Wake simulations in shallow flows

Abstract

Paper presented at the 9th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Malta, 16-18 July, 2012.

Three-dimensional numerical modeling using Detached Eddy Simulation (DES) has been carried out to study the characteristics of shallow wake flow. The features of shallow wake flows are highly dependent on the bed characteristics, the free surface and the non-uniform approaching flow velocity profile. An approaching flow with fully developed boundary layer was employed to model the effect of the shallow flow. The shallow wake is generated by introducing a disturbance in the form of a bluff body placed in an open channel. A sharp- edged bluff body is used to reduce the flow sensitivity to Reynolds number and maintain a constant position for boundary layer separation. The flow field structure in the wake i.e., the mean and turbulence characteristics, are examined and compared at different downstream locations to evaluate the effect of vertical variability from the bed. Available experimental data have been used to validate the computational results.