Turbulent flow over three-dimensional dunes: 2. Fluid and bed stresses

摘要: [1] Dunes formed in response to fluid flow exert a total boundary stress on the that is made up of form drag and skin friction, latter which generally considered important for predicting sediment transport dune evolution. Previous research has used various methods estimate its subcomponents, with recent work suggesting application spatial average equations motion. A complete, three-dimensional (3-D) this analysis derived applied measurements turbulent open-channel over 3-D dunes. Spatial averages Reynolds shear stresses dunes cannot be predict stress. However, estimations from spatially averaged motion agree not only sum friction but also direct free surface slope. Form-induced secondary circulations augment relatively low These turbulence levels have ramifications predictions, use prediction must account these so as overpredict rates.