LABORATORY OUTCOME BASED ASSESSMENT GUIDELINE No

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LABORATORY OUTCOME BASED ASSESSMENT GUIDELINE
TOPIC EXPERIMENT: REYNOLDS NUMBER
PROGRAM LEARNING OUTCOMES (PLO)
Upon completion of this course, students should be able to:
1. Apply knowledge of mathematics, science and engineering fundamentals to well defined civil engineering
theories and procedures.
2. Use necessary skills and technique to conduct experiment and civil engineering practices
3. Communicate effectively both in written and spoken form with other collegue and community.
4. Provide effective solution to civil engineering problems.
5. Develop social responsibilities and humanistics values
6. Recognise the need and to engage in, lifelong learning and professional
development.
7. Apply entrepreneurship skill for career development.
8. Adhere to professional codes of ethics to adapt in working environment.
9. Demonstrate effective leaderships skills and team work responsibilities.
COURSE LEARNING OUTCOMES (CLO)
Upon completion of this course, students should be able to:1. Explain clearly the fluid characteristics, fluid pressure and solve problems in flow of fluid using
Bernoulli’s Equation(C4)
2. Apply principles to solve problems in laminar and turbulent flow and relation to Reynolds number,
Darcy’s and Hagen-Poiseuille equation for problem solving (C3)
3. Apply appropriate knowledge in minor loss in pipe and uniform flow in open channel (C3)
4. Conduct correctly methods and procedures of hydraulics solution towards practical problems (P2)
5. Demonstrate positive team working attributes by contributing actively in group for laboratory tests that
yield valid results (A3)
No.
1.0
2.0
3.0
4.0
5.0
Lab.Title
Teaching
Method
PLO
CLO
GSA / LD
2&9
4&5
LD 2 & LD 9
Fluid Characteristics
Bernoulli Theorem
Reynolds Number
Practical
Fluid Friction Test
Uniform Flow
Learning Domain (LD):
Generic Student Attributes (GSA):
GSA 1 Communications Skills
GSA 2 Critical Thinking and Problem
Solving Skills
GSA 3 Teamwork Skills
GSA 4 Moral and Professional Ethics
GSA 5 Leadership Skills
GSA 6 Information Management Skills and
Continuous Learning
GSA 7 Entrepreneurship Skills
LD 1 Knowledge
LD 2 Practical Skills
LD 3 Communicatio Skills
LD 4 Critical Thinking and Problem
Solving skills
LD 5 Social Skills and Resposibilities
LD 6 Continious Learning and
Information Management Skills
LD 7 Menagement and Entepreneurial
Skills
LD 8 Professioalism , Ethics and
Moral
LD 9 Leadership and Teamwork Skiils
NO. EXPERIMENT
: 3
TOPIC EXPERIMENT
: REYNOLDS NUMBER
OBJECTIVE
:
• To observe the characteristics of the flow of a fluid in
a pipe, this may be laminar, transitional or turbulent
flow by measuring the Reynolds number and the
behavior of the flow.
• To calculate and identify Reynolds number (Re) for
the laminar, transitional and turbulent flow.
APPARATUS
: Hydraulic bench
Osborne Reynolds Demonstration Apparatus
Stop watch
Dye
Thermometer
Measuring cylinder
Figure 1: Osborne Reynolds Demonstration Apparatus
1. Base Plate
8. Test Pipe Section
2. Water Reservoir
9. Ball Block
3. Overflow Section
10. Waste Water Discharge
4. Aluminium Well
11. Connections for Water Supply
5. Metering Tap
12. Drain Cock
6. Brass Inflow Tip
13. Control valve
7. Flow-Optimised Inflow
THEORY :
Osborne Reynolds in 1883 conducted a number of experiments to
determine the Laws of Resistance in pipes to classify types of flow. Reynolds
number 'Re' is the ratio of inertia force to the viscous force where viscous force is
shear stress multiplied area and inertia force is mass multiplied acceleration.
Reynolds determined that the transition from laminar to turbulent flow occurs at a
definite value of the dimensionally property, called Reynolds number:
Re = ρvd
or
Re= vd
µ

Where:
v = flow velocity (m/s)
ρ = density (kg/m3)
d = inside diameter of pipe section (m)
µ = dynamic viscosity of the fluid (kg/ms)
Q = volumetric flow rate (m3/s)
A = cross sectional area of the pipe (m2)
 = kinematics viscosity (m2/s)
Reynolds carried out experiments to decide limiting value of Reynold's
number to a quantitatively decide whether the flow is laminar or turbulent. The
limits are as given below:
•Laminar when Re < 2300
•Transition when 2300 < Re < 4000
•Turbulent when Re > 4000
(a)
(b)
(c)
Figure 2 : Three flow regimes: (a) laminar, (b) transitional & (c) turbulent
The motion is laminar or turbulent according to the value of Re is less than
or greater than a certain value. If experiments are made with decreasing rate of
flow, the value of Re depends on degree of care which is taken to eliminate the
disturbances in the supply or along the pipe. On the others hand, if experiments
are made with decreasing flow, transition from turbulent to laminar flow takes
place at a value of Re which is very much depends on initial disturbances. The
valve of Re is about 2000 for flow through circular pipe and below this the flow is
laminar in nature. The velocity at which the flow in the pipe changes from one
type of motion to the other is known as critical velocity.
PROCEDURES :
1. Firstly, the apparatus is set up and measure and note down diameter of pipe
and also room temperature. Fill the aluminum well with dye, the metering tap
(dye flow control valve) and drain cock must be closed.
2. Switch on the pump, carefully open the control valve above the pump and
adjust the tap to produce a constant water level in the reservoir. After a time
the test pipe section is completely filled.
3. Open the drain cock slightly to produce a low rate of flow into the test pipe
section.
4. Open the metering tap and the dye is allowed to flow from the nozzle at the
entrance of the channel until a colored stream is visible along the test pipe
section. The velocity of water flow should be increased if the dye accumulates
around the nozzle.
5. Adjust the water flow until a laminar flow pattern which is a straight thin line or
streamline of dye is able to be seen along the whole test pipe section.
6. Collect the time in seconds for the 10 liters volume of colored waste water that
flows down at the outlet pipe. The volume flow rate is calculated from the
volume and a known time.
7. Repeat step 5-6 with increasing rate of flow by opening the drain cock and the
flow pattern of the fluid is observed as the flow changes from laminar to
transition and turbulent. Take five to six readings till the dye stream in the test
pipe section breaks up and gets diffused in water.
8. Clean all the apparatus after the experiment is done.
RESULTS :
Inside diameter of pipe section,d =
0.010 m
Cross sectional area of the pipe, A = ____________m2
Density of water, ρ = _________ kg/m3
Kinematics viscosity of water at room temperature,  = ______m2/s (see Table 1)
Average room temperature,Ө = _________ºC
Run
Volume,V
Time,t
Flow rate,Q
Velocity, v
Reynolds
Type of
No
(m3)
(s)
(m3/s)
(m/s)
Number(Re)
Flow
1
2
3
4
5
6
FORMULA :
A = (π d2 / 4)
Q=V/t
Re = ( ρvd / µ )
or
V=Q/A
Re = vd / 
QUESTIONS :
1. What is Reynold's number?
2. State some practical examples of laminar and turbulent flow?
3. State the difference between laminar flow and turbulent flow?
4. What is the behavior of path lines?
i) Laminar flow
iii) Transitional flow
ii) Turbulent flow
5. What are the application of Reynolds's No. other than type of flow?
Table 1: Kinematic Viscosity, v of Water at Atmospheric Pressure
Temperature
(degrees C)
Kinematic
Viscosity , 
(10 -6 x m2/s)
Temperature
(degrees C)
Kinematic
Viscosity , v
(10 -6 x m2/s)
0
1.793
25
0.893
1
1.732
26
0.873
2
1.674
27
0.854
3
1.619
28
0.836
4
1.568
29
0.818
5
1.520
30
0.802
6
1.474
31
0.785
7
1.429
32
0.769
8
1.386
33
0.753
9
1.346
34
0.738
10
1.307
35
0.724
11
1.270
36
0.711
12
1.235
37
0.697
13
1.201
38
0.684
14
1.169
39
0.671
15
1.138
40
0.658
16
1.108
45
0.602
17
1.080
50
0.554
18
1.053
55
0.511
19
1.027
60
0.476
20
1.002
65
0.443
21
0.978
70
0.413
22
0.955
75
0.386
23
0.933
80
0.363
24
0.911
85
0.342
Eg. 20 º C the kinematic viscosity of water is 1.002 x 10 -6 m2/s
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