Now showing items 21-40 of 60

    • Dynamic response of the MICA runner. Experiment and simulation 

      Valentín Ruiz, David; Presas Batlló, Alexandre; Egusquiza Estévez, Eduard; Valero Ferrando, Ma. del Carmen; Bossio, Matias (Institute of Physics (IOP), 2017)
      Conference report
      Open Access
      Studying the dynamic response of Francis turbine runners is of paramount importance in order to avoid resonance problems during operating conditions. For this purpose, the natural frequencies as well as their associated ...
    • El Diagnóstico de daños en grupos hidroeléctricos mediante el análisis de vibraciones 

      Egusquiza Estévez, Eduard; Nascimento, Luiz de Paula do; Valero Ferrando, Ma. del Carmen; Jou Santacreu, Esteban (1994)
      Article
      Open Access
      El análisis del comportamiento vibratorio de Grupos Hidroeléctricos se puede utilizar para el diagnóstico del estado de la máquina. Se pretende detectar daños incipientes y poder seguir la evolución del estado de la máquina ...
    • Experimental analysis of the dynamic behavior of a rotating disk submerged in water 

      Presas Batlló, Alexandre; Valentín Ruiz, David; Egusquiza Estévez, Eduard; Valero Ferrando, Ma. del Carmen; Seidel, Ulrich (2014)
      Conference report
      Open Access
      To study the dynamic behavior of turbine runners (natural frequencies and mode shapes) not only the added mass effect of still water has to be considered. Also the effect of rotation may not be neglected in the dynamic ...
    • Experimental investigation on the dynamic response of Pelton runners 

      Egusquiza Montagut, Mònica; Valero Ferrando, Ma. del Carmen; Presas Batlló, Alexandre; Valentín Ruiz, David; Egusquiza Estévez, Eduard (Institute of Physics (IOP), 2019)
      Conference report
      Open Access
      An effective condition monitoring is essential to increase the availability of Pelton turbines and to avoid unexpected damage. The main challenge consists in determining the deformations and the stresses in the runner while ...
    • Experimental measurements of the natural frequencies and mode shapes of rotating disk-blades-disk assemblies from the stationary frame 

      Presas Batlló, Alexandre; Valentín Ruiz, David; Valero Ferrando, Ma. del Carmen; Egusquiza Montagut, Mònica; Egusquiza Estévez, Eduard (Multidisciplinary Digital Publishing Institute, 2019-09-14)
      Article
      Open Access
      Determining the natural frequencies and mode shapes of rotating turbomachinery components from both rotating and stationary reference frames is of paramount importance to avoid resonance problems that could affect the ...
    • Experimental study of a vibrating disk submerged in a fluid-filled tank and confined with a nonrigid cover 

      Valentín Ruiz, David; Presas Batlló, Alexandre; Egusquiza Estévez, Eduard; Valero Ferrando, Ma. del Carmen; Egusquiza Montagut, Mònica (2017-04-01)
      Article
      Restricted access - publisher's policy
      Determining the dynamic response of submerged and confined disklike structures is of interest in engineering applications, such as in hydraulic turbine runners. This dynamic response is heavily affected by the added mass ...
    • Experimental study on the added mass and damping of a disk submerged in a partially fluid-filled tank with small radial confinement 

      Valentín Ruiz, David; Presas Batlló, Alexandre; Egusquiza Estévez, Eduard; Valero Ferrando, Ma. del Carmen (2014-07-16)
      Article
      Restricted access - publisher's policy
      The dynamic response of submerged and confined disk-like structures is of interest in engineering applications, such as in hydraulic turbine runners. This response is difficult to be estimated with accuracy due to the ...
    • Extension of operating range in pump-turbines. Influence of head and load 

      Valero Ferrando, Ma. del Carmen; Egusquiza Montagut, Mònica; Egusquiza Estévez, Eduard; Presas Batlló, Alexandre; Valentín Ruiz, David; Bossio, Matias (2017-12-19)
      Article
      Open Access
      Due to the increasing share of new renewable energies like wind and solar in the generation of electricity the need for power regulation and energy storage is becoming of paramount importance. One of the systems to store ...
    • Failure investigation of a Kaplan turbine blade 

      Zhang, Ming; Valentín Ruiz, David; Valero Ferrando, Ma. del Carmen; Egusquiza Montagut, Mònica; Egusquiza Estévez, Eduard (Elsevier, 2019-03-01)
      Article
      Open Access
      In this paper, an uncommon failure of a Kaplan turbine blade has been analyzed. After the monitoring system detected a sudden increase in vibration levels, the turbine was inspected. The inspection showed that a large crack ...
    • Failure investigation of a large pump-turbine runner 

      Egusquiza Estévez, Eduard; Valero Ferrando, Ma. del Carmen; Huang, Xingxing; Guardo Zabaleta, Alfredo de Jesús; Jou Santacreu, Esteban; Rodríguez, Cristian (Elsevier, 2012-02-02)
      Article
      Open Access
    • Failure investigation of a Pelton turbine runner 

      Egusquiza Montagut, Mònica; Egusquiza Estévez, Eduard; Valentín Ruiz, David; Valero Ferrando, Ma. del Carmen; Presas Batlló, Alexandre (Elsevier, 2017-11)
      Article
      Open Access
      In this paper, an uncommon failure of a Pelton turbine has been analyzed. After the monitoring system detected a sudden increase in the vibration levels, the turbine was inspected. The inspection showed that a fragment of ...
    • Failure investigation of a solar tracker due to wind-induced torsional galloping 

      Valentín Ruiz, David; Valero Ferrando, Ma. del Carmen; Egusquiza Montagut, Mònica; Presas Batlló, Alexandre (Elsevier, 2022-05-01)
      Article
      Open Access
      Solar power installations are increasing every year due to the decarbonization policy established around the world. Photovoltaic (PV) systems and specifically one-axis solar trackers are the most used type of installations ...
    • Feasibility of detecting natural frequencies of hydraulic turbines while in operation, using strain gauges 

      Valentín Ruiz, David; Presas Batlló, Alexandre; Bossio, Matias; Egusquiza Montagut, Mònica; Egusquiza Estévez, Eduard; Valero Ferrando, Ma. del Carmen (Multidisciplinary Digital Publishing Institute (MDPI), 2018-01-10)
      Article
      Open Access
      Nowadays, hydropower plays an essential role in the energy market. Due to their fast response and regulation capacity, hydraulic turbines operate at off-design conditions with a high number of starts and stops. In this ...
    • Feasibility of Using PZT Actuators to Study the Dynamic Behavior of a Rotating Disk due to Rotor-Stator Interaction 

      Presas Batlló, Alexandre; Egusquiza Estévez, Eduard; Valero Ferrando, Ma. del Carmen; Valentín Ruiz, David; Seidel, Ulrich (2014-07-01)
      Article
      Restricted access - publisher's policy
      In this paper, PZT actuators are used to study the dynamic behavior of a rotating disk structure due to rotor-stator interaction excitation. The disk is studied with two different surrounding fluids-air and water. The study ...
    • Increasing the operating range and energy production in Francis turbines by an early detection of the overload instability 

      Zhao, Weiqiang; Presas Batlló, Alexandre; Egusquiza Montagut, Mònica; Valentín Ruiz, David; Egusquiza Estévez, Eduard; Valero Ferrando, Ma. del Carmen (2021-08)
      Article
      Open Access
      With the increasing entrance of wind and solar power for the generation of electricity, more flexibility is demanded to hydropower plants. More flexibility means that hydro turbines have to increase the operating range ...
    • Influence of non-rigid surfaces on the dynamic response of a submerged and confined disk 

      Valentín Ruiz, David; Presas Batlló, Alexandre; Egusquiza Estévez, Eduard; Valero Ferrando, Ma. del Carmen (2015)
      Conference report
      Open Access
      Determining the dynamic response of submerged and confined disk-like structures is of interest in the hydraulic turbines field. Disks present similar dynamic characteristics than hydraulic turbine runners, especially in ...
    • Influence of the added mass effect and boundary conditions on the dynamic response of submerged and confined structures 

      Valentín Ruiz, David; Presas Batlló, Alexandre; Egusquiza Estévez, Eduard; Valero Ferrando, Ma. del Carmen (2014)
      Conference report
      Open Access
      The dynamic response of submerged and confined disk-like structures is of interest in the flied of hydraulic machinery, especially in hydraulic turbine runners. This response is difficult to be estimated with accuracy due ...
    • Influence of the boundary conditions on the natural frequencies of a Francis turbine 

      Valentín Ruiz, David; Ramos Martín, David; Bossio, Matias; Presas Batlló, Alexandre; Egusquiza Estévez, Eduard; Valero Ferrando, Ma. del Carmen (Institute of Physics (IOP), 2016)
      Conference report
      Open Access
      Natural frequencies estimation of Francis turbines is of paramount importance in the stage of design in order to avoid vibration and resonance problems especially during transient events. Francis turbine runners are submerged ...
    • Influence of the hydrodynamic damping on the dynamic response of Francis turbine runners 

      Valentín Ruiz, David; Presas Batlló, Alexandre; Valero Ferrando, Ma. del Carmen; Egusquiza Montagut, Mònica; Jou Santacreu, Esteban; Egusquiza Estévez, Eduard (2019-10-01)
      Article
      Open Access
      The dynamic behavior of Francis runners is of interest in the hydraulic machinery field since it is one of the most used type of hydraulic turbines for electricity generation. To evaluate the dynamic behavior of Francis ...
    • Modal behavior of a reduced scale pump-turbine impeller. Part II. Numerical Simulation 

      Valero Ferrando, Ma. del Carmen; Huang, Xingxing; Egusquiza Estévez, Eduard; Farhat, Mohamed; Avellan, François (2010)
      Conference lecture
      Restricted access - publisher's policy
      A numerical simulation has been carried out to analyze the modal behavior of a reduced scale pump-turbine impeller. The simulation has been done using FEM method, in air and in water. The same boundary conditions than ...