[tehzap]

Hey,

I am trying to simulate a multitubular reactor which contains 30.000 single tubes through a porous media. Unfortunately I don't really get how to setup the directional loss model for an anisotropic media.
The flow enters the reactor from above. As it flows through single tubes it is only able to flow in one direction (x- and z directions represent the walls of the tubes).
As far as I understand the model I have to setup the streamwise loss using the permeability. For transverse loss I chose the streamwise coefficient multiplier to be 10, which means that the permeability in x- and z-direction is ten times higher than in y-direction, am I right?
Now there's my problem with the streamwise direction. What do I have to enter into the Cartesian components? When I leave x and z zero, the fluid just flows through the middle of the porous media without spreading into x- and z-direction, that's how I expect it to be. When I enter x/y/z = 1/1/1 instead the velocity seems to be identical in the whole porous media right from the beginning. So I can't really check whether this is the right solution.

Thanks in advance,
tehzap!