Numerical modeling of open channel flow with broad-crested weir

The velocity field of the flow over a broad crested weir is measured using a one-dimensional Laser Doppler Anemometry (LDA) for two different flow conditions. Using standard k- ? , RNG k- ? , Realizable k-?, SST, Modified k- ? and RSM turbulence closure models, the basic equations are solved by ANSYS-Fluent package program based on finite volume method for the same experimental conditions. The volume of fluid (VOF) method is used to compute the free surface of the flow. GCI (Grid Convergence Index) is performed to examine the effect of the selected grid structure on the numerical results. The numerical results for the velocity field and flow profiles are compared with the experimental results for validation purposes. The comparisons of the numerical and experimental results show that the numerical simulation using the RNG k?? turbulence closure model predicts the velocity field and free surface profile more accurately compared to those of the other turbulence models used in the present study.