Numerical Simulation of Unsteady Natural Convection from Heated Horizontal Circular Cylinders in a Square Enclosure

Abstract

In this article, a 2-D numerical study is carried out to investigate the effect of this interaction on natural convection from two heated horizontal cylinders confined in a square enclosure with isothermal walls at the heat sink temperature. The simulations are carried out for Rayleigh numbers between 103 and 107, and dimensionless horizontal distances of cylinders between 0.1 and 0.4. The results show that the variation of the area-averaged Nusselt number strongly depends on the distance between the two cylinders if Rayleigh numbers are less than 104. In contrary, the effect of cylinder spacing on heat transfer was found to be nearly negligible when the Rayleigh number is between 104 and 107. It is also observed that steady state flow and heat transfer undergo periodical oscillation, and ultimately chaotic oscillation in special positions of cylinders can occur.