Learning Forum

[marioackermann]

Hi,

I need to model a fine-mesh net which generates a pressure drop in an airflow. The thickness of the net is less than 1 mm.

I tried a porous medium, but then I need a thickness of my mesh. The other option I tried was to model an interface pressure drop, but that doesn't damm up the flow adequately.

Are there any other options to model this net?

Thanks for your advise

[DrAmine]

You can mode that thin membrane as interface where you provide the pressure drop. 

[marioackermann]

Thanks for your response.

Problem is, that the streamlines aren't affected of that interface as showed in the pictures below.

What I would like to have is the effect with a porous domain (see picture below) but as an interface.

[DrAmine]

What you can try is to provide the same pressure drop as within the porous domain (using the same law and coefficient). Are you using true velocity for the porous region?

[DrAmine]

looks like you have a sudden enlargement like flow in your porous media. From the first screenshot even if not obvious, a small increase of the streamlines tube is there? can you recheck that? Bear in mind that pressure drop for the case of interface is only acting there (on interface) and the effect is felt downstream where with porous zone the effects is on the whole porous domain + downwards.

[marioackermann]

Probably, I didn't understand your question. But no, I use isotropic loss with the resistance loss coefficient for the porous domain.

The pressure drop is the same at the interface as on the porous domain. The enlargement is what I want to have because the flow streams through a diffuser and the membrane homogenizes the flow at the bigger cross section.

Yes, there is a small increase of the streamline. But the increase is almost constant and doesn't change at the interface.

OK, got the difference between the two options.

Thanks