Study of magnetic field frequency effect on the atomic and thermal behavior of paraffin/Cu nanostructure in a tube with non-connected rotating ribs

Abstract

This study uses molecular dynamics simulations to examine the effects of different external magnetic field frequencies on the atomic and thermal properties of a paraffin/copper composite in a tube with rotating ribs. A stable starting state was first achieved via a 10-ns equilibration phase, which produced a temperature of 300 K and kinetic and potential energies of 0.026 kcal/mol and 1.424 kcal/mol, respectively. Several important properties of the simulated atomic sample were found to be dramatically changed when the external magnetic field frequency increased from 0.1 to 0.5 fs⁻¹. The highest atomic velocity decreased somewhat from 0.00499 to 0.00490 Å/fs, whereas the maximum density increased significantly from 0.0842 to 0.0847 atom/ų. Furthermore, the highest temperature of the system decreased from 775 to 758 K, suggesting a decrease in thermal energy associated with the higher frequencies. Alongside this shift, the heat flow decreased from 5.68 to 5.60 W/m², indicating changes in the properties of thermal transport. Additionally, thermal conductivity decreased from 0.79 to 0.71 W/m·K. It seems that the material increased more sensitivity to magnetic fields at higher frequencies since the charging time increased from 6.06 to 6.18 ns. The phase change material’s discharge time increased from 7.11 to 7.15 ns when the external magnetic field frequency increased from 0.1 to 0.2 fs⁻¹. It is interesting to note that a little increase in frequency to 0.3 fs⁻¹ caused the discharge time to decrease to 7.14 ns; nevertheless, when the frequency increased to 0.5 fs⁻¹, the discharge time increased once again and stabilized at 7.15 ns.