Investigation of Optimal Hydraulic Cross Section in Two-Section Parabolic Channels

Among all of the sections that can transport a discharge, the best hydraulic section is to provide the least wetted perimeter. In this study, attempted to find the optimal hydraulic cross section of two stage channel with parabolic cross section and flat width parabolic. Therefore, by constant considering the amount of area and wetted perimeter as the objective function, optimal hydraulic geometrical parameters for two types of channel were obtained and the equations of best hydraulic cross section of each type were extracted. The results show that: Optimal Type 1 model, for the certain discharge, roughness coefficient and bed slope, the least wetted perimeter and as a result, it creates the lowest cost among other sections such as regular hexagonal half, and other types also it's much closer to the wetted perimeter of the semicircular section. Both types of proposed cross-sections also cost much less than optimal cross-sections of previous researches