Define the Computational Domain

• In the Flow Simulation Analysis tree, right-click the Computational Domain item and select Edit Definition.

• On the ribbon, click Tools > Flow Simulation > Project > Computational Domain.

• In the menu, select Tools > Flow Simulation > Computational Domain.

• 3D simulation . You can retain the default 3D flow analysis.

• 2D simulation . If you are fully confident that the flow can be simulated by a 2D flow, you can redefine the computational domain to a 2D analysis resulting in decrease in required memory and CPU time. For the 2D flow analysis the symmetry boundary condition is set on two opposite boundaries of the computational domain having one Basic mesh cell between the boundaries.

  Then select the corresponding flow plane in which you want to simulate a 2D flow: YZ-, or XY-, or XZ-plane.

  Note:

  Since 2D analysis is performed as a 3D analysis with several computational cells in the third direction, it is correct only for solids with plane surfaces perpendicular to a Global Coordinate System plane.

They may include rotation and heat conduction in solids.

Then specify the periodic sector parameters. See “Axial Periodicity” for details.

• Type new computational domain boundary coordinates with respect to the Global Coordinate System in the corresponding boxes (i.e., X max , X min , etc.). See “Resizing the Computational Domain” for details.

• Select an appropriate condition for each boundary plane in the list right to the corresponding boundaries (i.e., X max , X min , etc.):

  • Default  boundary condition dependent on the Internal or the External analysis type.

  • Symmetry  (see “Symmetry Planes”for details).

    If you are fully confident that the internal or external flow contains one or more symmetry planes, you can separate a relevant flow region by resizing the computational domain. The flow symmetry planes can be utilized as computational domain boundaries with specified Symmetry conditions on them. In this case, the computational domain boundaries must coincide with the flow symmetry planes. Since the physical size of the flow problem is reduced, both computer memory requirements and CPU time will be reduced.

    Note:

    Sometimes symmetry of both the model and the incoming (inlet) flow does not guarantee symmetry in other flow regions, e.g. a von Karman vortex street past a cylinder.

  • Periodicity  (see “Periodic Boundary Conditions”for details).

    If you analyze a fluid flow in the model consisting of identical geometrical features arranged in periodic linear order, you can specify the Periodicity condition at the computational domain boundaries in the direction in which identical geometrical features repeat regularly over distance. This allows to reduce the calculation time.

• Click the Reset button to reset the domain size and return to the computational domain generated automatically by Flow Simulation.

• In the Edge Color  list you can select the color for edges of the computational domain frame.

• In the Face Color  list you can select the color for faces of the computational domain frame.

• You can also adjust the transparency of all computational domain faces with the Face Transparency .