Abstract:
In this research, the specification of 3-dimensional flow stagnation
point of hybrid Nano fluids passing through circular cylinder with
sinusoidal radius are analyzed.
C2H6O2,
H2O and Engine oil are used as an ordinary liquid, while
nano-particles include SWCNT and MWCNT. Fluid stream is taken into
account with/without considering the effect of thermal slippage. Higher
order non-linear phrases are transformed to ordinary prime-order
differential equations and then solved applying the Analytical Method
(HPM) in Matlab-14 software. Graphical analysis of the impressive
parameters like: Prandtl number, thermal slip parameter, CNTs volume
fraction is precisely checked on the profiles of velocity and
temperature for various carbon nano-tubes. Consequences display that:
cooling process or heat transfer rate can be increased by employing
smaller thermal slippage parameter. Further, due to the better thermal
conductivity of SWCNT carbon nanotube, the temperature increase in these
carbon nanotubes is more than that of MWCNT.
Keywords: Hybrid Nanofluids; Circular cylinder; SWCNT and
MWCNT; Thermal slip; HPM method
Introduction:
Recent studies reveal that some carbon structures have very good thermal
conductivity. Therefore, diverse studies have been carried out on the
thermal properties of Nano fluids using carbon Nano structres such as
graphite, single-walled carbon nano-tubes (SWCNT), multi-walled carbon
nano-tubes (MWCNT), Nano-diamonds and graphene [1-8]. Carbon
nano-tubes with only one graphene layer are called single-walled carbon
nanotubes, while nanotubes with more than one graphene layer are
described as multi-walled nanotubes that can slip into one another. The
unique characteristics of these materials as a new form of carbon
material include strength, hardness, adhesion, chemical stability,
thermal conductivity and more interesting than all electrical
conductivity, and they have many applications in microelectronics and
Nano electronics, fuel storage, preparing flat panel display,
constructional composite materials, anti-deposition paint,
H2 storage, radar absorber coating, technical tissues,
conductive plastics, improved lifetime batteries, super-capacitors,
super strong fibers, biomass sensors for harmful gases, etc. Iijima
[9] began investigating carbon nanotubes. Experimental research on
MWCNT–H2O nanoliquid stream and heat transfer in the
heat exchanger with cancellous media has been practiced out by Moradi et
al. [10]. Application of retrievable carbon nanotube Nano fluids in
solar desalination system is examined by Chen et al. [11]. In the
similar paper, the influence of surfactants on the resistance and solar
thermal sorption specifications of multi-walled carbon nanotubes Nano
fluids is discussed by Choi et al. [12]. Selimefendigil and Öztop
[13] investigated the MHD free convection of CNT-H2O
nanoliquid in a cavity with a corrugated partition. Also, the use of
carbon nanotube Nano fluid in increasing the efficiency of discharged
tube solar collector studied by Mahbubul et al. [14]. Effect of
magnetic and non-magnetic nanoparticles on mixed convection flow of a
new thermal conductivity model with
Cu-Fe3O4 hybrid nanoliquid over a
straight stretching plate has been done by Hussanan et al. [15]. The
output of this essay indicates that liquids based in SA should be used
to attain high heat transfer rate. Some other essays about carbon
nanotubes nano liquid are in references [16-20].
Hybrid nanofluids are potential fluids that offer better thermal
efficiency and thermos-physical properties than basic heat transfer
fluids (including mineral oils, water and ethylene glycol) and
nanofluids with a single nanoparticle type. Hybrid nanofluid is a new
fluid that is made by dispersing two different types of nanoparticles
into the heat transfer base fluid. Researchers have shown that hybrid
nanofluids can replace conventional coolers, especially fluids that
operate at very high temperatures. Hybrid nanoliquid also has a large
potential to maintain and absorb energy due to the unique and special
structure of any nanoparticle. Another matter propounded in this essay
is the tensile cylinder. Tensile cylinder is increasingly used in the
laboratory to investigate the reaction between liquids and solid
surfaces. This cylinder often works at high temperature gradients.
Recent studies demonstrate the importance of this topic, for example:
Numerical check on entropy generation during natural convection of
hybrid nanoliquid in a sigmoid passage between straight elliptic
cylinders has been done by Tayebi and Öztop [21]. Sundar et al.
[22] discussed friction factor and turbulent heat transfer in a
horizontal tube of Nano diamond-nickel hybrid Nano fluids flow. Impact
of hybrid Nano fluids in solar thermal systems on the proficiency of
parabolic trough gatherers is analyzed by Minea and Maghlany [23].
In the similar paper, Bellos and Tzivanidis [24] considered the mono
and hybrid Nano fluids for thermal investigate of parabolic trough
collector. Entropy generation analysis and heat transfer proficiency in
a flat tube of hybrid Nano fluids is addressed by G. Huminic and A.
Huminic [25]. Some other activities about hybrid Nano fluids and
Nano fluids flow are in references [26-29].
In this research, the aim is to check the characteristics of
3-dimensional flow stagnation point of hybrid nano liquids passing
through circular cylinder with sinusoidal radius. The flow regime is
considered with both electromagnetic source and the effects of thermal
slippage. The potent nonlinear systems calculations are offered using
the analytical manner after non-dimensionalization. Plus, graphical
analysis of the impressive parameters is precisely checked on the
profiles of velocity and temperature for various carbon nano-tubes
(SWCNT - MWCNT).
Mathematical formulation:
The 3-dimensional stream of hybrid nano fluids is considered as
independent of time for a circular cylinder. The cylinder’s radius
changes sinusoidally. It is substantial to note that at each point M, N
and O (utmost and minim radius), there exists an immobility point. The
W, V and U are the component of velocities along Z − path, Y – path and
X – path respectively. Following us have [30]: