The effect of external force and magnetic field on atomic behavior and pool boiling heat transfer of Fe3O4/ammonia nanofluid: A molecular dynamics simulation

Background: In this study, the pool boiling heat transfer of Fe3O4 /ammonia nanofluid in a copper (Cu) nanochannel is done using the molecular dynamics (MD) simulation.Methods: To increase and improve the performance of heat transfer, the effect of external force, and external magnetic field frequency on the atomic and thermal performance of the simulated nanostructure was checked. The results show that the density increased with a positive slope when the external force was imposed on the nanostructure with a growing trend. The amount of velocity and temperature similarly increased. So, by increasing the external force from 0.001 to 0.005 eV/angstrom, the maximum values of density, velocity, and temperature converge to the values of 0.1441 atom/angstrom 3, 13.939 angstrom/fs, and 794.61 K. Moreover, increasing the applied external force caused an increase in the heat flux and thermal conductivity in the nanostructure. Finally, studying the effect of external magnetic field on the nanofluid's atomic behavior shows that with the change in the frequency of external magnetic field, Poiseuille behavior was remained. The results of the increase in the frequency of external magnetic field show the increasing trend of velocity and temperature. Numerically, the maximum values of velocity and temperature increase from 7.133 to 11.476 angstrom/fs, and from 210.23 to 410.07 K, respectively. Furthermore, HF increases by increasing the frequency of external magnetic field.Significant findings: As particles' movement increased, the structure's thermal resistance decreased. So, by increasing external force, the thermal resistance in the structure decreased.

Automated summary

In this study, pool boiling heat transfer of Fe3O4/ammonia nanofluid in a copper nanochannel was investigated using molecular dynamics (MD) simulation. The results showed that the density, velocity, and temperature increased with the application of external force on the nanostructure, which also led to an increase in heat flux and thermal conductivity. Additionally, the frequency of the external magnetic field affected the behavior of the nanofluid, with an increase in frequency resulting in higher velocity, temperature, and thermal resistance.