A benchmark for surface-tension-driven incompressible two-phase flows

TL;DR

This paper introduces a benchmark suite for evaluating surface-tension-driven incompressible two-phase flow simulations, enabling direct comparison of different Volume-of-Fluid methods across popular software tools.

Contribution

It provides a set of standardized benchmarks and open data for quantitatively comparing VoF methods in various simulation platforms.

Findings

Benchmark results highlight differences in accuracy among VoF methods.

Open-source tools like Basilisk perform comparably to commercial software.

The benchmark suite facilitates reproducibility and method validation.

Abstract

The Volume-of-Fluid (VoF) method for simulating incompressible two-phase flows is widespread in academic and commercial simulation software because of its many advantages: a high degree of volume conservation, applicability to unstructured domain discretization (relevant for engineering applications), straightforward parallel implementation with the domain-decomposition and message-passing approach (important for large-scale simulations), and intrinsic handling of strong deformations and topological changes of the fluid interface. However, stable and accurate handling of small-scale capillary flows (dominated by surface tension forces) is still challenging for VoF methods. With many different VoF methods making their way into commercial and open-source software, it becomes increasingly important to compare them quantitatively and directly. For this purpose, we propose a set of simulation benchmarks and use them to directly compare VoF methods available in OpenFOAM, Basilisk, and Ansys Fluent. We use Jupyter notebooks to document and process the benchmark results, making a direct comparison of our results with other two-phase simulation methods very straightforward. The publicly available input data, secondary benchmark data, and post-processing Jupyter notebooks can be re-used by any two-phase flow simulation method that discretizes two-phase Navier-Stokes equations in a one-fluid formulation, which can save a significant amount of person-hours.