Upstream history and apparent stress in turbulent boundary layers

May 1966Also issued as: Massachusetts Institute of Technology. Dept. of Mechanical Engineering. Thesis. 1966. Ph.DIncludes bibliographical references (leaves 43-45, second group)A comprehensive experimental and analytical study specifically designed to investigate upstream history and apparent stresses in incompressible, two-dimensional, turbulent boundary layers has been conducted. Hot-wire measurements of turbulent shear stress and longitudinal turbulence intensity, as well as velocity profiles and wall shear stress measurements, were made for six different pressure distributions. It was found that the turbulent shear stress is dependent upon the upstream history of the flow and not a unique function of the local velocity profile. A simple equation for the dissipation integral . . . with a constant K was found to represent the data well. This expression was used with the mean-flow energy integral equation to obtain a practical method for predicting turbulent boundary layer behavior which accounts for upstream history. The predictions made with this method for the six pressure distributions of this study and for others extracted from the literature agreed well with the experimental data.Research was carried out under the Bureau of Ships General Hydromechanics Research Program , administered by the David Taylor Model Basin Contract S-R009 01 01 Nonr 184(91