Related Experiment Video
Updated: Jun 23, 2026

Visually Based Characterization of the Incipient Particle Motion in Regular Substrates: From Laminar to Turbulent Conditions
Published on: February 22, 2018
Avalanches and non-Gaussian fluctuations of the global velocity of imbibition fronts
Ramon Planet1, Stéphane Santucci, Jordi Ortín
1Departament d'Estructura i Constituents de la Matèria, Universitat de Barcelona, Martí i Franquès 1, E-08028 Barcelona, Spain.
Abstract:
We present an experimental study of the global velocity V(t) of a viscous fluid interface during forced-flow imbibition in a disordered medium. Our high resolution setup shows that the fronts display an intermittent behavior signature of a burstlike dynamics, with power-law distributed avalanches. When measured at scales comparable to the correlation length, velocity fluctuations follow an asymmetric non-Gaussian distribution, whose skewness increases with decreasing measuring window and/or injection flow rate, offering the effective number of degrees of freedom probed in our experiment.
Related Concept Videos
Deriving the Speed of Sound in a Liquid
The speed of sound in fluids can be derived by considering a mechanical wave propagating...
Pressure Variation in a Fluid at Rest
When measuring pressure at two different levels within the fluid, the difference in pressure...
Rapidly Varying Flow
Viscosity
The SI unit of viscosity is...
Velocity and Acceleration in Steady and Unsteady Flow
The acceleration can be generalized to any point in the flow, and expressed as components along three perpendicular directions, representing changes in velocity over time.
Accelerating Fluids
The motion of the liquid within this infinitesimal cylinder is considered to obtain the pressure difference. Three vertical forces act on this liquid:

