Temperature dependent Korteweg stress coefficient from the Enskog–Vlasov equation

Abstract

Enskog–Vlasov equation—a nonlinear partial-integrodifferential equation, provides a robust framework for analyzing liquid dynamics and phase transition. The Vlasov force expanded using Taylor series yields Korteweg stress with two constant coefficients. The first coefficient yields the van der Waals like contribution to equilibrium pressure, while the second coefficient determines the interfacial stresses/surface tension. In this article, we express the second Korteweg constant coefficient as a function of temperature. The developed model effectively captures the liquid–vapor interfacial region in equilibrium, reproducing the sharp interfacial structure predicted by the full Enskog–Vlasov equation. Additionally, we compare our results with those obtained through a particle-based approach, as studied by Frezzotti et al. (2009) [“Direct simulation Monte Carlo applications to liquid–vapor flows,” Phys. Fluids 31, 062103 (2019)]. The proposed model balances simplicity with computational efficiency, comprehensively examined within the paper.