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Gradually Varied Flow(GVF)

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Assumption used to analyse gradually varied flow(GVF)

A steady, non-uniform flow in which depth of flow varies gradually along the length of the channel is called gradually varied flow.
To analyse Gradually varied flow, following assumptions are made:

  1. Channel is a prismatic channel section and alignment remains same.
  2. Bed slope is small, i.e. So=Sf.
  3. Energy loss is same for a uniform flow at a section having same velocity and hydraulic radius.
  4. Energy correction factor a=1.
  5. Roughness co-efficient is independent of depth of flow and constant throughout the channel.

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