The flow will be in super critical state in the following profile:

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UPPSC AE Civil 2013 Official Paper I

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Answer 1

Concept:

Flow is classified based on Froude’s number which is given as

\({{\rm{F}}_{\rm{r}}}{\rm{\;}} = {\rm{\;}}\frac{{\rm{V}}}{{\sqrt {{\rm{g}}\frac{{\rm{A}}}{{\rm{T}}}} }}\)

Where, y_c = critical depth of flow.

Flow profile in gradually varied flow for mild and steep slope is shown below:

For mild slope:

(NDL is above CDL)

For steep slope:

(CDL is above NDL)

Thus, the depth of flow is less than the critical depth of flow in the case of S₂, S₃ and M₃ profiles.

Hence flow is supercritical in case of S₂, S₃ and M₃ profiles.