Laminar Free Convection of Nanofluid Flow in Horizontal Porous Annulus
A numerical study has been carried out to investigate
the heat transfer by natural convection of nanofluid taking Cu as
nanoparticles and the water as based fluid in a three dimensional
annulus enclosure filled with porous media (silica sand) between two
horizontal concentric cylinders with 12 annular fins of 2.4mm
thickness attached to the inner cylinder under steady state conditions.
The governing equations which used are continuity, momentum and
energy equations under an assumptions used Darcy law and
Boussinesq-s approximation which are transformed to dimensionless
equations. The finite difference approach is used to obtain all the
computational results using the MATLAB-7. The parameters affected
on the system are modified Rayleigh number (10 ≤Ra*≤ 1000), fin
length Hf (3, 7 and 11mm), radius ratio Rr (0.293, 0.365 and 0.435)
and the volume fraction(0 ≤ ¤ò ≤ 0 .35). It was found that the
average Nusselt number depends on (Ra*, Hf, Rr and φ). The results
show that, increasing of fin length decreases the heat transfer rate and
for low values of Ra*, decreasing Rr cause to decrease Nu while for
Ra*
greater than 100, decreasing Rr cause to increase Nu and adding
Cu nanoparticles with 0.35 volume fraction cause 27.9%
enhancement in heat transfer. A correlation for Nu in terms of Ra*,
Hf and φ, has been developed for inner hot cylinder.
[1] D.A. Nield, A. Bejan, Convection in Porous Media, third ed., Springer,
New York, 2006.
[2] D. Ingham, I. Pop, Transport Phenomena in Porous Media, vol. III,
Elsevier, Oxford, 2005.
[3] I. Pop, D.B. Ingham, Convective Heat Transfer: Mathematical and
Computational Modeling of Viscous Fluids and Porous Media,
Pergamon, Oxford, 2001.
[4] Syakila Ahmad, Ioan Pop, Mixed convection boundary layer flow from
a vertical flat plate embedded in a porous medium filled with nanofluids,
International communication in Heat and Mass transfer 37 (2010) 987-
991.
[5] Kaustubh Ghodeswar, Natural Convection in a Porous Medium
Saturated by Nanofluid, M.Sc. thesis, Cleveland State University,
December, 2010.
[6] Dalia Sabina Cimpean, Ioan Pop, Fully developed mixed convection
flow of a nanofluid through an inclined channel filled with a porous
medium, International communication in Heat and Mass transfer 55
(2012) 907-914.
[7] R. Nazar ┬À L. Tham ┬À I. Pop ┬À D. B. Ingham, Mixed Convection Boundary
Layer Flow from a Horizontal Circular Cylinder Embedded in a Porous
Medium Filled with a Nanofluid, Transp Porous Med (2011) 86:517-
536
[8] Mina Shahi, Amir Houshang Mahmoudi, Farhad Talebi, A numerical
investigation of conjugated-natural convection heat transfer
enhancement of a nanofluid in an annular tube driven by inner heat
generating solid cylinder, International communication in Heat and Mass
transfer 38 (2011) 533-542
[9] M. Esmaeilpour, M. Abdollahzadeh, Free convection and entropy
generation of nanofluid inside an enclosure with different patterns of
vertical wavy walls, International Journal of Thermal Science 52
(2012)127-136
[10] Wang Bu - Xuan and Zhang Xing, "Natural Convection in Liquid
Saturated Porous Media Between Concentric Inclined Cylinders" Int. J.
Heat and Mass Transfer Vol. 33. No 5, pp. 827-833, 1990.
[11] Fukuda K., Takata Y., Hasegawa S., Shimomura H. and Sanokawa K.,
"Three - Dimensional Natural Convection in a Porous Medium Between
Concentric Inclined Cylinders", Proc. 19th Natl Heat Transfer Conf.,
Vol. HTD - 8, pp. 97 - 103, 1980
[12] Ram├│n L. F. and Sergio G. M., "Three Dimensional Natural Convection
in Finned Cubical Enclosure", Int. J. of Heat and Fluid Flow, Vol. 28,
pp. 289 - 298, 2007.
[1] D.A. Nield, A. Bejan, Convection in Porous Media, third ed., Springer,
New York, 2006.
[2] D. Ingham, I. Pop, Transport Phenomena in Porous Media, vol. III,
Elsevier, Oxford, 2005.
[3] I. Pop, D.B. Ingham, Convective Heat Transfer: Mathematical and
Computational Modeling of Viscous Fluids and Porous Media,
Pergamon, Oxford, 2001.
[4] Syakila Ahmad, Ioan Pop, Mixed convection boundary layer flow from
a vertical flat plate embedded in a porous medium filled with nanofluids,
International communication in Heat and Mass transfer 37 (2010) 987-
991.
[5] Kaustubh Ghodeswar, Natural Convection in a Porous Medium
Saturated by Nanofluid, M.Sc. thesis, Cleveland State University,
December, 2010.
[6] Dalia Sabina Cimpean, Ioan Pop, Fully developed mixed convection
flow of a nanofluid through an inclined channel filled with a porous
medium, International communication in Heat and Mass transfer 55
(2012) 907-914.
[7] R. Nazar ┬À L. Tham ┬À I. Pop ┬À D. B. Ingham, Mixed Convection Boundary
Layer Flow from a Horizontal Circular Cylinder Embedded in a Porous
Medium Filled with a Nanofluid, Transp Porous Med (2011) 86:517-
536
[8] Mina Shahi, Amir Houshang Mahmoudi, Farhad Talebi, A numerical
investigation of conjugated-natural convection heat transfer
enhancement of a nanofluid in an annular tube driven by inner heat
generating solid cylinder, International communication in Heat and Mass
transfer 38 (2011) 533-542
[9] M. Esmaeilpour, M. Abdollahzadeh, Free convection and entropy
generation of nanofluid inside an enclosure with different patterns of
vertical wavy walls, International Journal of Thermal Science 52
(2012)127-136
[10] Wang Bu - Xuan and Zhang Xing, "Natural Convection in Liquid
Saturated Porous Media Between Concentric Inclined Cylinders" Int. J.
Heat and Mass Transfer Vol. 33. No 5, pp. 827-833, 1990.
[11] Fukuda K., Takata Y., Hasegawa S., Shimomura H. and Sanokawa K.,
"Three - Dimensional Natural Convection in a Porous Medium Between
Concentric Inclined Cylinders", Proc. 19th Natl Heat Transfer Conf.,
Vol. HTD - 8, pp. 97 - 103, 1980
[12] Ram├│n L. F. and Sergio G. M., "Three Dimensional Natural Convection
in Finned Cubical Enclosure", Int. J. of Heat and Fluid Flow, Vol. 28,
pp. 289 - 298, 2007.
@article{"International Journal of Mechanical, Industrial and Aerospace Sciences:53771", author = "Manal H. Saleh", title = "Laminar Free Convection of Nanofluid Flow in Horizontal Porous Annulus", abstract = "A numerical study has been carried out to investigate
the heat transfer by natural convection of nanofluid taking Cu as
nanoparticles and the water as based fluid in a three dimensional
annulus enclosure filled with porous media (silica sand) between two
horizontal concentric cylinders with 12 annular fins of 2.4mm
thickness attached to the inner cylinder under steady state conditions.
The governing equations which used are continuity, momentum and
energy equations under an assumptions used Darcy law and
Boussinesq-s approximation which are transformed to dimensionless
equations. The finite difference approach is used to obtain all the
computational results using the MATLAB-7. The parameters affected
on the system are modified Rayleigh number (10 ≤Ra*≤ 1000), fin
length Hf (3, 7 and 11mm), radius ratio Rr (0.293, 0.365 and 0.435)
and the volume fraction(0 ≤ ¤ò ≤ 0 .35). It was found that the
average Nusselt number depends on (Ra*, Hf, Rr and φ). The results
show that, increasing of fin length decreases the heat transfer rate and
for low values of Ra*, decreasing Rr cause to decrease Nu while for
Ra*
greater than 100, decreasing Rr cause to increase Nu and adding
Cu nanoparticles with 0.35 volume fraction cause 27.9%
enhancement in heat transfer. A correlation for Nu in terms of Ra*,
Hf and φ, has been developed for inner hot cylinder.", keywords = "Annular fins, laminar free convection, nanofluid, porous media, three dimensions horizontal annulus.", volume = "7", number = "6", pages = "1069-7", }