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quick help please! electrostatic module

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is there possible to change the temperature in electrostatic without adding a new model?

i am working with electrodes and i need to find out if the temperature changes the field line.
please i need urgent help

3 Replies Last Post Mar 14, 2011, 9:22 a.m. EDT
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago Mar 14, 2011, 8:15 a.m. EDT
Hi

what phenomena should be temperature dependent in ES ? I must assume (as you do not tell) its i.e. a material constant. If the temperature is constant in the full model (or domain OR you can express it as a simple analytiacl function T(x,y,z) then YES you can:

Define a temperature PARAMETER as T or T0
define a function "ana1()" that maps this temperature over the field

call the material parameter with a T0*ana1(x,y,z)

Note: when you write just "T" in HT for the temperature you are in fact calling for the field T(x,y,z) (in 3D) but COMSOL assumes by default this (x,y,z) dependence and you do no write it out fully. with an analytical function you must do it.

This means that the ana1(x,y,z) will take x,y,z values from the operation (integration scan over entity linked to the way the formula is used inside COMSOL. (not sure I made myself clear now, hope so ;)

PS that was fr V4, for v3.5 you need t use a function call instead of the "ana1()" term, but it's the same


--
Good luck
Ivar
Hi what phenomena should be temperature dependent in ES ? I must assume (as you do not tell) its i.e. a material constant. If the temperature is constant in the full model (or domain OR you can express it as a simple analytiacl function T(x,y,z) then YES you can: Define a temperature PARAMETER as T or T0 define a function "ana1()" that maps this temperature over the field call the material parameter with a T0*ana1(x,y,z) Note: when you write just "T" in HT for the temperature you are in fact calling for the field T(x,y,z) (in 3D) but COMSOL assumes by default this (x,y,z) dependence and you do no write it out fully. with an analytical function you must do it. This means that the ana1(x,y,z) will take x,y,z values from the operation (integration scan over entity linked to the way the formula is used inside COMSOL. (not sure I made myself clear now, hope so ;) PS that was fr V4, for v3.5 you need t use a function call instead of the "ana1()" term, but it's the same -- Good luck Ivar

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Posted: 1 decade ago Mar 14, 2011, 9:00 a.m. EDT
i am working in vs 3.4. is there any differences?i am working in 2D.
i have 2electrodes in air(gap distance 1mm), one is grounded and one has potential of 3600V. i need to show if at that potential, changing the pressure(lower) and the temperature(higher) it makes any differences at the way discharge happens.
thank you a lot
i am working in vs 3.4. is there any differences?i am working in 2D. i have 2electrodes in air(gap distance 1mm), one is grounded and one has potential of 3600V. i need to show if at that potential, changing the pressure(lower) and the temperature(higher) it makes any differences at the way discharge happens. thank you a lot

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

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Posted: 1 decade ago Mar 14, 2011, 9:22 a.m. EDT
HI

i believe not, but Parameters are Constants and the ana1() are "functions"

--
Good luck
Ivar
HI i believe not, but Parameters are Constants and the ana1() are "functions" -- Good luck Ivar

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