Structured meshing

The goal is to create a structured equidistant hexahedral cartesian mesh for calculations of foam properties.

Inputs

Required inputs are the *TessellationBox.stl file, which is created by tessellation generation process (see Tessellation), and target foam porosity and strut content, which can be provided through CLI or configurational file.

Execution

Default mesh can be created by running:

foamgen -s

This produces *SMesh.vtk file similar to this one:

Outputs

By default the mesh is saved in VTK format (*SMesh.vtk). It can be viewed with Paraview.

Implementation

Geometrical morphology is not used for structured meshing at all. Foam morphology is created on the equidistant grid. The walls are created using binvox program, which marks all voxels intersected by tessellated surface as solid voxels. Thus, wall thickness is always 1-2 voxels. Desired foam porosity is achieved by scaling the computational domain - more voxels in each direction lead to higher ratio of cell to wall voxels, and thus to higher porosity. Struts are created by foamreconstr program, which adds triagonal prism along each edge and marks the voxels within. Root finding method is employed to find the correct domain and strut size.

Note that high porosity and high strut content lead to large domain sizes, which is very time and memory consuming.