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updating boundary condition

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hi Ivar
I am doing flow through porous media analysis. In this, I would like to update my boundary condition from my previous time step values (for first time step I gave my BC, for the second time step I would like to use the result from first previous time step as a BC . please do not confused with initial conditions ).
is it possible to update boundary conditions in comsol .
if so , please give me the details .


thank you
regards
vishwesh

1 Reply Last Post 2012年2月23日 GMT-5 15:51
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago 2012年2月23日 GMT-5 15:51
Hi

it is not something I have tried out, not sure ho COMSOL would react, but you can set an expression depending on a sweep parameter, or depending on the ntime "t" in any BC expression.
And in v4.2a you ave a special, new, operator to get access I believe to the previous time step, not sure it allows you to read the solver step previous BC value though.

Once solved you have the at() and with() operator to dig into your data set at given parameter, eigenfrequency or time values. Check the doc its all in there, use an indexer on the pdf to find back the keywords

--
Good luck
Ivar
Hi it is not something I have tried out, not sure ho COMSOL would react, but you can set an expression depending on a sweep parameter, or depending on the ntime "t" in any BC expression. And in v4.2a you ave a special, new, operator to get access I believe to the previous time step, not sure it allows you to read the solver step previous BC value though. Once solved you have the at() and with() operator to dig into your data set at given parameter, eigenfrequency or time values. Check the doc its all in there, use an indexer on the pdf to find back the keywords -- Good luck Ivar

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