modélisation du rotor et pour mieux appréhender la réponse dynamique d'une butée. Les joints d'étanchéités sont modélisés en linéarisant les efforts hydrauliques gouvernés par les équations du "bulk-flow" et sont donc représentés par des coefficients dynamiques de masse, d'amortissement et de raideur. Les efforts électromagnétiques au niveau de l'alternateur sont pris en compte via une formulation analytique des forces d'attraction sur chaque paire de pôles. Cela permet de gérer, par exemple, des défauts d'ovalisation ou de positionnement du stator.Une seconde partie est consacrée à l'étude d'une turbine complète. Y sont présentées différentes études de sensibilités des défauts les plus courants sur ce type de machine, le but étant d'en connaître l'influence sur le comportement dynamique de l'ensemble du rotor. / Vibration problems are one of the main causes leading to maintenances performed on the turbines of hydroelectric power generation systems in France. In this CIFRE dissertation, financed by Division Technique Générale d'Électricité de France in Grenoble, we shall numerically study the physical phenomena involved in turbine vibrations of this kind.Hence, each component of this type of rotating machinery is modeled: the rotor, the rigid coupling, the hydrodynamic bearings, the hydrodynamic tilting pad thrust bearing, the annular seals and the electromagnetic forces. The model of the rotor is based on classical 1D approach taking into account the defects of the rigid coupling. The hydrodynamic bearings can be fed by helicoidally grooves. This feature is taken into account in the numerical model of journal bearing by applying a variable transformation to the Reynolds equation. For the tilting pad thrust bearing, the Reynolds equation takes into account the displacements and the velocities of both the pads and the rotor. A test case is presented for evaluating the different numerical approaches of the tilting pad thrust bearing that can be integrated in a rotordynamic analysis. The annular seals are modeled by using linearized hydraulic efforts (i.e. stiffness, damping and added mass dynamic coefficients) modeled by the "bulk flow" system of equations. The electromagnetic efforts in the alternator are taken into account by using an analytic model of the forces of each pair of poles. This enables to tackle ovalisation or eccentricity defects of the stator.A second part is dedicated to the numerical study of a complete turbine. Different studies dealing with sensitivity analyses of most often-encountered defects of this type of rotating machinery are presented, the goal being to underline their influence on the dynamic behavior of the whole rotor.

The demand on high efficiency pumps leads the manufacturers to develop new design and manufacturing techniques for rotodynamic pumps. Computational Fluid Dynamics (CFD) software are started to be used during the design periods for this reason in order to validate the designs before the pumps are produced. However the integration process of CFD software into the design procedure should be made carefully in order to improve the designs. In this thesis, the CFD software is aimed to be integrated into the pump design procedure. In this frame, a vertical turbine type mixed flow pump is aimed to be designed and design improvements are intended to be made by applying numerical experimentations on the pump. The pump that is designed in this study can deliver 115 l/s flow rate against the head of 16 mWC in 2900 rpm. The effects of various parameters in the design are investigated by the help of CFD software during the design and best performance characteristics of the pump are aimed to be reached. The pump that is designed in this study is manufactured and tested in Layne Bowler Pumps Company Inc. The design point of the pump is reached within the tolerance limits given in the related standard. In addition, the results of actual test and numerical experimentation are compared and found to be in agreement with each other. The integration of CFD code to the design procedure is found quite useful by means of shortening design periods, lowering manufacturing and testing costs. In deed the effects of the design parameters are understood better by applying numerical experimentations to the designed pump.

In this thesis a vertical turbine mixed flow pump that has a flow rate of 40 l/s and 16 mwc head at 2900 rpm is designed. Effect of design parameters are investigated and flow inside the pump is analyzed with the help of numerical experimentations. The designed pump is manufactured and tested in Layne Bowler Pumps Company and completed in T&Uuml / BiTAK - TEYDEB project. Pump is designed in the tolerance limits that are defined in the standard TS EN ISO 9906. Numerical experimentation results for performance charecteristics show the same trend with the test results. In addition, axial thrust measurements are done on the designed pump with using load cells. Effect of balancing holes and balancing ring are investigated. Balancing holes are drilled at various diameters at the back side of the impellers and its effect is analyzed on the pump performance characteristics. Test results are compared with different approaches.

This master’s thesis deals with the dynamic behaviour of vertical Francis turbine, which is atypical its shaft length. In the first part of thesis, there is theoretic research of water turbine, which is followed by derivation of equations for the Stodola rotor. The second part deals with the creation of the turbine shaft in 1D and 3D. A modal analysis was performed in the ANSYS Workbench software, based on which the Campbell diagram is created and it was determined the critical speed. And the harmonic analysis from which was determined the forces response in radial bearings, amplitude of deviation in radial direction in the turbine impeller and the generator and the axial displacement located in turbine impeller and axial bearing. 1D and 3D solutions were compared between themselves.