Eastern Mediterranean University
Department of Mechanical Engineering
Laboratory Handout
COURSE: MENG 353 – Fluid Mechanics
Semester: Fall (2019-2020)
Name of Experiment: Friction Loss Across a Pipe
Instructor: Assoc. Prof.: Hasan Hacisevki
Assistants: Erfan Malekian
Submitted by: Rana Khaled
Student No.: 17700169
Date of Experiment: Dec., 20th, 2019
Date of Submission: Dec., 27th, 2019
--------------------------------------------------------------------------------------------------------------------EVALUATION
Activity During Experiment & Procedure
30 %
Data, Results, and Graphs
35%
Discussion, Conclusion, Answers to Questions
30%
Neat and Tidy Report Writing
Overall Mark
5%
Table of Contents
Introduction .....................................................................................................................3
Procedure ........................................................................................................................4
Calculations .....................................................................................................................4
Discussion and conclusion ...............................................................................................6
Introduction
This experiment is mainly about determining the flow type, whether laminar or
turbulent. This is achieved by using a piezometer to read piezometeric head and calculate the
friction factor accordingly. Below is a model of the utilized piezometer connected to a Utube manometer, shown in Figure 1. This experiment is usually done utilizing Mercury as the
working fluid, however, in this experiment the fluid was water.
Figure 1 Piezometer
Procedure
Our aim is mainly to read the heads, or heights, of the piezometer; but not only that,
the amount of water was also needed as well as the time the water took in seconds to reach
the required amount from a measurement of 0L to 15L. The experiment has very simple
steps, shown as follows;
1. Empty out the manometer’s tubes of any air bubbles.
2. Start water flow with the desired velocity.
3. Record the time taken of the water to reach a volume of 15L using a timer.
4. Record the two heights of the U-tube, one will always be greater than the
other.
5. Siphon the water to empty the tubes, then repeat of two more times.
Calculations
A few parameters were given, other parameters were obtained from the experiment,
and some parameters need to be calculated to determine the flow type and consequently the
friction factor. Also, water temperature was taken as room temperature 25℃. The given
parameters;
𝐿 = 524 𝑚𝑚
𝐷 = 3.00 𝑚𝑚
𝐴 = 7.069 𝑚𝑚2
To be calculated;
𝑅𝑒 =
𝜌×𝑣×𝐷
𝑘𝑔
, µ = 8.91 × 10−3 , 𝜌 = 997.0 ⁄𝑚3
µ
16
𝑅𝑒
𝑓𝐿𝑎𝑚𝑖𝑛𝑎𝑟 =
𝑓𝑇𝑢𝑟𝑏𝑢𝑙𝑒𝑛𝑡 =
0.079
4
√𝑅𝑒
Table 1 Data Results
Volume
(L)
15
Time
(s)
41.26
𝟑
Q (𝒎 ⁄𝒔)
15
15
𝒉𝟏 (𝒎)
𝒉𝟐 (𝒎)
Re
f
0.000364
Velocity
(𝒎⁄𝒔)
0.05143
0.25
0.116
172.641
0.09268
Gradient
(i)
0.25573
37.74
0.000397
0.05623
0.254
0.082
188.743
0.08477
0.32824
33.41
0.000449
0.06351
0.258
0.034
213.204
0.07505
0.42748
As shown above in Table 1, all Re values are less than 2,300, which indicates a
laminar flow. The flowrate, gradient, and friction factor sample calculations are shown
below;
𝑄=
𝑖=
𝑉
𝑡
=
ℎ1−ℎ2
𝐿
15×10−3
41.26
=
3
= 0.00364 𝑚 ⁄𝑠
0.25−0.116
16
0.524
16
= 0.25573
𝑓𝐿𝑎𝑚𝑖𝑛𝑎𝑟 = 𝑅𝑒 = 172.64 = 0.09268
Reynold's Number
Gradient (i)
0
50
100
150
200
250
0.45
0.4
0.35
0.3
0.25
0.2
0.15
0.1
0.05
0
0
0.01
0.02
0.03
0.04
0.05
0.06
0.07
Velocity (m/s)
Gradient to Velocity
Gradient to Reynold's Number
Figure 2 Gradient to Reynold's Number & Velocity.
Shown, in Fig. 2 is a graph connecting Reynold’s number to the gradient and
velocity. A relation between them is represented; the gradient has a linear relation with
respect to Reynold’s number and the velocity, where, as either increase the gradient increases
as well. This concludes a linear proportional relationship. Reynold’s number also depends on
the velocity and has a proportional relation with it; as velocity increases Reynold’s number
increases and vice-versa.
Discussion and conclusion
In conclusion, the flow type has been determined as laminar when Reynold’s number
was computed, which varied depending on the varying flow velocities. We observed a
proportional relationship between each of the gradient, Reynold’s number, and the velocity,
shown in Figure 2. The liquid utilized was water, which made calculations simpler, since this
experiment usually takes place utilizing Mercury and water running through the manometer
U-tube.