Localized jammed clusters persist in shear-thickening suspension subjected to swirling excitation

This study reports a novel dynamic in shear-thickening suspensions with a free surface under bottom shear, revealing localized, persistent jammed clusters (bumps in the image). We clarify the essential role of shear-thickening properties and the effect of suspension depth, showing that at small depth this heterogeneous state could occur below the minimum density of discontinuous shear-thickening. Moreover, our findings emphasize the critical role of free surfaces in cluster growth. This advances our understanding of the evolution of heterogeneity associated with shear-thickened states.