The effect of copper oxide nanoparticles on the thermal behavior of silica aerogel/paraffin as a phase change material in a cylindrical channel with molecular dynamics simulation

Abstract

The thermal conductivity of phase change materials was substantially enhanced by nanoparticles, improving the overall performance of thermal energy storage systems through more efficient heat transfer during the phase change process. This study investigates the effect of varying amounts of copper oxide nanoparticles on the thermal behavior of silica aerogel/paraffin as a phase change material in a cylindrical channel. LAMMPS and molecular dynamics simulations were employed to analyze this using a computer program. Results show that the atomic sample density and velocity reached 0.1393 Å³ and 0.0119 Å/fs, respectively, with the addition of 5% nanoparticles to the target structure. The atomic samples also reached a maximum temperature of 635 K when 5% of nanoparticles were added. The heat flux and thermal conductivity increased from 66.43 W/m² and 1.74 W/m·K to 71.25 W/m² and 1.82 W/m·K with a CuO-NP concentration increase of 3%. Adding nanoparticles enhanced thermal conduction, improving the overall interaction between the PCM and the nanoparticles. This led to better thermal contact and reduced thermal resistance at interfaces. However, adding more nanoparticles may lead to agglomeration, where the nanoparticles cluster together instead of remaining evenly dispersed. This can negatively affect thermal properties, as agglomerated particles create larger voids in the material, reducing the effective contact area for heat transfer. Using molecular dynamics simulations provided valuable insights into optimizing nanoparticle concentration for improved thermal performance in energy storage applications.