Investigation of the Atomic and Thermal Performance of Al2O3 Nanoparticles/Octadecane as Phase Change Materials (PCM) in Circular Tube With Molecular Dynamics Simulation

Abstract

Phase change materials' heat transfer mechanism may be enhanced by high thermal conductivity nanoparticles, allowing for quicker and more efficient thermal energy storage and release. This study examined the atomic and thermal characteristics of octadecane as a phase transition material inside a circular tube using molecular dynamics modeling with Al2O3 nanoparticles. At 0.031 (±0.002) atoms/Å3, the tube walls had the highest density after 20 ns. The tube's maximum recorded temperature was 751.51 (±1.01) K, and its peak velocity was 0.0078 (±0.0001) Å/fs. After 20 ns, the thermal conductivity was 1.35 (±0.01) W/m·K and the heat flux was 3.84 (±0.01) W/m2. The charging and discharging times of the structure were 6.45 (±0.05) and 7.15 (±0.03) ns, respectively. This study shows how AlO₃ nanoparticles can enhance the thermal performance of octadecane in energy storage applications. It also provided important information about the atomic-level behavior of these materials during phase transitions. © 2025 Elsevier Ltd