The Deposition of Nanoparticles on Heat Transfer Surfaces
Purdue University Calumet
School o f
T e c h n o l o g y
The Deposition of Nanoparticles on Heat Transfer Surfaces
In partial fulfillment of the requirements for the
Degree of Master of Science in Technology
A Directed Project
By
Sultan Alanazi
May 03, 2011
Committee Member
Approval Signature
Date
Lash Mapa, Chair
_______________________________________
____________
Mohammed A. Zahraee
_______________________________________
____________
Craig Engle
_______________________________________
____________
1
The Deposition of Nanoparticles on Heat Transfer Surfaces
Table of Contents
Description
Page #
1. Abstract
3
2. Introduction
4
3. Problem Statement
7
4. Significance of the Problem
8
5. Purpose of the project
9
6. Definitions
10
7. Delimitations
11
8. Limitations
12
9. Literature Review
13
10. Equipment and Procedures
22
10-1) Experiment Design
22
10-2) Experiment Parameters
22
10-3) Calculations to Determine the Gage of Nichrome wire
22
10-4) Equipment
23
10-5) Heating Element Fabrication
25
10-6) Experiment set up
26
10-7) Nanofluid Preparations
27
10-8) Experiment Procedures
28
10-9) Data Collection
28
10-10) Data Analysis
40
10-11) Experiment Errors
41
11. Conclusions and Recommendations
42
12. References
44
13. Appendix
46
2
The Deposition of Nanoparticles on Heat Transfer Surfaces
1. Abstract
Nanofluids have been seriously studied to work as a heat transfer medium during the past few
decades. Nanoparticles are a microscopic particle with at least one dimension less than 100 nm.
Nanofluid is a mixture of nano-sized particles of less than 100 nm suspended in liquid medium.
Currently, the research focused on substituting heat transfer nanofluid in industrial applications.
Some researchers state that addition of nano-particles to base fluid will increase the thermal
conductivity by as much as 160%. This project focuses on the deposition of nano-particles of
different concentrations on the heat transfer surfaces. In this project, a series of experiments will
be performed to obtain the heat transfer advantage of using nanofluids instead of water. The
variables in this research are the different types of nanoparticles at different concentrations in the
base fluid which is water. The research attempts to develop a model to observe the change of the
Critical Heat Flux (CHF) in different nanofluids concentrations and various temperatures.
3
The Deposition of Nanoparticles on Heat Transfer Surfaces
2. Introduction
In industrial applications, boiling is commonly used to transfer heat. Water is the most
commonly used liquid in boiling applications since it is easily available, cheap, and safe. The
conventional heat transfer fluids have poor thermal conductivity compared to solids. In order to
improve heat transfer efficiency, techniques are required to enhance the conductivity of the
fluids. The thermal conductivity of the nanofluids is higher than the base fluid (water).
Therefore, dispersing nano-particles will enhance the heat transfer efficiency of fluids (Kevin G.
2010).
Nano-particles are particles less than 100 nm in size that increases the thermal conductivity for
any fluid after being dispersed in it. One of the most interesting properties of nanofluids is their
boiling heat transfer behavior. Experiment is necessary to investigate the heat transfer behavior
in nanofluids, will be designed in this study.
The ability of nanofluids to increase the efficiency of heat transfer will help in reducing the
power cost and environmental impact. Nanotechnology is a developing technology, and will help
the industry economy if the mechanism of heat transfer in nanofluids is investigated more.
There are only a few researches citation that have been directed to-date on convective and
boiling heat transfer in nanofluids. Most of these investigations exposed conflicting results.
Additional investigation is necessary to fully understand the behavior of nanofluids under boiling
Heat Flux.
Over the past few years, the use of nanofluids in industrial applications has become more
common. The main concept of dispersing nano-particles in base fluids is to enhance thermal
4
The Deposition of Nanoparticles on Heat Transfer Surfaces
conductivity and its history can be traced back to Maxwell in the 19th century (Eapen, J. 2007).
Since then, the research in critical Heat Flux (CHF) of nanofluids has been of interest to the
scientists working on nano-particles.
The nano-particles that are commonly used in heat transfer area include metal oxides alumina,
Titanium, copper, etc. To investigate the deposition of nanoparticles on solid surface during heat
transfer, a nichrome wire will be used.
The following properties of nichrome make it a more suitable candidate for this purpose:

Electrical Resistivity at room temperature: 1.0 x 10-6 to 1.5 x 10-6 ohm m

Thermal Conductivity: 11.3 W/moC

Magnetic Attraction: None

Thermal Expansion Coefficient (20oC to 100oC): 13.4 x 10-6/oC

Temperature Coefficient of Resistivity (25oC to 100oC): 100 ppm/oC

Specific Gravity: 8.4

Density: 8400 kg/m3

Melting point: 1400oC

Specific Heat: 450 J/kgoC

Modulus of elasticity: 2.2 x 1011
(Swapnil S. (2009))
The deposition of nano-particles around the heating element in each experiment run may cause
increase in heat transfer rate. This feature needs to be investigated more through this research.
5
The Deposition of Nanoparticles on Heat Transfer Surfaces
This experiment is expected to provide information regarding the observations in change in the
Critical Heat Flux (CHF) of nanofluids.
6
The Deposition of Nanoparticles on Heat Transfer Surfaces
3. Problem Statement
Water is the most common fluid which been used in heating system and boiling at industry field.
Hence, the energy cost of heating is expensive expectation which made most companies looking
for cheaper system. So, the problem is the high cost of energy consumption. Ability of nanfluids in
transfer heat better than water was determining last few decades. However, the study of nanofluids
is still at its infancy, comprising primarily in heat transfer researches. More research need to
conduct understand the deposition of nano-particles over the heating element, if its effect the heat
transfer efficiency or no. To utilize the nanofluids usefully in heat transfer applications, research is
necessary to understand and determine the deposition of nano-particles on heat transfer surfaces at
different concentrations and temperatures. Once this understanding is achieved, it should enable
the use of nanofluids at appropriate concentrations in heat transfer applications.
7
The Deposition of Nanoparticles on Heat Transfer Surfaces
4. Significance of the Problem
It’s important to know the properties of nanofluids that can affect the Critical Heat flux (CHF).
Some of these proprieties are thermal conductivity, surface tension, viscosity, density, pH, and
heat of vaporization. To obtain better CHF, it’s necessary to understand how thermal
conductivity of nano-particles affects the heat transfer efficiency. Developing a proper model
which is applicable to obtain the boiling heat transfer characteristics in nanofluids is significant.
Using readily available nanofluids determination of enhance heat transfer characteristics in
applications is possible. This understanding will result in decreasing energy costs in heat transfer
applications.
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The Deposition of Nanoparticles on Heat Transfer Surfaces
5. Purpose of the Project
The purpose of this project is to study and further understand the role of nanofluids in heat
transfer, particularly the deposition on heat surfaces. The performance of nanofluids will be
evaluated using variable nanofluids of different chemical composition and concentration during
boiling. The major variables to be studied in this project are the types of the nano-particles and the
concentration in the base fluid which is water. An experiment set up was designed and fabricated
to confidently measure heat transfer characteristics in nanofluids. The result of nanoparticles
deposition on heat transfer surface will be studied.
9
The Deposition of Nanoparticles on Heat Transfer Surfaces
6. Definitions
CuO
Copper oxide
Al2O3
Aluminum oxide
CHF
Critical heat flux
hlv
Latent heat of vaporization, [J/kg]
q”
Heat flux (kW/m2)
λ
Thermal conductivity ratio
Greek Symbols
Δ Tsat
Surface superheat: Tw-Tsat [K]
Δ
Difference
Ώ
Resistance unit, [ohm]
σ
Surface tension, [N/m]
ρ
Density, [kg/m3]
Subscripts
l
Saturated liquid
nano
Nanofluid
sat
Saturated condition
v
Saturated vapor
cp
Composite particles
np
Nanoparticles
kp
Particle thermal conductivity
k1
Liquid thermal conductivity

The particle volume fraction of the suspension
10
The Deposition of Nanoparticles on Heat Transfer Surfaces
7. Delimitations
Some of the delimitations of this study are Purity of water, type of the nano-particles. A digital
thermo cable temperature reader was used instead of normal thermocouple temperature reader to
obtain the exact reading. Nichrome wires were used to speed up the heating process and thus
avoid some common mistakes encountered during prolonged heating. Another delimitation
might be the use of a tube that houses the nichrome wire that may not fit properly. The
dispersion and deposition of nano-particles around the heating element at each experiment run
will also be delimitation.
11
The Deposition of Nanoparticles on Heat Transfer Surfaces
8. Limitations
This experiment was limited to laboratory conditions. First of all, financial limitations were our
prime concern. The fabrication was done using existing or used components. Due to cost
consideration the nanofluids use was restricted to copper oxide (CuO) and aliuminum oxide
(Al2O3).Testing was restricted to only two concentrations of nanofluids to accommodate the
time schedule.
12
The Deposition of Nanoparticles on Heat Transfer Surfaces
9. Literature Review
Nanofluids are suspensions of nanoparticles in a base fluid, typically water. The term
nanoparticle comes from the Latin prefix ‘nano’. It prefix is used to denote the 10-9 part of a
unit. In this context, nano-particles can be termed as the particles with a size in the range of a
few nanometers. Traditionally, nanoparticles have a size between 100-2500 nm. Particles
smaller than 100 nm are termed ultrafine. These objects are being extensively explored due to
their possible applications in medical, optical and electronics fields.
The most popular nano-particles that use to produce nanofluids are: aluminum oxide (Al2O3),
copper (II) oxide (CuO), copper (Cu). Water, oil, decene, acetone and ethylene glycol are the
most common base fluids being used in producing nanofluids.
“Nano-particles can be produced from several processes such as gas
condensation, mechanical attrition or chemical precipitation techniques. Gas
condensation processing has an advantage over other techniques.” (“Critical
Review of heat transfer….,” 2007)
In this project one type of nanofluids from the previous were tested. CuO and Al2O3 are
the once which is available in our lab. Water is the base fluid which will be used in this
experiment.
Preparation of a nanofluid is done by straight mixing of nano-particles with the base fluid.
Nanofluid preparation has various requirements such as an even, durable, stable suspension, low
agglomeration of particles, and no chemical change of the fluid. Following approaches have been
suggested to stabilize the suspensions of nanofluids: using ultrasonic vibration, changing the pH
13
The Deposition of Nanoparticles on Heat Transfer Surfaces
value of suspension, and using surface activators and/or dispersants. These approaches will
change the surface properties of base fluids, particularly the heat transfer characteristics. The
required application of the nanofluid will verify the type of approach needed to be used. Choice
of the appropriate activation of dispersants depends primarily on the characteristics of particles
and solutions. (“Critical Review of heat transfer….,” 2007)
Information about how nanofluids Preparation mentioned were cooperative. In our work, similar
process was followed. Analytical scale to weight the nanofluids and water volumes is needed.
Matrices beaker were used to measure the quantity of water.
Particles can break or compose after mixing into the liquid. To observe the characteristics of
particles while dispersed in liquid, Transmission Electron Microscopy (TEM) is commonly used.
Some other researchers use ultrasonic vibration techniques in watching the particles, but
ultrasonic vibration techniques can break agglomerates.
High resolution camera was our watching device to picture the deposition of nanofluids on
nichrome wire. So many pictures were taken while the experiment in running. These
observations will help in analyze the relation between depositions of nanoparticles on heat
element surface and temperature change.
Nichrome wire is the best electrical wire to be used in heating, because of its high capability of
heat storing and high resistivity. Nichrome is providing so many options of different gages and
diameters. Calculated of nichrome wire specifications were done at the experiment preparation
section of this paper.
The following properties of nichrome make it a more suitable candidate for this purpose:
14
The Deposition of Nanoparticles on Heat Transfer Surfaces
9. Electrical Resistivity at room temperature: 1.0 x 10-6 to 1.5 x 10-6 ohm m
10. Thermal Conductivity: 11.3 W/moC
11. Magnetic Attraction: None
12. Thermal Expansion Coefficient (20oC to 100oC): 13.4 x 10-6/oC
13. Temperature Coefficient of Resistivity (25oC to 100oC): 100 ppm/oC
14. Specific Gravity: 8.4
15. Density: 8400 kg/m3
16. Melting point: 1400oC
17. Specific Heat: 450 J/kgoC
18. Modulus of elasticity: 2.2 x 1011
(Swapnil S., 2009)
Water is the most commonly used solvent. It is also one of the most common base fluids used in
heat transfer applications use for boiling. It is a non-toxic and inexpensive liquid. Its low
viscosity makes it easy to pump through tunnels and pipes. But the bad part of water is that it
has a low boiling point and a high freezing point, comparatively though. Moreover, if its pH is
little away from neutral point (pH = 7), it can be corrosive (Heat Transfer Fluids…, n.d.).
The base fluid which was used in the experiment is water ether tap water or De-ionized water.
Result of nanofluids runs is going to be compared with water result.
Thermal conductivity (λ) is the intrinsic property of a material which relates its ability to conduct
heat. This means that thermal conductivity is the factor that affects heat transfer rate of each
material. Nanofluids have higher thermal conductivity than the pure liquid (water).
15
The Deposition of Nanoparticles on Heat Transfer Surfaces
Experimentally, suspending the nanoparticles was enhancing the base fluids thermal
conductivity, thus leading to high heat transfer rate.
Thermal Conductivity = heat × distance / (area × temperature gradient)
λ = Q × L / (A × ΔT)
Research has been conducted in the field of heat transfer over the past several years to improve
the use of heat transfer enhancement methods. The benefit of adding Nano-particles is a method
applied to increase the heat transfer performance of base fluids. Massachusetts institute of
technology (MIT) is one of the institutions working on this research in concentration. The field
of nanofluids with respect to heat transfer is quite new. As a new material, nanoparticles are
being used in suspension in conventional heat transfer fluids. Nanofluids are fluids having small
solid-particles suspended in them. The nanoparticles suspended in the fluids were changing the
heat transfer physical characteristics and transference properties of the base fluid. This research
was review and summarizes the recent improvements on the heat transfer characteristics of
nanofluids.
As nano-particles help in increasing the thermal conductivity of conventional fluids, many
researchers expected that nano-particles would enhance the boiling heat transfer. These studies
brought out several experimental investigations on the pool boiling characteristics of nanofluids.
Disperse Nano-particles as a chemical suspended into the base fluid is a method that can help
improve heat transfer. Enhancing the thermal conductivity is the method to improve the heat
transfer characteristics of conventional fluids. Since the nano-particles have a larger thermal
conductivity than a base fluid (water), disperse nano-particles into the base fluid is possible to
increase the thermal conductivity of that fluid. According to Visinee T. et al (2005),
16
The Deposition of Nanoparticles on Heat Transfer Surfaces
“The enhancement of thermal conductivity of conventional fluids by the
suspension of solid particles, such as millimeter- or micrometer-sized particles,
has been well known for more than 100 years.” (“Critical Review of heat
transfer….,” 2007)
However, because of some problems such as sedimentation, erosion, fouling and increased
pressure drop of the flow channel, this area has not drawn the attention and interest of
researchers. The modern advances in materials technology has made it possible to produce nanoparticles that can help in solving these problems. Nano-particles suspended in base fluids is a
new Innovative called ‘nanofluids’. These nano-particles were make changes in the thermal and
transference properties of the base fluid. The main goal of this paper is to study the result of
nanoparticles deposition on heat transfer surfaces after many times of heating.
Natural convection of small-nanoparticles dispersed fluids has been used in many industrial
applications such as chemical, food, and also in solar collectors. Absolutely, the natural
convection of nanofluids is not the same as the pure fluids. From unbalanced density distribution
of liquid due to temperature differences and the distribution of the nano-particles concentration
due to sedimentation, the natural convection of nanofluids is determined. There are not enough
studies reporting the natural convection of nanofluids with sedimentation. Putra et has presented
the experimental observations they made on the natural convection of two oxides (Al 2O3 and
CuO)–water based nanofluids inside a horizontal cylinder heated from one end and cooled from
the other. The requirements of parameters such as nano-particles concentration, nano-particles
material and geometry of the test tube were examined at steady-state surroundings. The nanoparticles concentration and the absence of stratification concentration layers were make the
17
The Deposition of Nanoparticles on Heat Transfer Surfaces
difference between convection of nanofluids and pure fluid. At same ratio, length and diameter
of tube were affecting the natural convective heat transfer of nanofluids and the base fluid. Most
of the researchers have focused on application of nanofluids as heat transfer medium for a singlephase heat transfer, taking advantage of the high thermal conductivity of nanofluids (Gilberto M.
Jr., 2005).
Obviously, the natural convective heat transfer of nanofluids was changed while increasing
Nano-particles concentration, aspect ratio of test tube, and nano-particle density. Nano-particles
size of CuO is smaller than that of Al2O3. Therefore, the drop in heat transfer rate should be
larger for Al2O3. This is because the nano-particles density of CuO is greater than that of Al2O3.
The nanofluid in the enclosure is assumed to be in single phase, that is, both the fluid and nanoparticles are in thermal equilibrium. The effect of suspended nano-particles on the heat transfer
wire will be analyzed. It was illustrated that the heat transfers rate increase as the nano-particles
volume fraction increases at any given Grashof number. The expectation of increase the
deposition of nanoparticles on heat surfaces is to increase the heat transfer rate.
The research conducted by Lee et al (1999) studied the effects of dispersing CuO and Al2O3
nanoparticles on the thermal conductivity of water and ethylene glycol. Their results confirmed
that the thermal conductivity of the nanofluids is higher than that of pure liquids. They also
reported that the thermal conductivity of ethylene glycol increased by more than 20% when CuO
nanoparticles were dispersed in it (Lee et al, 1999).
Another similar work reported an increase in the thermal conductivity of ethylene glycol by 40%
when copper nanoparticles were dispersed in it at 0.3% volume concentration (Eastman et al,
2001).
The above studies made use of spherical nanoparticles.
In another study, carbon
18
The Deposition of Nanoparticles on Heat Transfer Surfaces
nanotubes were dispersed in oil. The thermal conductivity of this nanofluid was 2.5 times
greater than that of pure oil (Choi et al, 2001).
In this experiment, we were evaluating the pool boiling of two different nanofluids, Aluminum
oxide (Al2O3) and copper oxide (CuO). We were also study the effects of heater thickness, size
and nature of nano-particles and surface roughness of the heater, on the boiling characteristic of
nanofluids. The expectation are to somewhat enhance the heat transfer characteristic during pool
boiling, and the boiling curves of nanofluids should be shifting to upper left part. The change of
the curve means that the nanofluids are absorbing more heat than water so it starts boiling faster.
Water Boiling Curve
19
The Deposition of Nanoparticles on Heat Transfer Surfaces
In case of heating nanofluids, our expectation was the boiling curve of nanofluids move a
slight to the left side. Because of the nanofluids was heat faster than water. That what will
be analyzed later in the plots of nanofluids vs. water.
“…the nano-particles deteriorated the boiling characteristics of water in the
nucleate boiling regime. But it can be pointed out that their experiments were not
tested until the critical heat flux limit was reached.” (“Critical Review of heat
transfer….,” 2007)
Experiment was investigated the boiling curve and Critical Heat Flux (CHF) for each nanofluid
and water. Our aim to observe the efficiency of heat transfer increasing by recording that the
boiling of nanofluids faster than the water. Moreover, the critical heat fluxes of nanofluids
should be extremely increased. The increasing of heat flux should be about double higher than
pure water when the particles volume fractions is greater than 0.005 g/l. Though, in this
experiment, the size of nano-particles is not definite yet.
A comprehensive study of the effect of dispersing aluminum oxide nanoparticles in water was
conducted by Gilberto M. Jr. (2005). He reported that the particles were quite stable in the fluid.
A raise in the pool boiling heat transfer was also identified.
From other researchers work, it’s evident that the thermal conductivity of nanofluids increased as
a function of thermal conductivity of nano-particle solid and the base fluid, volume fraction, the
surface area, and the shape of the nano-particles dispersed in the liquid. Currently, there are no
enough calculations on thermal conductivity effect in nanofluids.
20
The Deposition of Nanoparticles on Heat Transfer Surfaces
The Maxwell model is an old-style model for thermal conductivity. It was prepared for solid–
liquid nanofluids with relatively large particles. The effectiveness of thermal conductivity, keff is
given by the expression
Where kp is particle thermal conductivity, k1 is liquid thermal conductivity and  is the particle
volume fraction of the suspension. Maxwell’s model shows the correlation between the thermal
conductivity of suspensions and the thermal conductivity of base liquid, spherical particle, and
the volume fraction of the solid particles. In the case of non-spherical particles, thermal
conductivity of the nanofluids is also dependent upon the shape of the particles and not only on
the volume fraction of the particles.
21
The Deposition of Nanoparticles on Heat Transfer Surfaces
10. Equipment and Procedures
10-1 Experiment Design
The experimental environment should accommodate all different fluids in different
concentrations, and have the ability of supply heat energy to boil water.
10-2 Experiment Parameters
1- 17 inch length of nichrome wire
2- 40 ͦ C as starting point for timing
3- 5 AC volt and 6 Amps current
10-3 Calculations to determine the gage of nichrome wire
Given information:
Graduated Cylinder
Length= 10in
Diameter= .5in
V (Volume) = π r^2L
= 3.14 × .5^2 ×10
= 128.64 ≈ 130 CC (cubic Centimeter)
ρ= 1 g/cm3
∆u=m cp ∆T
=128.62 (1) (100-20) = 10400 J
q= ∆u/∆t = I^2×R
So, we started with 8 min. (280 S) first guess
Power q = ∆u/∆t = 10400/480 S = 21.6 W
Wire length should be 1.41 ft
22
The Deposition of Nanoparticles on Heat Transfer Surfaces
Started trying different Gages
Gage 17 was the best value to calculate
(http://wiretron.com/nicrdat.html)
R (Resistance) = Ω × L = (.3210) × (1.41) =.45 Ω
P= (5.5) ^2(.45) = 13.6 W
the Heating time is 12.74 mints
10-4 Equipment
1- Heating Element parts

Four of 2 inches of glass rode (break them down at school shop)

6 in X .5 in glass pieces.

Nichrome wire 18 gage (Ordered from Amazon.com)

Soder glass ( a glass which melt before than normal glass)
2- Two of 50 ml graduated cylinder (1”, 7”). (Borrow from chemistry Dept.)
3- Three Ring stands with clamps (Two Borrow from chemistry Dept.)
4- Wires
5- Variac (Powerstat Variable Transformer)
6-HP Multymeter
7- Stop watch
8- Digital thermo cable
9- Ammeter
10- 1400 Furnace Barnstead (Modle No= FB1415M).
23
The Deposition of Nanoparticles on Heat Transfer Surfaces
Figure 1: Graduated Cylinder
Figure 3: Ring Stand
Figure 5: Multymetter
Figure 2: Glass Rod
Figure 4: Power Stat
Figure 6: Ammeter
24
The Deposition of Nanoparticles on Heat Transfer Surfaces
10-5 Heating Element Fabrication







Started with cutting up a two pieces of glass with (6”, .5”), then sharp them a
45 degree from both sides for whole long.
Cut the soder glass on the inside glass faces size.
Sandwich the two glass pieces from inside faces with solderglass in between.
Leave them carefully inside the Furnace.
Apply the glass melting program.
Shape then insert the nichrome wire through glass channels.
Place the glass rods on the wire then hold them all with the ring stand clamps.
Figure 7: Heat element design
25
The Deposition of Nanoparticles on Heat Transfer Surfaces
10-6 Experiment Set up
3
1
2
2.0● 5.0●
1.0● +/- ●
5
●●
●●
4
●●
6
7
9
10
8
Uhy
i8
Figure 8: Experiment Set up
12345-
Power
Variac (power stat)
Ammeter
Supply board
Hp multimeter
6- 2 inch rod glass
7- Fluids (water, nanofluids)
8- Graduated cylinder
9- Glass hanger
10- Nichrome wire
26
The Deposition of Nanoparticles on Heat Transfer Surfaces
10-7 Nanofluid preparation
The two nanofluids concentrations were .5% and 1 %. .5% nanofluid was prepared by mixing
1.25 g of nanofluid in 250 ml of water and 1% nanofluid was prepared by mixing 2.5 g of
nanofluid in 250 ml of water.
.5 x 250 / 100 = 1.25 g
1 x 250 / 100 = 2.5 g
Analytical balance was used in measuring the amount of nanofluid.
Metric beaker used to measure and mix the nanofluid.
Figure 9: Copper oxide mixed in water
27
The Deposition of Nanoparticles on Heat Transfer Surfaces
10-8 Experiment Procedures
Step 1: Four different liquids (water, De-ionized, water, .5% CuO nanfluid, and
1% CuO nanofluid were available. Choose any one of them.
Step 2: Connect the electrical circuit as showed in Experiment set up. (Figure 8)
Step 3: Fill the graduated cylinder with 65 ml of liquid.
Step 4: Place the heating element inside the graduated cylinder.
Step 5: Turn on the power switch, then increase the volt and current level by using the Variac
Controller.
Step 6: when the temperature of the fluid reach 40 ͦ C start timer.
Step 7: After every 5 min. record the readings (Temp, Volts, and Current).
Step 8: After 30 min. of operation turn the power switch off.
Step 9: Let the liquid cool down to room temperature.
Step 10: Return to step 1 to continue with other fluids.
10-9 Data Collection
Power calculations
V Rms = V / √2
Power
P avg =V Rms × I Rms =
Example:
V Rms = V/ √2 = 5.44/√2 = 3.85
P= V Rms × I Rms = 3.85×6.17 = 23.74 W
28
The Deposition of Nanoparticles on Heat Transfer Surfaces
Table 1: Tap water Data
Tap Water Runs
Time
0
5
10
15
20
25
30
Run 1
40
59
72.1
83.7
90.7
93
94.4
Run 2
40
61.1
74.3
84
90.5
94.3
95.2
Run 3
40
58.3
72.2
81.7
87.1
91.6
94
AVG Tap
water
40.00
59.47
72.87
83.13
89.43
92.97
94.53
volt Avg
(Ac)
5.44
5.27
5.30
5.15
5.45
5.20
5.21
Volt
(Rms)
3.85
3.72
3.75
3.64
3.85
3.67
3.68
Current Avg
(Amps)(Rms)
6.17
6.14
6.13
5.70
6.03
6.08
6.07
Power
(watts)
23.74
22.87
22.97
20.76
23.25
22.34
22.36
Figure 10: Tap water Runs
Discussion: For the three tap water runs the readings were similar for each time period. There is
no evidence of any deposition on the wire, which is expected.
29
The Deposition of Nanoparticles on Heat Transfer Surfaces
Table 2: De-ionized water Data
De-ionized water Runs
Time
0
5
10
15
20
25
30
Run 1
40
60.5
73.9
83.5
90.1
94
95.7
Run 2
40
57.9
73.9
81.2
87.3
91.9
94.8
Run 3
40
60.5
74.1
83.5
92
95
96
AVG Deionized
Water
40.00
59.63
73.97
82.73
89.80
93.63
95.50
volt Avg
(Ac)
5.12
5.10
5.15
5.12
5.09
5.10
5.09
Volt
(Rms)
3.62
3.60
3.64
3.62
3.60
3.61
3.60
Current Avg
(Amps)
6.13
6.07
6.11
6.03
6.07
6.02
6.10
Figure 11: De-ionized water readings chat
Discussion: For all three runs of De-ionized water readings were similar for each time period.
There is no evidence of any deposition on the wire which is expected.
30
Power
(watts)
22.21
21.86
22.25
21.83
21.83
21.71
21.97
The Deposition of Nanoparticles on Heat Transfer Surfaces
Table 3: .5 % CuO nanofluid Data
Runs
Time
0
5
10
15
20
25
30
Run 1
40
59.9
73.6
83
89.7
93.4
96
Run 2
40
60.2
74.5
85.3
93.7
97.5
98.4
Run 3
40
60.08
75.7
88.9
95
97.5
98.3
AVG (1.25)
40.00
60.06
74.60
85.73
92.80
96.13
97.57
volt Avg
(Ac)
5.30
5.28
5.28
5.27
5.25
5.28
5.30
Volt
(Rms)
3.75
3.73
3.74
3.73
3.71
3.73
3.75
Current Avg
(Amps)
6.14
6.14
6.13
6.11
6.10
6.20
6.15
Power
(watts)
23.04
22.91
22.89
22.78
22.63
23.16
23.05
Figure 12: (.5%) CuO Nanofluid Readings chart
Discussion: Readings from all three .5% nanofluids runs were different from each other. Run 1
was the lowest reading and Run 3 was the highest reading. That may be due to deposition of
nanoparticles on the wire. It’s reported the deposition of nanoparticles decrease resistance to heat
transfer. However, the result obtained here show opposite results. This may be due to increase in
surfaces area of heat transfer of porous nanoparticles.
31
The Deposition of Nanoparticles on Heat Transfer Surfaces
Table 4: 1% CuO nanofluid Data
Runs
Time
0
5
10
15
20
25
30
Run 1
40
61
74.7
88
96.6
99.2
99.7
Run 2
40
61
70.4
87.2
97.8
99.4
100
Run 3
40
61.2
73.3
87.6
96.4
98.8
99.5
AVG (2.5)
40.00
61.07
72.80
87.60
96.93
99.13
99.73
volt Avg
(Ac)
5.33
5.19
5.21
5.35
5.38
5.07
5.43
Volt
(Rms)
3.77
3.67
3.69
3.78
3.80
3.59
3.84
Current Avg
(Amps)
6.35
6.20
6.17
6.33
6.35
6.33
6.43
Power
(watts)
23.93
22.74
22.76
23.95
24.13
22.71
24.67
Figure 13: (1%) CuO Nanofluid Boiling Time
Discussion: Readings from all three 1% nanofluids runs were no big different from each other.
Runs 1 and 2 were the lowest readings and Run 3 was the highest readings. That may be due to
low deposition of anaoparticels on the wire. It’s reported the deposition of nanopartiecls decrease
resistance to heat transfer. However, the result obtained here show opposite results. This may be
due to increase in surfaces area of heat transfer and because of porous nanoparticles.
32
The Deposition of Nanoparticles on Heat Transfer Surfaces
Tap, and De-ionized Water Vs. (.5%) and (1%) of CuO Nano fluids plot.
Figure 14
Discussion: Figure 14 is comparison between all different fluids average runs. 1% nanofluid
reached the 95 ͦ C in 20 mints then .5% nanofluid come next in 25 mints. Both types of water
were lower in heating than nanofluids. 1 % CuO reached 95 degree before tap water in 10 mints
and this is significant. Nanofluids have higher heat transfer rate than water due to the increase of
heat transfer surface of the wire after nanoparticles deposition.
33
The Deposition of Nanoparticles on Heat Transfer Surfaces
Table 5: Fluids boiling time of each temperature degree.
Temp
Cuo 1 %
Cuo .5 %
De-ionized
water
40
0
0
0
0
50
60
Time/min.
2.22
4.9
2.2
4.75
2.25
5
2.25
5
70
80
90
8.75
8.55
8.65
9
12.5
12.5
13.5
13.5
16
18
20.25
20.5
Figure 15: Since nanofluids have higher heat transfer rate than water. Nanofluids are going to
take shorter time in heating than water. As the experiments result recorded in this chart time of
heating for nanofluids less than water for each temperature degree. 1% naofluid reached 90
degree after 16 mint of heating while water took 20.5 to reach this degree.
34
The Deposition of Nanoparticles on Heat Transfer Surfaces
Table 6: Energy Costs
Time
0
5
10
15
20
25
30
Time
0
5
10
15
20
25
30
Tap
Water
23.74
22.87
22.97
20.76
23.25
22.34
22.36
Cent/watts
0.00935
0.00935
0.00935
0.00935
0.00935
0.00935
0.00935
Total $
0.221969
0.2138345
0.2147695
0.194106
0.2173875
0.208879
0.209066
1.4800115
.5 %
CuO
Cent/Watts Total $
23.04
0.00935
0.215424
22.91
0.00935 0.2142085
22.89
0.00935 0.2140215
22.78
0.00935
0.212993
22.63
0.00935 0.2115905
23.16
0.00935
0.216546
Deionized Cent/Waatts
Total $
22.21
0.00935 0.2076635
21.86
0.00935 0.204391
22.25
0.00935 0.2080375
21.83
0.00935 0.2041105
21.83
0.00935 0.2041105
21.71
0.00935 0.2029885
21.97
0.00935 0.2054195
1.436721
1%
CuO
Cent/Waatts Total $
23.93
0.00935 0.2237455
22.74
0.00935 0.212619
22.76
0.00935 0.212806
23.95
0.00935 0.2239325
24.13
0.00935 0.2256155
1.2847835
1.0987185
Dissection: From U.S. Energy Information website
http://www.eia.doe.gov/cneaf/electricity/epm/table5_6_a.html
Energy cost were calculated for each fluid runs. Indiana energy prices were used to done these
calculations.
9.35 (Cents per kilowatthour) = .00935 cents per Watts is the average residential cost.
This table is showing the energy prices of all fluids in the experiment. Tap and De-ionized water
were almost costing the same. However, nanofluids were costing less than water, because both of
them were taken shorter time in heating.
35
The Deposition of Nanoparticles on Heat Transfer Surfaces
Figure 16: Chart of energy cost for all Fluids
Deposition of nanoparticles on Heat Surface (Nichrome Wire)
Figure 17: High level deposition
Figure 18: Low level of deposition
36
The Deposition of Nanoparticles on Heat Transfer Surfaces
Table 7: .5% CuO Nanofluids Runs after deposition
Time
Run 1
Run 2
Run 3
Run 4
Run 5
0
40
40
40
40
5
57.6
58.1
57.5
58.7
10
69.7
69.1
70.8
71.2
15
78
77.4
78.1
79
20
83.9
83.2
82.6
82.6
25
87
85.9
85.7
86.3
30
90.1
89.8
87.8
88
Run 6
40
59.5
72.4
81
85.1
89.7
93.5
40
58.9
70.3
79
82.9
87
91
Figure 17
Discussion: The upper table and chart are records of .5% CuO nanofluid runs. Obviously,
increase in heat transfer rate after few runs. This increase might happen because of the diameter
of the wire increase due to nanoparticles deposition and the porosity of nanoparticles. So, the
surface area which involve in heat transfer was increased and this lead to increase in heat transfer
rate.
37
The Deposition of Nanoparticles on Heat Transfer Surfaces
Table 8: 1% CuO nanofluids after deposition
Time
Run 1
Run 2
Run 3
0
40
40
5
61
60.1
10
72.5
74.1
15
84.8
83.5
20
91.5
89.1
25
97
94.7
30
97.8
96.4
Run 4
40
59.9
73.2
82.5
87.3
95
97
Run 5
40
60.2
73
84.1
88
95.3
96.2
Run 6
40
60.7
74.5
84.4
90.7
94.5
97.1
40
61.5
75.2
86
95.2
98.7
99.6
Figure 18
Discussion: The upper table and chart are records of 1% CuO nanofluid runs. Obviously,
increase in heat transfer rate after few runs. This increase might happen because of the diameter
of the wire increase due to nanoparticles deposition and the porosity of nanoparticles. So, the
surface area which involve in heat transfer was increased and this lead to increase in heat transfer
rate.
38
The Deposition of Nanoparticles on Heat Transfer Surfaces
Increase in heat transfer rate after deposition was higher for 1% nanofluid rather than .5%, which
might be because of the percentage of nanofluids.
Table 8: Comparison of heating time between .5 % and 1% CuO after deposition
Temp
Cuo .5 %
Cuo 1 %
40
50
0
0
2.64
2.35
60
Time/min.
5.02
4.14
70
80
90
9.5
8.52
16.47
12.94
30
20
Figure 19: Bar chart shows the difference in the duration time of heating between .5% vs. 1%
nanofluid after deposition.
39
The Deposition of Nanoparticles on Heat Transfer Surfaces
10-10 Data Analysis
Some other researchers were documented, that the depositions of nanoparticles on heat surfaces
cause a reduction in heat transfer surfaces. Our experiment result was opposite their thoughts.
The deposition of nanoparticels on heat surface caused increase in heat transfer rate. That might
be because of:
1-Deposition of material (nanoparticals) increased the diameter of wire leads to increase the
surface area involves with heat transfer.
2-In addition, the porosity of the deposition also lends itself to increase the surface area involve
in heat transfer resulting in increase heat transfer.
3- The conductivity of the deposition may increase conduction affects assistant with heat
transfer.
A possible Explanation of No uniform disposition on heat surfaces is because of the coating
layer reach saturation. There was easy fall of particles when heating reached saturated point.
(Flat plate heater recommended because of less contact angle).
The disposition occurred during nucleat boiling due to evaporation of microlyer formed under
vapor bubble growing.
A possible Explanation of increase the heat transfer rate with the disposition is conduction
channel between the source electrode and the drain electrode, forming an insulated floating gate
for storing electric charges by passivating conductive nanoparticles
Bao H. T. (2007)
40
The Deposition of Nanoparticles on Heat Transfer Surfaces
10-11 Experiment Errors
Example types of errors
1- Measurements errors
2- Surrounding errors
3- Human errors
41
The Deposition of Nanoparticles on Heat Transfer Surfaces
11. Conclusions and Recommendations
From the above discussion, the following conclusions can be made:
1. Nanofluids are mixtures of nano-particles in base fluids, which have higher thermal
conductivity than the base fluids. Size and shape of nano-particles, the particle volume fraction,
and PH value of nanofluids, type of base fluid and nano-particles, and type of particle coating are
the factors that affect the thermal conductivity enhancement of nanofluids.
2. From our experiment result, the convective heat transfer should increase as nano-particles
volume fraction and density increases, though results of some other research experiments were
contrary to the expectations.
3. The best model to use for the thermal conductivity of nanofluids is still not clear. However, it
does need more investigations.
4. In pool boiling experiment, the addition of nano-particles to the base fluids gives more
advantage in increasing the heat flux than heat transfer rate. It can be deduced that nanofluids are
more proper for heating and cooling applications.
5. In Pool boiling CHF, using nichrome wire heater in heating nanofluids and base fluid (water)
is recommended because of its high heat storing capacity. Nichrome wire will help in drawing
the different deposition of each particle. However, nichrome wire has one disadvantage in
deposition which is falling the nanoparticles off easy.
6. Flat plate heater is recommended to have smaller contact angle, so no nanoparticles easy fall
off.
42
The Deposition of Nanoparticles on Heat Transfer Surfaces
7. Use a proper device to measure the thickness of nanoparticles deposition in future studies
(electron microscope).
Finally, there are many different areas about this research that need to be investigated and
analyzed further. Finding a method to stop losing the deposition of nano-particles on heating
element after each run is future investigation. Study a different proper heating material which
increase and save the deposition of the nanoparticles. Designing more safety model which is
appropriate for this experiment is necessary, because replacing the wire each experiment run
might cause a problem. Another future study would be to model a suitable model which keeps
experiment errors at low level.
Nanotechnology would help more in heat transfer methods, if it was getting more in depth
research.
43
The Deposition of Nanoparticles on Heat Transfer Surfaces
12. References
Average Retail Price of Electricity to Ultimate Customers by End-Use Sector, by State
(2011),Retrieved from http://www.eia.doe.gov/cneaf/electricity/epm/table5_6_a.html
Bao H. T. (2007), Determination of Pool Boiling Critical Heat Flux Enhancement in nanofluids,
Massachusetts Institute of Technology, p 8
Choi, S. U. S., Zhang, Z. G., Yu, W., Lockwood, F. E., & Grulke, E. A. (2001). Anomalous
Thermal Conductivity Enhancement in Nanotube Suspensions. Applied Physics Letters,
76, 2252-2254.
Eastman, J. A., Choi, S. U. S., Li, S., Yu, W. & Thompson, L. J. (2001). Anomalously Increased
Effective Thermal Conductivities of Ethylene Glycol-Based Nanofluids Containing
Copper Nanoparticles. Applied Physics Letters, 78, 718-720.
Frank, P. I., David, P. D., Thedore, L. B., & Adrinne, S. L. (2007). Introduction to Heat
Transfer. (5th ed.)
Gilberto M. Jr., (2005), Investigation of Pool Boiling Heat Transfer with Nanofluids, Faculty of
the Graduate School of The University of Texas; p-12
Heat-transfer fluids for solar water heating systems, US Department of Energy, Retrieved from
http://www.daviddarling.info/encyclopedia/H/AE_heat_transfer_fluid.html
Honorine A.M., Gilles R., Cong T.N., New Temperature Dependent Thermal Conductivity Data
of Water Based Nanofluids. Department of mechanical engineering, Université de
Moncton, Moncton., NB, CANADA, E1A 3E9
Kostic M., Prof. (2010), Nanofluids: Advanced Flow and Heat Transfer Fluids, Department of
Mechanical Engineering, Norther Illinois University, Available at
www.kostic.niu.edu/DRnanofluids/nanofluids-Kostic.ppt
Lee, S., Choi, S. U. S., Li, S. & Eastman, J. A. (1999). Measuring Thermal Conductivity of
Fluids Containing Oxide Nanoparticles. Transactions of ASME, 121, 280-288.L H
Martin and K C Lang 1933 Proc. Phys. Soc. 45 523 doi: 10.1088/0959-5309/45/4/304
44
The Deposition of Nanoparticles on Heat Transfer Surfaces
Nichrome 80 & Other Resistance Alloys - Technical Data & Properties, Retrieved January
30 /2011from http://wiretron.com/nicrdat.html
Kevin G., Wallace (2010), Research in Heat Transfer with Nanofluids, Department of
Technology Engineering, Purdue University Calumet.
Eapen, Jacob, Li Ju, Yipsidry, (2007), “Beyond the Maxwell limit: Thermal conduction in
nanofluids with percolating fluid structures”,physical Review E76,062501
Trisaksri, V., & Wongwises, S. (2007). “Critical Review of Heat Transfer Characteristics of
nanofluids” Department of Mechanical Engineering, King Mongkut’s university of
Technology Thonburi, Bangmod, Bangkok 10140, Thailand
Swapnil S. (2009), Properties of Nichrome Wire, Available at
http://www.buzzle.com/articles/properties-of-nichrome-wire.html
Zenghu, H. (2008). Nanofluids with Enhanced Thermal Transport Properties Retrieved January
30, 2011, from http://drum.lib.umd.edu/bitstream/1903/8654/1/umi-umd-5648.pdf
45
The Deposition of Nanoparticles on Heat Transfer Surfaces
13. Appendix
Nichrome wire Tables
Current / Temperature Table - Ni Cr A (80) & Ni Cr C (60)
46
The Deposition of Nanoparticles on Heat Transfer Surfaces
Resistance by AWG Size
47