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The depth of flow is the same at every section of the channel. Uniform flow can be steady or unsteady, depending on whether or not the depth changes with time, (although unsteady uniform flow is rare). Varied flow. The depth of flow changes along the length of the channel. Varied flow technically may be either steady or unsteady.
Gradually varied flow occurs when the change in flow depth per change in flow distance is very small. In this case, hydrostatic relationships developed for uniform flow still apply. Examples of this include the backwater behind an in-stream structure (e.g. dam, sluice gate, weir, etc.), when there is a constriction in the channel, and when ...
Nappe flow regimes occur for small discharges and flat slopes. If the discharge is increased or the slope of the channel is increased, a skimming flow regime can occur (Shahheydari et al. 2015). Nappe flow has pockets of air at each step whereas skimming flow does not. The onset of skimming flow can be defined as: (d c)=1.057*h - 0.465*h 2 /l ...
A is the cross sectional area of flow (L 2); P is the wetted perimeter (L). For channels of a given width, the hydraulic radius is greater for deeper channels. In wide rectangular channels, the hydraulic radius is approximated by the flow depth.
The Chézy formula describes mean flow velocity in turbulent open channel flow and is used broadly in fields related to fluid mechanics and fluid dynamics. Open channels refer to any open conduit, such as rivers, ditches, canals, or partially full pipes. The Chézy formula is defined for uniform equilibrium and non-uniform, gradually varied flows.
Parshall flumes (right) alongside other types of flow meters. The Parshall flume is an open channel flow-metering device that was developed to measure the flow of surface water and irrigation flow.
This example is a very basic hydraulic jump situation where the flow approaches at a supercritical depth, y 1, and jumps to its subcritical conjugate depth, y 2, in order to obtain the necessary energy to continue moving down the channel with the given flow rate, q. Figure 6. M-y Diagram
In a nozzle or other constriction, the discharge coefficient (also known as coefficient of discharge or efflux coefficient) is the ratio of the actual discharge to the ideal discharge, [1] i.e., the ratio of the mass flow rate at the discharge end of the nozzle to that of an ideal nozzle which expands an identical working fluid from the same initial conditions to the same exit pressures.