Why we need experiments at high Reynolds numbers

This brief review focuses on the effect of Reynolds number on turbulence small-scale anisotropy and intermittency, on Lagrangian experiments of fluid and inertial particles and on complex turbulent flows. Although Taylor scale Reynolds numbers of 10 3 (equivalent to turbulence Reynolds number based on the integral scale of 10 5 ) can be achieved in the laboratory, it is argued that there is still a need to do experiments (and computation) at even higher Reynolds numbers to resolve outstanding basic and applied issues in turbulence.