Author(s): Il Won Seo; In Hwan Park; Sung Won Park; Jae Hyun Shin
Linked Author(s): Il Won Seo
Keywords: Heterogeneous mixing; Meandering channel; Dispersion tensor; Primary flow; Secondary current; 2-D water quality modeling
Abstract: A two-dimensional advection-dispersion model was applied to investigate the effect of heterogeneous dispersion tensor on the tracer mixing in meandering channels. Two different dispersion tensors were incorporated into the numerical model. First type was calculated by integrating the vertical deviations of stream-wise and span-wise velocities, while the second type was just based on the depth-averaged velocities. Measured dispersion tensor from experimental data showed that the first-type dispersion tensor varies in both longitudinal and transverse directions in laboratory meandering channel whereas the second type varies mainly in the longitudinal direction. Furthermore, simulation results by 2D model revealed that concentration contours computed with first type dispersion tensor show span-wise tracer mixing more specifically than second type dispersion tensor. This means that first-type dispersion tensor adequately represents the effect of secondary currents developing alternatively in meandering channels.
Year: 2011