NMR flow mapping and computational fluid dynamics in Ising-correlated percolation model objects

Abstract

Water flow through quasi two-dimensional percolation model objects was studied with the aid of NMR velocity and acceleration mapping techniques. The model objects were fabricated based on computer generated templates of Ising-correlated percolation clusters of different growth/nucleation ratios for the occupation of the base lattice sites. The same pore networks were used for computational fluid dynamics simulations of hydrodynamic transport properties including hydrodynamic dispersion of tracer particles. The percolation threshold turned out to be lower than that in the uncorrelated case and adopts a minimum if cluster growth is about 100 times more likely than nucleation of the new clusters. The experimental and simulated flow velocity and acceleration maps coincide in great detail. The data have been analysed in terms of histograms and spatial autocorrelation functions. Furthermore, the travelling time of a tracer particle across percolation clusters was evaluated as a function of the Péclet number.