TY - JOUR
TI - Numerical study of natural turbulent convection of nanofluids in a tall cavity heated from below
AU - Mebrouk Ridha
AU - Kadja Mahfoud
AU - Lachi Mohamed
AU - Fohanno Stéphane
JN - Thermal Science
PY - 2016
VL - 20
IS - 6
SP - 2051
EP - 2064
PT - Article
AB - In the present paper a numerical study of natural turbulent convection in a  tall cavity filled with nanofluids. The cavity has a heat source embedded on  its bottom wall, while the left, right and top walls of the cavity are  maintained at a relatively low temperature. The working fluid is a water  based nanofluid having three nanoparticle types: alumina, copper and copper  oxid. The influence of pertinent parameters such as Rayleigh number, the type  of nanofluid and solid volume fraction of nanoparticles on the cooling  performance is studied. Steady forms of twodimensional  Reynolds-Averaged-Navier-Stokes equations and conservation equations of mass  and energy, coupled with the Boussinesq approximation, are solved by the  control volume based discretisation method employing the SIMPLE algorithm for  pressure-velocity coupling. Turbulence is modeled using the standard k-ε  model. The Rayleigh number, Ra, is varied from 2.491009 to 2.491011. The  volume fractions of nanoparticles were varied in the interval 0≤φ≤ 6% .  Stream lines, isotherms, velocity profiles and Temperature profiles are  presented for various combinations of Ra, the type of nanofluid and solid  volume fraction of nanoparticles. The results are reported in the form of  average Nusselt number on the heated wall. It is shown that for all values of  Ra, the average heat transfer rate from the heat source increases almost  linearly and monotonically as the solid volume fraction increases. Finally  the average heat transfer rate takes on values that decrease according to the  ordering Cu, CuO and Al2O3.