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 The information provided may be out of date.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.

3D or 2D, which model I should use?

Please login with a confirmed email address before reporting spam

Dear helper,

I am confused of a very simple (should be) problem: when should one use a 2D simulation to replace so simplify 3D simulation?

Theoretically, this should happen when the size along one dimension is infinite so its effect can be neglected. I wonder if the geometry in consideration is symmetric, i.e. a rectangular block with large width and length but much smaller thickness(100 smaller than the width and length, width equals to the length), can I take it as a 2D problem?

I am studying a heat transfer problem inside a device with huge substrate and thin film semiconductor layer.

Thank you very much.

2 Replies Last Post 11 gen 2011, 11:39 GMT-5
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 11 gen 2011, 11:25 GMT-5
Hi

in general a 2D model always solves quickerthan a 3D, and requires far less RAM. ut there are many reasons and arguments how & why to choose a 2D rather thana 3D model. I would say to make it short, if the physics in 1 direction is not seeing ny major changes, you can says your model is expressed "per meter depth" then a 2D model should be better. The same if you have axi-symmetric geoemtry AND boundary conditions, then a 2D axi is easier than a full 3D. Unfortunately, you need correct symmetry in the geoemtry AND simulatneously for the boundary conditions

--
Good luck
Ivar
Hi in general a 2D model always solves quickerthan a 3D, and requires far less RAM. ut there are many reasons and arguments how & why to choose a 2D rather thana 3D model. I would say to make it short, if the physics in 1 direction is not seeing ny major changes, you can says your model is expressed "per meter depth" then a 2D model should be better. The same if you have axi-symmetric geoemtry AND boundary conditions, then a 2D axi is easier than a full 3D. Unfortunately, you need correct symmetry in the geoemtry AND simulatneously for the boundary conditions -- Good luck Ivar

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 11 gen 2011, 11:39 GMT-5
Thank you very much for the quick reply.

I just compared the 2D results with 3D. The 3D simulation is so, so slow. Good thing is the two results are very similar and I think it is reasonable to do the 2D simulation.
Thank you very much for the quick reply. I just compared the 2D results with 3D. The 3D simulation is so, so slow. Good thing is the two results are very similar and I think it is reasonable to do the 2D simulation.

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.