  One of the main benchmarks in direct numerical simulations of
three-dimensional turbulence is the Kolmogorov 1941 prediction for third-order
structure functions with homogeneous and isotropic statistics in the
infinite-Reynolds number limit. Previous DNS techniques to obtain isotropic
statistics have relied on time-averaging structure functions in a few
directions over many eddy turnover times, using forcing schemes carefully
constructed to generate isotropic data. Motivated by recent theoretical work
which removes isotropy requirements by spherically averaging structure
functions over all directions, we will present results which supplement
long-time averaging by angle-averaging over up to 73 directions from a single
flow snapshot. The directions are among those natural to a square computational
grid, and are weighted to approximate the spherical average. The averaging
process is cheap, and for the
  Kolmogorov 1941 4/5ths law, reasonable results can be obtained from a single
snapshot of data. This procedure may be used to investigate the isotropic
statistics of any quantity of interest.
