The Wetted Wall node is the default boundary condition representing wetted walls. Along a wetted wall the contact angle for the fluid,
θw, is specified, and across it, the mass flow is zero. This is prescribed by
The contact angle θw can be defined directly or from Young’s equation, which considers the components of the forces in the plane of the surface:
where γs1 is the surface energy density on the fluid 1 — solid (wall) interface and
γs2 is the surface energy density on the fluid 2 — solid (wall) interface.
Select an option from the Specify contact angle list —
Directly (the default) or
Through Young’s equation. For
Directly enter a value or expression for the
Contact angle θw (SI unit: rad). The default value is
π/2 radians. For
Through Young’s equation enter values or expressions for
Phase 1-Solid surface energy density γs1 (SI unit: J/m
2) and
Phase 2-Solid surface energy density γs2 (SI unit: J/m
2).
The wetted wall condition is not available for the Phase Field Thin-Film Flow (pftff) interface for 2D problems.