Learning Forum

[Honig]

Hello everyone,

I hope you are well.

Currently, I am studying the flow of oil through porous media. For that, input about the inertial resistance factor C_2 is needed. The ANSYS help provides an equation based on the Ergun equation that allows me to find a value for C_2 (see attached).

Epsilon is described as the "void fraction, defined as the volume of voids divided by the volume of the packed bed region".

As far as I understood it, it is the "empty" volume in the porous region divided by the entire volume of the porous region, so basically the porosity, which I calculated earlier in a different step.

Is that assumption correct or am I missing something?

Thanks for your input!

Best regards

[DrAmine]

That is how a packed bed can be modeled: is you porous media similar to a packed bed? If yes you might use the formula to estimate the coefficients, if not you require data to make that estimate.

[Honig]

Hello Amine,

thank you for your reply.

My porous media resembles a flat sheet of nonwoven material, which only is the middle part of the entire simulated region (a simple cylinder). If that does not count as a packed bed for the flat porous region, the data I'd need for other ways to calculate C_2 is not available in my case.

Can/could the the inertial resistance be omitted for slow laminar flows?

Best regards

[DrAmine]

Yes it can be omitted and you focus one the viscous term.