输水隧洞坡角对侧式进/出水口水力特性影响研究

抽水蓄能电站侧式进/出水口具有双向过流的特点,进/出水口自身体型参数对其水力特性具有很大的影响,但连接的输水隧洞布置型式也同样会影响进/出水口水力特性,若输水隧洞布置不恰当,将可能导致进/出水口出现不利的水力特性。利用RSM紊流模型,以某侧式进/出水口为研究对象,在进/出水口体型不变的前提下,研究出流工况不同隧洞坡角对进/出水口内部流态、拦污栅断面流速不均匀系数、水头损失系数及流量分配等水力特性的影响。结果表明,当隧洞坡角等于扩散段垂向扩散角时,进/出水口内部流态较好,反向流速区的沿程范围、拦污栅断面流速不均匀系数及水头损失系数均最小。因此,当进/出水口扩散段垂向扩散角不大且各隧洞坡角均满足地形、地质条件的情况下,隧洞坡角等于扩散段垂向扩散角时,可获得较优的水力特性。

Influences of the tunnel slope on the hydraulic characteristics of the side inlet/outlet

The side inlet/outlet of pumped storage power station has bidirectional flow characteristics.The shape parameters of the side inlet/outlet have a great influence on its hydraulic characteristics,though the layout of the connected water conveyance tunnel will also affect the hydraulic characteristics of the side inlet/outlet.If the layout of the water conveyance tunnel is not reasonable,it may lead to hydraulic characteristics adverse to the inlet/outlet.The paper investigated the influences of different tunnel slope on the hydraulic characteristics of the inlet/outlet on the condition of outflow using the turbulence model of RSM for a side inlet/outlet,given that the shape of the inlet and outlet remained the same. then The condition of outflow included the flow pattern,non-uniformity of flow velocity,the head loss coefficient and the flow distribution.The results showed that when the tunnel slope equaled the vertical diffusion angle of the diffusion section,the flow pattern in the inlet/outlet could be improved.The range and volume ratio of the reverse-flow velocity area was the smallest,non-uniformity coefficient of flow velocity and the head loss coefficient were the smallest.Therefore,when the vertical diffusion angle of the inlet/outlet diffusing section was not large and each tunnel slope satisfied the topography and geological conditions,the tunnel slope was equal to the vertical diffusion angle of the diffusing section to obtain better hydraulic characteristics.