Multiple regions

Using SimScale Fluid Flow / CFD
1

I want to simulate flow between two tanks, connected by a pipe, and at different initial pressures.

Is it possible to setup an internal fluid flow simulation with multiple regions such that I could assign each region a different initial condition? If not, is there another way to achieve this?

2

Hi @jcol!

I am not sure if that’s possible as the initial condition holds for the whole domain. Maybe you could define the pressure gradient between both tanks inside the pipe?

Best,

Jousef

3

Hi @jcol,

That could work or you can try just applying a pressure inlet that have different values for both inlets of the pipe which should be a sufficient representation of what I think you’re trying to simulate. Will have to test it out though.

Cheers.

Regards,
Barry

4

I would like to do a transient simulation and find how long it takes to get to equilibrium, so I was trying to avoid having pressure based boundary conditions. Maybe I am going about this wrong?

5

Hi @jcol,

Sorry for the delayed reply.

Hmm a simple case to perform but setting it up not as easy unfortunately. The issue is that I’m not sure how to assign say two different regions with different initial pressures because I understand you want to just let the difference in pressure dictate the time taken before it gets to equilibrium.

I’ll see what I can figure out. In the meantime maybe you can start drafting up a geometry and see what kind of boundary conditions you can assign.

Cheers.

Regards,
Barry

6

Here’s a simple geometry:

7

Hi @jcol,

Try using the Passive Scalar Transport simulation type. I don’t think incompressible will cut it. Do look around for public projects relating to this.

Cheers and good luck.

Regards,
Barry