Nonlinear evolution of the Rayleigh–Taylor and Richtmyer–Meshkov instabilities

Scaled experiments on the nonlinear Rayleigh–Taylor (RT) and Richtmyer–Meshkov (RM) instabilities are described for two limiting conditions. First, at high Reynolds number, the mixing layer is found to grow self-similarly ∼αiAgt2 for a constant acceleration and as a power law tθi for an impulsive acceleration g=Uδ(t). The growth coefficients αi and exponents θi are measured over a comprehensive range of Atwood number A. Second, with non-Newtonian materials, the critical wavelength and amplitude for RT instability associated with the shear modulus and tensile yield of the material is observed over a variety of conditions. The results are applied to naturally occurring supernova explosions and volcanic islands.