Geometry and the computational domain

Vanellus divides the domain into fluid and solid regions. The geometry in cuboid_components and cad_components defines the solids; everything else inside the domain is fluid.

The domain

The domain supplies the physical bounds as an axis-aligned box:

• origin is its lower-corner position, ordered as [x, y, z] in meters.
• size is its dimensions, ordered as [x, y, z] in meters.

The axes have no inherent physical orientation; the gravity vector defines which direction is down. Use Set the computational domain to configure these bounds and axes.

Fluid and solid regions

The solid region is the combination of every entry in cuboid_components and cad_components. A component’s complete interior is solid and displaces fluid, regardless of its thermal_model.

Enclosed fluid regions are possible, but must be formed by separate solid components around them e.g. six thin cuboids forming a closed box. The space enclosed by those walls remains fluid because it is not inside a component. A single cuboid or enclosed CAD component cannot represent a hollow volume: its interior is solid.

Component geometry

cuboid_components are axis-aligned cuboid solids defined directly in domain coordinates. Their mesh is body-fitted to the cuboids. Use Add a cuboid component to define one.

cad_components are uploaded STEP or STL components with placement and sizing metadata. CAD voxelization turns their enclosed surfaces into solid cells, so features smaller than the local mesh may be lost. Use Add a CAD component to import one.

The geometry and sizing constraints are converted into one rectilinear mesh. That representation determines how component faces, CAD detail, and local refinement affect cells elsewhere in the domain.

See also

• Conducting and insulating domains explains which solid regions participate in the energy solve.
• Build an assembly from cuboids combines components into a complete model.
• API reference lists the domain and component fields.