Now showing items 1-20 of 23

    • A review of pzt patches applications in submerged systems 

      Presas, Alexandre; Luo, Yongyao; Wang, Zhengwei; Valentín Ruiz, David; Egusquiza Montagut, Mònica (Multidisciplinary Digital Publishing Institute (MDPI), 2018-07-12)
      Article
      Open Access
      Submerged systems are found in many engineering, biological, and medicinal applications. For such systems, due to the particular environmental conditions and working medium, the research on the mechanical and structural ...
    • 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 ...
    • Assessment of the use of Venetian blinds as solar thermal collectors in double skin facades in Mediterranean climates 

      Velasco Vilanova, Abel; Jiménez García, Sergi; Guardo Zabaleta, Alfredo de Jesús; Fontanals García, Alfred; Egusquiza Montagut, Mònica (2017-11-10)
      Article
      Open Access
      The global trend on energy integration and building efficiency is making both researchers and building developers look for technical solutions to use facade surfaces for energy harvesting. In this work, the assessment ...
    • 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 ...
    • 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 ...
    • 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 ...
    • 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 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 ...
    • 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 ...
    • 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 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, ...
    • Power swing generated in Francis turbines by part load and overload instabilities 

      Valentín Ruiz, David; Presas Batlló, Alexandre; Egusquiza Estévez, Eduard; Valero Ferrando, Ma. del Carmen; Egusquiza Montagut, Mònica; Bossio, Matias (2017-12-13)
      Article
      Open Access
      Hydropower plays a key role in the actual energy market due to its fast response and regulation capacity. In that way, hydraulic turbines are increasingly demanded to work at off-design conditions, where complex flow ...
    • Preliminary results on the assessment of using Venetian blinds as a solar thermal collector in double skin facades in Mediterranean climates 

      Guardo Zabaleta, Alfredo de Jesús; Egusquiza Montagut, Mònica; Egusquiza Estévez, Eduard; Alavedra Ribot, Pere (2015)
      Conference report
      Open Access
      The global trend on energy integration and building efficiency is making both researchers and developers look for technical solutions to use façade surfaces for electricity and/or domestic hot water production. These ...
    • Sensor-based optimized control of the full load instability in large hydraulic turbines 

      Presas Batlló, Alexandre; Valentín Ruiz, David; Egusquiza Montagut, Mònica; Valero Ferrando, Ma. del Carmen; Egusquiza Estévez, Eduard (Multidisciplinary Digital Publishing Institute (MDPI), 2018-03-30)
      Article
      Open Access
      Hydropower plants are of paramount importance for the integration of intermittent renewable energy sources in the power grid. In order to match the energy generated and consumed, Large hydraulic turbines have to work under ...