ABSTRACT
In this paper, a new approach is used for numerical analysis of the sole effects of nanoparticles volume fraction of Cu-water nanofluid on laminar mixed and natural convection heat transfer in a 2D cavity. Horizontal walls are insulated and fixed, and vertical walls are maintained at constant temperature. Vertical walls are considered for both fixed and moving conditions. Some researchers have studied flow and heat transfer of nanofluid in a lid-driven cavity, keeping fixed both Ri and Gr. They found that by the increase of nanoparticles volume fraction, Nu number increases, then from this result they concluded the total heat transfer increases from the walls. It is shown that total heat transfer obtained from the Nu number by the mentioned approach results from not only the nanoparticles volume fraction increase but also temperature difference and walls velocity increases. Thus, this approach is not appropriate to study the sole effects of nanoparticles volume fractions on the mixed convection heat transfer. Using the new approach, it is shown that in order to have specific heat transfer rate from the walls, base fluid (water) needs less power for moving the wall than cu-nanofluid. Therefore, the usage of Cu-water nanofluid is not recommended to increase mixed convection heat transfer in a lid-driven cavity. Moreover, using this new approach, it is shown that the increase of nanoparticles volume fraction reduces natural convection heat transfer, which is contradictory to the previous studies. Thus, its usage is not recommended for this case as well.
KEYWORDS
PAPER SUBMITTED: 2013-03-01
PAPER REVISED: 2013-09-14
PAPER ACCEPTED: 2013-09-14
PUBLISHED ONLINE: 2013-11-16
THERMAL SCIENCE YEAR
2016, VOLUME
20, ISSUE
Issue 2, PAGES [405 - 414]
- Khanafer K., Vafai. K., Lightstone. M., Buoyancy-driven heat transfer enhancement in a two-dimensional enclosure utilizing nanofluids, Int J heat mass tran, 46, (2003), pp. 3639-3653.
- Oztop H.F., Abu-Nada. E., Numerical study of natural convection in partially heated rectangular enclosures filled with nanofluids, Int J heat fluid fl, 29, (2008), pp. 1326-1336.
- Rong-Yuan Jou a, Sheng-Chung Tzeng, Numerical research of natural convective heat transfer enhancement filled with nanofluids in rectangular enclosures, Int commun heat mass, 33, (2006), pp. 727-736.
- Refai Ahmed. G., and M. M. Yovanovich, Numerical Study of Natural Convection from Discrete Heat Sources in a Vertical Square Enclosure, J. thermophysics, 6, (1992).
- Chen. C.J. Ho, M.W, Z.W. Li, Numerical simulation of natural convection of nanofluid in a square enclosure: Effects due to uncertainties of viscosity and thermal conductivity, Int J heat mass tran, 51, (2008), pp. 4506-4516.
- Sik Hwang. K, Ji-Hwan Lee, Seok Pil Jang, Buoyancy-driven heat transfer of water-based Al2O3 nanofluids in a rectangular cavity, Int J heat mass tran, 50, (2007), pp. 4003- 4010.
- Zi-Tao Yu, Xu Xu, Ya-Cai Hu, Li-Wu Fan, Ke-Fa Cen, Numerical study of transient buoyancy-driven convective heat transfer of water-based nanofluids in a bottom-heated isosceles triangular enclosure, Int J heat mass tran, 54, (2011), pp. 526-532.
- Rong-Yuan Jou a, Sheng-Chung Tzeng, Numerical research of nature convective heat transfer enhancement filled with nanofluids in rectangular enclosures, Int commun heat mass, 33, (2006), pp. 727-736.
- Cianfrini, M., Corcione, M., Quintino, A., Natural convection in square enclosures differentially heated at sides using alumina-water nanofluids with temperature-dependent physical properties, j therm sci, (2012).
- Ching-Chang Cho., Her-Terng Yau., Cha'o-Kuang Chen., Enhancement of natural convection heat transfer in a u-shaped cavity filled with AL2O3-water nanofluid, j therm sci, 16, (2012), 5, pp. 1317-1323.
- Akbarinia, A., Behzadmehr, A., Numerical study of laminar mixed convection of a nanofluid in horizontal curved tubes, Appl therm eng, 27, (2007), pp. 1327-1337.
- Hakan, F., Oztop, a., Ihsan Dagtekin b, Mixed convection in two-sided lid-driven differentially heated square cavity, Int J heat mass tran, 47, (2004), pp. 1761-1769.
- Chin-Lung Chen, Yun-Chi Chung, Te-Fu Lee, Experimental and numerical studies on periodic convection flow and heat transfer in 2 a lid-driven arc-shape cavity, Int J heat mass tran, (2012).
- Sharif, M.A.R., Laminar mixed convection in shallow inclined driven cavities with hot moving lid on top and cooled from bottom, Appl therm eng, 27, (2007), pp. 1036-1042.
- Tiwari, R., Kumar Das, M., Heat transfer augmentation in a two-sided lid-driven differentially heated square cavity utilizing nanofluids, Int J heat mass tran, 50, (2007), pp. 2002-2018.
- Talebi, F., Mahmoudi A.H., Shahi M., Numerical study of mixed convection flows in a square lid-driven cavity utilizing nanofluid, Int commun heat mass, 37, (2010), pp. 79-90.
- Muthtamilselvan, M., Kandaswamy P., Lee J., Heat transfer enhancement of copper-water nanofluids in a lid-driven enclosure, Commun Nonlinear SciNumerSimulat 15, (2010), pp. 1501-1510.
- Mahmoodi, M., Mixed convection inside nanofluid filled rectangular enclosures with moving bottom wall, j therm sci, 15, (2011), 3, pp. 889-903.
- Pourmahmoud, N,. Ghfouri, A., Mirzaee, I., Numerical study of mixed convection heat transfer in lid-driven cavity utilizing nanofluid: effect of type and model of nanofluid, j therm sci, (2013).
- Xuan, Y., Li Q., Investigation on convective heat transfer and flow features of nanofluids, ASME Int J heat mass tran, 125, (2003), pp. 151-155.
- Brinkman H.C., The viscosity of concentrated suspensions and solutions, J. Chem. Phys. 20, (1952), pp. 571-581.
- Maxwell, J., A Treatise on Electricity and Magnetism, 2nd ed., Oxford University Press, Cambridge, UK, 1904.