A Novel Slip Boundary Condition for Contact Angle Modeling Using Phase-Field Methods*

This work introduces a novel slip boundary condition designed to enforce a given contact angle in phase-field simulations. Unlike traditional methods, which typically alter the mass transport equation or impose an arbitrary Navier-slip boundary condition, this approach is motivated from a momentum balance at the wall. This physics-based boundary condition enables the seamless integration of contact angle physics into phase-field simulations. In this talk, the boundary condition, which takes the form of a PDE that is advanced discretely in time, is derived and results are shown for various static contact angles. Following this, the boundary condition is coupled with various pre-existing models for the dynamic contact angle. Results for a drop sliding down an inclined plane are then shown.