Preasymptotic hydrodynamic dispersion as a quantitative probe of permeability.

We interpret a generalized short-time expansion of stochastic hydrodynamic dispersion dynamics in the case of small Reynolds number flow through macroscopically homogenous permeable porous media to directly determine hydrodynamic permeability. The approach allows determination of hydrodynamic permeability from pulsed field gradient spin-echo nuclear magnetic resonance measurement of the short-time effective hydrodynamic dispersion coefficient. The analytical expansion of asymptotic dynamics agrees with experimental NMR data and lattice Boltzmann simulation of hydrodynamic dispersion in consolidated random sphere pack media.

NMR measurement of the transport dynamics of colloidal particles in an open cell polymer foam porous media.

The transport of model hard sphere core shell colloidal particles under flow through a random open-cell solid polymer foam is studied using nuclear magnetic resonance. Unique data on the scale dependent dynamics of the colloidal particle and suspending fluid phase are obtained using spectral chemical resolution. The dynamics of each phase are shown to differ from one another dependent on the displacement length and time scale of the measurement.

Dynamic length-scale characterization and nonequilibrium statistical mechanics of transport in open-cell foams.

Nuclear magnetic resonance measurements of scale dependent dynamics in a random solid open-cell foam reveal a characteristic length scale for transport processes in this novel type of porous medium. These measurements and lattice Boltzmann simulations for a model foam structure indicate dynamical behavior analogous to lower porosity consolidated granular porous media, despite extremely high porosity in solid cellular foams. Scaling by the measured characteristic length collapses data for different foam structures as well as consolidated granular media.