I’m explicitly instructing OpenFOAM to not adapt its time step. I’m attempting to set a solver coupling time step that is equivalent to each solver’s time steps such that sub-cycling won’t be required and I can keep total wall time to a minimum. This may not prove possible.
Yes, I believe this was because I did not set a lower limit on the Calculix time step and it was driving itself to zero? I’m not entirely sure, but something was obviously causing the Calculix solver to diverge and leaving it to crunch hard on its solution.
Yes, I can successfully run OpenFOAM and Calculix while de-coupled.
I’ve yet to try this. I was able to overcome the hanging issue without needing to modify the fluid density. I am certainly stuck in the classic added mass scenario where the application dictates that my fluid and solid densities be almost equivalent.
I haven’t ventured to explicit coupling because I understand that the nature of my application has the best chance at convergence with implicit coupling. The low Re, almost equivalent density nature of the problem means a tight coupling will be required to keep things in check, right? I’ve since switched from Aitken to IQN-ILS. I also switched to a nearest-projection mapping, hoping that may increase my displacement accuracy and improve convergence.
I’ve since changed my coupling configuration around a bit, but have yet to arrive at something that converges in fewer than 100 coupling iterations. Am I going to need to increase the
time-window-size and possibly induce some solver sub-cycling? Any general principles I can follow for this type of an application?
Latest precice-config iteration:
precice-config.xml (3.4 KB)