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 The information provided may be out of date.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 2019年11月5日 GMT-5 06:52 Heat Transfer & Phase Change Version 4.3 2 Replies
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.
- I would like to solve time-dependent heat transfer problem in 2d
- 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. - 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:
Please login with a confirmed email address before reporting spam
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
Please login with a confirmed email address before reporting spam
Thanks Edgar, it works now ... :)
Cheers,
D.
PS: the time step was inappropriate