  We present the results of a numerical investigation of three-dimensional
decaying turbulence with statistically homogeneous and anisotropic initial
conditions. We show that at large times, in the inertial range of scales: (i)
isotropic velocity fluctuations decay self-similarly at an algebraic rate which
can be obtained by dimensional arguments; (ii) the ratio of anisotropic to
isotropic fluctuations of a given intensity falls off in time as a power law,
with an exponent approximately independent of the strength of the fluctuation;
(iii) the decay of anisotropic fluctuations is not self-similar, their
statistics becoming more and more intermittent as time elapses. We also
investigate the early stages of the decay. The different short-time behavior
observed in two experiments differing by the phase organization of their
initial conditions gives a new hunch on the degree of universality of
small-scale turbulence statistics, i.e. its independence of the conditions at
large scales.
