Measurements of Bed Load in Oscillatory Flow

Measurements have been made of the quantities of sediment moving as bed load in oscillatory flow over a flat bed. Most of the measurements were made with an oscillating tray in still water but some were carried out in a wave flume. There is good agreement between the two sets of results. For sand and gravel the mean sediment transport rate is observed to vary during the course of the cycle like the fourth power of the velocity of oscillation but with a slight phase lead. For nylon pellets, however, the transport curve is not quite symmetrical about its maximum. Measurements were also made of the random fluctuations in transport rate and these are compared with Abou-Seida's theoretical model. An empirical relationship is derived for the sediment transport rate.