CFD Online Discussion Forums

CFD Online Discussion Forums (
-   CFX (
-   -   Modeling of particle absorption in air filter in CFX (

j-avdeev August 20, 2012 03:59

Modeling of particle absorption in air filter in CFX

I am trying to setup absorption efficiency of air filter. I have particles of different size and want setup, that air filter pass for example 1% of big particles, 2% of medium particles and 3% of small particles (filter retains 99% of big, 98% of medium and 97% of small particles).

I can find corresponding options (almost) for this case - in "wall" object, but can't find this in "interface" object and in porous media.

Is it possible to reach my goal with using interface? Or I have to use something like "user defined functions"? Or maybe it is possible with walls (I need that particles pass through surface)?

Thank you.

ghorrocks August 20, 2012 06:01

If you are doing this with Lagrangian particle tracking you will need a fortran sub routine to do this. If you are doing this with a Eularian model it can be done with a source term (I think).

j-avdeev August 20, 2012 06:27

ghorrocks, thank for your rapid answer.

Also can you tell - is it possible to solve this problem with using CFX Expression Language (CEL) or fortran only?

And if it will on fortran - can you show something for example? Or give a link, where I can find something close to my case.

ghorrocks August 20, 2012 06:46

If you are doing a Eularian this might be able to be done by a CEL expression.

But for Lagrangian particle tracking you will need fortran. I do not have an example to hand, but the documentation includes some examples of fortran for particle tracking. I think it is in the CFX-Pre manual.

j-avdeev August 20, 2012 07:37

Thank you, Glenn.

Also can you tell - where can I insert fortran code for interface? For wall - exist separate window, but I can not find same for interface.

Felggv August 20, 2012 10:40


It's kinda tricky to link FORTRAN routines with CFX. Many people had asked about it before, you can search for it later!

Revise the concept of what you're trying to do. CEL supports if statements besides another basic things (look at the manual) it's very useful and maybe you won't even need to use FORTRAN.

Good luck

All times are GMT -4. The time now is 21:03.