Porous media are very common in nature and represent important materials with several applications in engineering, physics and chemistry. Technological process involving porous materials include oil exploration and production, heterogeneous catalysis, identification and exploration of aquifers, pollution dispersion, and chromatography, among others.
A recent article by reasearchers from UFC, ETH-Zurich and Lisbon University shed light on understanding particle-laden flow by means of an analog electrical network model. The report appeared last December in the prestigious journal Physical Review Letters [http://dx.doi.org/10.1103/PhysRevLett.117.275702 (Link to new site)].
Flow in porous media is traditionally investigated in terms of a disordered pore network with fixed structure through which a given fluid is transported. By itself, this physical problem already represents a relevant scientific and technological challenge. The situation becomes even more complicated when the pore space is
deformable or has to adapt in response to interactions with the flowing fluid. For example, if this fluid erodes and deposits material, the clogging and reopening of channels depends on the evolution of local conditions.
A novel dynamic phase in electrical networks is reported, in which current channels perpetually change in time. This occurs when the individual elements of the network are fuse-antifuse devices, namely, become insulators within a certain finite interval of local applied voltages. The conditions under which this exotic situation appears are determined by establishing a phase diagram as a function of the applied field and the size of the insulating window. Besides its obvious application as a versatile electronic device, due to its rich variety of behaviors, this network model provides a possible description for particle-laden flow through porous media leading to dynamical clogging and reopening of the local channels in the pore space.
The full reference of the paper is:
Itinerant Conductance in Fuse-Antifuse Networks
Cesar I. N. Sampaio Filho, André A. Moreira, Nuno A. M. Araújo, José S. Andrade, Jr, and Hans J. Herrmann
Phys. Rev. Lett. 117, 275702 (2016)