Abstract
Effective thermal management is essential for maintaining reliability and performance of modern electronic devices as heat generation increases with system miniaturisation. This study presents a numerical investigation of fluid flow and heat transfer in wavy microchannel heat sinks with circular pin inserts of varying heights ranging from 0 to 0.4 mm. A 3D conjugate heat transfer model was developed in ANSYS Fluent to evaluate thermal-hydraulic performance with Reynolds numbers ranging from 300 to 800. The microchannels were examined with wave amplitudes of 0, 150, and 250 μm. Water was used as the coolant and a constant heat flux of 50 W/cm2 was applied at the base of the heat sink. Key performance indicators including the Nusselt number, friction factor, and performance evaluation criterion were used to assess heat transfer enhancement and flow resistance. Results show that channel waviness significantly improves heat transfer, with the 250 μm amplitude channel outperforming the straight and 150 μm channels. Increasing pin height further enhances the Nusselt number, reaching about 15% higher than the smooth channel, although it also increases the pressure drop. The best overall thermalhydraulic performance was obtained for a wavy microchannel with 250 μm amplitude and a pin height of 0.1 mm.