TY - JOUR
TI - Modeling interfacial properties of multicomponent fluids at high pressures using density gradient theory and Peng-Robinson equation of state
AU - Yan Jing
AU - Peng Leqin
AU - Ye Ting
JN - Thermal Science
PY - 2025
VL - 29
IS - 5
SP - 3641
EP - 3655
PT - Article
AB - The interfacial properties of real systems consisting of complex mixtures are not easily accessible through experimentation. The density gradient theory coupled with the Peng-Robinson equation of state is applied here to predict the interfacial properties of the mixture, such as interfacial tension, interfacial thickness, and density profile within the interface, both far from and near the critical region. A modified algorithm has been developed to solve density gradient theory equations without the need to select the reference fluid or estimate the domain size by explicitly introducing the time-dependent molar density term. The approach accurately describes the interfacial tensions of mixtures compared to the available experimental data. Furthermore, based on the obtained density profiles and interfacial thicknesses, the transition between the vapor-liquid two-phase and single-phase of the multicomponent system is quantified using the Knudsen number criterion under high pressure conditions.