Dam Analysis with Gabions Geometry Through CFD (Computational Fluid Dynamics)

The Gabions was used in the first time as an engineering solution in 1893, in the Reno River bank protection, at Bologna city, Italy. Over the years that solution has been applicated in other functions like, channeling, retaining wall, and dam. The last one has awakened the engineers interest because the simplicity, flexibility, low environmental impact, and low cost. In 2004 the FCTH (Foundation Hydraulic Technology Center), of USP (University of the São Paulo state) developed a physical modeling about gabion dam, and studied some parameters as stilling basin length, height of the end sill, dissipation capacity and other values. In 2018 it was developed a computational modeling using the software OpenFoam (open code), with the intention of validating that tool for the application in the dam gabion. The gabions geometry used in that study followed the same dimensions of the physical model, the scale used was 1:6. The calibration was done comparing some values of the physical modeling, as discharge, water level, velocities, and structure geometry. As the model has two-dimensional, it was necessary to include an air entrance near of the dam crest, and for that point it was necessary to calibrate the air discharge too. For the computational model it was applied a rectangular mesh, with almost 200.000 cells, and for the turbulence was used the k-e model. After the calibration step, the study entered in the validation phase, where the computational results were compared with the physical results. In validation step it could be noted that the results found with the software OpenFoam represented the same phenomenon that was studied in the physical modelling, but to achieve that results, it was necessary to calibrate all the parameters used in the physical model.