A sharp interface method for compressible liquid-vapor flow with phase transition and surface tension

TL;DR

This paper introduces a sharp interface method for simulating compressible liquid-vapor flows with phase transitions and surface tension, accurately capturing complex interface physics without mixing of phases.

Contribution

It presents a novel multi-phase Riemann solver integrated into a sharp interface approach, handling thermodynamically consistent interface effects in compressible flows.

Findings

Validated with 1D problems showing accurate interface physics

Simulated 3D wobbling droplet demonstrating phase transition effects

Simulated shock-droplet interaction illustrating surface tension influence

Abstract

The numerical approximation of non-isothermal liquid-vapor flow within the compressible regime is a difficult task because complex physical effects at the phase interfaces can govern the global flow behavior. We present a sharp interface approach which treats the interface as a shock-wave like discontinuity. Any mixing of fluid phases is avoided by using the flow solver in the bulk regions only, and a ghost-fluid approach close to the interface. The coupling states for the numerical solution in the bulk regions are determined by the solution of local multi-phase Riemann problems across the interface. The Riemann solution accounts for the relevant physics by enforcing appropriate jump conditions at the phase boundary. A wide variety of interface effects can be handled in a thermodynamically consistent way. This includes surface tension or mass/energy transfer by phase transition. Moreover, the local normal speed of the interface, which is needed to calculate the time evolution of the interface, is given by the Riemann solution. The interface tracking itself is based on a level-set method. The focus in this paper is the description of the multi-phase Riemann solver and its usage within the sharp interface approach. One-dimensional problems are selected to validate the approach. Finally, the three-dimensional simulation of a wobbling droplet and a shock droplet interaction in two dimensions are shown. In both problems phase transition and surface tension determine the global bulk behavior.