English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

We present a numerical simulation study of advective-diffusive scalartransport in three-dimensional high-contrast discontinuous permeability fields,generated with a truncated pluri-Gaussian geostatistical approach. A range ofpermeability contrasts, correlation lengths, and P\'eclet numbers are studiedto characterise the transition to non-Fickian transport behaviour. This istriggered by high permeability contrasts between different zones and isenhanced by the presence of connected higher permeability channels, which arecharacterised by high advective flow velocities. In this case, the overalltransport behaviour deviate from the macroscopic advection-dispersion modelbased on a Fickian analogy. The numerical experiments are run with an Eulerianapproach using a novel unified numerical framework based on the finite-volumelibrary \of, for i) generating random pluri-Gaussian porous media, ii) solvingthe steady state Darcy-scale flow, iii) solving the advection diffusionequation, iv) computing post-processing quantities such as first orderstatistics, spatial probability density functions and breakthrough curves. Weidentify a hierarchy of non-Fickian transport triggering factors, the strengthof permebility contrast being the pivotal driver. The P\'eclet number and thecharacteristic length at which facies transitions are observed as secondaryfactors. Transport remains Fickian when the facies conductivities differ by upto one order of magnitude. Greater permeability contrasts act strengthen theemergence of fast flow channels leading to non-Fickian transport.

Emergence of non-Fickian transport in truncated pluri-Gaussian permeability fields