(455e) Molecular Dynamics-Driven Transport Coefficients for Granular Flows: A Perspective

Over the past decade, the closure of constitutive quantities appearing in the continuum description of high-velocity, particle-laden flows has relied heavily on kinetic-theory-based closures. Such descriptions have found considerable success, though do not come without their limitations. For example, the extension of kinetic theory descriptions to non-spherical particles is non-trivial at best. Molecular dynamic (MD) simulations, on the other hand, can be extended in a relatively straightforward manner to accommodate such complexities. Furthermore, because the location of each particle is tracked as a function of time, constitutive quantities can, in principle, be extracted. In practice, however, the identification of the corresponding transport coefficients does not follow easily. In this talk, several complications will be discussed, including the unknown form of the constitutive relation, multiple transport coefficients, clustering instabilities, and Knudsen effects