Author(s): Cristopher Gamboa Monge; Ana Maria Ferreira Da Silva
Linked Author(s): Ana Maria Ferreira da Silva
Keywords: No Keywords
Abstract: Large-scale coherent turbulence structures encompass the largest conglomerations of eddies rotating vertically (around horizontal axes) or horizontally (around vertical axes). This study centers on large-scale horizontal coherent structures (LSHCSs). Despite their relevance in sediment transport, pollutant dispersion, and fluvial configurations, LSHCSs remain unexplored within ice-covered scenarios. This work aims to address this gap by investigating LSHCSs' scales and life-cycle under such conditions. The approach involves instantaneous flow velocity measurements in a flume using a 2D Micro Acoustic Doppler Velocity (ADV) meter. The simulated ice-cover consisted of extruded polystyrene with mesh; smooth concrete served as streambed. Lowpass filters and Continuous Wavelet Transform (CWT) were used to estimate the characteristic scales of LSHCSs. This study highlights the significant effect of ice-covers on the characteristic scales of LSHCSs, resulting in a reduction of approximately 14% compared to its equivalent open-channel condition. This finding is relevant as it suggests that in scenarios with a movable bed, the length scale of the related bed and plan forms is likely to also be impacted.
Year: 2024