1. The document summarizes an experiment conducted by Muhammad Sulaimon Rasul to determine different types of fluid flow (laminar, transitional, turbulent) using Reynolds apparatus. 2. The experiment measured the volume of water and time taken to fill a graduated cylinder for different flow rates. This was used to calculate Reynolds number to identify flow type. 3. All results showed Reynolds numbers less than 2000, indicating laminar flow for all trials according to the theoretical boundaries between flow types.

1. Soran University
Faculty of Engineering
Department of Petroleum Engineering
Fluid Mechanic
Title: Reynolds Experiment
Experiment No.: 4
Name: Muhammad Sulaimon Rasul
Group: B2
Date: 22 OCT 2019
Supervisors: Ms Marriam, Mr. Shahab, Mr. Sarkar

2. Contents
Aim………………………………………………………………………………………….…….1
Theory…………………………………………………………………………………….…….…1
Apparatus…………………………………………………………...…………………………..…3
Procedure………………………………………………………………………………………….4
Calculation………………………………………………………………………………...………5
Result and Discussion……………………………………………………………………………..6
Conclusion………………………………………………………………………………………...6
References…………………………………………………………………………………………7
List of Figures
Figure 1. Type of Fluid Flows ………………………...………………………………………….2
Figure 2 Blue Ink…………………………………………………………………..……..……….3
Figure 3 Reynold Apparatus………………………………………………………………………3
Figure 4 Graduated Cylinder ……………………………………………………………………..3
Figure 5 Timer…………………………………………………………………………………….3
List of Tables
Table 1: Experimental and Theorical Results……………………………………………………..6

3. Aim
The objective is to determine:
1. The flow type (laminar, transitional, or turbulent) of fluid inside a pipe line.
2. At which condition each type of flow can occur.
Theory
In the 19th
century, the “Reynolds Number” was given to “Osborne Reynolds”, in which performed
an experiment that illustrate two different types of flow. He used to inject a thin stream of colored
fluid into a long water flowing glass tube. Reynold noticed that if the volume and dimeter or both
are small and the viscosity is large; Re will be small and in this case the fluid flow becomes
laminar. Increasing dimeter or volume or decrease the viscosity cause Re to increase (Taneda,
1956). The fluid flow in a pipe line (closed conduit) is differ from a fluid flowing in open channel
where a closed channel is at a pressure. Which a flow in a pipe line can be illustrated such as;
Laminar, Transitional, and Turbulent flow. To differentiate between above features, known as
“Reynold’s Number” can be used in order to make a good distinction. Reynold gave a number that
can be used as a boundary of flow faces which is a function of; fluid density, fluid viscosity, pipe
diameter, flow velocity (Jaafar, 2019). The flow regimes are made visible colored sight which able
to provide and illustrate the velocity image as (Figure 1), when a sight tracer appears as a straight
line the flow is laminar as (Figure. 1.a) as soon as the flow rate changes the straight line to a
turbulent which tracer spread inside the pipe cross-section (Figure 1.b) (Mattioli, 2008). According
to Osborne Reynolds, If the value of Re<2000 then the flow is laminar while Re is between 2000-
4000 it used to be a transitional and if Re>4000 it said to be Turbulent (Jaafar, 2019).
NRe= vDρ/μ or R = vD/υ ………………………………………………………..………..………(1)
Cross-Section Area: 𝐴 = 𝜋𝑟2
…………………………………………………………………...(2)
Flow rate: Q = V/t ………………………………………………………………………………..(3)
Velocity: v = Q/A ………………………………………………………………………………..(4)
1

4. Where:
NRe = Reynolds No dimension less ; μ = Dynamic viscosity, for water: 0.008817 kg/m.s ; υ =
Kinematic viscosity m2/s, for water: 10-6
m2/s ; V = Volume in m3
; D = Diameter of pipe in m ; A
= pipe area m2
; ρ = Density kg/m3
; t = time in seconds ; Q = flow rate in m3
/s.
Figure 1. Type of Fluid Flows. In (a) the flow is laminar. In (b) the flow is turbulent. In (c) the
transition from laminar to turbulent motion is seen in detail, with the formation of curls in the
tracer before the mixing with the other fluid becomes complete (Mattioli, 2008).
2

5. Apparatus and Materials
Materials:
• Water.
• Blue Ink: Is a martial used to indicate and show type of flow in a water which has a different
density. Shown at Figure 2.
Apparatus:
• Reynolds Apparatus: Is a device used to show and determine type of flow of a fluid in
different flow rates. See Figure 3.
• Graduated Cylinder: Used to determine the volume of water. Shown in Figure 4.
• Stopwatch: Used to determine flowing time to the graduated cylinder. See Figure 5.
3
Figure 2. Blue ink. Figure 3. Reynolds Apparatus
Figure 4 Graduated cylinder. Figure 5. Stopwatch

6. Procedure
1. Fill the ink tube with blue ink.
2. Now lower the ink injector till it seen in the glass tube.
3. Connect the water tank to a water source to making sure that the water level stays
constant in water tank.
4. Now open the water valve with dye valve and let the ink or dye leak to the glass tube
until the slow flow is achieved.
5. Bring a graduated cylinder and set a timer when a cylinder gets filled with water.
6. Let a cylinder filled in water to any volume while the timer is running.
7. Stop the timer with closing the outlet valve.
8. Record the time and volume of water in cylinder.
9. Repeat the same procedure 5 more times for different type of flow by controlling the
valve.
4

7. Calculation
5

8. Result and Discussion
Table 1: Experimental and Theorical Results.
Trail
No.
Volume of Water
(cc)
Time
(sec)
Volumetric Flow
Rate (m3/s)
Reynold’s No. Flow Type
1 85 6.08 1.39x10-5
146.88 Laminar
2 105 2.81 3.73x10-5
415.81 Laminar
3 70 11.18 6.26x10-5
70 Laminar
4 135 7.06 1.912x10-5
212.78 Laminar
5 107 10.28 1.04x10-5
115.82 Laminar
6 109 6.81 1.6x10-5
178.11 Laminar
Regarding to the (Table 1.) each trail number has measured its volume at a certain period of time
using a timer and graduated cylinder. The calculation for volumetric flow rate has to be first
calculated using Equ.3. while the volume has changed to m3 from a cubic centimeter. The Reynold
No. can be calculated using Equ.1. by putting the value of each density of water in kg/m3, µ of
water, diameter of tube, and the fluid velocity which can be calculated from Equ.4. by dividing the
flow rate over the cross-section area of the tube using the Equ.2. And the fluid types can be
recognized using Reynold number range of fluid types which the results were NRe less than 2000
that indicates that all fluids have laminar trace.
Conclusion
Reynolds number indicates that the type of fluid flow can take three form of Laminar, Transitional,
and Turbulence depending on the density of the fluid, viscosity, pipe diameter, and flow velocity.
Which can be experimentally tested on Reynolds apparatus.
6

9. References
Franco, M. (2005). The Reynolds experiment Chapter 13. Bologna: University of Bologna, pp.97-
99.
Maatooq, J. (2019). Flow Dynamics in Closed Conduit (Pipe Flow). uotechnology.edu.iq, pp.1-2.
Sadatoshi Taneda, (1956): Experimental Investigation of the Wake behind a Sphere at Low
Reynolds Numbers; Journal of the physical society of japan, vol. 11, no. 3, pp. 1104-1108.
7