Evolutionary design investigation applied to mixed convection heat transfer flows over semi-elliptical blocks inserted into a rectangular channel

This numerical manuscript focuses on the constructal design of a system characterised by mixed convection heat transfer flows over the heated semi-elliptical devices installed into a horizontally oriented channel. The primary aim of this study is to increase the heat transfer rate and decrease the pressure drop in the system by changing the two blocks’ geometry. The constraints, degrees of freedom, and performance metrics are chosen according to the constructal design method. The technique for order preference by similarity to the ideal solution method evaluates the multi-objective problem. By comparing the best and worst shapes, an increase of 40% for the thermal and 703% for fluid dynamic performances is noticed in the second optimisation level. Also noteworthy is the importance of evaluating different arrangements of the blocks within the channel, and the difference in performance obtained is up to 40% for the thermal and 12% for the fluid dynamic cases, respectively. In the multi-objective viewpoint, the above-cited method allowed the achievement of recommendations for designing the intruded fins, considering several scenarios where the fluid dynamic and thermal purposes are more or less dominant.