Menu

Discussion Forum

New Discussion
Filter

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 The information provided may be out of date.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.

Diffusion-fluid problem

Posted Nov 13, 2011, 6:08 p.m. EST Fluid & Heat Version 4.0a 0 Replies

Nitesh Nama
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Hi I am solving a problem related to the mixing of two fluids (water and CaCl2). In my model the density of the mixture varies as:
rho= A*C+ B*sqrt(C)+ E*(C)^3.5
where A, B and E are constants (dimensional).

I understand that I can use non integral powers to define B and E. However, the model returns an error "trying to evaluate negative power of zero". I believe the model differentiates the equation for some calculations and since C is zero initially, therefore it returns this error. Please suggest how can I solve this. I can't start my simulations from t=0+ as I don't know the value of C at t=0+.

Many Thanks.
0 Replies Last Post Nov 13, 2011, 6:08 p.m. EST
COMSOL Moderator

Hello Nitesh Nama

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.

Suggested Content