ANALYSIS OF MULTIPHASE FLOW UNDER PARTIALLY OPEN FLOODGATES IN A SITUATION OF MAXIMUM FLOOD USING A NUMERICAL MODEL

Abstract

Hydraulic gates are structures widely used to control discharge and runoff depth in irrigation channels, sewage treatment stations, dams, in the São Francisco River transposition system, among other hydraulic structures. Flaws in the mechanisms for opening the gates are recurrent in these structures. These failures in the operation of the gates combined with a critical event of maximum flood can lead to the collapse of the system. In this work, a study was carried out of a flow under a partially open hydraulic gate in a channel with the maximum amount level, using a CFD program, Ansys CFX. This software uses the Finite Volume Method for domain discretization. In order to generate the model, a mesh convergence test was carried out, the residues of the simulations in the permanent and transient states of the flow were also compared. The study identified a region of flow separation near the gate. Another point studied was the hydraulic pressure generated by the flood in the structure, with the finding of a region of elevation of the values of the stresses that coincides with the zone of separation of the flowe.