Journal of Advanced Marine Engineering and Technology

The Korean Society of Marine Engineering (한국마린엔지니어링학회)
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Hydrodynamic performance of a pump-turbine model in the "S" characteristic region by CFD analysis

  • Singh, Patrick Mark (Graduate School, Department of Mechanical Engineering, Mokpo National University) ;
  • Chen, Chengcheng (Graduate School, Department of Mechanical Engineering, Mokpo National University) ;
  • Choi, Young-Do (Department of Mechanical Engineering, Institute of New and Renewable Energy Technology Research, Mokpo National University)
  • Received : 2015.10.26
  • Accepted : 2015.12.17
  • Published : 2015.12.31
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Abstract

Specific hydrodynamic characteristic of pump-turbine during the start and load rejection process of generating mode causes anomalous increase of water pressure, along with large machine vibration, called "S" characteristic. The aim of this study is to understand and explain the hydrodynamic performance of pump-turbine at "S" characteristic region by using a model of pump-turbine system. The operation in the condition of runway and low discharge in a typical "S" characteristic curve may become unstable and complex flow appears at the passage of guide vane and impeller. Therefore, velocity and pressure distribution are investigated to give an all-sided explanation of the formation and phenomenon of this characteristic, with the assistance of velocity triangle analysis at the impeller inlet. From this study, the internal flow and pressure fluctuation at the normal, runway and low discharge points are explored, giving a deep description of hydrodynamic characteristic when the pump-turbine system operates with "S" characteristic.

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References

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