What is the normal depth of a channel in uniform flow?

[Pyrrhus]

I've been reading a bit on open channels. I am wondering in uniform flow (constant Volume flow and constant cross section), the normal height or normal depth of the channel if it is the critical height or depth (when Froude's number is 1). The book doesn't make a relation about it, but i believe it is, because it's the min energy (potential+kinetic) to keep the flow, plus in uniform flow there's no acceleration. What about supercritical and subcritical, i would imagine the inertial forces > gravitational forces in the latter (also because the flow tends to be turbulent), while in the former gravitational forces > inertial forces, right?

 

[Pyrrhus]

Any takers?

 

[ravenprp]

The normal depth of a channel in uniform flow is the depth at which the flow is at its most stable and efficient state. This depth is also known as the critical depth, and it is when the Froude number is equal to 1. This means that the inertial forces and gravitational forces are in balance, resulting in a constant velocity and energy throughout the channel.

In supercritical flow, the flow velocity is greater than the critical velocity, resulting in a Froude number greater than 1. In this case, the inertial forces are greater than the gravitational forces, leading to a more turbulent flow. The normal depth in supercritical flow is shallower than the critical depth.

On the other hand, in subcritical flow, the flow velocity is lower than the critical velocity, resulting in a Froude number less than 1. In this case, the gravitational forces are greater than the inertial forces, leading to a smoother and more stable flow. The normal depth in subcritical flow is deeper than the critical depth.

Overall, the normal depth of a channel in uniform flow is an important factor to consider in order to maintain a stable and efficient flow. It is also influenced by the Froude number, which is a ratio of the flow velocity to the critical velocity.