Study On Hydrodynamic Characteristics Of Flaring Gate Peers-Stilling Basin

In energy dissipator design, the principle of Joint application of flaring gate peers and bottom flow is as follows: most of water flow energy is dissipated through that the adjacent water interface in Ogee Section attenuating from both sides and colliding and mixing in water cushion pool, which thus can form spatial 3D hydraulic jump inside the plunge pool, and strengthen the effect of flow turbulent shear for dissipation, except that the confluence and aeration of impinging jet on the weir crest can dissipate a small part of water flow energy. Because of the lack of full understanding on turbulent flow internal mechanism, the study on flow fluctuating pressure only in theory is very difficult. So, at present, we study the correlative problems needed to be solved urgently in engineering mostly based on hydraulic model test.A hydroelastic model of Guandi hydropower station in Sichuan with the energy dissipation scheme of"Flaring gate piers on overflow surface bay+Continuous drops+Bottom flow stilling basin+Deflecting flow by medium outlets"is established. The flow characteristics of ogee section and the force on stilling poor is studied in this paper, relied on the model test and based on the study results of predecessors .The main work of this paper can be concluded as follows:1. Water flow regime in the ogee section of overflow dam and stilling poor has been observed in the different working conditions of Y flaring gate piers. The time averaged pressure, fluctuating pressure on the up-down surface of the floor and uplift on the floor is analyzed in time domain, frequency domain and amplitude domain. The correlation of those forces is also analyzed.2. The time averaged pressure, fluctuating pressure and uplift on floors on the ogee section of overflow dam and the stilling basin on the condition of different shape flaring gate piers (X type and Y type) is analyzed comparatively. Then the influence of flaring gate piers with different shapes on the flow parameters of the ogee section of overflow dam and the stilling basin and also on the uplift on floors is gained.3. The height of X-flaring gate piers down edge is changed to research its impact on the experiment result.4. Considering that the floor plate of plunge pool has larger thickness, whose safety coefficient thus is higher, the paper studied the changes of uplift on floors of plunge pool by decreasing its thickness. 5. The correlative information of complex flow field is limited as a result of inherent limitation of model experiments and testing device. So, this paper simulated the flow field of ogee section of spillway dam and stilling basin through numerical simulation besides model experiment, to remedy defects of it.