Computational study of the thermal performance of water/Fe3O4 nanofluid in an oscillating heat pipe: A molecular dynamics approach

Recently, oscillating heat pipes (OHPs) filled with nanofluid (NF) as the operating fluid has drawn researchers' attention because of their improved thermal conductivity, and heat/mass transfer (HT/MT) characteristics. An OHP is an HT device based on a two-phase fluid flow that transfers heat between heat sources and heat sinks which is applicable in industries in terms of its highly effective thermal conductivity. According to previous research, in previous experimental and computational studies, the effect of adding metal oxide NPs into the operating fluid of an OHP was not studied. Therefore, adding Fe3O4 NPs to the operating fluid of the water flowing into an OHP with nano dimensions will be the research work ahead that can increase the efficiency of designed structures. The maximum density, velocity, temperature, and heat flux after 20 ns are examined to determine the effects of NP size and an external magnetic field (EMF). The numerical findings show that heat flux increased from 1561 to 1602 W/m2 when the NPs' size grew from 5 to 10. Therefore, the HT/MT of Fe3O4-H2O simulated NF showed enhanced thermal behavior as NP's radius increases. Furthermore, the results show that the presence of an EMF enhanced the thermal behavior of NF in the OHP. The heat flux increased from 1563 to 1586 W/m2 when the magnetic field magnitude increased from 1 to 5 T.(c) 2023 THE AUTHORS. Published by Elsevier BV on behalf of Faculty of Engineering, Alexandria University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/ licenses/by-nc-nd/4.0/).

Automated summary

Recently, oscillating heat pipes filled with nanofluid have attracted attention due to their improved thermal conductivity and heat/mass transfer characteristics. This study focuses on adding Fe3O4 nanoparticles to the nanofluid to enhance the efficiency of the designed structures. Numerical findings show that the thermal behavior of the Fe3O4-H2O nanofluid improves as the nanoparticle radius increases. Additionally, the presence of an external magnetic field enhances the thermal behavior of the nanofluid in the heat pipe.