Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.
Constraints problem in FSI
Posted Jun 16, 2021, 11:28 a.m. EDT Computational Fluid Dynamics (CFD) Version 5.1 1 Reply
Please login with a confirmed email address before reporting spam
hello! i am trying to simulate a fluid-structure interaction model, and when i click solve its giving me an error "Constraints found for variables in different segregated groups. try to merge these groups" what does that mean and how do i merge those groups?
Please login with a confirmed email address before reporting spam
This error means that you are using a Segregated Solver, which in many FSI problems is the default solver. The structural degrees of freedom are most likely in one segregated group, the fluid degrees of freedom in another, and the fluid mesh displacements in a third one. However, you have some constraints that involves two of these three types of degrees of freedom in a single equation. The easiest way round this problem in my opinion is not to merge these groups but to use a Fully Coupled Solver instead of a segregated one. Be careful though that the fully coupled solver requires more memory.
I hope this helps. Nagi Elabbasi