Study On The Dynamic Impact Load Of The Bottom Plate Of The Water Cushion Pond Under Different Collision Angles Of The Self-entrained Falling Jet

The energy dissipation pattern of the dam body is commonly used in the high arch dam in the canyon area,and the practice shows that the flood discharge through the dam body is the most economical and effective type of the high arch dam in the canyon area.In the project of high arch dam,the water cushion pond is the main anti-erosion and energy dissipation building,its stability affects the overall safety of the hydraulic construction,and the main factor causing the serious scour and instability of the water cushion pond floor is the huge energy from the discharge.In the study on the water cushion pond floor load characteristics,although pick down stream water cushion pond of most of the energy is consumed by water cushion inside,but the water cushion pond of jet impact to the floor,its energy is bigger,still still high flow velocity,and the carrying part of kinetic energy in the impact zone into pressure energy,namely the impact on the water cushion pond floor load.In order to effectively realize the purpose of energy dissipation and flood prevention and ensure the safe operation of the dam,it is a long-term and important research subject to study and analyze the dynamic water load characteristics of the water cushion pond.By means of hydraulic model test and theoretical analysis,this paper analyzes the load characteristics of the floor of the sewer pond with different impact angles of the discharge water.The main research results are as follows:Based on the basic theory and research results of turbulent impingement jet,the characteristics of the flow pattern in the water cushion pond were analyzed,and the typical submerged impingement jet flow pattern was divided into three sections: longitudinal,transverse and horizontal.(2)Analysis of the distribution of aeration concentration and the mechanism of gas migration and diffusion;Analysis and cause of formation of average pressure distribution in floor measurement.(3)By means of mathematical statistics,the amplitude and frequency spectrum characteristics of pulsating pressures in different water flow structures are studied and analyzed.(4)The hydrodynamic parameters of air collision of discharge water are calculated and deduced.(5)The calculation formula of the average pressure at any point in the impact zone of the water cushion pool floor is derived.