[willsen]

Hi Everyone!

I created a textile unit cell in TexGen and planning to run a flow simulation (to do permeability prediction) by using ANSYS CFX. To model the flow inside the fibrous tows/yarns, I am planning to use the momentum porous loss model of type "superficial velocity formulation" in which I can assign the permeabilities within the fluid sub-domains (which in this case is the tows).
However, the adoption of this method requires us to specify the "stream-wise direction", which is assigned 'globally' to the considered sub-domains.
My questions are:
1. Is there a way that we can assign this "streamwise directions" to each of the tow elements according to their principal direction? The principal direction is the direction of the tow path.
My supervisor advised me to find a way to change the orientation of the local coordinate system of each of the tow elements so that they are alligned to the principal direction.
2. Does anybody have similar experience that can suggest a more efficient way to do this?

In the worst scenario, I might be able to just dividing the tows into several chunks of sub-domains in which I can assign a unique streamwise direction to each of these sub-domains. But even with this method,I don't know how we can separate a geometry in ANSYS so that we can choose different volumes within the same geometry.

For your reference, I attach a picture of a textile unit cell.