Uniform Refinement

Uniform Refinement#

Uniform refinement creates regions of consistent mesh resolution, particularly useful for capturing off-body flow features such as wakes, shocks, and vortices, while maintaining computational efficiency in regions of uniform flow.

Available Options#

Option

Description

Spacing

Target mesh spacing in the region

Assigned boxes and cylinders

Target volumes for refinement application

Detailed Descriptions#

Spacing#

Defines the uniform mesh spacing within the refinement region.

  • Required

  • Example: 0.1 m

Note: Should be chosen based on flow feature size and resolution requirements.

Assigned boxes and cylinders#

Specifies the volumes where uniform refinement will be applied.

  • Required

Notes:

  • Must reference valid box or cylinder entities in the geometry.

  • Assign the entity by selecting from the list using the + button or select graphically in the viewer region.

Effect on the surface mesh#

Whether a uniform refinement also refines the surface mesh inside the region depends on the mesher:

  • The Geometry AI and snappy surface meshers refine the surface inside the region.

  • The legacy and beta surface meshers refine the volume mesh only, leaving the surface untouched.

With snappy, this is controlled per refinement by the project to surface option (on by default); turn it off to refine the volume only. The option is not available for the other meshers.

See also

User guide: Volumetric refinements: effect on the surface mesh

❓ Frequently Asked Questions

  • What happens if uniform refinements overlap?

    The finest (smallest) spacing will be applied in overlapping regions.

  • Can I specify a uniform refinement over a custom volume?

    Not over a fully user-defined custom volume directly. The recommended practice is to cover the target region with one or more overlapping primitive shapes (boxes/cylinders) and apply the uniform refinement to those. For example, an L-shaped region can be covered by two overlapping boxes.

🐍 Python Example Usage

See also

Python API:

import flow360 as fl

# Wake region refinement
wake_ref = fl.UniformRefinement(
    name="wake_region",
    entities=[wake_box],
    spacing=0.1 * fl.u.m
)

# Shock region refinement
shock_ref = fl.UniformRefinement(
    name="shock_region",
    entities=[shock_box],
    spacing=0.05 * fl.u.m  # Finer spacing for shock resolution
)

# Near-body refinement
near_body_ref = fl.UniformRefinement(
    name="near_body",
    entities=[near_body_box],
    spacing=0.02 * fl.u.m  # √3 times surface spacing
)
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