摘要
采用Realizablek-ε模型对模型混流式水轮机全流道非定常湍流进行模拟。针对两种导叶开度,分析了原型泄水锥、加长型泄水锥和圆头型泄水锥对水轮机压力脉动的影响,分析结果表明:加长型泄水锥和圆头型泄水锥均可达到降低尾水涡带振动能量的目的,不同形式泄水锥的减振效果与水轮机的运行工况有关;改型泄水锥使泄水锥下方的最低压力值显著升高,涡带长度缩短,提高了水轮机的空化性能和运行稳定性能;圆头型泄水锥在提高水轮机空化性能方面优势更明显;改型泄水锥较原型泄水锥占据了更多的过流空间,但对水轮机的流量影响不明显。
Three-dimensional unsteady turbulent flow in the entire flow passage of the model francis hydraulic turbines is simulated by using the Realizable k-ε turbulence model.The influences on pressure oscillation in the francis hydraulic turbine with original runner cone,extended runner cone and round-top runner cone are analyzed under two operating conditions.The computational results show that the vibrational energy of vortex-rope in the draft tube with the extended runner cone and the round-top one is reduced and which one is better depends on the operating condition.The two improved runner cones are effective in improving the stability and cavitation performance by increasing the minimum pressure near the runner cone and decreasing the length of the vortex rope.The round-top runner cone has advantage over the extended one in improving the cavitation performance.The flow discharges with the two improved runner cones are almost the same as that with the original one despite the occupation of the flow area.
出处
《中国农村水利水电》
北大核心
2010年第12期156-159,共4页
China Rural Water and Hydropower
基金
国家自然科学基金资助项目(51079106)
中央高校基本科研业务费专项资金资助(2103002)
关键词
混流式水轮机
压力脉动
泄水锥
数值模拟
francis hydraulic turbine
pressure oscillation
runner cones
numerical simulation
作者简介
钱忠东（1976-），男。教授，主要从事水力机械及水力学研究。E—mail：zdqian@whu．edu．cn。
