Reply To: Want to know how to set a specific concentration in an area

[albertocaracuta]

Hi, sorry to bother you again.

I actually tried to scale up my system in order to understand if the problem with my simulation was just related to dìthe dimensio of the system, but actually is not.

i'll try to explain better my problem, as you can see in the image, i have a surface in which i put a mixture of water+sodium, and after the interface there is another surface with just pure water, what i want to do is to configure the system in order to have at time=0 a defined mass fraction of sodium only on the left part of my system, and pure water on the right part.

I tried by using a patch (also on the macroscopic system), defining the mass fraction of sodium i want just in the left surface of my system, but when i check what the patch has done the sodium is spread in all the system and not just in the left section, could be a problem of the mixture? or i'm using in a wrong way the patch function?

Thank you