Now showing items 1-20 of 65

    • A mechanical assembly for experiments of Saos-2 cells under vibration actuation 

      Presas Batlló, Alexandre; Deering, Joseph; Lee, Bryan; Valentín Ruiz, David; Heiss, Christian; Grandfield, Kathryn; Bosbach, Wolfram A. (2019)
      Conference report
      Restricted access - publisher's policy
      Our current experimental work investigates the influence of mechanical vibration on Saos-2 cells. We impose the vibration by using piezoelectric patches and we measure vibration response by a Laser Doppler Vibrometer. We ...
    • A novel condition monitoring methodology based on neural network of pump-turbines with extended operating range 

      Zhao, Weiqiang; Egusquiza Estévez, Eduard; Valero Ferrando, Ma. del Carmen; Egusquiza Montagut, Mònica; Valentín Ruiz, David; Presas Batlló, Alexandre (2019)
      Conference report
      Open Access
      Due to the entrance of new renewable energies, water-storage energy has to be regulated more frequently to keep the stability of power grid. Consequently, pump-turbines have to work under offdesign conditions more than ...
    • Accurate determination of the frequency response function of submerged and confined structures by using PZT-patches 

      Presas Batlló, Alexandre; Valentín Ruiz, David; Egusquiza Estévez, Eduard; Valero Ferrando, Ma. del Carmen; Egusquiza Montagut, Mònica; Bossio, Matias (2017-03-22)
      Article
      Open Access
      To accurately determine the dynamic response of a structure is of relevant interest in many engineering applications. Particularly, it is of paramount importance to determine the Frequency Response Function (FRF) for ...
    • Advanced condition monitoring of Pelton turbines 

      Egusquiza Montagut, Mònica; Valero Ferrando, Ma. del Carmen; Presas Batlló, Alexandre; Valentín Ruiz, David; Bossio, Matias; Egusquiza Estévez, Eduard (2017)
      Conference report
      Restricted access - publisher's policy
      The ability of hydropower to adapt the electricity generation to the demand is necessary to integrate wind and solar energy to the grid. Nowadays hydropower turbines are required to work under harsher operating conditions ...
    • Advanced condition monitoring of Pelton turbines 

      Egusquiza Montagut, Mònica; Egusquiza Estévez, Eduard; Valero Ferrando, Ma. del Carmen; Presas Batlló, Alexandre; Valentín Ruiz, David; Bossio, Matias (2018-04)
      Article
      Open Access
      The ability of hydropower to adapt the electricity generation to the demand is necessary to integrate wind and solar energy into the electrical grid. Nowadays, hydropower turbines are required to work under harsher operating ...
    • Analysis if the dynamic response of pump-turbine runners- Part I: Experiment 

      Presas Batlló, Alexandre; Valero Ferrando, Ma. del Carmen; Egusquiza Estévez, Eduard; Huang, Xingxing; Farhat, Mohamed; Avellan, François (2012)
      Conference report
      Restricted access - publisher's policy
      When in operation, pump-turbine runners have to withstand large pressure pulsations generated by the rotor-stator interaction. The analysis of the dynamic behavior of these structures is necessary to avoid damage. For this ...
    • Analysis of the aerodynamic coefficients in a digital flying body 

      Presas Batlló, Alexandre (Universitat Politècnica de Catalunya / Technishe Universität München, 2008)
      Master thesis (pre-Bologna period)
      Restricted access - confidentiality agreement
    • Analysis of the dynamic behaviour of rotating disk-like structures submerged and confined 

      Presas Batlló, Alexandre (Universitat Politècnica de Catalunya, 2014-11-27)
      Doctoral thesis
      Open Access
      The analysis of the dynamic behaviour of rotating turbomachinery components is of relevant interest to avoid damages or fatigue problems in these parts. To determine the dynamic behaviour of a part of a structure it is ...
    • Analysis of the dynamic response of pump-turbine impellers. Influence of the rotor 

      Egusquiza Estévez, Eduard; Valero Ferrando, Ma. del Carmen; Presas Batlló, Alexandre; Huang, Xingxing; Guardo Zabaleta, Alfredo de Jesús; Seidel, Ulrich (2016-02-01)
      Article
      Open Access
      This paper deals with the dynamic response of pump-turbine impellers. A pump-turbine impeller is a complex structure attached to a rotor and rotating inside a casing full of water with very small clearances between the ...
    • Analysis of the dynamic response of pump-turbine runners. Part I: Experiment 

      Presas Batlló, Alexandre; Valero Ferrando, Ma. del Carmen; Huang, Xingxing; Egusquiza Estévez, Eduard; Farhat, Mohamed; Avellan, François (IOPScience, 2012)
      Conference lecture
      Restricted access - publisher's policy
      When in operation, pump-turbine runners have to withstand large pressure pulsations generated by the rotor-stator interaction. The analysis of the dynamic behavior of these structures is necessary to avoid damage. For this ...
    • Analysis of the mode shapes of Kaplan runners 

      Moraga González, Greco Alonso; Egusquiza Montagut, Mònica; Valentín Ruiz, David; Valero Ferrando, Ma. del Carmen; Presas Batlló, Alexandre (Multidisciplinary Digital Publishing Institute, 2022-07-02)
      Article
      Open Access
      To prevent lifetime shortening and premature failure in turbine runners, it is of paramount importance to analyse and understand its dynamic response and determine the factors that affect it. In this paper, the dynamic ...
    • Behavior of Francis turbines at part load. Field assessment in prototype: Effects on power swing. 

      Valentín Ruiz, David; Presas Batlló, Alexandre; Egusquiza Montagut, Mònica; Valero Ferrando, Ma. del Carmen; Egusquiza Estévez, Eduard (Institute of Physics (IOP), 2019)
      Conference report
      Open Access
      Francis turbines are increasingly demanded to work at part load in order to satisfy the electricity generation demand and to compensate the non-constant generation of other renewable sources such as wind or solar. At part ...
    • Behavior of Francis turbines at part load. Field assessment in prototype: Effects on the hydraulic system. 

      Valero Ferrando, Ma. del Carmen; Egusquiza Montagut, Mònica; Valentín Ruiz, David; Presas Batlló, Alexandre; Egusquiza Estévez, Eduard (Institute of Physics (IOP), 2019)
      Conference report
      Open Access
      At present, hydropower plants play an important role because of their flexibility in the generation of electricity. Today, the required operating range of turbine units is expected to extend to deep part load. At part load ...
    • Cavitation effects on the structural resonance of hydraulic turbines: Failure analysis in a real francis turbine runner 

      Liu, Xin; Luo, Yongyao; Presas Batlló, Alexandre; Wang, Zhengwei; Zhou, Lingjiu (2018-09-03)
      Article
      Open Access
      When discussing potential resonances in hydraulic turbine runners, cavitation effects are usually neglected. Nevertheless, recent studies have experimentally proved, that large cavitation volumes in the proximity of flexible ...
    • Condition monitoring of a prototype turbine. Description of the system and main results 

      Valero Ferrando, Ma. del Carmen; Egusquiza Estévez, Eduard; Presas Batlló, Alexandre; Valentín Ruiz, David; Egusquiza Montagut, Mònica; Bossio, Matias (Institute of Physics (IOP), 2017)
      Conference report
      Open Access
      The fast change in new renewable energy is affecting directly the required operating range of hydropower plants. According to the present demand of electricity, it is necessary to generate different levels of power. Because ...
    • Condition monitoring of pump-turbines. New challenges 

      Egusquiza Estévez, Eduard; Valero Ferrando, Ma. del Carmen; Valentín Ruiz, David; Presas Batlló, Alexandre; Rodriguez Godoy, Cristian (2015-05)
      Article
      Open Access
      At present, pumped storage is the only system to store huge amounts of energy. The surplus of energy in the electrical grid is used for pumping water from a lower to a higher reservoir (pump operation). At peak hours or ...
    • Crack growth analysis and fatigue life estimation in the piston rod of a Kaplan hydro turbine 

      Liu, Xin; Presas Batlló, Alexandre; Luo, Yongyao; Wang, Zhengwei (2018-11)
      Article
      Open Access
      Linear elastic fracture mechanics (LEFM) approaches are seldom used to analyze fatigue problems in hydraulic turbomachinery, where extremely simplified fatigue models are normally considered. In one of the largest Kaplan ...
    • 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)
      Conference report
      Open Access
      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)
      Conference report
      Open Access
      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
      Open Access
      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 ...