Using CFD Boundary Conditions

Trelis supports the following CFD boundary condition types. All use the same syntax and use the same command panel (shown below) to create and modify the boundary condition.

The GUI Command Panel for creating an Axis boundary condition is shown below.

Trelis can export models to the Fluent mesh format and supports defining the above CFD boundary conditions. Only the region on which the BC acts can be defined in Trelis. The data associated with each boundary condition (pressure, velocity, mass values) is not defined within Trelis and must be assigned using a CFD model editor, such as Fluent.

The following shows the commands for creating and modifying some sample CFD boundary conditions. To delete them, use the delete command (see Miscellaneous Commands).

Inlet Velocity

To create and modify inlet velocity

  1. On the Command Panel, click on CFD BCs.
  2. Click on the Create or Modify action button.
  3. Select Velocity Inlet from the drop-down menu.
  4. Enter the appropriate settings.
  5. Click Apply.

Create Inletvelocity [id] [name <'name'>] [{Add|On} {Surface} <entity_list>]

Modify Inletvelocity [id] [name <'name'>] [{Add|Remove} {Surface} <entity_list>]

Inlet Pressure

To create and modify inlet pressure

  1. On the Command Panel, click on CFD BCs.
  2. Click on the Create or Modify action button.
  3. Select Pressure Inlet from the drop-down menu.
  4. Enter the appropriate settings.
  5. Click Apply.

Create Inletpressure [id] [name <'name'>] [{Add|On} {Surface} <entity_list>]

Modify Inletpressure [id] [name <'name'>] [{Add|Remove} {Surface} <entity_list>]

Inlet Massflow

To create and modify inlet massflow

  1. On the Command Panel, click on CFD BCs.
  2. Click on the Create or Modify action button.
  3. Select Mass Flow Inlet from the drop-down menu.
  4. Enter the appropriate settings.
  5. Click Apply.

Create Inletmassflow [id] [name <'name'>] [{Add|On} {Surface} <entity_list>]

Modify Inletmassflow [id] [name <'name'>] [{Add|Remove} {Surface} <entity_list>]

Outlet Pressure

To create and modify outlet pressure

  1. On the Command Panel, click on CFD BCs.
  2. Click on the Create or Modify action button.
  3. Select Pressure Outlet from the drop-down menu.
  4. Enter the appropriate settings.
  5. Click Apply.

Create Outletpressure [id] [name <'name'>] [{Add|On} {Surface} <entity_list>]

Modify Outletpressure [id] [name <'name'>] [{Add|Remove} {Surface} <entity_list>]

Farfield Pressure

To create and modify farfield pressure

  1. On the Command Panel, click on CFD BCs.
  2. Click on the Create or Modify action button.
  3. Select Pressure Far Field from the drop-down menu.
  4. Enter the appropriate settings.
  5. Click Apply.

Create Farfieldpressure [id] [name <'name'>] [{Add|On} {Surface} <entity_list>]

Modify Farfieldpressure [id] [name <'name'>] [{Add|Remove} {Surface} <entity_list>]

Symmetry

To create and modify symmetry

  1. On the Command Panel, click on CFD BCs.
  2. Click on the Create or Modify action button.
  3. Select Symmetry from the drop-down menu.
  4. Enter the appropriate settings.
  5. Click Apply.

Create Symmetry [id] [name <'name'>] [{Add|On} {Surface} <entity_list>]

Modify Symmetry [id] [name <'name'>] [{Add|Remove} {Surface} <entity_list>]