Discontinuous slope

Due to a change in slope the fluid depth changes. For small slope changes this effect is usually neglegible. For variations in $\varphi$ such that $\cos(\varphi)$ changes significantly, the fluid depth will change according to

$$Q=b h \sqrt{2 g (E-h \cos \varphi)},$$ (189)

assuming the mass flow and specific energy remain constant (no loss). For instance, a significant decrease of slope will lead to a fluid depth increase if the flow is supercritical and a decrease if it is subcritical.

The following constants have to be specified on the line beneath the *FLUID SECTION,TYPE=DISCONTINUOUS SLOPE card:

• width of the channel.
• trapezoidal angle of the channel.
• not used.
• the slope $S_0 = \sin \phi, -1<S_0<1$ at node 1 (first node in the topology of the element; for this element the slope must be given explicitly and is not calculated from the coordinates of the end nodes belonging to the element).
• the slope $S_0 = \sin \phi, -1<S_0<1$ at node 2 (thrid node in the topology of the element; for this element the slope must be given explicitly and is not calculated from the coordinates of the end nodes belonging to the element).

Example files: channel7.