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.

Heat transfer problem (varying temperature with time)

Please login with a confirmed email address before reporting spam

Hallo,
I am new in COMSOL and trying to run a simple heat transfer simulation in COMSOL (heat transfer in solid module). I want to simulate a time dependent temperature distribution for a simple geometry what i attached here and want to see the temperature changes over the whole domain. The problem is, i can't find the way to vary the temperature. For example i want the temperature profile like:
time(s) temperature(K)
1 297
2 298
... ....
236 533

So time interval is 1 second and temperature starts from 297 to 533 K.

Can anybody please tell me how can i vary the temperature with time that i can input as boundary condition (temperature node) or any possibility to import a tabular format (time and temperature) that i can use as input.

It would be really helpful for me to have the answer from anybody.

Thanks in advance.


5 Replies Last Post 2016年2月3日 GMT-5 10:05

Please login with a confirmed email address before reporting spam

Posted: 9 years ago 2016年1月29日 GMT-5 07:24
Hi Chironjeet,

you can store your time-temperature data in txt file and then import it into COMSOL. You can do this under definitions, then right click and choose function => interpolation. Here you can choose your txt file as input and import it. Here you must also choose a function name for this interpolation (e.g. my_temp). Instead of assigning a constant temperature at a boundary, you do now enter my_temp(t).

Kind regards,

Peter
Hi Chironjeet, you can store your time-temperature data in txt file and then import it into COMSOL. You can do this under definitions, then right click and choose function => interpolation. Here you can choose your txt file as input and import it. Here you must also choose a function name for this interpolation (e.g. my_temp). Instead of assigning a constant temperature at a boundary, you do now enter my_temp(t). Kind regards, Peter

Please login with a confirmed email address before reporting spam

Posted: 9 years ago 2016年1月29日 GMT-5 07:38
Hallo Peter,

Thank you very much for your suggestion. Can you tell me one more thing, where should i put the unit of time and temperature.

Best Regards,
Chironjeet.
Hallo Peter, Thank you very much for your suggestion. Can you tell me one more thing, where should i put the unit of time and temperature. Best Regards, Chironjeet.

Please login with a confirmed email address before reporting spam

Posted: 9 years ago 2016年1月29日 GMT-5 08:56
Hi,

It is at the bottom under the interpolation node (under units).

KInd regards,

Peter
Hi, It is at the bottom under the interpolation node (under units). KInd regards, Peter

Please login with a confirmed email address before reporting spam

Posted: 9 years ago 2016年2月3日 GMT-5 06:32
Hallo Peter,
I have one question to you. May be it's a stupid question but i'm really confused.

I am running transient thermal simulation where i set the time dependent temperature function (interpolated), looks like:

1 297
2 298
... ....
236 533

So here final time is 236 second and final temperature is 533 Kelvin. If i put the function in one end of domain as boundary condition and if i select the time dependent study for 30 mins, then how comsol will calculate the temperature distribution over the whole domain for the set function. I mean, should i select 236 second in the time dependent study section? or i can select any time. My aim is to see the temperature distribution over the whole domain according to the function what i set initially, so i want to run the simulation until the final time of my set function.

Can you please give me an explanation which will reduce my confusion.

Thanks in advance.
Hallo Peter, I have one question to you. May be it's a stupid question but i'm really confused. I am running transient thermal simulation where i set the time dependent temperature function (interpolated), looks like: 1 297 2 298 ... .... 236 533 So here final time is 236 second and final temperature is 533 Kelvin. If i put the function in one end of domain as boundary condition and if i select the time dependent study for 30 mins, then how comsol will calculate the temperature distribution over the whole domain for the set function. I mean, should i select 236 second in the time dependent study section? or i can select any time. My aim is to see the temperature distribution over the whole domain according to the function what i set initially, so i want to run the simulation until the final time of my set function. Can you please give me an explanation which will reduce my confusion. Thanks in advance.

Please login with a confirmed email address before reporting spam

Posted: 9 years ago 2016年2月3日 GMT-5 10:05
Hi,

I am not sure if I understand your question correctly. If you simulate until 236 seconds, your boundary will take the assigned values during the simulation. If the simulation time extends the 236 seconds, it depends on the extrapolation you chose at the interpolation node. The default seems to be constant, so that your boundary will have a temperature of 533 Kelvin in the interval from 236 seconds to the end of the simulation.

Kind regards,

Peter
Hi, I am not sure if I understand your question correctly. If you simulate until 236 seconds, your boundary will take the assigned values during the simulation. If the simulation time extends the 236 seconds, it depends on the extrapolation you chose at the interpolation node. The default seems to be constant, so that your boundary will have a temperature of 533 Kelvin in the interval from 236 seconds to the end of the simulation. Kind regards, Peter

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.