【摘要】 采用一维和三维k-ε紊流数值模拟方法相结合,对宽深比达到500∶1的尾水渠水流流场进行了模拟。利用一维计算速度快的优点对30个尾水渠体型共60组工况进行了水面线计算,对壁面糙率进行了敏感性分析,提出了满足设计要求、工程量最省的体型。利用三维k-ε数值计算能得到详细流场的优点,分析了不同机组开启时尾水渠内流速分布和水面特性。研究结果表明:推荐方案在小流量时能满足尾水管出口的埋深,在大流量时保证设计有效发电水头且工程量最省。更多还原

【Abstract】 Both the one-dimensional and three-dimensional k-ε turbulent models are used in this paper to simulate the flow in the shallow tailrace with a ratio 500∶1 of width to depth.Water surface profiles of 30 kinds of configuration are computed by one-dimensional model and velocity fields by three-dimensional k-ε turbulence model.Sensitivity analysis on the effect of roughness of the bed is presented.Relying on above analysis,the shape of the tailwater channel is proposed,which is the most economical and can meet the design requirement.Furthermore,the three-dimensional k-ε model is used to obtain the detailed velocity fields of the turbulence flows.The flow fields in the tailrace are analyzed on the different conditions of generating units operation.The results show that the recommended program can meet the requirements of the enough submerged depth above the outlet of tail pipe with small discharge and the designed effective power head with large discharge.The recommended cunfiguration is also the most economical program.更多还原