Study On FLUENT Numerical Simulation Of Anti - Arc Falling Bottom Flow Energy Dissipater

The energy dissipater with step-down floor is a new type of the conventional energy dissipater developed on the basis of the conventional energy dissipaters of hydraulic jump,the hydraulic index in the stilling basin of can be reduced effectively. The energy dissipater with step-down floor with the sill depth increases, stilling the largest temporary bottom velocity decreases, when the floor of both the hydrodynamic pressure decreases. When high head, chute angle steeper, lip bottom energy dissipator its larger impact load flow, flow attenuation is small, often requires deep down floor, increasing construction costs. But in the downstream water level is higher and the topography and geology conditions allow, through the segment will increase the flow point of view, to avoid a direct impact on the bottom of the stilling basin, it can effectively reduce the stilling basin drop in the biggest bottom velocity and average dynamic water pressure without any increase in deep case.Firstly, three-dimensional numerical simulation of the energy dissipater with step-down floor, and then were analyzed by simulation and experimental results, to verify the feas bility of the energy dissipater with step-down floor dimensional numerical simulation. Then we use numerical simulation method for hydraulic characteristics of indicators ogee type lip bottom - flow dissipation calculated.And the use of hydraulic model test method to verify the results of the numerical simulation. Finally, the use of numerical simulation alone change ogee type lip bottom energy dissipator ogee elevation angle calculated the impact of different ogee lip bottom elevation of energy dissipator stilling pool hydraulic characteristics to guide future corresponding model test. This paper can follow conclusions:(1)By the three-dimensional numerical simulation of the energy dissipater with step-down floor, it is concluded that the three-dimensional numerical simulation method is applied to drop type underflow energy dissipation is feasible.(2)By numerical simulation method lip bottom energy dissipator stilling basin flow field simulation, obtained lip bottom - flow dissipation in additional anti-arcs can improve lip stilling pool flow pattern and energy dissipation rate. At the same time when you can increase the height of the tail ridge way to optimize the water flow is large mechanical index.(3)By hydraulic model test method, the ogee type lip bottom - flow dissipation measurements, the same conclusions and results of numerical simulation methods, while the measurement results of the model tests and simulation results were compared to further explain research on anti-arc lip underflow work is feasible using numerical simulation.(4) By numerical simulation method, in the case of larger flow into the pool, separate changing incident ogee type lip underflow energy dissipater ogee elevation and angle of incidence are simulated, through the analysis of the calculation results, obtained an appropriate increase in anti-arc bottom lip energy dissipator of ogee elevation to avoid major direct impact Stilling, making lip stilling pool flow pattern better energy dissipation, and the ability to shift position after the point of impact, and the floor at the point of maximum impact bottom pressure decreases, temporary bottom velocity decreases. With the increase of incident angle, lip stilling pool water line height is reduced, the impact zone plate pressure increases, the bottom velocity increases.