EXPERIMENTAL INVESTIGATION IN A CIRCULAR TUBE WITH A SHORT-LENGTH TWISTED TAPE INSERT USING LIQUID NANOFLUIDS

1. EXPERIMENTAL INVESTIGATION IN A CIRCULAR TUBE
WITH SHORT-LENGTH TWISTED TAPE INSERT USING
LIQUID NANOFLUIDS
1
Prepared by:
Ali Hussein Kareem
Alaa Ahmed kidder
Abbas falah shahi
Ali Hussein Jassim Hayyouk
Samir Obaid Omran
Karar Jawad Kazem
Supervised by :
Asst.Prof.Dr Azher
M.Abed

2. PRESENTATION OUTLINE
MUNICIPALITIES ENJOY
FINANCIAL AND ADMINISTRATIVE
AUTONOMY
1. Introduction
2. Objectives
3. Literature Review
4. Methodology
5. Results and Discussion
6. Conclusions
7. Recommendations for Future Work
2

3. 1. Introduction
1.1. The Background…
For greater economy and efficiency: TTHE + NF
• TTHE: Twisted Tape geometry is one of the many suitable techniques to
enhance the heat transfer in heat exchangers.
• NF: Modern nanotechnology has enabled the production of metallic or
nonmetallic nanoparticles with average crystallite sizes below 100 nm. Mixing
nanoparticles in fluids creates Nanofluids.
3

4. 1.2 The Problem Statement
 Designing heat exchangers is required to increase the energy saving.
 Reductions in tube dimensions are accompanied by higher pressure drop .
 Conventional coolants are inherently poor heat transfer fluids.
 The use of traditional heat transfer fluids in Twisted tape limits its potential –
due to low thermal conductivity.
 Improvements of the twisted tape geometry with aims to reduce the friction
factor and increase a thermal performance factor.
 SOLUTION
 Using twisted tape geometry is a suitable method to increase the thermal
performance and provide higher compactness.
 Relook at the HT fluids used. This is where NF comes in.
However, the use of NF in TTHE-devices is a totally new field of research,
which is gaining attention lately.
 Most studies focus on certain areas, not much done on the overall performance
of devices. Few research papers were found on TTHE + NF.
 Performance analyses is important for the evaluation of the net energy gain .
1. Introduction
4

5. 2. Objective
5
- To study the effects of the geometrical shape of twisted
tape inserts on the friction factor, Nusselt number and
thermal enhancement factor.
- To study the effect of using SiO2 liquid Nano fluid on the
thermal on flow field over twisted .
- To examined different mass flow rate and different heat
flux with water and Nano fluids on the thermal and flow
field.

6.  Twisted Tape Inserts :
3. Literature Review
• some recent papers available, but using conventional fluids.
 Nanofluids :
• New field of research, the numerous experimental and theoretical studies
have been reported on the properties of the fluids.
• No data as reported previously on the heat transfer and flow characteristics
in the Twisted Taps inserts using nanofluids.
 Thus, the present study aim to :
• Experimental investigation in Twisted Taps inserts using the common fluid
through this geometry.
• Study experimentally the convective flow and heat transfer of SiO2
nanofluids in the Twisted Taps inserts in the horizontal tube .
6

7. 4. Research Methodology
 CFD is used as a design tool, especially for the purposes of design
optimization, process optimization and parametric study.
 due to the high cost and time consume for experimental method
 CFD was chosen as the method of choice for this research because:
The steps of solution are involved:
 Introduction.
 Literature review.
 Physical model + Set the B.C. and assumptions.
 Numerical Computation
 Mesh generation + Grid Independence Test.
 Code validation of CFD.
 fluid Thermophysical properties
 Numerical simulation + results + conclusions + recommendations
7

8. 4. Research Methodology
 The physical model:
The schematic diagrams of the present problem are shown below , which consisted of a
two symmetric corrugated plate.
(a)
Fig.1: Schematic Diagram of the twisted tape: (a) Physical Model for pipe with
short-length twisted l, (b) Investigated Domain.
(b)
8

9. 4. Research Methodology
The details of the geometry are listed in following table :
9

10. 4. Research Methodology
 Mesh generation :
The grid independence test is carried out in the analysis by adopting different
grid distributions of 24000, 34000, 48000 and 88000. The grid independence test
indicated that the grid systems of 48000 ensure a satisfactory solution .
 Numerical Computation :
The control volume method, SIMPLEC algorithm is used to deal with the
problem of velocity and pressure coupling. Second – order upwind scheme and
structure uniform grid system are employed to discretize the main governing
equation .
Schematic Diagram of the Structured
Uniform Grid System
No of Grid
Average
Nusselt
Number
25000 50000 75000
200
225
250
275
300
325
350
375
400
Heat flux =3 kW/m2
Height of channel (Hmin) = 12.5 mm
Wavy angle (40°)
Frame 001  22 Jul 2012 
Frame 001  22 Jul 2012 
Grid Independence Test Results
10

11.  Code Validation
4. Research Methodology
TEST 1. Naphon (numerical) Comparison of the average corrugated plate
temperature and average Nusselt number for different Reynolds numbers is
shown below:
Reynolds Number
Average
Corrugated
Plate
Temperature
(c°)
600 800 1000 1200 1400 1600
0
20
40
60
80
100
wavy angle (40°) Naphon
wavy angle (40°) Present study
Heat Flux = 1.08 kW/m2
Frame 001  22 Jul 2012  | | |
Frame 001  22 Jul 2012  | | |
Comparison of the Average Corrugated Plate
Temperature for Different Reynolds Numbers
Reynolds Number
Average
Nusselt
Number
600 800 1000 1200 1400 1600
0
5
10
15
20
25
30
35
40
wavy angle (40°) Naphon
wavy angle (40°) Present study
Heat Flux = 0.58 kW/m2
Frame 001  22 Jul 2012  |
Frame 001  22 Jul 2012  |
Comparison of the Average Nu for Different Re.
11

12. 4. Research Methodology
TEST 2. Naphon (experimental) the predicted results obtained from the
present model are consistent with the experimental data and lie within ∓10%
is shown below:
Reynolds Number
Average
Nusselt
Number
1000 2000 3000 4000 5000 6000 7000 8000
0
10
20
30
40
50
Wavy angle (20°) Naphon
Wavy angle (40°) Naphon
Wavy angle (60°) Naphon
Wavy angle (60°) Present study
Wavy angle (40°) Present study
Wavy angle (20°) Present study
Hear flux =1.09 Kw/m2
Heigh of channel =2 cm
Frame 001  22 Jul 2012  | | | | | | | |
Frame 001  22 Jul 2012  | | | | | | | |
Comparison of the Average Nu for Different Re and Different Wavy Angles.
12

13. 4. Research Methodology
 NF properties were determined using the
following equations:
 Density
 Heat
capacity
 Thermal
conductivi
ty
 Viscosity
 NF properties for various types of nanoparticles
at Ø =4% and dp=20 nm.
NF

(kg/m3)
Cp
(J/kg.K)
k
(W/m.K)
µ
(mpa s)
Al2O3 1100 3734 0.7170 1.64
CuO 1216.6 3400 0.7295 1.64
SiO2 1040 3890 0.6410 1.64
ZnO 1180 3480 0.7154 1.64
13

14. 5. Results & Discussion
 The Effect of Single V-shape Channel and Straight Channel
Reynolds Number
Average
Nusselt
Number
5000 10000 15000 20000 25000
0
50
100
150
200
250
300
Wavy angle (20°)
Straight channel
Heat flux = 3 kW/m2
Channel height (Hmin) = 7.5 mm
Hw = 2.5 mm
Frame 001  22 Jul 2012  | | | | | |
Frame 001  22 Jul 2012  | | | | | |
Variation of Average Nu and Pressure Drop Per unit Length with Reynolds Number
Reynolds Number
Pressure
Drop
Per
unit
Length
(Pa/mm)
5000 10000 15000 20000 25000
0
1
2
3
4
5
Wavy angle (20°)
Straight channel
Heat flux =3 kW/m2
Height of channel (Hmin) = 7.5 mm
Hw = 2.5 mm
Frame 001  22 Jul 2012  | | | |
Frame 001  22 Jul 2012  | | | |
14

15. 5. Results & Discussion
 Effect of Wavy Angle
Variation of Average Nu with Re for Different Wavy Angles
Reynolds Number
Average
Nusselt
Number
5000 10000 15000 20000 25000
0
50
100
150
200
250
300
Wavy angle (60°)
Wavy angle (40°)
Wavy angle (20°)
Heat flux = 3 kW/m2
Channel height (Hmin) = 7.5 mm
Hw = 2.5 mm
Frame 001  26 Jul 2012  | | | | | |
Frame 001  26 Jul 2012  | | | | | |
Reynolds Number
Average
Nusselt
Number
5000 10000 15000 20000 25000
0
50
100
150
200
250
300
Wavy angle (60°)
Wavy angle (40°)
Wavy angle (20°)
Heat flux =3 kW/m2
Channel height (Hmin) = 7.5 mm
Hw = 3.5 mm
Frame 001  26 Jul 2012  | |
Frame 001  26 Jul 2012  | |
Reynolds Number
Average
Nusselt
Number
5000 10000 15000 20000 25000
0
50
100
150
200
250
300
Wavy angle (60°)
Wavy angle (40°)
Wavy angle (20°)
Heat flux =3 kW/m2
Height of channel (Hmin) = 7.5 mm
Hw = 4.5 mm
Frame 001  26 Jul 2012  | |
Frame 001  26 Jul 2012  | |
15

16. 5. Results & Discussion
 Effect of Wavy Angle
Variation of Pressure Drop per unit Length with Re for Different
Wavy Angles.
Reynolds Number
Pressure
Drop
Per
unit
Length
(Pa/mm)
5000 10000 15000 20000 25000
0
1
2
3
4
5
Wavy angle (60°)
Wavy angle (40°)
Wavy angle (20°)
Heat flux =3 kW/m2
Height of channel (Hmin) = 7.5 mm
Hw = 2.5 mm
Frame 001  26 Jul 2012  | | | |
Frame 001  26 Jul 2012  | | | |
Reynolds Number
Pressure
Drop
Per
unit
Length
(Pa/mm)
5000 10000 15000 20000 25000
0
0.25
0.5
0.75
1
1.25
1.5
1.75
2
Wavy angle (60°)
Wavy angle (40°)
Wavy angle (20°)
Heat flux =3 kW/m2
Height of channel (Hmin) = 7.5 mm
Height of wavy = 3.5 mm
Frame 001  26 Jul 2012  | |
Frame 001  26 Jul 2012  | |
Reynolds Number
Pressure
Drop
Per
unit
Length
(Pa/mm)
5000 10000 15000 20000 25000
0
1
2
3
4
5
Wavy angle (60°)
Wavy angle (40°)
Wavy angle (20°)
Heat flux =3 kW/m2
Height of channel (Hmin) = 7.5 mm
Hw = 4.5 mm
Frame 001  26 Jul 2012  | |
Frame 001  26 Jul 2012  | |
16

17. 5. Results & Discussion
 Effect of Wavy Angle
Performance at Different Wavy Angles
Reynolds Number
J/f
5000 10000 15000 20000 25000
0
0.1
0.2
0.3
0.4
0.5
Wavy angle (60°)
Wavy angle (40°)
Wavy angle (20°)
Heat flux =3 kW/m2
Height of channel (Hmin) = 7.5 mm
Height of wavy = 2.5 mm
Frame 001  26 Jul 2012  | |
Frame 001  26 Jul 2012  | |
Reynolds Number
J/f
5000 10000 15000 20000 25000
0
0.1
0.2
0.3
0.4
0.5
Wavy angle (60°)
Wavy angle (40°)
Wavy angle (20°)
Heat flux =3 kW/m2
Height of channel (Hmin) = 7.5 mm
Height of wavy =3.5 mm
Frame 001  26 Jul 2012  | |
Frame 001  26 Jul 2012  | |
Reynolds Number
J/f
5000 10000 15000 20000 25000
0
0.1
0.2
0.3
0.4
0.5
Wavy angle (60°)
Wavy angle (40°)
Wavy angle (20°)
Heat flux =3 kW/m2
Height of channel (Hmin) = 7.5 mm
Height of wavy =4.5 mm
Frame 001  26 Jul 2012  | |
Frame 001  26 Jul 2012  | |
17

18. 5. Results & Discussion
 Effect of Wavy Angle
Streamlines (left) Isotherms (right) for Different Wavy Angles at
Re=12000, Hw=3.5mm, Hmax=15,Hmin=7.5.
18

19. 5. Results & Discussion
 Effect of Wavy Height
Variation of Average Nu with Re for Different
Hw.
Reynolds Number
Average
Nusselt
Number
5000 10000 15000 20000 25000
0
50
100
150
200
250
300
Hw=4.5 mm
Hw=3.5 mm
Hw=2.5 mm
Heat flux =3 kW/m2
Height of channel (Hmin) = 7.5 mm
Wavy angle (60°)
Frame 001  26 Jul 2012  | |
Frame 001  26 Jul 2012  | |
Reynolds Number
Pressure
Drop
Per
unit
Length
(Pa/mm)
5000 10000 15000 20000 25000
0
1
2
3
Hw = 4.5 mm
Hw = 3.5 mm
Hw = 2.5 mm
Heat flux =3 kW/m2
Height of channel (Hmin) = 7.5 mm
Wavy angle (60°)
Frame 001  26 Jul 2012  | |
Frame 001  26 Jul 2012  | |
Variation of Pressure Drop with Re for
Different Hw .
19

20. 5. Results & Discussion
 Effect of Wavy Height
Variation of Heat Transfer Enhancement with
Re at Wavy Angle 60°.
Effect of Wavy Height on the Performance
Reynolds Number
J/f
5000 10000 15000 20000 25000
0
0.1
0.2
0.3
0.4
0.5
Hw = 2.5 mm
Hw = 3.5 mm
Hw = 4.5 mm
Heat flux =3 kW/m2
Height of channel (Hmin) = 7.5 mm
Wavy angle (60°)
Frame 001  26 Jul 2012  | |
Frame 001  26 Jul 2012  | |
Reynolds Number
Nu-corr/
Nu-stra
5000 10000 15000 20000 25000
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Hw = 4.5 mm
Hw = 3.5 mm
Hw = 2.5 mm
Heat flux =3 kW/m2
Height of channel (Hmin) = 7.5 mm
Wavy angle (60°)
Frame 001  26 Jul 2012  | |
Frame 001  26 Jul 2012  | |
20

21. 5. Results & Discussion
 Effect of Channel Height
Variation of Average Nu with Re for Different
Channel Heights.
Variation of Pressure Drop with Re for
Different Channel Heights.
Heat flux = 3 kW/m2
Wavy angle (60°)
Hw = 2.5 mm
Reynolds Number
Average
Nusselt
Number
5000 10000 15000 20000 25000
0
50
100
150
200
250
300
Hmax =17.5 mm
Hmax =15 mm
Hmax =12.5 mm
Frame 001  26 Jul 2012  | |
Frame 001  26 Jul 2012  | |
Reynolds Number
Pressure
Drop
Per
unit
Length
(Pa/mm)
5000 10000 15000 20000 25000
0
1
2
3
Hmax=12.5 mm
Hmax=15 mm
Hmax= 17.5 mm
Heat flux =3 kW/m2
Wavy angle (60°)
Hw = 2.5 mm
Frame 001  26 Jul 2012  | |
Frame 001  26 Jul 2012  | |
21

22. 5. Results & Discussion
 Effect of Channel Height
Effect of Channel Height on the Performance
Reynolds Number
J/f
5000 10000 15000 20000 25000
0
0.1
0.2
0.3
0.4
0.5
Hmax =17.5 mm
Hmax =15 mm
Hmax =12.5 mm
Heat flux =3 kW/m2
Wavy hieght = 2.5 mm
Wavy angle (60°)
Frame 001  26 Jul 2012  | |
Frame 001  26 Jul 2012  | |
22

23. 5. Results & Discussion
 Effect of Heat Flux
Variation of Corrugated Surface Plate Temperature with Re for
Different Heat Flux
Reylonds Number
Ts,ave(
K
)
5000 10000 15000 20000 25000
299.9
300
300.1
300.2
300.3
300.4
300.5
300.6
300.7
300.8
300.9
Heat flux = 6 Kw/m²
Heat flux = 3 Kw/m²
Heat flux = 0.4 Kw/m²
Wavy angle = 60°
Inlet water temperture = 300 K
Hmax = 17 mm
Frame 001  26 Jul 2012  | | |
Frame 001  26 Jul 2012  | | |
23

24. 5. Results & Discussion
 The Effect of Different Nanoparticles Types
Reylonds Number
Average
Nusselt
Number
5000 10000 15000 20000 25000
100
150
200
250
SiO2
Al2O3
ZnO
CuO
Water
Volume fraction =0.04
Nanoparticle diameter =20 nm
Frame 001  26 Jul 2012  | | | | |
Frame 001  26 Jul 2012  | | | | |
Reynolds Number
Pressure
Drop
(
pa
)
5000 10000 15000 20000 25000
0
25
50
75
100
125
150
SiO2
Al2O3
ZnO
CuO
Water
Volume fraction =0.04
Nanoparticle diameter =20 nm
Frame 001  26 Jul 2012  | | | |
Frame 001  26 Jul 2012  | | | |
24

25. 5. Results & Discussion
Effect of Volume Fraction on the Nu at Various
Re.
Reynolds Number
Average
Nusselt
Number
5000 10000 15000 20000 25000
100
150
200
250
Volume Fraction =0.04
Volume Fraction =0.03
Volume Fraction =0.02
Volume Fraction =0.01
Volume Fraction =0.0
SiO2 - Water
Frame 001  26 Jul 2012  | | | |
Frame 001  26 Jul 2012  | | | |
Reynolds Number
Pressure
Drop
(
pa
)
5000 10000 15000 20000 25000
0
25
50
75
100
125
150
Volume fraction = 0.04
Volume fraction = 0.03
Volume fraction = 0.02
Volume fraction = 0.01
Volume fraction = 0.0
SiO2-Water
Frame 001  26 Jul 2012  | | | |
Frame 001  26 Jul 2012  | | | |
 The Effect of Different Nanoparticles Volume Fractions
Effect of Volume Fraction on the pressure drop
at Various Re.
25

26. 5. Results & Discussion
 The Effect of Different Nanoparticles Diameters
Average Nu Versus Re of Different Nanoparticle
Diameters.
Average Nu Versus Re of Different
Nanoparticle Diameters.




Reynolds Number
Average
Nusselt
Number
5000 10000 15000 20000 25000
100
150
200
dp =20 nm
dp=40 nm
dp=55 nm
dp=70 nm

SiO2-Water
Volume fraction =4%
Frame 001  26 Jul 2012  | | |
Frame 001  26 Jul 2012  | | |




Reynolds Number
Pressure
Drop
(
pa
)
5000 10000 15000 20000 25000
0
25
50
75
100
125
150
dp=20 nm
dp=40 nm
dp=55 nm
dp=70 nm

SiO2-Water
Vloume fraction =4%
Frame 001  26 Jul 2012  | | |
Frame 001  26 Jul 2012  | | |
26

27. 5. Results & Discussion
 The Effect of Different Base fluids
Average Nu Versus the Re of Different Base
Fluids.
.
Pressure Drop Versus Re of Different Base
Fluids
Reynolds Number
Average
Nusselt
Number
5000 10000 15000 20000 25000
200
400
600
800
1000
SiO2 - Glycerin
SiO2 - EG
SiO2 - Water
Frame 001  26 Jul 2012  | | |
Frame 001  26 Jul 2012  | | |
Reynolds Number
Pressure
Drop
(
pa
)
5000 10000 15000 20000 25000
101
10
2
103
104
10
5
106
10
7
108
109 SiO2 - Glycerin
SiO2 - EG
SiO2 - Water
Frame 001  26 Jul 2012  | |
Frame 001  26 Jul 2012  | |
27

28. 5. Results & Discussion
 The Effect of Different Reynolds Numbers
Distribution of Local Nu for Different Re along the Corrugated
Wall
X
local
Nusselt
Number
0.00025 0.0005 0.00075 0.001
0
50
100
150
200
250
300
350
400
450
500
Re=20000
Re=16000
Re=12000
Re=8000
SiO2-Water
Volume fraction = 4%
Frame 001  26 Jul 2012  | | |
Frame 001  26 Jul 2012  | | |
28

29. 6. Conclusions
29

30. 6. Conclusions
30

31. 7. Recommendations for Future Work
 An experimental setup can be constructed to validate the numerical
results.
 Improving heat transfer coefficient of corrugated plate heat exchanger by
using other shapes of vortex generators (such as corrugated shapes with
dimpled) can be studied.
 Other values of wavy angles can be chosen to be investigated.
 This study could be extended to other types of nanoparticles such as
CNT, SiC and SiN.
 A numerical study of three-dimensional of corrugated plate heat
exchanger of turbulent flow can also be done.
31

32. THANK YOU
32