m. sajjadi

One of the structures for regulating the water level in the irrigation and drainage ducts is the lopac gates, which are proposed as a structure for regulating and controlling the flow level. In this study, a new design of this type of structure has been proposed in which the gates are placed next to each other in pairs, and they are called multiple lopac gates. The objective of this research is to investigate the effective hydraulic parameters of the proposed structure and compare it in a case where a gate is used under the same conditions. All the simulations were modeled with 3 amounts of opening 30, 45, and 60 degrees and at 3 flow rates of 20, 40, and 60 liters per second and using Flow3d software, in these simulations, the number of mesh cells is 1000000 and RNG turbulence model is used.  The results showed that the maximum shear stress was reduced by an average of 38% compared to the single gate mode in most tests at different openings and flow rates using multiple lopac gates, and the largest amount of this reduction was related to the opening of 45 degrees, and the flow rate is 40 liters per second with a value of 76%. Also, the forces acting on the gate at different flow rates and openings will be reduced by 150% on average. In the qualitative investigation of flow vortices, the investigations also showed that vortex range, length, and strength are reduced compared to the single gate mode when two gates are used, and the number of vortices increases compared to when a single valve.