Nonlinear Stability in the Two-Fluid Model
Abstract
The 1-D Two-Fluid Model (TFM) promises a powerful and computationally cheap platform for simulating multi-fluid flow phenomena. However, runaway Kelvin-Helmholtz instabilities plagued previous approaches, necessitating aphysical regularizations. We demonstrate a novel physics-based approach, using a simple turbulent viscosity model to provide nonlinear stabilization, compatible with inertial coupling. We develop a set of analytical and numerical tools to investigate the resulting dynamics, including turbulent cascades, chaos, and formation of churn or slug flow. Our approach opens up a wide range of new capabilities for the TFM by capturing the Kelvin-Helmholtz instability physically.
Cite
@article{arxiv.2509.04679,
title = {Nonlinear Stability in the Two-Fluid Model},
author = {Alexander López-de-Bertodano and Alejandro Clausse},
journal= {arXiv preprint arXiv:2509.04679},
year = {2025}
}
Comments
26 pages, 25 figures. Software, analysis, and writing by Alexander L\'opez-de-Bertodano. Supervision and review by Alejandro Clausse