Reply To: Two-way FSI: It’s impossible to simulate a cantilever discharging pipe in Ansys

[Emmanuel Akor]

 

 

Hi Hossein, I had similar challenges with my FSI simuation for airflow in a tube as well but finally got it to work. Negative cell volume is as a result of over distortion or deformation of the pipe. And yes you’re right, decreasing the time step doesn’t help – it didn’t help my case. There were two things I noted that caused this, the “material property” assigned and “convergence”. Aluminum and Steel works because it is pre-defined by Ansys. Nonetheless, your material property seems fine. Are you sure your solution is converging for the “fluid”, “solid”, and “coupled” iterations? If your solution isn’t converging, it means for the iterations that you have, the solutions are inaccurate and might lead to the errors you are having. Remember that the first few iterations are guesses, and the computation might need a few more to arrive at the correct solution. Since I’ve got this to work on my end, I am willing to discuss this in detail via email or look through your file. Also, what does the deformation for Aluminum and Steel look like? Best