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Experimental results on sand transport under waves in large-scale wave flume

The paper presents some results of a study based on the experiment carried out in Delta Flume of Delft Hydraulics. The analysis of time-series of sand concentration and velocity are implemented for regular and irregular waves with different conditions on wave and grain size. | Vietnam Journal of Mechanics, NCS'.f of Vietnam Vol. 22, 2000, No 3 (149 - 166) EXPERIMENTAL RESULTS ON SAND TRANSPORT UNDER WAVES IN LARGE-SCALE WAVE FLUME Huu CHUNG Institute of Mechanics, NCST of Vietnam DANG ABSTRACT . The paper presents some results of a study based on the experiment carried · out in Delta Flume of Delft Hydraulics. The analysis of time-series of sand concentration and velocity are implemented for regular and irregular waves with different conditions on wave and grain size. From measured·concentrations and velocities the suspended transport components are calculated and some interesting information is obtained. At the same time some formulae for calculations of suspended sediment transport have been proposed and verified. A general evaluation on the total sediment transport rate over the water depth has been given on the basis of incorporating measurement, extrapolation and bedload prediction. 1. Introduction Sediment transport is a very complicated natural process and so far it is not fully understood yet. Therefore every different attempt to achieve knowledge on this phenomenon in some measure is always encouraged. The current-related transport component involves th~ convective sand transport carried by the mean currents such as tide, wind and wave-driven currents in the presence of short (high-frequency) surface waves acting as stirring agents. The wave-related sand transport is herein defined as the transport of sand particles by the oscillating fluid motion due to the high-frequency waves. The current-related transport over rippled beds has been studied in considerable detail (Van Rijn et al., 1993; Van Rijn and Havinga, 1995), but the wave-related transport is less well known. The wave-related transport over a flat bed has been studied in more detail based on numerous experiments in wave tunnels (see for· overview: Ribberink, 1998). Within this purpose the paper presents some results on the analysis of time series of concentration and