What is a blockMesh File?
The blockMesh file, or blockMeshDict, is a core configuration file in OpenFOAM used to define mesh geometries for Computational Fluid Dynamics (CFD) simulations. It is designed to create structured, hexahedral meshes for simple geometries like cubes, cylinders, or rectangular prisms. This file serves as the input to OpenFOAM’s blockMesh utility, which processes the instructions and generates the computational domain.
Why is blockMesh Important?
In CFD simulations, mesh quality and accuracy are critical for reliable results. With blockMesh, you can:
- Generate clean, structured meshes for simple geometries.
- Fully customize mesh density, grading, and boundary conditions.
- Control mesh refinement to optimize simulation performance.
By mastering blockMesh, users can build efficient meshes tailored to specific simulation needs.
The blockMeshDict file comprises several sections that define the mesh geometry and configuration:
Structure of blockMeshDict
//Vertices
//Specifies the coordinates of the mesh’s corner points.
//Example:
vertices
(
(0 0 0) // Bottom-left corner
(1 0 0) // Bottom-right corner
(1 1 0) // Top-right corner
(0 1 0) // Top-left corner
);
// Blocks
//Defines the hexahedral blocks and mesh resolution.
//Example:
blocks
(
hex (0 1 2 3 4 5 6 7) (10 10 10) simpleGrading (1 1 1)
);
//Edges (optional)
//Allows curved edges for complex geometries.
//Boundary
//Assigns names and types (e.g., walls, inlets, outlets) to the mesh boundaries.
//Example:
boundary
(
inlet
{
type patch;
faces
(
(0 4 7 3)
);
}
);
//mergePatchPairs (optional)
//Merges patches to ensure smooth connections between regions.
