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smoothing a parameter distribution

Michael Rembe Certified Consultant

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Hello,

in a Darcy flow problem there is a very hard step between the distribution of two parameter quantities (k=1e-8m²/1e-12m²). This causes numerical problems.

Has anybody a good idea how to smooth the transition? Is there a way using a pde to smooth the transition over a given interface thickness in a first stationary simulation step (comparable with the interface thickness of the level set method)?

I could use a transient pde and smooth by diffusion. But I don't want to get a time dependent problem.

Thank you very much!

Best regards
Michael

2 Replies Last Post 12 juil. 2017, 08:26 UTC−4
Jeff Hiller COMSOL Employee

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Posted: 7 years ago 12 juil. 2017, 08:06 UTC−4
Hello Michael,
If the interface between the two domains has a relatively simple shape you could simply explicitly prescribe a spatially-dependent function (based on the step function that is pre-implemented for you in the software, or not).
If on the other hand the interface between the two domains has a complex shape and it's not possible to find an explicit function, the following blog post might help:
www.comsol.com/blogs/tips-using-wall-distance-interface/
Best,
Jeff
Hello Michael, If the interface between the two domains has a relatively simple shape you could simply explicitly prescribe a spatially-dependent function (based on the step function that is pre-implemented for you in the software, or not). If on the other hand the interface between the two domains has a complex shape and it's not possible to find an explicit function, the following blog post might help: https://www.comsol.com/blogs/tips-using-wall-distance-interface/ Best, Jeff

Michael Rembe Certified Consultant

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Posted: 7 years ago 12 juil. 2017, 08:26 UTC−4
Hello Jeff,

using the wall distance interface is a very good idea, because it is a complex geometry! Thanks a lot!!

Best regards
Michael
Hello Jeff, using the wall distance interface is a very good idea, because it is a complex geometry! Thanks a lot!! Best regards Michael

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