  The dynamics of compressible liquid-vapor flow depends sensitively on the
microscale behavior at the phase boundary. We consider a sharp-interface
approach, and propose a multiscale model to describe liquid-vapor flow
accurately, without imposing ad-hoc closure relations on the continuum scale.
The multiscale model combines the Euler equations on the continuum scale with
molecular-scale particle simulations that govern the interface motion. We rely
on an interface-preserving moving mesh finite volume method to discretize the
continuum-scale sharp-interface flow in a conservative manner. Computational
efficiency, while preserving physical properties, is achieved by a surrogate
solver for the interface dynamics based on constraint-aware neural networks.
The multiscale model is presented in its general form, and applied to regimes
of temperature-dependent liquid-vapor flow which have not been accessible
before.
