Understanding Submerged Granular Avalanches: New Insights into Jamming and Rheology

Recent research has delved into the dynamics of submerged granular avalanches, focusing on jamming transitions and rheological properties. The study, titled "Jamming, Yielding, and Rheology during Submerged Granular Avalanche," was conducted by Zhuan Ge, Teng Man, Kimberly M. Hill, Yujie Wang, and Sergio Andres Galindo-Torres. It employs both experimental and numerical simulation methods, specifically the lattice-Boltzmann method coupled with the discrete element method, to gather detailed stress and deformation data.

The findings reveal a strong correlation between the experimental results and the simulations, confirming the validity of the simulation methods used. A key aspect of the research is the introduction of a new length-scale ratio, denoted as G, which serves as a unified metric for analyzing pressure and shear rate in fluid-granular systems. This metric allows for the categorization of material states into solid-like, creeping, and fluid-like phases based on two critical transition points: G_Y and G_0.

The transition at G_Y indicates a shift from a solid-like state to a creeping state, while G_0 marks the transition to a fluid-like state. The study also discusses the relationship between the friction coefficient and the length-scale ratio, suggesting that established rheological laws apply during transient conditions once G exceeds G_0.

These insights are significant for understanding the behavior of granular materials in various applications, including geophysical processes and industrial operations involving granular flows. The complete study can be accessed through arXiv at arXiv:2408.13730.