Anomalous Scaling - Square SR

Pressure-dependent scaling scenarios in experiments of spontaneous im

R. Planet, M. Pradas, A. Hernandez-Machado and J. Ortin

The scaling properties of the rough liquid--air interface formed in the spontaneous imbibition of a viscous liquid by a model porous medium are found to be very sensitive to the magnitude of the pressure difference applied at the liquid inlet. Interface fluctuations change from obeying intrinsic anomalous scaling at large negative pressure differences, to being superrough with the same dynamic exponent Z ~ 3 at less negative pressure differences, to finally obey ordinary Family-Vicsek scaling with Z ~ 2 at large positive pressure differences. This rich scenario reflects the relative importance on different length scales of capillary and permeability disorder, and the role of surface tension and viscous pressure in damping interface fluctuations.

[Phys. Rev. E (submitted)]