surfaceDisplacement

Description

The surfaceDisplacement is a boundary condition that provides displacement fixed by projection onto triSurface. Use in a displacementMotionSolver as a boundary condition on a pointDisplacement field.

Usage

The condition requires entries in both the boundary and field files.

Boundary file

<patchName>
{
    type            patch;
    ...
}

Field file

<patchName>
{
    // Mandatory entries
    type            surfaceDisplacement;
    velocity        <vector>;
    geometry        <dict>;
    projectMode     <word>;
    projectDirection  <vector>;

    // Optional entries
    wedgePlane      <label>;
    frozenPointsZone  <word>;

    // Inherited entries
    ...
}

where:

Property	Description	Type	Required	Default
type	Type name: surfaceDisplacement	word	yes	-
velocity	Maximum velocity	vector	yes	-
geometry	Dictionary with searchableSurfaces. (usually triSurfaceMeshes in constant/triSurface)	word	yes	-
projectMode	Projection mode	word	yes	-
projectDirection	Projection direction	vector	yes	-
wedgePlane	-1 or component to knock out of intersection normal	label	no	-1
frozenPointsZone	Empty or name of pointZone containing points that do not move	word	no	null

Options for the projectMode entry:

Property	Description
NEAREST	Nearest
POINTNORMAL	Intersection with point normal
FIXEDNORMAL	Intersection with fixed vector

The inherited entries are elaborated in:

• fixedValuePointPatchField.H

• This displacement is then clipped with the specified velocity*deltaT.
• Optionally (intersection only) removes a component (wedgePlane) to stay in 2D.

Further information

Tutorial:

• SnakeRiverCanyon

Source code:

• surfaceDisplacement

API:

• Foam::surfaceDisplacementPointPatchVectorField

History: Introduced in version 1.6