Numerical Investigation of Heat Transfer and Pressure Drop in a Circular Microchannel Using SiO₂ Nanofluids

A numerical investigation was conducted to analyze the flow characteristics and heat transfer performance of a circular microchannel. using water and SiO₂+pure water nanofluids with volume fractions of 0.3%, 0.7%, and 1%. The microchannel was subjected to a constant heat flux of 100W, and the pressure drop, friction factor, and thermal resistance were evaluated for different Reynolds numbers ranging from 250 to 850. The results show that the addition of SiO₂ nanoparticles enhances the thermal performance of the microchannel by reducing the thermal resistance by up to 1.9% compared to pure water. However, the pressure drop increases with higher Np concentrations, reaching a maximum of 3485 Pa for the 1% volume fraction, with 5.8% increase in compare with water. The friction factor for nanofluid of volume fraction 1% increase in compare with pure water with 4.7%. The study demonstrates that SiO₂ nanofluids provide improved cooling performance while maintaining an acceptable pressure drop, making them suitable for advanced thermal management in microchannel systems.