Collapse of dry and immersed polydisperse granular columns: A unified runout description

We study granular flows with grains of different sizes (i.e., polydispersity) in the granular column collapse configuration, in both dry and immersed systems with a Discrete Element Method - Finite Element Method (DEM-FEM) model. We show that polydispersity has an stronger effect on immersed cases than in dry cases, and propose a unified model that links the runout with the column collapse energy. Our results contribute a novel perspective in the study of immersed polydisperse flows.