CylMesh

A mesh generator for cylindrical multilayer structures using Gmsh, designed for finite element simulations.

Features

• Complete mesh information: Returns vertex counts, element counts, and physical group details
• Clean naming: Surfaces named as FM1_bottom, FM1_top; volumes as FM1, Spacer, etc.
• Multiple interfaces: Python API and command-line tool
• Flexible configuration: JSON config files or direct parameters

Installation

Requires Gmsh to be installed.

git clone https://github.com/afanto/cylmesh.git
cd cylmesh
pip install . # or ./install.sh

Quick Start

Python API

from cylmesh import create_mesh, print_mesh_summary

# Create mesh with layer names
result = create_mesh(
    ml=2.0,
    radius=10.0,
    layers=[2.0, 1.0, 1.5],
    layer_names=["FM1", "MgO", "FM2"],
    output_name="device"
)

# Display comprehensive mesh information
print_mesh_summary(result)

Command Line

# Generate mesh with detailed output
cylmesh --ml 2.0 --radius 8.0 --layers 1.0 0.9 1.5 \
        --layer-names FM1 MgO FM2 --mesh device.msh

Both interfaces display:

• Vertex count (number of degrees of freedom for FEM)
• Element count (tetrahedral elements)
• Physical groups (surfaces and volumes with tags)

API Reference

create_mesh(ml, radius, layers, **kwargs)

Parameters:

• ml (float): Characteristic mesh length (nm)
• radius (float): Cylinder radius (nm)
• layers (list): Layer thicknesses (nm)
• layer_names (list, optional): Names for layers
• subdivisions (list, optional): Vertical subdivisions per layer
• output_name (str, optional): Base name for output files

Returns: Dictionary containing:

• success (bool): Whether mesh generation succeeded
• parameters (dict): All input parameters used
• geo_file, msh_file (str): Output file paths
• geo_size, msh_size (int): File sizes in bytes
• mesh_info (dict): Mesh statistics including:
  • num_vertices (int): Number of vertices/nodes
  • num_elements (int): Number of tetrahedral elements
  • physical_groups (dict): Surface and volume information

create_mesh_from_config(config_file, **kwargs)

Load parameters from JSON configuration file.

Config file format:

{
    "ml": 3.0,
    "radius": 15.0,
    "layers": [3.0, 1.0, 2.0],
    "layer_names": ["FM1", "MgO", "FM2"],
    "subdivisions": [2, 1, 1]
}

print_mesh_summary(result)

Pretty-print mesh generation results with organized output showing surfaces, volumes, and mesh statistics.

Physical Group Naming

Surfaces:

• Bottom: {first_layer}_bottom (e.g., FM1_bottom)
• Tops: {layer}_top (e.g., FM1_top, MgO_top, FM2_top)
• Default (no names): 1_bottom, 1_top, 2_top, etc.

Volumes:

• Named: FM1, MgO, FM2
• Default: 1, 2, 3

Command Line Options

cylmesh --ml FLOAT --radius FLOAT --layers FLOAT [FLOAT ...]
        [--layer-names STR [STR ...]]
        [--subdivisions INT [INT ...]]
        [--config FILE] [--mesh FILE] [--geo FILE]
        [--no-run] [--gui] [--verbose]

Use cylmesh --help for complete option details.

Requirements

• Python 3.8+
• Gmsh 4.8+

License

MIT License