Interfaces and Mixing in Fluids, Plasmas, and Materials

Coordinators: Snezhana I. Abarzhi, William A. Goddard III, and Katepalli Sreenivasan

Interfaces and interfacial mixing and their non-equilibrium dynamics and kinetics govern a broad range of processes in nature and technology, in fluids, plasmas and materials, in turbulent and in coherent states, from celestial to atomic events, under conditions of high and low energy density. Examples include supernovae and fusion, planetary convection and solar flares, fluid instabilities and turbulent mixing, reconnection events in quantum fluids and in conducting plasmas, materials processing and electro-catalysis, purification of water and nano-fabrication. In these realistic environments, flow fields change sharply and rapidly, accelerations are strong, energy releases are high, relaxations are weak, and phases of matter are well pronounced. Interfaces and interfacial mixing couple micro- to macro scales, and are challenging to study in theory, experiments and simulations, in the kinetic and in continuous limits.

Interfaces are phase boundaries broadly defined. These can be interfaces between two distinct matters or between the same matters with distinct thermodynamics and electro-dynamic properties. The matter (fluid, plasma, material) can experience a phase transition, be out of thermodynamic equilibrium, and undergo a change in chemical composition. Phase boundaries can appear microscopically vanishing and yet possess observable macroscopic interfacial fluxes (of, e.g., mass, heat, electric charge). They can form when two matters meet, and when one matter gains non-uniform structures. At interfaces, properties of matter experience dramatic changes at minuscule scales, and microscopic interfacial transports define the macroscopic fields in the bulk. In all these circumstances, an interface is a place where balances are achieved; as such, the interface dynamics is eligible to first principle theoretical considerations.

At this conference, we intend to explore group theory based and other methodologies for solving interface dynamics and conservation laws far from equilibrium. Groups and representations are powerful methods defining how symmetry of a system influences solutions of equations governing that system. In synergy with experiments and simulations, we aim to associate attributes of analytical and numerical solutions with physical observables at continuous and molecular scales. Through guidance from the observations, we target to approach non-equilibrium dynamics and kinetics of interfaces and interfacial mixing at levels of detail and abstraction not achieved before and to capture their fundamentals in vastly distinct physical regimes. We examine, e.g., whether in fluids unstable interfaces can lead to turbulence and its anomalous scaling, whether in plasmas the interface topology and transports are tightly linked to volumetric fields, whether in multi-phase materials the energy can scatter beyond conventional diffusion and/or can be trapped at atomic scales.

This exploration conference brings together researchers from various areas of science, mathematics and engineering, including theoretical physics, plasma physics, fluid dynamics, astrophysics, and materials science. Researchers at advanced and earlier stages of their career are invited to participate.