TY - JOUR
TI - Rayeilgh number effect on the turbulent heat transfer within a parallelepiped cavity
AU - Aksouh Mohamed
AU - Mataoui Amina
AU - Seghouani Nassim
AU - Haddad Zoubida
JN - Thermal Science
PY - 2011
VL - 15
IS - 12
SP - 341
EP - 356
PT - Article
AB - This purpose is about a three dimensional study of natural convection within  cavities. This problem is receiving more and more research interest due to  its practical applications in the engineering and the astrophysical research  The turbulent natural convection of air in an enclosed tall cavity with high  aspect ratio (AR=H/W=28.6) is examined numerically. Two cases of differential  temperature have been considered between the lateral cavity plates  corresponding, respectively, to the low and high Rayleigh numbers: Ra=8.6×105  and Ra=1.43×106 [1]. For these two cases, the flow is characterized by a  turbulent low Reynolds number. This led us to improve the flow  characteristics using two one point closure low-Reynolds number turbulence  models: RNG k-e model and SST k-w model, derived from standard k-e model and  standard k-w model, respectively. Both turbulence models have provided an  excellent agreement with the experimental data. In order to choose the best  model, the average Nusselt number is compared to the experiment and other  numerical results. The vorticity components surfaces confirm that the flow  can be considered two-dimensional with stretched vortex in the cavity core.  Finally, a correlation between Nusselt number and Rayleigh number is obtained  to predict the heat transfer characteristics.