A conservative level set method for liquid-gas flows with application in liquid jet atomisation

TL;DR

This paper introduces a conservative level set method combined with a volume of fluid approach for accurately modeling two-phase liquid-gas flows, particularly in liquid jet atomisation, with low mass conservation errors and good agreement with existing methods.

Contribution

It presents a novel coupling of a conservative level set method with a volume of fluid approach and a new re-initialisation technique for improved interface tracking in two-phase flows.

Findings

Accurate interface capturing with low mass conservation errors.

Good agreement with classical test results and direct numerical simulations.

Effective modeling of primary break-up in turbulent liquid jets.

Abstract

In this paper, a methodology for modelling two-phase flows based on a conservative level set method in the framework of finite volume method is presented. The novelty of the interface capturing method used here lies on the advection of level set which is solved with a WENO scheme and is corrected with a novel re-initialisation method for retaining its signed distance function character. The coupling with the volume of fluid method is done with a simple algebraic approach and with the new algorithm the accumulated mass conservation errors remain reasonably low. The paper presents a unique coupling between the level set method and the Eulerian-Lagrangian-Spray-Atomisation approach for modelling spray dispersion in liquid atomisation systems. The method is shown to have good accuracy providing similar results to other numerical codes for the classical tests presented. Preliminary results are also shown for three-dimensional simulations of the primary break-up of a turbulent liquid jet obtaining results comparable to direct numerical simulations. Consequently, the coupled method can be used for simulating various two-phase flow applications offering an accurate representation of the interface dynamics.