  Shear cell simulations and experiments of weakly wetted particles (a few
volume percent liquid binders) are compared, with the goal to understand their
flow rheology. Application examples are cores for metal casting by core
shooting made of sand and liquid binding materials. The experiments are carried
out with a Couette-like rotating viscometer. The weakly wetted granular
materials are made of quartz sand and small amounts of Newtonian liquids. For
comparison, experiments on dry sand are also performed with a modified
configuration of the viscometer. The numerical model involves spherical,
monodisperse particles with contact forces and a simple liquid bridge model for
individual capillary bridges between two particles. Different liquid content
and properties lead to different flow rheology when measuring the shear
stress-strain relations. In the experiments of the weakly wetted granular
material, the apparent shear viscosity $\eta_g$ scales inversely proportional
to the inertial number $I$, for all shear rates. On the contrary, in the dry
case, an intermediate scaling regime inversely quadratic in $I$ is observed for
moderate shear rates. In the simulations, both scaling regimes are found for
dry and wet granular material as well.
