A High-Order Numerical Method for Wetting, Dewetting and Heat Transfer*

The present project was motivated by an experiment in which a heated wall is dragged out of a liquid reservoir with a certain dewetting velocity and wall superheat. For small ratios of dewetting velocity to wall superheat, evaporation occurs mainly in the vicinity of the three-phase contact line. If the dewetting velocity is raised further, the so-called microlayer evaporation (as opposed to contact line evaporation) can be observed experimentally. This is characterized by the formation of an eponymous microlayer of liquid in which evaporation occurs.

For a highly accurate representation of this flow we have developed a high order eXtended Discontinuous Galerkin (XDG) method for the simulation of such wetting/dewetting phenomena, subject to mass and heat transfer at the liquid-vapor interface. The usage of XDG allows, together with a level-set based interface capturing technique, for a sharp representation of the liquid-vapor interface. One key advantage of this method is the ability to directly capture jumps/kinks in the solution at the interface.

Through our method we are able to investigate the microlayer evaporation regime. However, when transitioning into the contact line evaporation regime, some issues with numerical stability of the interface still remain.