Anisotropy and scaling corrections in turbulence.

Two parametrizations for second order velocity moments, the Batchelor parametrization for the r-space structure function and a common parametrization for the energy spectrum, E(p) ∝ p exp(−p/pd), are examined and compared. In particular, we investigate corrections to the local scaling exponents induced by finite size effects. The behavior of local r– and p–space exponents differs dramatically. The Batchelor type parametrization leads to energy pileups in p-space at the ends of the ISR. These bottleneck effects result in an extended r-space scaling range, comparable to experimental ones for the same Taylor-Reynolds number Reλ. Shear effects are discussed in terms of (global) apparent scaling correction δζ to classical scaling. The scaling properties of δζ(Reλ) differ not only among the parametrizations considered, but also among r– and p–space for a given parametrization. The difference can be traced back to the subtleties of the crossovers in the velocity moments. Our observations emphasize the need for more experimental information on crossovers between different subranges.