Measurement of anisotropic drainage in liquid foam using neutron radiography.

Transport of liquid through the foam is governed by the mutual effects of capillary, gravitational,
and inertia forces [Koehler, S. A. et. al. (2000)]. This process defines the distribution of liquid in
foam and is essential for industrial applications, e.g. production of polymeric and metal foams,
flotation etc. S. Neethling [Neethling, S. J. (2006)] have shown that sheared foam could not
anymore be considered as an isotropic media, and the direction of a drainage flow distinct from
the sense of a gravity vector. Thus, a non-uniform distribution of liquid in the foam is present.
This effect, for instance, has a major impact on a formation of convective rolls in foam [Heitkam,
S., & Eckert, K. (2021)].