The BC/VC editor allows you to set the problem type as well as Boundary and Volume conditions name and type. It also allows you to perform picking and blanking operations on specific sets of interfaces. It is very convenient to set the BC/VC types and names in CFD-GEOM for two reasons: 1) it is easier to manipulate and identify BC/VC in CFD-GEOM; 2) if you delete/add geometrical entities in the GGD file, only those entities need to be set again, whereas all BC/VC types and names will have to be reset if it was done in CFD-ACE-GUI only.

There are four tools on the BC/VC tab (shown in figure 1): Problem Type, Boundary Conditions Specification, Volume Conditions Specification, and BC/VC Queries.

Figure 1.  BC/VC tab in CFD-GEOM

Below are the description of the first three of these tools. For information on the BC/VC Queries tool, please refer to this tip.

The Problem Type allows for specification of the target solver and the dimensionality of the problem.

• The Problem Dimension option allows you to specify the dimension of the current model: 2D or 3D. This option controls the entity types that are available for picking in the BC and VC specification tools. By default, CFD-GEOM will set this option depending on the types of entities that have been created in the current model, e.g. 3D structured domains, unstructured domains.
• The Target Solver option allows you to specify CFD-ACE+ or CFD-FASTRAN, since these solvers have different boundary condition options available. CFD-ACE+ is the default option for the target solver.

The Boundary Condition (BC) editor allows you to specify a name and type for each boundary in the model. For 3D models, faces and surfaces are available for picking. For 2D models, edges, lines and curves that are part of a surface or a 2D structured domain are available for picking.

To specify a Boundary Condition:

1. Select one or more entities from the graphics area or the entity list
2. Type the new name in the Name input field, and select the type from the Type drop-down list
3. Click Apply to apply the specified name and type while retaining the entities selected
4. Click OK to apply the specified name and type while deselecting the entities
5. Click Cancel to deselect the entities

Figure 2.  Boundary Condition tool with new names and boundary types specified for three entities

There are four columns in the BC editor: Name, Type, Group, and Key. The entity list may be sorted by each of these categories. The columns shown may also be modified by right clicking anywhere in the entity list and selecting/deselecting the columns that should be visible, as shown in figure 3.

Figure 3.  Visible column options for the Boundary Condition editor

The Volume Condition (VC) editor may be used to specify volume names and types (Fluid, Solid, or Block). The layout and use of the VC editor is exactly the same as the BC editor, except that the VC editor works with different entity types (e.g. structured domains, unstructured domains, etc.).

If you have any questions about this tip or would like us to discuss other topics in the future, please let us know.

Regards,
Shivakumar GT
ESI CFD Support Team