Mass Diffusion Coefficient-help needed
 

For a multicomponent system where the mixture composition keeps changing(time -dependent) what model should I be using? The Fick's law or full multicomponent diffusion?Thanks.

Re: Mass Diffusion Coefficient-help needed
 

It depends on your concentrations: if you are using tracer-components (very low concentrations) Fick's law applies. If your concentrations are high you need the multicomponent diffusion.