Now showing items 21-40 of 45

    • 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
      Restricted access - publisher's policy
      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 ...
    • 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 ...
    • 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
      Restricted access - publisher's policy
      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 ...
    • Numerical and experimental analysis of the dynamic response of large submerged trash-racks 

      Huang, Xingxing; Valero Ferrando, Ma. del Carmen; Egusquiza Estévez, Eduard; Presas Batlló, Alexandre; Guardo Zabaleta, Alfredo de Jesús (2013-01-30)
      Article
      Restricted access - publisher's policy
      This paper investigates the effect of water in the dynamic response of large trash-racks used in hydropower plants. These are large structures that are fully submerged in water and located in the hydraulic circuits to ...
    • Numerical and experimental analysis of the dynamic response of large submerged trash-racks 

      Huang, Xingxing; Valero Ferrando, Ma. del Carmen; Egusquiza Estévez, Eduard; Presas Batlló, Alexandre; Guardo Zabaleta, Alfredo de Jesús (2013)
      Article
      Restricted access - publisher's policy
      This paper investigates the effect of water in the dynamic response of large trash-racks used in hydropower plants. These are large structures that are fully submerged in water and located in the hydraulic circuits to ...
    • Numerical study on the dynamic behavior of a francis turbine runner model with a crack 

      Zhang, Ming; Valentín Ruiz, David; Valero Ferrando, Ma. del Carmen; Egusquiza Montagut, Mònica; Zhao, Weiqiang (2018-01-01)
      Article
      Open Access
      Crack appearance in the blade is the most common type of fatigue damage in Francis turbines. However, it is sometimes difficult to detect cracks in time using the current monitoring system, even when they are very large. ...
    • Numerical study on the influence of acoustic natural frequencies on the dynamic behaviour of submerged and confined disk-like structures 

      Bossio, Matias; Valentín Ruiz, David; Presas Batlló, Alexandre; Ramos Martín, David; Egusquiza Estévez, Eduard; Valero Ferrando, Ma. del Carmen; Egusquiza Montagut, Mònica (2017-08)
      Article
      Open Access
      The dynamic response of disks has been deeply studied in the last years given that their dynamic characteristics present similarities with more complex disk-like structures used in real engineering applications, such as ...
    • On the capability of structural–acoustical fluid–structure interaction simulations to predict natural frequencies of rotating disklike structures submerged in a heavy fluid 

      Valentín Ruiz, David; Presas Batlló, Alexandre; Egusquiza Estévez, Eduard; Valero Ferrando, Ma. del Carmen (2016-04-13)
      Article
      Restricted access - publisher's policy
      Predicting natural frequencies of rotating disklike structures submerged in water is of paramount importance in the field of hydraulic machinery, since the dynamic response of disks presents similarities to the dynamic ...
    • On the detection of natural frequencies and mode shapes of submerged rotating disk-like structures from the casing 

      Presas Batlló, Alexandre; Valentín Ruiz, David; Egusquiza Estévez, Eduard; Valero Ferrando, Ma. del Carmen; Seidel, Ulrich (2015-08)
      Article
      Open Access
      To avoid resonance problems in rotating turbomachinery components such as impellers, it is of paramount importance to determine the natural frequencies of these parts when they are under operation. Nevertheless, most of ...
    • On the use of PZT-Patches as exciters in modal analysis: application to submerged structures 

      Presas Batlló, Alexandre; Valentín Ruiz, David; Egusquiza Estévez, Eduard; Valero Ferrando, Ma. del Carmen; Egusquiza Montagut, Mònica; Bossio, Matias (Multidisciplinary Digital Publishing Institute (MDPI), 2016)
      Conference report
      Open Access
      Modal Analysis is an experimental technique widely used to determine the dynamic response of structures. One of the most critical part is the selection of the actuator that will excite the tested structure. In many cases, ...
    • Overview of the experimental tests in prototype 

      Egusquiza Estévez, Eduard; Valentín Ruiz, David; Presas Batlló, Alexandre; Valero Ferrando, Ma. del Carmen (Institute of Physics (IOP), 2017)
      Conference report
      Open Access
      Experimental tests in prototype are necessary to understand the dynamic behaviour of the machine during different operating points. Hydraulic phenomena as well as its effect on the structure need to be studied in o rder ...