[kayne91]

Hi there,

I am trying to simulate an ion diffusion process through a nano-channel using Species transport model. I have created a mixture of CO2 and water with water being the bulk species and set up a concentration gradient of CO2 across the top (inlet) and bottom (outlet) of the channel. The inlet velocity is set to 0 as i do not want any convective fluid flow, only pure diffusion.

When i run the process, i realised that both CO2 and water are diffusing through the channel at the same time (which is expected). My main concern is how do i allow only CO2 to diffuse through while making water as the background stationary fluid in the channel where CO2 will travel.

Does anyone know what should i change in the setup?

I tried removing water from the species mixture, leaving only CO2. but by doing so, i could not set up a concentration gradient under the boundary conditions of inlet and outlet.

Can anyone provide some advice here? Thanks in advance!