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PDE
Posted 27.01.2011, 00:20 GMT-5 3 Replies
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Hi all,
if I have 3 nonlinear PDE (time independent problem) with 2 dependent variables and one unknown constant.
I found the PDE solver solves the dependent varibles only.
If I wrote this constant the comsol asked me to enter its value
how to determine the constant ??
if I have 3 nonlinear PDE (time independent problem) with 2 dependent variables and one unknown constant.
I found the PDE solver solves the dependent varibles only.
If I wrote this constant the comsol asked me to enter its value
how to determine the constant ??
3 Replies Last Post 27.01.2011, 01:19 GMT-5
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Posted:
1 decade ago
also I would like to ask if I have some functions function of x and the others function of x and y how to express that
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Posted:
1 decade ago
Hi
if you are working fully in PDE global mode, I would say, that your "constant" has to be defined as a global equation and found by COMSOL (in a mean square way). But this means too that you must be careful to define enough independent BC's to solve uniquely the system. A variable that is depending only one one coordinate variable, has for me a Domain condition i.e that its gradient si 0 along that direction, or you could probably use one of the coupling variables.
But it's true, I have not used COMSOL as a math tool, too interested in the physics ;) perhaps I should do more, as this is helping, I believe, to better grasp what is really happening inside
--
Good luck
Ivar
if you are working fully in PDE global mode, I would say, that your "constant" has to be defined as a global equation and found by COMSOL (in a mean square way). But this means too that you must be careful to define enough independent BC's to solve uniquely the system. A variable that is depending only one one coordinate variable, has for me a Domain condition i.e that its gradient si 0 along that direction, or you could probably use one of the coupling variables.
But it's true, I have not used COMSOL as a math tool, too interested in the physics ;) perhaps I should do more, as this is helping, I believe, to better grasp what is really happening inside
--
Good luck
Ivar
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Posted:
1 decade ago
Thans Ivar. I will try to use your advices.It will be useful God willings.
Wait 4 other questions plz
My Regards
Wait 4 other questions plz
My Regards