Particle partitioning in the Newtonian, Bird-Carreau A and Giesekus fluids. Difference of particle flux ratio minus flow rate ratio as a function of the flow rate ratio for three different confinement ratios: \(\beta =0.1\) (a), \(\beta =0.2\) (b) and \(\beta =0.5\) (c). In each panel, the simulation data for three different suspending fluids are reported with \(\Lambda =1.33\). The lines are fits of the simulations data that are added as a guide for eye. The solid lines have been obtained by considering the data for the Newtonian and the Bird-Carreau A models, whereas the dashed lines refer to the data for Giesekus model.