The Effect of Increasing the Thickness of an Annular Space Subjected to a Heat Flux Emitted by a Solar Panel on the Dynamic and Thermal Fields

The present work is a 3D numerical simulation, in an annular space between two horizontal concentric cylinders in which an incompressible fluid circulates. The wall of the inner cylinder is adiabatic while the wall of the outer cylinder is subjected to a constant thermal heat flux. The model equations of continuity, momenta and energy are numerically solved by the finite volume method with a second order spatiotemporal discretization. The used mesh is 52 × 44 × 162 nodes along the radial, angular and axial directions. The studied hydraulic diameters are: Dh = 0.75, 1.0, and 1.25 cm. The purpose of this work is to improve the heat transfer by increasing the thickness of the annular space, this allowed us to study the dynamic and thermal fields of the heat transfer fluid and make a comparison of average temperatures and Nusselt numbers for three different cases. The results obtained show that despite the qualitative similarity of thermal and dynamic fields for the three studied cases, the heat transfer increases when the thickness of the annular space is increased, this is justified by the increase in the Nusselt number.