Fluid-Structure Interaction

Fluid-structure interaction (FSI) is the multiphysics study of how fluids and structures interact. The fluid flow may exert pressure and/or thermal loads on the structure. These loads may cause structural deformation significant enough to change the fluid flow itself. Undesired effects in your product may increase as the level of the fluid-structure interaction increases. With ANSYS simulation you can gain a deeper understanding of the phenomena occurring with your product to ensure safety, reliability and longevity.

ANSYS has a range of solutions for all the fluid-structure interaction challenges one may face to provide the level of fidelity needed. Simple fluid-structure interaction problems can be solved completely within ANSYS CFD. This is known as rigid body motion, exemplified by an impeller rotating in a mixing tank.

As the fluid-structure interaction increases and the problem needs more detailed evaluation, ANSYS has an automated, easy-to use-solution called one-way coupling. One-way coupling solves the initial CFD or ANSYS Mechanical simulation and automatically transfers and maps the data to the other system. An example of this would be simulating the fluid flow around a cone flow meter and automatically transferring this data to calculate the resulting structural response.

For the most complex and tightly coupled fluid-structure interaction problems, you can use System Coupling to perform two-way coupled FSI simulations. The fluid and structural simulations are both set up and solved at the same time. While being solved, data is automatically transferred between the two solvers to achieve robust and accurate results. An example of this would be calculating flow around a rigid airplane wing and transferring the pressure loads to solve structural deformation. The structural deformation would be transferred back to the CFD simulation to calculate the flow again, and this process would repeat.

Accurately assess wing performance by calculating flow around the wing and transferring the pressure loads to solve structural and mesh deformation by coupling ANSYS CFD and Mechanical.


Coupling of ANSYS CFD and Mechanical can quickly and accurately predict a blade flutter analysis to ensure the mechanical vibration will be damped out at natural frequencies by the aerodynamic loads.

Simulating the two-phase flow of liquid and air to accurately predict container wall deformation by coupling ANSYS CFD and Mechanical. Courtesy Tetra Pak