On the three-dimensional Rayleigh–Taylor instability

TLDR

The three-dimensional Rayleigh–Taylor instability is investigated using a lattice Boltzmann scheme for nearly incompressible multiphase flow. The study investigates the evolution of the three-dimensional interface structure in Rayleigh–Taylor instability. The authors employ a lattice Boltzmann multiphase flow solver and parallel computing to simulate the instability at high resolution. The simulations reveal that, besides bubble and spike fronts, a saddle point emerges as a key interface landmark, with heavy‑fluid roll‑ups forming at both the spike tip and saddle point and a secondary horizontal instability further entangling the interface.

Abstract

The three-dimensional Rayleigh–Taylor instability is studied using a lattice Boltzmann scheme for multiphase flow in the nearly incompressible limit. This study focuses on the evolution of the three-dimensional structure of the interface. In addition to the bubble and spike fronts, a saddle point is found to be another important landmark on the interface. Two layers of heavy-fluid roll-ups, one at the spike tip and the other at the saddle point, were observed. The secondary instability in the horizontal planes entangles the already complicated structure of the interface. Parallel computations are utilized to accommodate the massive computational requirements of the simulations.