Predicting Phase-Transition in Phase Change Materials Slurries: A Molecular Simulation Approach

Abstract

Molecular dynamics simulations were performed to investigate the phase-transition behavior and thermophysical properties of octadecane–water phase-change slurries across the solid–liquid transition range of the paraffin phase. Octadecane was used as a model system to assess the capability of the method to describe phase transitions at the molecular level. Diffusion coefficients, radial distribution functions, specific volume, rotational time correlation functions, and thermal conductivity were systematically evaluated as functions of temperature. All descriptors consistently identified the transition between 308 and 318 K, confirming the coherence of the simulation framework. Although the simulated transition temperature was slightly higher than experimental values, the expected thermophysical trends were accurately reproduced, demonstrating that molecular dynamics is a reliable tool for analyzing and optimizing phase-change materials for thermal energy storage applications.