title: Experimental Evidence of Helical Flow in Porous Media.
abstract: Helical flow leads to deformation of solute plumes and enhances transverse mixing in porous media. We present experiments in which macroscopic helical flow is created by arranging different materials to obtain an anisotropic macroscopic permeability tensor with spatially variable orientation. The resulting helical flow entails twisting streamlines which cause a significant increase in lateral mass exchange and thus a large enhancement of plume dilution (up to 235%) compared to transport in homogenous media. The setup may be used to effectively mix solutes in parallel streams similarly to static mixers, but in porous media.
authors.affiliation: Center for Applied Geoscience, University of Tübingen, Hölderlinstraße 12, D-72074 Tübingen, Germany.
authors.forename: Yu
authors.initials: Y
authors.lastname: Ye
authors.affiliation: Center for Applied Geoscience, University of Tübingen, Hölderlinstraße 12, D-72074 Tübingen, Germany.|Faculty of Civil, Geo and Environmental Engineering, Technical University of Munich, Arcistraße 21, D-80333 Munich, Germany.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Chiogna
authors.affiliation: Center for Applied Geoscience, University of Tübingen, Hölderlinstraße 12, D-72074 Tübingen, Germany.
authors.forename: Olaf A
authors.initials: OA
authors.lastname: Cirpka
authors.affiliation: Center for Applied Geoscience, University of Tübingen, Hölderlinstraße 12, D-72074 Tübingen, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Grathwohl
authors.affiliation: Center for Applied Geoscience, University of Tübingen, Hölderlinstraße 12, D-72074 Tübingen, Germany.|Department of Environmental Engineering, Technical University of Denmark, Miljøvej Building 115, DK-2800 Lyngby, Denmark.
authors.forename: Massimo
authors.initials: M
authors.lastname: Rolle