Learning Forum

[Alejandro22798]

Hello! My name is Alejandro and I am a mechanical engineering student at a Spanish university. I am carrying out my final project, which consists of the simulation of a shell and tube exchanger. This exchanger has the peculiarity that a phase change material (PCM) is located inside the tubes and water cirulates inside the casing. My problem is that when I define the domains in the Mesh so that I can define them in the Set Up, I cannot "select" the same domain Body twice, and the see it in the Cell Zone Conditions. That is, my purpose is to define in the Set Up. for example, that the casing is made of steel and water circulates through it and the PCM tubes are made of steel and within them is the PCM that must not be moved from inside the tubes. I am attaching a phote of the domains and the exchanger (one of the covers is missing so that you can see the inside). Thank you very much to whoever can help me. A greeting.

[Karthik R]

Hello,

Are you able to create the necessary named selections (based on body) and send it to Fluent where you should be able to add the materials?

You will need to create separate named selections (volume-based) for each of the regions - casing walls, outer fluid (water), steel pipes, inner fluid region (PCM), and anything else (if you have).

You will not be able to group the same body twice in different named selections. Fluent will not be able to recognize this.

I'm not sure if that helps. If it does not, could you please elaborate some more (with additional images) on what Fluent is reading.

Thanks.

Karthik

[Alejandro22798]

Hello again! As far as creating selections is concerned, I am not able, because as I say, I select two Body domains that I want to behave differently at the same time for the same body (something that Fluent is not able to interpret).

The problem is that when for example instead of creating a Body I create a Face or Edge directly it sends it to me in Fluent to the Boundary conditions and there I cannot select the material or fluid that I want for example, I can only establish a condition of speed, pressure ...

I attach some photos of Fluent and Mesh of some example of these that I have commented on.

In the Fluent section, as you can see, I can only put the PCM as solid (steel) or fluid (pcm) but not do it both ways.

Since if I establish a Face it goes directly to the Boundary conditions, something that does not work for me.

Thank you very much for your attention.

[Karthik R]

If I understand your issue, the PCM walls are made out of solid 'Steel' and the fluid inside these walls is 'PCM'. Is you want to apply these material properties, then you will need to have a solid outer body (which is your solid pipe with its thickness) and this will be your 'Steel' region. The fluid inside the inner diameter of the pipe will be your PCM region. Right now, it seems like you only have the inner Fluid 'PCM' region in your domain. If you have the outer solid pipe, please create another named selection in Ansys meshing called 'Steel' and you should be seeing it in Fluent under 'Cell Zone Conditions'.

Thank you.

Karthik