Ara es mostren els items 26-45 de 96

    • Detailed study of the rotor-stator interaction phenomenon in a moving cascade of airfoils 

      Fontanals García, Alfred; Coussirat Núñez, Miguel Gustavo; Guardo Zabaleta, Alfredo de Jesús; Egusquiza Estévez, Eduard (2010)
      Comunicació de congrés
      Accés restringit per política de l'editorial
      In turbomachinery the Rotor-Stator Interaction (RSI) is an important phenomenon that has a strong influence on the machine behavior. These interactions can have a significant impact on the vibrational and acoustical ...
    • Detection and analysis of part load and full load instabilities in a real Francis turbine prototype 

      Presas Batlló, Alexandre; Valentín Ruiz, David; Egusquiza Estévez, Eduard; Valero Ferrando, Ma. del Carmen (Institute of Physics (IOP), 2017)
      Text en actes de congrés
      Accés obert
      Francis turbines operate in many cases out of its best effici ency point, in order to regulate their output power according to the instantaneous ener gy demand of the grid. Therefore, it is of paramount importance to analyse ...
    • Detection of erosive cavitation on hydraulic turbines through demodulation analysis 

      Presas Batlló, Alexandre; Luo, Yongyao; Valentín Ruiz, David; Egusquiza Montagut, Mònica; Wang, Zhengwei; Valero Ferrando, Ma. del Carmen; Egusquiza Estévez, Eduard (Institute of Physics (IOP), 2018)
      Text en actes de congrés
      Accés obert
      Erosive cavitation in hydraulic turbines affects severely the runner structure, increasing maintenance costs and reducing the remaining useful life of the component. Actual vibro-acoustic techniques used to detect this ...
    • Detection of hydraulic phenomena in francis turbines with different sensors 

      Valentín Ruiz, David; Presas Batlló, Alexandre; Valero Ferrando, Ma. del Carmen; Egusquiza Montagut, Mònica; Egusquiza Estévez, Eduard (Multidisciplinary Digital Publishing Institute (MDPI), 2019-09-19)
      Article
      Accés obert
      Nowadays, hydropower is demanded to provide flexibility and fast response into the electrical grid in order to compensate the non-constant electricity generation of other renewable sources. Hydraulic turbines are therefore ...
    • Diagnostics of a hydraulic turbine failure 

      Egusquiza Montagut, Mònica; Presas Batlló, Alexandre; Valentín Ruiz, David; Valero Ferrando, Ma. del Carmen; Xu, Beibei; Chen, Diyi; Egusquiza Estévez, Eduard (2022)
      Text en actes de congrés
      Accés obert
      This paper presents the failure analysis and diagnostic of a hydraulic turbine. Shortly after a maintenance revision the thrust bearing of the turbine was destroyed when the turbine was put into operation. The damaged ...
    • Dynamic analysis of Francis Runners-Experiment and numerical simulation 

      Lais, Stefan; Qwenguei, Liang; Henggeler, Urs; Weiss, Thomas; Escaler Puigoriol, Francesc Xavier; Egusquiza Estévez, Eduard (2009-10-01)
      Article
      Accés restringit per política de l'editorial
    • Dynamic model for axial motion of horizontal pelton turbine and validation in actual failure case 

      Rodriguez Godoy, Cristian Gabriel; Egusquiza Estévez, Eduard; Egusquiza Montagut, Mònica; Reyes, S.; Zambrano, D.; Tapia Ladino, Juan Antonio (2020-01-01)
      Article
      Accés obert
      Pelton turbines are important machines for power generation from a renewable energy source such as water. For power rates below 20 MW, the rotor of Pelton turbines is usually in horizontal position. Considering ideal ...
    • Dynamic response of a rotating disk submerged and confined. Influence of the axial gap 

      Presas Batlló, Alexandre; Valentín Ruiz, David; Egusquiza Estévez, Eduard; Valero Ferrando, Ma. del Carmen; Seidel, Ulrich (2016-04-01)
      Article
      Accés obert
      In this paper, the natural frequencies and mode shapes of a rotating disk submerged and totally confined inside a rigid casing, have been obtained. These have been calculated analytically, numerically and experimentally ...
    • Dynamic response of Pelton runners: Numerical and experimental analysis in prototypes 

      Egusquiza Montagut, Mònica; Valentín Ruiz, David; Presas Batlló, Alexandre; Egusquiza Estévez, Eduard (Elsevier, 2020-09-01)
      Article
      Accés obert
      Worldwide electricity generation is featured by the growth of intermittent renewable energies. In this context, hydropower plays a fundamental role because it provides flexibility to the power grid and ensures its stability. ...
    • 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)
      Text en actes de congrés
      Accés obert
      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
      Accés obert
      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)
      Text en actes de congrés
      Accés obert
      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 and Numerical Design and Evaluation of a Vibration Bioreactor using Piezoelectric Patches 

      Valentín Ruiz, David; Roehr, Charline; Presas Batlló, Alexandre; Heiss, Christian; Egusquiza Estévez, Eduard; Bosbach, Wolfram A. (Multidisciplinary Digital Publishing Institute (MDPI), 2019-01-21)
      Article
      Accés obert
      n this present study, we propose a method for exposing biological cells to mechanical vibration. The motive for our research was to design a bioreactor prototype in which in-depth in vitro studies about the influence of ...
    • Experimental and numerical investigation on the influence of a large crack on the modal behaviour of a Kaplan turbine blade 

      Zhang, Ming; Valentín Ruiz, David; Valero Ferrando, Ma. del Carmen; Presas Batlló, Alexandre; Egusquiza Montagut, Mònica; Egusquiza Estévez, Eduard (Elsevier, 2020-01-01)
      Article
      Accés obert
      A large crack was discovered on one blade of a Kaplan turbine prototype after the inspection of the machine. In order to know the origin of the crack, a failure analysis was previously carried out (Zhang et al., 2019). To ...
    • Experimental investigation of added mass effects on a hydrofoil under cavitation conditions 

      Torre Rodríguez, Óscar de la; Escaler Puigoriol, Francesc Xavier; Egusquiza Estévez, Eduard; Farhat, Mohamed (2013-03-13)
      Article
      Accés restringit per política de l'editorial
      The influence of leading edge sheet cavitation and supercavitation on the added mass effects experienced by a 2-D NACA0009 truncated hydrofoil has been experimentally investigated in a hydrodynamic tunnel. A non-intrusive ...
    • 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)
      Text en actes de congrés
      Accés obert
      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
      Accés obert
      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 mode shape determination of a cantilevered hydrofoil under different flow conditions 

      De la Torre Rodriguez, Oscar; Escaler Puigoriol, Francesc Xavier; Egusquiza Estévez, Eduard; Farhat, Mohamed (2016-12-01)
      Article
      Accés obert
      The first three mode shapes of a cantilevered NACA0009 hydrofoil were experimentally investigated in air and under different flow conditions in a cavitation tunnel. First and second bending modes and first torsion mode ...
    • 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
      Accés restringit per política de l'editorial
      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
      Accés restringit per política de l'editorial
      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 ...