Rayleigh–Taylor instability

A fluid-interface instability in which a denser fluid accelerates into a lighter one, amplifying small disturbances into descending fingers and rising bubbles.

Atwood number: A dimensionless measure of density contrast between two fluids, defined as their difference divided by their sum. It sets the strength of the instability for a given acceleration.
Fluid interface: A boundary separating fluids with different compositions, densities, or other properties. The growing disturbance begins as a deformation of this boundary.
Supernova remnant: The expanding debris and shocked surrounding material left after a stellar explosion. Rayleigh–Taylor mixing helps distribute stellar ejecta through the remnant.
Saffman–Taylor instability: A pattern-forming instability in which a less viscous fluid displaces a more viscous one in a narrow gap or porous medium. Its branching fingers resemble Rayleigh–Taylor structures but arise from viscosity contrast.
Linear stability analysis: A method that tests how small disturbances evolve by linearizing a system's governing equations. It predicts which interface wavelengths grow and how quickly.
Buoyancy: A force on an immersed body or fluid element arising from pressure differences in a gravitational or accelerated field. The density contrast turns acceleration into an overturning force.
Inertial confinement fusion: A fusion approach that compresses and heats a fuel capsule with intense, rapidly delivered energy. Interface growth can mix capsule material into the fuel and reduce compression.
Boussinesq approximation: A fluid-model simplification that treats density as constant except where it generates buoyancy. It provides a tractable model for many small-density-contrast experiments.
Richtmyer–Meshkov instability: An interface instability caused when an impulsive acceleration deposits vorticity across a density boundary. Unlike sustained acceleration here, an impulsive shock initiates its growth.
Navier–Stokes equations: The equations governing momentum and mass conservation in fluid motion. They describe how viscosity and inertia shape the unstable flow.

Linked from 11 pages