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 The information provided may be out of date.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.

Problems with 3D turbulent flow

Please login with a confirmed email address before reporting spam

Hi All,

I have been trying to use comsol to study turbulent flow in a 3D domain. The Reynolds number is around 470.000, so we are talking about fully turbulent flow.

I can get under control the wall lift-off distance, both dimensional and dimensionless, and I do obtain a solution.

Unfortunately the solution is quite wrong: there is a large difference between the computed pressure drop and what is actually measured on the test bench. The numerically computed head loss is about 0.12 bar with comsol, the actual pressure drop is about 0.54 bar.

Has anyone experienced similar problems while using the CFD package?

Here is the model:


1 Reply Last Post 20 avr. 2011, 09:08 UTC−4

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 20 avr. 2011, 09:08 UTC−4
So far no good luck.

Has anyone ever tried to get a 3D turbulent flow done?

The only reply I got from support was that I needed to redraw my geometry because it caused the mesh to be too fine on a surface and that prevented Comsol to operate properly.

A too refined mesh may cause problems in resolving the boundary layer and it may create artifacts, but how is it possible that Comsol cannot work if the mesh varies from very fine to fine?

Has anyone any idea?
So far no good luck. Has anyone ever tried to get a 3D turbulent flow done? The only reply I got from support was that I needed to redraw my geometry because it caused the mesh to be too fine on a surface and that prevented Comsol to operate properly. A too refined mesh may cause problems in resolving the boundary layer and it may create artifacts, but how is it possible that Comsol cannot work if the mesh varies from very fine to fine? Has anyone any idea?

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.