LS-DYNA ICFD *MESH_BL card

[Guillaume RENEDO]

Dear all,

I use the LS-DYNA ICFD module to perform CFD simulations applied to intracranial arteries.

I am currently conducting a mesh convergence study.

I perform surface meshing using Tetgen embedded in VMTK.

I then let LS-DYNA perform volume meshing based on the surface mesh.

For the implementation of boundary layers, Tetgen uses coefficients and ratios (sublayer ratio, boundary layer thickness factor) for the meshing of prismatic elements.

In LS-DYNA, the *MESH_BL card offers automatic boundary layer meshing with NELTH+1 layers when the default settings are selected.

Two questions:

1) I would like to know if it is possible to set a factor to calculate the boundary layer thickness rather than having to set an exact thickness in mm, cm or m via BLTH, BLFE and BLST.

2) What coefficients are used by *MESH_BL in the automatic inflation of boundary layers?

Thank you,

Guillaume