This article focuses on the characterization of slug-flow hydrodynamics in two sizes of tubular membrane re diameters (6 and 15 mm) to quantify the main mechanical phenomena involved iii the limitation of particle fouling during cross-flow filtration of suspensions. By using a conductance probe technique, the flow structure was accurately identified for two geometries, nod noticeable differences tt ere observed in terms of void fractions, velocities and lengths of Taylor bubbles, and liquid slugs. This characterization allowed some data to be theoretically estimated (wall shear stress, "falling" film velocity: film thickness) thanks to the application of a phenomenological model initially developed for oil pipes. The results obtained in a 15-mm tube showed that the ultrafiltration flux improvement experimentally achieved with bentonite and yeast suspensions, was partly due to the increase in the wall shear stress, induced by continuous gas sparging inside the tubular filtration module. Other hydrodynamic phenomena linked to the quasi-periodic succession of Taylor bubbles and liquid slugs were also involved in the control of the particle entrainment: intermittency frequency reversal of the wall shear stress instantaneous pressure variations in the long bubble wake with a higher level of turbulence, and an enhanced local mixing.