Comparative studies on heat transfer and flow resistance of nanofluid in microchannels with different sidewall micro-fins

The increasing integration of chips necessitates improved heat dissipation solutions, which has promoted the development and combination of nanofluids and microchannels. However, balancing heat transfer enhancement and flow resistance remains challenging. Hence, firstly, five different sidewall micro-fins in microchannels were designed, and then, mixture model was used to simulate the Al2O3-water nanofluids, which was followed by establishing a CFD model to investigate the effects of different micro-fins on the flow and heat transfer properties in microchannels. Results show that microchannels with micro-fins were significantly superior to smooth ones, achieving higher Nusselt numbers (Nu). The isosceles triangular micro-fin exhibits the highest Nu and reduced pressure drops by up to 16.1% compared to the rectangular micro-fin. Field synergistic theory analysis revealed that microchannels with isosceles triangular and trapezoidal micro-fins achieved the greatest reduction in synergistic angles, indicating improved synergy between flow and heat transfer.