The Atomic and Thermal Performance of CuO Nanoparticles/Paraffin as Phase Change Materials in a Circular Tube: Molecular Dynamics Simulation Approach

Abstract

Background: Using molecular dynamics simulation, this study investigates the effect of CuO nanoparticle addition on the thermodynamic and atomic properties of an octadecane that was being utilized as a phase change material within a circular tube. Methods: The results indicate that the density (D) was greatest in the vicinity of the tube walls. At its peak, D was 0.0300 atoms per square centimeter. This behavior is due to the increased attractive force that is between the structure's boundaries and its particles. Particle velocity (V) values reached their utmost attainable values in the intermediate regions of the tube, where movement was greatest. At its peak, V was 0.0078 Å/fs. The tube exhibits a maximum temperature (Max T) value of 754.43 K at its midpoint. Significant Findings: Due to the increased particle motion in the intermediate regions, the investigated structure experienced a greater number of collisions in those areas. After 10 ns, the sample's heat flux, thermal conductivity, and thermal stability converged to values of 3.94 W/m2, 1.38 W/mK, and 1821 K, respectively. The structure showed charging and discharging times of 6.41 and 7.15 ns, respectively. © 2025 Elsevier B.V.