[Eriador]

Hi,

I would like to perform some analyses containing both internal and external flow at the same time.

For example, in an empty and completely sealed box, I would like to simulate an external flow with a certain velocity and observe the behavior of the internal fluid.

If I define the analysis as external and set a velocity, will this velocity also be applied to the internal volume?

I ran some simulations, and apparently, the internal fluid is not affected by the external air velocity defined in the wizard, but I would like to be sure.

I know there is the possibility of using the fluid subdomain function. However, what I noticed is that when defining the internal fluid’s velocity, pressure and temperature, they remain fixed (I could be wrong). I wouldn’t want these boundary conditions to be fixed. I would like the internal fluid to move freely, for example, when I insert a heat source inside this internal fluid.

Are these boundary conditions in the fluid subdomain just the initial condition of the fluid?

[native]

Hi Eriador,

Yes, it's possible to have two separate fluid domains. As you've expected, the conditions in the subdomain window serve as initial conditions. If you apply a heat source and gravitational force, a natural convection will develop.

Best regards
Florian

[Eriador]

Hi Florian,

Thank you for your help!