Granular Matter: How Structure Determines Response Far From Equilibrium

• Applicant: Dr. Wolf Till Kranz
• Subject Area: Statistical Physics, Nonlinear Dynamics, Complex Systems, Soft and Fluid Matter, Biological Physics
• Term: from 2017 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 335058789

Granular flows, be it natural avalanches or industrial chute flows, occur at considerable number densities of the constituting particles. Regarding granular matter from a statistical physics point of view, it is natural to assume that the structure of the many-particle system and its response to external perturbations is closely linked. In equilibrium fluids, this link is universally provided by fluctuation dissipation theorems. Granular flows are essentially far from equilibrium due to the dissipative collisional interactions. Consequentially, the equilibrium theorems due not apply. The aim of this project is to derive and develop kinetic theories for the Response of granular matter at densities between the glass transition density and the random close packing density. With these theories at hand it will be possible to determine the structure of granular flows from their response behaviour and, vice versa, predict the response from structural information. The predictions of the theories shall be validated against experiments and shall be implemented in numerical models of fluid dynamics in the form of constitutive equations.

• DFG Programme: Research Grants