Numerical Investigation of Wavy Microchannel Heat Sinks with Dual-Outlet Architectures Using Fe3O4 Nanofluids

Abstract

: The thermo-hydraulic performance of three wavy microchannel heat-sink architectures, namely single-inlet single-outlet (SISO), single-inlet dual-outlet (SIDO), and branched single-inlet dual-outlet (BSIDO) configurations, are numerically investigated using deionized water and low-concentration Fe 3 O 4 nanofluids for electronic thermal management. Steady-state laminar flow and heat transfer simulations are performed over Reynolds numbers of 700–1300 for Fe 3 O 4 nanoparticle concentrations of 0.1%, 0.3%, and 0.5%, within a consistent numerical framework and under prescribed wall thermal boundary conditions. The Nusselt number, friction factor, and Performance Evaluation Criterion ( PEC ) are employed to assess the coupled thermal and hydraulic performance of the different architectures and to elucidate the effects of channel topology and coolant thermophysical properties. A quantitative sensitivity analysis is further conducted to identify the parameters governing cooling performance, while mesh-independence tests and comparisons with established empirical correlations are used to assess the reliability of the numerical model. The results show that the introduction of Fe 3 O 4 nanofluids consistently improves the overall thermo-hydraulic performance, with all nanofluid cases yielding PEC values greater than unity. Among the configurations investigated, the SIDO architecture provides the most favorable overall thermo-hydraulic performance, benefiting from effective flow distribution and enhanced heat transfer with moderate pressure losses. Although the BSIDO configuration produces stronger local convective heat transfer, the repeated flow separation induced by the wavy channels results in substantially higher hydraulic losses, limiting its overall performance