Effects of aspect ratio on natural convection heat transfer in a parallelogrammic enclosure heated from below

Abstract EN

In this study, a finite volume method based on computational procedure is used to investigate natural convection in a parallelogrammic enclosure heated from below.

The physical system used for flow and heat transfer analysis has been bounded by adiabatic top wall, constant temperature cold side walls and hot bottom wall.

The bottom wall is subjected to uniform temperature and flow within the enclosure at steady state, two-dimensional, and laminar.

The Cartesian velocity components and pressure on a collocated grid are used as dependent variables in the momentum equations, which discretized by finite volume method; body fitted coordinates are used to represent the parallelogrammic enclosure, and grid generation technique based on elliptic partial differential equations is employed.

Simple algorithm is used to adjust the velocity field to satisfy the conservation of mass.

Parametric study for a wide range of Rayleigh number (, the inclination angles of the side walls ( ), the aspect ratios range ( ⁄ ) ( (, and Prandtl number is ( ) shows consistent performance of the present numerical approach to obtain the solutions as stream functions and temperature profiles.

Heat transfer rates at the heated wall are presented in terms of average Nusselt number ( ).

The results show that the average Nusselt number ( ) increases as aspect ratio ( ) and Rayleigh number ( ) increase.

Also, it is observed that the "effect" of aspect ratio of the enclosure is one of the most important parameter on flow and heat transfer.

Increasing the leads to increase the flow strength and heat transfer rate.