Investigation of Stress Tensor Anisotropy in Two- and Three-Dimensional Dunes

Investigating the creation of bed forms due to sediment transport and flow structure in the presence of bed forms in alluvial channels is a constant challenge for engineers and researchers, because of its complex nature. In this research, turbulent flow structure and turbulence anisotropy in the presence of two- and three-dimensional laboratory dunes were investigated. The results showed that, at the reattachment point, the turbulence anisotropy at the centerline of a three-dimensional dune was the largest. On the stoss slope, the turbulence anisotropy for two-dimensional dunes was at its highest at the bed form’s trough and below the crest. The results also demonstrated a tendency at the crest line toward the plane–strain limit for two-dimensional dunes and the centerline of three-dimensional dunes. However, at a 20 cm distance, turbulence anisotropy at the crest line tended toward asymmetric contraction to an oblate spheroid.