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 The information provided may be out of date.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.

Temperature variation in transitional flow

Please login with a confirmed email address before reporting spam

Hej everybody,
i am modelling rarefied gasflow (transitional regime) trough a long tube (vacuum at the end). I would like to include some temperature derivations in the model. I know that the transitional flow interface does not give the correct prandtl number in this case even if I consider the correct viscosity.
I thought some coupling between different transitional flow interfaces and some iterative calculations. As an example this means dividing the tube in two parts. For the first calculation simulate the whole tube with Temperature T1 and then take the second part of the tube for an other transitional flow interface with Temperature T2 and take the middle pressure of the first simulation as inlet dor the second interface. (see attached model) Do I need some additional weak constraints (for the correct velocity) and does this generally work?
And if this works how can I account for the flow comming (backscattered) from the second part of the tube (with T2) to the first part (with T1)?

Thanks
Laura


0 Replies Last Post 2014年2月19日 GMT-5 10:52
COMSOL Moderator

Hello Laura Kuckert

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.