Use or reference buildlayers() layers individually?

Hi all,

I’m trying to use FreeFem in my “temperature reached while drilling a hole with a drill bit” problem, that I posted a few days ago.

So far, I’ve a 3D mesh build from a 2D mesh using buildlayers(), with lets say 100 layers.

In the 2D mesh, there’s a circular region defined by a border. This creates a region inside the border. This region is the drill bit diameter.

In the 3D mesh, the down and up surfaces of this circular region can be identified. But, is there any way to identify and reference the individual middle layers?

I can reference the whole middle (cylindrical) surface, and using a function of z in an int2d() integral, apply a heat flux only over a small z-length area of the cylinder at a position z(t), function of time. But I need also to consider the heat flux through the frontal disc area at position z(t), which I can assimilate more or less to one of the circular layers of the buildlayers() process.

I don’t figure out how to do that, if such thing is even possible ¿?