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多股跌扩型底流消能是一种新型消能方式,消力池内紊流特性复杂。本文对多股跌扩型底流消能工建立了三维紊流数学模型,采用非均匀结构网格技术对模型进行网格划分,利用RNGk-ε紊流模型和VOF自由表面追踪法对其进行高精度数值计算,得到了消力池内水流的水力特性:当表孔和中孔联合泄流时,消力池后段的临底流速较低,流速梯度改变较大,消力池底板及跌坎附近形成了强度和尺度各异的游离性和间歇性漩涡,紊动能消逝迅速。由此可见,此种消能工的消能效果显著,能有效解决高水头、大单宽流量消力池水力学指标过高的水力问题。
Multi-unit drop expansion type underflow energy dissipation is a new type of energy dissipation, turbulent flow pool complex characteristics. In this paper, a mathematical model of three-dimensional turbulence is established for multi-unit drop-expanding underflow dissipater. The model is meshed using non-uniform structure grid technique. The model is developed using RNGk-ε turbulence model and VOF free surface tracking method The accuracy of the numerical calculation, the hydrodynamic characteristics of the flow in the stilling pool are obtained. When the discharge of the surface hole and the middle hole is combined, the flow velocity at the rear of the stilling pool is lower and the gradient of the flow velocity changes greatly. Near the formation of the strength and scale of different free and intermittent vortex, turbulence can disappear rapidly. It can be seen that this type of energy dissipater has significant energy dissipation effect and can effectively solve the hydraulic problem of excessively high hydraulics index for high head and large single wide flow slug cells.