Simulating two-phase flows using a thermodynamically consistent coupled Cahn-Hilliard Navier-Stokes framework*

We study the evolution of interfaces in two-phase flows with moderate density ratios.  We use a thermodynamically consistent coupled Cahn-Hilliard Navier-Stokes based formulation.  Mass conservation and energy stability is explicitly satisfied in the discrete formulation.  We use a finite element based spatial discretisation with the variational multiscale approach to solve the momentum equations.  We use a fast octree based adaptive meshing strategy which is massively parallel, thus allowing DNS of multiple droplets/bubbles in flow.  
We present a case study of droplet transport in microfluidic devices, with varying density ratios, interfacial tension, and viscosity ratios. The results are validated against high speed photography experiments.