Hydraulic jump over a weir

Hydraulic jump is the jump of water that takes place when a supercritical flow changes into a

subcritical flow.

* Froude number F =

where v = velocity of flow

y = depth of flow

g = gravitational attraction

* If incoming Froude No. F1

is

F1 = 1, no hydraulic jump

F1 = 1 to 1.7, undulates jump is observed

F1 = 2.5 to 4.5, oscillating jump is observed

F1 = 4.5 to 9.0, steady jump is observed

F1 ≥ 9.0, strong jump.

* The loss of head in hydraulic jump is given by HL =

where y1 = depth of water on upstream

y2 = depth of water on upstream