基于计算流体力学（CFD），对双机共用尾水调压室的几种典型工况进行了数值计算，得到调压室底流速分布、水头损失系数和水流通过两个阻抗孔流进（出）调压室的流量。通过分析各工况的模型内部流动状态，并与模型试验结果进行对比，发现：水流进（出）调压室水头损失系数随流量比增大而增大，且分流工况单台机组运行时损失系数值比两台机组运行时小；单机运行时，水流流经两个阻抗孔进（出）调压室的流量大小不一定相等，且随流量比变化而变化。

In this paper, computational fluid dynamics (CFD) method was used to simulate several typical working conditions of tailrace surge tanks shared by two units. The flow velocity distribution under the surge tank, head loss, and flow rate of water flowing into or out of the surge tank through the two impedance holes were obtained and analyzed. In addition, the simulated flow patterns under different working conditions were analyzed and compared with those obtained from experimental results. The results indicated that the head loss coefficient for water flowing into or out of the surge tank increases with the increasing of flow rate and the head loss coefficient under single-unit operation is lower than that under two-unit operation. Moreover, the flow rates of water flowing into or out of the surge tank through the two impedance holes shared by two units were not the same under single-unit operation and they were affected by the variation of discharge ratio.