Multiple flow volumes Tank with diffuser grids

Project Support
1

Hello There,

I am doing for test purposes a simulation we have already done of a chilled water tank transient.
The way I created my model is by importing the geomtery of my tank which is fitted with two diffuser pipes (with grids on it).
So I created three flow volumes for inside the tank, inside the two pipes.
I deleted the pipes and vessels, and kept only the two volumes I have representing the grids of the diffusors I intend to model by porous media.

Up to setting up everything that worked fine, but then i tried to generate the mesh I get this error:

image
image1195×372 30.7 KB

I am not sure if what I have done is allowed (having three flow volumes and two CAD volumes).
I guess maybe they should be joined inside a single volume.

In that case how could I keep track of the grid volumes to model them by porous media?

Thanks a lot,

Antoine

My simulation is

Ballon | SimScale Workbench

2

Hi @achupin, thanks for posting

This should be allowed for specific simulation types such as Conjugate heat transfer, but keep in mind the flow regions would not interact with one another. What is it that you’re trying to simulate?

As to the porous media definitions, you’d need to model them as Advanced Concepts. Take a look here for more information: Porosity & Porous Media | Advanced Concepts | SimScale

Cheers
Igor

3

Thanks for your answer.
I do a convective heat transfer simulation which is sufficient for me.

The modelis done for studying a transient in a chilled water tank.
The inlets and outlets of the tank are fitted with diffusion grids in order to avoid flow speed and inertial mixing on inlets and outlets.

I have done my CAD by modeling the volumes of the grids hoping I could directly declare them as porous medium which is not the case. The grids volume are half annular cylinders, which seemed difficult for me to declare after merging all the volumes in a single flow volume.

If you look in my model I have three flow regions (inside the tank, 2 inside the inlet and outlet pipes) + 2 grid volumes.
As I understand as my flow is going through all volumes I would have to merge all volumes. In that cas, I would still need to declare the grids volumes or equivalent as porous media, but I do not know how to simply do it.

Thanks

4

Hi @achupin

Convective Heat Transfer will only allow for a single fluid region! For multiple region assignments, please use the Conjugate Heat Transfer solver instead.

Cheers