Low Reynolds Number Effects on the Inner Region of a Turbulent Boundary Layer

Low-Reynolds-number effects on the inner region of a zero pressure gradient turbulent boundary layer have been investigated using a two-component laser-Doppler velocimetry (LDV) system. The momentum thickness Reynolds number Rθ is in the range 400 to 1320. The wall shear stress is determined from the mean velocity gradient close to the wall, allowing scaling on wall variables to be examined unambiguously. The results indicate that, for the present Rθ range, this scaling is not appropriate.