Modeling Granular Segregation: Insights from Four Decades of Research

In this review, we introduce granular materials as a condensed matter system and briefly discuss their general properties. We then focus on particle segregation in rapid, dense granular flows, a phenomenon that occurs more readily in granular materials than in other condensed matter systems. Our primary emphasis is on the development of continuum models to describe segregation in these systems. Over the years, numerous approaches have been proposed, each offering different perspectives on how to construct such models. Rather than providing an exhaustive review of any single approach, we compare and contrast various modeling strategies, highlighting their commonalities and respective advantages. By doing so, we aim to establish a clearer connection between different approaches, facilitating closer comparisons and potential synergies between them. We believe that bridging these approaches is essential for advancing our understanding and improving predictive capabilities in granular segregation modeling in the future.