EXPERIMENTAL AND NUMERICAL STUDY OF NATURAL CONVECTION BETWEEN TILTED WALLS WITH ATTACHED FINS

Abstract

The free convection between two tilted adiabatic plates with centered heated horizontalcylinder with attached plate fin was investigated experimentally and numerically. Theexperimental rig constructed from vertical adiabatic was filled with air plates with aspectratio of (A= 12) tilted by angles of (15o, 30o, 45o, 60o, 75o, and 90o). A horizontal heatedcylinder with diameter of (16 cm) subjected under constant heat flux of (100, 500, 700, and1000 W/m2), the Rayleigh number ranging from (3.5 ×107 to 4.5 ×109). At the bottom of therig left an opining with distance of (2, 4, 6, and 8 cm) but the upper left open to theatmosphere. The tested cases was of (without fin, smooth, triangular, square, and semi-circlefin) was attached to the right wall of the cavity. The numerical solution of the case wasperformed by solving the governing equations by ANSYS-FLUENT 14.0 package thatdependent upon the finite volume method. The experimental results show that the Nusseltnumber increases with increasing Rayleigh number, decreasing the inclination angle,increasing heat flux and with increasing the bottom opining distance. Basically, the resultsshowed that the using fins with any geometry will lead to increase the heat transfer rate. Theoptimum increasing in the Nusselt number was found by using triangular plat fin. Finally,the experimental data was compared with a numerical calculation and found that there is agood agreement in the same conditions.