带长连接管的阻抗式调压室水击穿室影响研究

针对带有长连接管的阻抗式调压室的有压引水系统，研究了长连接管对水击穿室的影响，推导了水击穿室系数的理论公式，并基于工程实例进行了数值模拟验证。结果表明，当连接管长度小于引水隧洞的10%时，水击穿室系数、蜗壳末端最大压力、引水隧洞最大压力变化幅度分别在10%、1%、2%以内。因布置需求连接管长度超过引水隧洞的10%时，须对连接管的影响加以考虑，必要时对隧洞衬砌提出特殊要求。随连接管管径和阻抗孔孔径增大，水击穿室系数减小，其中阻抗孔孔径对水击穿室的影响更大；连接管与阻抗孔直径相等和连接管管径略大于阻抗孔孔径方案相比，当阻抗孔孔径较小时，前者能更明显地降低水击穿室系数，当阻抗孔孔径较大时，后者水击穿室系数更小。

Study on influence of throttled surge tank with long link pipe on water hammer passing through it

To study the pressure diversion system of a throttled surge tank connected to a long link pipe, the influence of the pipe length on water hammer passing through the tank was examined and derive an equation for the coefficient of water hammer was derived simulating a system of a case study project. With a link pipe shorter than 10% of the diversion tunnel length, water hammer coefficient, peak pressure at the end of volute, and peak pressure in the tunnel were found to vary in the ranges of 10%, 1% and 2% respectively. If the pipe length exceeds this 10% threshold under certain layout requirement, its influence should be considered and tunnel lining requirement be modified accordingly. The coefficient decreases with the increasing diameter of the link pipe or the impedance hole, depending more on the latter. For impedance holes with small diameters, the coefficient can be significantly reduced if the pipe takes the same diameter, whereas it is smaller if the pipe has a slightly larger size than the impedance hole for large impedance holes.