I want to perform the flow simulation inside this U-shaped tank. However, I am having trouble defining the boundary conditions and subdomains. The tank just have two air vents on the top, in other words, the pressure inside is the atmospheric pressure.
Thanks in advance
Hello, thanks for posting in the forum!
As I mentioned earlier, the first step here is to use a solid geometry (sheet bodies are not allowed). The holes that were created in the geometry are actually making it hollow, which is not desired for simulations.
For the hole, I’d generally recommend making an extrusion to the top, which should work nicely:
The initialization is very simple. Basically the water and air materials will be linked to a phase fraction. For example:
All you have to do is to create a new subdomain (1), create a new geometry primitive (2) and define the coordinates to represent the water initialization, set the phase fraction to the one that corresponds to water (3) and assign it to the subdomain initialization (4).
The regions of your domain inside the box will be initialized as water in this case. The rest will be initialized as air.
For the “hole open to the atmosphere” boundary condition, the usual approach is this one:
I would, however, highly encourage you to read through these articles on multiphase analysis before attempting your simulation, otherwise you will likely have issues with runtime.
And of course, there is more material available on forums.