  We have investigated the sliding of droplets made of solutions of Xanthan, a
stiff rodlike polysaccharide exhibiting a non-newtonian behavior, notably
characterized by a shear-rate dependence of the viscosity. These experimental
results are quantitatively compared with those of newtonian fluids (water). The
impact of the non-newtonian behavior on the sliding process was shown through
the relation between the average dimensionless velocity (i.e. the Capillary
number) and the dimensionless volume forces (i.e. the Bond number). To this
aim, it is needed to define operative strategies to compute the Capillary
number for the shear thinning fluids and compare with the corresponding
newtonian case. Results from experiments were complemented with lattice
Boltzmann numerical simulations of sliding droplets, aimed to disentangle the
influence that non-newtonian flow properties have on the sliding.
