VARIATION OF SEDIMENT SUSPENSION IN OSCILLATORY FLOW

Abstract

Different syphon type suspended load probes were used together with a newly developed 'carousel' sampler for measurements of the instantaneous sediment concentration in turbulent oscillatory flow over a sand bed. Shields parameters were well above the rippled/flat bed transition region, resulting in intense sediment transport over a flat bed. The measurements were performed at different levels in a large oscillating water tunnel. They showed some characteristic features of the temporal concentration variation and of the variation with height of the mean concentration. Also a pronounced effect of the orientation of the suction tube relative to the flow was observed.