Learning Forum

[as4934]

I am trying to simulate Fluid Structure Interactions on ANSYS with fluent, transient structural and system coupling. My model is set to simulate flutter - a bar of aluminum passing through multiple sections of airfoils (to induce flexibility) and a weight at the top to add inertia. Everything is good until I update the solution in the system coupling module. I am having issues with convergence and would appreciate any feedback on my setup (it diverges at the first time step - 0.1 second). I have dropped the time step to 1e-08 and I still have the same error. Any help will be greatly appreciated.

[Rahul]

Hello 

Ensure that your participant solution solved alone works well before coupling.

If the coupled run fails:
‐ Find out which solver failed first – look at all the output files to determine where the error started
‐ Check the mapping
‐ If MAPDL, were reasonable forces / thermal loads received?
‐ If Fluent, were reasonable displacements / thermal loads received?
‐ Were the individual field solvers converging?
‐ If a run fails in the first few time steps, re-run for a limited number of time steps and/or with a limited 
number of Coupling Iterations so that you can generate results files and examine the result

Also, refer to: Building a Coupled FSI Analysis from Decoupled Participant Problems (ansys.com)

Improving the Accuracy of Transient Analyses (ansys.com)

Improving Coupled Analysis Stability (ansys.com)