Abstract
This study investigates the performance of a micro heat sink featuring a biomimetic structure (inspired by the optimized flow pattern around fish pectoral fins) utilizing an eco-friendly modified graphene oxide-based nanofluid (W-rGO/H2O). The geometrical model was designed using CATIA-V5 software, and a 3D-dimensional simulation was conducted via the finite volume method in ANSYS Fluent software under incompressible, viscous, and laminar flow conditions. The results indicate that in the modified design, increasing the Reynolds number from 500 to 1500 leads to a 31.8% reduction in the maximum surface temperature. Furthermore, varying the nanoparticle concentration from 1% to 3% in this geometry results in a 4.69% decrease in the central processing unit (CPU) operating temperature. An examination of the heat transfer coefficient reveals that at a Reynolds number of 1000, the biomimetic geometry provides a 10% to 17% enhancement in thermal performance compared to the baseline design. Concurrently, the temperature uniformity analysis shows a 9.61% reduction in this index for the optimized design. From a hydraulic perspective, increasing the nanoparticle concentration from 1% to 3% at a Reynolds number of 1000 causes a 32.36% increase in the pressure drop. Exergy analysis of the system demonstrated that under optimal conditions, the outlet exergy ranges from 4.40 to 10.07 W, and the exergy loss ranges from 129.5 to 138.3 W. The maximum second-law efficiency under these conditions was calculated to be 7.16%, indicating the system's satisfactory performance from a thermodynamic standpoint. These findings represent a significant step toward developing sustainable cooling systems for advanced electronic applications.