TY  - EJOU
AU  - Oyewola, Olanrewaju M. 
AU  - Afolabi, Samuel I. 

TI  - NUMERICAL SIMULATION OF NATURAL CONVECTION IN  RECTANGULAR CAVITIES WITH DIFFERENT ASPECT RATIOS
T2  - Frontiers in Heat and Mass Transfer

PY  - 2021
VL  - 17
IS  - 1
SN  - 2151-8629

AB  - The problem of natural convection in rectangular cavities with different aspect ratios has been numerically analyzed in this study. Cavities considered 
have their right vertical walls heated and cooled at the opposite with constant temperatures, while horizontal walls are kept adiabatic. The objective of 
this study is to ascertain the significant effects of Rayleigh numbers (Ra), Nusselt numbers (Nu) and aspect ratios (AR) on flow and heat transfer in 
rectangular cavities. The equations of Navier-Stokes and energy are solved by applying Galerkin weighted residual Finite Element Method. Parametric 
calculations are performed for Rayleigh numbers (Ra) ranging from 104
to 108
and for aspect ratios (AR=0.25, 0.5, 1 and 2). Variations of Streamlines 
and Isotherms contours of the resulting flow fields and temperatures are presented in correlation with the estimated Nusselt numbers (Nu) for a fluid 
measured at air room temperature having Prandtl number (Pr) of 0.71. The results of the numerical simulation reveals that at higher Rayleigh number 
of flow, heat transfer in rectangular cavities increases. The Nusselt number estimated close to the boundary of the hot wall indicate a predominant heat 
transfer by convection in higher AR, hence, results indicates that with increasing aspect ratio, the thermal boundary layer thickness were steadily 
increased thereby contributing to major heat transfer of fluid by convection in the rectangular cavities. The engineering application of natural convection 
in cavities such as thermal storage facilities has made this study significant.
KW  - <i>Cavity
KW  -  fluid flow
KW  -  Galerkin finite element
KW  -  heat transfer
KW  -  natural convection.</i>

DO  - 10.5098/hmt.17.11