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How to find gradient of temperature in 3D thermoelectric geometry ?

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Hello everyone,
I have this problem since 2 months ago, and I didn't resolve it,
I have a thermometric 3D geometry (as shown in picture in files), also I used the configuration in below
I didn't find any way to measure the gradient (delta T) between (A and B).
can you help me in my urgent case ?
Thank you,


1 Reply Last Post Jul 29, 2017, 8:22 a.m. EDT
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 7 years ago Jul 29, 2017, 8:22 a.m. EDT
Hi

A thermal gradient being (Delta T)/(Delta distance) my understanding of your issue is how to define which DT and which DL. You may calculate the average temperature with an average operator on a cut line Data Set at the two locations, and as you know then also the DL you write out the equation.

This is either performed by adding Definitions coupling operators (but then you need a "boundary" to average over, hence you must "cut/split" your geometry), or you do in in the Results Global Evaluation region, cut line Data sets and add some operators here, but then you must manually calculate the gradient from the two temperatures you get and the known distance. As COMSOL does not (yet ?) allow to refer to post processing variables defined in the tables.

Check the "how to" videos about post processing your data on their web site

--
Good luck
Ivar
Hi A thermal gradient being (Delta T)/(Delta distance) my understanding of your issue is how to define which DT and which DL. You may calculate the average temperature with an average operator on a cut line Data Set at the two locations, and as you know then also the DL you write out the equation. This is either performed by adding Definitions coupling operators (but then you need a "boundary" to average over, hence you must "cut/split" your geometry), or you do in in the Results Global Evaluation region, cut line Data sets and add some operators here, but then you must manually calculate the gradient from the two temperatures you get and the known distance. As COMSOL does not (yet ?) allow to refer to post processing variables defined in the tables. Check the "how to" videos about post processing your data on their web site -- Good luck Ivar

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