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coupled nonlinear odes: bvp

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can i solve my own model of coupled nonlinear odes (bvp)

5 Replies Last Post Jan 29, 2013, 2:45 a.m. EST

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Posted: 1 decade ago Jun 2, 2010, 7:51 a.m. EDT
You can solve ODE's in Comsol. In Comsol 3.5a look at the global equations under physics menu. There are very nice examples in the documentation on how to do it.
You can solve ODE's in Comsol. In Comsol 3.5a look at the global equations under physics menu. There are very nice examples in the documentation on how to do it.

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Posted: 1 decade ago Jan 28, 2013, 2:49 a.m. EST
can i solve the attached model
can i solve the attached model


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

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Posted: 1 decade ago Jan 28, 2013, 6:54 a.m. EST
Hi

you need to reexpress your model to fit into the parameters of the standard COMSOL PDE equations. You might need to define intermediate variables and new BC for these

--
Good luck
Ivar
Hi you need to reexpress your model to fit into the parameters of the standard COMSOL PDE equations. You might need to define intermediate variables and new BC for these -- Good luck Ivar

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Posted: 1 decade ago Jan 29, 2013, 12:26 a.m. EST

Hi

you need to reexpress your model to fit into the parameters of the standard COMSOL PDE equations. You might need to define intermediate variables and new BC for these

--
Good luck
Ivar


Hi
thanks for response. Please let me know what do you mean by new bc for these equations.

khalid
[QUOTE] Hi you need to reexpress your model to fit into the parameters of the standard COMSOL PDE equations. You might need to define intermediate variables and new BC for these -- Good luck Ivar [/QUOTE] Hi thanks for response. Please let me know what do you mean by new bc for these equations. khalid

Magnus Ringh COMSOL Employee

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Posted: 1 decade ago Jan 29, 2013, 2:45 a.m. EST
Hi,

I don't think you need to define any intermediate variables. That is typically only necessary if you have derivatives of order higher than 2 in your equations. I would formulate this as two coupled 1D PDEs along a line from 0 to 1 with two dependent variables: n and T (using a single Coefficient Form PDE in COMSOL). The equations look quite nonlinear but should be possible to solve.

Best regards,
Magnus Ringh, COMSOL
Hi, I don't think you need to define any intermediate variables. That is typically only necessary if you have derivatives of order higher than 2 in your equations. I would formulate this as two coupled 1D PDEs along a line from 0 to 1 with two dependent variables: n and T (using a single Coefficient Form PDE in COMSOL). The equations look quite nonlinear but should be possible to solve. Best regards, Magnus Ringh, COMSOL

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