Two- and three-dimensional behavior of the Rayleigh-Taylor (RT) and Kelvin-Helmholtz (KH) instabilities is examined with a hydrodynamic code: cubic interpolated pseudoparticle. The mushroom structure owing to the KH instability in three dimensions is much smaller than that in two dimensions, and hence the nonlinear growth is faster in three dimensions. The simulation without gravity shows a similar behavior and hence this difference between two and three dimensions does not originate from the RT instability. This difference cannot be explained by linear analysis on the KH instability also.

• Received 23 October 1990

DOI:https://doi.org/10.1103/PhysRevA.44.2756