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.
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.
Region Reposition
The Reposition Model adds a transformation to the volume mesh representation of a region at the point of simulation initialization. That is, the transformation applies in the case of a new simulation or a simulation with cleared solution. In some automated simulation or design exploration studies, your objective is to obtain results for a series of simulations in which the relative positioning of one part changes in each simulation. An example is an airfoil with a changing angle of attack. Using the Reposition Model, you can wrap the geometry that changes in an overset region, and then use the Reposition Specification on the region to define the orientation at the start of each new simulation run.
Reposition Model Reference
Reposition model transforms the volume mesh representation of a region. The reposition action is only triggered during a new solution initialization. This behavior means that you must either be starting the first run of a new simulation or else you must clear the old solution.

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.
- 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.
  - Regions Layout Workflow
    In defining the regions layout you map between the geometrical definition of the problem and the computational (or physical) definition.
  - Assigning Parts to Regions
    Before a leaf-level part can be used in the meshing process, it must be assigned to a region.
  - Assigning Part Surfaces to Boundaries
    As with parts and regions, a bi-directional relationship exists between part surfaces and boundaries.
  - Using the Assign Parts to Regions Dialog
    The Assign Parts to Regions dialog lets you assign several part-level objects to region-level objects in one action. This dialog is the recommended method of assigning parts to regions.
  - Initial Assignment of Boundary Types
  - Interfaces Overview
    Interfaces are used in Simcenter STAR-CCM+ to transfer solution quantities between regions in a simulation. Certain types of interfaces modify quantities passing across them, such as a porous baffle interface that presents resistance to fluid flow. Periodic and repeating interfaces allow you to reduce the scope of the solution domain.
  - Region Manipulation
    To fix surface or volume meshes that are not suitable for obtaining a valid solution, choose from among various techniques for manipulating regions.
  - Region Reposition
    The Reposition Model adds a transformation to the volume mesh representation of a region at the point of simulation initialization. That is, the transformation applies in the case of a new simulation or a simulation with cleared solution. In some automated simulation or design exploration studies, your objective is to obtain results for a series of simulations in which the relative positioning of one part changes in each simulation. An example is an airfoil with a changing angle of attack. Using the Reposition Model, you can wrap the geometry that changes in an overset region, and then use the Reposition Specification on the region to define the orientation at the start of each new simulation run.
    - Reposition Model Reference
      Reposition model transforms the volume mesh representation of a region. The reposition action is only triggered during a new solution initialization. This behavior means that you must either be starting the first run of a new simulation or else you must clear the old solution.
  - Manipulating Boundaries
    It is often convenient to modify boundaries in the simulation without having to modify the mesh and re-import it.
  - Performing Boolean Operations on Regions
    Boolean operations can be performed between two or more intersecting, closed, manifold regions to create a single region made up of a single surface. The new surface is also closed and manifold and can be used as part of the meshing process or as the starting point for additional Boolean operations.
- Meshing
  A mesh is a discretized representation of a geometric domain. This domain can include real-world geometry, its content, and its surrounding environment.

Reposition Model Reference

Reposition model transforms the volume mesh representation of a region. The reposition action is only triggered during a new solution initialization. This behavior means that you must either be starting the first run of a new simulation or else you must clear the old solution.

Reposition Model


Example Node Path	Continua > Physics 1 > Models > Reposition
Applications	Automated simulations, Design Exploration
Requires	Flow The Reposition model is not compatible with: Fluid Film Model Lagrangian Multiphase Model Harmonic Balance Time Model
Properties	None

[region] Physics Conditions

When you add the Reposition Model in the physics continuum, the following physics condition appears to all the associated regions.

Reposition Option: Activates the Reposition solver for the region. When activated, the Reposition Specification node is added to Physics Values.

[region] Physics Values

Reposition Specification

Specifies rotation and translation inputs for this region.

Rotation Angle: Specifies rotation angle for region reposition with respect to the very initial position of the volume mesh presentation.
Rotation Axis Direction: Specifies the rotation axis direction vector.
Rotation Origin: Specifies the coordinate for the rotation origin.
Translation: Specifies the translation vector for region repositioning.
Coordinate System: Specifies the coordinate system, in which the rotation origin, axis, and translation are defined.
Managed Coordinate System: Adds the coordinate systems which are repositioned together with the region.
The children of a selected coordinate system are also transformed. If both parent and child systems are selected under the node, the child system is then transformed twice.

Reposition Solver Properties

Solver Frozen: When On, the solver does not update any quantity during an iteration. It is Off by default. This is a debugging option that can result in non-recoverable errors and wrong solutions due to missing storage. See Finite Volume Solvers Reference for details.