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Finding Power of a device when you have Used Joule Heating Model

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I'm currently working on a device called micro-heater and I'm using COMSOL 4.2 for the purpose of my simulations.

I have used the Joule Heating model and have applied Terminal Current as the source of electric current to the device.

I'm getting the results for the temperature achieved but I'm also interested to get either the power consumed by the device or the voltage across the terminals of my device or both if possible.

Please suggest a suitable option for the same.


4 Replies Last Post May 30, 2012, 5:43 p.m. EDT
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago May 30, 2012, 8:49 a.m. EDT
Hi

if you have used a Terminal node, then go to the Results - Derived Variables - Global node and check the proposed terminal values, you will normally find the current and the voltage, their product should give you the power

--
Good luck
Ivar
Hi if you have used a Terminal node, then go to the Results - Derived Variables - Global node and check the proposed terminal values, you will normally find the current and the voltage, their product should give you the power -- Good luck Ivar

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Posted: 1 decade ago May 30, 2012, 9:32 a.m. EDT
Respected Sir

Thank you for your reply

As you had instructed I went to the Results --> Derived Values--> Global Evaluation--> Add Expression ("+"sign in green color) --> Added terminal voltage from Joule Heating(Electric Currents)

I then evaluated it

Got the error

Failed to evaluate variable.
-Variable: mod1.V
-Global Scope:
Failed to evaluate expression.
-Expression: real(mod1.V)
Failed to evaluate expression.
-Expression: real(mod1.V)

Please tell me what could be the problem.
Respected Sir Thank you for your reply As you had instructed I went to the Results --> Derived Values--> Global Evaluation--> Add Expression ("+"sign in green color) --> Added terminal voltage from Joule Heating(Electric Currents) I then evaluated it Got the error Failed to evaluate variable. -Variable: mod1.V -Global Scope: Failed to evaluate expression. -Expression: real(mod1.V) Failed to evaluate expression. -Expression: real(mod1.V) Please tell me what could be the problem.

Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago May 30, 2012, 9:36 a.m. EDT
Hi

do you happen to have several Data Sets ?
if so, are you sure your main Global Evaluation node is pointing to the right one ?

--
Good luck
Ivar
Hi do you happen to have several Data Sets ? if so, are you sure your main Global Evaluation node is pointing to the right one ? -- Good luck Ivar

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Posted: 1 decade ago May 30, 2012, 5:43 p.m. EDT
Thank You Sir for the help
I was giving the incorrect identifier for terminal voltage values.
Thank You Sir for the help I was giving the incorrect identifier for terminal voltage values.

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