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dT/dt

Posted 26.02.2013, 13:30 GMT-5 3 Replies

Faizan Javed
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Hi

I cannot work out how to get dT/dt ( temperature variation rate) when using COMSOL. I am a beginner and currently using a version 4. I am modelling the heat transfer of a thin pyroelectric solid and I do not know how to get a plot of dTemperature/dTime against time. I have attached a paper below which pretty much gives the results I am looking for. I just need to work out how they did it.


Thanks

Faizan
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3 Replies Last Post 28.02.2013, 01:46 GMT-5
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)
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Posted: 1 decade ago 27.02.2013, 02:26 GMT-5
Hi

if you solve for T (temperature (as in HT) then COMSOL makes the variable Tt readily for you Tt is DT/dt

Check carefully the doc and help for all internal variables, and/or turn on the preferences equation view

--
Good luck
Ivar
Hi if you solve for T (temperature (as in HT) then COMSOL makes the variable Tt readily for you Tt is DT/dt Check carefully the doc and help for all internal variables, and/or turn on the preferences equation view -- Good luck Ivar
Faizan Javed
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Posted: 1 decade ago 27.02.2013, 22:19 GMT-5
Hi thanks alot for the help!


I also have a couple more problems

1. How do you change range of the x axis and y axis when your plotting a line graph for a dot within your structure. I am trying to dT/dt against seconds . But I need to reduce the time range between 1e-07 to 1e-02.

2. I have lots of colorful lines but I want just one line how do I get this. I have attached a document to show what I mean. I have also attached a paper which has the graph which i want to plot

3. The project I am using COMSOL for is a pyroelectric cell rengtangle exposed to 30 degrees. I have set the top line of the rectangle as 30 degree and the other three lines as thermal insulation. Is this correct ?? I have explained more on the document below.


Hi thanks alot for the help! I also have a couple more problems 1. How do you change range of the x axis and y axis when your plotting a line graph for a dot within your structure. I am trying to dT/dt against seconds . But I need to reduce the time range between 1e-07 to 1e-02. 2. I have lots of colorful lines but I want just one line how do I get this. I have attached a document to show what I mean. I have also attached a paper which has the graph which i want to plot 3. The project I am using COMSOL for is a pyroelectric cell rengtangle exposed to 30 degrees. I have set the top line of the rectangle as 30 degree and the other three lines as thermal insulation. Is this correct ?? I have explained more on the document below.
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)
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Posted: 1 decade ago 28.02.2013, 01:46 GMT-5
Hi

well I cannot tell, but when I do a simple model (4.3a below) it works OK

--
Good luck
Ivar
Hi well I cannot tell, but when I do a simple model (4.3a below) it works OK -- Good luck Ivar

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