Stream Channel Stability. Appendix L. Stochastic Properties of Turbulent Tractive Forces in Prismatic Channels

The objective of this study is to develop a better understanding of the stochastic structure of the instantaneous boundary shear processes in open channel flows. This report presents new measurements of some stochastic properties of boundary shear stress taken at points spaced over half the wetted perimeter of a smooth open channel, under conditions of essentially constant aspect ratio and Reynolds number. The instantaneous boundary shear stress was measured with hot-film sensors driven by constant-temperature anemometers. The anemometer signals were digitized and analyzed in a high speed computer. The effects of position along the wetted perimeter on the statistical moments and the probabilistic distribution of the instantaneous boundary shear stress are discussed. (Author) Appendix L to AD-A101 385. See also Appendix M, AD-A101 398.