$\star$ Instabilities of Rayleigh-Taylor

The instability of Rayleigh-Taylor occurs when a heavy and hot fluid is accelerated in a light fluid. It is the hydrodynamic effect best studied and certainly most significant during the explosion of the supernovæ of the Ia type. It results from the suspension from fuel hot and flaring above fuel not flaring and denser. Prone to this type of instabilities, the small disturbances of surface grow to form bubbles (or mushrooms) which start by floating to fall down in the form of nets (Figure 5.10 ). During the non-linear mode, bubbles of different sizes interact to create a sparkling layer which increases the surface of the flame and thus the rate of reaction.