Mardi 22 juillet 2025 à 11h ; salle 259 - IUSTI
I present a particle-scale simulation method for non-Brownian suspension flows at low Reynolds number, based on the Fictitious Domain Method and supplemented by sub-grid lubrication corrections. First, I study adhesive frictional suspensions by varying adhesion strength and volume fraction. At low volume fraction, wall depletion and shear banding arise, but at higher concentrations, viscosity depends on both volume fraction and shear stress. This behavior fits within the jamming framework provided that the jamming volume fraction now depends on the dimensionless shear stress that involves the adhesive force, separating flowing and jammed states. Next, I investigate shear-induced migration in pressure-driven flows, where particles accumulate at the channel center, forming a plug where local volume fraction exceeds the homogeneous shear jamming threshold. Stresses satisfy the expected balances, validating the method; comparison with a modified Suspension Balance Model highlights the limitations of the latter. Finally, using 2D DEM simulations, I study the emergence of rigid clusters in shear-thickened states, identifying a critical volume fraction and stress-dependent rigidity transition.