进水口前立轴旋涡的数值模拟及消涡措施分析

Numerical Simulation of Vertical Vortex at Intake and the Analysis of Anti-swirl Method

原设计方案试验发现溢洪道进口产生串通旋涡,为消除有害旋涡,在环形堰口对称布置3个防涡墩,结果表明消涡效果良好,可有效降低堰上水位,增大流量系数。采用RNGk-ε紊流模型对有无防涡墩两种情况进行模拟,再现了漏斗状吸气旋涡,计算结果与测量数据吻合良好,验证了旋涡模拟的可行性。从环量的角度分析了防涡墩的消涡作用,发现旋涡的形成存在一个环量随时间递增的过程,而防涡墩的设置可大幅度减小水流环量。对旋涡稳定时水面环量和涡量的变化规律也进行了分析,随着半径的增大,环量相应增大,涡量则减小。

Model investigations of the primary design showed that the vertical vortex occurs at the intake of the shaft spillway. To eliminate the harmful vortex, three anti-swirl piers were set around the intake. Results indicated that the anti-swirl effect is good, the water level reduces and the discharge coefficient increases. The RNG k - ε turbulence model was used to simulate the conditions without and with the anti-swirl pier, and the funnel-shaped vertex was successfully simulated. The calculations are in agreement with the measurement data. The effect of the antiswirl pier was analyzed from the circulation angle. It was shown that the vortex formation accompanies the process of the increase of the circulation, and the circulation can be largely reduced by setting the anti-swirl piers. The circulation and vorticity of the water surface while the vortex is stable were also studied. With the increase of the radius, the circulation increases and the vorticity decreases.