Summary The unsteady reflection of dam-break flow along a horizontal channel by a remote barrier is modelled using the nonlinear shallow water equations. The interaction generates an upstream moving bore that connects the collapsing reservoir of fluid to a rapidly deepening fluid layer adjacent to the barrier. These motions are modified when the fluid is released into a channel containing a pre-wetted layer, because the oncoming flow is itself headed by a bore that alters the initial reflection. Solutions for these flows are calculated using quasi-analytical techniques that utilise the method of characteristics and the hodograph transformation of the governing equations, and the results are validated by comparison with direct numerical integration of the shallow water equations. The analytical solutions enable the precise identification of dynamical features in the flow, including the onset and development of discontinuous solutions that are manifest as bores, as well as their long term behaviour, the rate at which energy is dissipated, and for flows generated from the release of a finite reservoir, the maximum depth of the fluid layer at the barrier.

中文翻译：

---

溃坝反射

总结 使用非线性浅水方程模拟了远处障碍物沿水平通道的溃坝流的非定常反射。这种相互作用产生了一个上游移动孔，该孔将塌陷的流体储存器连接到与屏障相邻的快速加深的流体层。当流体被释放到包含预润湿层的通道中时，这些运动会被修改，因为迎面而来的流体本身是由改变初始反射的孔引导的。这些流量的解是使用准解析技术计算的，该技术利用特性方法和控制方程的全线变换，并通过与浅水方程的直接数值积分进行比较来验证结果。