Study On Fluid - Structure Coupling Vibration Of Plane - Standing Gate Under Submerged Condition

The gate is an important part of hydraulic structures and is used to control the flow by shutting and opening. The movement of water apply hydrodynamic forces to the gate surface and cause the gate vibration and deformation by changing force boundaries of the gate when the gate directly contact with the water. Therefore, it is significant to study the influences between gate vibration and unsteady flow field by the modern numerical simulation methods and the synchronous fluid-structure interaction test.In this paper, the hydraulic test model and numerical simulation method are used to investigate the fluid-induced vibration of plane gate. The main contents and results are as follows:(1) A full flow path three-dimensional model including plane gate was established by modeling software GAMBIT and through Boolean operations to separate plane gate from fluid domain. Combining with the characteristics of flow, the flow field is meshed into several parts so that it can be harmonization of computational accuracy and efficiency.(2) Based on ANSYS-Workbench platform, the numerical simulation of flow field is carried out in Fluent software. The method of VOF is used to track complex free surface after the gate. Large eddy simulation (LES) and PISO algorithm were chosen to calculate unsteady flow field to analysis the flow characteristics in the small opening condition and achieve the instantaneous velocity, dynamic pressure, vortex and other parameters of the flow field.(3) The weak coupling method is used to calculate gate coupling in this paper. After the fluid-structure coupling effect of the plane gate, the change of displacements, stress were obtained. It reveals the main characteristics of gate vibration.(4) We have performed an experiment on the flow-induced vibration characteristics of hydraulic plane gate. The experimental model system made of PMMA materials and two accelerometers were arranged at the middle gate. Two independent measuring systems are used by changing the gate opening and flow in experiment. One is 8 channels high speed vibration acquisition system which measures velocity, acceleration and displacement of plane gate and the other is a 3D velocimetry PIV to measure the flow field velocity for simultaneous testing in time. The measurements obtain dynamic distribution characteristics of the flow field and vortex structure evolution process around the gate. The results can provide a hydrodynamic basis for hydraulic gate vibration problems.