1.
1. Introduction:
Introduction:
We’ll go in this experiment to study some of the famous instruments used in flow We’ll go in this experiment to study some of the famous instruments used in flow measurements. And we’ll use the instruments which shown in
measurements. And we’ll use the instruments which shown in fig (1)fig (1)
In this experiment the flow of a fluid was calculated using three method listed below: In this experiment the flow of a fluid was calculated using three method listed below:
a.
a. Sudden Enlargement:
Sudden Enlargement:
Sudden Enlargement
Sudden Enlargement
Fig (1):ℎℎ
= =
,,
==
(
(
))
Where Whereℎℎ
==ℎℎ
−−ℎℎ
= =
,,
==
==
Where,Where,
is the coefficient of discharge.is the coefficient of discharge.b.
b. Venturi Meter:
Venturi Meter:
The flow through venture meter can calculated from the following equations: The flow through venture meter can calculated from the following equations:
==
(
(
))
WhereWhere
==ℎℎ
−−ℎℎ
= =
,,
==
==
Fig (3):
c.
c. Orifices plate:
Orifices plate:
The flow through venturi meter can calculated from the The flow through venturi meter can calculated from the following equation following equation
==
(
(
))
WhereWhere
==ℎℎ
−−ℎℎ
= =
,,
==
==
,,
Where Cd is the co efficient of discharge.Where Cd is the coefficient of discharge.d.
d. Elbows:
Elbows:
The head loss through the elbow The head loss through the elbow
h
h
b. b.Where kb is the coefficient of
Where kb is the coefficient of the elbow (let Kb= 0.5)the elbow (let Kb= 0.5)
= =
,,
==
==
,,
Where Cd is the coefficient of discharge.Where Cd is the coefficient of discharge.e.
e. Rotameter:
Rotameter:
The Rotameter reads the flow directl
The Rotameter reads the flow directl yy..
.
.
= =
.
.
Fig (4):
2.
2. Objective:
Objective:
To study some of tTo study some of t he famous instruments used in flow measurements.he famous instruments used in flow measurements.
To become familiar with Venturi & OriTo become familiar with Venturi & Orifice plate &Variable area meter.fice plate &Variable area meter.
3.
3. Apparatus
Apparatus
::
Water Flow Measuring Apparatus is designed as a free-standing apparatus for use on Water Flow Measuring Apparatus is designed as a free-standing apparatus for use on the Hydraulics Bench, although it could be used
the Hydraulics Bench, although it could be used in conjunction with a low pressure water supply in conjunction with a low pressure water supply controlled by a valve and a discharge to drain. controlled by a valve and a discharge to drain. Water enters the apparatus through the lower Water enters the apparatus through the lower left- hand end and flows horizontally through a left- hand end and flows horizontally through a sudden enlargement into a transparent venturi sudden enlargement into a transparent venturi meter, and into an orifice plate, a 90º elbow meter, and into an orifice plate, a 90º elbow changes the flow direction to vertical and changes the flow direction to vertical and connects to a variable are a flow
connects to a variable are a flow meter, a secondmeter, a second bend passes th
bend passes the flow into a die flow into a discharge pipe whischarge pipe whichch incorporates an atmospheric break.
incorporates an atmospheric break.
4.
4. Procedure:
Procedure:
Prepare the instruments such that the water
Prepare the instruments such that the water passes Sudden Enlargement, then Venturipasses Sudden Enlargement, then Venturi meter, Orifice plate, Elbow, and finally Rotameter.
meter, Orifice plate, Elbow, and finally Rotameter. 2. Switch the pump on, allow
2. Switch the pump on, allow the water to enter the flow the water to enter the flow measurement instruments,measurement instruments, Which are connected to Manometers tubes.
Which are connected to Manometers tubes. 3. Control the flow valve to ob
3. Control the flow valve to obtain different readingtain different readings of the s of the heads in manometers andheads in manometers and The corresponding flow from the volume tank.
The corresponding flow from the volume tank.
Fig (5):
5.
5. Results:
Results:
a.
a.
Sudden Enlargement:
Sudden Enlargement:
A1= A1= 0.0000785 0.0000785 m2 m2 ,, Volume (m3) Volume (m3) 0.01 0.01 0.01 0.01 0.008 0.008 0.0060.006 Time (sec) Time (sec) 135 135 152.4 152.4 142.2 142.2 141141 h1 (m) h1 (m) 0.427 0.427 0.372 0.372 0.324 0.324 0.24850.2485 h2 (m) h2 (m) 0.43 0.43 0.373 0.373 0.338 0.338 0.2490.249 he= h2 – h1 he= h2 – h1 0.003 0.003 0.001 0.001 0.003 0.003 0.00050.0005 V1 (m/s) V1 (m/s) 0.4852 0.4852 0.2801 0.2801 0.4852 0.4852 0.19810.1981 Qth. (m3/s)Qth. (m3/s) 3.809E-053.809E-05 2.199E-052.199E-05 3.809E-053.809E-05 1.56E-051.56E-05 Qact.(m3/s)
Qact.(m3/s) 7.40741E-05 7.40741E-05 6.56168E-05 6.56168E-05 7.40741E-05 7.40741E-05 4.25532E-054.25532E-05
We have a plot with Qact. in Y-Axis and Qthe. In X-Axis See Fig (6) We have a plot with Qact. in Y-Axis and Qthe. In X-Axis See Fig (6)
y = 1.949x y = 1.949x 0 0 0.00001 0.00001 0.00002 0.00002 0.00003 0.00003 0.00004 0.00004 0.00005 0.00005 0.00006 0.00006 0.00007 0.00007 0.00008 0.00008 0 0 0.000.0000050.000010.0000100050.000010.00001550.000.000020.0000250.00000020.0000250.0000330.00.000030003550.000.00004004 Q Q a a c c t t . . Qthe. Qthe.
Fig (6):Sudden Enlargement
Fig (6):Sudden Enlargement
Table (1):
b.
b.
Venturi Meter:
Venturi Meter:
A1=0.0000785 m2 , A1=0.0000785 m2 , Volume (m3) Volume (m3) 0.01 0.01 0.01 0.01 0.008 0.008 0.0060.006 Time (sec) Time (sec) 135 135 152.4 152.4 142.2 142.2 141141 h3(m) h3(m) 0.4490.449 0.388 0.388 0.338 0.338 0.2560.256 h4 (m) h4 (m) 0.393 0.393 0.345 0.345 0.305 0.305 0.2370.237 H = h3 - h4 H = h3 - h4 0.056 0.056 0.043 0.043 0.033 0.033 0.0190.019 V1 (m/s) V1 (m/s) 1.21 1.21 1.061 1.061 0.9291 0.9291 0.7050.705 Qth. (m3/s)Qth. (m3/s) 9.5E-059.5E-05 8.33E-058.33E-05 7.29E-057.29E-05 5.53E-055.53E-05 Qact.(m3/s)
Qact.(m3/s) 7.407 7.407 E-05 E-05 6.56 E-056.56 E-05 5.63 E-055.63 E-05 4.26 E-054.26 E-05
We have a plot with Qact. in Y-Axis and Qthe. In X-Axis See Fig (7) We have a plot with Qact. in Y-Axis and Qthe. In X-Axis See Fig (7)
y = 0.7789x y = 0.7789x 0.00004 0.00004 0.000045 0.000045 0.00005 0.00005 0.000055 0.000055 0.00006 0.00006 0.000065 0.000065 0.00007 0.00007 0.000075 0.000075 0.00008 0.00008 0 0.0.0000004 04 0.0.00000005 05 00.0.00000006 6 00.0.00000007 7 0.0.000000008 8 0.0.00000009 09 0.0.00000011 Q Q a a c c t t . . Qthe Qthe..
Fig (7): Venturi Meter
Fig (7): Venturi Meter
Table (2):
c.
c. Orifices plate:
Orifices plate:
A= A= 0.000113 0.000113 m2 m2 ,, Volume (m3) Volume (m3) 0.01 0.01 0.01 0.01 0.008 0.008 0.0060.006 Time (sec) Time (sec) 135 135 152.4 152.4 142.2 142.2 141141 h6(m) h6(m) 0.434 0.434 0.377 0.377 0.329 0.329 0.250.25 h7 (m) h7 (m) 0.163 0.163 0.162 0.162 0.163 0.163 0.1620.162 H = h6 – h7 H = h6 – h7 0.271 0.271 0.215 0.215 0.166 0.166 0.0880.088 V1 (m/s) V1 (m/s) 2.882 2.882 2.567 2.567 2.256 2.256 1.6421.642 Qth. (m3/s) Qth. (m3/s) 0.0003260.000326 0.000290.00029 0.0002560.000256 0.0001860.000186 Qact.(m3/s)Qact.(m3/s) 7.4074E-05 7.4074E-05 6.56 6.56 E-05E-05 5.63 E-055.63 E-05 4.26 E-054.26 E-05
We have a plot with Qact. in Y-Axis and Qthe. In X-Axis See Fig (8) We have a plot with Qact. in Y-Axis and Qthe. In X-Axis See Fig (8)
When we graph the best line passes
When we graph the best line passes through all points and Zero point and find the slopethrough all points and Zero point and find the slope of this line (Cd) is 0.
of this line (Cd) is 0. 2633.2633.
Table (3):
Table (3):
Orifices plate Readings
Orifices plate Readings
y = 0.2258x y = 0.2258x 0 0 0.00001 0.00001 0.00002 0.00002 0.00003 0.00003 0.00004 0.00004 0.00005 0.00005 0.00006 0.00006 0.00007 0.00007 0.00008 0.00008 0 0 0.0.000000005 5 0.0.000001 01 0.0.000000115 5 0.0.0000002 2 0.0.000002025 5 0.0.000003 03 0.0.0000003535 Q Q a a c c t t . . Qtheo. Qtheo.
Fig (8): Orifices plate
d.
d.
Rotameter:
Rotameter:
Qthe.
Qthe. (Qrot.(Qrot.) ) (L/s) (L/s) 4.15 4.15 3.63 3.63 3.15 3.15 2.22.2 Qact.
Qact. (L/s) (L/s) 0.07410.0741 0.065620.06562 0.05626 0.05626 0.042550.04255
We have a plot with Qact. In Y-Axis and Qthe. In X-Axis See Fig (9) We have a plot with Qact. In Y-Axis and Qthe. In X-Axis See Fig (9)
When we graph the best line passes
When we graph the best line passes through all points and Zero point and find the slopethrough all points and Zero point and find the slope of this line (Cd) is 0.02.
of this line (Cd) is 0.02.
6.
6. Conclusion & Recommendations:
Conclusion & Recommendations:
We see that the flow of a fluid can be measured in many ways. And t
We see that the flow of a fluid can be measured in many ways. And t he expected error he expected error is the human error, if the experimenter red the outputs and calculate incorrectly. And is the human error, if the experimenter red the outputs and calculate incorrectly. And
y = 0.0181x y = 0.0181x 0 0 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.04 0.05 0.05 0.06 0.06 0.07 0.07 0.08 0.08 0 0 00..5 5 1 1 11..5 5 2 2 22..5 5 3 3 33..5 5 4 4 44..55 Q Q a a c c t t . . Qthe. Qthe.
