Menu

Discussion Forum

New Discussion
Filtern

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 The information provided may be out of date.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.

flow in an assembled block

Posted 24.06.2011, 15:13 GMT-4 Fluid & Heat, Computational Fluid Dynamics (CFD) Version 4.2 2 Replies

Pooyan Tirandazi
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Hi,

I want to model a fluid duct flow in two adjacent blocks (assembled) of equal dimensions.
Basically, I should be getting the same results between the two ducts assembled together and a single duct flow.
Somebody tried this in 3d a while ago (www.comsol.com/community/forums/general/thread/9329/), but I would like to do this in 2d.

As can be seen in the attached file, the results seem to be fine.
The problem is I can only see the flow results for the bottom half of the duct.
How can I see the flow results for the top half of the duct as well?

Any help would be appreciated.

TJ
2 Replies Last Post 27.06.2011, 08:43 GMT-4
Ruud Borger COMSOL Employee

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 25.06.2011, 05:40 GMT-4
Dear Tae Jin,

Thank you for including the model file! In this case, your two quantities of interest are called:

spf.U - flow in the bottom domain
spf2.U - flow in the top domain

What you want is a single variable that includes both of them. This can implemented in the following way:
Go to Model 1 => Definitions, and add "Variables". Select the variables to be valid in Domain 1. Give the variable some name, I choose "Velo", and set it equal to spf.U. Now make a second set of Variables, and assign them to be valid in Domain 2. Again, make "Velo" and here set it equal to spf2.U.

You are almost done now, you only need to update the solution by right-cliking Study 1=> Update solution.

Now, make a Surface plot of "Velo". Nice!

I attached the model file demonstrating this.

Best regards,

Ruud Börger,
COMSOL BV

p.s. In general, I would recommend using "Form union" instead of "Form assembly"... but in this case, don't change a winning team.

Dear Tae Jin, Thank you for including the model file! In this case, your two quantities of interest are called: spf.U - flow in the bottom domain spf2.U - flow in the top domain What you want is a single variable that includes both of them. This can implemented in the following way: Go to Model 1 => Definitions, and add "Variables". Select the variables to be valid in Domain 1. Give the variable some name, I choose "Velo", and set it equal to spf.U. Now make a second set of Variables, and assign them to be valid in Domain 2. Again, make "Velo" and here set it equal to spf2.U. You are almost done now, you only need to update the solution by right-cliking Study 1=> Update solution. Now, make a Surface plot of "Velo". Nice! I attached the model file demonstrating this. Best regards, Ruud Börger, COMSOL BV p.s. In general, I would recommend using "Form union" instead of "Form assembly"... but in this case, don't change a winning team.
Pooyan Tirandazi
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 27.06.2011, 08:43 GMT-4
Hello Ruud,

I thought I was missing something, but didn't think that the two velocities needed the same expression.

Thanks for the help!

TJ
Hello Ruud, I thought I was missing something, but didn't think that the two velocities needed the same expression. Thanks for the help! TJ

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