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capturing small rise in temperature
Posted Mar 10, 2014, 12:56 p.m. EDT Heat Transfer & Phase Change Version 4.4 2 Replies
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Hi,
I have a rectangular block where I have assigned a heat source (W/cm^3). My ambient temperature is 25 deg. First I assigned a high thermal load and recorded the peak temperature. Then I reduced it by factor of 10 and recorded the temperature again. After reducing it few times, I plotted the peak temperature. Initially, the temperature came down linearly then after a threshold , the peak temperature remained stuck at 25.1 deg.
This does not make scene. Is there a way I can increase the model sensitivity at extremely low thermal load.
Regards,
Susant
I have a rectangular block where I have assigned a heat source (W/cm^3). My ambient temperature is 25 deg. First I assigned a high thermal load and recorded the peak temperature. Then I reduced it by factor of 10 and recorded the temperature again. After reducing it few times, I plotted the peak temperature. Initially, the temperature came down linearly then after a threshold , the peak temperature remained stuck at 25.1 deg.
This does not make scene. Is there a way I can increase the model sensitivity at extremely low thermal load.
Regards,
Susant
2 Replies Last Post Mar 19, 2014, 2:44 p.m. EDT
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Posted:
1 decade ago
Hi Susant
Are you sure it's not just the round-off of the displayed values ?
anyhow 0.1/(273.15+25) (consider T in [K]) is only about <0.03% so it's not a "big error" I would say,
Have you checked the sensitivity to the relative tolerance for the solver ? try to lower it by a factor 10 or 100
Finally mesh size, and mesh sensitivity, but I suspect you have already a fine mesh compared to your problem's need
--
Good luck
Ivar
Are you sure it's not just the round-off of the displayed values ?
anyhow 0.1/(273.15+25) (consider T in [K]) is only about <0.03% so it's not a "big error" I would say,
Have you checked the sensitivity to the relative tolerance for the solver ? try to lower it by a factor 10 or 100
Finally mesh size, and mesh sensitivity, but I suspect you have already a fine mesh compared to your problem's need
--
Good luck
Ivar
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Posted:
1 decade ago
Hi Ivar,
You are correct. It was the round-off displayed value. After I changed the number of significant digit, it was ok.
Regards,
Susant
You are correct. It was the round-off displayed value. After I changed the number of significant digit, it was ok.
Regards,
Susant