Experimental investigation of the effect of magnetic field placement on pressure drop, entropy generation, heat transfer, and thermal performance of Fe3O4/TiO2 magnetic nanofluids in turbulent flow

Abstract

Utilizing magnetic fields to manipulate fluid motion in ferrofluids has become a crucial approach for improving heat exchange efficiency in thermal applications, especially in pipe systems. This research conducts an experimental analysis of the effects of magnetic field (MF) patterns on heat transfer, entropy production, and the thermal efficiency of /Ti magnetic hybrid nanofluids (MHNFs) operating under turbulent flow regimes. Key parameters explored include nanoparticle concentration, effect of magnetic field placement, and signal waveform types (square, sine, and triangular). Results demonstrate that lower nanoparticle concentrations (0.0125–0.1 vol%) significantly improve thermal performance compared to deionized water and higher concentrations. The square waveform yielded the highest heat transfer enhancement (28.21 %), followed by sine (27.87 %) and triangular waveforms (22.81 %). Additionally, entropy generation was minimized through optimized magnetic field application and placement, highlighting its critical role in improving heat transfer efficiency. The thermal performance (TP) peaked at 26.33 % enhancement with 0.0125 vol%, while lower pressure drops were observed at 0.0125 vol% to be 7.67 %, and 0.00625 vol%, corresponding to 10.29 %. This study introduces a novel approach to optimizing heat transfer systems by integrating magnetic field waveform placement with precise nanoparticle formulations. The findings have significant implications for advancing energy-efficient cooling systems in thermal management applications, offering enhanced heat transfer with reduced energy losses.