Validation and application of the lattice Boltzmann algorithm for a turbulent immiscible Rayleigh-Taylor system

TL;DR

This paper develops and validates a multicomponent lattice Boltzmann model for simulating 2D immiscible Rayleigh-Taylor turbulence, demonstrating accurate interface handling and energy analysis, paving the way for 3D applications.

Contribution

The paper introduces a GPU-accelerated multicomponent lattice Boltzmann model for immiscible Rayleigh-Taylor turbulence with validated accuracy and detailed energy analysis.

Findings

Accurate interface representation in turbulent regimes

Energy balance analysis including interface effects

Comparison of statistical properties for miscible and immiscible flows

Abstract

We develop a multicomponent lattice Boltzmann (LB) model for the 2D Rayleigh--Taylor turbulence with a Shan-Chen pseudopotential implemented on GPUs. In the immiscible case this method is able to accurately overcome the inherent numerical complexity caused by the complicated structure of the interface that appears in the fully developed turbulent regime. Accuracy of the LB model is tested both for early and late stages of instability. For the developed turbulent motion we analyze the balance between different terms describing variations of the kinetic and potential energies. Then, we analyze the role of interface in the energy balance, and also the effects of the vorticity induced by the interface in the energy dissipation. Statistical properties are compared for miscible and immiscible flows. Our results can also be considered as a first validation step to extend the application of LB model to 3D immiscible Rayleigh-Taylor turbulence.