ABSTRACT
Two-dimensional steady laminar natural convection in a differentially heated cavity
filled with water and has various aspect ratios due to buoyancy force effect is
analyzed numerically. The governing mass, momentum and energy equations are
considered and a finite volume algorithm is used to capture the numerical solution.
The left vertical side wall of the cavity is linearly heated while the right vertical one is
maintained at constant cold temperature. The bottom wall is maintained at constant
hot temperature while the top wall is considered thermally insulated. The Rayleigh
number is varied from 103 to 106, while the cavity aspect ratio (W/H) is varied as 0.5,
1.0 and 2.0 respectively. Results are presented in the form of streamline and
isotherm contours. The results of the present work explain that the natural
convection phenomenon is significantly influenced by changing the cavity aspect
ratio, so that when the aspect ratio is high the convection effect is week and vice
versa. Also, it is found that non-uniform heating in the left vertical sidewall of the
cavity plays a major role to improve the heat transfer rates. For uniform and nonuniform
heating of the bottom wall and left vertical sidewall respectively, the local
Nusselt number at these walls increases from its minimum value at the left edge of
these walls toward maximum value at the right edge. While, the average Nusselt
number for both left side and bottom walls increases with increasing of Rayleigh
number.