Open AccessNumerical analysis of natural convection in a prismatic enclosure
Author(s) -
Walid Aich,
Imen Hajri,
Ahmed Omri
Publication year - 2011
Publication title -
thermal science/thermal science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.339
H-Index - 43
eISSN - 2334-7163
pISSN - 0354-9836
DOI - 10.2298/tsci1102437a
Subject(s) - natural convection , rayleigh number , aspect ratio (aeronautics) , mechanics , enclosure , heat transfer , isosceles triangle , materials science , pitchfork bifurcation , rayleigh scattering , vortex , heat flux , thermodynamics , isothermal process , fluid dynamics , bifurcation , physics , hopf bifurcation , geometry , mathematics , optics , composite material , nonlinear system , telecommunications , quantum mechanics , computer science
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.