Pressure drag problem in porous media with interFoam
 

Hi

I am modeling vacuum assisted resin transfer molding (VARTM), and I want to capture the resin flow front in the fiber reinforcement. For that, I have added porous media to interFoam.

I have a block with two parallel porous zones with different permeability, inlet at one patch and outlet at the opposite patch.

My problem is that there are no flow though the thickness, because there is no pressure difference between the two phases where the block is partly filled. Please see the attachments.

Is it possible to define a constant pressure for my air phase with interFoam, which provides a pressure drag normal to the phase interface?

Thanks
Simon

Hi Simon,
did you manage to simulate VARTM until now?
I'm also trying to simulate the RTM process and maybe we could reactivate this thread.

Greetings, Alex

Hi:
have you manage to simulate RTM ?can we continue this thread ?thank you ....

Hi Liaoning,
First of all I got access again.. :-)

Shortly after I was struggling with that model a new version was released incl. porousInterFoam. This solver looks promising for RTM simulation.

But the porous media implementation is not made for defining fabrics in most real parts, or its just my skills..?
Do you have experience with that?

bg
Simon

Hi skp,

I´m actually struggling with porousInterFoam :)

What do you mean with "is not made for defining fabrics in most real parts"? I hope to be able to define porosity zones based on experimental results... once I´ve managed to made porousInterFoam work :S

Until now I have only got the following error:

FOAM FATAL ERROR:
cannot find porous cellZone porosity

Any idea about that?

Thanks in advance

Paula

Hi Paula

The parts I have in mind was advantaged composites like wind turbine blade, aircraft fuselage panels etc.
These parts all have in common, that they are made of fabrics which are draped onto curved surfaces, and subsequently infused or injected with resin. The permeability and porosity properties of each fabric are measured on flat layups to obtain the two in-plane and the out-of-plane principle permeability values and directions.
Due to the definition of porous zones the mesh must be divided in cell zones based on fabric type and orientation. So actually I’m just whining that I need to define a lot cell zones and porous zones or make a script to generate it all :-)

Your error is properly just because the cell zone named "porosity" is not defined. If you are using blockMesh, the cell zones can be defined by adding name in the block section like this:

hex (0 1 2 3 4 5 6 7) porosity (5 5 5) simpleGrading (1 1 1)

bg Simon

Hello Simon,

Yes, I fear that you are right. Setting different permeability and porosity properties seems to be a cumbersome process. Maybe an script could help you. Sorry that I can´t help you with it now :( But in fact, this is the point I hope to reach one day!

Now I´m struggling with the basic error I told you about. I´d already defined the porosity as you indicated but the error persists.

I thought it had to do with my version of OF so I installed the version 2.3.0 but no luck.

BR

Paula

Hi Paula

You get that error massage from the porosityModel constructor (see line 136 in porosityModel.C). So check the presence of the cell zone name in <case>/constant/polymesh/cellZones after running blockMesh. Offen bugs are quiet obiviously when you first find them :-) so remember checking case sensitivity and similar.

/Simon

Thanks Simon! :)