عنوان مقاله [English]
In this paper, Flow3D software was used to simulate the hydraulic flow in the relaxation pond. In addition to evaluating the accuracy of the model in simulating the flow pattern in the relaxation ponds, the numerical study of the effect of the shape and dimensions of the threshold blocks on the energy dissipation rate And the hydraulic jump of the pond was relaxed. First, using the laboratory data of Petra (1958), the mathematical model (Flow3D) was implemented and calibrated for the relaxation basin. Then the software was evaluated and tested for different geometric and hydraulic conditions. In order to select the best turbulence model as software calibration, we compared the results of the initial depth of the hydraulic jump and the secondary hydraulic jump depth from three different models of turbulence. Also, for calibration of the software, the boundary conditions of the channel were investigated and it was concluded that by selecting the input boundary boundary condition, the results of numerical calculations of the primary and secondary depth of the hydraulic jump in the relaxation basin are closer to the related laboratory data. In the following, for numerical analysis, the effect of block shapes on the amount of energy depletion of the current, the dimensions and block distance were changed with coefficient 2, and the modeling was done and it was concluded that in general, the increase and decrease of the height of the threshold blocks, as well as the change in The distance between the threshold blocks on the characteristics of the flow and the depths of the primary and secondary hydraulic jumps as well as the amount of energy losses have different effects and in some cases, it increases the amount of energy depletion and, in some cases, decreases it. And since increasing the amount of energy depreciation is desirable, so, in different situations, the reduction of the distance between the threshold blocks, both in the place of the threshold blocks and in the location of the block, the location of the hydraulic jump, will increase the energy depreciation. For us, as The most optimal mode was chosen.