Abstract
Three-dimensional measurements of open-channel flows were conducted by making use of two sets of laser Doppler anemometers. One is able to measure the u-v components, and the other is able to measure the u-w components. The Reynolds stress (-vw) could be first measured with high accuracy. The streamwise velocities which were measured by u-v measurement and u-w measurements were in a good agreement with each other. The third moments of the velocity fluctuations were agree well with the results of DNS (Direct Numerical Simulation). A new empirical formula, involving the van Driest damping function, expresses the spanwise turbulence intensity in the inner region.
