Laminar natural convection in square enclosure containing different cross sections of inner pipes with internal heat generation

Abstract EN

This paper investigated numerically laminar natural convection inside a square enclosure containing different cross section inner pipes (circular, square and triangular) which have the same peripheral area with internal heat generation.

The numerical investigated were carried out by solving the governing equations (Continuity, Momentum and Energy Equations) using Tri-Diagonal Matrix Algorithm (TDMA) by means of the finite- elements method.

The external walls of the square enclosure are kept at hot temperature (Th) while the walls of inner pipes are kept at lower temperature (Tc).

Flow and heat transfer characteristics through isotherms, streamlines and local Nusselt number have been presented and discussed for external Rayleigh number equal to (106), while internal Rayleigh number is varied from (105) to (108).

The working fluid is air with Prandtle number (Pr = 0.71).

Computational results show that the heat transfer mechanism, the stream line and formation of vortices are dependent on the values of internal Rayleigh number.

The effect of different cross section inner pipes on the temperature distribution and stream lines was discussed.