Enhancing the thermal performance of TiO₂/water nanofluids flowing in a helical microfin tube

A hybrid method with a microfin tube and TiO₂/water nanofluid with various nanoparticles concentration has been investigated experimentally. The objectives of this work are to characterize thermohydraulic including friction factor and thermal performance, and to develop correlation based on the experimental result. In general, adding nanoparticles to the base fluid causes increased thermal performance. Pressure drop inside the microfin tube at TiO₂/water concentrations of 0.05, 0.15, and 0.30 vol% were respectively 73%, 77%, and 80% higher than that in the smooth tube. Furthermore, the pressure drop increased with an increment in Re number. In this work, the developed correlation was proposed to predict practically Nu number. The present findings contribute to our understanding of how to enhance heat transfer using helical microfins inside tubes and nanofluids.