Natural Convection Heat Transfer of a Heated Triangular Rod to its Coaxial Square Enclosure

In this work we investigate the natural convection heat transfer in a two-dimensional horizontal annulus. The study consists of an annular-shape enclosure, which is created between a triangular inner cylinder and a square outer cylinder. The inner and outer surface temperatures were set as hot and cold.The effect of Rayleigh numbers to the enhancement of heat transfer is examined. Furthermore, the effect of vertical and horizontal eccentricities at various locations and rotation of rod is examined. To solve these equations numerically, the finite difference method based on control volume and simple algorithm is used and to solve algebraical equations computational program is written in Fortran. Result shows that the Nusselt number increases by augmentation of Rayleigh number. Also average Nusselt number increases when the inner cylinder moves downward. The results also show that the average Nusselt number was decresed when the triangular rod is reversed.