连续弯道中簇状刚性植被对水流湍流特性影响的试验研究OA

The turbulence characteristics of continuously curved water flows are significantly influenced not only by the channel shape but also by the widely distributed clustered vegetation within the channel.This vegetation alters the hydraulic properties of the flow,thereby affecting sediment transport and riverbed evolution.To investigate this phenomenon in depth,this study systematically measured the three-dimensional velocity field in a controlled flume experiment,focusing on the distribution patterns of time-averaged flow velocity,Reynolds stress,quadrant analysis,turbulent kinetic energy,and turbulent power spectral density before and after the presence of tufted vegetation.The results reveal that clustered vegetation significantly expands the high flow velocity regions while reducing the low flow velocity areas,leading to increased inhomogeneity in the flow velocity distribution and disrupting the vertical profile of the longitudinal flow velocity,causing it to deviate from the logarithmic distribution.Additionally,vegetation enhances the overall turbulent kinetic energy,particularly at the bend apex and downstream section,where high-energy vortex clusters form.Changes in flume curvature dominates the dominant quadrant flow regime,with vegetation exacerbating these changes to a limited extent.The turbulent power spectral density remains invariant in the absence of vegetation but varies with water depth when vegetation is present,with overall levels significantly lower than those without vegetation.These findings underscore the important role of clustered vegetation in river dynamics,suggesting that optimized vegetation configurations can regulate flow regimes,protect riverbeds,enhance ecological functions,and support sustainable river ecosystem health.