Intermittency and local dissipation scales under strong mean shear

We experimentally probe the local dissipation scale distribution Q(eta) and temporal fluctuations of the turbulent kinetic energy dissipation rate epsilon in the strongly anisotropic flow past a backward facing step. A shift in Q(eta) and corresponding reduction in the relative intermittency of epsilon is observed with increasing mean shear S. We offer physical arguments to elucidate the role of strong shear on the small-scale structure. A local mean-shear dissipation Reynolds number, Re<emph type="20">S equivalent to <<epsilon >>/(S2 nu), is proposed that may define a family of universal small-scale structures of turbulence.