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 similar to a(i)Agt(2) for a constant acceleration and as a power law t(theta i) for an impulsive acceleration g=U delta(t). The growth coefficients alpha(i) and exponents theta(i) 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. [S1070-664X(99)90405-6].