Ara es mostren els items 60-79 de 96

    • Modal behavior of a reduced scale pump-turbine impeller. Part I. Experiments 

      Escaler Puigoriol, Francesc Xavier; Hutter, J.K.; Egusquiza Estévez, Eduard; Farhat, Mohamed; Avellan, F. (2010)
      Comunicació de congrés
      Accés restringit per política de l'editorial
      An experimental investigation has been carried out to quantify the effects of surrounding fluid on the modal behavior of a reduced scale pump-turbine impeller. The modal properties of the fluid-structure system have been ...
    • 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)
      Comunicació de congrés
      Accés restringit per política de l'editorial
      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 ...
    • Monitoring of rotor-stator interaction in pump-turbine using vibrations mesured with on-board sensors rotating with shaft 

      Rodriguez Godoy, Cristian; Mateos Prieto, Borja; Egusquiza Estévez, Eduard (2014-02)
      Article
      Accés restringit per política de l'editorial
      Current trends in design of pump-turbines have led into higher rotor-stator interaction (RSI) loads over impeller-runner. These dynamic loads are of special interest having produced catastrophic failures in pump-turbines. ...
    • Multi-objective optimization of a hydro-wind-photovoltaic power complementary plant with a vibration avoidance strategy 

      Xiong, Hualin; Egusquiza Montagut, Mònica; Østergaard, Poul Alberg; Pérez Díaz, Juan Ignacio; Sun, Guoxiu; Egusquiza Estévez, Eduard; Patelli, Edoardo; Xu, Beibei; Duan, Hongjiang; Chen, Diyi; Luo, Xingqi (2021-11-01)
      Article
      Accés obert
      Hydropower has the advantages of quickly responding to load variability, which overcomes the unpredictable and unstable variabilities of solar and wind power. Therefore, such power generation can be combined into a ...
    • 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)
      Text en actes de congrés
      Accés obert
      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 ...
    • Nonlinear modal interaction analysis and vibration characteristics of a francis hydro-turbine generator unit 

      Xu, Beibei; Luo, Xingqi; Egusquiza Montagut, Mònica; Ye, Wei; Liu, Jing; Egusquiza Estévez, Eduard; Chen, Diyi; Guo, Pengcheng (Elsevier, 2021-05-01)
      Article
      Accés obert
      The Francis hydro-turbine generator unit (FHTGU) is a typical nonlinear system with the coupling hydraulic, mechanical and electric subsystems. It is a challenge to understand the reasons for its operational failures because ...
    • 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
      Accés restringit per política de l'editorial
      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
      Accés restringit per política de l'editorial
      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 of the fluid – structure interaction in the diffuser passage of a centrifugal pump 

      Fontanals García, Alfred; Guardo Zabaleta, Alfredo de Jesús; Coussirat, Miguel; Egusquiza Estévez, Eduard (CIMNE, 2011)
      Text en actes de congrés
      Accés obert
      Reliable design of turbomachinery is a complex task. In order to gain overall efficiency in the machine performance, designers may have to reduce the gap between the impeller and the diffuser, forcing them to be as closely ...
    • Numerical study of the fluid-structure interaction in the diffuser passage of a centrifugal pump 

      Fontanals García, Alfred; Guardo Zabaleta, Alfredo de Jesús; Coussirat Núñez, Miguel Gustavo; Egusquiza Estévez, Eduard (Centro Internacional de Métodos Numéricos en Ingeniería (CIMNE), 2011)
      Text en actes de congrés
      Accés obert
      Reliable design of turbomachinery is a complex task. In order to gain overall efficiency in the machine performance, designers may have to reduce the gap between the impeller and the diffuser, forcing them to be as closely ...
    • 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
      Accés obert
      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
      Accés restringit per política de l'editorial
      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
      Accés obert
      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 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)
      Text en actes de congrés
      Accés restringit per acord de confidencialitat
      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 ...
    • On the use of neural networks for dynamic stress prediction in Francis turbines by means of stationary sensors 

      Presas Batlló, Alexandre; Valentín Ruiz, David; Zhao, Weiqiang; Egusquiza Montagut, Mònica; Valero Ferrando, Ma. del Carmen; Egusquiza Estévez, Eduard (Elsevier, 2021-06-01)
      Article
      Accés obert
      Nowadays, one of the major mechanical issues of hydraulic turbines and particularly Francis turbines are the failures produced by fatigue. Due to the massive entrance of new renewable energies such as wind or solar, hydraulic ...
    • 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)
      Text en actes de congrés
      Accés obert
      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, ...
    • On the use of vibrational hill charts for improved condition monitoring and diagnosis of hydraulic turbines 

      Zhao, Weiqiang; Presas Batlló, Alexandre; Egusquiza Montagut, Mònica; Valentín Ruiz, David; Egusquiza Estévez, Eduard; Valero Ferrando, Ma. del Carmen (2022-01-22)
      Article
      Accés obert
      To cope with the intermittent power supply of the new renewable energies and demand fluctuations, Francis turbines are required to operate more and more in an extended operating range, far away from the design point. With ...
    • 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)
      Text en actes de congrés
      Accés obert
      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 ...
    • 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
      Accés obert
      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 ...
    • Prediction of the characteristic pressure pulsations in a reversible pump-turbine 

      Fontanals García, Alfred; Guardo Zabaleta, Alfredo de Jesús; Coussirat Núñez, Miguel Gustavo; Moll, Flavio; Egusquiza Estévez, Eduard; Martínez, Germán (2023-11)
      Article
      Accés obert
      Reversible Pump- Turbine turbomachines are frequently used in peaking load hydroelectrical power plants. These plants contribute to satisfy the energy demand during peak load periods. Its dynamic behaviour is influenced ...