README.md

brep_to_h5m

A Python package that converts Brep CAD geometry files to h5m geometry files compatible with DAGMC simulations.

The method uses gmsh to create a conformal mesh of the geometry and then exports separate volumes to STL files. The stl-to-h5m package then converts the non overlapping STL files into a h5m geometry.

Installation (Conda)

Create a new enviroment and activate the enviroment.

conda create --name my_env
conda activate my_env

Then install this package

conda install -c fusion-energy -c conda-forge brep_to_h5m

The above command should also install moab and gmsh

Installation (Conda + pip)

Create a new enviroment and activate the enviroment.

conda create --name my_env
conda activate my_env

Install dependancies that are not installed with pip (MOAB and GMSH)

conda install -c conda-forge moab
conda install -c conda-forge gmsh
conda install -c conda-forge python-gmsh

Then install this package

pip install brep_to_h5m

Usage

See the examples folder for a complete workflow from geometry creation to conversion to h5m and then use in and OpenMC simulation.

To make a Brep file with merged surfaces consider using the Paramak as it has a export_brep method that merges the shared surfaces for Brep files.

Starting with a Brep file that has shared surfaces the following command should produce a DAGMC compatible h5m file.

from brep_to_h5m import brep_to_h5m

brep_to_h5m(
    brep_filename='my_brep_file_with_merged_surfaces.brep',
    volumes_with_tags={
        1: 'material_for_volume_1',
        2: 'material_for_volume_2',
        3: 'material_for_volume_3',
        4: 'material_for_volume_4',
        5: 'material_for_volume_5',
        6: 'material_for_volume_6',
        7: 'material_for_volume_7',
        8: 'material_for_volume_8',
    },
    h5m_filename='dagmc.h5m',
    min_mesh_size= 30,
    max_mesh_size = 50,
    mesh_algorithm = 1,
)

The resulting dagmc.h5m file can now be used in neutronics simulation with DAGMC enabled transport codes.

Acknowledgement

Many thanks to @makeclean for suggesting gmsh for meshing and Brep for the CAD file format. Also for showing the way forwards by starting gmsh2dagmc.