Hi all,

I'm trying to use Fluent to model fluid flow thru porous media (simulating filling of a mold). I have a simple 2D geometry and I'm trying to solve for time dependent pressure distribution under constant flow rate conditions. I'm also trying to solve for the filling time of the geometry/mold. I'm trying to verify my results with 1 dimensional Darcy's Law.

1. Is FLUENT using Darcy's Law too, to solve porous media problems? Will FLUENT's results be comparable to 1D Darcy's Law solutions?

2. I have read a response on this forum that says, FLUENT is not very capable of solving porous media problems. Is that true? Is POLYFLOW better suited for these kind of applications?

3. With this type of problem, I'm using the following options:

* transient solver,superficial vel. formulation, * multiphase (2 phases, fluid displacing air inside the mold), * 3 types of boundary condtions, 1. VELOCITY INLET at the inlet side(since constant flow rate), 2. PRESSURE OUTLET at the outlet side(open to atmospheric pressure at outlet), and 3. WALLs at the sides of the geometry, * 2 materials, fluid=resin, and air, * solver= PISO, * porosity= 0.5, * viscous resistance= I take this as reciprocal of permeabilty, is that right??

and finally, not sure OR HAVE NO IDEA about:

should i change or play with the underrelaxation factors? what should be the number of iterations in Solve/Monitor/Residual/iterations? What should be the number of solve/iterate/time step size& number of time steps?

PLEASE HELP!!

all i can tell you that is that Fluent is not very good at porous media...and with multiphase i think you cannot use porous media but i am not sure about it....

Hi,

I am doing a CFD analysis of matrix heat exchangers.I am now facing a serious problem. When I mesh the fluid(gas)and solid(matrix sreens)separately and export it to FLUENT,there forms two walls.I am doing in FLUENT6.Should I change the solver? How to give conjugate/coupled condition in the thermal boundary condition? There doesn't appear 'coupled' in the option.Please respond.

Thanking you

[reynolds039]

hello,
for your first question, i confirm you that Fluent is really using the darcy's law to solve porous media problem, if you read the help of Fluent you will find it
-for the second question i confirm also that Fluent is able to resolve porous media problem ,
but if there's else software better i don't know
-for the third quesion i think i havethe same problem with you , so why did you use the same viscous resistance for the two fluid ?, (please help)

[zaynah04]

hi guys...

can You please help me on the fact that when i define porous jump in Gambit and then export it to fluent the message i get is

Cannot change porous to interior because
there is only one adjacent cell thread.
I am Lost please advice me
Thanks in Advance

zaynah