Free Surface

BC_Type = FreeSurface: This boundary imposes zero normal velocity at the surface.

Syntax for this boundary condition:

FreeSurface Boundary_Name { ( Temperature Tfs | HeatFlux = qfs | ConvCoeff = hc, ConvTref = Tinf ) }

Variable Name	Description	Valid Data Types
Temperature (Tfs)	Static temperature	CONSTANT, EXPRESSION f(x,y,z,t)
HeatFlux (qfs)	Magnitude of surface heat flux	CONSTANT, EXPRESSION f(x,y,z,t)
ConvCoeff	Convective heat transfer coefficient	CONSTANT, EXPRESSION f(x,y,z,t)
ConvTref	Outside temperature	CONSTANT, EXPRESSION f(x,y,z,t)

If MeshUpdate analysis is being done, the FreeSurface boundaries are allowed to move to remain tangent to velocity vectors.