东庄水利枢纽表孔宽尾墩水力特性研究

Study on hydraulic characteristics of broad tail pier of surface spillway in Dongzhuang project

为了验证东庄水利枢纽表孔宽尾墩初设方案的泄洪消能特性,在水工模型试验的基础上,采用三维水流的RNG k-ε紊流双方程数值模型、自由面的VOF处理法来模拟表孔宽尾墩水流特性。根据东庄水利枢纽的初设方案,计算了宽尾墩的泄流能力、流道内的水面线以及水舌的纵向扩散长度和水垫塘的时均冲击压力,并将相应的试验值与计算值相结合进行了对比分析,发现两者吻合度较高。对比结果表明:2#表孔出口俯角偏小,在高水位时泄流能力受到宽尾墩的影响低于设计值,各工况下ΔPmax均小于15×9.81 k Pa的防护标准,初设方案收缩比偏大、墩尾折角偏小,水舌纵向扩散效果不明显,无法实现表深孔无碰撞消能的效果。

In order to evaluate the feature of flood discharge and energy dissipation of broad tail pier of surface spillway in the primary scheme of Dongzhuang project , the paper used RNG k-εtwo-equation-al model for 3 D turbulent flow and the VOF method to numerically simulate the feature of water flow of broad tail pier based on hydraulic model test .According to the primary scheme , the paper calculated dis-charge capacity , water surface curve , velocity, longitudinal length of water and impact pressure in the plunging pool , and compared the results of calculation and test ,and found both the result are in good a-greement .After the comparison of those values of model test and calculation ,it shows the broad tail pier have affected the discharge of surface spillway No .2 under high water level;ΔP max is under the protection standards of 15 ×9.81kPa.The contraction ratio of preliminary design scheme is too large and , piers an-gle is small, the effect of longitudinal diffusion of water tongue is not obvious and is unable to realize the effect of no collision free energy dissipation in surface deep hole .