ELFT HÍRADÓ

[Szeminárium koordinátor <sem-admin AT wigner.hun-ren.hu>]

SZFI SeminarLévay, SáraUniversity of Navarra - SZFI, Wigner RCPSecondary 
flows in anisotropic granular matterTuesday, 19 May 2026, 10:00, KFKI Campus, 
Bldg. 1, 2nd floor, Conference RoomWhile granular materials are frequently 
modeled as collections of spheres, most natural and industrial grains are 
inherently anisotropic. This shape anisotropy leads to macroscopic phenomena 
that defy standard granular rheology, such as the spontaneous formation of 
secondary flows and surface heaping observed in particles with high aspect 
ratios.In this seminar, I will present a theoretical and numerical 
investigation into the origin of these complex flow patterns. Using discrete 
element method simulations of elongated particles, we move beyond uniform 
shear to examine the system's linear response to modulated flow 
perturbations. We demonstrate that shape anisotropy generates significant 
normal stress differences, which constitute the physical mechanism driving 
spontaneous transverse vortices. I will discuss how these vortex patterns can 
be predicted analytically and show that the flow structure can invert its 
direction depending on the confinement geometry. Finally, I will connect 
these fundamental results to heaping in split-bottom cells, demonstrating 
that accounting for particle-level anisotropy is essential for predicting 
three-dimensional flow complexity in granular media. Minden érdeklődőt 
szívesen látunk! - Everyone is welcome to attend.Tamás 
Pusztaisem-admin AT wigner.hun-ren.hu