Hydraulic jump Froude number Types of hydraulic jump Height of hydraulic jump

1. SV COLLEGE OF AGRIL.ENGG. AND
TECHNOLOGY , RESEARCH STATION , RAIPUR
(C.G.)
ASSIGNMENT ON – HYDRAULIC JUMP
SUBMITTED TO
DR. D . KHALKHO SIR
PROFESOR
SUBMITTED BY
NAME – VIDYACHARAN RATHIA
ROLL NO. 20202292
CLASS – 3RD YEAR 2ND SEM

2. Hydraulic jump
• Super critical flow in a channel of small slope is unable
to sustain it ; therefore , super critical flow tends to
change in sub – critical flow . In super critical state , the
depth of flow is less than the critical depth while in sub-
critical condition , it is greater than the critical depth .
• Thus , when flow changes from super critical state to
sub-critical state , then depth of flow gets increase . This
increase in depth of flow is effective for a shorter length ,
is know as hydraulic jump

3. Applications of Hydraulic jump
• Used to dissipate the energy of flowing water over the weirs ,
dams and other hydraulic structures . The energy dissipation
of flowing water is helpful to prevent soil scouring at down
stream section of the hydraulic structures , in significant way .
• To raise the water level on d/s (demand to supply) side of the
measuring flume , this property is beneficial to create high
water level in irrigation channel , and thus to make easy water
distribution at every corners of the field .
• It is used to increase the water weight on apron section ; and
thus to reduce the uplift pressure below masonry structure by
raising the water depth within the apron section . The uplift
pressure can be estimated with the help of water depth
existing over the hydraulic structure .

4. • Hydraulic jump is employed for locating the gauging
station , as it creates the special flow conditions such as
existence of super critical flow or the presence of control
sections in the stream .
• For domestic / city water supply it is used to acrate the
water.
• For water purification the hydraulic jump makes a
complete mixing of chemicals in the water.
• It is also applied to remove the air pockets from the
water supply lines ; and thus removing the problem of
air locking from there.

5. Froude number
The effect of gravity upon the state of flow is represented by a ratio of
inertia forces to gravity forces . This ratio is given by froude number
, defined as :
Fr = v/( (gd)1/2
Where ,
v = mean velocity of flow , m/s
g = acceleration of gravity ,m/sq.s
d = depth of flow , m

6. Types of hydraulic jump
(based on froude number )
• At F = 1, the flow is said to be critical ; in this flow no hydraulic
jump forms .
• At F= 1 to 1.7 , the water surface includes some undulation i.e. Jump
occurs , called as undular jump.
• At F= 1.7 to 2.5 , a weak jump occurs , which is characterised by
having a series of small rollers on the surface of jump
- loss of energy is very low .
• At F = 2.5 to 4.5 , an oscillating type hydraulic jump takes place .
The oscillation produces a large wave of irregular period . This type
of jump formation is more common in canals .

7. • At F = 4.5 to 9.0 , a steady jump forms . This types of hydraulic
jumps are least sensitive to change the tail water depth . They are
always in well balanced condition and have performance at their
best .
- about 45 to 70 % energy is dissipated .
• At F>=9.0 , a strong hydraulic jump takes place . In this type of
hydraulic jump , a high velocity jet grabs inermittent slugs of water
rolling down the front face of the jump and generating the waves at
downstream side , as result a rough surface is prevailed , there. Its
action is rough , but more effective to dissipate the energy .
- the energy dissipation may reach upto 85% .