Abstract: A throttled surge tank is arranged downstream of a pumped storage power station, and the tailrace tunnel is connected with the connecting pipe through a bifurcated pipe and a bend. The layout pattern is special and the flow condition is complex. Considering the complexity of layout and the actual situation of engineering construction, this paper studies the flow regime and flow coefficient at the bottom of throttled surge tank with typical layout. The variation laws of flow velocity distribution, pressure distribution and coefficients of inflow and outflow at the bottom of throttled surge tank in different layout schemes are obtained.

Key words: surge tank, long connecting pipe, three-dimensional flow field numerical simulation, flow coefficient

摘要： 某抽水蓄能电站下游布置阻抗式调压室，尾水洞与连接管通过岔管和弯道连接，布置型式特殊，水流条件 复杂。考虑到带长连接管的阻抗式调压室布置复杂性和工程建设实际情况，研究了典型布置型式下的调压室底 部流态及流量系数，得出了不同布置方案下调压室底部水流流速分布、压力分布和进出流流量系数的变化规律。

关键词: 调压室, 长连接管, 三维流场数值模拟, 流量系数