Proposal of two kinds of composite heat-dissipation structures composed of high-conductivity-channels and T-shaped fins and their constructal designs

Two composite heat-dissipation structure models, fan-shaped and clover-shaped high-conductivity-channels externally connected to T-shaped fins within square shaped heat-generating-body, are established in this paper. Constructal designs are performed aiming at minimizing entropy-generation-rate and maximum-temperature-difference, with the release of multiple degree-of-freedoms, from one-degree-of-freedom to four-degree-of-freedoms. The results indicate that four degree-of-freedoms design remarkably outperforms the one degree-of-freedom design. Specifically, for the composite-structure with fan-shaped high-conductivity-channel, minimum maximum-temperature-difference is reduced by 10.6%, if thermal-conductivity-ratio grows from 100 to 600. For the composite-structure with clover-shaped high-conductivity-channel, minimum entropy-generation-rate shows a 13.5% reduction, under the same thermal conductivity variation. Regarding the thermal-conductivity-ratio, when it exceeds 500, further increases lead to negligible performance improvements. Thermal-conductivity-ratio of 500 can serve as a cost-effective reference point to balance material costs and heat-dissipation efficiency. Slender channel and fin geometries enhance heat-dissipation by optimizing heat conduction paths and expanding convective heat exchange areas. The composite-structure with clover-shaped high-conductivity-channel demonstrates superior performance, achieving 22.97% lower maximum-temperature-difference and 1.38% lower entropy-generation-rate than composite-structure with fan-shaped high-conductivity-channel under the same conditions. The important contributions herein are proposal of two kinds of composite heat-dissipation structures and realization of constructal designs for them with two different performance indicators, minimizing entropy-generation-rate and minimizing maximum-temperature-difference.