Learning Forum

[Tino Damian]

Hello!

I am new to Ansys Fluent and I have a question regarding UDFs and UDSs.

I'd like to model a special case of diffusion governed by non-conventional equations, provided below.

The first equation is the diffusion equation and well known.

The second equation is an alterted version of Ficks's first law, including a term taking the conformational changes of a material the species diffuses through into account. 

The third equation describes the time-evolution of the material's changes.

All variables will be scalars as I will model the diffusion only in 1-D.

As far as I can tell, simple cases of Fickian diffusion are modelled analogously via heat conduction.

I would like to know if it is even possible to adapt the default equations and add necessary ones to include the full model I want to implement, via UDFs and UDSs.

If so, which UDFs would I need to use?

Thanks in advance,

Tino

[Rob]

Possible, yes. Easy, very definitely not. You'll probably need to use User Defined Scalars and write the diffusion model but it's not a project I'd even consider as a relatively new user. Ansys staff are also very limited in what advice we can offer, and UDFs are generally beyond where we can help. 

[Tino Damian]

Hey Rob,

thanks for the quick answer! I'll be working my way through the User, Theory and UDF guides and see if it'll be possible for me.

[Rob]

Don't forget the courses under Learning, left upper on here.