RT Journal Article
ID 4ae9a1ff75c6088d
A1 Nguyen, Cong Tam
A1 El Ganaoui, Mohammed
A1 Bennacer, Rachid
A1 Mare, Thierry
T1 NATURAL CONVECTION OF NANOFLUIDS IN A CAVITY INCLUDING THE SORET EFFECT
JF Computational Thermal Sciences: An International Journal
JO CTS
YR 2009
FD 2009-07-07
VO 1
IS 4
SP 425
OP 440
AB Convection of a binary mixture in a cavity is studied numerically. The flow is driven by a buoyancy force due to an externally applied constant temperature difference on the vertical wall of the cavity, while the horizontal surfaces are impermeable and adiabatic. A nanofluid is used and the effects of the cross phenomenon "Soret effect" were considered in the analysis. The flows are found to be dependent on the particle concentration φ, the Rayleigh number Ra_{T}, the Lewis number Le, the solutal to thermal buoyancy ratio *N*, and the thermal boundary conditions. Numerical results for finite amplitude convection, obtained by solving numerically the full governing equations, are found to be in good agreement with the analytical solution based on the scale analysis approach. We have proposed a modified formulation of the conservation equations governing the flow and heat transfer of nanofluids, taking into account important changes of nanofluid thermal conductivity and viscosity as well as the spatial change of the particle concentration that is induced by the Soret effect. Results have shown that such an effect increases nanofluid heat transfer. The optimal particle volume concentration, which maximizes heat transfer, is estimated to be 2%. The increase of natural convection with nanoparticle concentration is weak in comparison to that found in forced convection.
PB Begell House
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