What is simulated?

As explained previously, we will try to modelise the climbing of a bubble in a column of water, thanks to the gravity forces alone.
Here is a picture that shows what we are expecting.

The experiment
- Our study -

Our initial state will be set with no velocity at the inlet, nor at the outlet, and the pressure will be taken equal to the atmospheric one.
We will have to think about the conditions to put on the borders (symmetry, periodic, wall), as well as at the in and outlets.
We can already note that we will use the axisymetric solver of Fluent, because it would be too bad to forget that the bubble evolves in the space. This problem could hardly be reduced to a 2D problem!
As for the dimensions, we will make a calculation for different size of bubbles. We will then have to modify the size of our domain, as well as the grid and the size of the cells.