Heat and fluid flow in an uneven heated chimney

A 2D numerical study of the natural convection flow in an asymmetrically heated vertical plane channel is carried out in the boundary layer regime for three modified Rayleigh numbers (Ra*) between 2.25·106 and 9·106. This configuration is seen to be a simplified model of an electrical heater. This study focuses on the influence of different spatial arrangements of the heat sources on both heat transfer and flow dynamics, and especially on the back flow. In order to simplify the analysis, the working fluid is water, making thermal radiation negligible. It is shown that, at constant heat power and exchange surface, two distant heat sources are more efficient to put fluid into motion and to transfer heat.