泄洪洞中闸室出口侧墙掺气体型研究

为消除中闸室出口侧墙上的掺气盲区并且改善水流流态,该文提出了突扩-渐扩侧掺气体型。采用RNG k-ε紊流模型对此掺气体型进行数值模拟,获得了侧墙上水流流态、压力分布以及水翅强度等水力特性。利用物理模型试验对计算结果进行验证,计算结果具有可靠性。结果表明:出闸水流弗劳德数一定时,侧墙突扩宽度和渐扩长度是影响水翅强度的主要因素,突扩宽度越大或渐扩长度越短,水翅强度越大;侧墙压力中心主要是由出闸水流冲击泄洪洞底板造成的;此掺气体型能形成稳定侧空腔并且侧墙上无负压产生,能够有效避免空化空蚀。

Study on the sidewall aerator shapes at middle gate chamber in spillway tunnel

The sidewall aerator with sudden enlargement and gradual expansion can eliminate the unaerated area at the sidewall of middle gate chamber and improve the flow regime.RNG k-ε turbulence model is employed to simulate the hydraulic characteristics including flow pattern,pressure distribution and the intensity of water wing,and the computational results are validated by the physical model test data.Results show that the geometries of sidewall aerator are the main factors influencing the intensity of water wing when the Froude number is certain.The greater width of the sudden enlargemen or the shorter length of gradual expansion,the intensity of water wing will be greater.Sidewall pressure center is mainly caused by flood impacting the tunnel bottom,and there is a stable cavity and no negative pressure at the sidewall.This aerator can avoid cavitation and erosion effectively.