The following picture shows probability densities
of velocity differences as measured on
various scales in a
turbulent Taylor-Couette flow, and the theoretical predictions of a model based on nonextensive statistical mechanics.
There is excellent agreement. Other theoretical models for probability densities in turbulent flows do not yield anything of similar precision.
The measurements were made by Greg Lewis and Harry Swinney
Center for Nonlinear Dynamics, University of Texas at Austin.
More details can be found in the following references:
A recent article in the SCIENCE magazin (23 August 2002) also mentions this.