Home
Pre-Processing
Simcenter STAR-CCM+ solves physics problems on a computational mesh. To provide this mesh, you first define geometry using internal or external tools, and then create a mesh pipeline whose operations generate the mesh in repeatable steps.
3D-CAD
3D-CAD is a feature-based parametric modeler within Simcenter STAR-CCM+ that allows you to build geometries from scratch. The geometries that you create with 3D-CAD are stored as 3D-CAD models, which you can then convert to geometry parts for integration with the meshing and simulation process.
Geometry Repair and Preparation
Simcenter STAR-CCM+ provides a suite of tools in 3D-CAD that helps you to prepare your CAD geometry so that it is suitable for meshing. CAD that is designed for manufacture can have gaps or inaccuracies that cause problems when trying to generate a watertight mesh.
Working with Volume Extraction
3D-CAD can automatically extract the volume of space surrounding a model or volume of space inside a model, and use it to form a new, separate solid body.
Internal Volume Extraction
In internal volume extraction, 3D-CAD caps holes in the model geometry, and fills the void inside the model with a new solid body.

Share

Link: copied

Breadcrumb: copied

Pre-Processing
Simcenter STAR-CCM+ solves physics problems on a computational mesh. To provide this mesh, you first define geometry using internal or external tools, and then create a mesh pipeline whose operations generate the mesh in repeatable steps.
- 3D-CAD
  3D-CAD is a feature-based parametric modeler within Simcenter STAR-CCM+ that allows you to build geometries from scratch. The geometries that you create with 3D-CAD are stored as 3D-CAD models, which you can then convert to geometry parts for integration with the meshing and simulation process.
  - 3D-CAD Environment
    The 3D-CAD environment provides you with a feature tree from which you can activate all steps for creating and modifying geometry, and a 3D-CAD View scene in which you interact with the geometry. Many of the same feature actions are available for selection in the 3D-CAD View scene.
  - Sketches in 3D-CAD
    3D-CAD supports two types of sketch—2D sketches that are created on a planar surface and 3D sketches that are built from points located anywhere in geometric space. You can use both types of sketch in 3D geometry operations such as extrude, revolve, or sweep.
  - 3D-CAD Geometry Modeling
    Bodies represent the individual objects that make up the 3D-CAD model. Imported CAD geometry appears as bodies in 3D-CAD, and you can also create your own bodies directly using 3D-CAD features.
  - Freeform Surface Modeling
    Freeform surface modeling is a modeling technique in 3D-CAD that allows you to deform existing surfaces for desired shapes.
  - Importing and Exporting Geometry
  - Working with 3D-CAD Models
  - Geometry Repair and Preparation
    Simcenter STAR-CCM+ provides a suite of tools in 3D-CAD that helps you to prepare your CAD geometry so that it is suitable for meshing. CAD that is designed for manufacture can have gaps or inaccuracies that cause problems when trying to generate a watertight mesh.
    - Repairing CAD Geometry
      The Repair CAD tool provides diagnostic checks for assessing the validity of bodies and attempts to repair them automatically. You can typically use this tool first in order to assess the extent and location of problems, and then use specific repair tools to resolve them.
    - Search Tool
      The Search Tool is a feature in 3D-CAD that helps you to find and organize geometric entities, (that is, body groups, bodies, faces, edges, or vertices) using search criteria based on geometry, features, or similarities. The tool can also search for entities that clash or are in close proximity.
    - Working with Repair Tools
      The repair tools option simplifies the way you access features to repair a geometry in Simcenter STAR-CCM+.
    - Removing Unwanted Features
      The defeature function in 3D-CAD allows you to remove unwanted features from a geometry. Unwanted features can include faces, holes, protrusions, chamfers, and fillets. The defeature function can also merge split surfaces into a single surface.
    - Working with Volume Extraction
      3D-CAD can automatically extract the volume of space surrounding a model or volume of space inside a model, and use it to form a new, separate solid body.
      - What Is Volume Extraction?
        When you extract a volume, 3D-CAD finds a continuous surface within, or around, a solid model and uses it to create a new body.
      - Internal Volume Extraction
        In internal volume extraction, 3D-CAD caps holes in the model geometry, and fills the void inside the model with a new solid body.
        Extracting the Internal Volume
        Internal volume extraction helps create an enclosed geometry that represents a fluid domain and also detect leaks when the initial extraction fails.
        Internal Volume Extraction Panel
        Use the following properties to define the internal volume extraction.
      - External Volume Extraction
        External aerodynamics simulations require a fluid domain surrounding the object of interest. You can create this fluid domain as a solid body in 3D-CAD and extract the required external volume, leaving a cavity of the geometry that you want to analyze.
  - Design Parameters
    Design parameters allow Simcenter STAR-CCM+ to update geometry designs during design exploration studies. Although you define them within the 3D-CAD environment, they are exposed outside 3D-CAD for manual or automatic update.
- Modeling Geometry
  This part of the User Guide describes how to use 3D-CAD, the parametric solid modeler available within Simcenter STAR-CCM+. It also describes the features and tools available for further preparation of the geometry model and its surfaces.
- The Surface Repair Tool
  The Surface Repair tool diagnoses errors in, and provides repair tools for, tessellated surfaces and part curves. The same tool allows you to reorganize discretized geometry by searching for face-based features and attributes then assigning the results to new or existing part surfaces or curves.
- Defining the Regions Layout
  An essential part of the process in setting up your simulation is to define the relationship between geometry parts and regions, boundaries, and interfaces.
- Meshing
  A mesh is a discretized representation of a geometric domain. This domain can include real-world geometry, its content, and its surrounding environment.

Internal Volume Extraction

In internal volume extraction, 3D-CAD caps holes in the model geometry, and fills the void inside the model with a new solid body.

The holes are often entry and exit points for a fluid, such as the start and end of a pipe. You identify these openings by selecting faces and/or edges. When you select a face, 3D-CAD analyzes it for the presence of any holes. Selecting edges specifies the exact location of a hole. If a solid body can be created by capping some or all of the holes that are found, the extraction process is successful. The extraction process fails if material can leak out of the model through any other holes. In such cases, you can identify locations through which material escapes using the leak detection tool.

The internal volume can span multiple bodies. During the operation, all bodies are united. When you create a solid body using internal volume extraction, an imprint operation is carried out automatically so that the edges of the new body are imprinted on existing bodies, and vice versa. The internal volume extraction tool recognizes any bodies that intersect or are located within the internal volume, and molds the new solid body around them. If these bodies do not contribute to the flow, you can choose to exclude them from the extraction.

Requirements

The 3D-CAD model must meet the following criteria in order to carry out internal volume extraction:

The edge loop of each hole must lie on a single face, or cross a maximum of two connected faces. If the loop crosses three or more faces, 3D-CAD does not recognize the hole.
The edges of each hole must lie on the same plane. Objects inside a hole are allowed and can extend beyond the hole opening.
The faces or edges that define the holes in the model are selected manually, and there can be any number of holes in the geometry.
If the internal volume spans multiple bodies, these bodies must be able to unite successfully.
Annular regions are supported.