渠道下游常水深运行非恒定流数值模拟研究

Numerical simulation of unsteady flow in canals operated with constant downstream water depth

为了研究闸门调控下的梯形渠段非恒定流过渡过程,在下游常水深运行条件下,采用矩形网格特征线法,对渠段上游来水量变化和渠段上游闸门在不同线性调节方式下引起的非恒定流过渡过程进行了数值模拟,研究了渠段上游来水量变化时下游流量、上游水深变化过程,探讨了渠段上游闸门在不同线性调节方式下上、下游流量和上游水深的变化过程。结果表明,当上游来水量变化时,下游流量和上游水深经历一段时间都趋于稳定,且流量变幅越大,趋于稳定的时间也越长。闸门按线性函数式调节开度后,闸门过流流量、上游水深基本按线性规律变化,而后基本维持稳定不变。

In order to research unsteady flow transition processes at trapezoidal canal reach with sluice gate controlling under the condition of constant downstream water depth operation,rectangular grid characteristic method was used, and unsteady flow transition processes caused by upstream discharge variation or sluice gate regulating at different linear modes were simulated. Downstream discharge and upstream water deep transition process were researched owing to variation of upstream incoming flow to the reach, discharge of upstream and downstream,upstream water deep transition process were studied due to upstream sluice gate regulating in different linear modes. Results showed when upstream discharge changed, downstream discharge and upstream water depth got gradually to a stable state after a certain time,and the larger the discharge variation, the longer the time interval needed for the flow to reach stable state. When gate was regulated with the given linear functions,discharge through the gate and upstream water depth varied basically in linear mode ,and then they basically maintained stable.