DFBI Morphing: Boundary Settings Reference

For the DFBI morphing motion, you set morphing conditions at the boundaries. The same boundary conditions as for the morphing motion are available. In addition to these standard morphing boundary conditions, you can set specific DFBI morphing boundary conditions.

For an overview of the standard morpher boundary conditions, see Morpher Boundary Condition.
Six DOF Morpher Specification
Specifies the method that the morpher uses to morph the boundary. In addition to the standard morphing methods, there is also one DFBI specific method—Six Dof Body:
Method Corresponding Physics Condition Nodes Corresponding Physics Value Nodes
Six Dof Body
Vertices on this boundary move according to the motion of a 6-DOF body with or without an additional specified displacement is superposed. During initialization, this morphing condition is set automatically for boundaries that are selected as Body Surface of the 6-DOF body (see 6-DOF Body (Rigid Body)).

Can also be used for boundaries that do not define a 6-DOF body. In such cases, this morphing method is not applied automatically and must be set explicitly.

Can also be used:
  • at interface boundaries that connect, for example, a DFBI morphing region with a DFBI rigid body motion region. Vertices on the interface boundary of the DFBI morphing region move according to the vertex motion at the interface boundary of the DFBI rigid body motion region.
  • at interface boundaries that are in contact with a deformable solid region (that is, a solid region that is modeled using the Solid Stress model). Vertices on the interface boundary of the DFBI morphing region move according to the 6-DOF rigid motion and the additional motion imparted by the contacting solid, also accounting for the solid deformation. For details, see Modeling Fluid-Structure Interaction (FSI).
Displacement Projection
Allows you to project the 6-DOF body displacement onto a specified direction.
  • Deactivated

    Default option. No projection is applied.

  • Activated

    Projects the displacement of the 6-DOF body onto a direction that you provide. The vertices on this boundary are only allowed to move in the specified direction. Increases the flexibility of the 6-DOF Body option in that only specified parts of the 6-DOF body displacement are allowed to move. Here you set up Displacement Projection which specifies the direction of projection with respect to a coordinate system.

Deformation Specification
Allows an extra deformation on top of DFBI body motion. Available when you set Six DOF Morpher Specification to Six Dof Body.

The available options are:

  • None—no additional deformation is defined to the DFBI motion.
  • User-Defined—allows an additional deformation on top of DFBI motion. The morpher activates the following two Morpher Displacement Specification:
    • Total
    • Incremental
In case of a Solid Stress application, at interface boundaries that are in contact with a deformable solid region, you choose whether the deformation of the contacting solid is accounted on top of the DFBI motion. The available options are:
  • None—the morpher does not account for the solid deformation.
  • Solid Stress—when morphing the fluid boundary, the morpher also accounts for the deformation of the contacting solid boundary.
The typical scenario is the simulation of a ship propeller. In this case, you can model the ship body as a 6-DOF rigid body, and the propeller as a deformable solid with prescribed rotation. The surrounding fluid mesh moves according to the rigid motions and can account for the non-rigid deformations calculated by the solid stress solver.
For the contacting solid region, the following requirements apply:
  • The physics continuum associated with the solid region uses the Solid Stress model. See Selecting Solid Stress Physics Models.
  • The motion of the solid region follows the 6-DOF motion, with an additional superposed rigid motion and the Solid Displacement motion, which accounts for the solid deformation due to the forces imparted by the surrounding fluid. For example, [6-DOF Body Motion] > Rotation > Solid Displacement.
For more information, see Modeling Fluid-Structure Interaction (FSI).
Morpher Rigid Boundary Motion
Allows you to combine the incremental linear displacement morphing motion of this boundary with a rigid motion. You can select rigid motions that are superposed to the 6-DOF rigid body motion.
Morpher Total Linear Displacement
When Total is selected as user-defined Morpher Displacement Specification.
Morpher Incremental Linear Displacement
When Incremental is selected as user-defined Morpher Displacement Specification.