Page 1 of 7
European Journal of Business &
Social Sciences
Available at https://ejbss.org/
ISSN: 2235-767X
Volume 07 Issue 04
April 2019
Available online:https://ejbss.org/ P a g e | 1285
EXPERIMENTAL INVESTIGATION OF HEAT TRANSFER
CHARACTERISTICS WITH NANOFLUIDS
JESURAJAN .J
PG Student,
PRIST Deemed to be University, Thanjavur
Abstract – Heating and cooling are two important processes in
thermal engineering and play a vital role in industries such as
power plants, chemical process plants, manufacturing
processes, automotive and electronics. Conventional heat
transfer fluids like water, oil, and glycols have poor heat
transport capabilities and they hardly meet the present-day
requirements of high heat dissipation rates in compact heat
exchangers. The aim of the present experimental work is to
study the heat transfer characteristics of an antifreeze water- propylene glycol based CuO nanofluids flowing in a tube,
under constant heat flux boundary conditions in laminar and
transition flow regimes. The use of inserts with nanofluids to
further compound the heat transfer enhancement is a new
technique.
Keywords- Nano fluids, heat exhanger, CuO
I. Introduction
Nanotechnology is one of the emerging areas to be
explored and attracting the attention of researchers and
academicians round the globe. Nanotechnology has brought
in many transformations in the fields of engineering and
medicine and has influenced the life style of present-day
generation. Due to reliable operation i.e. lower fuel
consumption and better power performance, the
compression ignition engines are considered as prime
movers in light, medium and heavy duty applications such
as automobiles power plants, marine, Industrial and
agricultural sectors. n the recent years, nano technology is
profoundly influencing many facets of every day life.
Presence of nano materials are seen in many fields which
include alternative energies, medical, cosmetic,
biotechnology, bioinformatics, agriculture, food industries
and information technology so on and so forth. In the field
of energy nano materials are used in solar cells, in fuel cells
and for storage of hydrogen energy. Nano-coated surfaces
are used to achieve higher transmissivity which increases
the performance of solar collectors. Nanomaterials can also
be used in medical diagnosis and drug delivery systems.
Scratch free surfaces with wear and corrosion resistant
properties are made by employing nanoparicles. The
nanomaterials also used in the manufacture of nano
composites for light weight structures in aerospace
applications. Sintered Tungsten and Titanium carbide tools
which give better mechanical properties in hard cutting
applications are manufactured using metallic powders in
nano size.
Now a days, nano materials are being widely used in the
manufacture of new generation sporting goods, computer
chips, cosmetics and sun creams.
Heat transfer is an important area of study in thermal
engineering. Selection of a suitable heat transfer fluid for
heat dissipation is an important consideration in the thermal
design of heat exchangers. Heat transfer fluid is one of the
critical parameters which affect the cost and size of heat
exchangers systems. Conventional fluids like water and oils
have limited heat transfer capabilities.
The need for development of new kinds of fluids with
improved heat transfer capabilities is being felt by different
research groups across the world. The advances in
nanotechnology have made it possible to manufacture metal
and metal oxides particles on nano dimensional scale. Nano
particles are considered to be new generation material having
potential applications in the heat transfer area.
Page 2 of 7
European Journal of Business &
Social Sciences
Available at https://ejbss.org/
ISSN: 2235-767X
Volume 07 Issue 04
April 2019
Available online:https://ejbss.org/ P a g e | 1286
II. Preparation of Nano Fluids
The amount of CuO nanoparticles required for
preparation of nanofluids is calculated using the law of
mixture formula. A sensitive balance with a 0.1mg
resolution is used to weigh the CuO nanoparticles very
accurately.
The weight of the nanoparticles required for
preparation of 100 ml CuO nanofluid of a particular
volume concentration, using water-propylene glycol base
fluid is calculated by using the following relation
The amount of CuO nanoparticles required to
prepare nanofluids of different percentage volume
concentration in a 100 ml of base fluid is summarized
in the Table3.1 shown below.
Table 1. Volume concentrations of CuO nanoparticle with
corresponding weight
The CuO nano particles having an average size of 50
nm and density of 6.3 gm/cm3
is procured from a USA
based company (Sigma-Aldrich Chemicals Private Ltd) and
is used for investigation in the present experimental work.
The photographic view of the nanoparticles as seen by the
naked eyes is shown in the Fig.1.
Fig.1.Photographic view of CuO nanoparticles
The distribution of CuO nanoparticles at nano scale
can be observed under a Scanning electron microscope
(SEM). The SEM images of CuO nanoparticles at 1 μm
magnifications is shown in Fig.2(a) and SEM image of
CuO nanoparticle on a 500 nm scale is shown in Fig.2(b).
A stable nanofluid with uniform particle dispersion is
required and the same is used for measuring the thermo
physical properties of nanofluids.
(a) (b)
Fig.2 SEM images of CuO nanoparticles on
1μm and 500 nm scales
In this method, the nanoparticles are directly mixed
in the base liquid and thoroughly stirred. Nanofluids
prepared in this method give poor suspension stability,
because the nanoparticles settle down due to gravity, after
a few minutes of nanofluid preparation. The time of
particle settlement depends on the type of nanoparticles
used, density and viscosity properties of the host fluids.
By acid treatment of base fluids : The PH value
of the base fluid can be lowered by adding a suitable acid
to it. A stable Nanofluid with uniform particle dispersion
can be prepared by mixing nanoparticles in an acid treated
base fluid. But acid treated nanofluids may cause corrosion
on the pipe wall material with prolonged usage of
nanofluids. Hence acid treated base fluids are not preferred
for preparation of Nanofluids even though formation of
stable nanofluids is possible with such base fluids.
By adding surfactants to the base fluid :
In this method a small amount of suitable
surfactant, generally one tenth of mass of nanoparticles,
is added to the base fluid and stirred continuously for
few hours. Nanofluids prepared using surfactants will
Page 3 of 7
European Journal of Business &
Social Sciences
Available at https://ejbss.org/
ISSN: 2235-767X
Volume 07 Issue 04
April 2019
Available online:https://ejbss.org/ P a g e | 1287
give a stable suspension with uniform particle
dispersion in the host liquid. The nanoparticles remain
in suspension state for a long time without settling
down at the bottom of the container. After estimating
the amount of nanoparticles required for preparation of
CuO Nanofluid for a given volume concentration using
Eq. (3.1), nanoparticles are mixed in the base fluid of
water-Propylene glycol mixture. In the present
investigation, neither surfactants nor acid are added in
the CuO nanofluids, because with the addition of
surfactants the thermo physical properties of nanofluids
are affected.
Addition of acid may damage the tube material
because corrosion takes place after a few days with the
prolonged usage of such nanofluids in practical
applications. Copper oxide nanofluids of five different
volume concentrations in range of 0.025, 0.1, 0.4, 0.8,
and 1.25 % are prepared for measuring the temperature
dependent thermal conductivity and viscosity of all the
nanofluids concentration considered in the present
work. Normally agglomeration of nanoparticles takes
place when nanoparticles are suspended in the base
fluid. All the test samples of CuO nanofluids used
subsequently for estimation of their properties were
subjected to magnetic stirring process followed by
ultrasonic vibration for about 5 hours. The CuO
nanofluids samples thus prepared are kept for
observation and no particle settlement was observed at
the bottom of the flask containing CuO nanofluids even
after four hours.
Fig.3. Water-Propylene glycol (70%-30% by volume)/ CuO
Sample nanofluid
the present experiments with CuO nanofluids, the time
taken to
complete the experiment for property estimation is less
than the time required for first sedimentation to take place
and hence surfactants are not mixed in the CuO
nanofluids. The CuO nanofluids prepared are assumed to
be an isentropic, Newtonian in behavior and their thermo
physical properties are uniform and constant with time all
through the fluid sample.
II.Heat Transfer Experimental Setup And Procedure
The aim of the present experimental investigation is
to estimate heat transfer coefficient and friction factor of
CuO nanofluids. To carryout the experiments, three
different CuO nanofluids in the volume concentration of
0.025%, 0.1% and 0.5% are carefully prepared using an
anti-freezing water and propylene glycol (70:30 by volume
percent) blend as the base fluid. The photographic view of
base fluid and CuO nanofluids are shown in the Fig.4.
Stable nanofluids in required quantity are prepared.
Fig.4. Photographs showing preparation of base fluid and
CuO nanofluids
The experimental set up is designed and fabricated to
conduct experiments using the base fluid as well as CuO
nanofluids of all the three volume concentrations and by
allowing the fluids to flow in a circular plain tube.
The objective of the present experimental investigation is to
study heat transfer coefficient and friction factor
characteristics of base fluid and CuO nanofluids both in
laminar flow and transition flow regimes under constant
heat flux boundary conditions. The schematic diagram of
