Beginning in release 2021 R1, Ansys Forte provides a capability to allow pressure loads from the fluid simulation to interact with boundaries causing them to translate or deform.
Built-in Fluid Structure Interaction (FSI) does not model the response of the solid parts with first principles. For the two supported models, rigid body translation/rotation, and cantilever deformation, assumptions were made to offer simplified solutions. These assumptions may be good enough to model the applications of interest in some cases, when in reality the load distribution could be more complicated.
As built-in FSI does not require another software, it may be less complicated from a user's point-of-view and incur less computational cost in comparison to 2-way FSI using Ansys Mechanical and System Coupling. However, since Mechanical can do transient structural analysis, it may give more accurate results in calculating the response from any given load distribution.
The capabilities of Built-in FSI are:
Rigid body translation/rotation based on spring mass system with damping
Cantilever deformation according to Euler's beam equations for 3 loading scenarios
User-defined motion based on one or more surface field values
To enable Built-in FSI in Forte, enable the component in the Workflow tree under Simulation Controls. Then add one or more FSI components available from the toolbar, such as springs and beams.
Note: If the simulation setup includes a Gap Refinement (in Mesh Controls for Automatic Meshing) with the Block Flow Across Gap option enabled (recommended for gaps associated with a built-in FSI), the blockage will be applied only when the moving body of the FSI is inactive, that is, when its displacement is below the activation threshold. Note that this flow blockage option cannot completely block the flow. It can only mitigate the leakage through the gap as much as possible.