TY - JOUR
TI - Numerical analysis of natural convection in a prismatic enclosure
AU - Aich Walid
AU - Hajri Imen
AU - Omri Ahmed
JN - Thermal Science
PY - 2011
VL - 15
IS - 2
SP - 437
EP - 446
PT - Article
AB - Natural convection heat transfer and fluid flow have been examined  numerically using the control-volume finite-element method in an isosceles  prismatic cavity, submitted to a uniform heat flux from below when inclined  sides are maintained isothermal and vertical walls are assumed to be perfect  thermal insulators, without symmetry assumptions for the flow structure. The  aim of the study is to examine a pitchfork bifurcation occurrence. Governing  parameters on heat transfer and flow fields are the Rayleigh number and the  aspect ratio of the enclosure. It has been found that the heated wall is not  isothermal and the flow structure is sensitive to the aspect ratio. It is  also found that heat transfer increases with increasing of Rayleigh number  and decreases with increasing aspect ratio. The effects of aspect ratio  become significant especially for higher values of Rayleigh number.  Eventually the obtained results show that a pitchfork bifurcation occurs at a  critical Rayleigh number, above which the symmetric solutions becomes  unstable and asymmetric solutions are instead obtained.