大型输水渠道闸前常水位的研究

南水北调中线输水渠道中,针对同时操作闸门是否仍能维持闸前水位为常值,模拟计算了同时改变渠首流量、闸门开度和分水口流量时渠道中的非恒定过渡过程。结果显示,中线主干渠中所有闸门开度不论是同时增加还是减小,渠道中的水流均需要很长时间才能达到新的恒定状态,且闸门开度减小比闸门开度增大所需的过渡时间要长很多。非恒定过渡过程中,闸前水位的变化幅度都较大,各闸前水位最终都能回复到初始时刻的水位。由于非恒定过渡过程时间很长,实际运行条件下,要实现闸前常水位运行方式还需要对闸门的调度方式做更多的研究。

Constant water levels at the upstream of sluice gates in a large-scale transferring channel

Aimed to study on whether constant water levels immediate at the upstream of control gates can be maintained in the Middle Route of South-to-North Water Transfer Project, the different unsteady flow transitional processes are simulated when inflow at the head, openings of control gates and the flow rates divided by outlets are changed simultaneously. The results show that a very long time is needed to reach a new steady state of the flow in the channel under operations of all control gate openings simultaneously and the transitional time needed for the decreasing of gate openings is much longer than that for their increasing. Water levels at the upstream of control gates vibrate to a big extent in transitional processes and can restore to their initial values finally. More studies are needed to find out the methods of gate operation that can fully realize constant water sur- face elevations immediate at the upstream of sluice gates for real-time channel regulations.