Determination of the Slope and Intercept of the Universal Velocity Profile from Pressure Loss Measurements

摘要

A method is demonstrated for determination of the slope and intercept of the universal velocity distribution law for flow past roughened surfaces without the need for measurement of the velocity profile. The slope is shown to vary with the nature of the roughened surface and in some cases to deviate considerably from that for turbulent flow past smooth walls. It is further shown that the intercept, commonly known as the roughness parameter R(h exp + ), is independent of the width of the velocity profile. The dependence noted by previous investigators was due to an assumption that the slope of the law of the wall for roughened surfaces is constant and equal to that for smooth surfaces. (ERA citation 04:046448)