Shear-thinning, Coulomb friction and grain collisions in debris-flow waterfalls: Applications of a 3D phase mixture model with a single calibration parameter and a complex 4-way coupled resolved CFD-DEM approach

Shear-thinning is a common flow-feature of fine sediment suspensions. Mixed with gravel, Coulomb friction drives the energy dissipation between small grains while collisions become more and important larger grains. The interaction flow local geometries channel can enforce each these three key features, making design analysis sections obstacles highly back-coupled system. This paper addresses numerical simulation debris material under extreme conditions at planned protection measures. Mixtures grain sizes are modelled single calibration parameter using 3D CFD phase mixture software debrisInterMixing compared laboratory experiments. To further investigate scaling results, coupled code YADE debrisInterMixingLP applied accounting for 4-way coupling to coarse boulders front resolved CFD-DEM, reaching beyond possibilities