高海拔因素对大型泄洪洞水力特性及通风补气影响数值模拟研究  

Numerical Simulation of the Influence of High Altitude on Hydraulic Characteristics and Ventilation of Large Spillway Tunnel

作　　者：苗宝广 周琦 王立杰 许传勇 MIAO Baoguang;ZHOU Qi;WANG Lijie;XU Chuanyong(PowerChina Zhongnan Engineering Corporation Limited,Changsha 410014,Hunan,China)

机构地区：[1]中国电建集团中南勘测设计研究院有限公司,湖南长沙410014

出　　处：《水力发电》2023年第6期46-56,共11页Water Power

摘　　要：为了保证泄洪安全,大型泄洪洞通常设置掺气减蚀设施和通风补气系统。随着海拔高度增加,大气压、大气密度将会显著降低,这些变化可能会对泄洪洞水流流态和通风补气造成不利影响。在考虑高海拔因素的前提下,采用RNG k-ε紊流模型和Mixture多相流模型对某大型泄洪洞的水气两相流场进行了数值模拟。研究发现:随着海拔高度增加,泄洪洞内的水流运动特性不受影响,但水流空化数显著减小,增加了空化空蚀风险;通风补气系统内的气流体积流量基本维持恒定,但质量流量会因为大气密度的减小而减小。在高海拔地区建设大型泄洪洞,建议按水流空化数设计掺气设施,并适当放大补气通道的尺寸以控制风速,以免产生有害噪声。In order to ensure the safety of flood discharge,large spillway tunnels are usually equipped with aeration and corrosion reduction facilities and ventilation and air replenishment system.With the increase of altitude,the atmospheric pressure and atmospheric density will decrease significantly.These changes may have an adverse impact on the flow pattern and ventilation of spillway tunnel.In this paper,the RNG k-εTurbulence model and Mixture multiphase flow model are used to simulate the water-gas two-phase flow of a large spillway tunnel.It is found that,with the increase of altitude,the flow movement characteristics in the flood discharge tunnel are not affected,but the number of flow cavitation decreases significantly,which increases the risk of cavitation erosion;the air volume flow in the ventilation and air replenishment system is basically constant,but the mass flow will decrease due to the reduction of atmospheric density.For the construction of large spillway tunnels in high altitude areas,it is recommended to design aeration facilities according to the number of flow cavitation,and appropriately enlarge the size of air supply channel to control wind speed and avoid harmful noise.

关 键 词：高海拔 泄洪洞 水力特性 掺气减蚀 通风补气 空化数 数值模拟 

分 类 号：TV135.2[水利工程—水力学及河流动力学]