Experimental Study On Aerated Concentration And Fluctuating Pressure Of Multiple Aerated Water Streams In A Plunge Pool

China's water conservancy construction has achieved rapid development.A large number of high dams have been built.Many of the dams built are above 70 m.These dams generally have the characteristics of high water head,large flow,and narrow river valleys.Become a key point in the construction project.For high arch dams,most of the current projects use plunge pools as a form of downstream energy dissipation.For the study of the water dissipation and energy dissipation of the high arch dam,the experience and theory are combined.Many scholars at home and abroad have done a lot of research on the hydrodynamic load in the plunge pool,and have also obtained relatively mature results,while the aerated water flow on the water cushion There are few studies on the effects of hydrodynamic loads in ponds,especially the multi-strand aerated jets have less research on the hydrodynamic loading of the plunge pool floor.Water aeration can effectively reduce or avoid cavitation damage,which is an effective method.As the water flow aeration will cause the water depth in the water cushion pond to increase,the water body flow velocity changes,the time-averaged water pressure and the pulsating pressure change,and the water flow pulsation is the main cause of the damage of the water cushion pond floor.In this paper,the effects of multiple aerated water flows on the floor load of the plunge pool are analyzed by the combination of physical model test and theory.The main research results are as follows:(1)The flow pattern of the water body in the plunge pool is analyzed,and the water flow structure of the submerged impinging jet is divided.(2)The bottom hole,the middle hole and the surface hole were respectively drained,and the aeration concentration,the time-averaged hydrodynamic pressure,and the distribution of the pulsating pressure in the plunge pool were changed.(3)Study the bottom hole + mesopores combined drainage,bottom hole + surface hole combined drainage,mesopores + surface hole combined drainage,change the aeration concentration,time-average hydrodynamic pressure,and pulsating pressure when entering the pond flow The distribution within the plunge pool.(4)Analyze the effect of aeration concentration on time-averaged hydrodynamic pressure and pulsating pressure.