Ali Akbar Akhtari

A b s t r a c t There is a lack of insight in the application and comparison of CFD models on numerical simulation of water flow in sharp open channel bends. In this paper, we report on successful numerical experiments in curved bends, which are conducted using two commercial finite-volume and finite-difference models (FLUENT and FLOW3D). A comparison of numerical results was carried out based on a collation with experimental data. The models are validated against experimental results. All salient features of the water flow which can be found in the experimental measurements can be identified in the numerical results of both CFD packages. Consequently, FLUENT has the advantage of employing irregular meshing forms, thus being less CPU-intensive than FLOW3D. However, FLOW3D benefits user-friendly pre-processing tools. According to the results, it is evident that FLOW3D shows better performance over FLUENT. Slight discrepancies were noted, which can be credited to the different numerical techniques used to conduct the simulations. The calculated RMSEs for FLUENT and FLOW3D are 7.9 and 4.5 for the velocity results, and 0.9 and 0.29 for the water level results, respectively. Since, it is evident that the accuracy of the obtained results significantly depends on the grid form; more precise numerical results can be obtained by conducting a mesh analysis study.