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FINITE VOLUME ANALYSIS OF CONVECTIVE HEAT TRANSFER AUGMENTATION FROM
HORIZONTAL RECTANGULAR FIN BY ELLIPTICAL PERFORATIONS
R.B.Gurav
J.D.Patil
Assistant Professor
Army Insitute of Technology Pune,
Maharashtra, India
Assistant Professor
Army Insitute of Technology Pune,
Maharashtra, India
S.M.Gaikwad
Pritee Purohit
A.A.Ramgude
Assistant Professor
Army Insitute of Technology
Pune,
Maharashtra, India
Assistant Professor
Army Insitute of Technology
Pune,
Maharashtra, India
Assistant Professor
Army Insitute of Technology
Pune,
Maharashtra, India
Abstract:
This study examines heat transfer augmentation from a horizontal rectangular fin embedded with elliptical
perforation under natural convection compared to the equivalent solid (none perforated) fin using finite volume
method. The parameters considered were geometrical dimensions and thermal properties of the fin and that of the
perforations. This study shows that the heat dissipation from the perforated fin results in improved heat transfer
over the equivalent solid fin. The heat transfer augmentation of perforated fin increases as fin thermal conductivity
increases.
Key Word: FVA,Fin, elliptical Perforations.
I Introduction:
The extended surfaces(fins) are frequently used in
heat exchanging devices for the purpose of
increasing the heat transfer between a primary
surface and the surrounding fluid.
E.A.M.Elshafei[1] performed the experiment on
natural convection heat transfer from circular pin
fin heat sinks subject to the influence of its
geometry, heat flux and orientation. The geometric
dependence of heat dissipation from heat sinks of
widely spaced solid and hollow/perforated circular
pin fins with staggered combination, fitted into a
heated base of fixed area is discussed. They
concluded that the heat transfer performance for
heat sinks with hollow/perforated pin fins was
better than that of solid fins. Wadah Hussein Abdul
Razzaq Al-Doori[2] An experimental study was
conducted to investigate the enhancement of natural
convection heat transfer from the rectangular fins
by circular perforations. They showed that the heat
transfer rate and the coefficient of heat transfer
increases with increased number of perforations.
Abdullah H. AlEssa, Ayman M.Maqableh and
Shatha Ammourah[3] they showed that ,for a
certain range of rectangular dimension and space
between perforations ,there is an augmentation in
heat dissipation and a reduction in weight over that
of the equivalent solid one. Also the heat transfer
enhancement of the perforated fin increases as the
fin thickness and thermal conductivity increase.
M.R.Shaeri, M.Yaghoubi, K.Jafarpur[4] Fluid flow
and conjugate conduction-convective heat transfer
from a three-dimensional array of rectangular
perforated fins with square windows that are
arranged in lateral surface of fins are studied
numerically.Results show that perforated fins have
higher total heat transfer and considerable weight
reduction in comparison with solid fins. Bayram
Sahin, Alparslan Demir[5] paper reports on heat
transfer enhancement and the corresponding
pressure drop over a flat surface equipped with
square cross-sectional perforated pin fins in a
rectangular channel. Abdullah H. AlEssa[6] Heat
transfer dissipation from a horizontal rectangular fin
embedded with equilateral triangular perforations is
compared numerically using one-dimensional finite
element technique.The heat dissipation of the
perforated fin is computed and compared with that
of the solid one of the same dimensions and same
thermal properties. The comparison refers to
acceptable results and heat dissipation enhancement
due
to
certain
perforations.
M.R.Shaeri,
M.Yaghoubi[7] Three dimensional incompressible
laminar fluid flow and heat transfer of a heated
array of rectangular perforated and solid fins
attached on a flat surface are studied numerically.
Thermal performances and effectiveness as well as
friction coefficient of perforated and solid fins are
determined
and
compared.
A.T.Pise,
U.V.Awasarmol[8]Experimental
studies
were
conducted to analyze the natural convection heat
transfer using solid & perforated fins for engine
cylinder.
II Physical Geometry and meshing
A Physical Geometry of simple fin
B Physical Geometry of fin with elliptical perforation
C Meshing of simple fin
D Meshing of fin with elliptical perforation
Figure1 Physical geometry and meshing of simple fin and fin with elliptical protrusion
III Computational methodology
The governing equations are the continuity,
momentum, and energy equations. The flow is
studied under the following assumptions: steadystate, constant fluid properties and no natural
convection and body forces. The governing
equations for steady mixed convection flow using
conservation of mass, momentum and energy can
be written as,
(1)
(2)
locations. The convergence criterion is that the
residual variations of the mass, momentum and
energy conservation equations become less than
10-5.The numerical model is validated by solving
the velocity and temperature fields in dimple
plate with smooth surfaces, constant inlet velocity
and equal wall temperatures.
A. Boundary Condition at Inlet
Velocity of air
=0.001 m/s
Static air Temperature =20oC
Pressure
=105 Pa
(3)
B At all walls
(4)
Since the Velocity Component, u and v both are
zero at the walls for no-slip conditions, the walls
are considered as adiabatic.
The computational package, ANSYS Fluent, has
been used for the numerical model. It is a 3D solver
of the Reynolds Averaged Navier Stokes equations
based on the finite volume formulation. Triagonal
cells are used to discretize the problem domain
with a structured mesh. Grid points are
distributed in a non-uniform manner with a
higher concentration near the walls due to
higher variable gradients expected in these
C. At the plate surface
Since the velocity component, u and v both are
zero at the walls for no-slip conditions. The object
is assumed to be isothermally heated.
D. Boundary Condition at outlet is Opening (Open
to atmosphere), Relative pressure
=0 Pa
IV Result
E Temperature Profile of simple fin along x-y plane
F Temperature Profile of fin with elliptical
perforation along x-y plane(M6)
G Temperature Profile of simple fin along x-z plane
H Temperature Profile of fin with elliptical
perforation along x-z plane
J Pressure Profile of fin with elliptical perforation
along x-y plane
Figure2 Comparison of simple fin and fin with elliptical perforation
I Pressure Profile of simple fin along x-y plane
From figure 2 E to J it is observed that fins with
elliptical perforation gives better heat transfer and
flow distribution.
rectangular perforations with aspect ratio of
two” International Journal of physical sciences,
vol.4(10),pp.540-547,2009
V Conclusion
[4]M.R.Shaeri, M.Yaghoubi, K.Jafarpur, “Heat
transfer analysis of lateral perforated fin heat
sinks” Energy 86,pp.2019-2029, 2009
Figure 2 E to J show that fins with elliptical
perforation gives better heat transfer and flow
distribution. So it is recommended that the fin with
elliptical perforation gives better result than the
simple fin. The perforation on the fin increase heat
transfer effect and decreases the expenditure of
the fin material.
REFERENCES
[1] E.A.M.Elshafei, “ Natural Convection heat
transfer from a heat sink with hollow/perforated
circular pin fins” Energy,35:2870-2877.
[2] Wadah Hussein Abdul Razzaq Al-Doori, “
Enhancement of natural convection heat
transfer from the rectangular fins by circular
perforations”
International
journal of
Automotive and Mechanical Engineering
,vol.4,pp.428-436,2011
[3] Abdullah H. AlEssa, Ayman M.Maqableh
and Shatha Ammourah, “Enhancement of
natural convection heat transfer from a fin by
[5] Bayram Sahin, Alparslan Demir,
“Performance analysis of a heat exchanger
having perforated square fins” Applied Thermal
Engineering 28 ,pp.621-632,2008
[6] Abdullah H. AlEssa, “One dimensional
finite element heat transfer solution of a fin
with triangular perforations of bases parallel
and towards its base” Appl. Mech. 79,pp.741751,2009
[7] M.R.Shaeri, M.Yaghoubi, “ Thermal
enhancement from heat sinks by using
perforated fins” Energy conversion and
management 50,pp.1264-1270,2009
[8]A.T.Pise, U.V.Awasarmol, “ Investigation of
enhancement of natural convection heat transfer
from engine cylinder with permeable fins”
International
journal of
Mechanical
Engineering and Technology,pp.238-247,2010