  Thanks to ultra fast and high resolution X-ray tomography, we managed to
capture the evolution of the local structure of the bubble network of a 3D foam
flowing around a sphere. As for the 2D foam flow around a circular obstacle, we
observed an axisymmetric velocity field with a recirculation zone, and
indications of a negative wake downstream the obstacle. The bubble
deformations, quantified by a shape tensor, are smaller than in 2D, due to a
purely 3D feature: the azimuthal bubble shape variation. Moreover, we were able
to detect plastic rearrangements, characterized by the neighbor-swapping of
four bubbles. Their spatial structure suggest that rearrangements are triggered
when films faces get smaller than a characteristic area.
