open channels

Open channel flow

has a free surface on top and uses gravity driven flow

Examples of open channel flow

Streams, rivers, sewers, ditches, culverts, bridges

What is freudes number

The interaction between inertia and gravity used

Prismatic cross section

Cross section uniform across entire length

nonuniform flow

Cross section varies in shape

Hydraulic depth

Area divided by width

Gradually varied flow

Occurs when little to no transition of water depth

Rapidly varied flow

Occurs when there is a significant change in the depth of water

Hydraulic jump

Occurs when there is an abrupt transition from RVF to GVF

Surge wave

Occurs when a sluice gate is closed, makes an abrupt change in the water depth in a wave flowing back upstream from where the gate was closed

Flux

Change in physical property over time in a defined control surface or control volume

Turbulence

Mixing, aka fluctuating rotations at many scales

Surface drag

Drag factor that occurs along the boundaries of an object (ex. Beds and banks)

Form drag

Drag factor that occurs because of the body shape of the object (ex. baffles and columns and proven by the hand test out of car)