Specified_Normal_Velocity

Syntax

Bc Flux For Mesh ([{of} SpeciesName] | [{in} MaterialPhaseName] | [{ls} {a | b | c}]) {@ | at | for | on | over} Mesh Extent Name ([Touching TouchingMeshExtent] | [Opposing OpposingMeshExtent]) = Specified_Normal_Velocity ([Toggle = toggle] | [Stiffness_Factor = stiffness_factor])

Summary

Penalized normal mesh velocity

Description

Enforces a weak specified normal velocity condition by applying a mesh flux of

\vec{F} = 2 \mu S_f \left( V_m - \dot{\vec{D}} \cdot \vec{n} \right) \vec{n}

Where 2 \mu is the mesh TWO_MU value, and S_f is the stiffness factor. The normal mesh velocity, V_m is provided by the NORMAL_MESH_VELOCITY expression on the surface (scalar, positive for outward mesh velocity).

The following options are present in most boundary conditions/sources. The meaning of each option is as follows:

Toggle

If given, specifies which toggle block controls whether this BC is active or not.

Parameter

Value

Default

{of}

{of | species | subindex}

–

SpeciesName

string

–

{in}

{in | material_phase}

–

MaterialPhaseName

string

–

{ls}

{levelset_phase | ls}

–

Mesh Extent Name

string

–

TouchingMeshExtent

string

–

OpposingMeshExtent

string

–

toggle

“string”

–

stiffness_factor

real

1e+06