Adding branched fin angle as degree-of-freedom improves performance of a T-Y-shaped fin

A variable-angle T-Y-shaped fin model is built herein. Constructal design of the variable-angle T-Y-shaped fin model is studied by introducing branched fin angle as an additional design variable. Firstly, with the goal of minimizing maximum dimensionless excess temperature (MDET), the branched fin angle of T-Y-shaped fin model is optimized. Secondly, heat transfer performance of T-Y-shaped fin is further optimized with 2-degree-of-freedom (DOF) and 3-DOF optimizations including branched fin angle. According to the results, in the 1-DOF optimization, when the branched fin angle reaches 17.2°, the MDET reaches the minimum at the value of 30.78, which is 19.32 % lower than that when the branched fin angle is 90°. Furthermore, the MDET of the T-Y-shaped fin under 3-DOF optimization is 27.20, which is 28.70 % lower than the result when the branched fin angle is 90°, and 11.63 % lower than that of the 1-DOF optimization. It is necessary to add the branched fin angle as an optimization variable. Moreover, the optimization effect of 2-DOF is significant, while that of 3-DOF is not obvious. The outcomes obtained from this study may serve as theoretical counsels for heat dissipation in the designs of fins for various thermal systems.