Special class of self-similar dynamics for Rayleigh-Taylor mixing with variable acceleration

TL;DR

This paper identifies a special class of self-similar solutions in Rayleigh-Taylor mixing driven by variable acceleration, revealing diverse dynamic behaviors and implications for turbulence control in various physical systems.

Contribution

It introduces a new class of self-similar solutions for RT mixing under variable acceleration, expanding understanding beyond constant acceleration models.

Findings

RT mixing dynamics range from super-ballistic to subdiffusive.

Memory of initial conditions persists regardless of acceleration.

Conditions for turbulence realization in RT mixing are identified.

Abstract

Rayleigh-Taylor (RT) mixing has critical importance for a broad range of process in nature and technology, from supernovae and plasma fusion to oil recovery and nano-fabrication. In most instances, RT flows are driven by variable acceleration, whereas the bulk of existing studies have considered only constant and impulsive accelerations. By analyzing symmetries of RT dynamics for certain patterns of variable acceleration, we discover a special class of self-similar solutions and identify their scaling, correlations and spectra. We find that dynamics of RT mixing can vary from super-ballistic to subdiffusive depending on the acceleration and retain memory of deterministic conditions for any acceleration. These rich dynamic properties considerably impact the understanding and control of RT relevant phenomena in fluids, plasmas, materials, and reveal conditions at which turbulence can be realized in RT mixing.