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Geometry Repair
Manage CAD, FE, and 2D parametric sketch geometry.
Discrete Geometry
Work with discrete geometry like FE Geometry and floating elements.
Create Derived Regions
Use the Derived Region tool to create enclosed and offset regions around a selection – which can be used to define volumetric refinement levels – or create projected regions in a given direction.

Welcome
What's New
View new features for HyperMesh CFD 2025.1.
Get Started
Learn the basics and discover the workspace.
Onboarding Resources
Discover HyperMesh CFD functionality with interactive tutorials and community resources.
Solution Layers
Solution-centric workflows allow you to traverse through modeling environments using a dedicated UI layer.
Manage Files and Data
Create, open, import, and save models.
Convert
Use the Convert tool to convert entire models between data types.
Geometry Repair
Manage CAD, FE, and 2D parametric sketch geometry.
- Sketching
  Create and edit 2D parametric sketch geometry.
- Geometry
  Create, edit, and cleanup geometry.
- Discrete Geometry
  Work with discrete geometry like FE Geometry and floating elements.
  - Cap Holes and Fill Gaps
    Use the Cap tools to close openings and gaps between parts/surfaces.
  - Connect Geometry
    Use the Connect tools to trim, fuse, and stitch your discrete geometry.
  - Enclosure
    In CFD modeling, input parts can have topology issues, like free surfaces and self-intersections, and part assembly issues, such as parts with very close proximity and intersecting parts. Manually connecting these parts can be time consuming and require expertise in certain tools. The Enclosure tool can generate a watertight manifold model from dirty input with considerably less manual work.
  - Remesh Tessellated Models
    Use the Remesh to create new surface mesh on converted geometry.
  - Smooth Mesh
    Use the Smooth tool to optimize the mesh quality of parts or surfaces.
  - Refine Mesh
    Use the Refine tool to split elements and optimize the mesh quality of parts and surfaces.
  - Decimate Mesh
    Use the Decimate tool to coarsen mesh based on a defined element size.
  - Create Derived Regions
    Use the Derived Region tool to create enclosed and offset regions around a selection – which can be used to define volumetric refinement levels – or create projected regions in a given direction.
  - Convert Elements and Update FE Geometry
    Convert elements that aren't associated with geometry into FE geometry, or update existing FE geometry.
  - Organize Entities
    Use the Organize tool to move or copy entities into their proper destinations.
  - Repair Surface Mesh
    Use the Repair tool to find, review, and fix issues in the mesh.
  - Automatically Fix Mesh Quality
    The Auto Fix tool is useful for cleaning up non-manifold edges, free edges, intersections, high aspect ratio elements, and proximity distance.
  - Edit 2D Surface Mesh Elements
    Use the Edit tools to manually improve the quality of surface mesh elements and nodes.
  - Fix Normals
    Use the Normals tool to fix element normals using different methods.
- Model Build and Assembly
  Create, organize and manage parts and subsystems.
Meshing
Generate surface/volume mesh by defining mesh controls, or interactively create and edit 2D surface mesh.
Setup
Prepare your model and run the simulation.
Post-Processing
Post-process the simulation results by creating visualizations and measurements.
Design Exploration
Once the baseline model is prepared, you can define morph volumes, morph geometry, create design shapes and run DOE studies. These tool work for both AcuSolve and ultraFluidX-based workflows.
Automation
Automate simulation processes with templates and utility scripts.
Solver Help
More resources for AcuSolve and ultraFluidX solvers.

View All Altair HyperWorks Help

Create Derived Regions

Use the Derived Region tool to create enclosed and offset regions around a selection – which can be used to define volumetric refinement levels – or create projected regions in a given direction.

From the Discrete ribbon, click the Derived Region tool.

Figure 1.
Select entities to consider.

Note: For this tool to work, your selection should have triangular elements.

Click

on the guide bar, select a region type, then define any options.

Enclosed

Creates an enclosed region around the selection with specified offset distance.

Enclosure type

Create enclosures outward or inward from your selection.

Offset distance

Distance of enclosure from selection.

Voxel size factor

Voxel size when creating enclosed region is calculated from the Voxel size factor (Voxel size = Voxel size factor * Offset distance).

Voxel size should be smaller than offset distance. In most cases it is not required to modify this value.

Part name

The enclosure is created in a specified new part.

Note: To use this utility to create a volumetric refinement region for ultraFluidX, follow these steps:

Use the Enclosed option to create enclosed regions with the desired offset distance.
Use the Move tool (by moving nodes) to adjust the shape to cover the wake region and ground.
Use the Smooth tool to smooth the shape.
To create the next refinement level zone, select the above refinement region and use the Directional Offset option with a specified offset distance.

Figure 2. Input

Figure 3. Output with Offset distancce as 75

Directional Offset

Creates an offset region around the selection with specified offset distance.

Direction: Direction along which offset is performed.
Offset distance: Distance of offset region from selection.
Part name: The offset region is created in a specified new part.

Projected

Creates a projected region on a defined plane.

Direction: Normal vector to the required plane.
Part name: The projected parts are created in a specified new part.

Click Create.

Figure 4. Input

Figure 5. Output with Offset distance as 75