Menu

Discussion Forum

New Discussion
Filtrer

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.

Potato in microwave oven : problem in pulsing microwave source

Posted 21 janv. 2018, 13:38 UTC−5 2 Replies

Prateek Katare
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Hello!

I was fiddling around with the "potato in microwave" example of microwave heating and noticed that it uses continous microwave heating. Practically, at < 100% power setting, the microwave uses PWM.

So I defined an analytic function to mimic the pulsed microwave source (at 20% duty cycle) and fed it into the "P in" part of the EMW (electromagnetic waves) physics

However, I got the same results as the full-power (100% futy cycle). I even changed the solver to "Strict" but no difference.

I also made another model that uses only "heat transfer" and fed the analytic function to its "heat source" section - this was successful and the heating plots follow the periodicity of the defined function.

So what did I miss here? Why does coupling two physics (EMW and HT) in the potato heating simulation mislead COMSOL into treating a pulsed source as just a continous source?

Thanks in advance !

2 Replies Last Post 19 févr. 2018, 05:04 UTC−5
Sohan Birla
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 7 years ago 26 janv. 2018, 15:31 UTC−5

Prateek, If your material dielctric proeprties are not temperature dependent, the EM solver do not see the need for calcualting EM field for marching time steps.

Prateek, If your material dielctric proeprties are not temperature dependent, the EM solver do not see the need for calcualting EM field for marching time steps.
Prateek Katare
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 7 years ago 19 févr. 2018, 05:04 UTC−5

Thanks Sohan

I eventually tried a frequency-transient study and it worked just fine. Couple of points to be noted though 1) Solver must be "strict" 2) The study needed to be "segregated" else the solution never converged.

So now I have the pulsed EM heating simulation working just fine.

Thanks Sohan I eventually tried a frequency-transient study and it worked just fine. Couple of points to be noted though 1) Solver must be "strict" 2) The study needed to be "segregated" else the solution never converged. So now I have the pulsed EM heating simulation working just fine.

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