Reynolds number effects on the fluctuating velocity distribution in wall-bounded shear layers

The stream wise turbulence intensity and wall-shear stress fluctuations of zero pressure gradient (ZPG) turbulent boundary layers are investigated for seven Reynolds numbers based on the momentum thickness in the range of 1009 <= Re-theta <= 4070 by particle-image velocimetry (PIV) and micro-particle tracking velocimetry (mu-PTV) at a spatial resolution up to 0.06-0.23 wall units such that the viscous sublayer is well resolved. The statistics evidence good agreement with direct numerical simulations (DNS) and experimental results from the literature. The experimental results show the stream wise turbulence intensity and wall-shear stress fluctuation to grow at increasing Reynolds numbers.