The
flow beneath a sluice may be free or submerged,
depending on the depth of the tailwater. When the
tailwater is low, the flow is free, and the
discharge through the sluice is maximized. When the
tailwater is increased, the flow beneath the sluice
may become submerged and the discharge through the
sluice will be reduced. For many applications it is
desirable to maintain a free discharge through a
sluice. For these situations a hydraulic jump may
be used to hold back the tailwater. In situations
where the downstream depth is larger than the
sequent depth for a normal jump, a drop in the
channel floor may be used to ensure a jump (note:
the fluid is colored by turbulent kinetic
energy).
