  Understanding the dynamics of phase boundaries in fluids requires
quantitative knowledge about the microscale processes at the interface. We
consider the sharp-interface motion of compressible two-component flow, and
propose a heterogeneous multiscale method (HMM) to describe the flow fields
accurately. The multiscale approach combines a hyperbolic system of balance
laws on the continuum scale with molecular-dynamics simulations on the
microscale level. Notably, the multiscale approach is necessary to compute the
interface dynamics because there is -- at present -- no closed continuum-scale
model. The basic HMM relies on a moving-mesh finite-volume method, and has been
introduced recently for compressible one-component flow with phase transitions
in [Magiera and Rohde, JCP. 469 (2022)]. To overcome the numerical complexity
of the molecular-dynamics microscale model a deep neural network is employed as
an efficient surrogate model. The entire approach is finally applied to
simulate droplet dynamics for argon-methane mixtures in several
space-dimensions. Up to our knowledge such compressible two-phase dynamics
accounting for microscale phase-change transfer rates have not yet been
computed.
