notch and its type

1. WHAT ARE NOTCHES AND
THEIRS TYPES

2. INTRODUCTION
A notch is a device used for measuring the rate of
flow of a liquid through a small channel or tank .
Due to notches the pressure energy of liquid is
converted into kinetic energy.

3. Classification of notches
The notches are classified as:
 According to the shape of opening
1. Rectangular notch
2. Triangular notch
3. Trapezoidal notch

4. Rectangular notch
 A rectangular shaped notch that is usually installed at the end of
upstream It Offers more pressure drop.
 Flow rate in rectangular notch is dependent on the depth of
upstream
 The equation of discharge over the rectangular notch
Q= 2/3.Cd.L.√(2g).H^(3/2)

5. Triangular notch
Often called as a v notch. Useful for measuring low flow rate . Pressure
loss is recovered.
The equation of discharge over the Triangular notch is given by
Q=8/15.Cd.√(2g).Tan(ᶿ/2).H^(5/2)

6. Trapezoidal notch
 It is the combination of rectangular notch and the two triangular
notch
 Discharge over the trapezoidal notch will be the sum of discharge
of rectangular notch and triangular notch
 Discharge over the trapezoidal notch is given as
Q=2/3.Cd.L.√(2g).H^(3/2)+8/15.Cd.√(2g).Tan(ᶿ/2).H^(5/2)

7. DIFFERENCE BETWEEN NOTCHES
AND WIRE
NOTCH
1. A notch may be defined as an opening
provided in one side of a tank or reservoir,
with u/s liquid level below the top edge of
the opening.
2. The bottom edge of notch over which water
flows is known as sill or crest.
3. A notch is usually made of a metallic plate
4. A notch is used to measure small discharge of
small stream or canal.
5. Notches are of small size.
WIER
1. A weir may be defined as a
structure constructed across a river
or canal to store water on the
upstream side
2. The top of the weir over which
water flows is known as crest.
3. A weir is made of cement concrete
or masonary.
4. A weir is used to measure large
discharge of rivers and large canals.
5. Weirsd are of bigger size.

8. GROUP MEMBERS
NAME REG#
USAMA PERVAIZ FA16-CHE-114
MUHAMMAD SHABAN FA16-CHE-074
AWAIS AHMED FA16-CHE-61
MUHAMMAD JHANZAIB FA16-CHE-112
MUHAMMAD BILAL FA16-CHE-039
MUHAMMAD UZAIR FA16-CHE- 37