Magnetic field effects on the thermo-hydrodynamic behavior of a microscale Tesla valve operating with Fe3O4-water ferro-nanofluid

Despite their passive ability to resist reverse flow, Tesla valves can experience altered performance under external influences such as magnetic fields, which can alter or even disrupt the proper functioning of Tesla valves particularly in microscale systems in electronic devices. In this framework, the present study aims to investigate the influence of a horizontal magnetic field on the hydrodynamic and thermal performance of a T45-R microscale Tesla valve integrated into a microsystem. Using computational fluid dynamics (CFD), the effect of the magnetic field, modeled via the Hartmann number (Ha = 0–100), on a laminar (Re = 500) Fe3O4-water ferro-nanofluid flow has been analyzed under both forward and reverse flow conditions. The studied flow is governed by the mass, momentum, and energy equations, which has been solved numerically using the finite element method. The results indicate that the magnetic field significantly affects both flow directions, inducing a pressure difference that increases by nearly 150 % for moderate magnetic flux densities (Ha ≈ 25) compared to the non-magnetic case. In forward flow, increased magnetic flux density enhances flow intensity and heat transfer while partially blocking the curved part of the valve, yet it may inadvertently support reverse flow. Diodicity analysis has revealed that valve performance decreases for Hartmann numbers below Ha ≈ 17, independent of nanoparticle concentration, while it improves beyond this threshold. Nevertheless, optimal valve performance is still observed in the absence of a magnetic field.