Fluid Mechanics (Venturi Flowmeter)
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Abueid.docxVenturi Flow meter Abudullah Eid
Course: BEng in Mechanical Engineering
Stage: 2
Academic Year: 2017/2018
Subject: Fluid Mechanics
Lecturer: Fergal O Rourke
Laboratory Experiment Report
Student Name: Abdullah Aleid
Experiment/Assignment Tittle: Venturi Flow meter
Date of Experiment: 10/11/2017
Date Report Handed Up: 16/12/2017
Table of Contents
1.0 Readings
The readings recorded for the venturi flow meter during the experiment are shown in table 1:
Table 1: Readings Recorded for venturi flow meter
|
Settings |
H1 (m) |
H2(m) |
Time (for 10kg) |
Diameter 1 (m) |
Diameter 2(m) |
|
1 |
0.205 |
0.068 |
24.805 |
0.026 |
0.016 |
|
2 |
0.24 |
0.035 |
19.92 |
0.026 |
0.016 |
|
3 |
0.18 |
0.065 |
31.595 |
0.026 |
0.016 |
|
4 |
0.21 |
0.14 |
40.62 |
0.026 |
0.016 |
|
5 |
0.215 |
0.16 |
46.735 |
0.026 |
0.016 |
|
6 |
0.094 |
0.05 |
51.755 |
0.026 |
0.016 |
2.0 Results
The results calculated for the venturi flow meter are shown in table 2:
Table 2: Results Calculated for venture flowmeter
|
Settings |
Area 1 (m2) |
Area 2(m2) |
Actual Flow rate[l/s) |
Theoretical Flow rate [l/s] |
Co efficient of discharge |
|
1. |
5.31E-04 |
2.01E-04 |
4.03E-01 |
3.56E-04 |
1.13E+03 |
|
2. |
5.31E-04 |
2.01E-04 |
5.02E-01 |
4.36E-04 |
1.15E+03 |
|
3. |
5.31E-04 |
2.01E-04 |
3.17E-01 |
3.26E-04 |
9.70E+02 |
|
4. |
5.31E-04 |
2.01E-04 |
2.46E-01 |
2.55E-04 |
9.67E+02 |
|
5. |
5.31E-04 |
2.01E-04 |
2.14E-01 |
2.26E-04 |
9.48E+02 |
|
6. |
5.31E-04 |
2.01E-04 |
1.93E-01 |
2.02E-04 |
9.57E+02 |
With the help of reading graph theoretical flow rate against actual flow rate shown in figure 1:
Figure 1: Graph of theoretical flow rate against actual flow rate
3.0 Analysis
It is clear from the results and the graph that the actual flow rate is directly proportional to the theoretical flow rate. The straight trend line proves that the relational between actual flow rate and theoretical flow rate is directly proportional. The coefficient of the x (1061.9) in the equation (y = 1061.9x) obtained in the graph represents the coefficient of discharge. The results obtained can’t be said precise because the points on the graph are not in the straight line. There must be some errors in the experiment.
On comparing the coefficient of discharge it is found that as the actual flow rate increases, coefficient of discharge also increases. This shows that the relationship between coefficient of discharge and actual flow rate is directly proportional.
When a fluid passes through a pipe and the area of pipe reduces (i.e. the pipe becomes narrower, the velocity of the fluid increases with a respective drop in static pressure This principle is known as venturi effect. The venturi effect is a version of Bernoulli’s Principle but venturi effect considered more precise for flow of fluids. There are many applications of venture effect one of them is the spray nozzles. For example in a perfume bottle, pressing of the nozzle causes compressed air to be ejected out of a narrow opening at a high speed. The perfume chamber is connected to this zone, and the low pressure developed causes the liquid molecules to get mixed with the air and get forced out.
Calculation of Actual flow rate when the theoretical flow rate for the venturi flow meter is calculated to be 1.5litres per second. The actual flow rate will be
|
Actual flow rate = coefficient of discharge x theoretical flow rate
=1061.9 x 1.5 = 1592.85 l/s
|
Actual Flowrate ( Vact) [l/s)
y = 1061.9x
3.561670394561983E-4 4.3568275807740961E-4 3.2631900114266419E-4 2.5459065756062174E-4 2.2567049811753788E-4 2.0184582972282124E-4 0.40314452731304173 0.50200803212851397 0.3165057762304162 0.2461841457410143 0.21397239756071468 0.19321804656554922Theoretical Flowrate
Actual Flowrate
5
