A Navier‐Stokes‐Korteweg Model for Dynamic Wetting based on the PeTS Equation of State

Abstract

Dynamic wetting of component surfaces can be investigated by finite element phase field simulations. Often these models use a double‐well potential or the van der Waals equation to define the local part of the free energy density at a point of the computational domain. In order to give the present model a stronger physical background the molecular dynamics based perturbed Lennard‐Jones truncated and shifted (PeTS) equation of state is used instead. This results in phase field liquid‐vapor interfaces that agree with the physical density gradient between the two phases. In order to investigate dynamic scenarios, the phase field description is coupled to the compressible Navier‐Stokes equations. This coupling requires a constitutive equation that complies with the surface tension of the liquid‐vapor interface resulting from the PeTS equation of state and is comparable to the so‐called Korteweg tensor.