The Influence of Suspended Sediment on the Surface Reaeration of Uniform Streams.

摘要

The surface reaeration of uniform streams,with and without sediments in suspension,has been studied. Based on the premise that the reaeration rate is controlled by an effective vertical diffusivity at the free surface and by turbulent mixing beneath it,an equation was developed to predict the reaeration rate of uniform clearwater flows. The laboratory data gave support to the developed equation. This equation was then modified in order to account for the effect of suspended sediments on the surface reaeration of uniform sediment-laden streams. The new equation was substantiated by the experimental results,which indicate that the reaeration rate decreases as the average sediment concentration increases. The decrease was attributed to the dynamic influence of the suspended particles on the turbulent flow field. (Author)