Domain Setup¶

The domain defines the region of space that will be meshed. Different simulation types require different domain configurations. Domain setup is done in the Setup tab of your project workspace.

Domain Types¶

External Flow¶

For simulating flow around an object — vehicles, aircraft, buildings, bluff bodies.

Studio generates a Cartesian bounding box (wind tunnel) around your geometry with configurable padding:

Parameter	Description	Default
Upstream	Distance ahead of geometry	1.5× geometry length
Downstream	Distance behind geometry (wake capture)	3.0× geometry length
Side (left/right)	Lateral distance	1.5× geometry width
Top	Distance above	2.0× geometry height
Bottom	Distance below	0× (geometry on ground)

Options:

Ground plane — Places the geometry on a flat ground surface. Essential for vehicle aerodynamics where ground effect matters.
Symmetry plane — Meshes only half the domain and mirrors results. Halves compute cost for symmetric geometries.

Tip

For vehicle aerodynamics, use a ground plane and ensure the bottom padding is 0 so the car sits on the ground. For aircraft, increase the bottom padding to avoid ground interference.

When you select External Flow, Studio creates the surrounding flow domain, assigns standard domain boundary names, and prepares the mesh controls for the volume outside the geometry.

Internal Flow¶

For simulating flow inside a geometry — pipes, ducts, manifolds, enclosures, HVAC systems.

The domain is defined by the interior volume of your geometry. Studio automatically:

Identifies the fluid volume enclosed by the surfaces
Detects inlet and outlet faces (the open ends of the geometry)
Sizes the mesh based on the smallest internal dimension

When you select Internal Flow, Studio identifies the intended fluid volume, assigns inlet and outlet surfaces where possible, and prepares interior walls as boundary patches.

Note

For internal flow geometries, the geometry must be watertight except at the intended inlet and outlet openings. Any gap in the surface other than at inlets/outlets will allow fluid to escape the domain and cause the mesher to fail to identify the correct interior.

Rotating Machinery¶

For rotating equipment — fans, pumps, turbines, compressors, propellers.

This domain type creates:

A rotating zone around the moving geometry (MRF — Multiple Reference Frame)
A stationary zone for the surrounding fluid
An interface between the zones

Configure the rotation axis, speed (RPM), and zone dimensions in the Setup tab.

Studio uses the rotating zone definition to prepare the mesh regions and interface settings needed by the selected rotating-machinery workflow.

Conjugate Heat Transfer (CHT)¶

For problems involving heat exchange between fluid and solid regions, such as heat sinks, cold plates, and thermal-management assemblies.

CHT domain setup requires:

At least two regions (one fluid, one solid)
Properly defined interfaces between touching regions
Material properties for each region

Solid Body¶

For meshing the interior of a solid geometry — used for thermal analysis or structural simulations without fluid flow.

Domain Shapes¶

The enclosing domain can take different shapes depending on your application:

Shape	Best For
Box	Vehicle aerodynamics, buildings, general external flow
Cylinder	Axisymmetric bodies, rotors, vertical structures
C-Domain	Airfoils and 2D-like aerodynamics
O-Domain	Cylinders, cables, circular cross-sections

Configuring the Domain¶

Automatic Sizing¶

When you select a domain type, Studio automatically sizes the domain based on your geometry’s bounding box. The defaults work well for most cases.

Manual Adjustment¶

You can adjust the domain in two ways:

Numerical input — Enter exact dimensions in the Setup panel
3D viewer — Drag the domain box handles directly in the viewer

Domain Visualization¶

The domain boundary appears as a semi-transparent box in the 3D viewer. You can:

See the geometry positioned within the domain
Verify adequate clearance on all sides
Check that the domain is large enough to avoid boundary interference

Domain Size Guidelines

Too small: Boundary effects contaminate the solution. Flow doesn’t develop properly before hitting the outlet.

Too large: Wastes cells on far-field regions, increasing compute cost without improving accuracy near the geometry.

The defaults strike a good balance for most applications. Increase downstream distance for bluff bodies with large wakes.

Named Selections¶

Named selections (also called boundary patches) are how Studio identifies different surface regions for boundary condition assignment. When you generate a mesh, every face on the domain boundary belongs to a named selection.

Studio automatically creates named selections for domain boundaries:

Named Selection	External Flow	Internal Flow
`inlet`	Upstream face of the domain box	Open inlet face(s) of the geometry
`outlet`	Downstream face of the domain box	Open outlet face(s) of the geometry
`top`	Top face of the domain box	—
`side_left`, `side_right`	Side faces	—
`ground`	Bottom face (if ground plane enabled)	—
`symmetry`	Symmetry cut plane (if enabled)	—
Geometry surfaces	Automatically from CAD face names	Interior walls

You can view and rename all named selections in the Surfaces tab. See Surfaces for full details.

Meshing Time¶

Once you click Generate Mesh, the job is submitted for cloud execution. Typical generation times:

Mesh Size	Typical Time
< 5 million cells	1 – 3 minutes
5 – 20 million cells	3 – 8 minutes
20 – 100 million cells	8 – 30 minutes
> 100 million cells	30 minutes – 1 hour

These are approximate. Actual time depends on:

Geometry complexity — More surface features and curvature require more mesh work.
Refinement depth — More refinement increases cell count and generation time.
Number of refinement zones — Each zone adds local resolution requirements.
Domain size — Larger domains require more cells at the same resolution.

Tip

Use coarse meshes for setup checks, then refine once the domain, surfaces, and boundary conditions are correct.

You can monitor meshing progress and intermediate cell counts in the Logs panel.