A Molecular-Continuum Multiscale Model for Inviscid Liquid-Vapor Flow with Sharp Interfaces

TL;DR

This paper introduces a multiscale model combining continuum Euler equations with molecular simulations to accurately describe liquid-vapor flow with sharp interfaces, avoiding ad-hoc closure relations.

Contribution

It presents a novel multiscale framework integrating molecular dynamics with continuum models for liquid-vapor flow, utilizing neural networks for efficient interface simulation.

Findings

Successfully applied to temperature-dependent regimes previously inaccessible.

Achieved accurate interface dynamics without ad-hoc closure assumptions.

Maintained physical properties with computational efficiency.

Abstract

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.