Fluid flow and heat transfer maximization of elliptic cross- section tubes exposed to forced convection: A numerical approach motivated by Bejan's theory

摘要

This work investigates, through Constructal Design, the impact of the spacing between two cylindrical bodies with elliptic cross-section in the maximization of the heat transfer density under external forced convection flow. The horizontal-to-vertical axis ratio of the cross-section is also analyzed. The model is assumed two-dimensional, steady, incompressible, and laminar. The flow arises due to a pressure difference, which is expressed in terms of Bejan number. In addition, for all cases, thermophysical properties are defined by constant Prandtl number (Pr = 0.72). The conservation equations of momentum, energy, and mass are solved numerically by means of the Finite Volume Method. Results show that the optimal configurations perform considerably better, increasing the heat transfer density between 50% and 97% when compared to the lower level cases investigated. Additionally, it has been demonstrated that the system tends to adapt its optimal architecture to every flow studied and provides a favorable flow configuration that achieves the objective function, i.e. maximizes the heat transfer in a reduced physical domain: this is fully consistent with the principles of Constructal Law.