Development and Deployment of Diffuse Interface Phase-Field Methods in OpenFOAM

We have developed a unified solver framework for two-phase flow based on diffuse-interface phase-field methods [1], which is to be released within the FOAM-extend project. In contrast to standard sharp interface model approaches, phase-field methods rely on diffuse interface models. As their name suggests, these methods allow for diffusion of the phase constituents in a thin interfacial region of well-defined thickness, thus, promoting a smooth but rapid transition of phase properties such as density and viscosity. To this extend, the new solver phaseFieldFoam has been massively validated for wetting processes including patterned and porous substrates. Particularly, capillary-dominated two-phase flow can be dealt with at high accuracy, i.e. parasitic currents are found to be low and consistently converging under mesh refinement [2].

The present work focus on droplet impact and impingement scenarios at high dynamics. Recent simulations for both droplet impact on thin liquid films of the same fluid, and droplet impingement and bouncing on a heated hydrophobic surface show very good agreement with experiments. The talk will detail on necessary method enhancements to achieve this.

Acknowledgments --------------- Funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) – Project-ID 237267381 - SFB TRR 150.

References ---------- [1] X. Cai, H. Marschall, M. W¨orner, and O. Deutschmann, “Numerical Simulation of Wetting Phenomena with a Phase field Method using OpenFOAM,” Submitted, 2015. [2] F. Jamshidi, H. Heimel, M. Hasert, X. Cai, H. Marschall, and M. W¨orner, “On suitability of phase-field and algebraic Volume-Of-Fluid OpenFOAM solvers for gasliquid microfluidic applications,” Comput. Phys. Commun., vol. 236, pp. 72–85, 2019.