the islamic university of gaza faculty of engineering civil...
TRANSCRIPT
(6) Flow over weirs
Prepared By :
Eng. Ruba Awad
2015
The Islamic University of Gaza
Faculty of Engineering
Civil Engineering Department
ENGC 6341
- Purpose:
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To investigate the discharge-head characteristics of a rectangular and triangular weirs:
1. To observe characteristics of flow over a weir.
2. To determine the head-discharge relationship of two
different shapes of weirs, and to compare the experimental
results with their corresponding theoretical expressions.
3. Calculating the coefficient of discharge (Cd).
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- Apparatus:
1.
1. Rectangular and triangular notches
2. Hydraulic bench.
3. Basket of glass spheres.
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- Equipment set up:
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glass spheres
hold the standard weir in place,
Flow measurement
Measuring the weir datum
Measuring the head
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-Theory:
(1)Rectangular Weir
(B = 30 mm)
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2/323
2HgBQ ltheoretica
time
volumeHgBCQ
QCQ
dactual
ltheoreticadactual
23
23
2
)H 2gB 3
2ln(Cd=)ln(Q 3/2
act
)ln(H)2gB 3
2ln(Cd=)ln(Q 3/2
act
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-Theory: (1) Rectangular Weir
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)ln(H2
3)2g
3
2ln(Cd=)ln(Qact
axisX23
axis- intercept=y
gB
eC
ercept
d
23
2
int
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-Theory:
(2) For Triangular weir ( )
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)2
tan(215
8
int
g
eC
ercept
d
)ln(H2
5)2g
2 tan
15
8ln(Cd=)ln(Qact
axisX25
axis- intercept=y
60
Equipment preparation and Procedures:
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- Data & Results:
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• Plot a graph of against for each weir.
• Measure the slopes and the intercepts.
• Calculate the coefficient of discharge from the intercept and confirm that the slope is approximately 2.5 for the rectangular notch and 1.5 for the triangular notch.
- Data & Results:
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THANKS