Average Velocity Distribution of Turbulent Pipe Flow with Emphasis on the Viscous Sublayer

A comprehensive experimental investigation is presented of the average velocity distribution of fully developed, smooth turbulent flows through straight pipes of circular cross section with special regard to the distribution within the viscous sublayer, including data at zero distance from the wall. The measurements seem to remove uncertainties and discrepancies inherent from earlier investigations. Current concepts of the universal velocity distribution are confirmed and verified.