[azad_786]

Hello OpenFOAM Community,

I am working on implementing dynamic mesh motion for a case in OpenFOAM-extend 4.0.
My objective is to enable displacement-based mesh adjustments using displacementLaplacian with dynamicMotionSolverFvMesh.
However, I have been encountering persistent issues, particularly with configuring diffusivity in the dynamicMeshDict file.

Implementation Strategy:
Solver Modification: My setup involves modifying the solver to handle dynamic mesh operations, specifically by applying dynamicFvMesh (later extending to dynamicMotionSolverFvMesh). solver compiles
Mesh Motion Solver: I have e selected displacementLaplacian as the motion solver within dynamicMotionSolverFvMesh to manage displacement-based mesh modifications.

ERROR:

Create dynamic mesh for time = 0

Selecting dynamicFvMesh dynamicMotionSolverFvMesh
Selecting motion solver: displacementLaplacian


--> FOAM FATAL IO ERROR:
keyword diffusivity is undefined in dictionary "/home/app/foam/app-4.0/sharedRun/foamcases/mesh_moving_directional/1_planar_case/constant/dynamicMeshDict"

file: /home/app/foam/app-4.0/sharedRun/foamcases/mesh_moving_directional/1_planar_case/constant/dynamicMeshDict"t from line 11 to line 24.

From function dictionary::lookupEntry(const word&, bool, bool) const
in file db/dictionary/dictionary.C at line 395.

FOAM exiting
my constant/dynamicmeshdict file looks like this
FoamFile
{
version 2.0;
format ascii;
class dictionary;
location "constant";
object dynamicMeshDict;
}

// Load the necessary library
libs ("libfvMotionSolvers.so");

// Specify the type of dynamic mesh
dynamicFvMesh dynamicMotionSolverFvMesh;

// Define the solver type
solver displacementLaplacian;

// Define the coefficients for the dynamic motion solver
dynamicMotionSolverFvMeshCoeffs
{
displacementLaplacianCoeffs
{
diffusivity uniform 1.0;
}
}

and 0/pointDisplacement;
FoamFile
{
version 2.0;
format ascii;
class pointVectorField;
location "0";
object pointDisplacement;
}

dimensions [0 1 0 0 0 0 0];
internalField uniform (0 0 0);
boundaryField
{
left
{
type fixedValue;
value uniform (0 0 0); // Fixed boundary with no movement
}
right
{
type uniformFixedValue;
uniformValue (4e-8 0 0); // Uniform displacement on the right boundary
}
up
{
type zeroGradient;
}
down
{
type zeroGradient;
}
frontAndBack
{
type empty;
}
}

If anyone has experience with configuring displacementLaplacian for dynamic mesh motion, please advice to fix this error.

Thank you

[Krapf]

The error message indicates that you are defining “diffusivity” in the wrong place. It does not belong in the "dynamicMotionSolverFvMeshCoeffs"/"displacementLaplacianCoeffs" subdictionary, but on the first level, like “dynamicFvMesh” and “solver”, for example. See also: https://github.com/Unofficial-Extend...icMeshDict#L23.

[azad_786]

Thank you so much. It worked