# 'Test-cfd' simulation project by miro0315

#1

I created a new simulation project called 'Test-cfd':

Test cfd

More of my public projects can be found here.

#2

@miro0315 - How is the test going? Were you able to post-process the results?

#3

Hi, still learning.
Just thinking, I have a Wall BC’s but the meshing does not refine the mesh near to the walls.

#4

Hi, one question.
The model consist of 2 solids, is it possible to make a union of the solids, this would solve the problem with the BC for face nr. 4 of the cylinder (the top face connected to the box).

#5

Hi @miro0315, I made a copy of your project (have a look here: https://www.simscale.com/projects/AnnaFless/test-cfd). As you said, it’s a good idea to upload just a single solid in this case so I went ahead and downloaded your model and performed a boolean operation using Onshape (a cloud-based CAD tool which I highly recommend it for this sort of thing).

I also went ahead and performed a snappy hex mesh for internal flow which is preferred to the tet-meshing for CFD

I ran the simulation again (removing boundary condition 4). Feel free to make a copy of my project and have a look!

#6

I noticed that with Simulation 2 the residuals were spiking around iteration 700 (a numerical instability of some sort).

Increasing the distance of the inlet from where the indent of the pipe is helps, thus you will also see an extended pipe model (also done using Onshape).

The simulation setup is the same for this, however, the convergence plot looks much better

#7

Looks very impressive, how much CPU time were used?
Back to face nr. 4 on the cylinder, is there an BC which acts like a perf. sheet where the pressure drop is a function of velocity?

#8

Here is the computing time info:

#9

For this question, maybe @Ali_Arafat can jump in here?

#10

From the New geometry and simulation done by Anna, the 2 solids were combined as 1 solid.

So the " face nr. 4 of the cylinder (the top face connected to the box)" is not there anymore.

Also, for the boundary condition " which acts like a perf. sheet where the pressure drop is a function of velocity" could you explain a bit in detail what are you trying to actually model so that I can better help you.

Best,
Ali.

#11

Hi,

My question is how to indicate a flow resistance, like a filter or perf. plate.
By Autodesk CFD it is called a resitance, by Comsol it is called a screen when it is internal and a grill if it is external.
Likewise, is there a way to indicate a Fan, so it is possible to have the flow from a fan, without having to model it.

Thank you very much for your time.

Best regards