Question

- When subcritical flow goes over a step down, does the kinetic energy increase, decrease or remain constant?

- You have subcritical flow going through a channel constriction that does not influence upstream water levels. If the critical depth is observed in the constriction, the minimum specific discharge is passing through the constriction

True or false?

- Subcritical flow encounters a step up transition that is smaller than the maximum step height. Does the specific energy:

		increase
		decrease
		remain the same

- In supercritical flow that does not encounter a hydraulic structure, the upstream water is influenced by downstream conditions.

True or False?

Answer 1

- The effect of down step the channel bottom beneath a subcritical approaching flow. The depth decreases over the transition, and the mean flow velocity increases so the value of kinetic energy will increses.

-FALSE:-

The condition of minimum specific energy is known as the critical flow condition and the corresponding depth yc is known as critical depth and the critical depth gives the greatest specific discharge.

- The effect of step up (raising) the channel bottom beneath a subcritical
approaching flow and also the step up transition that is smaller than the maximum step height so depth decreases over the transition, and result of this the value of specific energy will also increases. You can assess this by the observation of depth-specific energy curve.

- TRUE:-

The flow in supercritical flow the depth upstream of the step increases. Instead of having no effect on the upstream flow, as was the case for lower steps(subcritical flow), the step now acts as a dam: its effect is felt far upstream.

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