Numerical Simulation of Turbulent Flow and Local Scouring Around of Spur Dike Straight and Angles by FLOW-3D

Examining the properties and behavior of the flow in the rivers and its associated structures is one of complex phenomena that make the use of software inevitable. First, the results of laboratory test carried out by Duan et al. (2009) in Minnesota university, are used verification and comparison of numerical simulations of FLOW-3D(version 9.3). The vertical spur dike was first simulated to verify the model results and the inclined spur dike with 60° and 30° to the flow direction was then considered. The simulation performed with FLOW-3D, for 650 seconds using turbulence models (k-ɛ, RNG, LES). By comparing different turbulence models with experimental results, the maximum scour depth at the tip of the spur dike was 8.82 cm. Then the maximum scour depth calculated by FLOW-3D in the turbulence models of (k-ɛ, RNG, LES) was 9.1, 8.9, 9.1 cm. So the error in RNG turbulence model is about 9 %, compare to the turbulence model k-ɛ, and of LES shows more agreement. In the simulation, the maximum scour depth at the tip of the spur dike 60° and 30° was 8.75 and 6.5 cm respectively.