Speed of free convective fingering in porous media

Scaling of convective mixing in porous media.

Convective mixing in porous media is triggered by a Rayleigh-Bénard-type hydrodynamic instability as a result of an unstable density stratification of fluids. While convective mixing has been studied extensively, the fundamental behavior of the dissolution flux and its dependence on the system parameters are not yet well understood. Here, we show that the dissolution flux and the rate of fluid ...

Hysteresis models and gravity fingering in porous media

We study flow problems in unsaturated porous media. Our main interest is the gravity driven penetration of a dry material, a situation in which fingering effects can be observed experimentally and numerically. The flow is described by either a Richards or a two-phase model. The important modelling aspect regards the capillary pressure relation which can include static hysteresis and dynamic cor...

Modelling of Convective Heat Transfer in Porous Media

This thesis details the process taken for the computational modelling of convective heat transfer in porous media with the objective of improving the accuracy of porous continuum models. CFD simulations were performed to predict convective heat transfer resulting from forced flow through highly conductive porous blocks. For the pore-level predictions, an idealized geometric model for spherical-...

Convective instabilities of chemical fronts in close-packed porous media

Spatiotemporal pattern formation in the autocatalytic chlorite–tetrathionate reaction is studied experimentally in porous media where heterogeneities are introduced as glass beads packed in a monolayer. From initially vertical planar chemical fronts in a vertical slab, asymmetric convective structures with stable geometry evolve which propagate horizontally with constant speed. The single conve...

Spatiotemporal behavior of convective Turing patterns in porous media