Self-similar Rayleigh-Taylor mixing with accelerations varying in time and space.

As a ubiquitous paradigm of instabilities and mixing that occur in instances as diverse as supernovae, plasma fusion, oil recovery, and nanofabrication, the Rayleigh-Taylor (RT) problem is rightly regarded as important. The acceleration of the fluid medium in these instances often depends on time and space, whereas most past studies assume it to be constant or impulsive. Here, we analyze the symmetries of RT mixing for variable accelerations and obtain the scaling of correlations and spectra for classes of self-similar dynamics.

Erratum: Whittle maximum likelihood estimate of spectral properties of Rayleigh-Taylor interfacial mixing using hot-wire anemometry experimental data [Phys. Rev. E 102, 053107 (2020)].

This corrects the article DOI: 10.1103/PhysRevE.102.

Supernovae and the Arrow of Time.

Supernovae are explosions of stars and are a central problem in astrophysics. Rayleigh-Taylor (RT) and Richtmyer-Meshkov (RM) instabilities develop during the star's explosion and lead to intense interfacial RT/RM mixing of the star materials. We handle the mathematical challenges of the RT/RM problem based on the group theory approach.

Whittle maximum likelihood estimate of spectral properties of Rayleigh-Taylor interfacial mixing using hot-wire anemometry experimental data.

Investigating the power density spectrum of fluctuations in Rayleigh-Taylor (RT) interfacial mixing is a means of studying characteristic length, timescales, anisotropies, and anomalous processes. Guided by group theory, analyzing the invariance-based properties of the fluctuations, our paper examines raw time series from hot-wire anemometry measurements in the experiment by Akula et al. [J.

Supernova, nuclear synthesis, fluid instabilities, and interfacial mixing.

Supernovae and their remnants are a central problem in astrophysics due to their role in the stellar evolution and nuclear synthesis. A supernova's explosion is driven by a blast wave causing the development of Rayleigh-Taylor and Richtmyer-Meshkov instabilities and leading to intensive interfacial mixing of materials of a progenitor star. Rayleigh-Taylor and Richtmyer-Meshkov mixing breaks spherical symmetry of a star and provides conditions for synthesis of heavy mass elements in addition to light mass elements synthesized in the star before its explosion.

Interface dynamics: Mechanisms of stabilization and destabilization and structure of flow fields.

Interfacial mixing and transport are nonequilibrium processes coupling kinetic to macroscopic scales. They occur in fluids, plasmas, and materials over celestial events to atoms. Grasping their fundamentals can advance a broad range of disciplines in science, mathematics, and engineering.

Acceleration and turbulence in Rayleigh-Taylor mixing.

Past decades have significantly advanced our ability to probe turbulent mixing in Rayleigh-Taylor flows, in both experiments and simulations. Yet, our basic understanding remains elusive and requires better basis. For instance, observations do not substantiate the rudimentary dimensional arguments to the same degree of certainty as in classical three-dimensional turbulence.

What is certain and what is not so certain in our knowledge of Rayleigh-Taylor mixing?

Past decades significantly advanced our understanding of Rayleigh-Taylor (RT) mixing. We briefly review recent theoretical results and numerical modelling approaches and compare them with state-of-the-art experiments focusing the reader's attention on qualitative properties of RT mixing.

Review of theoretical modelling approaches of Rayleigh-Taylor instabilities and turbulent mixing.

We review the theoretical developments in the field of Rayleigh-Taylor instabilities and turbulent mixing, discuss what is known and what is not known about the phenomenon, and outline the features of similarity of the turbulent mixing process. Based on the physical intuition and on the results of rigorous theoretical studies, we put forward some new ideas on how to grasp the essentials of the mixing process and consider the influence of momentum transport on the invariants and on scaling and statistical properties of the unsteady turbulent mixing.

High-performance holographic technologies for fluid-dynamics experiments.

Modern technologies offer new opportunities for experimentalists in a variety of research areas of fluid dynamics. Improvements are now possible in the state-of-the-art in precision, dynamic range, reproducibility, motion-control accuracy, data-acquisition rate and information capacity. These improvements are required for understanding complex turbulent flows under realistic conditions, and for allowing unambiguous comparisons to be made with new theoretical approaches and large-scale numerical simulations.