Dynamics of 3D Real Foam Coarsening

Dynamics of a polydisperse 3D dry foam was experimentally investigated by means of a novel nondestructive method, more precisely by optical tomography associated to a foam reconstruction algorithm. The foam coarsening law obeys to a 3D extension of the classical von Neumann coarsening law of 2D foams. It is obtained as $〈V_f{〉}^{-1/3\mathrm{}}d〈V_f〉{/dt=k}^{\prime }(f-〈f〉)$. $〈V_f〉$ is the mean volume of $f$-faced bubbles, $k^{\prime }$ a diffusion constant equal to the single film gas diffusion coefficient, and $〈f〉$ is the mean number of faces per bubble.