Menu

Discussion Forum

New Discussion
Filtrer

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 The information provided may be out of date.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.

Time-dependent heat flux [Neumann boundary condition]

Posted 5 nov. 2019, 06:52 UTC−5 Heat Transfer & Phase Change Version 4.3 2 Replies

Denis Kochan
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Hi guys,

I am new in COMSOL, and the same question I am posting, had already circulated several times. Unfortunately, I am not able to solve my problem with the "help" of those posted answers.

  1. I would like to solve time-dependent heat transfer problem in 2d
  2. On some boundaries there (see figure) are prescribed time-dependent incoming heat fluxes, in the form of goniometric functions: , where and are parameters I would like to vary later.
  3. In the module heat transfer in solids, I took "heat flux", out of three possibilities there, I don't know which I should chose, and how to implement my heat flux boundary conditions, say for is 1000 W/m and 20 Hz.

Attachments:

2 Replies Last Post 5 nov. 2019, 08:59 UTC−5
Edgar J. Kaiser Certified Consultant
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 5 years ago 5 nov. 2019, 07:40 UTC−5
Updated: 5 years ago 5 nov. 2019, 08:14 UTC−5

Denis,

if I understand properly this should be quite simple. The expression in the q0 field would look like: q0*cos(omega*t)^2

Define q0 and omega as global parameters or directly insert the values. Make sure that the time stepping properly resolves the function.

Cheers Edgar

-------------------
Edgar J. Kaiser
emPhys Physical Technology
www.emphys.com
Denis, if I understand properly this should be quite simple. The expression in the q0 field would look like: q0\*cos(omega\*t)^2 Define q0 and omega as global parameters or directly insert the values. Make sure that the time stepping properly resolves the function. Cheers Edgar
Denis Kochan
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 5 years ago 5 nov. 2019, 08:59 UTC−5
Updated: 5 years ago 5 nov. 2019, 09:00 UTC−5

Thanks Edgar, it works now ... :)

Cheers,

D.

PS: the time step was inappropriate

Thanks Edgar, it works now ... :) Cheers, D. PS: the time step was inappropriate

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