Potential use of a porous domain?
 

Hi,

So I am working on this model working on different types of inlet diffusers to maximize diffusing within the room.

I successfully got results like the image with the streamlines. What I did was basically draw these extrudes and then do a Boolean-Subtract.

Now, I am working on a semi circle inlet diffuser as shown. However, I would like this to be porous. I would like to see how well the air is diffused if I have a semi circle enclosure with say 50% volume porosity.

Do I need to specify a new domain? Do I still do a Boolean subtract? I would rather not be specifying new domains as this is a rather large model and i ran into several issues with the interfacing (ended up not using ANSYS's default interfacer for the diffusers that have worked). Little lost here, help?

Porous regions can be sub domains. They do not need to be an entirely separate domain. But you will still need to define it as a region in your mesh so you can assign it as a porous domain.

So extrude it, and dont do Boolean?

What do you mean by "define it as a region in your mesh." I just have a pretty standard mesh (with a bunch of Edge Sizing).

You will need to make it a multibody part with the rest of the domain, and you will probably have to use a boolean subtract. Then when you define the domain put both regions (both the main region and the subdomain) in the domain definition, and make a subdomain with just the porous region in it.

Alright, I extruded it just like the photo. Now, I did a Boolean Subtract. Now I cannot select this body when I look for faces in the subdomain selection (Since after a Boolean Subtract that body does not exist anymore?)

Alright really need some help here.

How can I do Boolean Subtract AND define that as a subdomain (after a boolean it becomes part of the regular fluid body around it/the cuboid around it)?

Is there any way to define the porosity just within the geometry? So the Boolean subtract is just implemented on like 65% of the shape?

Your questions about the boolean subtract are best asked in the geometry and meshing forum.

But to define a subdomain you will need to somehow define a mesh region. You cannot define mesh regions in CFX-Pre.

Is there a way to possibly not use a subdomain or another domain but just use porous material? Like in the geometry?

I do not understand what you mean. You have to define a region for the solver to apply various physical models. The normal way of doing this is by defining mesh regions.

Could you please explain how to apply "various physical models"? All I ever learned how to mesh was the entire body at a time. How do I tell ANSYS, "Mesh these faces this way, and the other faces some other way."

Also, how will meshing differently help me model a perf metal/porous material?

It sounds like you need to do some meshing tutorials. Have a look at the ANSYS community website, or contact ANSYS support.

I think what Im gonna do is do "cut material" extrudes and make thousands of pores in the material in the geometry. It seems it will end up being a computationally heavy problem, but no reason why it wont work.

It seems porous domains are really making my interfaces go haywire and I need to input variable properties that I have never heard of before.

Haha it is taking 18 hours to converge, and just opening the results file is taking like an hour.

And I havent even done the pattern on all sides yet...too impractical?