Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.
PDE
Posted Jan 27, 2011, 12:20 a.m. EST 3 Replies
Please login with a confirmed email address before reporting spam
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 Jan 27, 2011, 1:19 a.m. EST
Please login with a confirmed email address before reporting spam
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
Please login with a confirmed email address before reporting spam
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
Please login with a confirmed email address before reporting spam
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