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.

Difference between solvers: nearly incompressible compressible etc

Please login with a confirmed email address before reporting spam

Hi

I'm simulating a fluid-solid interaction and the nu = 0.49. I'm using Hyperelastic material for the material's model. I changed the solver from nearly incompressible to compressible and incompressible and I also tried linear elastic material. the Young's modulus is in order of megapascal. I don't see any difference between the material displacement. I looked in different places, but to be honest, I'm not sure what I should look for exactly. Can someone either introduces me a reference to look up what the difference is between each of these solvers and why I'm not getting any different results or if they know, let me know what's going on?

https://www.comsol.com/forum/thread/10958/Poisson-ratiov05 The link says if the nu=0.49, I should try nearly incompressible.

Thank you in advance.


1 Reply Last Post 31.01.2024, 05:18 GMT-5
Henrik Sönnerlind COMSOL Employee

Please login with a confirmed email address before reporting spam

Posted: 10 months ago 31.01.2024, 05:18 GMT-5

At nu=0.49 it should still be safe so the differences will be small. I think that value is mentioned to make sure that you are on the safe side.

If you want to study the effect, use something like 0.4999. What you expect to see then is a checkerboard pattern in the stresses if you don't use a mixed formulation.

-------------------
Henrik Sönnerlind
COMSOL
At nu=0.49 it should still be safe so the differences will be small. I think that value is mentioned to make sure that you are on the safe side. If you want to study the effect, use something like 0.4999. What you expect to see then is a checkerboard pattern in the stresses if you don't use a mixed formulation.

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.