The Junction unit is applied at the division of a single channel into several channels or the confluence of many channels into one. It may also be used to connect an open channel directly to a conduit if entry and exit losses are insignificant. It may also be used when adding bypass/overspill structures or adding structures in parallel.
Data
Field in Data Entry Form | Description | Name in Datafile |
|---|---|---|
Node 1 | First connecting node name | Label1 |
Node 2 | Second connecting node name | Label2 |
Theory and Guidance
The Junction models an open channel junction.
The Junction is applied at the division of a single channel into several channels or the confluence of many channels into one or both. It may also be used where structures in parallel or bypass/overspill structures are being modelled. The Junction may also be used to connect an open channel directly to a conduit if entry and exit losses are insignificant.
Equations
The equations used to model junctions are flow continuity:
|
|
and equality of water surface level:
|
|
General
Junctions must not be connected to other junctions or reservoirs.
Bifurcating junction outflows may be connected to Abstractions. The abstractions typically define logical rules to govern the split of flow.
Datafile Format
Line 1 - Keyword 'JUNCTION' [comment]
Line 2 - Keyword 'OPEN'
Line 3 - Labels for the junction (two or more)
