Overview

• University of Sydney scientists built an X-ray rheography platform, DynamiX, that images moving granular interiors without halting the flow.
• In a conveyor-driven bulldozing experiment with 3 mm glass beads, faint surface ripples were tied to sideways currents beneath the pile.
• The study delivers the first direct experimental evidence of secondary flows in granular materials, published in Nature Communications.
• Researchers say accounting for these hidden motions could sharpen models of landslides, avalanches, and industrial powder handling.
• The current setup measures velocity chiefly along one direction and uses idealized beads, with planned work to identify drivers and test other materials.