📚[DOC]: No such thing as a Darcy PDE

[ChristopherFowler]

How would you describe the priority of this documentation request

Medium

Is this for new documentation, or an update to existing docs?

Update

Describe the incorrect/future/missing documentation

I work in the field of multiphase flow and transport through porous media. There is mention of a `Darcy PDE' in the documentation. No such equation exists. You can sort of prove this by googling Darcy PDE and note that only Nvidia says it is a thing.

The term Darcy is reserved for a few things in the literature: The Darcy scale, which is the macroscale in more modern vernacular. Another use is the Darcy velocity (q = v * porosity) in Darcy's law, which relates q to the pressure gradient across the media. You can get away with saying Darcy flow so long as there is a linear relationship between the Darcy velocity and pressure gradient, otherwise you may have a non-linear Darcy-Forchheimer flow. Still, there is no Darcy PDE.

If this is a correction, please provide a link to the incorrect documentation. If this is a new documentation request, please link to where you have looked.

https://docs.nvidia.com/deeplearning/modulus/modulus-v2209/user_guide/neural_operators/darcy_fno.html