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 The information provided may be out of date.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.

How do materials properties are considered in k-epsilon turbulent model?

Please login with a confirmed email address before reporting spam

Hi everyone,

I have a doubt about how material properties are considered in k-epsilon turbulent models. I'm simulating air flow around buildings and I specified materials for the ground and the buildings facades (concrete). I've realized that the wind speed on the top of a building in the middle of a very dense region of interest is exactly the same as the velocity measured in the same height from the ground in the meteorological station. I have three questions:

1 - If surface roughness may reduce air velocity, how does it doesn't change in the middle of the region of interest? Even if it the measure point is on the top of buildings, shouldn't the top surfaces of buildings influence on velocity air flow?

2 - I didn't find in the turbulent model equation any variable related to materials properties. So how does COMSOL consider their influence on air flow?

3 - I read a discussion in this forum about the parameter B of turbulent model (www.comsol.com/community/forums/general/thread/33544) and I was wondering if I should change this to represent the roughness height of this urban context.

Thank you very much for your help.

Marilia


0 Replies Last Post 06.05.2013, 11:30 GMT-4
COMSOL Moderator

Hello Marilia Fontenelle

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.

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.