International Journal of Fluid Machinery and Systems

Korean Society for Fluid machinery (한국유체기계학회)
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Cavitation Compliance in 1D Part-load Vortex Models

  • Received : 2017.02.27
  • Accepted : 2017.06.12
  • Published : 2017.06.30
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Abstract

When Francis turbines operate at partial load, residual swirl in the draft tube causes low-frequency pulsation of pressure and power output. Scale effects and system response may bias the prediction of prototype behavior based on laboratory tests, but could be overcome by means of a 1D analytical model. This paper deals with the two most important features of such a model, the compliance and the source of excitation. In a distributed-parameter version, compliance should be represented as an exponential function of local pressure. Lack of similarity due to different Froude number can thus be compensated. The normally unknown gas content in the vortex cavity has significant influence on the pulsation, and should therefore be measured and considered as a test parameter.

Keywords

References

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