__I
. CONSTRUCTION OF THE GEOMETRY__

This is a simple box with a circular bump. We used the
manuel PREBFC with the aim of modelising the domain. It is a box
: x = [0, 41] and y = [0, 20] in which we have defined the bubble at the
position

[x,y] = [20,0] . The diameter of the bubble is one centimeter.

We choose an unstructured mesh due to the particular geometry
of the frontiers. A uncartesian and structured mesh may have been better
but it would have been much more difficult to define . In order to refresh
the mesh, we have changed the number of nodes and their distribution
on the bottom frontier (before, after and on the bubble).

We obtain the following results :

Besides, in order to study the circulation in downstream
from the bubble, we have refined the mesh with the menu adapt in Fluent.

A view of two different meshes in this region is shown
on the next figure :

In a first time :

and with the gradient adaption fonction :

at least, with the region adaption fonction :