Magnetohydrodynamics of nanofluid internal forced convection: A review and outlook for practical applications

Nanofluids (NFs) have emerged as a revolutionary medium for enhancing heat transfer, with magnetohydrodynamics (MHD) gaining particular attention for its potential to improve system efficiency. Despite this growing interest, a critical gap remains in understanding the combined impact of Fe3O4 and its hybrid nanofluids under magnetic fields, especially in turbulent and transition flow regimes of internal forced convection. This review offers an in-depth exploration of MHD-NF internal forced convection, addressing key aspects such as magnetic field dynamics, nanoparticle clustering, stability, dispersion, flow control, and responsive rheology. Leveraging a comprehensive bibliographic analysis of 100 experimental studies from 2010 to the 2024, along with data from the Scopus® database, this work highlights how optimized nanofluid volume concentrations, magnetic field intensities, and frequencies significantly enhance heat transfer coefficients. The findings underscore that both magnetic field strength and nanoparticle concentration critically influence particle motion, flow patterns, entropy generation, thermal performance, and pressure drops, offering new insights into system design. The versatility of MHD-NF systems presents promising applications in fields ranging from advanced cooling technologies to solar thermal systems and material processing. Furthermore, this review addresses ongoing debates on the efficacy of alternating versus constant magnetic fields, advocating for customized magnetic field configurations to unlock the full potential of MHD-enhanced heat transfer. This work not only identifies existing gaps but also lays the foundation for future breakthroughs in magnetically influenced nanofluid systems.