Now showing items 1-12 of 44

    • 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 ...
    • On the exctitation of a submerged disk-like structure with RSI patterns 

      Presas Batlló, Alexandre; Valentín Ruiz, David; Egusquiza Estévez, Eduard; Valero Ferrando, Ma. del Carmen; Seidel, Ulrich (2015)
      Conference report
      Restricted access - confidentiality agreement
      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 ...
    • Transient Analysis of Pelton Turbine Prototypes 

      Egusquiza Montagut, Mònica; Valentín Ruiz, David; Valero Ferrando, Ma. del Carmen; Presas Batlló, Alexandre; Egusquiza Estévez, Eduard (2021)
      Conference report
      Open Access
      One of the most critical operating conditions in hydraulic turbines is the start-up transient. This may be characterized by the presence of several resonances, which increase the vibration and stress levels on the runners. ...
    • 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 ...
    • Natural frequencies of rotating disk-like structures submerged viewed from the stationary frame 

      Presas Batlló, Alexandre; Valentín Ruiz, David; Egusquiza Estévez, Eduard; Valero Ferrando, Ma. del Carmen; Seidel, Ulrich (2021)
      Conference report
      Open Access
      To understand the effect of rotation in the dynamic response of pump-turbine runners, simplified models such as disk-like structures can be used. In previous researches the natural frequencies and mode shapes of rotating ...
    • 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 ...
    • 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 ...
    • 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 ...
    • 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 ...
    • Selection and Optimization of Sensors for Monitoring of Francis Turbines 

      Valentín Ruiz, David; Presas Batlló, Alexandre; Valero Ferrando, Ma. del Carmen; Egusquiza Montagut, Mònica; Egusquiza Estévez, Eduard (2021)
      Conference report
      Open Access
      With the current demand of flexibility to hydraulic turbines, these are working under off-design conditions more than ever. Under these conditions different complex hydraulic phenomena appear, especially in Francis turbines, ...
    • Strain prediction in Francis runners by means of stationary sensors 

      Presas Batlló, Alexandre; Valentín Ruiz, David; Zhao, Weiqiang; Valero Ferrando, Ma. del Carmen; Egusquiza Montagut, Mònica; Egusquiza Estévez, Eduard (2021)
      Conference report
      Open Access
      The assessment of the remaining useful life due to fatigue in Francis turbine runners implies complex measurements with strain gauges that have to be installed in a submerged and rotating structure, which is excited with ...
    • Assessment of turbulence models for the prediction of Bénard- Von Kármán vortex shedding behind a truncated hydrofoil in cavitation conditions 

      Chen, Jian; Geng, Linlin; Torre Rodríguez, Óscar de la; Escaler Puigoriol, Francesc Xavier (Institute of Physics (IOP), 2021)
      Conference report
      Open Access
      The transient cavitating flow in the wake of a hydrofoil at zero incidence angle has been simulated using a homogeneous mixture cavitation mass transfer model combined with both Reynolds Average Navier-Stokes (RANS) and ...