不同坡降影响下弯道式引水渠首水流三维数值模拟研究

3-D Numerical Simulation for Water Flow in Bend-type Intake Headworks under Different Slope

采用基于VOF法的RNGkε-紊流模型,对不同横向坡降下的弯道式引水渠首水流进行三维数值模拟,分析了弯道段渠底坡降对水流速度场的影响。计算结果表明:存在一定横向坡降的弯道较平坡相比,在凹岸处增加了一个与主环流同向的小环流,且其纵向主流速最大值向凹岸偏移程度大于平坡。由此得出,存在一定横向坡降时的弯道式引水渠首的水流流速结构更有利于引水渠首引水排沙的需求,能更好的满足实际工程需要。

The RNG k-ε turbulence model based on VOF method is employed to numerically simulate the 3-D flow field of bend-type intake headworks under different lateral slope,and analyze the gradient effect on the flow velocity field in the bottom of the channel.The results show that compared with the bend with relatively flat slope,a little contrast with the mainstream velocity circulation is added in the concave bank of the bend with a certain horizontal gradient,and its maximum vertical speed of the mainstream would shift to a greater extent than flat concave slope.Thereby,it is obtained that the flow velocity struture of the bend-type intake headworks with a certain horizontal gradient would be more conducive to the needs for water diversion and sediment flushing,and could meet the needs of practical engineering.