宽尾墩体型对宽尾墩+阶梯溢流坝+消力池消能方式中阶梯掺气空腔长度及负压影响研究  

Study of impacts on aerated cavity length and negative pressure by Y-shape flaring gate pier combined with stepped spillway in energy dissipator

作　　者：后小霞 杨具瑞[1] 甄建树 

机构地区：[1]昆明理工大学现代农业工程学院,昆明650500 [2]中建一局集团第二建筑有限公司,北京100068

出　　处：《水力发电学报》2014年第3期203-209,215,共8页Journal of Hydroelectric Engineering

基　　金：水利部公益项目(20110025)

摘　　要：宽尾墩+阶梯溢流坝+消力池消能方式在我国得到了广泛的应用,其中宽尾墩体型参数主要是收缩比。本文采用水气两相流VOF方法的三维RNG k-?紊流模型,利用几何重建格式进行水气面附近的插值,速度与压力的耦合方式采用PISO算法,用非定常流算法逼近定常流的稳定解,对宽尾墩收缩比?分别为0.7、0.445和0.4的Y型宽尾墩+阶梯溢流坝+消力池的阶梯掺气空腔长度和负压进行了数值模拟,模拟范围从上游库区至下游消力池尾坎。并对阶梯掺气空腔长度进行实验,通过实验和模拟结果的对比分析,阶梯掺气空腔长度与实测空腔长度基本吻合,最大误差为10.0%。因此该数值模拟具有一定的合理性和可靠性。模拟结果显示,掺气空腔长度随收缩比?减小而增大,阶梯最大负压随宽尾墩收缩比?的减小而减少,但阶梯负压分布范围逐渐扩大。The energy dissipater of flaring gate pier combined with stepped spillway is widely used in China. This paper presents a numerical simulation study of aerated cavity length and negative pressure that vary with the contraction ratio of symmetrical flaring gate pier. A RNG k - e turbulence model and a water vapor two-phase VOF model were applied to the simulation, with a geometry reconstruction scheme for free surface generation by iterative solution, a velocity-pressure coupling method using PISO algorithm, and an unsteady flow approach for steady flow iteration. Three contraction ratios of 0.4, 0.7 and 0.445 were simulated and the computational domain covered the section from the upstream reservoir to the downstream stilling basin. The calculated cavity length has been verified by comparison with experimental measurements and its relative errors are below 10%, showing good reliability of the simulation. Results also show that as the contraction ratio decreases, the cavity length is increased and the lowest negative pressure become higher, but the extent of negative pressure expands on the steps.

关 键 词：工程水力学 三维数值模拟 RNG K-Ε紊流模型 掺气空腔 

分 类 号：TV135[水利工程—水力学及河流动力学]