Menu

Discussion Forum

New Discussion
Filter

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 to define the boundary conditions for oscillatory flow in COMSOL?

Posted Mar 7, 2017, 6:42 p.m. EST Fluid & Heat, Acoustics & Vibrations, Heat Transfer & Phase Change, Computational Fluid Dynamics (CFD), Studies & Solvers 2 Replies

Muyassar Ismaeel
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Hi

I want to model an oscillatory flow passing fins inside a resonator.

I need to define both of the velocity and pressure boundary conditions at the inlet (x1) and the outlet (x2) of the computational domain.

The boundary conditions are given as:
p1 (x,t)= po cos (k' x1 ) cos⁡(ωt)

ua1= po/(ρm c) sin⁡(k' x1 )

p2 (x,t)= po cos⁡ (k' x2 ) cos⁡(ωt)

ua2= po/(ρm c) sin⁡(k' x2 )

∂T/∂x = 0 at x1 and x2

Could anybody assist me, please?

Thanks
Muyassar
2 Replies Last Post Apr 11, 2017, 3:41 p.m. EDT
COMSOL Moderator

Hello Muyassar Ismaeel

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.

Reza Ansari Shirvan
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 7 years ago Apr 11, 2017, 8:24 a.m. EDT
Hi Muyassar,

Define a waveform function first to form the sinusoidal part of the boundaries and then multiply it to the constant part of your boundary condition.

You can find the waveform function by right clicking on Definitions (under Component 1).
Then apply phase, amplitude and Angular frequency (to create proper sin/cos functions that you want)

Take a look at here:
www.comsol.dk/community/forums/cfd/thread/139992/

Best regards,
Reza

Hi Muyassar, Define a waveform function first to form the sinusoidal part of the boundaries and then multiply it to the constant part of your boundary condition. You can find the waveform function by right clicking on Definitions (under Component 1). Then apply phase, amplitude and Angular frequency (to create proper sin/cos functions that you want) Take a look at here: https://www.comsol.dk/community/forums/cfd/thread/139992/ Best regards, Reza
Muyassar Ismaeel
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 7 years ago Apr 11, 2017, 3:41 p.m. EDT
Hi Reza

Thank you very much.
I will try your suggestions..

regards
Muyassar
Hi Reza Thank you very much. I will try your suggestions.. regards Muyassar

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