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### Discontinuous Slope

Figure 88: Geometry of a discontinuous slope

The discontinuous slope is the upstream element of a pair of boundary elements simulating a change in slope. The corresponding downstream element is the discontinuous opening. Both are illustrated in Figure 88. The following constants have to be specified on the line beneath the *FLUID SECTION,TYPE=CHANNEL DISCONTINUOUS SLOPE card:

- the width
- (Figure 88; if the slope is calculated from the coordinates of the end nodes belonging to the element)
- the length (Figure 88; if the length is calculated from the coordinates of the end nodes belonging to the element)
- the trapezoid angle
- the grain diameter for the White-Colebrook law or the Manning constant for the Manning law (in the latter case the user has to specify the parameter MANNING on the *FLUID SECTION card)
- the number of the upstream reference element
- not used
- the number of the downstream discontinuous opening element
- not used

The length is typically small compared to the length of the adjacent channel branches. Since storage for 9 items is provided and only 8 entries are allowed per line, an extra blank line has to be provided for the ninth dummy item.

Notice that a discontinuous slope element generally has upstream channel elements attached to it. Therefore, it is always mandatory to specify an upstream reference element.

Example files: channel6.

Next: Discontinuous Opening Up: Fluid Section Types: Open Previous: Weir slope Contents