Experimental Investigation of the Effect of Froude Number on the Vertical Distribution of Suspended Sediment Concentration in a Laboratory Flume

Surface water basins play a crucial role in managing urban runoff and mitigating its hydrological and pollution impacts on downstream waters. Suspended sediment concentration (SSC) is vital for understanding river dynamics and environmental hydraulic management; however, accurately estimating it is challenging due to complex hydraulic, hydrologic, and sediment interactions. This study investigates the effect of the Froude number on the vertical distribution of SSC in a ۶-meter laboratory flume using silica particles (۰.۰۷۵ to ۰.۱۵ mm). Flow velocity was measured using an Acoustic Doppler Velocimeter (ADV), and sediment samples were collected at different depths using a siphon sampler. Dimensionless parameters (C/Co and z/h) were employed to analyze concentration profiles under different Froude numbers (۰.۲۰, ۰.۲۷, and ۰.۳۰). The results revealed distinct SSC patterns: at Froude numbers of ۰.۲۰ and ۰.۲۷, upstream profiles resembled Rouse distributions with high concentrations near the bed. At a Froude number of ۰.۳۰, increased turbulence led to the upward transport of coarser particles. These findings highlight the critical role of the Froude number in shaping SSC profiles and underscore the need for improved models to predict sediment transport more accurately.

کلیدواژه ها:

Froude Number ، Suspended Sediment Concentration ، Vertical Concentration Profile