Learning Forum

[EL_G]

hello;

I'm simulating a 2D liquid piston model (water vs air) along with the Species Transport activated. During the compression process, oxygen and nitrogen molecules in the air (21% o2 + 79% n2) is dissolved in the water (liquid piston) and the goal is to monitor them. The mesh is set on the global quad. The Residual Absolute Criteria for all equations is set by default on 0.001 and the Time Step Size [s] is 1e-5.

Following running the model based on the below Solution Methods set-up, it is seen that the continuity residual doesn't come below the defined absolute criteria (0.001). I think this is a kind of divergence, although the simulation is not failed.

Actually, I can't find any mistake in the model set-up, however, my concern is with setting the Solution Methods (P-V Coupling, Discretization & Transient Formulation).

Any advice and help will be highly appreciated.

[Rob]

How are you setting the mass transfer between the phases? If you look at the flow speed relative to the mesh, how long does the flow take to cross one cell?

[EL_G]

Hello Rob and thanks for your reply.
The mass transfer between phases is modelled through:
Multiphase(Eulerian) --> Phase Interaction --> Henry's Law
Species Transport
Below are the screenshots of the mass transfer setup for your reference.
Regarding the cell crossing time, it takes 7.6e-3 [s] at the inlet.
Regards.