Note: This discussion is about an older version of the COMSOL Multiphysics® software. The information provided may be out of date.
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.
Meshing with different elements and Order of the discretisation
Posted 12 juil. 2018, 13:34 UTC−4 Structural & Acoustics, Computational Fluid Dynamics (CFD), Mesh Version 4.3b 0 Replies
Please login with a confirmed email address before reporting spam
Hello!
It's like I am solving transport-diffusion model for a 2D domain. I have made the following observations which I cannot figure out. 1.) If I use only triangular mesh without any boundary layers. Then I get double derivative say cxx equal to absolute zero everywhere which is weird. It's like it's not even calculating the derivative. So, if that's true how it can solve the Laplacian term in the model. 2.) If I use triangular plus boundary layer. Then cxx is evaluated only at the boundary layer. Rest domain is absolute zero. And I have set relative tolerance 1e-6. So my solution is converged. But inspite of this fact I am not getting cxx+cyy=0 or close to 0. Why? I am unable to explain. 3.) If I use triangles plus second-order discretization. Now I am able to get cxx all over the domain. Why? 4.) Lastly, if I use quads as my meshing elements I can define cxx at every point. However, cxx+cyy is not close to zero everywhere. It would be great if someone could help me to figure out these observations.
Best Regards, Ayush
Hello Ayush Upadhyay
Your Discussion has gone 30 days without a reply. If you still need help with COMSOL and have an on-subscription license, please visit our Support Center for help.
If you do not hold an on-subscription license, you may find an answer in another Discussion or in the Knowledge Base.