Buoyancy-Induced Convection in Water From a Pair of Horizontal Heated Cylinders Enclosed in a Square Cooled Cavity

Buoyancy-driven convention from a pair of horizontal heated cylinders, set side by side inside a square cooled cavity filled with water, is studied numerically. The system of the conservation equations of mass, momentum and energy expressed in dimensionless form is solved through a control-volume formulation of the finite-difference method. The pressure-velocity coupling is handled using the SIMPLE-C algorithm. Numerical simulations are executed for different values of the Rayleigh number based on the cylinder diameter, as well as the width of the cavity, the inter-cylinder spacing and the distance of the cylinders from the bottom wall of the cavity normalized by the cylinder diameter. Two heat and fluid flow configurations are generally found to establish inside the cavity, according as the cylinders are located at close distance or at such a distance that the effects of the lateral walls of the cavity become important, each of these configurations being distinguished by the existence of an optimum inter-cylinder spacing which maximizes the overall heat transfer rate. Moreover, when the inter-cylinder spacing is such that the cylinders are located sufficiently close to the cavity sides, a periodic flow arises.